JP3635575B2 - Monodisperse resin particle production method and production apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for producing monodispersed resin particles having a uniform particle size used in the chemical, medical, electronic material fields and the like.
[0002]
[Prior art]
Conventionally known methods for producing resin particles include suspension polymerization, emulsion polymerization, soap-free polymerization, seed polymerization, and dispersion polymerization.
[0003]
In the suspension polymerization method described above, an aqueous medium in which a dispersion stabilizer is dissolved is generally charged into a reaction vessel equipped with a stirrer, and a polymerizable monomer in which a polymerization initiator is dissolved in advance is charged while stirring the mixture, and heated. This is a method for obtaining spherical resin particles. What was obtained by this method had the fault that a particle size distribution was wide.
[0004]
On the other hand, in applications such as column fillers, spacers, toners, foams, etc., it is necessary that the particle diameters are uniform. Conventionally, since only those having the required particle size are separated by an operation such as classification, the efficiency is very poor, and particles having an unnecessary particle size have to be discarded.
[0005]
The emulsion polymerization method, the soap-free polymerization method, and the seed polymerization method described above have good monodispersity in particle size, but the range of particle sizes usually obtained is up to about several μm, and particle sizes larger than that are obtained. It is difficult to obtain particles.
[0006]
As a prior art, a method of controlling the particle size of an emulsion or the like using a mixer, a homogenizer or the like is generally known. That is, it is a method for obtaining desired resin particles by polymerizing a monomer by controlling the particle diameter of the dispersed phase of an emulsion with these mixers using a polymerizable monomer as a dispersed phase.
[0007]
In this method, since the particle size distribution of the dispersed phase is wide, the particle size distribution of the resin particles corresponding thereto is also wide.
[0008]
On the other hand, a membrane emulsification method is known as a method for improving monodispersibility. This is a method for producing an emulsion by feeding a dispersed phase into a continuous phase through a film made of polycarbonate, polytetrafluoroethylene, porous glass or the like.
[0009]
However, this method is limited in particle size. Therefore, there is a technique in which a hole for extruding a dispersed phase is tried using a photolithography technique. JP-A-2000-84384, JP-A-2000-15070, and JP-A-2002-119841 disclose methods for producing emulsions and microspheres using microchannels.
[0010]
[Problems to be solved by the invention]
In the emulsion production method using the above microchannel, the problems in the membrane emulsification method have been overcome, but the particle diameter of the obtained emulsion or microsphere is governed by the channel diameter. When manufacturing, a device with a different channel diameter for each particle size must be prepared, and it takes time to manufacture a complicated device. Furthermore, the thing of the particle size smaller than a channel diameter was not able to be produced. In addition, the production speed is slow and the productivity is poor.
[0011]
In view of the above situation, an object of the present invention is to provide a method and an apparatus for producing monodispersed resin particles having a high monodispersibility and a high production rate and easy particle size control.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides
[1] microswitch ejecting a dispersion phase comprising a polymerizable monomer through an opening which is connected to the micro-channel for a continuous phase flowing in the channel, making the droplets dispersed in the continuous phase comprising the dispersed phase A method of producing monodispersed resin particles for producing resin particles by polymerizing the polymerizable monomer, the droplet diameter of the generated dispersed phase is measured, and based on the result, the flow rate of the continuous phase and The droplet diameter is adjusted by adjusting at least one of the flow rates of the dispersed phase .
[0013]
[2] microswitch ejecting a dispersion phase comprising a polymerizable monomer from the microchannel intersecting its microchannel the continuous phase flowing in the channel, to produce droplets dispersed from the dispersion phase in the continuous phase, A method for producing monodispersed resin particles for producing resin particles by polymerizing the polymerizable monomer , wherein the droplet diameter of the generated dispersed phase is measured, and based on the result, the flow rate of the continuous phase and the dispersed phase are measured. The diameter of the liquid droplet is adjusted by adjusting at least one of the flow rates .
[0014]
[3] [1] above or the method of manufacturing monodisperse resin particles [2], wherein, interfacial contact angle of the dispersed phase of droplets consisting of polymerizable monomer in contact with the soaked flow path surface to the continuous phase Is 90 ° or more.
[0015]
[ 4 ] A dispersed phase composed of a polymerizable monomer is discharged from an opening connected to the microchannel to a continuous phase flowing through the microchannel, and droplets dispersed in the continuous phase composed of this dispersed phase are prepared. A method for producing monodisperse resin particles for producing resin particles by polymerizing the polymerizable monomer , wherein the droplet diameter of the generated dispersed phase is measured, and the target droplet diameter is determined based on the result. It is characterized by fractionating the dispersion liquid.
[0016]
[ 5 ] A dispersed phase composed of a polymerizable monomer is discharged from a microchannel intersecting the microchannel to a continuous phase flowing through the microchannel, and droplets dispersed in the continuous phase are produced from the dispersed phase, A method for producing monodisperse resin particles in which resin particles are produced by polymerizing a polymerizable monomer, the droplet diameter of the generated dispersed phase being measured, and a dispersion having a target droplet diameter based on the result The liquid is dispensed.
[0017]
[6] above [4] or in the method of manufacturing monodisperse resin particles according [5], interfacial contact angle of the dispersed phase of droplets consisting of polymerizable monomer in contact with the soaked flow path surface to the continuous phase Is 90 ° or more.
[0018]
[7] In the method for producing monodispersed resin particles according to [1], [2], [3], [4], [5] or [6], the diameter range of the resin particles obtained is mechanical. Without passing through the separation step, it is 1 μm or more and less than 1000 μm, and the coefficient of variation is 5% or less.
[0019]
[ 8 ] A microchannel for flowing a continuous phase, a microchannel for flowing a dispersed phase provided so as to cross the microchannel, a liquid feeding mechanism for flowing the continuous phase to the microchannel, and the dispersed phase A device for producing monodispersed resin particles, which is provided with a mechanism for feeding a liquid made of a polymerizable monomer to a microchannel and a mechanism for polymerizing the polymerizable monomer droplets, and the generated polymerizable monomer liquid It has a mechanism for adjusting at least one of the flow rate of the continuous phase and the flow rate of the dispersed phase according to the result measured by the mechanism for measuring the droplet diameter.
[0020]
[9] In the apparatus for producing monodisperse resin particles according to [8] above, part or all of the material of the member constituting the flow path is transparent, and the mechanism for enlarging the image of the droplet and the droplet And a mechanism for making the generation state observable.
[0021]
[ 10 ] A microchannel for flowing a continuous phase, a microchannel for flowing a dispersed phase provided so as to cross the microchannel, a liquid feeding mechanism for flowing the continuous phase to the microchannel, and the dispersed phase A device for producing monodispersed resin particles, which is provided with a mechanism for feeding a liquid made of a polymerizable monomer to a microchannel and a mechanism for polymerizing the polymerizable monomer droplets, and the generated polymerizable monomer liquid It has a mechanism for separating a continuous phase in which only a dispersed phase having a predetermined polymerizable monomer droplet diameter is dispersed based on a result of measurement by a mechanism for measuring a droplet diameter.
[0022]
[ 11 ] In the monodisperse resin particle production apparatus according to [ 10 ] above, a part or all of the material of the members constituting the flow path is transparent, and the mechanism for enlarging the image of the droplet and the droplet And a mechanism for making the generation state observable.
[0023]
Regarding the above [ 1] or [2 ], methods such as JP-A-2000-84384 cannot control the particle size of the emulsion obtained even if the flow rate of the continuous phase is changed. It is that the dispersed phase passes through the microchannel, but the continuous phase does not pass through the microchannel. In the present invention, the continuous phase is caused to flow through the microchannel, and the dispersed phase is formed into uniform droplets by the shearing force of the continuous phase.
[0024]
Regarding the above [ 3] or [6 ], when the interface contact angle of the droplets of the dispersed phase made of a polymerizable monomer in contact with the surface of the flow channel immersed in the continuous phase is less than 90 °, the dispersion due to the shear force of the continuous phase Phase splitting is unlikely to occur and uniform droplets are not generated.
[0025]
As a means for setting the interface contact angle to 90 ° or more, there is a means for selecting the material of the material for forming the flow path according to the material of the continuous phase or the dispersed phase, or for the surface treatment of the flow path surface. . As another means, there is a means by adding an additive capable of changing the surface tension such as a surfactant to the continuous phase or the dispersed phase. As the surface treatment means, a known method may be adopted. For example, a method of obtaining a film by applying a solution to a component that forms the film, vapor deposition, sputtering, CVD, and the like can be raised. As the surfactant, a known surfactant that is compatible with the continuous phase and the dispersed phase may be used.
[0026]
With respect to the above [ 1] or [2 ], this is a manufacturing method for more precise control over disturbance factors such as temperature change and mechanical vibration in order to obtain more uniform droplets. The droplet diameter of the generated dispersed phase is measured, and the droplet diameter is adjusted by adjusting at least one of the flow rate of the continuous phase and the flow rate of the dispersed phase based on the result. This corrects the flow disturbed by the disturbance factor.
[0027]
For the above [ 4] or [5 ], in order to obtain a more uniform particle size, only desired ones are collected and those having different diameters are excluded.
[0028]
Regarding the above [7], the diameter range of the resin particles is 1 μm or more and less than 1000 μm, and the coefficient of variation is 5% or less. As described above, in the prior art , those having a size of 1 μm or less can be produced by a method utilizing chemical equilibrium such as emulsion polymerization. Those having a thickness of 1000 μm or more can be produced by a laminar dropping method or the like. Conventionally, there has been no production method that can obtain resin particles having a coefficient of variation of 5% or less without a physical separation method such as classification.
[0029]
As the polymerizable monomer used in the present invention, known monomers may be used. For example, those conventionally polymerized by suspension polymerization may be used. For example, monovinyl aromatic compounds such as styrene, vinyl naphthalene and alkyl-substituted styrene, halo-substituted styrene such as bromo- or chloro-styrene, divinylbenzene, divinyltoluene, divinylxylene, divinylnaphthalene, trivinylbenzene, divinyldiphenyl ether and divinyldiphenyl Polyvinyl aromatic compounds such as sulfones, haloolefins such as vinyl chloride, vinyl halides, esters of α-β-ethylenically unsaturated carboxylic acids such as esters of acrylic acid or methacrylic acid, methyl methacrylate, ethyl acrylate, oxidation Vinyl is mentioned. Two or more of these may be mixed.
[0030]
In the case of a water-in-oil system, ethylenically unsaturated carboxylic acid amides such as acrylamide, methacrylamide, fumaramide, ethacrylamide, aminoalkyl esters and acid anhydrides of unsaturated carboxylic acids, acrylic acid, methacrylic acid, etc. A water-soluble polymerizable monomer such as an ethylenically unsaturated carboxylic acid may be used.
[0031]
Further, a polymerization initiator may be added to the dispersed phase used in the present invention. Examples of the polymerization initiator include known ones. For example, benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, potassium persulfate, avizosisobutyronitrile, azobispereronitrile, and the like can be used.
[0032]
In the case of a water-in-oil system, a water-soluble polymerization initiator such as persulfate, hydrogen persulfide, or hydroperoxide can be used.
[0033]
Moreover, when making it superpose | polymerize by light, a photoinitiator is used and polymerization adjuvants, such as another chain transfer agent, may be used.
[0034]
Further, other sensitizers, viscosity modifiers, solvents, surfactants and the like may be used for adjusting the surface tension as long as they do not affect the polymerization.
[0035]
It is preferable to add a dispersion stabilizer to the continuous phase so as not to break up and coalesce the formed droplets. Examples of the dispersion stabilizer include cellulose such as polyvinyl alcohol, polyvinyl pyrrolidone, carboxymethyl cellulose, and hydroxymethyl cellulose, starch. And water-soluble polymers such as gelatin, and poorly water-soluble inorganic salts such as tricalcium phosphate. In addition, a surfactant, a specific gravity adjuster and the like are included for adjusting the surface tension.
[0036]
The above is an example of an oil-in-water system, but in the case of a water-in-oil system, a continuous phase is an aliphatic hydrocarbon system such as n-hexane or n-octane, or a halogenated carbonization such as carbon tetrachloride. Aromatic hydrocarbon solvents such as hydrogen, toluene and xylene are used. Examples of the surfactant include sodium alkylbenzene sulfonate.
[0037]
The monomer droplets are solidified by polymerizing the monomer to obtain a dispersion of resin particles. The polymerization method is not particularly limited, for example, a method of increasing the temperature after adding a polymerization initiator to the emulsion, a method of increasing the temperature after dissolving the polymerization initiator in the dispersion phase composition in advance. And a method of irradiating light of a specific wavelength using a photopolymerization initiator, and the like, and may be appropriately selected depending on the type, reactivity, use, etc. of the reactive monomer.
[0038]
Resin particles are obtained by removing the continuous phase from the dispersion. The method for removing the continuous phase and collecting the resin particles is not particularly limited, and for example, a drying method such as a vacuum drying method or a spray drying method can be used. If there is a problem that unreacted monomer, surfactant, dispersant, etc. remain depending on the use of the solid fine particles, it is preferable to wash the resin particles by an extraction operation or the like before removing the continuous phase.
[0039]
Any known method may be used as the measurement method described in [ 1] or [2 ]. The above [ 8] or [10 ] is a device for that purpose. As a method, for example, a method based on image analysis is given. The image of the droplet is photographed with a camera equipped with a lens for optically enlarging, captured in a computer, and measured on the computer. The result is fed back to control the flow rate of at least one of the continuous phase and the dispersed phase. Any known method may be used as the means for controlling the flow rate. For example, a method of providing a flow rate adjustment valve is raised.
[0040]
Any known method may be used as the sorting method described in [ 4] or [5 ] above. For example, a method by switching a valve or switching a container can be mentioned.
[0041]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0042]
First, a first embodiment of the present invention will be described.
[0043]
FIG. 1 is a schematic view of a microchannel plate showing a first embodiment of the present invention, and FIG. 2 is a schematic view of an apparatus for producing monodisperse resin particles showing a first embodiment of the present invention.
[0044]
In FIG. 1, 101 is a microchannel plate, 102 is a continuous phase path, 103 is a continuous phase supply port, 104 is a dispersed phase path, 105 is a dispersed phase supply port, 106 is a discharge path, 107 is a discharge port, and 108 is a microchannel. It is.
[0045]
In FIG. 2, 111 is a continuous phase syringe pump, 112 is a dispersed phase syringe pump, and 113 is a container (flask) for receiving the solution.
[0046]
As shown in FIG. 1, a microchannel plate 101 provided with glass microchannels 108 was produced. This was arranged between syringe pumps 111 and 112 and flask 113 as shown in FIG. As the polymerization initiator added to the dispersed phase, divinylbenzene added with benzoyl peroxide was used, and as a continuous phase, a 3% solution of polyvinyl alcohol (GL-03 manufactured by Nippon Gosei Kagaku) was used. Then, the continuous phase was pumped to the microchannel 108 using the continuous phase syringe pump 111 at a continuous phase of 20 ml / hr and the dispersed phase syringe pump 112 at a flow rate of the dispersed phase of 0.1 ml / hr. The obtained dispersion was heated to 80 ° C. and stirred to polymerize the monomer droplets to obtain resin particles. The resin particles thus obtained had an average particle size of 68 μm and a coefficient of variation of 3.6%.
[0047]
Next, a second embodiment of the present invention will be described.
[0048]
The same procedure as in Example 1 was performed except that the flow rate of the continuous phase was 40 ml / hr. The obtained resin particles had an average particle size of 41 μm and a coefficient of variation of 4.4%.
[0049]
Next, a third embodiment of the present invention will be described.
[0050]
The interface contact angle in the first example was measured and found to be 122 °.
[0051]
Next, a fourth embodiment of the present invention will be described.
[0052]
FIG. 3 is a schematic view of an apparatus for producing monodisperse resin particles showing a fourth embodiment of the present invention.
[0053]
In this figure, 201 is a CCD camera, 202 is a lens of the CCD camera 201, and 203 is a computer that processes image data from the CCD camera 201. Since other parts are the same as those of the first embodiment, description thereof is omitted.
[0054]
As shown in FIG. 3, the CCD camera 201 was equipped with a lens 202 and the microchannel plate 101 used in the first example was observed. The droplet was photographed with the CCD camera 201, the image data was taken into the computer 203, and the flow rate was finely adjusted while measuring the droplet diameter with the image analysis software. At this time, the flow rate was 20 ml / hr for the continuous phase and 0.1 ml / hr for the dispersed phase. Resin particles were obtained by polymerization in the same manner as in the first example. The obtained resin particles had an average particle size of 67 μm and a coefficient of variation of 2.4%.
[0055]
Next, a fifth embodiment of the present invention will be described.
[0056]
Measurement was performed using the same measurement apparatus as in the fourth example, and when the result did not fall within the predetermined droplet diameter range, the container 113 that received the solution was removed, and only those within the predetermined range were collected. Resin particles were obtained by polymerization in the same manner as in the first example. The obtained resin particles had an average particle size of 67 μm and a coefficient of variation of 2.1%.
[0057]
In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.
[0058]
【The invention's effect】
As described above in detail, according to the present invention, since the dispersed phase is formed into droplets by the uniform shear force of the continuous phase flowing through the microchannel, uniform monomer droplets can be efficiently generated at a high speed. Can do. The particle size can be controlled by the flow rate of the continuous phase. Furthermore, various particle sizes can be produced with a single manufacturing apparatus.
[Brief description of the drawings]
FIG. 1 is a schematic view of a microchannel plate showing a first embodiment of the present invention.
FIG. 2 is a schematic view of a monodisperse resin particle production apparatus showing a first embodiment of the present invention.
FIG. 3 is a schematic view of a monodisperse resin particle production apparatus showing a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 101 Microchannel plate 102 Continuous phase path 103 Continuous phase supply port 104 Dispersed phase path 105 Dispersed phase supply port 106 Discharge path 107 Discharge port 108 Microchannel 111 Continuous phase syringe pump 112 Dispersed phase syringe pump 113 Container (flask) which receives a solution
DESCRIPTION OF SYMBOLS 201 CCD camera 202 CCD camera lens 203 Computer which processes image data of CCD camera

Claims (11)

A dispersed phase composed of a polymerizable monomer is discharged from an opening connected to the microchannel to a continuous phase flowing through the microchannel, and droplets dispersed in the continuous phase composed of the dispersed phase are prepared, and the polymerization is performed. A monodisperse resin particle production method for producing resin particles by polymerizing a polymerizable monomer, which measures the droplet diameter of the generated dispersed phase, and based on the result, the flow rate of the continuous phase and the flow rate of the dispersed phase A method for producing monodisperse resin particles, wherein the diameter of the droplets is adjusted by adjusting at least one of the above . Dispersing a dispersed phase composed of a polymerizable monomer from a microchannel intersecting the microchannel with respect to a continuous phase flowing through the microchannel, producing droplets dispersed from the dispersed phase into the continuous phase, and the polymerizable monomer A method for producing monodispersed resin particles by polymerizing a resin particle , wherein the droplet diameter of the generated dispersed phase is measured, and based on the result, at least the flow rate of the continuous phase and the flow rate of the dispersed phase are measured. A method for producing monodisperse resin particles, wherein the diameter of the droplets is adjusted by adjusting one of them . Interfacial contact angle of the dispersed phase of droplets consisting of polymerizable monomer in contact with the soaked flow path surface to the continuous phase is, monodisperse resins of claim 1 or 2, wherein the at least 90 ° Particle manufacturing method. A dispersed phase composed of a polymerizable monomer is discharged from an opening connected to the microchannel to a continuous phase flowing through the microchannel, and droplets dispersed in the continuous phase composed of the dispersed phase are prepared, and the polymerization is performed. A method for producing monodispersed resin particles, wherein resin particles are produced by polymerizing a polymerizable monomer, the droplet diameter of the generated dispersed phase being measured, and a dispersion having a target droplet diameter based on the result A method for producing monodisperse resin particles, wherein Dispersing a dispersed phase composed of a polymerizable monomer from a microchannel intersecting the microchannel with respect to a continuous phase flowing through the microchannel, producing droplets dispersed from the dispersed phase into the continuous phase, and the polymerizable monomer A method for producing monodisperse resin particles by producing a resin particle by polymerizing a dispersion, wherein the droplet diameter of the generated dispersed phase is measured, and based on the result, a dispersion having a target droplet diameter is separated. A method for producing monodisperse resin particles, comprising: The monodisperse resin particles according to claim 4 or 5 , wherein an interface contact angle of a droplet of a dispersed phase made of a polymerizable monomer in contact with a flow path surface immersed in the continuous phase is 90 ° or more. Manufacturing method.   The range of the diameter of the obtained resin particles is 1 μm or more and less than 1000 μm without passing through a mechanical separation step, and the coefficient of variation is 5% or less. A process for producing monodisperse resin particles according to 5 or 6. A microchannel for flowing a continuous phase, a microchannel for flowing a dispersed phase provided so as to intersect the microchannel, a liquid feeding mechanism for flowing the continuous phase to the microchannel, and a polymerizable monomer serving as the dispersed phase A monodisperse resin particle manufacturing apparatus provided with a mechanism for feeding a liquid comprising a microchannel and a mechanism for polymerizing the polymerizable monomer droplets. An apparatus for producing monodispersed resin particles, comprising a mechanism for adjusting at least one of a flow rate of a continuous phase and a flow rate of a dispersed phase based on a result of measurement by a measuring mechanism.   A part or all of the material of the member constituting the flow path is transparent, and has a mechanism for enlarging the image of the droplet and a mechanism for enabling observation of the generation state of the droplet. The manufacturing apparatus of the monodispersed resin particle of 8. A microchannel for flowing a continuous phase, a microchannel for flowing a dispersed phase provided so as to intersect the microchannel, a liquid feeding mechanism for flowing the continuous phase to the microchannel, and a polymerizable monomer serving as the dispersed phase A monodisperse resin particle manufacturing apparatus provided with a mechanism for feeding a liquid comprising a microchannel and a mechanism for polymerizing the polymerizable monomer droplets. An apparatus for producing monodispersed resin particles, comprising a mechanism for separating a continuous phase in which only a dispersed phase having a predetermined polymerizable monomer droplet diameter is dispersed based on a result measured by a measuring mechanism. A part or all of the material of the member constituting the flow path is transparent, and has a mechanism for enlarging the image of the droplet and a mechanism for observing the generation state of the droplet. The manufacturing apparatus of the monodispersed resin particle of 10 .

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