JPH10260488A - Production of emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing an emulsified dispersion capable of stably supplying a large amt. of an oil-in water type emulsion for photographic sensitive materials which substantially hardly contains oily particles coarsened in grain sizes after emulsification dispersion. SOLUTION: An oil phase soln. is prepd. by mixing an oil-soluble component, an oily binder and a low b.p. auxiliary org. solvent and a water phase soln. is prepd. by dissolving an aq. binder in water in the process for producing the emulsified dispersion by connecting a high-speed revolutional dispersion type stirring machine 1, an on-line type emulsified dispersing machine 1, a vacuum evaporating device 14, a gas-liquid separator 17 and a condenser 21. The oil phase soln. and the water phase soln. are mixed together by the stirring machine 1, by which the oil phase soln. is emulsified and dispersed into the water phase soln. The emulsified dispersion is then fed to the dispersing machine 10 and while the diameter of dispersion phase particles in the emulsified dispersion is adjusted, the adjusted and emulsified dispersion is continuously fed online to the evaporating device 14, by which the low b.p. auxiliary org. solvent in the emulsified dispersion is selectively evaporated away.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an emulsified dispersion, and more particularly to a method for producing an oil-in-water emulsion, and more particularly, to an oil-in-water emulsion of a hydrophobic substance. The present invention relates to an improvement in a method of emulsification and dispersion during production.

[0002]

2. Description of the Related Art Oil-in-water emulsions are widely used in cosmetics, foods, paints, chemicals, etc., and are also used in photographic light-sensitive materials, pressure-sensitive papers, and the like. It is a useful ingredient in the product. Particularly in a photographic light-sensitive material, a color image forming compound (hereinafter, referred to as a “coupler”), a diffusion transfer compound, a color fogging inhibitor, a fading inhibitor,
Hydrophobic substances are used as anti-mixing agents, ultraviolet absorbers, whitening agents, etc., but adjustment of oil-in-water emulsions of these hydrophobic substances is generally carried out first if the hydrophobic substance is liquid. Or, if necessary, together with an organic solvent or with an emulsifying aid or an emulsifying aid dissolved in an organic solvent, or, when the hydrophobic substance is solid, heated or dissolved in an organic solvent, or with an emulsifying aid. Oil phase solution prepared by dissolving in an organic solvent (hereinafter simply referred to as “oil phase solution”
) Is added to an aqueous solution containing a water-soluble binder to which an emulsifying aid is added as necessary (hereinafter, simply referred to as “aqueous solution”), emulsified and dispersed, and generally 0.01 to 1.0 μm
It was prepared as an oil-in-water emulsion having an average particle size of m.

[0003] As a method for producing an emulsion according to the oil dissolving method, there are a method described in JP-A-53-112731, a method described in JP-A-61-291036, and US Pat.
No. 22027, U.S. Pat.
0 and the method described in U.S. Pat. No. 2,801,171. For example, the method described in JP-A-53-112731 is the following method using an apparatus as shown in FIG. A horizontal upper and lower table 32 is provided in the emulsifying leg 31, and an annular seal member 33 is provided on the table. A pressure reducing tank 34 having a lower end opening is provided at the upper part of the emulsifying leg 31, and a lower end of the pressure reducing tank 34 is sealed from below by a sealing member 33 at its top dead center. A storage container 35 having an upper end opening is placed in the decompression tank 34, and the outlet of the supply pipe 37 for supplying the dispersion liquid 36 is connected to the storage container 3.
It opens right above 5.

When the pressure inside the pressure reducing tank 34 is reduced by the vacuum pump 38 and the dispersion 36 is supplied from the supply pipe 37, the dispersion 3
The organic solvent mixed in 6 evaporates immediately under reduced pressure, and the heat of evaporation lowers the temperature of the dispersion 36. The liquid component in the dispersion 36 gels and falls directly into the storage container 35. If the vertically movable table 32 is lowered, the gelled emulsion can be recovered. The emulsion thus produced and recovered is immediately cooled and stored. For use, take it out of the cooling storage at any time and gradually consume it until the next production.
Excess amount should be cooled and stored each time. JP-A-61-2910
The method described in Japanese Patent Publication No. 36 is the following method using an apparatus as shown in FIG. An oil phase preparation tank 41 for preparing an oil phase solution and an aqueous phase preparation tank 42 for preparing an aqueous phase solution
And a dispersion tank 43 for dispersing the oil phase solution in the aqueous phase solution, a solvent removing device 44 for removing the organic solvent, and a dilution tank 45 in FIG.
Are connected by a liquid feed pipe 46 as shown in FIG.

[0005] An oil phase solution and an aqueous phase solution are prepared in an oil phase preparation tank 41 and an aqueous phase preparation tank 42, respectively, and the whole amount is transferred to a dispersion tank 43 to prepare a dispersion, and an emulsified dispersion is obtained. Then, the low-boiling-point organic solvent is subsequently removed by the low-boiling-point solvent removing device 44. When the concentration of the low-boiling organic solvent became lower than or equal to a predetermined value, the entire amount was collectively transferred to a dilution tank 45 and diluted by adding an aqueous phase solution from a solution supply port 47,
This is to obtain an emulsified dispersion.

[0006]

Problems to be Solved by the Invention JP-A-53-1127
In the method described in JP-A-31-31, after preparing a dispersion in which an oil phase solution is dispersed in an aqueous phase solution, the dispersion is gradually added to a supply pipe 3.
7, the emulsified dispersion stays in a state where the concentration of the low-boiling organic solvent is high until the organic solvent is volatilized in the reduced pressure tank 34. If the dispersion stays temporarily even in such a state, the dispersed phase particles gradually coalesce during that time, coalesce, and become coarse. Also in the method described in JP-A-61-291036, after the dispersion is prepared in the dispersion tank 43 and the low-boiling-point organic solvent is removed by the low-boiling-point solvent removing device 44, the coalescence of the dispersed phase particles is performed in the same manner as described above. Coarsening proceeds.

In the case of a photographic light-sensitive material, the colloid particle diameter in the emulsion must be 20 μm or less, and the size must be uniform. When an oil-in-water emulsion containing so-called oil drops having a coarse particle diameter is used, spot-like defects appear on photographic films and photographic papers. JP-A-53-11
No. 2731, JP-A-61-291036.
All of the methods described in the publications are batch-type production methods, such as the method described in U.S. Pat. No. 2,322,027, the method described in U.S. Pat.
The method described in JP-A No. 01171 is also a batch-wise production method, in which the dispersion liquid stays in the presence of a low-boiling organic solvent. There is a problem that it is practically impossible to stably obtain a large amount of emulsion for use.

Accordingly, the present invention provides a method for producing an emulsified dispersion capable of stably supplying a large amount of an oil-in-water emulsion for photographic light-sensitive materials, which hardly contains oily particles having a coarse particle size. With the goal.

[0009]

That is, the object of the present invention is achieved by the following constitutions. (1) An oil phase solution is prepared by dissolving a hydrophobic substance such as a water-insoluble coupler and / or an additive in an organic solvent together with an oily binder, and an aqueous phase solution in which an aqueous binder such as gelatin is dissolved in water and the oil phase The oil phase solution is emulsified and dispersed in the aqueous phase solution by mixing the solution with a stirrer, and the emulsified dispersion is sent to an online type continuous emulsifying and dispersing machine to continuously re-emulsify and disperse, thereby reducing the particle size. At the same time as adjusting, the emulsified dispersion was continuously sent from the on-line continuous emulsification disperser to a reduced-pressure evaporator to selectively volatilize the low-boiling organic solvent in the emulsified dispersion, and then by a gas-liquid separator. Producing an emulsion, wherein the emulsion is separated into a liquid phase component and a gas phase component of a low-boiling organic solvent, and the liquid phase component is collected from a gas-liquid separator, and the separated gas phase component is liquefied and collected. Method.

(2) When the emulsification and dispersion are performed by a high-speed rotary dispersion type stirrer, the mixture is heated to 30 ° C. to 80 ° C.
(1) characterized in that the pressure is reduced to rr to 350 torr.
3. The method for producing an emulsion according to item 1. Here, in the configuration of the above (1), a condenser is provided downstream of the gas-liquid separator, and the gas-phase component is further poured into the condenser from the gas-liquid separator to condense the low-boiling organic solvent and recover this as a liquefied component. It can be configured.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. In producing the emulsion of the present invention, an oil phase solution and an aqueous phase solution are mixed. The oil phase solution mixed with the aqueous phase solution is a mixed solution of an oil-soluble component, an oily binder, and a supplementary low-boiling organic solvent. The oil-soluble component in this case is specifically a photographic light-sensitive material, and generally contains, for example, a color image-forming compound (hereinafter referred to as "coupler"), a dye, an additive, and the like.

As the coupler which can be used in the present invention as an oil-soluble component, almost any coupler generally used as a photographic light-sensitive material can be used as long as it is oil-soluble. A coupler is a color image-forming compound that forms a dye by reacting with an oxidation product of a color developing agent such as an aromatic amine (usually a primary amine), and generally has a hydrophobic group called a ballast group in a coupler molecule. Non-diffusible ones are preferred. It may be either 4-equivalent or 2-equivalent to silver ions. The coupler includes a colored coupler having a color correcting effect, and a so-called DIR coupler which releases a development inhibitor with development. Among the couplers described above, known closed ketomethylene couplers can be used as the yellow color coupler. Of these, benzoylacetoanilide and bivaloylacetoanilide compounds are advantageous. Further, as the magenta color coupler, a birazolone compound, an indazolone compound, a cyanoacetyl compound and the like can be used, and a pyrazolone compound is particularly advantageous. Further, as the cyan coloring coupler, a phenol compound, a naphthol compound, or the like can be used. On the other hand, as the colored coupler, for example, those described in JP-A-52-42121 can be used. As the DIR coupler, for example, those described in JP-A-52-69624 can be used. Further, in addition to the DIR coupler, a compound capable of releasing a development inhibitor upon development may be contained in the photographic material. For example, those described in JP-A-53-9116 can be used. The diffusion transfer compound includes a dye developing agent diffusible dye releasing coupler (DDR coupler), a diffusible dye releasing reducing agent (DRR compound), and the like.

In addition, couplers described in the following various documents can also be used. For example, U.S. Pat. No. 2,801,170, JP-B-39-2837, and JP-A-42-239.
No. 02, Belgian Patent No. 692247, and the like. Further, the yellow forming coupler is disclosed in JP-B-42-5582, UK Patent No. * 1.
No. 13038, Belgian Patent Nos. 697112 and 701268, and the couplers and cyan-forming couplers described in JP-B-39-2
The couplers and colored couplers described in 7563 and 42-11304 are described in JP-B-42-11304, British Patent No. 1111342, Belgian Patent No. 701808, and the like. Certain couplers can be preferably mentioned.

The additives are used with or without couplers and dyes. As additives,
For example, antifoggants, fluorescent brighteners, ultraviolet absorbers, fading inhibitors and the like can be mentioned. As antifoggants, azoles such as nitroindazoles, nitroindazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles, mercaptothiadiazoles , Aminotriazoles, benzotriazoles, nitrobenzotriazoles, mercaptotetrazole (especially 1-phenyl-5-mercaptotetrazole), etc .; mercaptopyrimidines; mercaptotriazines; thioketo compounds such as oxazolinethione; , For example, triazaintenes, tetraazaintenes (especially 4-hydroxy-substituted (1,3,3a, 7) tetrazaintenes), pens Such Azainten like; benzenethiosulfonate, benzenethiosulphinic acid, and the like benzenethiosulfonate amide. Further, for example, those containing a hydroquinone derivative, an aminophenol derivative, a gallic acid derivative, or an ascorbic acid derivative can be mentioned. In addition, many compounds known as stabilizers can be added.

US Patent No. 26327 is an example of a fluorescent whitening agent.
No. 01, 3269840 and 3359
No. 102, British Patent No. 852075, ibid.
Compounds described in, for example, Japanese Patent No. 319763 can be exemplified. In addition, compounds of stilbenzene type, triazine type, oxazole type or coumarin type can also be mentioned.

There are many examples of the ultraviolet absorber. For _{example, CH 3 O-Ar-CH} = C (CN)
_{-COOCH 2 CH-C 4 H 9} -C 2 H 5, CH 3 O-
Ar-CH = C (CN) -COOC 12 H 25, CH 3 O-Ar
—CH ＝ C (CN) —COOC ₆ H ₁₃ (n), C ₅ H ₁₁ O
—Ar—CH ＝ C (CN) —COOC ₆ H ₁₃ (n) and the like. In the formula, Ar represents a benzene ring. Further, as an ultraviolet absorber, for example, a benzotriazole compound substituted with an aryl group, a 4-thiazolidone compound, a benzophenone compound, a cinnamate compound,
Examples thereof include a butadiene compound and a benzooxyzole compound, and examples thereof include an ultraviolet absorbing coupler and an ultraviolet absorbing polymer.

Examples of the anti-fading agent include dihydroxybenzene derivatives, dihydroxynaphthalene derivatives, aminonaphthol derivatives, sulfonamidophenol derivatives, sulfonamidonaphthol derivatives and the like.

In the oil phase solution, an oily binder is used together with such oil-soluble components. Examples of the oily binder include alkyl phthalate, phosphate, citrate, benzoate, alkyl amide, fatty acid ester, lower alkyl acetate, and ethyl propionate. These may be used in combination. A low-boiling organic solvent is further used in the oil phase solution together with these oily binders. As a low boiling point organic solvent,
The following examples can be given. That is, alcohols such as methanol and ethanol; acetates such as ethyl acetate, methyl acetate and butyl acetate; saturated and unsaturated aliphatic hydrocarbons such as M-hexane; and aromatic hydrocarbons such as benzene, toluene and xylene. , Cyclopentane, alicyclic hydrocarbons such as cyclohexane, chloroform, halogenated hydrocarbons such as dichloromethane, phenols such as phenol, cresol, dibutyl ether, tetrahydrofuran, ethers such as dioxane,
Ketones such as acetone and cyclohexanone; fatty acids such as acetic acid and propionic acid; acid anhydrides such as acetic anhydride and propionic anhydride; nitrogen compounds such as nitromethane, acetonitrile, pyridine and N, N-dimethylformamide;
In addition to sulfur compounds such as carbon disulfide and dimethyl sulfoxide, diethylene glycol, diethylene glycol monomethyl ether and the like can be mentioned. In addition, lower alkyl acetate, ethyl propionate, secondary butyl alcohol, methyl isobutyl ketone, cyclohexanone, β-ethoxyethyl acetate, methyl cellosolve acetate and the like can be mentioned. These may be used alone or in combination. Among them, ethyl acetate is preferred as the low boiling point organic solvent.

In the present invention, an aqueous phase solution is used together with an oil phase solution. The aqueous phase solution is obtained by dissolving an aqueous binder in water. The aqueous binder is a water-soluble polymer compound, and examples thereof include the following examples. That is,
Gelatin, gelatin derivatives, kraft polymers of gelatin and other polymers can be mentioned, carboxymethylcellulose, cellulose sulfates, cellulose derivatives such as hydroxyethylcellulose, polyvinyl alcohol, polyvinyl alcohol partial acetal, poly -N-vinylhydrin, polyacrylic acid, polymethacrylic acid copolymer, polyacrylamide, polyvinylimidazole, polyvinylpyrazole and the like can include various kinds of synthetic hydrophilic polymer compounds such as a single or copolymer, such as albumin, Examples include proteins such as casein, and sugar derivatives such as sodium alginate and starch derivatives. Furthermore, these partial hydrolysates can also be mentioned. These may be used alone or in combination. Among them, gelatin is most preferred.

The method for producing an emulsion of the present invention is carried out using the following apparatus for producing an emulsion. FIG. 1 is an example of a system diagram of an emulsion production apparatus that can be used in the present invention. Embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the emulsification dispersion tank 3 is formed by a configuration in which a stirrer 1 is provided in a tank 2 provided with a temperature control running water jacket 2a. Emulsification dispersion tank 3
Has injection ports 31 and 32 at the upper part of the emulsification and dispersion tank 3 together with the vacuum pump 4, and has an aqueous phase solution preparation tank 6 and an oil phase solution preparation tank 7 above.

The emulsification / dispersion tank 3 is a closed type, high-speed rotation-type emulsification / dispersion apparatus, in which a high-speed rotation stirrer 1 is installed. An example of this high-speed rotation stirrer is disclosed in JP-A-57-59620. The device described in the specification can be applied. A first dispersion pipe 9 provided with a gate valve 8 extends from a lower discharge port of the emulsification / dispersion tank 3 and reaches an inlet of an online type continuous emulsification / dispersion machine 10. As the online type continuous emulsification, a high-pressure homogenizer, a colloid mill, a milder, a microfluidizer, and the like can be used.

A second dispersion pipe 13 having a back pressure valve 12 extends from a discharge port of the online type continuous emulsification and dispersion machine 10 to a heating and decompression evaporator 14. As this heating and decompression evaporating apparatus, a double vertical tube or a plate heat exchanger type can be used. In this embodiment, a double vertical tube is shown as a specific example. The heating and decompression evaporator 14 has a volatilizing tube 15 directly connected to the second dispersion tube 13 and has a temperature of 40 ° C.
A hot water pipe 16 for passing hot water of 80 ° C. surrounds the hot water pipe 16 to form a double pipe structure. The heating and decompression evaporator 14 has a discharge port of the volatilization tube 15 opened in the gas-liquid separator 17.

The gas-liquid separator 17 has a liquid level sensor 17a at the bottom, is stored in a jacket, and a discharge pipe 18 provided at the bottom is connected to a discharge pump 19. A gas-phase tube 20 extends from inside the gas-liquid separator 17 and is connected to a condenser 21. The condenser 21 is provided with a communicating pipe 22 for cold water.
The low-boiling organic solvent introduced therein comes into contact with the communication tube 22. Further, a drain 23 is provided at the bottom of the condenser 21, leading to a receiver 24. A water-sealed vacuum pump 25 is provided above the condenser 21.

In the method for producing an emulsion of the present invention, for example, an emulsion may be produced using such an emulsion production apparatus as follows. An oil-soluble component, an oil-based binder, and a low-boiling organic solvent are mixed in a predetermined ratio in an oil-phase solution preparation tank to prepare an oil-phase solution. The aqueous binder, water, and the emulsification aid are charged into the emulsification / dispersion tank 3 and mixed by rotating the stirrer 1 to prepare an aqueous phase solution in the emulsification / dispersion tank 3 or a separately installed aqueous phase solution. It may be prepared in the preparation tank 6.

After the oil phase solution is dispersed in the aqueous phase solution, the tank bottom valve 8b is opened, and the emulsified dispersion is sent to the online type continuous emulsifying and dispersing machine 10 to adjust the particle size of the re-emulsified dispersed phase.
At this time, the emulsified dispersion is heated to 30 ° C. to 80 ° C. inside the high-speed rotation dispersion type stirrer 10.

The vacuum pump 25 is driven to reduce the pressure in the heating and decompression evaporator 14, the gas-liquid separator 17, and the condenser 21, while hot water is passed through the hot water pipe 16. Subsequently, the heating type reduced pressure evaporator 14
Of the dispersion liquid in the volatilization tube 15 having an average flow rate of 0.5 to 3 m / se.
c, preferably 1 to 1.5 m / sec. In the volatilization tube 15, the temperature is raised to 40 ° C. to 80 ° C., and the pressure is reduced to 15 torr to 350 torr. Thereby, the low-boiling organic solvent in the dispersion is selectively evaporated and led to the gas-liquid separator 17.

The emulsified dispersion component flows into the gas-liquid separator 17 at a temperature of usually 25 ° C. to 45 ° C., and is separated into a gaseous phase and a liquid phase. The liquid phase in which the low boiling point organic solvent has volatilized is driven by the liquid level sensor 26 to drive the tank bottom valve 8b, the valve 8c, and the extraction pump 19, and the liquid is circulated from the discharge pipe 18 to the circulation system pipe 8b, and then sent to the pipe 18a. After filling with the liquid, the valve 8c is closed, and at the same time, the valve 8d is opened to collect and store. The volatilized low-boiling organic solvent is poured into the condenser 21 to be liquefied again, and collected in the receiver 24.

[0028]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples. [Example] Cyan coupler as an oil-soluble component was 24.5.
Kg, 14.5 kg of ultraviolet absorber, 42 g of tricresyl phosphate as an oily binder, 45.5 l of ethyl acetate as a low boiling organic solvent, 35 kg of gelatin as an aqueous binder, 310 l of water, and dozil as a surfactant as an emulsifying aid. Using 20 l of a 10% solution of benzenesulfonic acid, an oil-in-water emulsion was continuously produced according to the above embodiment. Less coarse particles, 0.1μm diameter
The following uniform fine emulsion was obtained. The number of coarse particles having a diameter of 20 to 60 μm was 10 or less in 1 cc. In the embodiment, the required amount can be easily produced each time, and the production and storage is not required. Therefore, a cooling storage device is not required. Further, the used equipment can be washed with the recovered low-boiling organic solvent, and the economic efficiency has been improved.

[0029]

According to the present invention, while controlling the particle size of the emulsified dispersion phase, the emulsified dispersion is continuously sent to the reduced-pressure evaporator online, and the low-boiling auxiliary organic solvent in the emulsified dispersion is removed. An oil-in-water emulsion for photographic light-sensitive materials, in which the low-boiling auxiliary organic solvent does not stay in the emulsified dispersion at a high concentration and contains virtually no coarse particles, since it is immediately volatilized and selectively removed. Goods can be supplied stably in large quantities.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a system diagram of an emulsion production apparatus used in the present invention.

FIG. 2 is a system diagram showing an example of a conventional emulsion production apparatus.

FIG. 3 is a system diagram showing another example of a conventional emulsion production apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stirrer 3 Emulsion dispersion tank 10 Online-type emulsification dispersion machine 14 Heating decompression evaporator 17 Gas-liquid separator 21 Condenser 25 Vacuum pump

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Takeshi Wada 210 Nakanakanuma, Minamiashigara, Kanagawa Prefecture Fuji Photo Film Co., Ltd.

Claims (2)

[Claims] 1. An oil phase solution in which a hydrophobic substance such as a water-insoluble coupler and / or an additive is dissolved in an organic solvent together with an oily binder, and an aqueous phase solution in which an aqueous binder such as gelatin is dissolved in water is prepared. The oil phase solution is mixed with a stirrer to emulsify and disperse the oil phase solution in the aqueous phase solution, and the emulsified dispersion is sent to an online type continuous emulsifying and dispersing machine to continuously perform re-emulsification and dispersion. While adjusting the diameter, simultaneously, the emulsified dispersion is continuously sent from an online type continuous emulsification disperser to a reduced-pressure evaporator to selectively volatilize a low-boiling organic solvent in the emulsified dispersion, and then perform gas-liquid separation. An emulsion wherein the liquid phase component is separated into a gas phase component of a low-boiling organic solvent by a vessel, and the liquid phase component is recovered from the gas-liquid separator, and the separated gas phase component is liquefied and recovered. Manufacturing method. 2. When the emulsification and dispersion are carried out by a high-speed rotary dispersion type stirrer, the mixture is heated to 30 ° C. to 80 ° C., and the reduced pressure evaporator is heated to 40 ° C. to 80 ° C. and 15 torr.
The method for producing an emulsion according to claim 1, wherein the pressure is reduced to 350 torr.