JPS5945130B2 - Method for producing silver halide photographic emulsion - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing a silver halide photographic emulsion.

More specifically, the present invention relates to a method for producing a silver halide photographic emulsion that provides excellent stability and photographic performance, and particularly for lithium-type photographic emulsions, that provides excellent halftone dot quality while shortening the optimum development time. The method for producing silver halide photographic emulsions is usually a double decomposition reaction between a water-soluble silver salt and a water-soluble halide in a hydrophilic colloid such as an aqueous gelatin solution, thereby dispersing silver halide crystals in the hydrophilic colloid. The process involves lowering the temperature to complete physical ripening, and then removing excess salts, which are by-products of the metathesis reaction.

One method for removing excess salts is the flocculation method, in which silver halide grains are coagulated and precipitated together with hydrophilic colloids by adding a flocculant to the emulsion that has undergone physical ripening, and separated from the mother liquor containing salts. It has been known. The flocculation method is now widely used because it has advantages such as better efficiency than the noodle method, which is known as another method for removing salts. However, according to this flocculation method, the method of adding a flocculant to the emulsion that has undergone physical ripening is complicated and requires considerable skill, as well as the disadvantage that it requires a long preparation time. was seen.

Furthermore, when preparing emulsions continuously, it is necessary to add the flocculation and sedimentation agent by precisely proportional measurement, and the basis weight accuracy of this sedimentation agent may be insufficient, or various conditions such as temperature conditions at the time of addition may occur. If it is inappropriate, the formation and size of emulsion blocks may become non-uniform, or the resulting emulsion may have poor redispersibility, which may impede subsequent steps. Furthermore, silver halide was suspended in the supernatant of the mother liquor containing salts, reducing the yield, or depending on the type of flocculation and sedimentation agent used, had an adverse effect on photographic performance. Techniques to solve these drawbacks include, for example, Japanese Patent Publication No. 13057/1983 and Japanese Patent Publication No. 50-10/1983.
A method described in Publication No. 157 and the like has been proposed.

The former method is an invention in which a flocculation-sedimenting agent is added to a gelatin-containing solution before the end of physical ripening, and has a certain degree of effectiveness in improving the redispersibility and yield of the resulting emulsion and simplifying the basis weight of the sedimentation agent. It is proving effective. On the other hand, the latter method is an invention that employs a centrifugal separation method, and is effective in saving washing water and shortening the process. However, even with these inventions, stability and photographic performance are not necessarily sufficient, and it cannot be said that all of the above-mentioned problems have been solved.

The present invention was made in order to solve the above-mentioned problems, and it is possible to stably and reliably obtain an emulsion with excellent photographic performance, and to stably maintain excellent photographic performance over a long period of time. The first object is to provide a method for producing a silver halide photographic emulsion that can be maintained.

A second object of the present invention is to provide a method for terminating physical ripening,
It is an object of the present invention to provide a method for producing a silver halide photographic emulsion, which requires less than half the cooling time of conventional methods and can significantly shorten the preparation time of the emulsion.

A third object of the present invention is that the emulsion obtained after decantation can be easily redispersed, there is no risk of interfering with subsequent steps, and the emulsion can be stirred and mixed for a short time.
An object of the present invention is to provide a method for producing a silver halide photographic emulsion, which can produce an emulsion of stable quality.

A fourth object of the present invention is that photographic performance is not adversely affected by the type of flocculation-sedimenting agent used or the precision of its basis weight, and a wide variety of sedimentation agents can be used. An object of the present invention is to provide a method for producing a silver halide photographic emulsion that can make maximum use of the characteristics of the process.

A fifth object of the present invention is to be able to improve the yield of the emulsion prepared by one or two orders of magnitude compared to the conventional method. There is about 1% of silver halide that is not converted to , but it is an object of the present invention to provide a method for producing a silver halide photographic emulsion that can suppress this to about 0.01 to 0.1%.

A sixth object of the present invention is to provide a halogen-based emulsion that does not deteriorate the physical properties of hydrophilic colloids such as gelatin, thereby providing high stability of the emulsion over time, and having extremely good coating properties on supports such as films. An object of the present invention is to provide a method for producing a silver oxide photographic emulsion.

A seventh object of the present invention is to improve photographic performance, especially a method for producing a silver halide photographic emulsion that can significantly reduce fog by increasing the rate of temperature reduction during cooling to complete physical ripening. The goal is to provide the following.

An eighth object of the present invention is to provide a silver halide photographic emulsion that, when used in a silver halide photographic light-sensitive material for phosphor rays, accelerates development with a Lith-type developer (contagious developer) while maintaining ultra-high contrast. An object of the present invention is to provide a manufacturing method.

The ninth object of the present invention is to obtain a silver halide containing silver chloride or silver bromide as a main component.
It is an object of the present invention to provide a method for producing a silver halide photographic emulsion that can be sensitized by 100%.

A tenth object of the present invention is to obtain a silver halide containing 75 mol% or more of silver chloride, thereby making it possible to narrow the grain distribution. For example, when used in a lithium-type silver halide photographic material, The so-called Black-Pepp
An object of the present invention is to provide a method for producing a silver halide photographic emulsion that can suppress the occurrence of ercOne). An eleventh object of the present invention is to be able to improve high illuminance characteristics,
The object of the present invention is to provide a method for producing a silver halide photographic emulsion that can be suitably used, for example, in a silver halide photographic light-sensitive material for flash exposure.

The above object and other objects of the present invention described below are to mix a water-soluble silver salt and a water-soluble halide in the presence of a hydrophilic colloid to form silver halide crystals dispersed in the hydrophilic colloid. , the physical ripening is completed by lowering the temperature within 1 minute per 1.5°C on average, and at or after the completion of the physical ripening, the silver halide crystals are coagulated and precipitated in the presence of a coagulating sedimentation agent. , is achieved by removing the by-product salt produced by the metathesis reaction between the water-soluble silver salt and the water-soluble halide. In carrying out the method of the present invention, water-soluble silver salts such as an aqueous solution of silver nitrate, and water-soluble halides such as aqueous solutions of potassium bromide, potassium iodide, potassium chloride, and sodium chloride,
By mixing in the presence of a hydrophilic colloid such as a gelatin-containing solution, silver bromide, silver iodide, silver chloride,
Silver halide crystals such as silver iodobromide, silver chlorobromide, silver chloroiodide, silver chloroiodobromide, etc. are produced in a dispersed manner. Next, to terminate the physical ripening, the temperature is lowered using an appropriate method within 1 minute per 1.5° C. on average to terminate the physical ripening. Thereafter, an appropriate coagulation-sedimenting agent and the above-mentioned emulsion that has undergone physical ripening are mixed to coagulate and precipitate silver halide crystals produced by a metathesis reaction between a water-soluble silver salt and a water-soluble halide. Excess salt present in the solution is removed by decanting or the like. In addition, when mixing with the coagulation-sedimentation agent, the emulsion that has undergone physical ripening is adjusted to a temperature and pH range such that the coagulation-sedimentation effect occurs. After desalting the emulsion which has been subjected to physical ripening under certain conditions as described above, the emulsion is further transferred to a process such as chemical ripening by the same method as the conventional method such as pH adjustment. One of the characteristics of the method of the present invention is the method of terminating the physical ripening.

That is, the physical ripening is completed by lowering the temperature within 1 minute per 1.5° C. on average. Conventionally, physical ripening has been terminated by gradually lowering the temperature, but when physical ripening is terminated by lowering the temperature with a specific temperature gradient as in the method of the present invention, the above-mentioned results can be obtained. The fact that a silver halide photographic emulsion with excellent properties could be obtained was a surprising result that could not have been predicted from the knowledge of the prior art. The means for completing the physical ripening in the method of the present invention is to form silver halide crystals dispersed in a hydrophilic colloid as described above, and to lower the temperature of the emulsion within 1 minute per 1.5°C on average. Any method that can satisfy the requirements can be adopted.

For example, placing a cooling device on the inner or outer wall of a container in which the emulsion is physically ripened or another container into which the emulsion is transferred; circulating a cooling medium; flowing or circulating a cooling medium along the outer wall of any of the above containers; adding a cooling medium into any of the above containers; Adding a cooling medium containing a coagulation-sedimentation agent, transferring the emulsion in a container for physical ripening of the emulsion to another container having a pre-adjusted cooling temperature, and performing physical ripening. The emulsion in the container is passed through an emulsion transfer part (for example, a heat dissipation or cooling pipe) made of a thermally conductive material to radiate or cool the emulsion, and a method of cooling is performed by a combination of two or more of the above methods. be able to. The conditions for completing the physical ripening in the present invention are as described above, an average of 1.5
The temperature of the emulsion should be lowered within 1 minute per °C, but this condition requires a large temperature difference, for example, 1.8 °C or more per minute, or even 2.0 °C per minute. , is desirable for achieving the above-mentioned objects of the present invention, particularly improving emulsion yield and emulsion sensitizing effect.

The method of the present invention is characterized by lowering the temperature of the emulsion under the above-mentioned conditions, but as long as various conditions are met, it is also possible to use a flocculation-sedimentation agent to complete the physical ripening. For example, it is possible to cool a container in which the emulsion is physically ripened by refluxing a cooling medium and to add a cooling medium containing a coagulation-sedimenting agent to the emulsion in the container. Another feature of the method of the present invention is that a flocculation and sedimentation agent for desalting is added to the emulsion at the end of physical ripening or after completion of physical ripening.

Any flocculant-sedimenting agent can be used in the present invention. For example, organic solvents described in British Patent No. 819039, etc., US Patent No. 30077
96 specification, French Patent No. 1333773, US Patent No. 2,618,556, casein compounds described in US Patent No. 3,144,355, US Patent No. 2,481,650, etc. No. 2719146, No. 2728662, No. 2768079, French Patent No. 1311549, compounds having binding properties with amino groups, and complexes with gelatin For example, anionic soaps described in US Pat. No. 2,489,341, US Pat. No. 2,527,261, etc., and US Pat.
Specification No. 72165, Japanese Patent Publication No. 48-13057,
Copolymers described in Publication No. 40-21020, British Patent No. 861984, etc., Japanese Patent Publication No. 40-27
Nitrogen-containing heterocycles described in Publication No. 470, Perky Patent No. 637343, etc., British Patent No. 945
Naphthalene compounds described in Japanese Patent Publication No. 334, Japanese Patent Publication No. 35-216086, etc., polyethylene sulfonic acids described in West German Patent No. 1146117, etc., phenols described in Japanese Patent Publication No. 43-27562, etc. Derivatives, phosphoric acid esters described in Perky Patent No. 642112, etc., JP-A-52-35624
Ethylene-based copolymers and the like described in Japanese Patent Publication No. 1, etc. can be preferably used. The method of the present invention is applicable to any emulsion manufacturing method, such as an ammonia method, a neutral method, or an acid method.

Further, in the method of the present invention, the water-soluble silver salt and the water-soluble halide may be mixed in the hydrophilic colloid by any of forward mixing, back mixing, and simultaneous mixing, and the conversion method or coating emulsion method may be used. (CO-Nveredgrain
) law etc. may be adopted. Conventional conditions can be applied to the physical ripening conditions of the present invention. That is, physical ripening conditions such as temperature, pH, silver ion concentration, time, stirring conditions, and type and concentration of hydrophilic colloid can be optimally selected depending on the type of silver halide photographic emulsion intended. In addition, iridium, rhodium, ruthenium, osmium,
It may also contain metal atoms such as cobalt, bismuth, and cadmium.

Furthermore, it may be a surface latent image type or an internal latent image type. The silver halide photographic emulsion according to the present invention thus prepared is chemically ripened by any known method.

That is, this silver halide photographic emulsion contains activated gelatin, a sulfur sensitizer such as allylthiocarbamide, thiourea, cystine, a selenium sensitizer, a noble metal sensitizer such as a gold sensitizer, ruthenium, rhodium, iridium, etc. Chemical sensitization can be carried out by using sensitizers such as these alone or in combination as appropriate. Furthermore, this silver halide photographic emulsion can be optically sensitized, for example, by cyanine dyes and merocyanine dyes.This silver halide photographic emulsion also contains triazoles, tetrazoles, imidazoles, and azaindenes. , quaternary benzothiazolium compounds, zinc or cadmium compounds, and may also contain sensitizing compounds such as quaternary ammonium salts or polyethylene glycol, and also suitable gelatin plasticizers, Various photographic additives such as gelatin hardeners, spreading agents such as saponins, and coating aids such as sulfosuccinates may also be included.

Furthermore, various additives commonly used in photography, such as antifoggants and ultraviolet absorbers, can also be included, if necessary.
In the present invention, gelatin is preferably used as the hydrophilic colloid as a dispersant for silver halide, but in addition to gelatin, various natural or synthetic colloidal substances such as gelatin derivatives and polyvinyl alcohol may be used alone or It can also be used in combination with gelatin.

The silver halide photographic emulsion obtained by the method of the present invention has good redispersibility and good coating properties, so it is suitable for obtaining various silver halide photographic materials by coating it on a suitable support such as a film. ing.

According to the method of the present invention, the cooling time to complete physical ripening is less than half that of the conventional method, so the emulsion preparation time can be greatly shortened. Since quantitative accuracy does not have an adverse effect on photographic performance, it is no longer necessary to precisely measure the flocculant and precipitant in proportion to the amount of hydrophilic colloids such as gelatin after physical ripening, especially during the continuous preparation of emulsions. It is possible to select a flocculation-sedimentation agent from among many types of sedimentation agents that suits the emulsion to be used and the characteristics of the process, and since the emulsion obtained is easy to re-disperse, there is no risk of interfering with the subsequent process. By stirring and mixing for a short time, it is possible to obtain an emulsion of stable quality, excellent stability over time, and excellent photographic performance.

In addition, since the separation between the coagulated and settled emulsion and the mother liquor is stable and reliable, the yield of the emulsion can be improved by one or two orders of magnitude compared to the conventional method, and the emulsion has extremely good coating properties. Therefore, it is suitable for obtaining various silver halide photographic materials by coating on a support such as a film. Furthermore, fog can be greatly reduced by increasing the rate of temperature reduction during cooling to complete physical ripening, and especially when obtaining a silver halide photographic emulsion for lithography, ultra-high contrast can be achieved. In the former case, by obtaining silver halide containing silver chloride or silver bromide as a main component in the method of the present invention, development can be accelerated with a Lith-type developer (infectious developer) while maintaining the properties.
0%, even in the latter case, 20% sensitization is possible, and 75
By obtaining silver halide containing silver chloride in an amount of mol % or more, the grain distribution can be narrowed, and the generation of black pins can be suppressed, especially when used in lithium-type silver halide photographic light-sensitive materials. Furthermore, since the high illuminance characteristics can be improved, great effects such as suitability for use in silver halide photographic light-sensitive materials for flash exposure can be obtained.
Since the silver halide photographic emulsion obtained by the method of the present invention has the above-mentioned characteristics, it can be used for various types of films such as graphic films, micro films, color negative films, color reversal films, X-ray films, direct positive films, and motion picture positive films. It can be used as an emulsion for silver halide photographic light-sensitive materials.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the embodiments of the present invention are not limited thereto.

Example 1 A silver halide photographic emulsion was prepared using Liquid I and liquids having the following compositions.

[Liquid I]

[H liquid] \'41 Go'zei'! 1 - VVVV▼VJυ In a reaction vessel, mix the above 1st liquid and the liquid at 65°C, hold at the same temperature for 3 minutes, and then pour 500ml of 9°C cold water into the obtained emulsion.
1 was added over a period of 2 minutes to complete the physical ripening.

The average temperature drop of the emulsion at this time was 13°C/min.
Thereafter, 120 ml of a 10% aqueous solution of a copolymer of potassium panvinylbenzenesulfonate and N-acryloylmorpholine was added to the obtained emulsion to coagulate and precipitate the emulsion.
The emulsion was fractionated by tilting.

This emulsion was chemically ripened at 50° C. for 40 minutes in the presence of chloroauric acid, rhodasoammonium and sodium thiosulfate, and 0.60 g of 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene 1 saponin 2. 0g1 mucochloric acid 0.
After adding 4 g to prepare a coating solution, it was coated on a polyester film support to obtain sample [A]. Obtained sample [A
] was exposed to tungsten light for 2 seconds through a wedge,
Phenidone-Hydroquinone Sakura Doll Type 6
11 (manufactured by Konishiroku Photo Industry Co., Ltd., Sakura Doll is a registered trademark) at 35° C. for 1 minute.

Example-2 Sample [B] was prepared in the same manner as in Example-1, but in this example, after mixing the I solution and H solution in Example-1 and holding it for 3 minutes, 500 ml of 40°C water was added. was added to the emulsion reaction vessel, and 9°C cold water was further circulated through the outer wall of the reaction vessel to complete the physical ripening.

The average temperature drop of the emulsion at this time was 2°C/min. The sample [B] thus obtained was exposed and developed in the same manner as in Example-1. Comparative Example-1 Sample [C] was prepared in the same manner as in Example-1, but in this comparative example, after mixing the I solution and H solution in Example-1 and holding for 3 minutes,
Physical ripening was completed by circulating water at 35°C through the outer wall of the emulsion reaction vessel.

The average temperature drop of the emulsion at this time was 0.63°C/min. The sample [C] thus obtained was exposed and developed in the same manner as in Example-1. Obtained sample [A],
The photographic performance of each of [B] and [C] was measured, and at the same time, the presence or absence of coating spots was examined. The results are shown in Table 1. As is clear from Table 1, the method of the present invention is effective in suppressing the occurrence of fog and increasing sensitivity. In addition, samples [A] and [B] based on the method of the present invention
Example 3 A silver halide photographic emulsion was prepared using a liquid having the following composition, a liquid and a liquid V.

〔liquid〕

The solution and V solution were simultaneously kept at 60°C and allowed to flow down for 2 minutes into an emulsion reaction vessel in which the liquid was kept at 55°C. Cold water was circulated through the outer wall of the reaction vessel, and 100 ml of a 5% aqueous solution of sodium poly-β-naphtomethylene sulfonate was added over a period of 2 minutes, resulting in physical ripening with an average temperature drop of 2.0 °C/min. Finished it.

Thereafter, 25 ml of a 10% aqueous solution of magnesium sulfate was gradually added to the obtained emulsion to cause the emulsion to coagulate and settle, and the supernatant liquid was removed using a pump.

The remaining emulsion was processed at 55°C using gold sensitizer and sulfur sensitizer.
After chemical aging for 0 minutes, 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene 0.8g1 spirobis-3,3-dimethyl-5,6-dihydroxyindan 12W19, polyethylene glycol (molecular weight 15
40) and 5-[(3-γ-sulfopropyl-2-benzoxazonylidene)ethylidene]-1-(β-hydroxyethynol-3-phenylthiohydantoin 1007f1f) as a color sensitizer.
1. 0.5 g of bis-trimethylene-iminocarbonyl-ethyleneimine was added as a hardening agent to prepare a coating solution, which was then coated onto a polyester film support to obtain sample [D]. After exposing the obtained sample [D] to tungsten light for 2 seconds through a magenta contact screen and wedge,
Step development was performed at 27° C. for 1 to 2 minutes using Sakuradol Lithotype 211 (manufactured by Konishiroku Photo Industry Co., Ltd.), which is a lithium-type developer.

Example-4 Sample [E] was prepared in the same manner as in Example-3, but in this example, the average temperature drop until the end of physical ripening was 1.5°C.
The cooling water circulated through the outer wall of the reaction vessel was controlled so that the amount of water per minute was maintained.

The obtained sample [E] was exposed and developed in the same manner as in Example-3. Comparative Example-2 A sample was prepared in the same manner as in Example-3.
In this comparative example, Example-4 was prepared so that the average temperature drop until the end of physical ripening was 0.56°C/min.
The temperature of the outer wall of the reaction vessel was controlled in the same way.

For each of the obtained samples [D], [E] and [F], the sensitivity, optimum development time and halftone dot quality at a development time of 1 minute and 30 seconds were measured.

The results are shown in Table 2. As is clear from Table 2, according to the method of the present invention, lithographic development is promoted while maintaining ultra-high contrast.

Example 5 When preparing a chlorobromosilver iodide emulsion using the liquid, liquid and V liquid shown in Example 3, an apparatus consisting of a mixing tank (inner volume 650 m0) and a physical ripening tank (inner volume 21) was used. Using.

First, into a mixing tank containing 200 d of liquid, the liquid kept at 70°C and the V liquid were simultaneously allowed to flow down by 100 d for 15 seconds, immediately transferred to a physical aging tank, and kept at 60°C for 10 minutes.

Thereafter, 150 ml of the physical ripening tank was returned to the mixing tank, and the remaining amounts of liquid and V liquid (200 W 11 each) were allowed to flow down into this mixing tank, immediately transferred to the physical aging tank, and kept at 60° C. for 2 minutes. Next, the entire emulsion in this physical ripening tank was transferred to a stainless steel pipe (diameter 10 mu, length 1
．． 5 m), the average temperature drop of the emulsion was 11.25 C.
The physical ripening was completed at /min. Thereafter, 50T of a 5% aqueous solution of sodium poly-β-naphtomethylene sulfonate was added to the resulting emulsion. 11 was added to coagulate and settle the emulsion, and the emulsion was fractionated. This emulsion was chemically ripened and 4-hydroxy-
6-methyl-1,3,3a,7-tetrazaindene 1,
0 g, 0.5 g of diethylene glycol, 3-(β-hydroxyethyl)-5-[1-methyl-4(1H)-pyridylidene]-rhodanine 507n9, 0.3 g of sodium diethylhexyl succinate sulfonate, and 0.3 g of formalin. In addition, sample [G] was obtained by coating on a polyethylene terephthalate film support so that the coated silver amount was 45 d/100 d. The obtained sample [G] was wedge-exposed with a xenon single pulse through a magenta contact screen, and the former was In the latter case, development was carried out at 35°C for 1 minute, and in the latter case, step development was carried out at 27°C for 1 minute to 2 minutes and 30 seconds. Example-6 Sample [H] was prepared in the same manner as in Example-5 and developed in the same manner, but in this example, the emulsion was cooled so that the average temperature drop until the end of physical ripening was 5°C/min. The temperature of the pipe was controlled.

Comparative Example-3 Sample [] was prepared in the same manner as in Example-5 and developed in the same manner, but in this comparative example, the average temperature drop until the end of physical ripening of the emulsion was set to 0.68°C/min. The temperature of the cooling pipe was controlled.

The photographic performance of each of the obtained samples [G], [H], and [1] was measured, and the results are shown in Table 3.

As is clear from Table 3, according to the method of the present invention, the sensitivity to high-intensity short exposure is high and fog can be reduced, and in the case of lithographic development, it is found that it has the effect of promoting development by sensitizing with high gamma.

Claims (1)

[Claims] 1. A water-soluble silver salt and a water-soluble halide are mixed in the presence of a hydrophilic colloid to form silver halide crystals dispersed in the hydrophilic colloid, taking an average of less than 1 minute per 1.5°C. The physical ripening is completed by lowering the temperature, and at or after the completion of the physical ripening, the silver halide crystals are coagulated and precipitated in the presence of a coagulating precipitating agent, and the water-soluble silver salt and the water-soluble halide are metathesized. 1. A method for producing a silver halide photographic emulsion, which comprises removing a salt by-product produced by the reaction.