JP2003192706A - Method for producing oil-in-water dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an oil-in-water dispersion which is independent of changes in flow rate or a hydrophobic liquid and properties of an aqueous medium and allows hydrophobic liquid drops having a stable and uniform particle diameter to disperse in a wide range of flow rate of the hydrophobic liquid. <P>SOLUTION: The method for producing an oil-in-water dispersion comprises jetting a hydrophobic liquid 13 immiscible with the aqueous medium 11 through a nozzle member 17 having a jetting hole 16 into the continuous phase of the aqueous medium 11 forming a continuous phase to disperse the hydrophobic liquid drops 26 formed of the hydrophobic liquid 13 in the aqueous medium 11, wherein the aqueous medium is controlled to have a temperature of 30-90°C. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an oil-in-water type dispersion in which hydrophobic droplets are dispersed in an aqueous medium, and more specifically, it is suitable for producing resin particles having a uniform particle size. The present invention relates to a method for producing an oil-in-water type dispersion liquid in which hydrophobic droplets having a uniform particle size are dispersed.

[0002]

2. Description of the Related Art Conventionally, in the case of producing a granular resin, for example, in the case of producing particles of a styrene-divinylbenzene copolymer which has been used as a base bead of an ion exchange resin for a long time, it is usually conducted in an aqueous medium. A suspension polymerization method in which a hydrophobic monomer-containing liquid is dispersed and polymerized is used. In this method, the particle size of the polymer particles to be obtained depends on the particle size of the hydrophobic droplets in the aqueous medium, but the particle diameters of the monomer-containing droplets dispersed in water by the usual method vary. Therefore, there is a problem in that the particle size of the polymer particles obtained by the polymerization also varies. Therefore, prior to the polymerization, a method has been proposed in which an oil-in-water type dispersion liquid in which monomer-containing droplets having a uniform particle size are dispersed is produced by another apparatus, and the dispersion liquid is charged into a polymerization container to perform polymerization. . As a method for producing an oil-in-water type dispersion having a uniform particle size, a nozzle plate with upwardly formed ejection holes is provided at the bottom of a container filled with water, and the monomer-containing liquid is supplied into water through the ejection holes. To disperse the monomer-containing droplets in water (Japanese Patent Application Laid-Open No. 49-5578).
No. 2) exists. In order to carry out this method industrially, it is necessary to provide a large number of ejection holes to continuously and efficiently generate the monomer-containing droplets. However, when the number of ejection holes is small, there is no problem, but when the number of ejection holes increases and the density becomes high, the discharge flow of the monomer-containing liquid discharged near the ejection holes in the center of the nozzle plate fluctuates left and right. Therefore, it is difficult to make the monomer-containing liquid discharged into water from each ejection hole into a droplet in a constant state, and it becomes impossible to form a monomer-containing droplet having a uniform particle diameter.

As a method for solving this, Japanese Patent Laid-Open No. 3-2
Japanese Patent Publication No. 49931 proposes a method of adopting a nozzle plate in which the ejection holes are annularly arranged around the periphery of the nozzle plate, except for the central portion, instead of uniformly providing the ejection holes on the entire surface of the nozzle plate. By arranging the ejection holes in this way, even if the density of the ejection holes is increased, it is possible to suppress the left and right fluctuations of the discharge flow of the monomer-containing liquid in the vicinity of the ejection holes, and increase the number of ejection holes. It is also possible to produce monomer-containing droplets having a uniform particle size. Further, conventionally, the temperature and flow rate of the monomer-containing liquid when the monomer-containing droplets having a uniform particle size are obtained largely depend on the physical properties of the aqueous medium and the monomer-containing liquid, particularly the specific gravity, the viscosity, and the interfacial tension. I know that. Then, in the control of the operating conditions so far, the temperature of the aqueous medium and the temperature of the hydrophobic liquid have been set to the same temperature. This is a method of generating a monomer-containing droplet by ejecting a monomer-containing liquid into an aqueous medium,
It is considered that the temperature of the monomer-containing liquid becomes the same temperature as that of the aqueous medium at the moment of jetting, and that the temperature of the interface, which is considered to have the greatest influence on the formation of the monomer-containing droplets, also becomes the same as the temperature of the aqueous medium instantaneously. Because it was thought.

[0004]

However, according to the method employing the nozzle plate in which the ejection holes are annularly arranged around the periphery thereof except for the central portion, hydrophobic droplets (monomer-containing droplets) having a uniform particle diameter are used. However, in order to obtain efficiently and stably, the flow rate of the hydrophobic liquid (monomer-containing liquid) and the aqueous medium is finely controlled according to the temperature, specific gravity, viscosity, etc. Had to do. Therefore, when manufacturing the same product for a long period of time, there is no big problem, but when manufacturing many brands while frequently switching with the same equipment, such as ion-exchange resin matrix beads, when switching between brands Loss, that is, a large amount of product variation is lost when the flow rate of the switched hydrophobic droplets of the changed brand changes at the start and stop of production. Therefore, controlling the flow rate of the hydrophobic liquid from the ejection holes of the nozzle plate itself has been a major factor in reducing the production efficiency of the hydrophobic droplets. The present invention has been made in view of the above circumstances, and is less affected by changes in the flow rate and physical properties of the hydrophobic liquid and physical properties of the aqueous medium, and has a stable and uniform particle size in a wide flow range of the hydrophobic liquid. An object of the present invention is to provide a method for producing an oil-in-water type dispersion liquid in which hydrophobic droplets are dispersed.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies in order to solve the above problems, and individually control the temperatures of an aqueous medium and a hydrophobic liquid to obtain a uniform particle size in a wide flow rate range. It has been found that a droplet having the above can be obtained, and the method for producing an oil-in-water dispersion of the present invention has been completed. The method for producing an oil-in-water dispersion according to the present invention in accordance with the above object,
A hydrophobic liquid that is immiscible with the aqueous medium is ejected into the aqueous medium forming the continuous phase through a nozzle member having ejection holes to form a hydrophobic liquid in the aqueous medium. In the method for producing an oil-in-water dispersion liquid in which drops are dispersed, the temperature of the aqueous medium is 30 to 90 ° C.
Control to the range of.

Generally, in the production of hydrophobic droplets, it is premised that the produced hydrophobic droplets are subjected to processing such as some operation or reaction. However, the processing conditions are often different from the manufacturing conditions for the hydrophobic droplets. For example, when either or both of the hydrophobic liquid and the aqueous medium have reactivity, the conditions necessary for promoting or suppressing the reaction and stable and highly uniform particle size The operating conditions of the device for obtaining hydrophobic droplets are often different. In that case, the safety and stability of the entire manufacturing process are increased by giving priority to whichever is controlled. A confirmation experiment was conducted in which the aqueous medium and the hydrophobic liquid were kept at different temperatures, and the hydrophobic liquid was discharged from the ejection holes into the aqueous medium to form hydrophobic droplets. It has been found that hydrophobic liquids form hydrophobic droplets before their temperature becomes the same as that of the aqueous medium. This indicates that even if the aqueous medium and the hydrophobic liquid are held at different temperatures, there is no hindrance to the formation of the hydrophobic droplets. Therefore, the characteristics of the hydrophobic liquid may change due to reaction during storage, and the temperature of the hydrophobic liquid needs to be stored at a temperature defined according to the property of the hydrophobic liquid. It has been shown that the temperature of the aqueous medium whose properties do not change can be set to any temperature, for example the optimum temperature for forming hydrophobic droplets. Therefore, it was decided to control the temperature of the aqueous medium to the optimum temperature for forming hydrophobic droplets, which is 30 to 90 ° C.

In the method for producing an oil-in-water type dispersion according to the present invention, the hydrophobic liquid may be a polymerizable monomer. When the hydrophobic liquid is a polymerizable monomer, the obtained hydrophobic droplets can be easily polymerized.

In the method for producing an oil-in-water dispersion according to the present invention, the temperature of the hydrophobic liquid is set to be 1 temperature higher than the polymerization initiation temperature.
It is preferable to control the temperature to be lower than 5 ° C. When the hydrophobic liquid is a polymerizable monomer, the polymerization reaction may proceed even during storage. In order to stably produce hydrophobic droplets having a uniform particle size, it is necessary to suppress the polymerization of the stored hydrophobic liquid during the production period of the hydrophobic droplets, and during that period, For example, about one day is required. Therefore, when the hydrophobic liquid is stored for one day, the temperature at which the polymerization reaction proceeds and the properties of the hydrophobic liquid change clearly,
It is defined as the polymerization initiation temperature. Then, a detailed confirmation experiment was conducted under the condition that the hydrophobic liquid could be polymerized, and if the hydrophobic liquid was kept at a temperature lower than the polymerization initiation temperature by 15 ° C. or more, it could be stored for about one day. It has been found that it is possible to prevent the initiation of the polymerization reaction during. Therefore, it was decided to control the temperature of the hydrophobic liquid at a temperature lower than the polymerization initiation temperature by 15 ° C. or more.

In the method for producing an oil-in-water dispersion according to the present invention, the difference between the temperature of the aqueous medium and the polymerization initiation temperature is 1
It is preferable to control the temperature within 5 ° C. Considering mainly to suppress the polymerization of the stored hydrophobic liquid, the temperature of the hydrophobic liquid needs to be controlled below the polymerization initiation temperature.
However, the polymerization initiation temperature is considerably lower than the optimum temperature of the aqueous medium for forming hydrophobic droplets having a uniform particle size. For this reason, if the hydrophobic liquid is kept below the polymerization initiation temperature to form the hydrophobic droplets, the temperature difference between the hydrophobic liquid and the aqueous medium becomes too large, and the resulting hydrophobic droplets have a uniform particle size. The sex is very low. Therefore, a detailed experiment on the formation of hydrophobic droplets was carried out. When the temperature of the aqueous medium was controlled so that the temperature difference between the temperature of the aqueous medium and the polymerization initiation temperature was within 15 ° C. (for example, , If the temperature of the aqueous medium is controlled to 30 ° C or higher),
It was confirmed that the uniformity of the droplet diameter obtained at this time was dramatically improved. Therefore, it was decided to control the difference between the temperature of the aqueous medium and the polymerization initiation temperature of the hydrophobic liquid within 15 ° C.

In the method for producing an oil-in-water type dispersion according to the present invention, it is preferable to control the temperature of the hydrophobic liquid to 30 ° C. or lower. A detailed experiment for determining the polymerization initiation temperature of the monomer revealed that the polymerization initiation temperature exceeded 30 ° C. Therefore, it was decided to control the temperature for storing the hydrophobic liquid to 30 ° C. or lower. This can prevent the hydrophobic liquid from polymerizing during the production of the hydrophobic droplets.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is a side sectional view schematically showing an apparatus for producing an oil-in-water dispersion liquid to which a method for producing an oil-in-water dispersion liquid according to an embodiment of the present invention is applied, and FIG. FIG. 3 is a plan view of a nozzle member provided in the dispersion liquid manufacturing apparatus, and FIG. 3 is a side sectional view showing a modified example of the oil-in-water dispersion liquid manufacturing apparatus. As shown in FIG. 1, an apparatus 10 for producing an oil-in-water dispersion according to an embodiment of the present invention includes a hydrophobic droplet production tank 12 that stores an aqueous medium 11 that forms a continuous phase, and an aqueous medium 11. A hydrophobic liquid storage tank 14 that stores a hydrophobic liquid 13 that is immiscible with the hydrophobic liquid storage tank 14, and a hydrophobic liquid manufacturing tank 12 that stores the hydrophobic liquid 13 stored in the hydrophobic liquid storage tank 14.
And a hydrophobic liquid supply pipe 15 which is an example of a hydrophobic liquid supply means for supplying the Further, the apparatus 10 for producing an oil-in-water type dispersion liquid has a nozzle member 17 which is in contact with the aqueous medium 11 and has ejection holes 16 for ejecting the hydrophobic liquid 13 supplied from the hydrophobic liquid supply pipe 15, and an aqueous solution. An aqueous medium storage tank 18 for storing the medium 11 and an aqueous medium supply pipe 19 which is an example of an aqueous medium supply means for supplying the aqueous medium 11 stored in the aqueous medium storage tank 18 to the hydrophobic droplet production tank 12 are provided. ing. Here, reference numeral 20 is a hydrophobic liquid ejection storage tank,
Reference numerals 21 and 22 denote the hydrophobic liquid 13 and the aqueous medium 1, respectively.
1 shows a feed pump of 1. Reference numerals 23 and 24 denote heaters provided on the hydrophobic liquid supply pipe 15 and the aqueous medium supply pipe 19, respectively.

With such a structure, the hydrophobic liquid 13 stored in the hydrophobic liquid storage tank 14 is transported by the supply pump 21 through the hydrophobic liquid supply pipe 15 and is heated by the heater 23 in a predetermined manner. It can be heated to a temperature and supplied into the hydrophobic liquid ejection storage tank 20. Further, the hydrophobic liquid 13 having a predetermined temperature supplied into the hydrophobic liquid jet storage tank 20 is held in the hydrophobic liquid droplet production tank 12 through the jet holes 16 provided in the nozzle member 17 to form a continuous phase. Medium 11
A jet flow of the hydrophobic liquid 13 can be formed by jetting into the inside. On the other hand, the aqueous medium 11 stored in the aqueous medium storage tank 18 is transported by the supply pump 22 via the aqueous medium supply pipe 19 and heated to a predetermined temperature by the heater 24,
By supplying from the aqueous medium jetting part 25 into the hydrophobic liquid droplet production tank 12, a flow of the aqueous medium 11 from the lower part to the upper part can be formed in the hydrophobic liquid droplet production tank 12.
The generated hydrophobic droplets 26 can be moved by this flow.

A hydrophobic liquid jetting storage tank 20 is present in the lower inner portion of the hydrophobic liquid droplet production tank 12, and a jetting hole 16 is opened in the upper portion thereof toward the aqueous medium 11 to jet the hydrophobic liquid 13. Is provided with a nozzle member 17. Therefore, from the hydrophobic liquid storage tank 14 to the hydrophobic liquid supply pipe 15
The heated hydrophobic liquid 13 supplied by the supply pump 21 via the is stored in the hydrophobic liquid ejection storage tank 20 and ejected straight upward from the ejection holes 16 provided in the nozzle member 17. It As shown in FIG. 2, the nozzle member 17 has, for example, a disk shape, and the annular region having a radius A to a radius B (A <B) penetrates from one surface to the other surface and is hydrophobic. A plurality of ejection holes 16 for ejecting the liquid 13 are arranged with a predetermined interval, for example, an interval of 2 mm or more. Further, the diameter of the ejection hole 16 can be properly used depending on the desired droplet size, and the ejection hole diameter is, for example, 20 to 500 μm.

For example, when the hydrophobic liquid 13 controlled to 30 ° C. or less is jetted toward the inside of the aqueous medium 11 from the jet holes 16 provided in the nozzle member 17, the temperature of the aqueous medium 11 is, for example, 30 to 90 ° C. By holding at, the hydrophobic droplets 26 having a uniform particle size can be easily formed.
Further, since the temperature of the aqueous medium 11 is maintained at 30 to 90 ° C., the hydrophobic droplets may be gradually heated while floating in the aqueous medium 11 and partially start the polymerization. It is possible to minimize coalescence and destruction of the hydrophobic droplets 26. As a result, the oil-in-water type dispersion liquid in which the hydrophobic droplets 26 having a uniform particle size are dispersed in the aqueous medium 11 can be stably manufactured. The produced oil-in-water dispersion liquid is transferred from the oil-in-water dispersion liquid outlet 27 to a polymerization tank via a transport pipe (not shown).

Next, the method for producing the oil-in-water type dispersion according to one embodiment of the present invention will be described in detail. Injecting holes 16 into an aqueous medium 11 (for example, an aqueous phase) forming a continuous phase
When the hydrophobic liquid 13 (for example, the oil phase) is supplied through the liquid jet, a liquid column-shaped jet flow is formed, and the droplet is divided into hydrophobic droplets 26 on the tip side of the jet flow. In this case, water is usually used as the aqueous medium 11, but if necessary, the aqueous medium 11 may be
Various additives composed of water-soluble compounds such as inorganic acid salts and water-soluble polymers may be added. On the other hand, the hydrophobic liquid 13 needs to be a liquid that is not compatible with the aqueous medium 11 and can form droplets in the aqueous medium 11. The components of the hydrophobic liquid 13 can be appropriately selected according to the purpose. For example, in the case of producing the hydrophobic droplets 26 used in the suspension polymerization for producing the granular resin, the monomer is used as the hydrophobic liquid 13 as it is, or a solvent immiscible with water is used as necessary. It can also be used in the form of a monomer solution dissolved in. The hydrophobic liquid 13 needs to contain a polymerization initiator in the case of a vinyl monomer, for example.

The hydrophobic liquid 13 is not particularly limited as a polymerizable monomer, and any one can be used as long as it can be used for suspension polymerization. For example, styrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, p-methoxystyrene, p
-Phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-
Butyl styrene, pn-hexyl styrene, pn-
Octyl styrene, pn-nonyl styrene, pn-
Styrene and its derivatives such as decylstyrene, polyvinyl aromatic compounds such as divinylbenzenedivinyltoluene, divinylxylene and trivinylbenzene, vinyl acetates, vinyl propionate, vinyl benzoate and other organic acid vinyl esters, methacrylic acid and methacrylic acid. Methyl,
Ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, dimethylaminomethyl methacrylate, etc. Methacrylic acid and its derivatives, acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, stearyl acrylate, phenyl acrylate, etc. Acrylic acid and its derivatives, vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone, N-vinyl pyrrole, N
-N-, such as vinylcarbazole and N-vinylpyrrolidone
Polymerizable monomers such as vinyl compounds, vinylnaphthalene, acrylonitrile, methacrylonitrile, and acrylamide can be used. These monomers can be used alone or in combination of two or more kinds in various compositions, if necessary.

As the polymerization initiator, a radical polymerization initiator conventionally used for producing a polymer from the above-mentioned monomers can be used. For example, a monomer-soluble radical polymerization initiator such as peroxide, for example, benzoyl peroxide or azobisisobutyronitrile, or a water-soluble radical polymerization initiator, for example, persulfate,
Hydrogen peroxide or hydroperoxide is used. The hydrophobic liquid 13 is composed of one kind or a combination of two or more kinds of monomers and a radical polymerization initiator. The physical properties (viscosity, specific gravity,
The interfacial tension) is very different. Therefore, the hydrophobic liquid 13
Specific gravity of 0.8 or more and 1.4 or less, and a viscosity of 0.
It is preferably adjusted to 1 cps (centipoise) or more and 200 cps or less. When the hydrophobic droplets 26 are suspended in the aqueous medium 11, the difference between the specific gravity of the aqueous medium 11 and the specific gravity of the hydrophobic droplets 26 (specific gravity of the aqueous medium −
The specific gravity of the hydrophobic droplet 24 is preferably 0 to 0.5.

The aqueous medium 11 used in the continuous phase is immiscible with the hydrophobic liquid 13 (eg monomer) and
It must be a suitable inert liquid in which the hydrophobic liquid 13 can be dispersed as droplets therein. Usually an aqueous medium 1
1 includes a suspending agent. The suspending agents which can be used in a conventional manner depend on the type, composition and amount of the hydrophobic liquid 13 used. The suspending agent used here is not particularly limited, and may be a suspending agent used in ordinary suspension polymerization. Typically, gelatin, polyvinyl alcohol, starch,
Polyacrylamides, water-inert inorganic compounds such as magnesium silicate, and cellulose ethers such as carboxymethyl-methylcellulose. However,
In order to maintain the uniformity of the particle size without coalescing and crushing the generated hydrophobic droplets 26, the type of the aqueous medium 11 and the concentration of the suspending agent are determined by the correlation with the physical properties of the hydrophobic liquid 13. decide. In order to maintain the uniformity of the particle size of the hydrophobic droplets 26, the suspending agent is 0.0 to the total weight of the aqueous medium 11.
It is 1 to 5% by weight, preferably 0.05 to 1.5% by weight.

In the production of oil-in-water dispersions, hydrophobic droplets 2
It is premised that the polymerization treatment is performed after the formation of No. 6. However, the conditions of the polymerization treatment are as follows:
Is different from the forming conditions of. Here, when manufacturing is performed in the direction of increasing the safety and stability of the entire manufacturing process, the hydrophobic droplets 26 are prioritized under the condition of obtaining the hydrophobic droplets 26 having a stable and high particle size uniformity. Need to be manufactured. For this reason, the temperature of the hydrophobic liquid 13 that may change in characteristics due to reaction or the like during storage needs to be stored at a temperature lower than the polymerization initiation temperature defined according to the property of the hydrophobic liquid 13. The temperature of the aqueous medium 11 whose characteristics do not change due to reaction or the like during storage can be maintained at the optimum temperature for forming the hydrophobic droplets 26. Therefore, the aqueous medium 11
Control the temperature between 30 and 90 ° C. Further, in order to stably produce the hydrophobic droplets 26 having a uniform particle size, the hydrophobic liquid 13 stored during the production period of the hydrophobic droplets 26 (for example, about one day) is polymerized. To prevent the characteristics from changing. Therefore, the hydrophobic liquid 13
Is stored at a temperature lower than the polymerization initiation temperature by 15 ° C. or more (for example, a temperature of 30 ° C. or less). Further, it is necessary to dramatically improve the uniformity of the particle size of the obtained droplets. Therefore, the temperature difference between the temperature of the aqueous medium 11 and the polymerization initiation temperature is controlled to be within 15 ° C.

FIG. 3 shows an apparatus 10 for producing an oil-in-water type dispersion liquid.
The manufacturing apparatus 28 of the oil-in-water type dispersion which is a modification of this is shown.
The oil-in-water type dispersion manufacturing apparatus 28 includes a hydrophobic droplet manufacturing tank 29 for storing the aqueous medium 11 forming a continuous phase, and ejection holes 30 for ejecting the hydrophobic liquid 13 supplied in contact with the aqueous medium 11. It has a nozzle member 32 having a blow-in portion 31 provided with. Hereinafter, these will be described in detail, but the substantially same components as those in the oil-in-water dispersion manufacturing apparatus 10 according to the present embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In the apparatus 28 for producing an oil-in-water dispersion liquid, a single blowing part 31 is provided so as to penetrate from the outer side to the inner side of the hydrophobic droplet manufacturing tank 29 in the central part of the nozzle member 32. One ejection hole 30 is provided in the central portion. Further, the opening of the aqueous medium jetting part 25 of the aqueous medium supply pipe 19 for supplying the aqueous medium 11 into the hydrophobic droplet production tank 29 is provided at the lower part of the side wall of the hydrophobic droplet production tank 29.

The hydrophobic liquid 13 jetted from the jet holes 30
Since there is only one jet of water, the generated flow of the hydrophobic droplets 26 is also one. Therefore, the inner diameter of the hydrophobic droplet manufacturing tank 29 can be reduced. Therefore, by providing the opening of the aqueous medium jetting portion 25 for supplying the aqueous medium 11 into the hydrophobic liquid droplet production tank 29 at the lower part of the side wall of the hydrophobic liquid droplet production tank 29, the aqueous medium 11 directed upward from the lower part A stream can be formed and the hydrophobic droplets 26 generated by this stream can be displaced. The method for producing an oil-in-water dispersion using the oil-in-water dispersion production apparatus 28 is the same as the method for producing an oil-in-water dispersion when the oil-in-water dispersion production apparatus 10 is applied. be able to. Therefore, the description of the method for producing the oil-in-water dispersion liquid to which the apparatus 28 for producing the oil-in-water dispersion liquid is applied is omitted.

[0022]

EXAMPLES Example 1 Using the oil-in-water type dispersion production apparatus 10 shown in FIG. 1, hydrophobic droplets 26 having a uniform particle size were produced. Here, an apparatus 10 for producing an oil-in-water dispersion liquid
Has an inner diameter of 0.3 m and a height of 0.4 m. As shown in FIG. 2, the nozzle member 17 provided in the hydrophobic droplet manufacturing tank 12 is provided.
Is a disc with an outer diameter of 100 mm and a radius of 35 mm to 45 mm
In the range of, the ejection holes 16 having a diameter of 0.15 mm have a hole interval of 2
There are 345 mm units. Hydrophobic droplet manufacturing tank 12
Is kept at 25 ° C., and an aqueous solution containing 0.05% of polyvinyl alcohol (aqueous medium 11) is stored in the aqueous medium storage tank 18
Is supplied to the heater 24 through the aqueous medium supply pipe 19, heated to 30 ° C., and filled in the hydrophobic droplet manufacturing tank 12. Furthermore, the flow rate of the polyvinyl alcohol aqueous solution is 800 cc / m
In, the water is supplied from the aqueous medium storage tank 18 to the heater 24 via the aqueous medium supply pipe 19, heated to 30 ° C., and supplied to the hydrophobic droplet manufacturing tank 12. The aqueous medium supply pipe 19 has an inner diameter of 1
It is 5 mm, and the opening of the aqueous medium jetting part 25 is provided facing the center of the nozzle member 17 with a distance of 5 mm from the upper surface of the nozzle member 17.

Then, the styrene monomer simple substance (hydrophobic liquid 13) stored in the hydrophobic liquid storage tank 14 is supplied to the heater 23 through the hydrophobic liquid supply pipe 15 and heated to 25 ° C. to make it hydrophobic. It is supplied to the liquid jet storage tank 20, and the flow rate is 1.2 to 1.4 cc / mi from the jet hole 16 of the nozzle member 17.
It is jetted into the polyvinyl alcohol aqueous solution in the hydrophobic droplet manufacturing tank 12 at n / hole. An oil-in-water type dispersion liquid in which styrene monomer droplets (hydrophobic droplets 26) are dispersed in the hydrophobic droplet manufacturing tank 12 is produced by continuously forming droplets of a styrene monomer simple substance in an aqueous polyvinyl alcohol solution. To do. The obtained oil-in-water dispersion was collected from the oil-in-water dispersion outlet 27. The average diameter of the styrene monomer droplets obtained at this time was 0.429 mm, and the average diameter ±
The flow rate range of the styrene monomer in which 80% or more of the styrene monomer droplets contained in the range of 10% is 1.28 to 1.31 cc / min / hole is 0.03.
It was confirmed that there was cc / min / hole width. Moreover, the maximum value of the volume abundance ratio of the styrene monomer droplets included in the range of the average diameter ± 10% was 84.1%.

[Comparative Example] For comparison, the inside of the hydrophobic droplet production tank 12 and the polyvinyl alcohol aqueous solution, the styrene monomer simple substance, and the polyvinyl alcohol aqueous solution in the hydrophobic droplet production tank 12 were all heated to 25 ° C. An oil-in-water dispersion liquid in which droplets of styrene monomer are dispersed by being jetted at a flow rate of 1.2 to 1.4 cc / min / hole from the ejection hole 16 of the member 17 is obtained. It was recovered from the oil-in-water dispersion outlet 27. The average diameter of the styrene monomer droplets obtained at this time was 0.440 mm,
The volume abundance ratio of the styrene monomer droplets contained in the range of the average diameter ± 10% was 79.2%. For this reason, there was no flow range of styrene monomer in which 80% or more by volume of styrene monomer droplets contained in the range of average diameter ± 10% existed. Therefore, the temperature of the polyvinyl alcohol aqueous solution is 30 ° C and the temperature of the styrene monomer alone is 25
The flow rate is 1.28 to 1.31 cc /
The volume abundance of styrene monomer droplets contained in the range of average diameter ± 10% can be set to 80% or more over the range of min / pore, and the maximum volume abundance can be improved by 4.9%. Became.

[Embodiment 2] The hydrophobic liquid droplet production tank 12 is set to 25.
Keep the temperature at ℃
C., the temperature of the styrene monomer was set to 25.degree. C., and styrene monomer droplets were formed to investigate the particle size distribution. The average diameter of the styrene monomer droplets obtained at this time was 0.4.
The flow rate range of the styrene monomer is 21 mm and the styrene monomer droplets contained in the range of the average diameter ± 10% are 80% or more on the volume basis.
in / hole. The width of the flow rate range in which the styrene monomer droplets contained in the range of the average diameter ± 10% are 80% or more on the volume basis is 0.06 cc / min / hole, which is equal to the width obtained in the case of Example 1. It was doubled in comparison. In addition, the maximum value of the volume abundance ratio of the styrene monomer droplets included in the range of the average diameter ± 10% was 88.4%, which was 4.3% as compared with Example 1 and 9.2% as compared with Comparative Example. Was improved.

[Embodiment 3] The hydrophobic liquid droplet production tank 12 is set to 25.
With the temperature of the polyvinyl alcohol aqueous solution kept at 40 ° C., heated by the heater 24 and supplied, and the temperature of the styrene monomer at 40 ° C. and 25 ° C., styrene monomer droplets were formed and the particle size distribution thereof was investigated. The average diameter of the styrene monomer droplets obtained at this time was 0.416 mm, and the flow rate range of the styrene monomer in which the styrene monomer droplets included in the range of the average diameter ± 10% were 80% or more by volume was 1 It was 0.22 to 1.31 cc / min / hole. The width of the flow rate range in which the styrene monomer droplets contained in the range of the average diameter ± 10% are 80% or more on the volume basis is 0.
The width is 08 cc / min / hole, which is expanded by 0.02 cc / min / hole from the width obtained in the second embodiment. Further, the maximum value of the volume abundance ratio of the styrene monomer droplets included in the range of the average diameter ± 10% is 90.6%,
Compared with Example 1, 6.5%, compared with Example 2, 2.
The improvement was 2%, or 11.4% over the comparative example.

The embodiment of the present invention has been described above.
The present invention is not limited to this embodiment,
For example, while the temperature inside the hydrophobic droplet manufacturing tank is controlled to the same temperature as the hydrophobic liquid, the temperature can be controlled to the same temperature as the aqueous medium by making the hydrophobic liquid jet storage tank have a heat insulating structure. Although the present embodiment has been described by taking as an example the production method in the case of producing a powdery resin used for, for example, an ion exchange resin matrix by suspension polymerization, the production method of the hydrophobic droplets of the present invention is The present invention is not limited to the production of resinous resin, but can be widely applied to the production of uniform droplets.

[0028]

In the method for producing an oil-in-water dispersion according to claims 1 to 5, since the temperature of the aqueous medium is controlled within the range of 30 to 90 ° C, the temperature of the aqueous medium has a uniform particle size. The optimum temperature for forming hydrophobic droplets can be achieved, and there is little effect from changes in the flow rate and physical properties of the hydrophobic liquid and changes in the physical properties of the aqueous medium, and a stable and uniform particle size can be achieved over a wide flow rate range. It is possible to manufacture an oil-in-water type dispersion liquid in which the hydrophobic droplets are dispersed.

In particular, in the method for producing an oil-in-water dispersion according to claim 2, since the hydrophobic liquid is a polymerizable monomer, the obtained hydrophobic droplets can be easily polymerized, It is possible to maintain the shape of the hydrophobic droplet having the uniform particle size.

In the method for producing an oil-in-water dispersion according to claim 3, the temperature of the hydrophobic liquid is set to be 1 temperature higher than the polymerization initiation temperature.
Since the temperature is controlled to be 5 ° C. or lower, it is possible to prevent the polymerization of the hydrophobic liquid before producing the oil-in-water dispersion. As a result, it is possible to stably obtain hydrophobic droplets having high uniformity in particle size.

In the method for producing an oil-in-water dispersion according to claim 4, the difference between the temperature of the aqueous medium and the polymerization initiation temperature is 1
Since the temperature is controlled within 5 ° C., the difference between the temperature of the hydrophobic liquid and the temperature of the aqueous medium becomes small, and the uniformity of the particle size of the resulting hydrophobic droplets can be increased.

In the method for producing an oil-in-water dispersion according to claim 5, since the temperature of the hydrophobic liquid is controlled to 30 ° C or lower, the hydrophobic liquid is stored at a temperature lower than the polymerization initiation temperature. It is possible to prevent the polymerization of the ionic liquid. As a result, it is possible to stably obtain hydrophobic droplets having high uniformity in particle size.

[Brief description of drawings]

FIG. 1 is a side sectional view schematically showing an apparatus for producing an oil-in-water dispersion liquid to which a method for producing an oil-in-water dispersion liquid according to an embodiment of the present invention is applied.

FIG. 2 is a plan view of a nozzle member provided in the same apparatus for producing an oil-in-water dispersion liquid.

FIG. 3 is a side sectional view showing a modified example of the apparatus for producing the oil-in-water dispersion liquid.

[Explanation of symbols]

10: Device for producing oil-in-water dispersion, 11: Aqueous medium, 1
2: Hydrophobic droplet manufacturing tank, 13: Hydrophobic liquid, 14: Hydrophobic liquid storage tank, 15: Hydrophobic liquid supply pipe, 16: Jet hole,
17: Nozzle member, 18: Aqueous medium storage tank, 19: Aqueous medium supply pipe, 20: Hydrophobic liquid ejection storage tank, 21, 22: Supply pump, 23, 24: Heater, 25: Aqueous medium ejection part, 26: Hydrophobic Liquid droplets, 27: Oil-in-water type dispersion liquid discharge port,
28: Oil-in-water type dispersion liquid production apparatus, 29: Hydrophobic droplet production tank, 30: Jet hole, 31: Blow-in portion, 32: Nozzle member

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Miki Hirota             1-1 Kurosaki Shiroishi, Hachiman Nishi Ward, Kitakyushu City, Fukuoka Prefecture               Within Mitsubishi Chemical Corporation (72) Inventor Ryuzo Semura             1-1 Kurosaki Shiroishi, Hachiman Nishi Ward, Kitakyushu City, Fukuoka Prefecture               Within Mitsubishi Chemical Corporation (72) Inventor Yoshio Yoneda             1-1 Kurosaki Shiroishi, Hachiman Nishi Ward, Kitakyushu City, Fukuoka Prefecture               Within Mitsubishi Chemical Corporation (72) Inventor Junya Watanabe             1-1 Kurosaki Shiroishi, Hachiman Nishi Ward, Kitakyushu City, Fukuoka Prefecture               Within Mitsubishi Chemical Corporation F-term (reference) 4J011 AA08 JB08 KB08

Claims (5)

[Claims] 1. A hydrophobic liquid immiscible with the aqueous medium is ejected into an aqueous medium forming a continuous phase through a nozzle member having ejection holes to form the hydrophobic liquid in the aqueous medium. In the method for producing an oil-in-water dispersion in which hydrophobic droplets are dispersed, the temperature of the aqueous medium is controlled in the range of 30 to 90 ° C., the method for producing an oil-in-water dispersion. 2. The method for producing an oil-in-water dispersion according to claim 1, wherein the hydrophobic liquid is a polymerizable monomer. 3. The method for producing an oil-in-water dispersion according to claim 2, wherein the temperature of the hydrophobic liquid is controlled to be 15 ° C. or more lower than the polymerization initiation temperature. Manufacturing method. 4. The method for producing an oil-in-water dispersion according to claim 2 or 3, wherein the difference between the temperature of the aqueous medium and the polymerization initiation temperature is controlled within 15 ° C. Liquid manufacturing method. 5. The method for producing an oil-in-water dispersion according to any one of claims 1 to 4, wherein the temperature of the hydrophobic liquid is controlled to 30 ° C. or lower. Liquid manufacturing method.