JPH0295427A - Method for washing emulsification tank - Google Patents

Abstract

PURPOSE:To efficiently and automatically wash a tank in a short time by carrying out rough washing with warn water, discharging the water, charging an org. solvent into the tank, heating the lower part of the tank and cooling the upper part to reflux the org. solvent. CONSTITUTION:When the inside of an emulsification tank 1 is washed after the production of an oil-in-water type emulsion, warm water is first charged into the tank 1, rough washing is carried out by rotating a stirrer 2 and the waste water is discharged from a discharge pipe. An org. solvent such as ethyl acetate is then charged into the tank 1, a heating jacket 3 around the lower part of the tank 1 is kept at a temp. above the b.p. of the org. solvent and a cooling jacket 4 around the upper part is kept at a temp. below the b.p. of the org. solvent to reflux the org. solvent by evaporation from the lower part and condensation at the upper part. Automatic washing can be carried out in a short time and the tank is cleaned.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for cleaning an emulsification tank when producing an oil-in-water emulsion for the purpose of obtaining photographic light-sensitive materials.

[Conventional technology]

This type of oil-in-water emulsion is widely used for producing cosmetics, foods, paints, medicines, etc. as well as photographic materials.

For example, in photographic materials, color image-forming compounds (
The emulsifier 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 color additive. The preparation of oil-in-water emulsions of these oil-soluble substances is generally carried out by first adding the oil-soluble substance together with an organic solvent or with an emulsification aid, or an emulsification aid dissolved in an organic solvent, or when the oil-soluble substance is in solid form. For this purpose, an oil phase solution (hereinafter simply referred to as "oil phase solution") prepared by heating or dissolving in an organic solvent, or by dissolving in an organic solvent together with an emulsifying aid (hereinafter simply referred to as "oil phase solution") is added with an emulsifying aid as necessary. an aqueous phase solution containing an added water-soluble binder (
(hereinafter simply referred to as "aqueous phase solution") on the liquid surface and emulsified and dispersed to prepare an oil-in-water emulsion having an average particle size of approximately 0.1 to 1.0 μm.

Each time such emulsification dispersion or multiple times of emulsification 1ik
1& It is necessary to clean the inside of the emulsification tank to remove solidified matter and impurities that adhere to the inner surface.

Conventionally, this cleaning has been done manually, sometimes with a brush rotated by a simple motor, or using a high-pressure nozzle washer.

[Problem to be solved by the invention]

However, the manual brush cleaning method is extremely time-consuming and does not provide a good working environment when using a solvent to remove oil. Furthermore, when using a high-pressure nozzle washer, there are disadvantages in that cleaning residues remain on the back of the stirring blades, where it is difficult to project high-pressure water, and oil cannot be removed sufficiently.

Therefore, the main purpose of the present invention is to shorten the cleaning time,
Another object of the present invention is to provide a cleaning method that is capable of automatic cleaning and has excellent cleaning performance.

[Means to solve the problem]

The above problem arises when cleaning the emulsification tank after obtaining an oil-in-water emulsion by dispersing the emulsion using an emulsification tank equipped with a stirrer; This problem can be solved by performing rough washing, then discharging the hot water, then pouring an organic solvent into the emulsification tank, heating the lower part, cooling the upper part, and washing the solvent under reflux.

[For production]

By roughly washing the inside of the emulsification tank with warm water, mainly the aqueous phase can be removed. At that time, cleaning performance can be improved by moving a stirrer, more preferably adding a surfactant and stirring.

After this rough washing, mainly the oil phase is washed with an organic solvent. In this case, rather than simply leaving the organic solvent still, heating the lower part and cooling the upper part will cause reflux of the solvent vapor in the emulsification tank, condensing it and removing the contaminants as it returns to the container liquid. Since the particles are taken in, the cleaning performance becomes better.

[Specific structure of the invention]

The present invention will be explained in more detail below.

Figure 1 shows the emulsification tank 1 and attached equipment.
The emulsification tank 1 is equipped with a high speed stirrer 2, for example of the Daysilver type, paddle type, propeller type or homomixer type.

For this emulsification tank, preparation tanks (not shown) for aqueous phase solution W and oil phase solution 0 as emulsified dispersions are provided, and from these tanks, aqueous phase solution W and oil phase solution 0 are prepared.
is put into the emulsification tank 1.

After the addition, emulsification and dispersion is achieved by rotating a high-speed stirrer 20 times. During this emulsification and dispersion, a heating jacket 3 is attached to the bottom of the emulsification tank 1 in order to heat or keep the liquid warm.
A cooling jacket 4 is attached to the top. L indicates an emulsified dispersion.

On the other hand, in order to remove unnecessary organic solvents such as ethyl acetate EA after completion of emulsification and dispersion, an exhaust pipe 6 provided with pressure reduction means, such as a vacuum pump 5, in the emulsification tank 1 communicates with the emulsification tank 1. 7 is an emulsion outlet and drain pipe.

As mentioned above, when cleaning the empty emulsification tank 1 after removing the emulsified dispersion and unnecessary solvents, first pour warm water into the emulsification tank 1, that is, water at a temperature higher than normal water temperature, preferably 40°C or higher. The emulsification tank 1 is filled with warm water, preferably a surfactant is added, the agitator 2 is rotated, and rough washing is performed with hot water, after which the dirty liquid is discharged from the drain pipe 7.

Then, when this rough washing is completed, an organic 8 agent, preferably the same solvent used for the oil phase solution, such as ethyl acetate (EA), is added. The amount of ethyl acetate (EA) to be added is preferably such that the liquid level is above the upper end of the heating jacket 3. In this state, the heating jacket 3 is maintained at a temperature higher than the boiling point of the organic solvent (EA) to evaporate ethyl acetate (EA), while the cooling jacket 4 above it is maintained at a temperature lower than the boiling point of ethyl acetate (EA). The temperature is maintained and the evaporated ethyl acetate (EA) vapor is condensed and refluxed to the ethyl acetate (E^) liquid. With this reflux operation, the dirt adhering to the inner surface of the emulsification tank 1 is returned to the ethyl acetate (EA) solution. by this,
The inner surface of the emulsification tank 1 is cleaned by reflux.

During this reflux cleaning, when the vacuum pump 5 is activated to reduce the pressure inside the emulsification tank 1, the evaporation of ethyl acetate (EA) is promoted, and as a result, the cleaning time is shortened.

The solvent solution contaminated during reflux cleaning is discharged from the drain pipe 7. You may finish the cleaning with the previous cleaning operations, but the solvent remaining on the inner surface of the tank 1 may dry and the dirt trapped there may come to the surface, so after reflux cleaning, immediately rinse with water, e.g. Particular preference is given to cleaning by water spray.

Instead of the above-mentioned reflux cleaning, the same cleaning performance can be obtained by storing ethyl acetate until the emulsification tank 1 is almost full and rotating the stirring a2. However, in this method, a large amount of ethyl acetate is used for each cleaning, which increases the cost. Therefore, even during reflux cleaning, it is preferable to install the heating jacket 3 as low as possible.

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 ion. 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).

The color antifogging agent used includes, for example, a hydroquinone derivative, an aminophenol derivative, a gallic acid derivative, or an ascorbic acid derivative.

Examples of the antifading agent include dihydroxyhensen derivatives, dihydroxynaphthalene derivatives, aminonaphthol derivatives, sulfonamidephenol derivatives, sulfonamidenaphthol derivatives, and the like.

The ultraviolet absorber is, for example, a hensitriazole compound substituted with an aryl group, a 4-thiazolidone compound,
A benzophenone compound, a cinnamic acid ester compound, a butadiene 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.

The organic solvent used in photographic materials is, for example, one with a high boiling point, such as phthalic acid alkyl ester, phosphoric acid ester, citric acid ester, benzoic acid ester, alkylamid, fatty acid ester, etc., with a boiling point of about 30 to 160°C.
Examples of organic solvents with relatively low boiling points include lower alkyl acetate, ethyl propionate, secondary butyl alcohol,
Examples include 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;
Cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, cellulose sulfate esters, sugar attractants such as sodium alginate, starch derivatives; polyvinyl alcohol, polyvinyl alcohol partial acetal, polyvinyl pyrrolidone, polyacrylic A wide variety of synthetic hydrophilic polymeric materials can be used, such as single or copolymers of acids, polymethacrylic acid, polyacrylamide, polyvinylimidazole, polyvinyl alcohol, and the like.

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, alkyl hanzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfates, alkyl phosphorus acid esters, N-acyl-N-alkyl taurines, sulfosuccinates, sulfoalkyl polyoxyethylene alkylphenyl ethers,
Anionic surfactants containing acidic groups such as carboxy groups, sulfo groups, phospho groups, sulfate ester groups, phosphoric ester groups such as polyoxyethylene algyl phosphates; amino acids, aminoalkyl sulfonic acids, aminoalkyl Ampholytic surfactants such as sulfuric acid or phosphoric acid esters, alkyl hetaines, amine imides, and amine oxides; heterocyclic quaternary surfactants such as alkyl amine salts, aliphatic or aromatic quaternary ammonium salts, pyridinium, and imidazolium. Cationic surfactants such as ammonium salts and phosphonium or sulfonium salts containing aliphatic or heterocycles can be used.

〔Example〕

(Example 1) In a 1001 emulsification tank, 10
% of sodium dodecylbenzenesulfonate, 6 kg of photographic gelatin, and 56 A of water were added, and while stirring in a 1801-dia. disc at 150 rpm, the following oil phase solution was added at 3.7 % (1/min) of sodium dodecylbenzenesulfonate. It was added in the liquid at an addition rate of .

(Oil phase solution) ・1-(2,46-1-lichlorophenyl)-3(3-
After adding (2,4-di-L-aminophenoxyacetamide) henzamide]-5-pyrasolone kg, tricresyl phosphate 6 kg, and ethyl acetate into the 11N solution, the rotation speed was increased to 4000 rpm, and emulsification and dispersion was performed for 50 minutes.

Thereafter, ethyl acetate was removed under reduced pressure, and the resulting emulsion was discharged from the emulsification tank.

Next, in order to clean the inside of the emulsification tank, 80° C. warm water was poured into the emulsification tank 1 and roughly washed for 10 minutes while stirring. After that, ethyl acetate from Step 51 was added instead of hot water, and the lower part was heated with 85°C hot water, and the upper part was heated at 20°C.
The mixture was cooled with cold water and washed under reflux for 60 minutes. As a result, it was able to be cleaned well without any oil or other stains.

(Example 2) The procedure was the same as in Example 1 except that the pressure was reduced to 280 Torr during reflux cleaning, and the required reflux cleaning time was shortened to 20 minutes.

(Example 3) Example 1 was the same as Example 1 except that the amount of ethyl acetate for cleaning was set at 10% above the top of the heating jacket, but the liquid level of ethyl acetate was below the top of the heating jacket. In this case, there was no trace of dirt remaining mainly from the liquid level to the upper end of the heating jacket, and extremely good cleaning performance was exhibited.

(Example 4) After the operation in Example 1, spray washing was also performed, and the solvent remaining on the inner surface of the tank 1 did not dry out, and better cleaning performance than in Example 1 was observed.

〔Effect of the invention〕

As described above, according to the present invention, not only can cleaning be performed quickly and automatically, but also the cleaning performance is extremely excellent.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an emulsification dispersion tank and attached equipment.

Claims (3)

[Claims] (1) When cleaning the emulsification tank after obtaining an oil-in-water emulsion by emulsification dispersion using an emulsification tank equipped with a stirrer; A method for cleaning an emulsification tank, which comprises washing the emulsification tank, then discharging hot water, and then pouring an organic solvent into the emulsification tank, heating the lower part and cooling the upper part to perform reflux cleaning of the solvent. (2) Claim 1: The pressure inside the emulsification tank is reduced during reflux cleaning.
The method for cleaning the emulsification tank described. (3) The method for cleaning an emulsification tank according to claim 1, wherein after the reflux cleaning, the entire inside of the tank is quickly rinsed with water.