JPH04125634A - Production of silver halide photographic emulsion and photosensitive material - Google Patents

Abstract

PURPOSE:To eliminate dispersion faults by evaporating photographic additives in gas to form the fine particles thereof and adding these fine particles in the form of powder into the silver halide photographic emulsion or adding these particles therein after dispersing or mixing the particles into or with an aq. soln. or aq. protective colloid soln. CONSTITUTION:The photographic additives are evaporated in the gas and are made into the fine particles. Such fine particles are added in the form of the powder to the silver halide photographic emulsion or are added thereto after the fine particles are dispersed or mixed in or with the aq. soln. or aq. protective colloid soln. Namely, the photographic additives are evaporated by an in-gas evaporation method and are stuck in the form of the fine particles to the adherend. Such fine particles are scraped and collected, by which the superfine particles of the photographic additives are obtd. The time required for the adsorption onto the silver halide particles is shortened in this way and the generation of the coating troubles by the precipitation, etc., at the time of application of the emulsion is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a silver halide photographic emulsion, and particularly to a silver halide photographic emulsion containing a substantially water-insoluble photographic additive. Regarding addition to. The present invention further relates to a method for forming ultrafine particles of a water-insoluble photographic additive.

[Conventional technology]

Conventionally, when adding various water-insoluble photographic additives to a silver halide photographic emulsion, the photographic additive is dissolved in an organic solvent such as methanol, and the solution is added to a silver halide photographic emulsion. This method was generally widely used. However, since such a method uses an organic solvent, there are problems such as the formation of aggregates in the silver halide photographic emulsion, and the problem that it is difficult to coat the silver halide photographic emulsion. There were drawbacks such as lump-like or streak-like coating failures that sometimes occurred.

Instead of such conventional methods, when adding water-insoluble photographic additives to silver halide photographic emulsions, it is now possible to use organic solvents, wetting agents and dispersants, which were previously thought to be essential. For example, the following methods are known.

That is, in JP-A-58-105141, a substantially water-insoluble photographic additive is mechanically crushed and dispersed into fine particles of 1 μm or less in an aqueous system under conditions of pH 6 to 8.60 to 80°C. The dispersion is added to a silver halide photographic emulsion.

However, additional tests conducted by the present inventors have revealed that the viscosity of the dispersion liquid increases as the dispersion of the additive progresses, and air bubbles may be drawn in to impede the dispersion of the additive.

Furthermore, the method of adding powdered photographic additives to silver halide photographic emulsions has the problem of requiring a long time for adsorption to silver halide.

[Purpose of the invention]

The object of the present invention is to solve the above-mentioned problems, to obtain substantially water-insoluble ultrafine particles of a photographic additive, to provide a method for adding the ultrafine particles to a silver halide photographic emulsion, and to provide a method for producing a photographic material free from dispersion problems. On offer.

[Structure of the Invention] The above-mentioned objects of the present invention are: (1) A method for producing a silver halide photographic emulsion in which a substantially water-insoluble photographic additive is added to the silver halide photographic emulsion. A photographic additive is made into fine particles by evaporation in a gas, and the fine particles are added to a silver halide photographic emulsion in the form of a powder, or the fine particles are dispersed or mixed in an aqueous solution or a protective colloid aqueous solution. A method for producing a silver halide photographic emulsion characterized by: and (2)
A photosensitive material having at least one silver halide photographic emulsion layer on a support, wherein the silver halide photographic emulsion layer contains a silver halide photographic emulsion produced by the above production method. achieved by the material.

As a result of various studies, the inventors of the present invention first evaporated the photographic additive using an evaporation method in gas, made it into fine particles and attached it to the adherend, and collected the fine particles by scraping them off. Ultrafine particles of a photographic additive were obtained. In the present invention,
The ultrafine particles obtained as described above are dispersed in a powder state in a silver halide photographic emulsion, or the ultrafine particles are dispersed or mixed in an aqueous solution or a hydrophilic protective colloid, and the additive is added to the emulsion. Added. In this method, dispersed fine particles with a uniform particle size distribution and small particle size could be obtained in the emulsion without being hindered by the entrainment of air bubbles, unlike dispersion of photographic additives in an aqueous system.

To further explain the dispersion method in detail, among the ultrafine particles of the photographic additive obtained by the above method, additives that are difficult to form so-called "mamako" when added to a silver halide photographic emulsion due to their physical properties. It is also possible to add directly to a silver halide photographic emulsion in the form of ultrafine particles, that is, in the form of a powder. Further, a very small amount of an aqueous solution or a protective colloid solution may be added to the ultrafine particles to form a paste or suspension. Furthermore, the ultrafine particles may be pressurized to form tablets of a predetermined amount to make the addition operation more convenient.

Examples of devices that can be used in the present invention will be specifically explained below.

The in-gas evaporation method referred to in the present invention is the process of heating, evaporating, and evaporating various substances in an inert gas atmosphere introduced into a vacuum container.
In this method, the vapor molecules obtained through sublimation are gradually cooled and coagulated while colliding with inert gas molecules to form ultrafine particles.

Fig. 1 shows a vapor deposition apparatus for producing ultrafine particles according to the present invention.
In this example, the vaporizable material M is placed in the vacuum chamber 1.
A storage container 2, a rotating drum 3, and a collection box 4 are provided. The vacuum chamber l includes a supply pipe 5 for an inert gas G such as argon or helium, and an exhaust pipe 7 connected to a vacuum pump 6.
are in communication with each other, and a pressure gauge 8 is attached to the exhaust pipe 7 to detect the degree of vacuum. A rotating drum 3 on which ultrafine particles adhere and accumulate is located above the container 2. The collection box 4 is thermally isolated from the storage container 2 and the attachment portion of the evaporable material M to the rotating drum 3 by a heat shielding plate 9.

On the other hand, when the rotating direction of the rotary drum 3 is set to the counterclockwise direction in FIG. A collection box 4 is provided with an entrance facing below the scraping blade 1o.

The angle of scraping by the blade lθ at this time is preferably a reverse angle, but other angles such as trailing are also possible.

Furthermore, it is preferable that the storage container 2 for the evaporable material M is made of a heat-resistant material such as ceramic, and the storage container 2 and/or the directly evaporable material M can be heated by heater heating, induction heating, laser heating, or resistance heating. Alternatively, the material M is heated to a temperature at which the material M is sufficiently evaporated by heating with an electron gun or the like. Further, at this time, the rotating drum 3 is not only kept at the temperature within the vacuum chamber 1, but also preferably cooled, for example, to 10° C. or lower. This cooling can be achieved by passing a cooling heat medium, such as cooling water, through the rotating drum 3.

In the apparatus configured as described above, the pressure inside the vacuum chamber 1 is reduced by the vacuum pump 6, preferably lo-5 to lo-10.
While reducing the pressure to 2 Torr, inert gas G is introduced. When the evaporative material M is heated in this state, evaporation occurs in the gas, and the evaporated material M continuously adheres to the surface of the rotating drum 3. This adhered material M is scraped off by the scraping blade 10 and collected in the collection box 4.

The next new material is adhered to the surface of the rotating drum 3 from which the material M has been scraped off. In this way, the material M is continuously attached and scraped off the surface of the rotating drum 3.

Therefore, the material adhering to the surface of the rotating drum 3 is quickly scraped off without receiving radiant heat from the heat source for heating the material again, so there is no deterioration due to heat (thermal damage) and it is possible to obtain high-quality ultrafine particles. I can do it. The time from evaporation deposition to scraping can be set, for example, by adjusting the rotation speed of the rotary drum 3.

As mentioned above, when the ultrafine particles collected in the actual collection box 4 reach a certain amount, the evaporation operation in the gas is completed, and
The vacuum chamber 1 is opened and taken out.

In the above example, the evaporable material was supplied to the storage container in a batch manner, but a large amount of evaporation treatment is possible if the material is continuously supplied to the heating container in the vacuum chamber using a screw feeder or the like.

Substantially water-insoluble photographic additives that can be used in the present invention are solid additives, and specifically include the following. These include spectral sensitizing dyes, antifoggants, color couplers, dyes, sensitizers, hardeners, ultraviolet absorbers, antistatic agents, brighteners, desensitizers, developers, antifading agents, mordants, and the like.

Regarding these additives, please refer to Research Disclosure (RESEARCH DISCLO5URE, hereinafter R).
Marked as D) vol, 176 RD-17643p, 2
~31 (1978).

Examples of the spectral sensitizer include methine dyes such as cyanine dyes, merocyanine dyes, hemicyanine dyes, rhodacyanine dyes, oxonol dyes, and hemioxonol dyes. Among these dyes, anionic dyes such as dyes having one, preferably two or more sulfo groups or sulfoalkyl groups as substituents are effective.

As a spectral sensitizer, in addition to the above-mentioned publications, German Patent No. 9
No. 29.080, U.S. Patent No. 2.493748, No. 2,
No. 503゜776, No. 2,519,001, No. 2,9
No. 12,329, No. 3,656゜959, No. 3,67
No. 2.897, No. 3,694.217, No. 4, 02
5.

No. 349, No. 4,046,572, No. 2,688,5
No. 45, No. 2,977゜229, No. 3,397.06
No. 0, No. 3,522,052, No. 3,527゜641
No. 3,617.293, No. 3,628.964, No. 3,666゜480, No. 3,672.898,
3,679.428, 3,703°377, 3,814.609, 3,837.862, 4
,026°707, British Patent No. 1,242,588,
1,344.281, 1,507.803, Special Publication No. 44-14030, 52-24844, 4
No. 3-4936, No. 53-12375, JP-A No. 1983-
No. 110618, No. 52-109925, No. 50-8
The one described in No. 0827 is used.

Other than spectral sensitizing dyes, benzotriazole compounds, 4-thiazolidone compounds, benzophenone compounds, cinnamic acid ester compounds, butadiene compounds, benzoxazole compounds, cationic polymer chromium salts,
Aldehydes, N-methylol compounds, dioxane derivatives, active vinyl compounds, active halogen compounds, mucohalogen acids, nitroindazoles, triazoles, benzotriazoles, benzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, tetraazaindene Examples include 5-virazolone capra, vilazolone benzimidazole coupler, acylacetamide coupler, naphthol coupler, and phenol coupler.

When the ultrafine particles obtained in the present invention are used together with an aqueous protective colloid solution, sufficient photographic performance can be obtained whether the ultrafine particles are added in the form of a sol solution or in the form of a gel.

Alternatively, it can be mixed with a protective colloid, stored at a low temperature of 30° C. or lower or refrigerated, and added to a silver halide photographic emulsion if necessary.

The protective colloid used here may be any one that functions as a hydrophilic protective colloid. For example, gelatin,
These include carboxymethyl cellulose, cellulose sulfate, and polyvinyl alcohol. Among these, gelatin is more preferred as the protective colloid.

These protective colloids may be added as an aqueous solution or as a solid. Further, when adding the protective colloid, a known preservative can be used as necessary.

The amount of a substantially water-insoluble photographic additive added to a silver halide photographic emulsion cannot be unambiguously stated depending on the type of additive, the amount of silver halide, etc., but it can be added using conventional methods. An amount approximately equivalent to that used can be used.

In the silver halide photographic emulsion used in the present invention, any of silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide, silver chloride, etc. may be used as silver halide grains. The grain size of the silver halide grains is not particularly limited, but it is practically 5 μm or less, preferably 3 μm or less. These silver halide photographic emulsions have p. Written by GlafkidesC
himie et Physique Photogr
aphique (published by Paul Montel, 19
1967), G. F. Written by Duffin Photogra
phic Emulsion Chemistry (
The Focal Press, 1966),
V. L. Making by Zelik+an etal
and Coating Photographic
Emulsion (The Focal Pr.
ess, 1964).

That is, any of the acidic method, neutral method, ammonia method, etc. may be used, and the method for reacting the soluble silver salt with the soluble halogen salt may be a single jet mixing method, a double jet mixing method, a combination thereof, etc. Good too.

A method in which particles are formed in an excess of silver ions (so-called back mixing method) can also be used. As one form of the double jet mixing method, a method of keeping the pH of the liquid phase in which silver halide is produced constant, that is, a so-called controlled double jet method can also be used.

According to this method, a silver halide emulsion having a regular crystal shape and a nearly uniform grain size can be obtained.

Two or more types of silver halide emulsions formed separately may be mixed and used.

In the process of silver halide grain formation or physical ripening,
A cadmium salt, a zinc salt, a lead salt, a thallium salt, an iridium salt or a complex salt thereof, a rhodium salt or a complex salt thereof, an iron salt or an iron rust salt, etc. may be present together.

These silver halides may be of the disk type that forms latent images mainly on the surface, or of the type that forms latent images inside the grains.

Various other additives can be used in the silver halide photographic emulsion used in the present invention.

That is, the chemical sensitizers include sensitizers known to those skilled in the art such as sulfur sensitizers, gold sensitizers, selenium sensitizers, reduction sensitizers, etc., and these can also be used in combination. . As the sulfur sensitizer, for example, sodium thiosulfate, thiourea, allylthiourea, etc. can be used, and as the metal sensitizer, for example, sodium chloroaurate, potassium gold thiocyanate, etc. can be used. Furthermore, as a gold-sulfur sensitizer, chemical sensitization can be carried out by using at least one type of each of the above-mentioned sensitizers in combination. In this case, ammonium thiocyanate etc. It is also possible to do so. Furthermore, the silver halide emulsion used in the present invention can be subjected to a selenium sensitization method in addition to the upper L sensitization method, for example, as described in US Pat. , No. 574.944, No. 3,591.385, Japanese Patent Publication No. 43-13849, and Japanese Patent Publication No. 44-15748 may be employed. Furthermore, as the reduction sensitizer, conventionally known sensitizers can be used. For example, aging can be carried out using a low p/kg atmosphere, an appropriate reducing agent, or electromagnetic waves such as light and γ rays. In addition to sensitizers, stabilizers, surfactants, hardeners, thickeners, dyes, ultraviolet absorbers, antistatic agents, brighteners, desensitizers, developers, anti-fading agents, and mordants. etc. can be used. Furthermore, couplers such as color-forming couplers can also be used.

Regarding these photographic additives, see RD-17643゜vol, 176, p-22-31 (1978), TI
(E THEORY OF THE PH0TOGRA
PHIC PROCESS (4th Ed,), T, H
, edited by James (1977, Macmillan P.
Publishing Co., Inc.) etc.

The binder used in the silver halide emulsion of the present invention is preferably gelatin, but in addition to gelatin, derivative gelatin such as pentatalated gelatin, albumin, agar, gum arabic, cellulose derivatives, polyvinyl acetate, polyacrylamide, polyvinyl Alcohol etc. are used.

〔Example〕

Next, the present invention will be explained in more detail based on examples. However, the present invention is not limited to this embodiment.

Example 1 The vacuum chamber of the apparatus shown in FIG.
The mixture was heated to 00 to 330°C and evaporated in vacuum to obtain ultrafine particles.

As a result, ultrafine particles without thermal deterioration could be collected with a yield of about 50%.

Example 2 Under the same conditions as in Example 1, the change in actual particle size with respect to the rotational speed of the rotating drum, that is, the scraping speed was investigated. The results are shown in FIG. As a result, it was found that the particle size depended on the scraping speed, and it was therefore found that the particle size could be controlled by adjusting the rotational speed of the rotating drum.

The ultrafine grains of the spectral sensitizing dye with a grain size of about 0.5 μm obtained in Example 2 were mixed into a silver iodobromide emulsion (average grain size 0.65 μm, average silver iodobromide content) obtained according to a conventional method. 6゜8mo
le% silver iodobromide grains (octahedron)), while the same spectral sensitizing dye was dissolved in a mixed organic solvent of 1,1.2.2-probyl tetrafluoride alcohol and methyl alcohol. , which was added to the above-mentioned silver iodobromide photographic emulsion, and the spectral sensitizing dye adsorption determined from the centrifuged supernatant of both was the same after 15 minutes.

〔Effect of the invention〕

Even if an ultrafine grain photographic additive is added to a silver halide photographic emulsion in powder form by the production method of the present invention, the time required for adsorption onto the silver halide grains decreases as the grains of the photographic additive become finer. This increase in specific surface area eliminates the need for long time counting, and also prevents coating failures due to precipitation etc. during coating of silver halide photographic emulsions. Additionally, when dispersing substantially water-insoluble photographic additives into an aqueous system, wetting agents and dispersants, which were previously thought to be essential, are no longer required, resulting in the destruction of emulsions, adverse effects on high-speed coating, and Problems such as poor film adhesion were prevented, and furthermore, the state of adsorption of photographic additives to silver halide grains was improved.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the vapor deposition apparatus used in the present invention, Fig. 2 is a schematic diagram of an example in which the vapor deposition section is an endless belt, and Fig. 3 shows the relationship between the rotation speed of the rotating drum and the particle diameter of the ultrafine particles obtained. It is a correlation diagram.

Claims (2)

[Claims] (1) In a method for producing a silver halide photographic emulsion in which a substantially water-insoluble photographic additive is added to a silver halide photographic emulsion, the photographic additive is reduced to fine particles by evaporation in a gas, and the halogen A method for producing a silver halide photographic emulsion, which comprises adding the fine particles in powder form to a silver halide photographic emulsion, or adding the fine particles by dispersing or mixing them in an aqueous solution or a protective colloid aqueous solution. . (2) In a light-sensitive material having at least one silver halide photographic emulsion layer on a support, the silver halide photographic emulsion layer contains the silver halide photographic emulsion produced by the manufacturing method of claim 1. A photosensitive material characterized by: