JP2006053060A - Fine particle manufacturing method, and micro flow passage structure therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micro flow passage structure capable of generating a large amount of fine liquid drops of uniform particle sizes having 10μm of average particle size in a micro flow passage, and having 10% or less of particle size dispersion degree, by an inexpensive device, and a liquid drop generating method using the same. <P>SOLUTION: In this fine particle generating method, a dispersion phase is fed out into the micro flow passage with a flowing continuous phase, through a micro space, the continuous phase is intruded in between the dispersion phase and a flow passage inner wall surrounding the dispersion phase, in the vicinity of a connection part between the micro space and the micro flow passage with the flowing continuous phase, and the dispersion phase generates the fine particles of a particle size having a cross-sectional area smaller than a cross-sectional area of the micro space in a tip of the substantially conical flow, when the one or more of substantially conical flows with the sharp tip are formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is the production of fine particles used in column fillers for separation / separation, fine particles used in microcapsules used in pharmaceuticals, enzyme-containing capsules, cosmetics, fragrances, display / recording materials, adhesives, agricultural chemicals, etc. The present invention relates to a micro flow channel structure that is suitably used for the purpose, and a method for producing fine particles using the same.

  In recent years, a fluid is introduced into a microchannel using a microchannel structure having a microchannel having a length of about several centimeters on a glass substrate of several cm square and a width and depth of sub-μm to several hundred μm. Research that produces fine particles by doing so has attracted attention.

  As one of the means for generating fine particles, two kinds of fluids having different interfacial tensions are introduced into a flow path where an intersection of the two kinds of fluids exists, and one fluid is sheared by the other. It has been reported that fine particles can be generated (see, for example, Patent Document 1). In addition to the solid fine particles, the fine particles referred to in the present invention are fine droplets, fine particles obtained by curing only the surface of the fine droplets (hereinafter referred to as “semi-cured”), semi-solid particles having high viscosity. Also includes fine particles.

  For example, as shown in FIG. 1, the technique disclosed in Patent Document 1 is a continuous phase introduction port (2) and a flow path for introducing a continuous phase (hereinafter referred to as a continuous phase introduction flow path (3)) to a substrate (1). Disperse phase introduction port (4), a flow path for introducing a disperse phase (hereinafter referred to as a disperse phase introduction flow path (5)), a flow path for discharging a disperse phase formed into microdroplets in a continuous phase (hereinafter referred to as a disperse phase) A fine channel structure having a T-shaped channel having a discharge channel (7) and a discharge port (8) and having a cover body (32) joined to the channel surface side of the substrate, With respect to the continuous phase flowing in the microchannel, the dispersed phase is discharged from the dispersed phase supply port in a direction intersecting the flow of the continuous phase, and the diameter of the dispersed phase is larger than the width of the supply channel of the dispersed phase by the shear stress of the continuous phase. Small micro droplets are obtained. Here, Patent Document 1 describes that the width of the continuous phase introduction channel and the width of the dispersed phase introduction channel are 100 μm, and the depth of the continuous phase introduction channel and the depth of the dispersed phase introduction channel are 100 μm. ing. Hereinafter, a portion where the introduced continuous phase and the dispersed phase intersect is referred to as an intersection (6). When the liquid feeding is performed by controlling the flow rates of the dispersed phase and the continuous phase using the technique described in Patent Document 1, it is possible to generate micro droplets of several μm to several hundreds of μm. It is described that it is possible to control the particle size of the generated fine droplets by controlling the flow rate. Regarding the particle size of the obtained fine droplets, in Patent Document 1, the liquid feeding pressure of the dispersed phase is fixed to 2.45 kPa, and the liquid feeding pressure of the continuous phase is changed to 4.85 to 5.03 kPa. It is shown that microdroplets with a particle size of ˜25 μm are obtained. However, it is generally very difficult to produce microdroplets having a particle size of less than 10 μm and a good degree of particle size dispersion using only the shear stress of the fluid.

As a second method for producing fine particles, when the dispersed phase passes through the non-circular through holes formed in the intermediate plate and is pushed out to the continuous phase, the dispersed phase is made minute by the uneven shear stress from the continuous phase. There is a method for forming droplets (see, for example, Patent Document 2). A schematic diagram of this method is shown in FIG. 2, and a cross-sectional view taken along the line AA 'of FIG. 2 is shown in FIG. In this example, a large number of non-circular through holes (13) of the order of submicron to several microns are formed in the intermediate plate (12), the first plate (14) is provided on the intermediate plate, and the second plate is provided below. Plates (15) are mounted at spaced intervals, the dispersed phase (27) flows between the first plate and the intermediate plate, and the continuous phase (33) flows between the second plate and the intermediate plate. When the dispersed phase passes through the non-circular through-holes in the intermediate plate and is pushed out to the continuous phase, the through-holes are non-circular, so that the dispersed phase rapidly undergoes microdroplets due to uneven shear stress from the continuous phase. Is done. Further, the number of through holes formed in the intermediate plate in order to mass-produce micro droplets is, for example, 1000 / cm ² or more. However, also a number forming a non-circular through hole of the order of several microns 1000 / cm ² or more from the submicron order on the intermediate plate regardless of the material, using a large-scale apparatus such as an electron beam irradiation and high-density plasma etching This method is very expensive and is not suitable for practical production equipment.

  In addition, as a third method for generating micro droplets, a micro space sandwiched between two channels (hereinafter referred to as channel A and channel B) and communicating with the two channels, A fluid to be converted into microdroplets is sent from one channel A, and after the fluid is drawn into the microspace by capillary action, the fluid remaining in the channel A is removed, and a volume corresponding to the volume of the microspace is obtained. Attempts have been made to generate microdroplets (see, for example, Patent Document 3).

  As shown in FIG. 4, the technique disclosed in Patent Document 3 includes a first flow path A (9) and a second flow path B (10) that are each extended in a predetermined direction, a flow path A and A flow path A that opens in each flow path wall of the flow path B and connects the flow path A and the flow path B, and a third minute space C (11) that is thinner than the thickness of the flow path B. After the liquid introduced into the channel A is drawn into the minute space C by capillary action through the opening of the minute space C opened in the channel wall of the channel A, the liquid remaining in the channel A is removed. The microdroplet having a volume corresponding to the volume of the microspace C is generated and sent to the flow path B.

In Patent Document 3, the volume of the minute space C is substantially on the order of nL (nanoliter), and there is a description in the examples that fine droplets of a 5 nL glucose aqueous solution are generated. This is about 200 μm in terms of particle size. Furthermore, in order to generate micro droplets having a small average particle size, the volume of the micro space C needs to be reduced. If the volume of the micro space C is less than 0.5 pL (picoliter), the average particle size is less than 10 μm. It is computationally possible to produce a microdroplet. However, the cross-sectional area of 0.5 pL is about 8 μm ³ assuming a 0.5 pL cube.

  However, when microdroplets are generated in the manner of Patent Document 3, there is a problem that the microdroplet generation speed is slow. In fact, in the example of Patent Document 3, the material for generating the microdroplets is not continuously flowed, but the flow path A is used to store the liquid only in the microspace C after flowing the liquid that is the raw material for the microdroplets. In order to eliminate the liquid that is the raw material of the fine droplets from the liquid and to discharge the liquid stored in the minute space C to the flow path B, it is necessary to send another fluid to the flow path A. One minute droplet is generated by the operation. Therefore, in the method of Patent Document 3, it is possible to generate micro droplets having an average particle size of about several μm and a degree of dispersion of less than 10%. However, since the generation speed is slow, the actual business scale is reduced. It was very difficult to apply to the corresponding mass production.

International Publication WO02 / 068104 Pamphlet Japanese Patent No. 3511238 JP 2002-357616 A

  As described above, the conventional technology for producing fine particles by fluid shear stress or capillary action produces low-priced particles having an average particle size of less than 10 μm and a uniform particle size of less than 10%. It was very difficult to produce in large quantities with the equipment. Here, the particle size dispersion is defined as a value obtained by dividing the standard deviation of the particle size by the average value of the particle sizes (hereinafter referred to as the average particle size), and in the present invention, the particle size dispersion is good. Means that the particle size dispersion is less than 10%.

  The present invention has been made in view of the above problems, and a large amount of fine particles having a uniform particle diameter having an average particle diameter of less than 10 μm and a particle size dispersion of less than 10% in a microchannel can be obtained with a cheaper apparatus. It is an object of the present invention to provide a micro flow channel structure that can be generated in a simple manner and a fine particle generation method using the same.

  As a means for solving the above problems, the present invention provides a method in which a dispersed phase is extruded through a minute space into a microchannel through which a continuous phase flows, and fine particles of the dispersed phase are generated by self-particulation of the dispersed phase and shear stress of the continuous phase. In addition, in the vicinity of the connection portion between the minute space and the minute channel through which the continuous phase flows, the continuous phase enters between the dispersed phase and the inner wall of the channel surrounding the dispersed phase, and the dispersed phase has one or more substantially cones with sharp points. Provided is a fine particle production method for producing fine particles having a particle size having a cross-sectional area smaller than a cross-sectional area of a minute space at a substantially conical tip when a flow is formed. The present invention also includes a first microchannel substrate and a second microchannel substrate in order to embody the fine particle generation method, and the first microchannel substrate has a dispersed phase and a continuous phase. One or more microchannels that flow without intersecting each other are provided, and the second microchannel substrate is provided with one or more microspaces for connecting the microchannels through which the dispersed phase and the continuous phase flow, The micro-channel surface of the micro-channel substrate and the micro-space surface of the second micro-channel substrate are bonded to each other so that the width and / or depth of the micro-space is a dispersed phase and a continuous phase. Provided is a microchannel structure in which one or more inner wall surfaces of a microspace are curved in a substantially convex shape toward the inside of the microspace, wherein the microchannel is smaller in width and / or depth than the microchannel. Is. As a result, the above-mentioned problems with the prior art could be solved, and the present invention was finally completed. Hereinafter, the present invention will be described in detail.

  In the fine particle production method of the present invention, the dispersed phase is pushed through the minute space through the minute channel through which the continuous phase flows. And having a cross-sectional area smaller than the cross-sectional area of the minute space at the substantially conical tip when one or more substantially conical flows with a sharp point are formed. This is a fine particle production method for producing fine particles having a particle diameter. In general, when the shear stress of the continuous phase acts on the dispersed phase, a phenomenon in which the continuous phase enters a part of the dispersed phase occurs. At this time, when the liquid feeding speed and the liquid feeding pressure of the dispersed phase and the continuous phase are adjusted, the dispersed phase forms one or more substantially conical flows with sharp points, and the tip of the dispersed phase is smaller than the cross-sectional area of the minute space. Fine particles having a particle size having an area are formed. By using such a fine particle production method, fine particles having a particle size on the order of submicron to several microns can be produced.

  The fine particle production method of the present invention is a fine particle production method in which a dispersed phase is extruded through a minute space into a minute flow channel through which a continuous phase flows, and the dispersed phase self-particles and the dispersed phase fine particles are produced by shear stress of the continuous phase.

  In general, self-particle formation is caused by interfacial tension, and shear of the dispersed phase is caused by shear stress of the continuous phase. Therefore, in addition to self-particle formation due to interfacial tension, shear stress due to the flow of the continuous phase works, so that the particle size is smaller than when generating fine particles from the dispersed phase only by interfacial tension or only by shear stress of the continuous phase. Since it becomes easy to produce fine particles, smaller fine particles can be produced at a higher production rate.

  The microchannel structure of the present invention is a microchannel structure composed of a first microchannel substrate and a second microchannel substrate, and is dispersed on the first microchannel substrate. One or more micro flow channels each flowing without intersecting each other and the continuous phase are provided, and the second micro flow channel substrate has one or more micro spaces for connecting the micro flow channels through which the dispersed phase and the continuous phase flow. And a microchannel structure in which the microchannel surface of the first microchannel substrate and the microspace surface of the second microchannel substrate face each other and are bonded together.

  In this way, the microchannel structure is formed by bonding two microchannel substrates to each other so that the first microchannel substrate and the second microchannel substrate can be separated from each other by general machining. It is only necessary to process the width and depth of the channel as a flow path from submicron order to micron order by techniques such as photolithography and wet etching or dry etching, bead blasting, etc. There is no need to form a large number of through holes. Moreover, what is necessary is just to form a through-hole of about several millimeters by machining using a drill etc. in the location which introduce | transduces and discharges a dispersed phase and a continuous phase as processing locations other than a flow path. Therefore, a large number of non-circular through-holes of submicron to several tens of microns are formed by a method using a large apparatus such as electron beam irradiation or high-density plasma etching in order to generate fine particles having a particle size of less than several μm. It becomes possible to process very cheaply compared to

  Further, when the material of the microchannel structure is resin, a mold having a convex portion corresponding to the channel of the first microchannel substrate and the channel of the second microchannel substrate If a mold having a convex portion corresponding to is prepared, each microchannel substrate can be formed by molding such as injection molding using the mold. In this case, through-holes of about several millimeters corresponding to locations where the dispersed phase and continuous phase are introduced and discharged may be formed simultaneously with the flow path. This makes it possible to produce a microchannel structure that generates fine particles at a lower cost.

  The flow path described in the present invention means a micro flow path unless otherwise specified. In general, a microchannel has a channel width of 1 μm to 500 μm, preferably 5 μm to 200 μm, a channel depth of 0.1 μm to 200 μm, preferably 1 μm to 50 μm, and the length of the channel. The thickness means a flow path of 1 μm to 50 cm, preferably 10 μm to 5 cm.

  The material of the microchannel substrate constituting the microchannel structure in the present invention is, for example, a substrate material such as glass, quartz, ceramic, silicon, metal, resin, etc. There is no particular limitation as long as the width and depth of the groove as the flow path can be processed from submicron order to micron order by techniques such as etching, dry etching, bead blasting and general machining. In addition, as a method for joining the micro-channel substrates, when the substrate material is ceramics or metal, soldering or adhesive is used, or when the substrate material is glass, quartz, or resin, it is hundred to several hundreds of degrees. A bonding method suitable for each substrate material is used, such as thermal bonding by applying a load at a high temperature, or when the substrate material is silicon, by activating the surface by washing and bonding at room temperature.

  The microchannel structure according to the present invention is characterized in that the width and / or depth of the microspace is smaller than the width and / or depth of the microchannel through which the dispersed phase and the continuous phase flow. It is. In this way, at least one of the width and / or depth of the minute space is made smaller than the width and / or depth of the minute channel for flowing the dispersed phase and the continuous phase, and the dispersed phase is pushed out of the minute space into the continuous phase. Sometimes, a large interfacial tension is likely to act on the dispersed phase interface, so that the dispersed phase is easily made into self-particles, and a shear stress of the continuous phase is increased, so that the dispersed phase is easily sheared.

In general, the force S [N / m ² ] based on the interfacial tension is expressed by the following (formula 1). Here, T [N / m] is the interfacial tension, and D [m] is the representative length.
S = T / D (Formula 1)
Further, the shear stress V [N / m ² ] is expressed by the following (formula 2). Here, μ [Pa · s] is a viscosity coefficient, v is a linear velocity of the fluid [m / s], and D [m] is a representative length.
V = μv / D (Formula 2)
Here, as the representative length D, the one having the smaller value of the width or depth of the minute space smaller than the width or depth of the minute flow path for flowing the dispersed phase and the continuous phase can be applied. The smaller the value, the larger the interfacial tension and the shear stress, and the easier the self-particle formation by the interfacial tension and the particle formation by the shear stress occur.

  Furthermore, in the microchannel structure according to the present invention, in the microspace provided in the second microchannel substrate, one or more inner wall surfaces of the microspace are curved in a substantially convex shape toward the inside of the microspace. This is a microchannel structure. By doing so, the above-described representative length D is further reduced, and therefore, when the dispersed phase is pushed out from the minute space to the continuous phase, interfacial tension is more likely to act on the dispersed phase interface, and the dispersed phase becomes more self-particles. And the continuous phase is more easily sheared by the continuous phase. In order to produce a structure in which one or more inner wall surfaces of a minute space are curved in a substantially convex shape toward the inner side of the minute space, for example, when glass or resin is used as a material, the first minute channel substrate and When joining the second microchannel substrate by thermal bonding, a part of the inner wall of the microspace is directed toward the inside of the microspace by joining the part of the microspace with a larger load than other parts. It can be produced by distortion.

  The microchannel structure of the present invention is a microchannel structure in which two or more of the microchannel structures described above are stacked. By adopting such a configuration, a plurality of two-dimensionally and three-dimensionally configured channel configurations each including a channel through which a dispersed phase flows, a channel through which a continuous phase flows, and a minute space connecting the dispersed phase and the continuous phase are formed. Thus, a large amount of fine particles can be generated. In addition, the flow path through which the dispersed phase flows and the flow path through which the continuous phase flow are all connected to each flow path, and the fluid introduction port and the fluid discharge port communicated with the flow path through which the dispersed phase flows, and the continuous phase flows. A configuration may be adopted in which one fluid introduction port and one fluid discharge port each communicating with the flow path are provided.

  Further, in the microchannel structure of the present invention, the lyophilicity of the inner wall of the microchannel through which the dispersed phase flows and the inner wall of the microspace is different from that of the inner wall of the microchannel through which the continuous phase flows. More preferred. By doing so, the dispersed phase easily enters into the minute space, and fine particles are easily formed when being pushed out into the continuous phase. For example, it is possible to generate hydrophobic microdroplets by making the inner wall of the microchannel through which the dispersed phase flows and the inner wall of the microspace hydrophobic, and making the inner wall of the microchannel through which the continuous phase flows hydrophilic. It becomes easy. Conversely, by making the inner wall of the microchannel through which the dispersed phase flows and the inner wall of the microspace hydrophilic, and making the inner wall of the microchannel through which the continuous phase flows hydrophobic, hydrophilic microdroplets can be generated. It becomes easier.

  Hereinafter, the present invention will be described in more detail with reference to the drawings.

  FIG. 5 is a conceptual diagram for explaining the microchannel structure of the present invention, FIG. 6 is a sectional view taken along line BB ′ of FIG. 5, and FIG. 7 is CC ′ of FIG. A cross-sectional view is shown. 8 to 11 are conceptual diagrams for explaining the principle of the present invention.

  As shown in FIGS. 5 and 6, the channel A (9), the channel B (10), and the minute space C (11) are bridged between the two channels A and B. It has become such an arrangement. In this case, as shown in FIG. 6, at least one of the width and / or depth of the opening B (17) on the flow path B side of the minute space C is the width and / or depth of the flow path B. It is preferable that it is smaller than this. Further, as shown in FIG. 7, it is preferable that one or more inner wall surfaces of the minute space C are curved in a substantially convex shape toward the inner side of the minute space C. By doing so, when the dispersed phase is pushed out from the minute space C to the flow path B, as shown in (Equation 1) described above, a larger interfacial tension is applied to the dispersed phase to disperse due to the interfacial tension. As a result, self-particulation of the phase is likely to occur, and as shown in the above-described (Equation 2), a larger shear stress is applied to the dispersed phase, so that the dispersed phase is easily atomized by shearing.

  In the present invention, the state of microdroplet generation differs greatly depending on the speed at which the dispersed phase is fed and the speed at which the continuous phase is fed. This state will be described with reference to FIGS. 8 to 11, the dispersed phase and the continuous phase are shown flowing from the right to the left in the respective flow path diagrams.

  FIG. 8 is a conceptual diagram showing a case where the dispersed phase is pushed out as a laminar flow (18) when pushed into the continuous phase. FIG. 9 also shows that when the dispersed phase (27) is pushed out into the continuous phase (33), fine particles (19) having a particle size having a cross-sectional area larger than the cross-sectional area of the laminar flow (18) or the minute space C (11). It is the conceptual diagram which showed the case where it forms. In the case of FIGS. 8 and 9, the continuous phase may enter part of the dispersed phase in the minute space C (11).

  FIG. 10 is a conceptual diagram showing a case where the fine particles (19) are intermittently generated only by the shear stress of the continuous phase when the dispersed phase (27) is pushed out to the continuous phase (33). In this case, the continuous phase enters a part of the dispersed phase of the minute space C (11), and more strictly, the continuous phase of the dispersed phase of the minute space C (11) continues to a part on the upstream side. Phase enters and fine particles are generated.

  Further, FIG. 11 shows that when the dispersed phase (27) is extruded into the continuous phase (33), the phenomenon that the dispersed phase self-particles due to the interfacial tension and the phenomenon that the dispersed phase is sheared due to the shear stress of the continuous phase simultaneously. It is the conceptual diagram which showed the case where it wakes up and a microparticle is produced | generated continuously continuously. The method for producing fine particles in the present invention corresponds to the case of producing fine particles in the state of FIG.

  As shown in FIG. 11, when the dispersed phase (27) is extruded into the continuous phase (33), there are a phenomenon in which the dispersed phase is self-particled by the interfacial tension and a phenomenon in which the dispersed phase is sheared by the shear stress of the continuous phase. When it occurs at the same time, the continuous phase enters between the inner wall of the flow path surrounding the dispersed phase and the dispersed phase in the vicinity (20) of the small space C (11) and the flow path B (10) through which the continuous phase flows. Is deformed into one or more substantially conical shapes (21) having sharp points, and fine particles (19) are generated at the substantially conical tips.

  FIG. 12 is a diagram showing the flow of a fluid according to an embodiment of the present invention. The flow is substantially conical due to the phenomenon that the dispersed phase self-particles due to the interfacial tension and the phenomenon that the dispersed phase is sheared due to the shear stress of the continuous phase. It can be seen that a flow of dispersed phase is formed. FIG. 13 schematically shows a state in which a dispersed phase such as a portion surrounded by a line in FIG. 12 forms a substantially conical flow, and FIG. 14 shows that the dispersed phase has two substantially conical shapes. A mode that a flow is formed is shown typically.

  In general, when the shear stress of the continuous phase acts on the dispersed phase, a phenomenon occurs in which the continuous phase enters a part of the dispersed phase. When the liquid feeding speed and the liquid feeding pressure of the dispersed phase and the continuous phase are adjusted, the continuous phase enters between the inner wall of the flow path surrounding the dispersed phase and the dispersed phase, and the dispersed phase is pointed 1 near the connecting portion (20). Fine particles having a cross-sectional area smaller than the cross-sectional area of the minute space C are stably formed at the tip thereof by deforming into the above substantially conical shape. By using such a fine particle generation method, it is possible to generate fine particles having a particle size on the order of submicron to several microns smaller than the cross-sectional area of the minute space C.

  In the fine particle production method of the present invention, the dispersed phase is pushed through the minute space through the minute channel through which the continuous phase flows, and the inner wall of the channel surrounding the dispersed phase in the vicinity of the connection portion between the minute space and the minute channel through which the continuous phase flows. When the continuous phase enters between the first and second dispersed phases, and the one or more substantially conical flows having a sharp point are formed in the dispersed phase, a section smaller than the cross-sectional area of the minute space is formed at the substantially conical tip. This is a fine particle production method for producing fine particles having a particle size having an area. By using such a fine particle production method, a large amount of fine particles of submicron order to several micron order can be produced.

  The fine particle production method of the present invention is a fine particle production method in which a dispersed phase is pushed through a minute space through a minute channel through which a continuous phase flows, and the dispersed phase self-particles and the continuous phase shear stress generate fine particles of the dispersed phase. is there. By doing this, in addition to self-particle formation due to interfacial tension, shear stress due to the flow of the continuous phase works, compared to the case where fine particles are generated from the dispersed phase only by interfacial tension or by continuous phase shear stress. Since it becomes easier to produce fine particles, a larger amount of smaller fine particles can be produced at a faster production rate.

  The microchannel structure of the present invention is a microchannel structure composed of a first microchannel substrate and a second microchannel substrate, and the first microchannel substrate has a dispersed phase. One or more microchannels each flowing without intersecting the continuous phase are provided, and the second microchannel substrate has one or more microspaces for connecting the dispersed phase and the microchannel through which the continuous phase flows. A microchannel structure that is provided and has a microchannel surface of a first microchannel substrate and a microspace surface of a second microchannel substrate facing each other and bonded together. In this way, the microchannel structure is formed by bonding two microchannel substrates, so that the first microchannel substrate and the second microchannel substrate can be combined with general machining or photolithography. It is only necessary to process the width and depth of the groove as the flow path by sub-micron order to several tens of micron order by wet etching or dry etching, bead blasting, and so on. Compared with forming a large number of non-circular through holes of micron order to several micron order by a method using a large apparatus such as electron beam irradiation or high-density plasma etching, it can be processed at a very low cost.

  The microchannel structure according to the present invention is characterized in that the width and / or depth of the microspace is smaller than the width and / or depth of the microchannel through which the dispersed phase and the continuous phase flow. It is. In this way, by setting at least one or more of the width and / or depth of the microspace to be smaller than the width and / or depth of the microchannel through which the dispersed phase and continuous phase flow, the dispersed phase is pushed out of the microspace into the continuous phase. When a large interfacial tension is applied to the dispersed phase interface, the dispersed phase easily becomes self-particles, and the shear stress of the continuous phase becomes larger, so that the dispersed phase is easily sheared.

  Furthermore, in the microchannel structure according to the present invention, in the microspace provided in the second microchannel substrate, one or more inner wall surfaces of the microspace are curved in a substantially convex shape toward the inside of the microspace. It is the microchannel structure characterized by having. By doing so, when the dispersed phase is pushed out from the micro space to the continuous phase, the interfacial tension at the dispersed phase interface is further increased, so that the dispersed phase is more likely to be self-particles, and the shear stress of the continuous phase is further increased. It becomes easy to shear a dispersed phase more by becoming large.

  A microchannel structure according to the present invention is a microchannel structure characterized in that two or more of the microchannel structures described above are stacked. By adopting such a configuration, a plurality of two-dimensionally and three-dimensionally arranged channel configurations including a channel through which the dispersed phase flows, a channel through which the continuous phase flows, and a minute space connecting the dispersed phase and the continuous phase are arranged. Therefore, a large amount of fine particles can be generated.

An example of the embodiment of the present invention will be described below. Needless to say, the present invention is not limited to the following embodiments, and can be arbitrarily changed without departing from the gist of the invention.
(Example)
FIG. 15 shows a schematic diagram of a microchannel structure in an embodiment of the present invention. As the first microchannel substrate (23), a channel A (9) and a channel B (10) were formed on Pyrex (registered trademark) glass of 70 mm × 20 mm × 1 t (thickness). In addition, as a second microchannel substrate (22), a microspace C (11) was formed on Pyrex (registered trademark) glass of 70 mm × 20 mm × 1 t (thickness). The channel A, the channel B, and the minute space C were formed by general photolithography and wet etching. The micro space C was formed at a position where the channel A and the channel B were connected and connected when the first micro channel substrate and the second micro channel substrate were bonded together. Here, the channel width of the channel A is 442 μm, the channel depth is 21.7 μm, and the channel length is 6 cm. The channel B has a channel width of 242 μm, a channel depth of 21.7 μm, and a channel length of 6 cm. In the minute space C, the width of the opening A (16) communicating with the flow path A is 33.4 μm, the width of the opening B (17) communicating with the flow path B is 33.4 μm, the length is 300 μm, and the depth Was 21.7 μm.

  Further, as shown in FIG. 15, the fluid inlet A (28) and the fluid outlet A (29) for the channel A, and the fluid inlet B (30) and the fluid outlet B (31) for the channel B A through hole having a diameter of 1 mm was formed at a predetermined position of the two microchannel substrates. The first microchannel substrate and the twenty-first microchannel substrate were joined by general thermal bonding to produce a microchannel structure (34) as shown in FIG.

  Next, as shown in FIG. 17, the fluid inlet A (28) and the fluid outlet A (29) for the channel A of the microchannel structure (34), and the fluid inlet B (30) for the channel B A tube (36) made of Teflon (registered trademark) was connected so that the fluid could be introduced into and discharged from the fluid outlet B (31). A tube made of Teflon (registered trademark) has an outer diameter of 0.9 mm, an inner diameter of 200 μm, and a length of 20 cm. The syringe pump A (26) containing the dispersed phase (27) was connected to the Teflon (registered trademark) tube on the fluid inlet side for the channel A. A syringe pump B (25) containing a continuous phase (33) was connected to the Teflon (registered trademark) tube on the fluid inlet side for the channel B.

  When producing actual microdroplets, a 3% volume ratio polyvinyl alcohol aqueous solution was used for the continuous phase, and a mixed solution of monomer (styrene), divinylbenzene, butyl acetate and benzoyl peroxide was used for the dispersed phase.

  First, the continuous phase (33) is introduced into the flow path B (10) at a liquid feed rate of 0.8 μL / min, and the dispersed phase (27) is fed into the flow path A (9) at 1.0 μL / min. Introduced at liquid speed. In this case, microdroplets are not generated in the opening B (17) serving as the connection portion of the continuous phase through the microspace C (11), and the dispersed phase is laminar in the flow path B (10) through which the continuous phase flows. It flowed as (18).

  Next, the continuous phase (33) is introduced into the flow path B (10) at a liquid feed rate of 0.8 μL / min, and the dispersed phase (27) is introduced into the flow path A (9) at 0.8 μL / min. Introduced at the feeding speed. In this case, a laminar flow (18) is formed in the opening B (17) serving as a connection portion of the continuous phase through the minute space C (11), or the laminar flow is sheared in the middle, and the minute space C (11). Microdroplets (24) with a particle size having a cross-sectional area greater than FIG. 9 shows a conceptual diagram of how micro droplets are generated under the above liquid feeding conditions. The generated fine droplets were collected in the sample bottle (35), but the variation in particle size was large, and the average particle size and the particle size dispersion could not be measured.

  Next, the continuous phase (33) is introduced into the flow path B (10) at a liquid feed rate of 0.8 μL / min, and the dispersed phase (27) is added to the flow path A (9) at 0.05 μL / min. The liquid droplets were introduced at a liquid feeding speed, and microdroplets (24) were generated at the opening B (17) serving as a continuous phase connecting portion through the microspace C (11). FIG. 10 is a conceptual diagram showing how micro droplets are generated under the above-mentioned liquid feeding conditions. The generated microdroplets were collected in the sample bottle (35), and when 100 microdroplets were observed with a microscope, microdroplets with an average particle size of 15 μm and a particle size dispersion of 14.2% were generated. We were able to.

  Next, the continuous phase (33) is introduced into the flow path B (10) at a liquid feed rate of 0.05 μL / min, and the dispersed phase (27) is added to the flow path A (9) at 2.0 μL / min. The liquid droplets were introduced at a liquid feeding speed, and microdroplets (24) were generated at the opening B (17) serving as a continuous phase connecting portion through the microspace C (11). FIG. 18 is a conceptual diagram showing how micro droplets are generated under the above liquid feeding conditions. The generated microdroplets were collected with a sample bottle (35), and 100 microdroplets were observed with a microscope. As a result, microdroplets with an average particle size of 9.8 μm and a particle size dispersion degree of 9.8% were obtained. Could be generated.

It is a conceptual diagram of the T-shaped flow path which produces | generates microparticles | fine-particles by the shear of a continuous phase. It is a conceptual diagram of the microchannel structure which produces | generates microparticles | fine-particles by a through-hole type structure. FIG. 3 is a cross-sectional view taken along line A-A ′ in FIG. 2. It is a conceptual diagram of the microchannel structure which produces | generates the microparticles | fine-particles of the volume according to the volume of microspace. It is a conceptual diagram for demonstrating the microchannel structure of this invention. It is B-B 'sectional drawing in FIG. FIG. 6 is a cross-sectional view taken along C-C ′ in FIG. 5. It is a 1st conceptual diagram explaining the principle of this invention. It is a 2nd conceptual diagram explaining the principle of this invention. It is a 3rd conceptual diagram explaining the principle of this invention. It is a 4th conceptual diagram explaining the principle of this invention. It is a figure which shows the flow of the fluid by the principle of this invention. It is a conceptual diagram (schematic diagram) explaining the principle of the present invention. It is a conceptual diagram (schematic diagram) explaining the principle of the present invention. It is the schematic of the microchannel substrate which comprises the microchannel structure in the Example of this invention. It is the schematic of the microchannel structure in the Example of this invention. It is a conceptual diagram of the experiment form in the Example of this invention. It is a conceptual diagram explaining the state of the droplet production | generation in the Example of this invention.

Explanation of symbols

1: Substrate 2: Continuous phase introduction port 3: Continuous phase introduction channel 4: Dispersed phase introduction port 5: Dispersed phase introduction channel 6: Intersection 7: Discharge channel 8: Discharge port 9: Channel A
10: Channel B
11: Microspace C
12: Intermediate plate 13: Through hole 14: First plate 15: Second plate 16: Opening A
17: Opening B
18: Laminar flow 19: Fine particle 20: In the vicinity of the connection part 21: Conical shape 22: First microchannel substrate 23: Second microchannel substrate 24: Microdroplet 25: Syringe pump B
26: Syringe pump A
27: Dispersed phase 28: Fluid inlet A
29: Fluid outlet A
30: Fluid inlet B
31: Fluid outlet B
32: Cover body 33: Continuous phase 34: Microchannel structure 35: Sample bottle 36: Tube

Claims (6)

A disperse phase is pushed through a minute space through a minute channel through which the continuous phase flows, and in the vicinity of the connecting portion between the minute space and the minute channel through which the continuous phase flows, the inner wall of the channel surrounding the disperse phase and the disperse phase; Fine particles having a particle size that have a cross-sectional area that is smaller than the cross-sectional area of the minute space at the tip of the substantially conical shape when one or more substantially conical flows having a sharp point in the dispersed phase are formed. A method for producing fine particles, characterized in that 2. The method for producing fine particles according to claim 1, wherein the dispersed phase is extruded through a minute space through a minute channel through which the continuous phase flows, and the dispersed phase is self-particulated and the dispersed phase fine particles are produced by shear stress of the continuous phase. . A microchannel structure including a first microchannel substrate and a second microchannel substrate, wherein a dispersed phase and a continuous phase flow through the first microchannel substrate without crossing each other. One or more microchannels are provided, respectively, and the second microchannel substrate is provided with one or more microspaces for connecting the microchannels through which the dispersed phase and the continuous phase flow, and the first microchannel The micro-channel surface of the micro-channel substrate and the micro-space surface of the second micro-channel substrate are bonded to each other so that the width and / or depth of the micro-space allows the dispersed phase and the continuous phase to flow. A microchannel structure for generating fine particles, characterized by being smaller than the width and / or depth of the microchannel. 4. The micro space provided in the second micro channel substrate, wherein one or more inner wall surfaces of the micro space are curved in a substantially convex shape toward the inside of the micro space. 2. A microchannel structure according to 1. The microchannel structure according to claim 3 or 4, wherein two or more microchannel structures are stacked. The material of the said microchannel structure is resin, The microchannel structure in any one of Claims 3-5 characterized by the above-mentioned.

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