JPH0223330A - Production of silver halide emulsion - Google Patents

Abstract

PURPOSE:To prevent the generation of a lumpy or stripe like coating trouble by making a water-insoluble photographic additive together with an easily water-dispersible or an easily water-dissoluble photographic additive to a flake like concentrate, followed by dispersing it into water, and then, incorporating the obtd. dispersion in the silver halide emulsion. CONSTITUTION:The photographic additive which is substantially insoluble in the water, together with one or more kinds of the easily water-dispersible or the easily water-dissoluble photographic additives are dissolved in an org. solvent, while heating, and then the solvent of an obtd. solution is evaporated to form the flake-like concentrate, and further, the concentrate is dispersed in the water, followed by incorporating the obtd. dispersion in the silver halide emulsion. The evaporating condition for making the flake-like concentrate lies in a temp. of less than the decomposition temp. of the photographic additive under a prescribed reduced pressure. Thus, as the org. solvent is not directly added to the emulsion, and the additional amount of a surfactant is small, the coating trouble caused by the generation of a precipitate etc., at the time of coating the emulsion is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a silver halide emulsion. In particular, it relates to a method of adding a substantially water-insoluble photographic additive to a silver halide emulsion as an aqueous dispersion by changing its crystalline state.

(Prior Art) Conventionally, when various water-insoluble photographic additives are added to silver halide photographic emulsions, Rf& of the water-insoluble photographic additives dissolved in an organic solvent is mixed with water or an aqueous solution containing an anionic surfactant. Alternatively, a method has been used in which the cough dispersion is added to an aqueous solution or a hydrophilic colloid solution containing an aqueous binder, recrystallized, and dispersed in an easily dispersed crystalline state, and then the cough dispersion is added to a silver halide emulsion.

Examples of methods using a mechanical dispersion method to make the portion 11 include, for example, U.S. Pat.
660.101 and Japanese Patent Publication No. 49-46416.

Furthermore, JP-A-49-128725 discloses a method in which a dispersion in water is formed by recrystallizing in the same manner as described above and then removing the organic solvent.

Furthermore, completely different from the above, pH 6 to 8.6 under conditions substantially free of organic solvent and/or surfactant.
There is a method in which a substantially water-insoluble photographic additive is mechanically dispersed in water at a temperature of 0 to 80°C, and the resulting dispersion is added to a silver halide emulsion (Japanese Patent Publication No. 1983-1999). 452
Publication No. 17).

[Problem to be solved by the invention]

However, when dissolving various water-insoluble photographic additives in organic solvents, especially when using photographic additives that are poorly soluble in organic solvents, it is necessary to add a large amount of organic solvent to the silver halide emulsion. In this case, there were problems such as the formation of aggregates and the occurrence of lump-like or streak-like coating failures when coating the silver halide emulsion.

In addition, the method of recrystallizing in the same way as above and then removing the organic solvent to form a dispersion in water uses evaporation or membrane separation as the process for removing the organic solvent, so the solution after evaporation treatment is There are problems such as variations in the concentration of the solution and decomposition of the composition, and when a membrane separation method is used, variations in the concentration of the solution after membrane separation occur, and the manufacturing process is also complicated.

Although the method disclosed in Japanese Patent Publication No. 61-45217 is an excellent method, some photographic additives are not dispersed and remain as coarse crystals (5 to 30 .mu.m). In other words, it has been found that there are some photographic additives that cannot be mechanically dispersed unless the crystalline state is changed in some way.

The present applicant has solved the above problems, and can easily disperse water-insoluble photographic additives into emulsions without causing coating failures such as lumps or streaks, without variations in the concentration of the additive solution, and without decomposition of the composition. As a method for producing a silver halide emulsion that can be added, first, a substantially water-insoluble photographic additive is mixed with an organic solvent, a surfactant having a 40i--O503 group as a hydrophilic group, and, if necessary, It is characterized by heating and dissolving in a small amount of a base or a mixture of a base and an acid, dropping the solution into water to recrystallize it, dispersing it with a dispersion machine, and adding the dispersion to the halogenated emulsion. We proposed a method for producing silver halide emulsions.

Although the above-mentioned method is an excellent method, the solution added to the silver halide emulsion contains an organic solvent, which may cause streak-like or lump-like coating failures during coating. In order to further improve this problem, it has been desired to not include an organic solvent.

The purpose of the present invention is to solve the above-mentioned problems, and to make it possible to add water-insoluble photographic additives without containing organic solvents, without causing coating failures such as lumps or streaks, without variations in concentration or decomposition of the additive solution. A method for producing a silver halide emulsion is provided.

(Means and effects for solving the problems) The above object of the present invention is to heat a substantially water-insoluble photographic additive together with 11 or more crystal-dispersible or easily water-soluble photographic additives in an organic solvent. It is characterized by dissolving, and after complete dissolution, evaporating the solvent of the solution to form a flake-like concentrate, dispersing the flake-like concentrate in water, and adding the dispersion to a silver halide emulsion. This is achieved by a method for producing a silver halide emulsion.

To explain the present invention in more detail, the substantially water-insoluble photographic additives that can be used in the present invention are solid additives, and specifically include the following. Spectral sensitizing dyes, antifoggants, color couplers,
These include dyes, sensitizers, hardeners, ultraviolet absorbers, antistatic agents, brighteners, desensitizers, developers, anti-fading agents, and mordants.

For these additives, RESEARCHDTSC
LOSURE vol, 176 RD-17643pa
ge22-31 (December 1978).

For example, examples of the spectral aggravating agent include methine dyes and styryl 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 the spectral sensitizer, in addition to the above-mentioned publications, those described in the following publications can be used. German patent 9290
No. 80, U.S. Patent No. 2493748, U.S. Patent No. 2503776
No. 2519001, No. 2912329, No. 36
No. 56959, No. 3672897, No. 3694217
No. 4025349, No. 4046572, No. 26
No. 88545, No. 2977229, No. 3397060
No. 3522052, No. 3527641, No. 36
No. 17293, No. 3628964, No. 3666480
No. 3672898, No. 3679428, No. 37
No. 03377, No. 3814609, No. 3837862
No. 4026707, British Patent No. 1242588,
No. 1344281, No. 1507803, Special Publication No. 1977
-14030, 52-24844, 43-49
No. 36, No. 53-12375, JP-A No. 52-1106
No. 18, No. 52-109925, No. 50-80827
It is stated in each publication.

Examples of substances other than spectral sensitizers include the following. That is, benzotriazole compounds,
4-thiazolidone compounds, benzophenone compounds, cinnamic acid ester compounds, butadiene compounds, penduoxazole compounds, cationic polymers, chromium salts, aldehydes, N-methylol compounds, dioxane derivatives, active vinyl compounds, active halogen compounds, mucohalogen acids , nitroindazoles, triazoles, benzotriazoles, benzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, tetraazaindenes, 5-pyrazolone couplers, pyrazolone benzimidazole couplers, acylacetamide couplers, naphthol couplers, phenol couplers, etc. can be mentioned.

The amount of the substantially water-insoluble photographic additive added to the silver halide emulsion cannot be determined unambiguously depending on the type of additive and the silver halide pattern, but it can be added by conventional methods. Approximately the same amount can be used.

However, the present invention is effective when the water-insoluble photographic additive is a photographic spectral sensitizing dye belonging to cyanine dyes.

As an example, (Hereafter, this will be referred to as dye A) can be mentioned.

In the present invention, a quartz crystal dispersible or easily water-soluble photographic additive is a photographic additive that can be easily dispersed or dissolved in water by mechanical stirring without using a wetting agent or dispersant. , for example.

As the organic solvent used in the present invention, organic solvents belonging to alcohols are preferable. Examples include aliphatic saturated alcohols, aliphatic unsaturated alcohols, alicyclic alcohols, aromatic alcohols, heterocyclic alcohols, and aromatic primary alcohols or halogenated alcohols are particularly preferred.

For example, benzyl alcohol (CaHsC)
, fluorinated alcohol.

In the silver halide emulsion used in the present invention, any of silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide, silver chloride, etc. may be used as the silver halide.

The grain size of silver halide is not particularly limited, but it is 3
It is preferably less than μ. These silver halide emulsions can be easily prepared by the method described in the following literature. Chimie et by P, GIafkides
Physique Photography
e (Paul Monte1, 1967)
, Photographic by G.F. Duffin
Emulsion ChevAiStry (The
Focal Press, 1966), V.L.
Making and by Zelikman et at
CoatingPhotographic Ell
ulsion (The Focal Press, 1
964), etc.

In other words, 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 one-sided mixing method, a simultaneous mixing method, a combination thereof, etc.). good.

It is also possible to use a method in which particles are formed under an excess of negative ions (so-called back-mixing method).

As one type of simultaneous mixing method, a method in which PAg in the liquid phase in which silver halide is produced can be kept constant, that is, a so-called Chondrald 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 complex salt, etc. may be present.

Various other additives can be used in the silver halide emulsion used in the present invention. In other words, sulfur sensitizers, reduction aggravators, noble metal sensitizers and other sensitizers, stabilizers, surfactants, hardeners, thickeners, dyes, ultraviolet absorbers, antistatic agents, brighteners, and thinners. Sensitizers, developers, anti-fading agents, mordants, etc. can be used. Furthermore, a coupler such as a color coupler can also be used by dispersing it in oil.

For these additives, R[! 5EARCHDIS
CLOSURE (RD-17643), vol, 17
6, Pages 22-31 (Dec-ember 1
978), THE! THEORY OF TH[!
PH0TOGRAPHIC PROCESS (4th
[! d,) T, LJames I (1977, M-
Acmillan Publishing Co, I
nc, ) 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 phthalated gelatin, albumin, agar, gum arabic, cellulose derivatives, polyvinyl acetate, polyacrylamide, polyvinyl alcohol etc. are used.

The method for producing the silver halide emulsion in the present invention includes:
First, a weighed amount of organic solvent is placed in a tank, a substantially water-insoluble photographic additive is added to the organic solvent along with one or more water-readily dispersible photographic additives, and the temperature is heated to 70-90°C. Heat and dissolve. For the melting tank, the stirring blade is, for example, a turbine blade with four blades on the stirring shaft, and the ratio of its diameter to the tank inner diameter is about 5 to 2:5, and the ratio between the diameter of the turbine blade and the bottom of the tank is The gap ratio between the turbine blade and the turbine blade is 2:1~
It is desirable to set the ratio between the diameter of the turbine blade and the depth of the static liquid in the tank to be about 1:1 to 1:3.

However, in this case, the stirring blade is not limited to a turbine blade, and paddle blades, propeller blades, day silver blades, etc. may also be used.

For small quantity adjustment, a magnetic stirrer can be used.

In this case, -so, as a hydrophilic group toward organic solvents,
A surfactant having a group -osot may also be added.

Examples of cough surfactants include anionic surfactants such as alkyl sulfates, alkyl sulfonates, alkylaryl sulfonates, and sulfosuccinate ester salts.

especially is preferred.

In the present invention, in the organic solvent, -3OS, as a hydrophilic group,
When adding and mixing a surfactant having a -0502 group, although it varies depending on the type of organic solvent and surfactant,
When the two are dissolved in a mixed solution, the effect of improving dispersibility is increased by adding the surfactant in an amount of 5 to 50% by weight based on the total amount of photographic additives.

Next, the organic solvent in the solution after complete dissolution as described above is evaporated to form a flaky i4 condensate.The evaporation conditions are below the decomposition temperature of the photographic additive and under an appropriate residual pressure. Preferably, the evaporation is carried out at .

The amount of residual solvent in the flaky condensate is 1% by weight or less based on the total amount of photographic additives.

The obtained flake-like crystals become a eutectic product with the water-easily dispersible additive, and therefore have excellent dispersibility in water.

Add the flaky agglomerate thus obtained to water,
I at pl+6.5-7.5 under heating conditions of 0-60°C
N.

After adjusting with NaOH, dispersion is carried out using a high-speed stirrer.The high-speed stirrer used in this case is as shown in Fig. 1 (a) and (b).
It is preferable to use daysilver blades as the blade.

The ratio of the diameter of the Daysilver blade to the inner diameter of the tank is 1:5 to 2.
: About 5, the ratio of the diameter of the daysilver blade and the gap between the bottom of the tank and the daysilver blade is about 2:1 to 1:1, and the ratio of the diameter of the daysilver blade to the stationary liquid in the tank is 1:1 to 1. :3
degree is preferred.

The dispersion may be added directly to the silver halide emulsion as it is, or it may be mixed with a protective colloid and then added in the form of a solution, or it may be added in the form of a gel to obtain sufficient photographic performance. I can do it.

Preferred embodiments of the present invention are as follows.

(1) A method for producing a silver halide emulsion according to claim 1, characterized in that the substantially water-insoluble photographic additive is a photographic spectral sensitizing dye belonging to cyanine dyes. .

(2. In Claim 1 or Embodiment (]), the amount of the surfactant having a -3Oa+-0303 group is 5 to 50% by weight based on the total amount of photographic additives. A method for producing a silver halide emulsion characterized by:

〔Example〕

Example-1 Dye A described above as a substantially water-insoluble photographic additive
1.59 g was added to 100 g of fluorinated alcohol as an organic solvent along with 88.12 g of the above-mentioned dye as a water easily dispersible photographic additive and 0.3 g of the above-mentioned dye C, and heated to 80-85 ° C. Melting is carried out for 20 minutes while stirring with a turbine blade.

After complete dissolution, the solvent is evaporated in direct air at 80"C and 1 to 2 mHH for 1 hour to produce a flake-like condensate. At this time, the residual solvent in the flake-like concentrate is 1% of the total amount of photographic additives. % by weight or less.The resulting flaky crystals form a eutectic product with the water-easily dispersible additive, resulting in excellent dispersibility in water.

This flaky concentrate was then added to 500 ml of water,
The pH was adjusted to 7 with 1N Naoll, and dispersion was carried out over a period of about 2 hours at a temperature of 50° C. using a Daysilver blade as shown in FIG. 1 as a high-speed stirrer at 300 Or, ρ, s.

Comparative Example-1 Dye A described above as a substantially water-insoluble photographic additive
Add only 1.59g to 16g of fluorinated alcohol, 8
Heat to 0-85°C and stir with a turbine blade for 20 minutes.
Perform lysis for minutes.

After complete dissolution, the solvent is evaporated in a vacuum at 80"C and 1 to 2 mmHg for 1 hour to produce a flake concentrate. At this time, the residual solvent in the flake concentrate is 1% by weight based on the photographic additive. The following shall apply.

Next, this flake-like concentrate was used as a water easily dispersible photographic additive.
, 500s+ water with 3gr 1. Example-
Dispersion was performed under the same conditions as 1.

When the dispersion of Example-1 and the dispersion of Comparative Example-1 were observed with a 400x optical V&mirror, dispersion in Example-1 was completed to particles of 1 μ or less, but in Comparative Example-1 Coarse crystals (10-70μ level) occupied 10'g of the microscopic field of view.

The method of the present invention is an excellent dispersion method.

[Effects of the Invention] As shown above, the production method of the present invention does not require adding an organic solvent directly to the silver halide emulsion, and the amount of surfactant added is small, so that no precipitates are formed during emulsion coating. There is no possibility of coating failure due to etc. Furthermore, it has been possible to provide a manufacturing method in which a water-insoluble photographic additive can be added to a silver halide emulsion without containing an organic solvent without causing variations in concentration or decomposition of the composition of the additive solution.

[Brief explanation of the drawing]

FIG. 1 is a side view (a) of the installed state of a high-speed stirrer used for producing the dispersion of the present invention, and a perspective view (c) of the day silver blade of the high-speed stirrer. 1...Tank 2...Liquid to be dispersed 3...Daysilver blade/stirring shaft 31...Disc Fig. 32, 33 -Veil (q)

Claims (1)

[Claims] (1) A substantially water-insoluble photographic additive is heated and dissolved in an organic solvent together with one or more crystal dispersible or easily water-soluble photographic additives, and after complete dissolution, the organic solvent of the solution is removed. A method for producing a silver halide emulsion, which comprises evaporating to form a flake concentrate, dispersing the flake concentrate in water, and adding the dispersion to a silver halide emulsion.