JPH0268136A - Emulsifying dispersion method - Google Patents

Abstract

PURPOSE:To reduce bubble formation and heighten the efficiency of solvent removal by keeping the viscosity of a foaming and hydrophilic colloidal solution, which contains water and a solvent having lower boiling point than water, at a value higher than a specified value at the finishing time of emulsifying dispersion of the solution. CONSTITUTION:In emulsifying dispersion of a material such as a photosensitive material, a foaming and hydrophilic colloidal solution containing water and a solvent such as ethyl acetate having a lower boiling point than water is emulsified and dispersed. In this case, the viscosity of the colloidal solution is set to be >=1000cp at the finishing time of dispersion. During the period from the later stage of emulsifying dispersion to the stage after the finish, a vacuum pump 5 is connected to an emulsifying and dispersing tank 1 and an unnecessary solvent having a lower boiling point than water is removed periodically. Because the viscosity of the resulting emulsion is selectively set to be >=1000cp, the emulsifying tank is not filled with foams and also the foams are not moved to a pressure reducing pipes. Vacuum distillation is thus carried out smoothly and the solvent is removed speedily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to an emulsification and dispersion method for obtaining photographic materials and the like.

[Prior art] This type of oil-in-water emulsion is used in Nichoshin photosensitive materials, as well as
It is widely used for manufacturing cosmetics, foods, paints, drugs, etc.

For example, in photographic materials, color image-forming compounds (
An emulsion is obtained by using oil-soluble substances such as a coupler), a compound for diffusion transfer, a color antifogging agent, an antifading agent, an anticolor mixing agent, an ultraviolet absorber, and a whitening agent. In general, to prepare oil-in-water emulsions of these oil-soluble substances, first, if the oil-soluble substances are liquid, they may be used as is, or if necessary, together with an organic solvent or an emulsifying agent, or an emulsifying agent dissolved in an organic solvent. An oil phase solution (hereinafter simply referred to as "oil phase solution") prepared by heating or dissolving the oil-soluble substance in an organic solvent, or by dissolving it in an organic solvent together with an emulsifying agent if the oil-soluble substance is solid. ) is added onto the liquid surface of an aqueous phase solution (hereinafter simply referred to as "aqueous phase solution") containing a water-soluble binder to which an emulsifying aid has been added as necessary, and emulsified and dispersed to give a concentration of about 0.1 to It was prepared as an oil-in-water emulsion with an average particle size of 1.0 μm.

As the organic solvent mentioned above, a solvent with a boiling point lower than that of water, such as ethyl acetate, is often used. Since this solvent is unnecessary once dispersion is complete, a vacuum pump is connected to the emulsification tank to reduce the pressure inside the emulsification tank. It is preferable to remove it by doing this.

On the other hand, many formulations containing a large amount of photographic material exhibit foaming properties when emulsified and dispersed.

[Problems to be Solved by the Invention] However, when this foamable hydrocolloid solution is emulsified and dispersed, bubbles fill the emulsification tank, reducing the evaporation area.
In addition to not being able to remove the solvent smoothly, when attempting to remove the solvent during vacuum distillation, bubbles migrate into the exhaust pipe, resulting in a large amount of loss. The inside of the exhaust pipe must be cleaned.

In addition, as a method for removing the organic solvent, there are a method of first gelling it and then washing with water, a method of heating to evaporate the solvent, a method of spraying it as droplets into a pressure reducing pipe as in JP-A-53-112731, or a method of spraying the solvent into a vacuum tube as described in JP-A-53-112731. A separation method using a microporous membrane is known, as disclosed in Japanese Patent Publication No. 74031/1983, but apart from droplet spraying, the solvent removal time is long and the removal rate is not high. In addition to the problem with the thermal evaporation method, the liquid may be denatured by heat. Although the droplet atomization method does not have such problems, the equipment cost is high.

On the other hand, it is also known to suppress the generation of bubbles itself. A typical example is to use an antifoaming agent, but there is a high possibility that the liquid will be denatured. In addition, a stirring blade is separately installed above the liquid surface,
Method of breaking bubbles by colliding with bubbles (Japanese Patent Application Laid-Open No. 61-54
213), a method of irradiating with far infrared rays or laser light (Japanese Patent Application Laid-open No. 62-269718), and a method of leaking into the outside air (Japanese Patent Application No. 59-25584), but these methods require high equipment costs and are difficult to emulsify. Currently, there is no definitive solution, as there are problems such as difficulty in cleaning the inside of the tank.

Therefore, the main object of the present invention is to provide an emulsification and dispersion method that generates fewer bubbles and has excellent solvent removability.

[Means for Solving the Problem] The above problem is achieved when dispersing a foamable hydrophilic colloidal solution containing water and a solvent with a boiling point lower than that of water;
This is achieved by forming an emulsified dispersion having a concentration of 0 cp or more, and removing the solvent from the dispersion tank by vacuum distillation at the end of dispersion and/or after dispersion.

[Function] In the present invention, since the viscosity at the end of dispersion is selected to be 1000 cp or more, there is little generation of bubbles, the emulsification tank is not filled with bubbles, and of course there are no bubbles in the vacuum piping. Since there is no migration, vacuum distillation can be carried out smoothly. Furthermore, since the solvent is removed by vacuum distillation, the removal efficiency is higher than that of other methods.

[Specific examples of the invention] The present invention will be explained in more detail below.

The main point of the present invention is to use a foamable hydrophilic colloid solution containing water and a solvent having a boiling point lower than water, which has a viscosity of 1000 cp or more at the end of emulsification and dispersion.

The viscosity is measured using a B-type viscometer. The viscosity is preferably 3,000 to 100,000 cp, especially 5,000 to 5,000 cp.
0 cp is preferred. In order to obtain such a viscosity for a given liquid composition, the ratio of the oil phase solution to the aqueous phase solution (
0/W ratio) and the concentration of the binder, such as gelatin.

Next, an explanation will be given while showing an example of emulsification and dispersion equipment shown in FIG.
．． 2.3 is provided with a high speed stirrer IA and stirrs 2A and 2B, respectively.

As the high-speed agitator IA, a Daysilver type, a seed type, a propeller type, a homomixer type, etc. are adopted. A membrane scraper 4 is rotatably disposed within the emulsification dispersion tank 1 with a clearance of preferably 1 cm or less from the inner surface.

The emulsification dispersion tank 1 has a closed structure, and a vacuum pump 5 is connected to it, and the vacuum pump 5 is operated continuously or intermittently.
From the end of the emulsification dispersion to the end of the emulsification dispersion, unnecessary solvents having a boiling point lower than water, such as ethyl acetate, are removed.

6 is a heating or insulation jacket, and 7 is a cooling jacket, the functions of which will be described later.

In such emulsification equipment, for example, an aqueous phase mixing tank 2
After the aqueous phase solution and the oil phase solution are prepared in each of the oil phase preparation tank 3 and the aqueous phase solution W, a predetermined amount of the aqueous phase solution W is supplied into the emulsification dispersion tank 1 via the supply pipe 8. Next, after rotating the high-speed stirrer IA, the prepared oil phase solution
is added to the aqueous phase solution in the emulsification dispersion tank 1 via the submerged addition pipe 9 at a rate of addition of preferably 30 to 4517 m.

Thereafter, emulsification and dispersion is carried out, preferably with the rotational speed of a high-speed stirrer being increased, until the desired particle size is finally achieved.

From the final stage of this emulsification dispersion, preferably after the end of emulsification dispersion,
The vacuum pump 5 is started to reduce the pressure in the emulsification dispersion tank 1 to remove a solvent having a boiling point lower than water, such as ethyl acetate. The degree of pressure reduction is preferably 50 to 200 Torr.

The obtained emulsion is applied onto a support in the case of a photographic material.

In the above example, in order to improve the emulsion dispersibility and remove unnecessary solvents, a heating means such as a heating jacket 6 through which hot water flows is provided to heat the emulsion liquid, and this heating jacket 6 is connected to the liquid level of the emulsion liquid. Preferably, they are arranged lower, more preferably at least 5 cm apart.

In addition to the arrangement of the heating jacket 6, it is more preferable to provide a cooling means, for example, a cooling jacket 7 for passing cold water from below to above the liquid level, in order to prevent drying at the liquid level and above it.

The heating jacket 6 and the cooling jacket 7 may be divided in the height direction or the circumferential direction depending on the case.

In addition to water, other liquids may be used as the heat medium, and for example, a heater or the like may be used as the heat source. Further, the heating or cooling means does not necessarily have to be placed inside the tank 1, and one possible embodiment thereof is to arrange a heat exchanger tube therein.

Heating and cooling temperatures are not limited, and only need to be relatively high temperature at the bottom and low temperature at the top, but when the unnecessary solvent is ethyl acetate, the heating (hot water) temperature is 60 to 65 ° C.
The cooling (cold water) temperature is preferably from 5 to 15°C, preferably at most 30°C.

In the present invention, the types of oil phase solution and aqueous phase solution are not limited, but since the present invention is particularly suitably applied to the production of emulsions of photographic light-sensitive materials, this will be explained below.

That is, couplers used as oil-soluble substances when applied to various photographic materials include color image-forming compounds that form dyes by reacting with the oxidation products of color developing agents, such as aromatic amines (usually primary amines). Generally, it is preferable that the coupler molecule has a hydrophobic group called a ballast group and is non-diffusible, and may be either 4-equivalent or 2-equivalent to silver ions. The couplers include colored couplers that have a color correction effect, and so-called DIR couplers that release a development inhibitor during development. Among the above couplers, a known closed ketomethylene coupler can be used as the yellow coloring coupler. Among these, benzoylacetanilide and pivaloylacetanilide compounds are advantageous.

Further, as the magenta coloring coupler, pyrazolone compounds, indacylon compounds, cyanoacetyl compounds, etc. can be used, and pyrazolone compounds are particularly advantageous.

Further, as the cyan color-forming coupler, phenol compounds, naphthol compounds, etc. can be used.

On the other hand, as a colored coupler, for example,
-42121 can be used.

In addition, as a DIR coupler, for example, JP-A-52-
Those described in No. 69624 can be used. Further, in addition to the above DIR coupler, the photographic material may contain a compound that releases a development inhibitor upon development; for example, those described in JP-A-53-9116 can be used.

The diffusion transfer compound includes a dye developer, a diffusible dye-releasing coupler (DDR coupler), a diffusible dye-releasing reducing agent (
DRR compounds).

As the color anti-capri agent, those containing, for example, hydroquinone derivatives, aminophenol derivatives, gallic acid derivatives, and ascorbic acid derivatives are used.

Examples of the anti-fading agent include dihydroxybenzene derivatives, dihydroxynaphthalene derivatives, aminonaphthol derivatives, sulfonamide phenol derivatives, sulfonamide naphthol derivatives, and the like.

The ultraviolet absorber is, for example, a benzotriazole compound substituted with an aryl group, a 4-thiazolidone compound,
A benzophenone compound, a cinnamic acid ester compound, a bucdiene compound, a benzoxyzole compound can be used, and furthermore, an ultraviolet absorbing coupler, an ultraviolet absorbing polymer, etc. may be used.

The brightener is, for example, a stilbenzene-based, triazine-based, oxazole-based, or coumarin-based compound.

For example, in photographic materials, the organic solvent may be one having a relatively high boiling point, such as phthalate alkyl ester, phosphate ester, citric acid ester, benzoate ester, alkylamide, fatty acid ester, etc. Examples of low-boiling organic solvents include lower alkyl acetate, ethyl propionate, secondary butyl alcohol, methyl isobutyl ketone, cyclohexanone, β-ethoxyethyl acetate, and methyl cellosolve acetate.

In photographic materials, the water-soluble binder includes, for example, gelatin, gelatin derivatives, graft polymers of gelatin and other polymers, proteins such as albumin and casein;
1! Cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, cellulose sulfate esters, sodium alginate, starch derivatives, etc. Derivatives: Various synthetic highly hydrophilic compounds such as single or copolymers of polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-vinylvinidrine, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole, polyvinylpyrazole, etc. Molecular substances can be used.

In photographic materials, the emulsification aids include, for example, saponins (steroids), alkylene oxide derivatives (e.g. polyethylene glycol, polyethylene glycol/polypropylene glycol condensates, polyethylene glycol alkyl or alkylaryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan). esters, polyalkylene glycol alkylamines or amides, silicone polyethylene oxide adducts), glycidol derivatives (e.g. alkenylsuccinic acid polyglycerides, alkylphenol polyglycerides), fatty acid esters of polyhydric alcohols, alkyl esters of sugars, Similarly, nonionic surfactants such as urethanes or ethers; triterpenoid saponins, alkyl carboxylates, alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfates, alkyl phosphate esters , N-acyl-N-alkyl taurines, sulfosuccinates, sulfoalkyl polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl phosphates, etc. Carboxy groups, sulfo groups, phospho groups, sulfate ester groups , Aniline surfactants containing acidic groups such as phosphate ester groups; Ampholytic surfactants such as amino acids, aminoalkyl sulfonic acids, aminoalkyl sulfates or phosphoric esters, alkyl betaines, amine imides, amine oxides: Alkyl amines Cationic surfactants such as salts, aliphatic or aromatic quaternary ammonium salts, heterocyclic quaternary ammonium salts such as pyridinium, imidazolium, and phosphonium or sulfonium salts containing aliphatic or heterocycles can be used.

〔Example〕

Next, the effects of the present invention will be clarified by examples.

That is, the emulsifying and dispersing device shown in FIG. 1 was used.

The inner diameter of the emulsification dispersion tank is 300mmφ, and the maximum height is 300m.
, a Daysilver type high-speed stirrer with a blade diameter of 100 and a diameter of 7.
It was rotated for 30 minutes at 50 rpm. During this emulsification and dispersion, the temperature of hot water to the heating jacket was 45°C, and the temperature of cold water to the cooling jacket was 20°C.

After the emulsification and dispersion was completed, hot water at 60°C was passed through the heating jacket, and while the water flow to the cooling jacket was stopped, the vacuum pump was started to reduce the pressure inside the emulsion dispersion tank, and the ethyl acetate was removed for 30 minutes. I went for a minute.

The above operations were carried out on six kinds of foaming parent wood colloid solutions with different formulations, and the relationship between the viscosity at the end of dispersion and the foaming height was investigated, and the results shown in FIG. 2 were obtained. In addition, when the solvent removal rates were investigated for the three types of liquids with the formulations shown in Table 1, the ethyl acetate removal rates shown in Table 1 were observed. In addition, in solution 1, the liquid foamed violently, and suction of bubbles into the piping was observed.

[Effects of the Invention] As described above, according to the present invention, the generation of bubbles is small and the removability of solvents is excellent.

Ru.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an example of emulsification and dispersion equipment, and FIG. 2 is a correlation diagram between the viscosity at the end of dispersion and the foaming height above the liquid surface. 1... Emulsification dispersion tank, 2... Aqueous phase preparation tank, 3
...Oil phase mixing tank, 5...Vacuum pump. Procedural amendment (voluntary) Figure 2 October 4, 1988 Patent Application No. 220096 2, Title of the invention Emulsification dispersion method 3, Relationship with the case of the person making the amendment Patent applicant address name 4, Agent Person ■ 101 Konica Co., Ltd. Delete the words from ``Additionally, heat or...'' to line 18, ``Kill.'' ■ Page 9, lines 2 to 3, ``5 to 15℃, maximum 30℃
'' was corrected to read ``5-30℃, maximum 45℃.'' ■ On page 15, lines 7 and 8, the phrase ``While circulating water and stopping the flow of water to the cooling jacket,'' was replaced with ``
Let the water circulate, and keep the water flowing to the cooling jacket at 20°C.
I am corrected. Procedural amendment (voluntary) 1. Indication of the case 1988 Patent application 2. Name of the invention Emulsification and dispersion method 3. Person making the amendment Relationship with the case No. 220096

Claims (1)

[Claims] (1) When dispersing a foamable hydrophilic colloidal solution containing water and a solvent with a boiling point lower than water; forming an emulsified dispersion having a viscosity of 1000 cp or more at the end of dispersion as the colloidal solution; An emulsification and dispersion method characterized in that the solvent is removed from the dispersion tank by distillation under reduced pressure at the final stage and/or after dispersion.