JP2006095481A - Apparatus and method for producing fine particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for producing a fine particle, wherein the fine particle can be produced by producing a minute liquid droplet by using a minute flow passage and hardening the minute liquid droplet just after produced without deforming the minute liquid droplet and which are adaptable to industrial mass production. <P>SOLUTION: The apparatus for producing the fine particle is composed of: a minute flow passage structure having a dispersed phase introducing port, a dispersed phase introducing flow passage, a continuous phase introducing port, a continuous phase introducing flow passage, a discharge flow passage from an intersecting part of the dispersed phase introducing flow passage with the continuous phase introducing flow passage to a discharge port and the discharge port for discharging the fine particle produced by merging a dispersed phase with a continuous phase in the discharge flow passage; and a microwave irradiation means for hardening the produced fine particle. This method for producing the fine particle comprises the steps of: introducing both of the dispersed phase and the continuous phase into the minute flow passage to merge with each other and produce the fine particle; and irradiating the produced fine particle with a microwave to harden the fine particle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fine particle production apparatus and a fine particle production method suitably used for producing fine gel particles used for sorting, separation column fillers and the like.

  In recent years, by using a microchannel structure having a microchannel having a length of about several centimeters on a glass substrate or a resin substrate of several centimeters square and having a width and a depth of sub μm to several hundred μm, Attention has been focused on research on chemical treatment such as chemical reaction and extraction, and generation of microdroplets and fine particles by liquid transfer. For example, Patent Document 1 and Non-Patent Document 1 describe examples in which chemical treatment is performed. Further, for example, Patent Document 2, Patent Document 3, and Non-Patent Document 2 describe examples of generating micro droplets.

  Regarding the technology for generating microdroplets in the microchannel, for example, in Non-Patent Document 2, as shown in FIG. 1 and FIGS. 2 and 3 showing cross sections AA ′ and BB ′ in FIG. 1 has a T-shaped micro-channel structure having a continuous phase inlet 2, a continuous phase inlet 3, a dispersed phase inlet 4, a dispersed phase inlet 5, a discharge channel 7 and a discharge port 8. The joining part 6 exists in the part where the introduced continuous phase and the dispersed phase join. The depth of each microchannel is 100 μm, the introduction channel width for introducing the dispersed phase is 100 μm, and the introduction channel width for introducing the continuous phase is 300 to 500 μm. When the liquid is fed while controlling the flow rate of the continuous phase, it is possible to generate extremely uniform micro droplets at the junction where the dispersed phase and the continuous phase merge through the flow path. It is also possible to control the particle size of the fine droplets generated by controlling the flow rates of the dispersed phase and the continuous phase.

  The microdroplets generated in this way have a relatively small variation in the particle size of the microdroplets and are cured by cross-linking polymerization of the compounds forming the microdroplets. Attempts have been made to use fine gel particles having a uniform particle size used for separation column fillers and the like. However, if the generated microdroplet is collected in a beaker or the like outside the microchannel and then cured by cross-linking polymerization or the like, the shape of the microdroplet is collected after the microdroplet is collected and cured. This causes a problem that the dispersion of the particle diameters of the hardened fine particles is increased because of the collapse of the liquid droplets or the coalescence of the fine droplets.

JP 2003-225900 A International Publication WO02 / 068104 Pamphlet Japanese Patent No. 3511238 H. Hisamoto et. al. (H. Hisamoto et al.) “Fast and high conversion phase-transfer synthesis exploitation the liquid-liquid interface formed in a microchannel chip”, Chem. Commun. , 2001, 2662-2663. Takashi Nishisako et al., “Liquid microdroplet generation in microchannels”, Proceedings of the 4th Chemistry and Microsystem Study Group, 59 pages, 2001

  As described above, at the stage where microdroplets are generated using the microparticle generation technology in the microchannel, the variation in the particle size of the microdroplets is relatively small and uniform. Collecting outside the road and curing the microdroplet by cross-linking polymerization etc., the shape of the microdroplet collapses or coalesces between the microdroplet from collecting the microdroplet to curing, The variation in the particle size of the cured fine particles becomes large. Therefore, further improvement has been demanded for use in fine gel particles having a uniform particle size used for sorting, separation column packing, and the like.

  The present invention has been made in view of the above-described problems, and generates microparticles by curing microdroplets immediately after generating microdroplets without destroying the shape of microdroplets generated using microchannels. An object of the present invention is to provide a fine particle production apparatus and a fine particle production method that can be applied to industrial mass production.

  The fine particle production apparatus of the present invention capable of solving the above problems includes a dispersed phase introduction port and a dispersed phase introduction channel for introducing a dispersed phase, a continuous phase introduction port and a continuous phase introduction channel for introducing a continuous phase, and the dispersion A discharge channel extending from an intersection where the phase introduction channel and the continuous phase introduction channel intersect to the discharge port, and a discharge port for discharging the fine particles generated by the combination of the dispersed phase and the continuous phase in the discharge channel. Is a fine particle manufacturing apparatus including a micro flow channel structure including the above and microwave irradiation means for curing the fine particles. In the method for producing fine particles of the present invention, a dispersed phase and a continuous phase are introduced into a minute flow path, and both are combined to produce fine particles, and then the produced fine particles are irradiated with microwaves and cured. Is the method.

  In the case of overheating with a conventional heater or the like, curing starts from the outside of the microdroplet and hardens toward the inside, so it takes time to cure and the curing rate differs between the outside and inside of the microdroplet, which is effective The internal composition of the fine particles was not uniform. However, as in the present invention, the entire structure of the microdroplet is obtained by using the microwave irradiation in the prescription in which the apparatus is provided with the microwave irradiation means and the generated fine particles are irradiated with the microwave. Are cured almost simultaneously, so that the microdroplets can be cured in a short time, and the outer and inner sides of the microdroplets are uniformly cured, and fine particles having a uniform internal composition can be generated.

  Note that the fine particles in the present invention include fine droplets and fine particles obtained by curing the fine droplets unless otherwise specified. In addition, the term “cured” refers to a mode in which the entire fine particles are cured, and curing to such an extent that the shape of the fine particles is not broken and the particles are not coalesced by curing only the surface of the fine particles (hereinafter referred to as “semi-cured” "). A micro droplet may be simply expressed as a droplet.

  Further, in the fine particle manufacturing apparatus of the present invention, the microwave irradiation means used irradiates the fine particles generated in the microchannel structure with microwaves, or the microparticles discharged from the discharge port of the microchannel structure are microscopic. It irradiates waves. That is, in the fine particle manufacturing apparatus according to the present invention, the micro droplet generated at the intersection of the dispersed phase introduction channel and the continuous phase introduction channel of the micro channel structure passes through the discharge channel and passes through the micro channel structure. Rather than being collected by an external beaker after exiting the body's discharge port and then cured by heating, light irradiation, microwave irradiation, etc., the micro liquid passing through the discharge channel in the micro channel structure An apparatus configuration that cures microparticles by irradiating the droplets with microwaves, or by irradiating the droplets with microwaves passing through a narrow tube such as a Teflon (registered trademark) tube from the outlet of the microchannel structure Become.

  By doing so, it becomes possible to produce fine particles by continuously curing the produced micro droplets while feeding them, and collecting the micro droplets generated in the discharge channel once outside. When the microdroplets are cured by cross-linking polymerization, etc., the shape of the microdroplets can be prevented from being deformed and the coalescence of the microdroplets can be suppressed, and deterioration of the dispersion degree of the cured fine particles can be suppressed. be able to.

  Here, the dispersion degree of the particle diameter of the fine particles (hereinafter referred to as “particle diameter dispersion degree”) is the average deviation of the particle diameter (hereinafter referred to as “average particle diameter”). It is defined as the divided value. Note that “dispersion degree of particle diameter” and “variation of particle diameter” described in this specification both mean “dispersion degree of particle diameter”.

  In the present invention, the shape of the flow path formed from the dispersed phase introduction flow path, the continuous phase introduction flow path, and the discharge flow path is preferably Y-shaped. The angle at which the continuous phase introduction flow path intersects can be arbitrarily controlled, and the particle diameter of the generated fine particles can be changed by changing the angle at which the dispersed phase introduction flow path and the continuous phase introduction flow path intersect. Can be controlled. Thus, by making the channel shape Y-shaped, and further controlling the angle of the Y-shape, the average particle size of the target fine particles can be controlled, and the degree of particle size dispersion can be made as small as possible. Fine particles can be produced according to the purpose.

  The microwave used in the present invention is classified into an electromagnetic wave having a slightly longer wavelength as compared with ultraviolet rays, visible light, and infrared rays, and usually has a wavelength of about 1 mm to 1 m. For this reason, the molecular dipole of the target molecule is rotated by irradiating the minute flow channel (fine particle before curing) obtained from the dispersed phase and the continuous phase with a microwave to the minute channel as in the present invention. It is presumed that thermal energy is generated (dielectric heating) by this, and the thermal energy causes, for example, a polymerization reaction to cure the microdroplets.

  In addition, heating by microwave irradiation is more direct than energy heating (heating the target molecule itself), and the target molecule is not limited as long as the target molecule is other than a conductor such as a metal. If it is dielectric materials, such as organic substance, it has the characteristic that it will not specifically limit, It is thought that it is effective in the microparticle manufacture of this invention.

  On the other hand, in the polymerization by heating with a heater, when the temperature rise by the heater generates a radical that initiates the polymerization of droplets, when one radical is generated, the polymerization starts in a chain like radical polymerization, for example. In other words, in the polymerization by the heater, the target substance is not particularly selected as long as it is polymerized, but heat is transferred from the medium that conducts heat, that is, the container to be heated, to the solvent and the molecule to be heated to give energy. Thermal efficiency is not efficient.

  In addition, since the wavelength such as ultraviolet rays is short, that is, high energy such as ultraviolet rays directly gives energy to the target molecule to generate radicals that start polymerization of the droplets, and the polymerization starts in a chain. Although energy efficiency is improved because energy is directly applied, the target substance is limited to a material (UV curable resin) that starts polymerization by absorbing ultraviolet energy.

  As described above, micro droplets by microwave irradiation have an excellent effect that the selection range of the material of the droplet material is widened and the thermal efficiency and the like in the processing can be improved.

  The microwave generation method in the microwave irradiating means used in the fine particle production apparatus of the present invention is mainly a combination of a klystron using an electron tube, a rotating electron driven by a static magnetic field, and an electromagnetic wave that rotates around a circle. Magnetotubes (also called magnetrons) that oscillate in the horn, impatt diodes (semiconductor oscillators) that use the avalanche phenomenon, Gunn diodes (semiconductor oscillators) that use the travel time of electrons and holes In the present invention, there is no particular limitation as long as the object can be achieved, but a magnetron type can be adopted from the viewpoint of procurement and cost of the apparatus.

  The microwave output used in the present invention is in the range of 50 to 1000 W, preferably in the range of 300 to 600 W. If it is less than 250 W, curing of the fine droplets due to the polymerization reaction may not proceed smoothly. On the other hand, if it exceeds 650 W, an excessive branch structure due to polymerization proceeds to a desired degree in the effected fine particles. This is because an unfavorable situation may occur such that a product having specifications cannot be obtained or coloring is caused.

  Further, the magnetron frequency of microwave irradiation can be 300 MHz to 300 GH, but it can be used in industrial, medical, chemical applications, etc. 433.92 ± 0.87 MHz, 2450 ± 50 MHz, 5800 ± 75 MHz, 24. 125 ± 0.125 GHz can be used, and 2450 ± 50 MHz and 5800 ± 75 MHz which can be generally used are preferable. Hereinafter, the present invention will be described in more detail with reference to the drawings.

  As shown in FIG. 4, the microwave irradiation 23 may be performed after the micro droplet comes out of the micro channel structure from the outlet 8 of the micro channel structure, or as shown in FIG. Immediately after the micro droplet is generated at the junction 6 (the portion where the dispersed phase introduction channel and the continuous phase introduction channel intersect) of the Y-shaped channel (the channel constituted by the introduction channel and the discharge channel). Alternatively, the microwave irradiation 23 may be performed to cure in the discharge channel provided in the microchannel structure. In the latter case, it is possible to reduce the coalescence and splitting of microdroplets further than in the former case, and it is possible to generate more uniform fine particles. However, when the microwave irradiation 23 is performed in the discharge channel provided in the channel structure as in the latter case, the microwave is irradiated on the dispersed phase 23 before the micro droplet is generated. As shown in FIG. 5, the portion of the flow channel before the micro droplet is generated and the portion of the flow channel that cures the micro droplet by the microwave irradiation 23 as shown in FIG. Therefore, it is necessary to install the microwave absorber 13 so that the microwave irradiation can be performed only at the necessary locations. Here, the material of the microwave absorber may be appropriately selected from known materials, for example, ferrite, soft magnetic metal powder, carbonyl iron-based magnetic powder mixed with a binder such as rubber or resin, polyester, etc. There are a copper-plated base formed on top and nickel-plated on top, and a silver-coated cloth.

  In the present invention, when micro droplets are cured by microwave irradiation, the entire micro droplets may be cured. However, the shape of the micro droplets may be destroyed by curing only the surface of the micro droplets. Alternatively, it may be semi-cured to such an extent that coalescence of the microdroplets does not occur. When semi-cured in this way, the semi-cured fine particles are collected with a beaker or the like, and are completely cured again by microwave irradiation, light irradiation, or heating, whereby fine particles having a uniform particle diameter can be obtained. In the case of such semi-curing, the time required for the micro droplets to pass through the microwave irradiation site can be further shortened.

  The dispersed phase used in the present invention is for the purpose of the present invention to efficiently generate fine particles, and in order to achieve this object, the flow path in the microchannel structure can be fed, and the microchannel structure The liquid is not particularly limited as long as it is a liquid substance containing a substance that generates micro droplets by the body and is cured by microwave irradiation. For example, a photopolymerizable or thermosetting monomer such as epoxy or acrylic, a monomer for polymerization such as styrene, a crosslinking agent such as divinylbenzene, or a raw material for gel production such as a polymerization initiator is dissolved in an appropriate solvent. Refers to the media. Moreover, it may be a slurry in which a solid phase is partially mixed in the dispersed phase. In addition, when the use of fine particles is used for a filler gel of a column for high performance liquid chromatography, the dispersed phase is preferably a medium containing a raw material for gel production.

  Similar to the dispersed phase, the continuous phase used in the present invention is capable of feeding a channel in the microchannel structure, and is used to generate microdroplets from the dispersed phase by the microchannel structure. The component is not particularly limited as long as it can form liquid droplets and can form fine droplets. Further, it may be a slurry in which a solid substance is partially mixed in the continuous phase. Further, when the fine particle is used for a packing gel of a column for high performance liquid chromatography, the continuous phase is a medium containing a dispersing agent for gel production, for example, dispersion for gel production of polyvinyl alcohol. A medium in which the agent is dissolved in a suitable solvent is preferable.

  In addition, the dispersed phase and the continuous phase need to be substantially incompatible with each other or have no compatibility in order to generate microdroplets. For example, when an aqueous phase is used as the dispersed phase, the continuous phase It is preferable to use an organic phase such as butyl acetate that does not substantially dissolve in water. Moreover, the reverse is true when an aqueous phase is used as the continuous phase.

  Since a gel can be produced according to the present invention, a gel having a uniform particle size useful for separation and purification of substances can be obtained by using such a dispersed phase and continuous phase. Furthermore, fine particles having a uniform particle diameter can be produced by using the fine particle production apparatus of the present invention described above.

  In the method for producing fine particles of the present invention, as shown in FIG. 6, the microchannels 10 provided in the microchannel structure 15 are Y-shaped microchannels, and three are arranged in a Y-shape. One of the microchannels is a dispersed phase introduction channel 5 for introducing a dispersed phase, and one of the remaining two microchannels is a continuous phase introduction channel 3 for introducing a continuous phase. This is a method for producing fine particles, which is a discharge flow channel 7 in which a dispersed phase and a continuous phase are merged at a merging portion 6 of a micro flow channel to generate fine particles, and the remaining one micro flow channel discharges the generated fine particles. This is a fine particle manufacturing method in which the particle diameter of the generated fine particles is controlled by changing the angle 9 at which the introduction flow path for introducing the phase and the introduction flow path for introducing the continuous phase intersect at the junction 6. By curing such fine particles, whose particle size is controlled using such Y-shaped microchannels, by microwave irradiation, the particle size dispersion degree of the fine particles can be further improved. Using this Y-shaped microchannel, the particle size of the generated fine particles is controlled by changing the angle at which the introduction channel for introducing the dispersed phase and the introduction channel for introducing the continuous phase intersect. This method is easier to control and suitable for industrial mass production than the conventional method of controlling the particle diameter of the fine particles by changing the introduction speed of the dispersed phase and the continuous phase in the production of fine droplets or fine particles. In particular, if the introduction speed of the dispersed phase and the introduction speed of the continuous phase are substantially the same, a single introduction device such as a micropump is used for both the dispersed phase feeding and the continuous phase feeding. It is excellent in terms of cost, such as being sufficient. Note that the introduction rate here is substantially the same means a variation range of the introduction rate such that the dispersion degree of the particle size of the generated fine particles is generated with a variation of less than 8%.

  Hereinafter, the fine channel structure constituting the fine particle production apparatus of the present invention will be described in more detail.

  As shown in FIG. 7, the dispersed phase inlet 4 for introducing the dispersed phase of the microchannel structure 15 constituting the fine particle manufacturing apparatus of the present invention means an opening for introducing the dispersed phase. The introduction port may be provided with a fillet joint 19 that is an appropriate connection portion to provide a mechanism for continuously introducing the dispersed phase. Similarly, the continuous phase introduction port 2 for introducing the continuous phase of the microchannel structure constituting the fine particle production apparatus of the present invention means an opening for introducing the continuous phase, and further to this introduction port. It is good also as a mechanism which provides the fillet joint 19 which is a suitable connection part, and introduces a continuous phase continuously.

  The introduction flow path for introducing the dispersed phase communicates with the introduction port, and the dispersed phase is introduced and fed along the introduction flow path. The shape of the introduction channel affects the control of the shape and particle size of the fine droplets or fine particles, but the width should be several hundreds μm or less, and it should be Y-shaped including the discharge channel. . Similarly, the introduction flow path for introducing the continuous phase is also in communication with the introduction port, and the continuous phase is introduced and fed along this introduction flow path. The shape of the introduction channel has an effect on controlling the shape and particle size of the fine droplets or fine particles, but the width should be several hundreds μm or less, and it should be Y-shaped including the discharge channel. .

  The discharge channel communicates with the above two introduction channels and the discharge port, and after the dispersed phase and the continuous phase merge, the liquid is fed along the discharge channel and discharged from the discharge port. The shape of the discharge channel is not particularly limited, but the width may be several hundreds μm or less, and it may be Y-shaped including the introduction channel. The discharge port 8 means an opening for discharging the generated fine droplets or fine particles obtained by curing the droplets by microwave irradiation, and further, a fillet joint 19 which is an appropriate connection portion to the discharge port. It is good also as a mechanism which discharges | emits continuously the phase containing the microparticles | fine-particles which were provided with, or the microparticles | fine-particles which hardened the microdroplets by microwave irradiation. Note that these channels are sometimes referred to as minute channels in this specification.

  Furthermore, in the microchannel structure of the present invention, as shown in FIG. 6, the introduction channel for introducing the dispersed phase and the introduction channel for introducing the continuous phase intersect at an arbitrary angle 9; It is preferable that these two introduction flow paths are connected to the discharge flow path at an arbitrary angle. By setting the angle at which the two introduction flow paths intersect to be an arbitrary angle, it is possible to control the micro droplets generated at the merging portion to a desired particle size, that is, the particle size is controlled. By curing the formed fine droplets by microwave irradiation, the particle size dispersion degree of the fine particles can be further improved. The setting of the crossing angle may be appropriately determined according to the target particle size of the fine droplets.

  Further, as an aspect of the shape of the discharge flow path 7 in the vicinity of the junction 6 of the micro flow path shown in FIG. 10, as shown in FIG. 11, discharge from the intersection 6 where the dispersed phase and the continuous phase intersect to the discharge port It is preferable that the width of the discharge flow path is narrow at a part of the flow path 7. In addition to the mode shown in FIG. 11, the flow path constituting wall along the dispersed phase flow path is formed in a convex shape so as to partially narrow the discharge flow path 7 at the junction 6 as shown in FIGS. Alternatively, both of these modes can increase the liquid feeding flow velocity and enable uniform droplet generation at the junction 6.

  Furthermore, it is preferable that the portion where the width of the discharge channel is narrow is at or near the intersection in the discharge channel, and in particular, the portion where the width of the discharge channel is narrow is the intersection of the discharge channel. It is preferable to be on the introduction flow path side of the dispersed phase of the part.

  The microchannel structure of the present invention has the structure and performance described above. As shown in FIG. 6, the dispersed phase introduction port 4 and the dispersed phase introduction channel 5 for introducing the dispersed phase, Continuous phase introduction port 2 and continuous phase introduction flow path 3 for introducing a continuous phase, merge section 6 where two introduction flow paths intersect, discharge flow path 7 for discharging liquid containing microdroplets or fine particles, and discharge The micro-channel structure 15 having the outlet 8 has a micro-channel substrate 13 in which the micro-channel is formed on at least one surface and a predetermined micro-channel so as to cover the surface on which the micro-channel is formed. The cover body 14 in which at least three small holes for communicating the microchannel and the microchannel structure outside may be laminated and integrated at the position. As a result, the fluid can be introduced from the outside of the microchannel structure into the microchannel and discharged again to the outside of the microchannel structure. It is possible to pass through the minute flow path. In this case, the fluid can be fed by mechanical means such as a micropump.

  The material of the micro-channel substrate and the cover body on which the micro-channel is formed can be formed by processing the micro-channel when the microwave irradiation is performed in the discharge channel provided outside the micro-channel structure. However, it is desirable to have excellent chemical resistance and appropriate rigidity. For example, glass, quartz, ceramic, silicon, or metal or resin may be used. However, the discharge channel is preferably made of a material that allows microwaves to pass, such as glass such as quartz glass and Pyrex (registered trademark) glass, and resin such as polypropylene. On the other hand, when microwave irradiation is performed in the microchannel or discharge channel provided in the microchannel structure, the microchannel can be formed and processed with excellent chemical resistance and moderate rigidity. And a material through which microwaves can pass, that is, glass such as quartz glass and Pyrex (registered trademark) glass, resin such as polypropylene, and the like are preferable.

  The size and shape of the microchannel substrate and the cover body are not particularly limited, but the thickness is preferably about several mm or less. The small holes arranged in the cover body communicate with the microchannel and the outside of the microchannel structure, and when used as a fluid inlet or outlet, the diameter is preferably, for example, several mm or less. The small holes in the cover body can be processed chemically, mechanically, or by various means such as laser irradiation or ion etching.

  In the microchannel structure of the present invention, the microchannel substrate on which the microchannels are formed and the cover body are laminated by means such as heat treatment bonding or adhesion using an adhesive such as a photo-curing resin or a thermosetting resin. Can be integrated. One microchannel may be formed on the microchannel substrate, or a plurality of microchannels may be formed and integrated. A plurality of microchannel substrates having microchannels may be stacked.

  The fine particle production apparatus of the present invention includes a dispersed phase introduction port and a dispersed phase introduction channel for introducing a dispersed phase, a continuous phase introduction port and a continuous phase introduction channel for introducing a continuous phase, the dispersed phase introduction channel, and the A micro flow path comprising a discharge flow path from an intersection where the continuous phase introduction flow path intersects to a discharge opening, and a discharge opening for discharging fine particles generated by the combination of the dispersed phase and the continuous phase in the micro flow path. It is a fine particle manufacturing apparatus including a structure and microwave irradiation means for curing the fine particles.

  In this way, the dispersed phase and the continuous phase are merged at the merging portion of the micro flow path to form the dispersed phase into micro droplets with a very uniform particle size, and then the generated micro droplets are irradiated with microwaves. With continuous sequential curing, microdroplets can be cured or semi-cured in a short time, and fine particles with a very uniform internal structure of the cured particles can be efficiently generated. .

  In addition, the method for producing fine particles of the present invention is a method for producing fine particles in which a dispersed phase and a continuous phase are introduced into a microchannel, and both are combined to produce fine particles, and then the produced fine particles are irradiated with microwaves to be cured. Is the method.

  In this way, it is possible to produce fine particles by continuously curing the produced micro droplets while feeding them, and collect the micro droplets generated in the micro flow channel once outside. When the microdroplets are cured by cross-linking polymerization, etc., the shape of the microdroplets can be prevented from being deformed and the coalescence of the microdroplets can be suppressed, and deterioration of the dispersion degree of the cured fine particles can be suppressed. be able to.

  In the fine particle production apparatus of the present invention, the shape of the flow path formed from the dispersed phase introduction flow path, the continuous phase introduction flow path, and the discharge flow path is Y-shaped, and the dispersed phase introduction in the micro flow path structure is performed. The angle at which the flow path and the continuous phase introduction flow path can be arbitrarily controlled.

  By doing so, the particle diameter of the fine particles can be controlled by adjusting the merging angle of the dispersed phase and the continuous phase without changing the liquid feeding speed of the continuous phase and the dispersed phase. Conversely, even if the liquid feeding speed of the dispersed phase and the continuous phase varies somewhat, the particle size of the fine particles can be prevented from changing greatly.

  Examples of the present invention will be described below, and the embodiments of the present invention will be described in more detail. It is needless to say that the present invention is not limited to the following examples and can be arbitrarily changed without departing from the gist of the present invention.

  In the embodiment, one microchannel is formed on one microchannel substrate. However, in the case of mass production industrially, a large number of microchannels are formed on one microchannel substrate. Or by stacking a large number of formed micro flow path substrates.

(Example)
FIG. 6 shows a microchannel for generating fine particles according to an embodiment of the present invention. The microchannels are on Pyrex (registered trademark) glass of 70 mm × 20 mm × 1 t (thickness), and the widths of the continuous phase introduction channel 3, the dispersed phase introduction channel 5, and the discharge channel 7 corresponding to the microchannels are the same. In any case, the Y-shape is 220 μm, the depth is 80 μm, the aspect ratio of the micro flow path is 0.36, and the length of the discharge flow path 7 is 30 mm, and the continuous phase introduction flow path 3 and the dispersed phase introduction flow path 5 are One Y-shaped flow path having a merging portion where the angle 9 intersects at 44 degrees was formed. This Y-shaped microchannel was formed using general photolithography and wet etching.

  On the surface of the microchannel substrate 13 on which the microchannel is formed, on the surface having the microchannel, at positions corresponding to the fluid inlet (continuous phase inlet 2 and dispersed phase inlet 4) and the fluid outlet 8 of the microchannel. A glass cover body 14 having a thickness of 1 mm and a thickness of 70 mm × 20 mm previously provided with a small hole having a diameter of 0.6 mm using a mechanical processing means is thermally bonded, and as shown in FIG. A microchannel structure was fabricated. In this embodiment, the glass substrate is used for the micro-channel substrate and the cover body that form the micro-channel, but the present invention is not limited to this.

  Next, as shown in FIG. 7, the microparticle structure 15 for generating fine particles is held by a holder 16 or the like so that a liquid can be fed, and a Teflon (registered trademark) tube 18 having an inner diameter of 400 μm and a fillet joint 19 are attached to the holder. 16 was fixed. The other end of the Teflon (registered trademark) tube 18 was connected to the microsyringes 21 and 22. In this way, liquid can be sent to the micro-channel structure 15 for generating fine particles. Moreover, as shown in FIG. 7, the microwave irradiation apparatus 12 was installed in a part of Teflon (trademark) tube 18 connected from the discharge port 8, and the microparticle manufacturing apparatus was comprised.

  Next, a mixed solution of monomer (styrene), divinylbenzene, butyl acetate and benzoyl peroxide as a polymerization initiator is used as a dispersion phase for generating droplets that form fine particles, and a 3% aqueous solution of polyvinyl alcohol is used as a continuous phase. The solution was injected into the microsyringes 21 and 22, and the liquid was fed by the microsyringe pump 20. The liquid feeding flow rate is 2 μl / min for both the dispersed phase and the continuous phase. In a state where both the liquid feeding flow rates were stable, droplet generation as shown in FIG. 8 was observed at the junction where the dispersed phase and the continuous phase of the microchannel structure 15 for generating fine particles intersect. After the droplets were generated, the droplets were cured by the microwave irradiation device 12 installed in a part of the Teflon (registered trademark) tube 18 communicated from the discharge port 8. The microwave irradiation part is one having a microwave output of 600 W and a microwave irradiation magnetron frequency of 2.45 GHz. The length of the Teflon (registered trademark) tube irradiated with the microwave is 70 mm, and the droplet is The aqueous slurry of polyvinyl alcohol contained therein was continuously fed to set the microwave irradiation time to about 60 seconds, and the droplets were cured to produce fine particles. Observe the generated fine particles, measure the particle size of 100 fine particles, average the average particle size 200 μm, and the particle size dispersion, which is the value obtained by dividing the standard deviation of the particle size by the average particle size, is 5.8%. Very fine particles.

(Comparative example)
As a comparative example of the present invention, the same microchannel structure as that used in the example was used, and a fine particle production apparatus as shown in FIG. 9 was used. In the same manner as in the examples, a mixed solution of monomer (styrene), divinylbenzene, butyl acetate and benzoyl peroxide as a polymerization initiator is used as a dispersion phase for generating droplets that form fine particles, and polyvinyl alcohol 3 is used as a continuous phase. % Aqueous solution was injected into the microsyringes 21 and 22, and the microsyringe pump 20 was used for liquid feeding. The liquid feeding flow rate was 2 μl / min for both the dispersed phase and the continuous phase. Droplet generation as shown in FIG. 6 was observed at the junction where the dispersed phase and the continuous phase of the micro-channel structure 15 for fine particle generation intersect in a state where both liquid feeding flow rates were stable. After producing the droplets, 1 mL of an aqueous slurry of polyvinyl alcohol containing droplets in a beaker was collected through a Teflon (registered trademark) tube 18 communicating from the discharge port 8 as shown in FIG. Thereafter, the collected beaker was heated to 65 ° C. with a heater, and slowly stirred for about 1 hour so as not to break the generated droplets, thereby curing the droplets and generating fine particles. When the produced fine particles were observed in the same manner as in the Examples, the average particle size was 213 μm, and the particle size dispersion degree was 9.8%.

It is the schematic which shows the general microchannel for droplet generation. It is AA 'cross section in FIG. It is a BB 'cross section in FIG. It is the conceptual diagram which showed the method of hardening a droplet by microwave irradiation with the thin tube (Teflon (trademark) tube) connected with the discharge port of a microchannel structure. It is the conceptual diagram which showed the method of hardening a droplet by microwave irradiation in the discharge flow path of a microchannel structure. It is a conceptual diagram of the micro channel structure in the present invention. It is a conceptual diagram of the fine particle manufacturing apparatus in an Example. It is a figure which shows the droplet production | generation condition in an Example. It is a conceptual diagram of the microparticle manufacturing apparatus in a comparative example. It is a conceptual diagram of the micro channel in the present invention. It is a conceptual diagram which shows one of the aspects of the cross | intersection part of the microchannel in this invention. It is a conceptual diagram which shows one of the aspects of the cross | intersection part of the microchannel in this invention. It is CC 'cross section in FIG. It is a conceptual diagram which shows one of the aspects of the cross | intersection part of the microchannel in this invention. It is DD 'cross section in FIG. It is a conceptual diagram which shows one of the aspects of the cross | intersection part of the microchannel in this invention. It is EE 'cross section in FIG. It is a conceptual diagram which shows one of the aspects of the cross | intersection part of the microchannel in this invention. It is FF 'cross section in FIG.

Explanation of symbols

1: Micro-channel substrate 2: Continuous phase introduction port 3: Continuous phase introduction channel 4: Dispersed phase introduction port 5: Dispersed phase introduction channel 6: Junction section 7: Discharge channel 8: Discharge port 9: Angle 10: Microchannel 11: Microwave irradiation site 12: Microwave irradiation device 13: Microwave absorber 14: Cover body 15: Microchannel structure 16: Holder 17: Beaker 18: Teflon (registered trademark) tube 19: Fillet joint 20: Micro syringe pump 21: Micro syringe (continuous phase)
22: Micro syringe (dispersed phase)
23: Microwave irradiation

Claims (11)

The dispersed phase introduction port and the dispersed phase introduction channel for introducing the dispersed phase, the continuous phase introduction port and the continuous phase introduction channel for introducing the continuous phase, and the dispersed phase introduction channel and the continuous phase introduction channel intersect. A micro-channel structure including a discharge channel extending from an intersection to a discharge port, and a discharge port for discharging fine particles generated by the combination of a dispersed phase and a continuous phase in the discharge channel, and curing the fine particles An apparatus for producing fine particles comprising microwave irradiation means. 2. The fine particle manufacturing apparatus according to claim 1, wherein the microwave irradiation means irradiates the fine particles generated in the microchannel structure with microwaves. 2. The fine particle manufacturing apparatus according to claim 1, wherein the microwave irradiation means irradiates the fine particles discharged from the discharge port of the microchannel structure with microwaves. The fine particle manufacturing apparatus according to any one of claims 1 to 3, wherein a channel shape formed from the dispersed phase introduction channel, the continuous phase introduction channel, and the discharge channel is Y-shaped. 5. The fine particle production apparatus according to claim 4, wherein an angle at which the dispersed phase introduction channel and the continuous phase introduction channel intersect in the microchannel structure can be arbitrarily controlled. A method for producing fine particles, wherein a dispersed phase and a continuous phase are introduced into a minute flow path, and both are joined to produce fine particles, and then the produced fine particles are irradiated with microwaves to be cured. 7. The method for producing fine particles according to claim 6, wherein the particle diameter of the fine particles to be produced is controlled by changing the angle at which the flow path for introducing the dispersed phase and the flow path for introducing the continuous phase intersect. The method for producing fine particles according to claim 6 or 7, wherein the dispersed phase is a medium containing a raw material for gel production. The method for producing fine particles according to claim 6 or 7, wherein the continuous phase is a medium containing a dispersant for producing a gel. The method for producing fine particles according to claim 9, wherein the dispersant for producing the gel is polyvinyl alcohol. The method for producing fine particles according to any one of claims 6 to 10, wherein the apparatus for producing fine particles according to any one of claims 1 to 5 is used.

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