JP2001083652A - Method for preparing nonphotosensitive fatty acid silver salt grains and preparing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the nonphotosensitive fatty acid salt grains superior in dispersion stability and coatability at the time of dispersing them and to enhance a heat-developable photosensitive material manufactured by using this dispersed material in fog prevention ability after storage and image stability and light transmittance after heat-development processing. SOLUTION: The fatty acid silver salt grains are prepared by reacting an aqueous solution containing silver ions with a solution of a fatty acid alkali metal salt in water and an organic solvent or a mixture of water and an organic solvent and at that time, the solution of the above fatty acid alkali metal salt and the aqueous solution of the above silver ions are reacted in a gas-tight mixing means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing non-photosensitive fatty acid silver salt particles for use in a photothermographic material and an apparatus for preparing the non-photosensitive fatty acid silver salt particles for performing the method. It is.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand in the medical field to reduce the amount of waste liquid from the viewpoint of environmental protection and space saving. Thus, a photothermographic material for medical diagnostics and photographic technology, which can be efficiently exposed by a laser imagesetter or laser imager and can form a sharp black image having high resolution and sharpness. There is a need for technology for developed photographic materials. These photothermographic materials can eliminate the use of solution processing chemicals and provide a simpler and more environmentally friendly thermal development system to customers.

A method of forming an image by thermal development is described in, for example, US Pat. No. 3,152,904 and US Pat.
7,075, and D.C. Crosta Bohr (Klost
Erboer), "Thermally Processed SilverSystems" (Imagining Processes and Materials (Imagin)
gProcesses and Materials) Neblette 8th edition, J. Sturge, V.S. Walworth,
A. Edited by Shepp, Chapter 9, page 279,
1989).

[0004] Such photosensitive materials include a reducible non-photosensitive silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), and a silver reducing agent, usually in an organic binder matrix. It is contained in a dispersed state.
The photosensitive material is stable at room temperature, but after exposure to high temperature (for example,
When heated to 80 ° C. or higher, silver is generated through an oxidation-reduction reaction between a reducible silver source (functioning as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas and allows the formation of an image.

The silver source used in such a system is generally a silver salt of a fatty acid, and various production methods are known. For example, Japanese Patent Application Laid-Open Nos.
9-94619 and JP-A-53-68702.
JP-A-53-31611, JP-A-54-4117, and JP-A-54-467, a method for preparing an organic silver salt in a coexisting solution of water and a poorly water-soluble solvent as disclosed in
A method for preparing an organic silver salt in an aqueous solution as described in JP-A-09-09, JP-A-57-186745 and JP-A-47-9
No. 432 and US Pat. No. 3,700,458, for example, a method of preparing an organic silver salt in an organic solvent. Basically, it is prepared by heating and melting the fatty acid in water at or above its melting point, adding sodium hydroxide or an alkali metal salt with vigorous stirring, and then adding silver nitrate to replace the alkali soap with silver soap. .

[0006] Such an alkali soap forms micelles in an aqueous solution, and is apparently a cloudy liquid. Such a reaction from the micellar state to silver soap often causes production stability problems. For this reason, as a method for making the alkaline soap a uniform liquid, it has been proposed to use a mixed solution of water and alcohol as a solvent in JP-A-55-4060.
No. 7 discloses this.

[0007] Alkali soap exhibits alkalinity as its name suggests. Therefore, in this case, the silver soap will be made at a high pH. However, the addition of silver nitrate to an alkaline solution not only generates silver oxide as a by-product, but also has a high reducing property due to the high pH of reducing contaminants inevitable in production. This results in unintended silver nuclei. Such by-products are a significant disadvantage in the performance of such heat-developable photographic materials, in particular in producing undesirable fog. From the above viewpoint, the fogging problem has not been solved even in the method described in JP-A-55-40607 for the purpose of obtaining a uniform liquid in order to suppress the generation of by-products.

Japanese Patent Application Laid-Open No. 9-127643 discloses a method for forming a silver salt by simultaneous metered addition of an alkali metal salt solution and a silver nitrate solution. A mixed solution of sodium behenate in water and isopropyl alcohol and silver nitrate are disclosed. There is a description of simultaneous addition with a solution. This method is at least high p
Although the reaction under H can be reduced to a neutral region and is a preferable method for reducing the amount of silver oxide formed, isopropyl alcohol has a weak reducing property. I can't.

As described above, care must be taken in the preparation of the fatty acid silver salt, and it is necessary to eliminate as much reducing substance as possible during the formation of the fatty acid silver salt, control the particle size, and control the particle shape. There is, however, not that far with conventional methods.

By the way, most heat developing materials using a silver salt of a fatty acid form a photosensitive layer by applying a coating solution using an organic solvent such as toluene, methyl ethyl ketone or methanol as a solvent. Using an organic solvent as a solvent is not only extremely disadvantageous in terms of cost due to safety in the manufacturing process, adverse effects on the human body, and further recovery of the solvent, but also a photothermographic material aiming at environmental protection. Considering the purpose of providing the world, it is not an appropriate manufacturing method.

For this reason, a method of forming a photosensitive layer using a coating solution of an aqueous solvent has been considered. For example, JP
JP-A-52626 and JP-A-53-116144 disclose examples using gelatin as a binder. Japanese Patent Application Laid-Open No. 50-151138 discloses an example in which polyvinyl alcohol is used as a binder.

Further, Japanese Patent Application Laid-Open No. 60-61747 discloses an example in which gelatin and polyvinyl alcohol are used in combination. As another example, see JP-A-58-28.
No. 737 describes an example of a photosensitive layer using a water-soluble polyvinyl acetal as a binder.

The use of a water-soluble binder makes it possible to form a photosensitive layer using a coating solution of a water solvent, which has great environmental and cost advantages. However, the binder of the water-soluble polymer is incompatible with the fatty acid silver salt, so that a coating film that can withstand practical use cannot be obtained due to the coating surface quality, or the silver color tone of the developed part is brown which is far from black which is originally preferred. However, since problems such as yellowing, high fog, and the like occur, only products with significantly impaired commercial value were obtained.

In order to obtain a practically usable coating surface quality with an aqueous solvent coating solution containing a fatty acid silver salt, it is necessary to keep the fatty acid silver salt in a water solvent in a finely dispersed state without aggregation.
Therefore, it is necessary to develop a method for dispersing the fatty acid silver salt in fine particles. Usually, for example, D. Klooste
rboer) (Imaging Processes and Material
s) A dispersion of hydrophobic fatty acid silver salt particles as described in Neblette 8th edition, Sturge, V. Walworth, edited by A. Shepp, p. 279, 1989). After formation, the mixture is separated by filtration, taken out as a solid, and then mixed with a dispersant and redispersed.

The method of dispersing the fatty acid silver salt in the form of fine particles can be carried out by a known fine-granulating means (for example, a high-speed mixer, a homogenizer, a high-speed impact mill, a Banbury mixer, a homomixer, a kneader, a ball mill, a vibrating ball mill) in the presence of a dispersing aid. , Planetary ball mill, attritor, sand mill,
(Bead mill, colloid mill, jet mill, roller mill, tron mill, high-speed stone mill) are known to mechanically disperse. However, in these methods, there are many agglomerated particles, resulting in poor coated surface quality. Not only is it possible to obtain a stable coating solution, but also it is highly probable that the primary particles of fatty acid silver, which were originally crystallized as a poorly water-soluble salt, are indiscriminately pulverized. It will be the cause.

Further, Japanese Patent Publication No. Hei 7-199553, Japanese Patent Application Laid-Open No. Hei 8-137404, and Japanese Patent Application Laid-Open No. Hei 8-238848.
Japanese Patent Application Laid-Open Publication No. H11-163873 discloses a method of finely dispersing a fatty acid silver salt by pressure treatment, but these methods relate to a dispersion using an organic solvent as a solvent, and have different characteristics from the solution of the above problem. It is.

JP-A-9-127643 discloses a method of directly desalting a fatty acid silver salt particle dispersion obtained by simultaneous metered addition of an alkali metal salt solution and a silver nitrate solution using dialysis or ultrafiltration. Have been. This method is a preferable method in that at least the primary particles obtained during crystallization of the fatty acid silver salt are directly introduced into the photosensitive layer without damaging the particles, but the aggregation of particles and the dispersion in a high salt concentration atmosphere are concentrated. However, the problem of increasing the viscosity during the process has not been solved, and in this regard, there is no means for obtaining a practical coating solution.

Further, in order to obtain fine and monodispersed fatty acid silver salt particles, it is necessary to mix vigorously while adding an alkali metal salt solution and a silver nitrate solution. Particularly, a solution of an alkali metal salt of a fatty acid dissolved at a high temperature drops and precipitates at the moment of its addition, so that if the dilution rate or the flow is slow, it grows into large coarse particles. However,
When adding to a tank having a gas / liquid interface, if the stirring speed is increased, air entrainment occurs. The fatty acid silver salt particles are extremely hydrophobic, adsorbing on the surface of the entrained foam, stabilizing the foam and preventing the foam from breaking, and causing adjacent particles on the foam to aggregate. The liquid entrained in this way becomes whipped cream, and when desalting by-product salts by ultrafiltration, not only the handling properties are significantly deteriorated, but also the aggregated particles cause clogging. .

If the liquid temperature after the reaction of the silver ion solution and the alkali metal salt solution of the fatty acid is high, the particles grow by physical ripening, so that the temperature is preferably maintained at about room temperature. On the other hand, in order to obtain a stable solution of a long-chain fatty acid alkali metal salt, 50
It is necessary to raise the temperature to at least ℃, and it is necessary to quickly perform heat exchange to offset the amount of heat brought by the additive liquid. In the method in which a jacket tank is attached to a tank or the like, the amount of the reaction solution increases, and the surface area for heat exchange decreases.

As described above, no stable production method for liquefying a silver salt of a fatty acid in an aqueous solvent with good coating surface quality and excellent optical properties such as haze and fog has not been found.

[0021]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. That is, the present invention provides non-photosensitive fatty acid silver salt particles having excellent dispersion stability and coating suitability when formed into a dispersion, and the photothermographic material produced using the dispersion can prevent fog even after storage. High performance, and furthermore, image stability after thermal development processing,
An object of the present invention is to provide a method for preparing non-photosensitive fatty acid silver salt particles having a feature of excellent light transmittance.

[0022]

The present inventors have made intensive studies to solve these problems, and as a result, a silver ion-containing aqueous solution and a fatty acid alkali metal salt solution are mixed and reacted in a closed mixing means. As a result, it has been found that excellent non-photosensitive fatty acid silver salt particles can be prepared, and the present invention has been provided. The term "closed mixing means" as used herein refers to a means for stirring and mixing liquids in a state where the inside of the container is filled with the liquid to be mixed and substantially no air phase exists, that is, there is no so-called gas / liquid interface. That is, the present invention
Silver ion-containing particles obtained by reacting a silver ion-containing solution containing water or a mixture of water and an organic solvent as a solvent, and a fatty acid alkali metal salt solution containing water, an organic solvent, or a mixture of water and an organic solvent as a solvent. In which the silver ion-containing solution and the fatty acid alkali metal salt solution are mixed and reacted in a closed mixing means. In the method for preparing non-photosensitive fatty acid silver salt particles of the present invention, it is preferable to further add water or a mixture of water and an organic solvent into the closed mixing means. In particular, it is preferable that the added water or the mixture contains a dispersant. It is also preferable that at least a part of the mixture obtained after the reaction is circulated and added to the closed mixing means. Furthermore, it is also preferable to cool the mixture obtained in the reaction word.

The present invention also provides a first supply means for supplying a silver ion-containing solution using water or a mixture of water and an organic solvent to a closed mixing means; water, an organic solvent, or a mixture of water and an organic solvent; A second supply means for supplying a solution of the fatty acid alkali metal salt using the mixture as a solvent to the closed mixing means; a third supply means for supplying water or a mixture of water and an organic solvent to the closed mixing means; A non-photosensitive fatty acid silver salt, comprising: a supply means, a closed mixing means for mixing the supplies from the second and third supply means and discharging a liquid containing non-photosensitive fatty acid silver salt particles. An apparatus for preparing particles is also provided. This preparation apparatus preferably further has a cooling means for cooling the liquid containing non-photosensitive fatty acid silver salt particles discharged from the closed mixing means. Furthermore, the present invention
A first supply unit for supplying a silver ion-containing solution using water or a mixture of water and an organic solvent as a solvent to a closed mixing unit;
A second supply unit for supplying a solution of a fatty acid alkali metal salt using water, an organic solvent, or a mixture of water and an organic solvent as a solvent to the closed mixing unit; the first supply unit, the second supply unit, and a third supply unit Closed mixing means for mixing the supply from the supply means and discharging the non-photosensitive fatty acid silver salt particle-containing liquid; and at least a part of the non-photosensitive fatty acid silver salt particle-containing liquid discharged from the closed mixing means. An apparatus for preparing non-photosensitive fatty acid silver salt particles, further comprising a third supply means for supplying to the closed mixing means is also provided. This preparation apparatus preferably further has a cooling means for cooling the liquid containing non-photosensitive fatty acid silver salt particles discharged from the closed mixing means. Further, the closed mixing means is preferably a mixing device having rotating blades in a closed vessel, the linear velocity at the outermost peripheral portion of the rotating blades is 1 to 50 m / sec, and the stirring power for 1 liter of mixed liquid is 0.1 to Preferably, it is 10 kW. In this specification, “to” means a range including the numerical values described before and after it as a minimum value and a maximum value, respectively.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The method for preparing the non-photosensitive fatty acid silver salt particles of the present invention will be described in detail below. The method for preparing non-photosensitive fatty acid silver salt particles of the present invention is a silver ion-containing solution using water or a mixture of water and an organic solvent as a solvent,
Water, an organic solvent, or a fatty acid alkali metal salt solution containing a mixture of water and an organic solvent as a solvent to prepare fatty acid silver salt particles, wherein the silver ion-containing solution is contained in a closed mixing means. And the fatty acid alkali metal salt solution are mixed and reacted. In the preparation method of the present invention, a plurality of closed mixing means may be arranged in parallel.
FIG. 1 is a schematic view of a method for preparing a non-photosensitive fatty acid silver salt according to the present invention. 1 is a closed and liquid-filled mixing device,
2 is a heat exchanger. In the figure, A is a silver ion-containing solution, B is a fatty acid alkali metal salt solution, and C is water, a mixture of water and an organic solvent, or a mixed solution containing non-photosensitive fatty acid silver salt particles after reaction. These liquids join in the mixing device to prepare a fatty acid silver salt liquid D, and then heat exchanger 2
And cooled.

FIG. 2 shows an embodiment of the method for preparing a non-photosensitive fatty acid silver salt according to the present invention. In the drawing, storage tanks 11 and 12 store a silver ion-containing solution and a fatty acid alkali metal salt solution at a predetermined temperature, respectively. The flowmeters 13 and 14 are flowmeters for measuring the flow rates when these solutions are added to the closed and liquid-filled mixing device 18 via the pumps 15 and 16. In this embodiment, as a third component, a pump 17 for re-supplying the prepared fatty acid silver salt particle dispersion to the mixing device 18
Is provided. The liquid after the reaction in the mixing device 18 is:
The liquid is introduced into the heat exchanger 19, rapidly cooled, and led to the product liquid tank 20.

FIG. 3 shows another embodiment of the method for preparing a non-photosensitive fatty acid silver salt according to the present invention. In the figure, the storage tank 21
In Nos. 22 to 22, the silver ion-containing solution and the fatty acid alkali metal salt solution are stored at a predetermined temperature. The flow meters 23, 23 ', 24, 24' control the flow rates at which these solutions are added via the pumps 25, 25 ', 26, 26' to the closed and liquid-filled mixing devices 28, 28 '. It is a flow meter for measurement. In this embodiment, as the third component, the prepared fatty acid silver salt particle dispersion is supplied to the mixing device 28, 28 'again by the pump 27,
27 '. The liquid that has completed the reaction in the mixing devices 28 and 28 ′ is introduced into the heat exchanger 29, rapidly cooled, and guided to the product liquid tank 30. Thus, one closed mixing means or two or more closed mixing means may be arranged in parallel. When two or more are arranged in parallel, the solution may be equally supplied to each closed mixing means. The silver ion-containing solution and the fatty acid alkali metal salt solution to be added may each be prepared in a storage tank and set at a predetermined temperature, or separately prepared and then supplied to the storage tank and set to a predetermined temperature. Is also good.

The type of heat exchanger used in the present invention is not limited. For example, a multi-tube cylindrical heat exchanger, a heat pipe type heat exchanger, a double tube type heat exchanger, a coil type heat exchanger, a cascade type heat exchanger, a spiral plate type heat exchanger and the like can be effectively used. As the flow meter for the silver ion solution, an electromagnetic flow meter or a mass flow meter having a measurement error of less than 1% and a time coefficient of less than 1 second can be used. As the flow meter for the organic acid metal salt solution, a mass flow meter having a measurement error of less than 1% and a time coefficient of less than 1 second can be used. As the pump, a pump (for example, a rotary pump, a sanitary pump, a gear pump, a mono pump, a plunger pump, a diaphragm pump) capable of performing feedback control based on the measurement value of the flow meter, or a stable discharge with a quantitative error of less than 1% Pumps (for example, gear pumps, mono pumps, plunger pumps, diaphragm pumps) capable of obtaining an amount. Preferably, the pulsation rate is less than 5%.

The pH of the silver ion-containing solution used in the present invention
Is preferably pH 1 to 6, more preferably pH 1.
5-4. Further, acids and alkalis can be added for pH adjustment. The type of acid and alkali is not particularly limited.

The silver ion concentration of the silver ion-containing solution used in the present invention is arbitrarily determined.
03-6.5 mol / L is preferable, and 0.1-5 mol / L
L is more preferred.

In order to form the fatty acid salt particles of the present invention, at least one of a silver ion-containing solution, a fatty acid alkali metal salt solution, and a solution prepared in advance in a reaction field contains a fatty acid alkali metal salt. Rather than coalescing or micelles, it must contain an amount of organic solvent that can result in a substantially clear solution. The solution may be an organic solvent alone, but is preferably a mixed solution with water.

The type of the organic solvent used in the present invention is not particularly limited as long as it is water-soluble and has the above-mentioned properties. However, it is not preferable that the organic solvent interferes with photographic performance. Preferred are alcohols, acetone, and more preferably tertiary alcohols having 4 to 6 carbon atoms. In addition, the fatty acid used is relatively stable to light when formed into a silver salt, but in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent,
A silver salt that forms a silver image when heated to 80 ° C. or higher. Fatty acids are in particular long-chain fatty carboxylic acids having 10 to 30 carbon atoms, preferably 12 to 26 carbon atoms.
Preferred examples of the aliphatic carboxylic acid include cerotic acid,
Lignoceric acid, behenic acid, erucic acid, arachidic acid,
Stearic acid, oleic acid, lauric acid, caproic acid,
Myristic acid, palmitic acid, maleic acid, fumaric acid,
Mention may be made of tartaric acid, linoleic acid, butyric acid and camphoric acid, and mixtures thereof.

As the alkali metal of the alkali metal salt of a fatty acid used in the present invention, specifically, Na and K are preferable. Alkali metal salts of fatty acids include NaOH or KO as fatty acids.
Prepared by adding H. At this time, it is preferable to make the amount of alkali less than or equal to the equivalent of fatty acid so that unreacted fatty acid remains. In this case, the amount of the residual fatty acid is 3 to 50 mol% based on the total fatty acid, and preferably 3 to 50 mol%.
３０30 mol%. Alternatively, after the alkali is added in a desired amount or more, an acid such as nitric acid or sulfuric acid may be added to neutralize excess alkali.

Further, the silver ion-containing solution and the fatty acid alkali metal salt solution used in the present invention, or the solution of the closed mixing apparatus to which both solutions are added, may be used as a dispersant, for example, by the general formula of JP-A-62-65035. A compound represented by (1), a water-soluble group-containing N-heterocyclic compound described in JP-A-62-150240,
Inorganic peroxides as described in JP-A-10-1019, sulfur compounds as described in JP-A-51-78319, disulfide compounds as described in JP-A-57-643, and Hydrogen peroxide or the like can be added.

In the alkali metal salt solution of fatty acid used in the present invention, the amount of the organic solvent is preferably from 3 to 70%, more preferably from 5 to 50%, as the solvent volume based on the volume of water. At this time, since the optimum solvent volume changes depending on the reaction temperature, the optimum amount can be determined by trial and error.

The concentration of the alkali metal salt of a fatty acid used in the present invention is 5 to 50% by mass, preferably 7 to 45% by mass, more preferably 10 to 40% by mass.
% By mass.

The desired fatty acid silver salt can be prepared by simultaneously adding the silver ion-containing solution and the fatty acid alkali metal salt solution used in the present invention to the closed mixing means.
At this time, it is preferable that 10 to 100% of the total amount of added silver is added at the same time as a solution of the alkali metal salt of a fatty acid having substantially the same mole, more preferably 30 to 100% is added simultaneously. % Is particularly preferred. When any of them is preferentially added, it is preferable to precede the solution containing a silver ion.

The silver ion-containing solution and the fatty acid alkali metal salt solution used in the present invention can be adjusted to an appropriate temperature in order to obtain desired particles. The temperature of the silver ion-containing solution is preferably 5 to 60 ° C. for the purpose of ensuring the stability of the solution,
More preferably, it is 5 to 40C. The fatty acid alkali metal salt solution is kept at 50 to 90 ° C. in order to keep the temperature range necessary for avoiding the phenomenon of alkali soap crystallization and solidification.
Is preferable, and 60 to 85 ° C is more preferable. The tank for storing each solution preferably has means for keeping the temperature at such a temperature.

There are various approaches to forming fatty acid silver salt particles according to the present invention. In order to obtain fatty acid silver salt particles, it is preferable to reduce the solubility of the fatty acid silver salt in the reaction field. According to the study of the present inventors, it has been revealed that the fatty acid silver salt particles tend to decrease in size as the reaction time increases. In order to obtain the desired particle size, it is necessary to determine the reaction time by trial and error.

The apparatus for adding the reaction solution is not limited. In particular, the closed mixing device used in the present invention is, for example, a bulk stirrer such as an anchor blade or a paddle blade, an emulsifier / disperser such as a dissolver or a homogenizer, a static mixer such as a static mixer or a sluzer mixer, or a combination thereof. Any method can be used.

When mixing the liquids, if the stirring power is too small, sufficient mixing will not be performed, and if the stirring power is too large, heat generation and cavitation will occur. For this reason, the stirring power has a preferable range. In a mixing device having a rotating blade, the linear velocity at the outermost peripheral portion of the rotating blade is preferably 1 to 50 m / sec, more preferably 1 to 30 m / second.
/ Second, and the stirring power consumed per unit volume of the liquid is preferably 0.1 to 10 kW / L, more preferably 0.1 to 10 kW / L.
5 to 5 KW / L. As means for suppressing cavitation, the dissolved air in the liquid may be reduced, or the pressure in the mixing device may be set to 0.1 to ² kgf / cm ^{2 with} respect to the atmospheric pressure.
A method of increasing the degree can also be adopted.

The material of the closed mixer is not particularly limited as long as it has appropriate mechanical strength, but a material inert to the silver ion solution, the alkali metal salt solution of the fatty acid and the organic solvent used is preferable. In addition, since the alkali metal salt solution of the fatty acid is usually at a high temperature of 50 ° C. or higher, it is necessary to select a thermally stable material. Stainless steel materials (SUS304, SUS3
16), metal materials coated with titanium or a titanium alloy, glass lining, ceramic, fluororesin, etc.
Composite resin such as glass fiber and Kevlar,
Engineering plastics such as polyacetal and modified polyphenylene oxide;

The order of adding the silver ion solution (Solution A) and the alkali metal salt solution of the fatty acid (Solution B) is, for example, a method of adding the two solutions A and B to the same closed mixing apparatus. Add the remaining 1
A method of adding the liquid and a method of adding both the liquids A and B upstream of the closed mixing apparatus can be adopted. In addition to the above two liquids A and B, water or a mixed liquid of an organic solvent and water used in a silver ion liquid and an alkali metal salt liquid of a fatty acid, or a non-photosensitive fatty acid silver salt particle liquid after the reaction. Liquid 3 (liquid C)
Is added to the same closed mixer, two of the three liquids A, B and C are added in an arbitrary order upstream of the closed mixer and the remaining one liquid is added to the closed mixer. A method in which the three liquids A, B, and C are added upstream of the closed mixing apparatus can also be adopted. Further, a plurality of closed mixers are arranged in series, and one or two liquids are added to each of them (for example, the liquid A is added to the first closed mixer, and then the second liquid is added).
The method of adding the liquid B to the closed mixing apparatus of the above (1), the liquid A and the liquid B are added to both the first closed mixing apparatus and the second closed mixing apparatus thereafter.
Any method can be adopted, such as a method of adding a liquid, a method of adding the liquid A to the first closed mixing apparatus, and then adding the liquid A and the liquid B to the second closed mixing apparatus.

The addition time of the silver ion solution and the alkali metal salt solution of the fatty acid can be arbitrarily selected. For example, the addition may be performed at a constant addition rate, or in an acceleration or deceleration mode by an arbitrary time function.

In order to quickly lower the liquid temperature after the reaction between the silver ion solution and the alkali metal salt solution of the fatty acid, the silver ion solution to be supplied to the mixing device, water or a mixture of water and an organic solvent or In addition to the method of cooling the subsequent fatty acid silver salt particle liquid in advance, a method of cooling the mixing device itself or a method of providing a heat exchanger between the mixing device and the tank can be adopted. The temperature of the solution after the reaction of the silver ion solution and the alkali metal salt solution of the fatty acid is preferably 5 to 70 ° C, more preferably 10 to 50 ° C, and particularly preferably 20 to 45 ° C. Further, the cooling rate is set to 0.05 after the reaction liquid meets.
It is preferable to reach the target temperature in seconds to 10 seconds, preferably 0.05 to 5 seconds, more preferably 0.05 to 1 second.

The prepared fatty acid silver salt particles are led to a product liquid tank after being cooled. The product liquid tank is preferably stirred and mixed to make the reaction liquid uniform. As the stirring and mixing means here, for example, a bulk stirrer such as an anchor blade, a paddle blade, a dissolver,
Any system such as an emulsifying / dispersing machine such as a homogenizer, a static mixer such as a static mixer, a through mixer, or a combination thereof can be used.

The equivalent spherical diameter of the fatty acid silver salt particles prepared according to the present invention is preferably from 0.1 to 0.8 μm.
More preferably, it is 0.1 to 0.6 μm. Further, the long side / short side of the particles is preferably 1 to 4, more preferably 1 to 3, and particularly preferably 1 to 2. Further, the aspect ratio of the particles (particle size of the main plane (equivalent circle diameter) / particle thickness) is preferably from 2 to 30, and more preferably from 2 to 15. Further, the thickness of the particles is preferably from 0.01 to 0.20 μm, more preferably from 0.01 to 0.15 μm. The particle satisfying the above requirements is calculated as 3
The content is preferably 0 to 100%, more preferably 50 to 100%, particularly preferably 70 to 100%.

The particle size distribution of the fatty acid silver salt is preferably as monodispersed as possible. Assuming that the coefficient of variation is 100 times the value obtained by dividing the standard deviation of the particle diameter by the particle diameter, the coefficient of variation of the particle size of the fatty acid silver salt particles is preferably 20% or less, more preferably 18% or less, and still more preferably 15%. It is as follows. As a measuring method, for example, the particle size (volume weight average diameter) obtained by irradiating a fatty acid silver salt dispersed in a liquid with a laser beam and obtaining an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained. (So-called dynamic light scattering method).

A water-soluble dispersant can be added to the silver ion-containing solution and the fatty acid alkali metal salt solution or the reaction solution used in the present invention. Therefore, it can be added to the reaction solution at the time of forming the fatty acid silver salt, a separately prepared dispersant solution, and the solution after the formation of the fatty acid silver salt. The type of the dispersant is not particularly limited as long as it can disperse the formed fatty acid silver salt. Specific examples are in accordance with the description of the fatty acid silver salt dispersant described below.

The fatty acid silver salt which can be used in the present invention has a small particle size and a method of forming a solid fine particle dispersion using a dispersing agent in order to obtain fine particles without aggregation. When preparing this solid fine particle dispersion, it is preferable that the formed particles are not broken and only aggregation is eliminated. This can be determined by comparing the TEM photograph of the particles before washing with the TEM photograph of the particles after dispersion. In the particles prepared by the method of the present invention, when comparing the average particle size before water washing and the average particle size after dispersion, the projected area preferably does not change by 30% or more, and does not change by 20% or more. More preferably, no change of 10% or more is particularly preferable. As the dispersion method, it is preferable to use a method of converting the aqueous dispersion of the fatty acid silver salt into a high-pressure / high-speed stream and then reducing the pressure.

Further, when a photosensitive silver salt is coexisted at the time of dispersion, fog increases and the sensitivity is remarkably reduced. Therefore, it is more preferable that the photosensitive silver salt is not substantially contained at the time of dispersion. In the present invention, the amount of the photosensitive silver salt in the aqueous dispersion to be dispersed is 0.1 mol per mol of the fatty acid silver salt in the liquid.
% Or less, and no positive addition of a photosensitive silver salt is performed.

In the present invention, the dispersing apparatus and the technique used for carrying out the dispersing method as described above are described in, for example, "Dispersion Rheology and Dispersion Technology" (Toshio Kajiuchi and Hiroki Usui, 1991, Shin Yamasha Publishing Co., Ltd., p35
7-403), "Progress in Chemical Engineering, Vol. 24" (edited by the Society of Chemical Engineers, Tokai Branch, 1990, Maki Shoten, p. 184)
To 185), the dispersion method of the present invention is based on a method in which an aqueous dispersion containing at least a fatty acid silver salt is pressurized by a high-pressure pump or the like and fed into a pipe, and then a narrow slit provided in the pipe. And then a sharp drop in pressure is applied to the dispersion to perform fine dispersion.

The high-pressure homogenizer to which the present invention relates is generally (a) a "shearing force" generated when the dispersoid passes through a narrow gap at a high pressure and a high speed, and (b) a dispersoid is changed from a high pressure to a normal pressure. It is considered that dispersion into fine particles is performed by a dispersing force such as “cavitation force” generated when the particles are released. An example of this type of dispersing device is a Gaulin homogenizer. The particles collide and are emulsified and dispersed by the impact force. Working pressure is generally 1
00~600kg / cm ^2, the flow rate is in the range of a few M～30m / sec, be devised that the high-speed flow portion in order to increase the dispersion efficiency was devised such increasing the number collisions in the saw-toothed I have. On the other hand, devices capable of dispersing at higher pressures have been developed in recent years, and typical examples thereof include a microfluidizer (Microfluidics International Corporation) and a nanomizer (Tokusai Kika Kogyo Co., Ltd.) ).

The fatty acid silver salt particles prepared by the preparation method of the present invention can be dispersed to a desired particle size by adjusting the flow rate, the pressure difference at the time of pressure drop, and the number of treatments. From the point that the flow velocity is 200m /
Seconds to 600 m / s, differential pressure at the time of pressure drop is 900 to 300
0 kg / cm ² is preferable, and the flow rate is 300
m / sec to 600 m / sec, the differential pressure during pressure drop is 1500 to
More preferably, it is in the range of 3000 kg / cm ² . The number of times of the distributed processing can be selected as needed. Usually 1
A range of 10 to 10 times is selected, but about 1 to 3 times is selected from the viewpoint of productivity. It is not preferable to raise the temperature of such an aqueous dispersion under high pressure from the viewpoint of dispersibility and photographic properties.
At a high temperature exceeding ℃, the particle size tends to increase and fog tends to increase. Therefore, in the present invention, a cooling device is included in the step before the conversion to the high-pressure and high-speed flow, the step after the pressure is reduced, or both of the steps, and the temperature of such water dispersion is reduced by 5% by the cooling step. It is preferable that the temperature is maintained in the range of from 0 to 90 ° C, more preferably in the range of from 5 ° C to 80 ° C, and particularly preferably in the range of from 5 ° C to 65 ° C. In particular, at the time of high-pressure dispersion in the range of 1500 to 3000 kg / cm ² , it is effective to provide the above cooling step. As the cooling device, a device using a static mixer for a double tube or a triple tube, a multi-tube heat exchanger, a coiled tube heat exchanger, or the like can be appropriately selected according to the required heat exchange amount. Further, in order to increase the efficiency of heat exchange, it is only necessary to select a suitable one such as the thickness, wall thickness and material of the pipe in consideration of the working pressure. The refrigerant used for the cooler is 20 ° C
Well water or cold water treated with a refrigerator at 5 to 10 ° C, or a refrigerant such as ethylene glycol / water at -30 ° C as needed can be used.

Examples of the dispersant include synthetic anionic polymers such as polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, a maleic acid monoester copolymer, and an acryloylmethylpropanesulfonic acid copolymer. Semi-synthetic anionic polymers such as carboxymethyl starch and carboxymethyl cellulose; anionic polymers such as alginic acid and pectic acid;
No. 716, WO88 / 04794, etc., anionic surfactants, compounds described in JP-A-9-179243, known anionic, nonionic, cationic surfactants and other polyvinyl compounds Known polymers such as alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose, and naturally occurring polymer compounds such as gelatin can be appropriately selected and used. The concentration of the dispersant is preferably in the range of 1 to 30% by mass, more preferably 3 to 20% by mass, based on the fatty acid silver salt. The prepared dispersion is stored with stirring for the purpose of suppressing sedimentation of fine particles during storage, or stored in a highly viscous state by a hydrophilic colloid (for example, in a jelly state using gelatin). You can also.
Further, a preservative can be added for the purpose of preventing the propagation of various bacteria during storage.

The dispersion of fatty acid silver salt particles prepared by the method of the present invention comprises at least a fatty acid silver salt and water. The ratio between the fatty acid silver salt and water is not particularly limited, but when considering efficient coating film formation, the rheological properties for performing stable coating, and the production speed determined by the amount of dry moisture, You need to decide. The ratio of the fatty acid silver salt to the whole is preferably from 10 to 50% by mass, particularly preferably from 10 to 30% by mass. The addition of a metal ion selected from Ca, Mg, Ce, Al, Zn, and Ba is preferably performed in the form of a water-soluble salt that is not a halide. Specifically, it is preferable to add in the form of nitrate or sulfate. Ca, M of the present invention
g, Ce, Al, Zn, and Ba are added at the time of adding the metal ion in the solution or the reaction solution of the fatty acid silver salt preparation method of the present invention, during the formation of the fatty acid silver salt, immediately after the formation, and during coating. Any time may be used as long as it is just before the application, such as before and after the preparation of the liquid. The addition amount is preferably from 10 ^-3 to 10 ^-1 mol, particularly from 5 × 10 ^{-3 to} 5 per 1 mol of the fatty acid silver salt.
× 10 ^-2 mol is preferred.

The apparatus for carrying out the preparation method of the present invention is not particularly limited.
A first supply unit for supplying a silver ion-containing solution using water or a mixture of water and an organic solvent as a solvent to a closed mixing unit;
Second supply means for supplying a solution of a fatty acid alkali metal salt using water, an organic solvent, or a mixture of water and an organic solvent as a solvent to a closed mixing means; water or a mixture of water and an organic solvent to a closed mixing means; Third supply means for supplying; and a closed mixing means for mixing the supplies from the first supply means, the second supply means and the third supply means and discharging the liquid containing non-photosensitive fatty acid silver salt particles. An apparatus for preparing non-photosensitive fatty acid silver salt particles, which is characterized by having the same, is exemplified. This apparatus preferably further comprises a cooling means for cooling the liquid containing the non-photosensitive fatty acid silver salt particles discharged from the closed mixing means (FIG. 4).

Another preferred apparatus for carrying out the preparation method of the present invention is a first supply means for supplying a silver ion-containing solution using water or a mixture of water and an organic solvent to a closed mixing means. A second supply unit for supplying a solution of a fatty acid alkali metal salt using water, an organic solvent, or a mixture of water and an organic solvent as a solvent to a closed mixing unit; the first supply unit, the second supply unit, and a second supply unit; (3) Closed mixing means for mixing the supplies from the supply means to discharge the non-photosensitive fatty acid silver salt particle-containing liquid; and at least a part of the non-photosensitive fatty acid silver salt particle-containing liquid discharged from the closed mixing means And a third supply means for supplying the non-photosensitive fatty acid silver salt particles to the closed mixing means. The apparatus preferably further comprises a cooling means for cooling the liquid containing non-photosensitive fatty acid silver salt particles discharged from the closed mixing means (FIG. 2).

In the apparatus shown in FIG. 2, the non-photosensitive fatty acid silver salt particles having a desired concentration can be obtained by appropriately adjusting the amount of the non-photosensitive fatty acid silver salt particle-containing liquid supplied from the third supply means to the closed mixing means. Can be prepared in the tank 20. That is, since the concentration of the dispersion of the non-photosensitive fatty acid silver salt particles in the tank 20 is increased by repeating the circulation using the third supply means, the dispersion having the desired concentration can be obtained by appropriately selecting the circulation conditions. A liquid can be obtained. Further, the concentration can be adjusted by adjusting not only the circulation conditions but also the conditions for taking out the prepared dispersion liquid. By appropriately selecting these conditions, a desired dispersion can be efficiently obtained while performing continuous operation.

In the tank (20 in FIG. 2 and 40 in FIG. 4) for receiving the produced fatty acid silver dispersion, mixing means such as a stirrer, heat exchange means such as a jacket tank, and a liquid for uniformity of the contents are provided. A temperature measuring means, a level sensor for controlling the amount of liquid, and other means for measuring physical properties of liquid such as pH, conductivity, viscosity, etc., can be provided as needed.

The heat-developable image recording material which can use the non-photosensitive silver salt of a fatty acid prepared by the preparation method of the present invention will be further described. The heat-developable image recording material preferably has an image recording layer in which the above fatty acid silver salt as a reducible silver salt and a reducing agent for silver ions are dispersed in a binder matrix. To make it photosensitive, a catalytically active amount of a photocatalyst (preferably photosensitive silver halide) is further used. If necessary, a toning agent for controlling the tone of silver is used. Organic silver salts can be used in a desired amount, preferably 0.1-5 g / m ² as silver amount, more preferably from 1 to 3 g / m ^2.

The reducing agent for silver ions may be any substance (preferably an organic substance) that reduces silver ions to metallic silver. Such a reducing agent is disclosed in JP-A-11-6502.
No. 1, paragraph Nos. 0043 to 0045, and European Patent Publication No. 0803764A1, page 7, line 34 to page 18, page 1.
It is described in two lines. In the present invention, the addition amount of the reducing agent is preferably 0.01 to 5.0 g / m ² ,
The content is more preferably 0.1 to 3.0 g / m ² , and preferably 5 to 50 mol%, more preferably 10 to 40 mol%, per 1 mol of silver on the surface having the image forming layer. Is more preferable. The reducing agent is preferably contained in the image recording layer.

The photosensitive silver halide which can be used in the present invention is not particularly limited as a halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide can be used. Can be. The distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be changed continuously. Further, silver halide grains having a core / shell structure can be preferably used.

Methods for forming photosensitive silver halide are well known in the art and are described, for example, in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. Can be used. The addition amount of the photosensitive silver halide is
In terms of the amount of silver applied per m ^{2 of the} thermally developed image recording material,
It is preferably from 0.03 to 0.6 g / m ² ,
More preferably, it is from 0.05 to 0.4 g / m ² ,
Most preferably, it is 0.1 to 0.4 g / m ² .

The binder of the layer containing the organic silver salt may be any polymer, suitable binders being transparent or translucent, generally colorless, natural resins and polymers and copolymers, synthetic resins and polymers and copolymers, Other film-forming media such as gelatins, rubbers, poly (vinyl alcohol) s, hydroxyethyl celluloses, cellulose acetates, cellulose acetate butyrates, poly (vinyl pyrrolidone) s, casein, starch, poly (acrylic) Acids),
Poly (methyl methacrylic acid), Poly (vinyl chloride)
, Poly (methacrylic acid) s, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, poly (vinyl acetal) s (for example, poly (vinyl formal) and Poly (vinyl butyral)), poly (ester), poly (urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxide), poly (carbonate), poly (vinyl acetate), poly ( Olefin)
, Cellulose esters and poly (amides).
The binder may be coated from water or an organic solvent or emulsion. Preferably the total amount of the binder in the image-forming layer of the heat developable image recording material is 0.2 to 30 g / m ^2, more preferably 1 to 15 g / m ^2.

Other materials and structures applicable to the heat-developable image recording material are described in JP-A-10-62899, JP-A-10-268465, and JP-A-11-5.
2509, JP-A-11-352625, JP-A-11-352626, JP-A-11-3526
No. 27, Japanese Unexamined Patent Application Publication No. 11-349591, Japanese Unexamined Patent Application Publication No.
000-7683, JP-A-2000-72711, European Patent Publication No. 0803764A1, European Patent Publication No. 0962812A1, and the like can be referred to.

[0066]

The present invention will be described more specifically with reference to the following examples and test examples. Materials, reagents, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. The structural formula of the compound used in this example is as follows.

[0067]

Embedded image

<< Preparation of PET Support >> Using terephthalic acid and ethylene glycol, the intrinsic viscosity IV =
0.66 (phenol / tetrachloroethane = 6/4
(Measured at 25 ° C.) was obtained. This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, quenched, and heated to a film thickness of 1
An unstretched film having a thickness of 75 μm was prepared. This is longitudinally stretched 3.3 times at 110 ° C. using rolls having different peripheral speeds.
Then, transverse stretching was performed 4.5 times at 130 ° C. using a tenter. Thereafter, after heat-setting at 240 ° C. for 20 seconds, it was relaxed by 4% in the lateral direction at the same temperature. Subsequently, after slitting the biting portion of the tenter, knurling is performed on both ends to obtain a thickness 17.
A roll of 5 μm was obtained.

<< Surface Corona Treatment >> Both surfaces of the support were treated at room temperature at a rate of 20 m / min using a corona treatment machine (Piller's solid state 6KVA model). From the current and voltage readings at this time, 0.375
It was found that processing of KV · A · minute / m was performed.
The processing frequency at this time is 9.6 KHz, and the electrode and dielectric
The gap clearance of the shell was 1.6 mm.

<< Preparation of Undercoating Support >> (Preparation of Undercoating Coating Solution A) Aqueous dispersion of polyester copolymer
(30%, Takamatsu Yushi Peslesin A-515GB)
Polystyrene fine particles (average particle size 0.2μ
m) Add 1 g of surfactant A (1% by mass) 20 ml
Then, add distilled water to this to make 1000 ml,
The cloth liquid A was used. (Preparation of Undercoat Coating Solution B) Styrene in 680 ml of distilled water
-Butadiene copolymer aqueous dispersion (styrene / butadiene
/ Itaconic acid = 47/50/3 (mass ratio), concentration 30
%), Polystyrene fine particles (average particle size 2.
5 μm), and 0.1 g of distilled water was added.
The undercoating coating liquid B was set to 00 ml. (Preparation of Undercoat Coating Solution C) 10 g of inert gelatin was steamed.
Dissolved in 500 ml of distilled water,
No. 3 tin oxide-antimony oxide composite fine particles
40 g of an aqueous dispersion (40% by mass) of
Add distilled water to make 1000 ml and use it as undercoat coating solution C.
Was. (Preparation of undercoat support)
On the carrier, wet coat the undercoat coating solution A with a bar coater.
Cloth volume is 5ml / m^TwoApply at 180 ° C for 5 minutes
While drying. The film thickness after drying was about 0.3 μm. Next
Corona discharge treatment was applied to the back side (back side)
Thereafter, the amount of wet coating of the undercoat coating solution B with a bar coater is
5ml / m ^TwoAnd apply it so that the dry film thickness becomes about 0.3 μm.
And dried at 180 ° C for 5 minutes
Liquid C was applied with a bar coater at a wet application amount of 3 ml / m.^Two,
180 ° C after applying so that the dry film thickness becomes about 0.03μm
For 5 minutes to produce a subbed support.

<< Preparation of Fatty Acid Silver Salt Particle Dispersion A >> Behenic acid (manufactured by Henkel, product name: Edenor C22-85)
R) 876 g, distilled water (4,230 ml) and tert-butanol (1,200 ml) were stirred at 75 ° C. while 5N-N
After adding 492 ml of an aOH aqueous solution over 5 minutes, 60
After reacting for 1 minute, a sodium behenate solution was obtained. Separately,
2,062 ml of an aqueous solution (pH 4.0) of 404 g of silver nitrate was prepared and kept at 10 ° C. A reaction vessel containing 6,350 ml of distilled water and 300 ml of tert-butanol was kept at 30 ° C., and the whole amount of the silver nitrate aqueous solution was added at a constant flow rate over 60 minutes while stirring, and after 7 minutes, behen The entire amount of sodium acid solution was added at a constant flow rate over a period of 62 minutes (sodium behenate solution alone was added during the last 9 minutes). Leave to stir for 20 minutes, 25
The temperature was lowered to ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the permeated water became 30 μS / cm. The solid thus obtained was stored as a wet cake without drying.

To 560 g of the obtained wet cake of fatty acid silver (solid content: 40%) was added 424 g of distilled water having the following composition and polyvinyl alcohol (PVA-20 manufactured by Kuraray Co., Ltd.).
5) Add 22 g, and add 50 g using a homodisper (TK homodisper 2M-5, manufactured by Tokushu Kika Kogyo KK).
The mixture was treated at 00 rpm for 15 minutes to prepare a crude dispersion.
The obtained particles had an average particle size of 5.36 μm. The obtained coarse dispersion is applied to a microfluidizer (M110S-
Using an EH type, using a G10Z interaction chamber manufactured by Mizuho Industry Co., Ltd.), the mixture was once dispersed at a pressure of 1600 kg / cm ² to obtain a fatty acid silver salt dispersion A. At this time, the temperature was controlled so that the inlet temperature immediately before dispersion and the outlet temperature immediately after dispersion were 5 ° C. and 30 ° C., respectively.

<< Preparation of Dispersion B of Fatty Acid Silver Salt Particles >> A dispersion B was prepared using a small crystallization apparatus as shown in FIG.
In the tank 32, behenic acid (manufactured by Henkel, product name Ed)
enog C22-85R) 876 g, distilled water 4,230
While stirring 1,200 ml of tert-butanol at 75 ° C., 492 ml of 5N-NaOH aqueous solution was added over 5 minutes, and the mixture was reacted for 60 minutes to obtain a sodium behenate solution. Further, silver nitrate 404 is stored in the tank 31.
g of an aqueous solution (pH 4.0) of 2,062 ml was prepared.
It was kept at ° C. A closed mixer (Pipeline mixer LR-I type manufactured by Mizuho Industry Co., Ltd.) 38 was used at 10,000 rpm.
(Linear velocity at blade tip 4.2m / sec, stirring power 5.5kW /
While stirring in L), the above aqueous solution of silver nitrate was added at a constant flow rate of 29 ml / min, and after 5 seconds, a sodium behenate solution was added at a constant flow rate of 98 ml / min. Stocked in tank 40. However, when the supply of the cooling water to the heat exchanger was stopped and the cooling water at 10 ° C. was supplied to the jacket of the tank 40 at 20 L / min,
The average temperature in the tank was 35 ° C. The mixture was allowed to stand with stirring for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was determined to have a conductivity of permeate of 3%.
Washed with water until it reached 0 μS / cm. The solid thus obtained was stored as a wet cake without drying. Thereafter, it was dispersed in the same manner as the fatty acid silver salt particle dispersion A to obtain a fatty acid silver salt particle dispersion B.

<< Preparation of Dispersion C of Fatty Acid Silver Salt Particles >> Dispersion C was prepared using a small crystallization apparatus as shown in FIG.
In the tank 32, behenic acid (manufactured by Henkel, product name Ed)
enog C22-85R) 876 g, distilled water 4,230
While stirring 1,200 ml of tert-butanol at 75 ° C., 492 ml of 5N-NaOH aqueous solution was added over 5 minutes, and the mixture was reacted for 60 minutes to obtain a sodium behenate solution. Further, silver nitrate 404 is stored in the tank 31.
g of an aqueous solution (pH 4.0) of 2,062 ml and 4,000 ml of pure water in a tank 41 were prepared and kept at 10 ° C.
While stirring the closed mixer (Pipeline mixer LR-I type manufactured by Mizuho Industry Co., Ltd.) 38 at 10,000 rpm, the above aqueous solution of silver nitrate was 29 ml / min, and pure water was 98 ml.
Per minute, and after 5 seconds, sodium behenate solution was added at a constant flow of 98 ml / min, and the solution was stored in the tank 40 via the heat exchanger 39. However, when the supply of the cooling water to the heat exchanger was stopped and the cooling water of 10 ° C. was supplied to the jacket of the tank 40 at 20 L / min, the average temperature in the tank was 30 ° C. The mixture was allowed to stand with stirring for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the permeated water became 30 μS / cm. The solid thus obtained was stored as a wet cake without drying. Thereafter, it was dispersed in the same manner as the fatty acid silver salt particle dispersion A to obtain a fatty acid silver salt particle dispersion C.

<< Preparation of Fatty Acid Silver Salt Particle Dispersion D >> A dispersion was prepared in the same manner as in the above-mentioned dispersion C. However, the tank 41 has 4v
6,000 ml of an ol-% tert-butanol aqueous solution was prepared and added at a constant flow rate of 98 ml / min.

<< Preparation of Dispersion E of Fatty Acid Silver Salt Particles >> A dispersion was prepared in the same manner as in the above-mentioned dispersion C. However, in the tank 41, a 1% by mass aqueous solution of polyvinyl alcohol (Kuraray Co., Ltd.
VA-205) Prepare 6,000 ml and prepare 98 ml /
Min at a constant flow rate.

<< Preparation of Dispersion F of Fatty Acid Silver Salt Particles >> Dispersion F was prepared using a small crystallization apparatus as shown in FIG.
Behenic acid (made by Henkel, product name Ed in the tank 12)
enog C22-85R) 876 g, distilled water 4,230
Then, while stirring 1,200 ml of tert-butanol at 75 ° C., 492 ml of 5N-NaOH aqueous solution was added over 5 minutes, and then reacted for 60 minutes to obtain a sodium behenate solution. Further, silver nitrate 404 is stored in the tank 11.
g of an aqueous solution (pH 4.0) of 2,062 ml was prepared.
It was kept at ° C. In addition, the tank 20 contains 6,000
Measure pure water of ml and 1,000m via pump 17
Circulated at a flow rate of 1 / min. 1 closed mixer (Pipeline mixer LR-I type manufactured by Mizuho Industry Co., Ltd.)
While stirring at 000 rpm, the silver nitrate aqueous solution was added at a constant flow rate of 29 ml / min, and after 5 seconds, a sodium behenate solution was added at a constant flow rate of 98 ml / min.
It was stocked in the tank 20 via the heat exchanger 19. Here, 10 ° C. is applied to the heat exchanger and the jacket of the tank 20.
Was supplied at a rate of 20 L / min, and the average temperature in the tank was 30 ° C. The mixture was allowed to stand with stirring for 20 minutes, and the temperature was lowered to 25 ° C. Then, the solid content was separated by suction filtration, and the conductivity of the solid content was 30 μS / cm.
And washed with water. The solid thus obtained was stored as a wet cake without drying. After that,
It was dispersed in the same manner as the fatty acid silver salt particle dispersion A to obtain a fatty acid silver salt particle dispersion F.

<< Preparation of Dispersion G of Fatty Acid Silver Salt Particles >> A dispersion was prepared in the same manner as in the above-mentioned dispersion B. However, 5 ° C
When the cooling water was passed through, the average temperature in the tank 40 was 30 ° C.

<< Preparation of Dispersion H of Fatty Acid Silver Salt Particles >> A dispersion was prepared in the same manner as in the above-mentioned dispersion F. However, 5 ° C
When the cooling water was passed through, the average temperature in the tank 20 was 25 ° C.

Table 1 summarizes the conditions for preparing the fatty acid silver salt particle dispersions A to H. The average particle diameter of the fatty acid silver salt particles of the obtained fatty acid silver salt particle dispersions A to H, the coefficient of variation thereof, the viscosity measured by a B-type viscometer, and the increase in filtration pressure (diameter 1.
Using a 5cm Paul Epocell Filter EC,
Table 2 shows the result of examining the difference between the final pressure and the initial pressure when 2 kg was filtered at 50 cc / min.

[0081]

[Table 1]

<< Preparation of 25% Dispersion of Reducing Agent >> 80 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and modified Poval MP manufactured by Kuraray Co., Ltd.
176 g of water was added to and mixed with 64 g of a 20% aqueous solution of 203 to form a slurry. Prepare 800 g of zirconia beads having an average diameter of 0.5 mm and put them in a vessel with the slurry
The mixture was dispersed for 5 hours with a dispersing machine (1 / 4G sand grinder mill: manufactured by Imex) to obtain a reducing agent dispersion. The reducing agent particles contained in the dispersion thus obtained had an average particle size of 0.72.
μm.

<< Preparation of 20% Dispersion of Mercapto Compound >> 64-mer of 3-mercapto-4-phenyl-5-heptyl-1,2,4-triazole and modified Poval MP2 manufactured by Kuraray Co., Ltd.
224 g of water was added to and mixed with 32 g of a 20% aqueous solution of 03 to form a slurry. 800 g of zirconia beads having an average diameter of 0.5 mm were prepared, placed in a vessel together with the slurry, and dispersed in a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 10 hours to obtain a mercapto dispersion. The particles of the mercapto compound contained in the dispersion thus obtained had an average particle size of 0.67 μm.

<< Preparation of 30% Dispersion of Organic Polyhalogen Compound >> 48 g of tribromomethylphenylsulfone and 3-
Tribromomethylsulfonyl-4-phenyl-5-tridecyl
224 g of water was added to 48 g of -1,2,4-triazole and 48 g of a 20% aqueous solution of modified Poval MP203 manufactured by Kuraray Co., Ltd. to form a slurry. 800 g of zirconia beads having an average diameter of 0.5 mm is prepared, put into a vessel together with the slurry, and is dispersed in a dispersion machine (（G sand grinder mill:
For 5 hours to obtain an organic polyhalogen compound dispersion. The average particle size of the polyhalogen compound particles contained in the dispersion thus obtained was 0.74 μm.

<< Preparation of methanol solution of phthalazine compound >> 26 g of 6-isopropylphthalazine was added to methanol 10
It was used by dissolving it in 0 ml.

<< Preparation of 20% Dispersion of Pigment >> CI Pigme
64 g of nt Blue 60 and 6.4 mol of Demol N manufactured by Kao Corporation
250 g of water was added to the g and mixed to obtain a slurry. Prepare 800g of zirconia beads with an average diameter of 0.5mm,
The slurry was placed in a vessel together with the slurry, and dispersed in a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 25 hours to obtain a pigment dispersion. The average particle size of the pigment particles contained in the dispersion thus obtained was 0.21 μm.

<< Preparation of Silver Halide Grain 1 >> Distilled Water 14
6.7 ml of a 1% by weight potassium bromide solution was added to 21 ml, 8.2 ml of 1N nitric acid was added, and phthalated gelatin 2 was added.
While stirring the solution to which 1.8 g was added in a titanium-coated stainless steel reaction bottle, the solution temperature was maintained at 35 ° C., and a solution a1 prepared by adding distilled water to 37.04 g of silver nitrate to 159 ml and diluting potassium bromide to 32.04 g was added. 6 g in distilled water with a capacity of 200
The solution b1 was prepared by diluting the solution b1 to a volume of 0.1 ml and maintaining the pAg at 8.1 by the control double jet method.
Was added at a constant flow rate over 1 minute (solution b1
Is added by the controlled double jet method). Thereafter, 30 ml of a 3.5% aqueous hydrogen peroxide solution was added, and further 336 ml of a 3% by mass aqueous solution of benzimidazole was added. After that, the solution a1 is diluted again with distilled water and 31
Dipotassium hexachloride iridate is dissolved in 7.5 ml of the solution a2 and the solution b1 so that the final concentration becomes 1 × 10 ^-4 mole per 1 mole of silver, and the solution volume is twice that of the solution b1.
Using the solution b2 diluted with distilled water to 00 ml, the whole amount of the solution a2 was added at a constant flow rate over 10 minutes by a controlled double jet method while maintaining the pAg at 8.1 (solution b2 was controlled. Double jet method). Thereafter, 50 ml of a 0.5% methanol solution of 2-mercapto-5-methylbenzimidazole was added, the pAg was further raised to 7.5 with silver nitrate, the pH was adjusted to 3.8 with 1N sulfuric acid, and the mixture was stirred. Was stopped, a sedimentation / desalting / water washing step was performed, 3.5 g of deionized gelatin was added, 1N sodium hydroxide was added, and pH 6.0, pA
g was adjusted to 8.2 to prepare a silver halide salt particle dispersion.

The grains in the completed silver halide emulsion were pure silver bromide grains having an average equivalent spherical diameter of 0.031 μm and a variation coefficient of the equivalent spherical diameter of 11%. The particle size and the like were determined from the average of 1000 particles using an electron microscope. The {100} plane ratio of the particles was determined to be 8 using the Kubelka-Munk method.
It was determined to be 5%. The emulsion was heated to 50 ° C. while stirring, and 5 ml of a 0.5% by mass methanol solution of N, N′-dihydroxy-N ″, N ″ -diethylmelamine and a 3.5% by mass methanol solution of phenoxyethanol were added. Add 5 ml,
One minute later, 3 × 10 ⁻⁵ mol of sodium benzenethiosulfonate was added to 1 mol of silver. After a further 2 minutes, a solid dispersion (aqueous gelatin solution) of spectral sensitizing dye 1 was added at 5 × 10 ⁻³ mol per mol of silver, and after a further 2 minutes, a tellurium compound was added at 5 × 10 ⁻⁵ mol per mol of silver. And aged for 50 minutes. Immediately before the completion of ripening, 1 × 10 ⁻³ mol of 2-mercapto-5-methylbenzimidazole was added per 1 mol of silver to lower the temperature, and the chemical sensitization was terminated to prepare silver halide grains 1.

<< Preparation of silver halide grains 2 >> 700 m of water
1 g of phthalated gelatin 22 g and potassium bromide 30 m
After dissolving g, adjusting the pH to 5.0 at a temperature of 35 ° C., containing 159 ml of an aqueous solution containing 18.6 g of silver nitrate and 0.9 g of ammonium nitrate and potassium bromide and potassium iodide in a molar ratio of 92: 8. The aqueous solution was added over 10 minutes by the control double jet method while maintaining the pAg at 7.7. Then, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and 2 g of ammonium nitrate, and an aqueous solution containing 1 × 10 ^-5 mol of dipotassium hexachloride iridate and 1 mol of potassium bromide in 1 liter of pAg 7.7 were added.
After adding over a period of 30 minutes by the control double jet method while maintaining the pressure, 4-hydroxy-6-methyl-1,3,3a, 7-
1 g of tetrazaindene was added, and the pH was further lowered to cause coagulation and sedimentation for desalination. Thereafter, 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and the pAg to 8.2, and silver iodobromide grains (iodine content core: 8 mol%, average: 2 mol%, average size: 0.05 μm, projection area variation coefficient: 8%) ,
The preparation of {cubic particles having a {100} face ratio of 88%) was completed. The silver halide grains thus obtained were heated to 60 ° C., and 85 μmol of sodium thiosulfate and 2,3,4,
1.1 × 10 ⁻⁵ mol, 1.5 × 10 ⁻⁵ mol of tellurium compound, ⁵ , × 10 ⁻⁵ mol of 5,6-pentafluorophenyldiphenylphosphine selenide, 3.5 × 10 ⁻⁸ mol of chloroauric acid, 2. After adding 7 × 10 ^-4 mol and aging for 120 minutes, 4
After quenching to 0 ° C., 1 × 10 ^-4 mol of spectral sensitizing dye 1
And 5 × 10 ^-4 mol of 2-mercapto-5-methylbenzimidazole were added thereto, and the mixture was rapidly cooled to 30 ° C. to prepare a silver halide emulsion 2.
I got

<< Preparation of Emulsion Layer Coating Solution >> [Emulsion Layer Coating Solution No. 1] 103 g of the fatty acid silver salt particle dispersion obtained above and polyvinyl alcohol (Kuraray Co., Ltd.)
5% of a 20% by mass aqueous solution of PVA-205) was mixed and kept at 40 ° C., and the above 25% reducing agent dispersion 23.2 was added.
g, 5% aqueous dispersion of pigment CI Pigment Blue 60 is 4.8.
g, 10.7 g of a 30% dispersion of an organic polyhalide, and 3.1 g of a 20% dispersion of a mercapto compound. Thereafter, 106 g of UF-purified SBR latex kept at 40 ° C. was added in an amount of 106 g, and the mixture was stirred for a sufficient amount of time. After that, 6 ml of a methanol solution of a phthalazine compound was added to obtain a fatty acid silver-containing liquid. Also, 5 g of the silver halide grains 1 and 5 g of the silver halide grains 2 were mixed well in advance, and mixed and mixed with a fatty acid silver-containing liquid by a static mixer immediately before coating, and the coated silver amount was directly applied to a coating die at 1.4 g / g. The solution was sent to obtain m ² .

The viscosity of the emulsion layer coating solution was measured with a viscometer (B-type viscometer manufactured by Tokyo Keiki Co., Ltd.).
a · s. Using an RFS Fluid Spectrometer manufactured by Rheometrics Far East Co., Ltd.
The viscosity of the coating solution measured at 5 ° C. was such that the shear rate was 0.1,
At 1, 10, 100, and 1000 [1 / sec], they were 1500, 220, 70, 40, and 20 mPa · s, respectively.

The UF-purified SBR latex is
SBR latex (polymerization ratio of -St (68) -Bu (29) -AA (3)-)
Is diluted 10 times with distilled water, and UF purification module FS
03-FC-FUY03A1 (Daisen Membrane
1.5mS / c using System Co., Ltd.
It was obtained by diluting and purifying to m. At this time, the latex concentration was 40%. The physical properties of the latex solution thus prepared were such that the average particle size was 0.1 at a concentration of 45%.
μm, electrical conductivity was 4.2 mS / cm, and pH was 8.2.

<< Preparation of Emulsion Surface Intermediate Layer Coating Solution >> [Intermediate Layer Coating Solution] Polyvinyl alcohol (Kuraray Co., Ltd.)
772 g of a 10% by mass aqueous solution of PVA-205), a methyl methacrylate / styrene / 2-ethylhexyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer weight ratio 59/9/26/5/1) latex 27. 2 m of a 5% aqueous solution of aerosol OT (manufactured by American Cyanamid) was added to 226 g of a 5% liquid.
1, benzyl alcohol 4 g, 2,2,4-trimethyl-1,3-
1 g of pentanediol monoisobutyrate and 10 mg of benzicithiazolinone were added to prepare a coating solution for the intermediate layer.
The solution was fed to the coating die so as to be 1 / m ² . The viscosity of this intermediate layer coating solution is 21 mP at 40 ° C. with a B-type viscometer.
a · s.

<< Preparation of Coating Solution for Emulsion Surface Protective Layer First Layer >> [Protective Layer First Layer Coating Solution No. 1] Inert Gelatin 80
g of phthalic acid in water and 1% methanol solution of phthalic acid in 1
38 ml, 28 ml of 1N sulfuric acid, aerosol OT
(American Cyanamid Co.) 5% by weight aqueous solution
ml, 1 g of phenoxyethanol and a total amount of 1000
g of water to make a coating solution, 10 ml / m ²
To the coating die. The viscosity of the coating liquid for the protective layer was 17 mPa · s at 40 ° C. using a B-type viscometer.

<< Preparation of Emulsion Surface Protective Layer Second Layer Coating Solution >> [Protective Layer Second Layer Coating Solution] Inert gelatin (100 g) was dissolved in water, and N-perfluorooctylsulfonyl-N-
20 ml of a 5% solution of potassium propylalanine salt, 16 ml of a 5% by mass solution of aerosol OT (manufactured by American Cyanamid Co.), 25 g of polymethyl methacrylate fine particles (average particle size 4.0 μm), 44 ml of 1N sulfuric acid,
Water was added to 10 mg of benzicithiazolinone to a total amount of 1555 g, and 445 ml of an aqueous solution containing 4% by mass of chromium alum and 0.67% by mass of phthalic acid was added.
Was mixed and mixed by a static mixer immediately before application, and was directly sent to a coating die at 10 ml / m ² . The viscosity of this protective layer coating solution was 9
mPa · s.

<< Preparation of Back Surface Coating Liquid >> [Preparation of Solid Dispersion of Base Precursor] 64 g of a base precursor compound and a surfactant (manufactured by Kao Corporation)
Demol) was mixed with 246 ml of distilled water, and the mixed solution was dispersed in beads using a sand mill (1/4 Gallon sand grinder mill, manufactured by AIMEX Co., Ltd.) to give a base precursor solid dispersion having an average particle diameter of 0.2 μm. I got [Preparation of solid dye dispersion] 9.6 g of cyanine dye compound
And sodium p-alkylbenzenesulfonate 5.
8 g was mixed with 305 ml of distilled water, and the mixed solution was dispersed in beads using a sand mill (1/4 Gallon sand grinder mill, manufactured by Amimex Co., Ltd.) to obtain a dye solid dispersion having an average particle diameter of 0.2 μm. .

[Preparation of coating solution for antihalation layer] 17 g of gelatin, 9.6 g of polyacrylamide, 70 g of a solid dispersion of the above base precursor, 56 g of a solid dispersion of the above dye, and polymethyl methacrylate particles (average particle size 6.5 μm) 1.5 g, sodium polyethylenesulfonate 2.2 g, 0.2 g of a 1% aqueous solution of a blue coloring dye compound,
844 ml of water was mixed to prepare an antihalation layer coating solution.

[Preparation of Coating Solution for Protective Layer] The container was kept warm at 40 ° C., and 50 g of gelatin, 0.2 g of sodium polystyrene sulfonate, 2.4 g of N, N′-ethylenebis (vinylsulfone acetamide), t-octylphenoxy were used. Sodium ethoxyethanesulfonate 1 g, benzoisothiazolinone 30 mg, C ₈ F ₁₇ SO ₃ K 32 mg, C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ )
(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₄ -SO ₃ Na 64 mg, pure water 950 ml
This was mixed to form a protective layer coating solution.

<< Preparation of Photothermographic Materials A to H >> The above-mentioned undercoated support was coated with the antihalation layer coating solution at a solid content of solid dye of 0.04 g / m ² and the protective layer coating solution at gelatin. Simultaneous multilayer coating so that the amount becomes 1 g / m ² ,
After drying to form an antihalation back layer, the emulsion layer, the intermediate layer, the protective layer first layer, and the protective layer second layer are simultaneously coated in order from the bottom on the opposite side by using a slide hopper coating method. Then, a sample of the photothermographic material was prepared.

The coating speed was 100 m / min, the distance between the tip of the coating die and the support was 0.18 mm, and the pressure in the decompression chamber was set 392 Pa lower than the atmospheric pressure. In the subsequent chilling zone, a dry-bulb temperature of 18 ° C. and a wet-bulb temperature of 12 ° C. were blown at an average wind speed of 7 m / sec for 30 seconds to cool the coating solution, and then in a drying zone of a sloppy flotation system, A dry air having a dry-bulb temperature of 30 ° C. and a wet-bulb temperature of 18 ° C. is blown out of the slit hole at an air velocity of 20 m / sec.
Sprayed for 0 seconds to dry.

<< Evaluation of Photographic Performance >> After exposing the photosensitive materials A to H at an inclination of 8 degrees with respect to the normal line using a Kr laser sensitometer of 647 nm (maximum output: 500 mW), the exposure was performed at 120 ° C.
After processing for 2 seconds (heat development), the obtained image was measured with a densitometer. The results of the measurement were evaluated in terms of Dmin and sensitivity (the reciprocal of the ratio of the amount of exposure that gives a density higher than Dmin by 1.0). Regarding the sensitivity and Dmin, the characteristic of the photosensitive material A is 1
It is shown as a relative value when 00 is set. High sensitivity, Dmi
It can be said that the lower the value of n, the higher the drawing power of the photosensitive material.

<< Evaluation of Forced Storage Property >>
It was cut into 0.5 cm × 25.4 cm, and the squares were cut off by 0.5 cm and left for 1 day at 25 ° C./50% RH. Thereafter, 10 photosensitive materials were each sealed in a bag made of a moisture-proof material, and left in a refrigerator at 50 ° C. and a refrigerator at 4 ° C. for 5 days. Processing from exposure to heat development is performed in the same manner as in the evaluation of photographic properties, and the density of the unexposed portion
Was treated as a fog value. The fog increase rate was calculated according to the following equation. The lower the fog increase rate, the better the storage stability with time. Fog increase rate = [{Fog of high temperature storage sample)-(Fog of low temperature storage sample)] / {Maximum concentration of low temperature storage sample}-
(Fog of the sample stored at low temperature)]] × 100 The evaluation results are shown in the following table.

[0103]

[Table 2]

<< Comparison with the Prior Art >> Compared with the dispersion A of the prior art in which the reaction liquid is added to the open tank and stirred and mixed, the dispersion of the present invention in which the reaction liquid is added to the closed tank and stirred and mixed is added. In the objects B to H, the average particle diameter is generally small. Although not wishing to be bound by any theory, it is considered that this is because bubbles are not involved in the liquid and low-temperature charging becomes possible. Also,
According to the present invention, the atmosphere in which the reaction solution is added is strictly controlled, and more uniform particles can be formed. Therefore, excellent effects such as increased photographic activity and high sensitivity were obtained. This makes it possible to reduce the amount of the coated fatty acid silver, and to design a silver-saving prescription.

<< Effect of Third Component >> In the dispersions C to F, the third components other than silver nitrate and sodium behenate solution were changed. By adding the third component at a low temperature, the average particle diameter can be reduced, and the filtration pressure increase and the fog increase rate can be further improved.

<< Effect of Heat Exchanger >> In the dispersions G and H, 5 ° C. was applied to the heat exchanger in order to further lower the temperature immediately after mixing the reaction liquid.
Of cold water was supplied. As a result, the average particle diameter was further reduced, and the increase in filtration pressure and the fog increase rate were improved.

[0107]

The dispersion of non-photosensitive fatty acid silver salt particles prepared by the method of the present invention has excellent dispersion stability and coating suitability. The photothermographic material produced using the dispersion has a high antifogging property even after storage, and furthermore,
It has excellent image stability and light transmittance after heat development.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a method for preparing non-photosensitive fatty acid silver salt particles according to the present invention.

FIG. 2 is a schematic view showing one configuration example of an apparatus used for preparing non-photosensitive fatty acid silver salt particles according to the present invention.

FIG. 3 is a schematic view showing another configuration example of an apparatus used for preparing non-photosensitive fatty acid silver salt particles according to the present invention.

FIG. 4 is a schematic view showing still another configuration example of an apparatus used for preparing non-photosensitive fatty acid silver salt particles according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed type mixer 2 Heat exchanger A Additional component 1 B Additional component 2 C Additional component 3 D Product liquid (before heat exchange) E Product liquid (after heat exchange) 11,21,31 Tank for additional component 1 12,22 , 32 Tank for additive component 2, 13, 23, 23 ', 33 Flow meter for additive component 1, 14, 24, 24', 34 Flow meter for additive component 2, 15, 25, 25 ', 35 Pump for additive component 1, 16, 26, 26 ', 36 Pump for added component 2 17, 27, 27' Pump for circulating product liquid 18, 28, 28 ', 38 Hermetic mixer 19, 29, 39 Heat exchanger 20, 30, 40 For product liquid Tank 37 Pump for additional component 3 41 Tank for additional component 3 42 Flow meter for additional component 2

Claims (12)

[Claims] 1. A reaction between a silver ion-containing solution using water or a mixture of water and an organic solvent as a solvent, and a fatty acid alkali metal salt solution using water, an organic solvent, or a mixture of water and an organic solvent as a solvent. A method of preparing fatty acid silver particles by mixing and reacting the silver ion-containing solution and the fatty acid alkali metal salt solution in a closed mixing means. Method. 2. The method for preparing non-photosensitive fatty acid silver salt particles according to claim 1, wherein water or a mixture of water and an organic solvent is further added to the closed mixing means. 3. The method for preparing non-photosensitive fatty acid silver salt particles according to claim 2, wherein the water or a mixture of water and an organic solvent contains a dispersant. 4. The method for preparing non-photosensitive fatty acid silver salt particles according to claim 1, wherein at least a part of the mixture obtained after the reaction is circulated and added to the closed mixing means. 5. The method for preparing non-photosensitive fatty acid silver salt particles according to claim 1, wherein the mixture obtained after the reaction is cooled. 6. A first supply means for supplying a silver ion-containing solution containing water or a mixture of water and an organic solvent to a closed mixing means; water, an organic solvent, or a mixture of water and an organic solvent as a solvent. A second supply means for supplying a solution of the fatty acid alkali metal salt to the closed mixing means; a third supply means for supplying water or a mixture of water and an organic solvent to the closed mixing means;
And a closed mixing means for mixing the supplies from the first supply means, the second supply means and the third supply means and discharging a liquid containing non-photosensitive fatty acid silver salt particles. An apparatus for preparing photosensitive fatty acid silver salt particles. 7. The preparation of the non-photosensitive fatty acid silver salt particles according to claim 6, further comprising a cooling means for cooling the liquid containing the non-photosensitive fatty acid silver salt particles discharged from the closed mixing means. apparatus. 8. A first supply means for supplying a silver ion-containing solution containing water or a mixture of water and an organic solvent to a closed mixing means; water, an organic solvent, or a mixture of water and an organic solvent as a solvent. Second supply means for supplying a solution of the fatty acid alkali metal salt to be used to the closed mixing means; non-photosensitive fatty acid silver by mixing the supplies from the first supply means, the second supply means and the third supply means Closed mixing means for discharging the salt particle-containing liquid; and third supply means for supplying at least a part of the non-photosensitive fatty acid silver salt particle-containing liquid discharged from the closed mixing means to the closed mixing means. An apparatus for preparing non-photosensitive fatty acid silver salt particles. 9. The preparation of non-photosensitive fatty acid silver salt particles according to claim 8, further comprising a cooling means for cooling the liquid containing non-photosensitive fatty acid silver salt particles discharged from the closed mixing means. apparatus. 10. The apparatus according to claim 6, wherein said closed mixing means is a mixing apparatus having rotating blades in a closed vessel.
10. The apparatus for preparing non-photosensitive fatty acid silver salt particles according to any one of items 9. 11. The apparatus for preparing non-photosensitive fatty acid silver salt particles according to claim 10, wherein a linear velocity at an outermost peripheral portion of the rotor is 1 to 50 m / sec. 12. The stirring power for 1 liter of the mixed liquid in the mixing apparatus having the rotating blades is 0.1 to 10 k.
The apparatus for preparing non-photosensitive fatty acid silver salt particles according to claim 10, wherein W is W.