Process for producing emulsion and microcapsules and apparatus therefor

A process and apparatus for rapidly producing an emulsion and microcapsules in a simple manner. A dispersion phase is ejected from a dispersion phase-feeding port toward a continuous phase flowing in a microchannel such that flows of the dispersion phase and the continuous phase cross each other, thereby obtaining microdroplets, formed by the shear force of the continuous phase, having a size smaller than the width of the channel for feeding the dispersion phase.

TECHNICAL FIELD

The present invention relates to a process and apparatus for producing a microemulsion and microcapsules in water, oil, and chemically inert liquid.

BACKGROUND ART

Conventionally, apparatuses for producing a microemulsion (containing microspheres) and microcapsules have been used in steps of manufacturing chemicals and some processes have been proposed. There are the following processes (see, for example, PCT Japanese Translation Patent Application Publication No. 8-508933): a process in which a second solution is dropped in a first solution, a process in which a first solution is dropped in the air from the inside portion of a double tube and a second solution is dropped from the outside portion thereof, and so on. Among processes for scattering droplets in the air, there is a process for ejecting droplets using piezoelectric elements used for inkjet printers and so on.

On the other hand, a technique in which monodispersed microdroplets are prepared with laboratory equipment is disclosed in Japanese Unexamined Patent Application Publication No. 2000-84384. However, in this technique, there is a problem in that the rate of preparing such microdroplets is low and the microdroplets cannot be covered with surfactants or microcapsule shells. Furthermore, only microdroplets having a diameter three times larger than the width of microchannels can be prepared.

SUMMARY OF THE INVENTION

In view of the above situation, it is an object of the present invention to provide a process and apparatus for rapidly producing an emulsion and microcapsules in a simple manner.

In order to achieve the above object, the present invention provides the following methods and apparatuses.

(1) A process for producing an emulsion includes a step of ejecting a dispersion phase from a dispersion phase-feeding port toward a continuous phase flowing in a microchannel in such a manner that flows of the dispersion phase and the continuous phase cross each other, whereby microdroplets are formed by the shear force of the continuous phase and the size of the microdroplets is controlled.

(2) A process for producing microcapsules includes a step of feeding a shell-forming phase and a content-forming phase to a continuous phase flowing in a microchannel, in such a manner that flows of the shell-forming phase and the content-forming phase join the flow of the continuous phase, to obtain microcapsules, wherein the shell-forming phase is fed from positions upstream to positions for feeding the content-forming phase in such a manner that the shell-forming phase forms a thin layer.

(3) A process for producing an emulsion includes a step of ejecting a dispersion phase toward the junction of flows of continuous phases flowing in microchannels extending in the directions opposite to each other, in such a manner that the flow of the dispersion phase joins the flows of the continuous phases, to obtain microdroplets.

(4) A process for producing microcapsules includes a step of feeding a content-forming phase to first and second continuous phases flowing in first and second microchannels extending in the directions opposite to each other, in such a manner that the flow of the content-forming phase joins the flows of the first and second continuous phases, to form microdroplets for forming contents; and then feeding a shell-forming phase to third and fourth continuous phases flowing in third and fourth microchannels, in such a manner that the flow of the shell-forming phase joins the junction of flows of the third and fourth continuous phases, to form microdroplets for forming shells to obtain microcapsules.

(5) A process for producing an emulsion includes a step of allowing flows of a first continuous phase and a dispersion phase to join together at a first junction to form a two-phase flow and then allowing the two-phase flow, consisting of the flows of the first continuous phase and the dispersion phase joined together, to join a flow of a second continuous phase at a second junction to form an emulsion containing the dispersion phase.

(6) A process for producing microcapsules includes a step of allowing flows of a first continuous phase and a dispersion phase to join together at a first junction to form microdroplets and then allowing the flow of the first continuous phase containing the microdroplets to join a flow of a second continuous phase at a second junction to form microcapsules containing the first continuous phase containing the microcapsules.

(7) An apparatus for producing an emulsion includes means for forming a continuous phase flowing in a microchannel, means for feeding a dispersion phase to the continuous phase in such a manner that flows of the continuous phase and the dispersion phase cross each other, dispersion phase-ejecting means for ejecting the dispersion phase from a dispersion phase-feeding port, and means for forming microdroplets by the shear force of the continuous phase to control the size of the microdroplets.

(8) An apparatus for producing microcapsules includes means for forming a continuous phase flowing in a microchannel, means for feeding a shell-forming phase and a content-forming phase to a dispersion phase in such a manner that flows of the shell-forming phase and content-forming phase join the flow of the continuous phase, and means for feeding the shell-forming phase from positions upstream to positions for feeding the content-forming phase in such a manner that shell-forming phase forms a thin layer.

(9) An apparatus for producing an emulsion includes means for forming continuous phases flowing in microchannels extending in the directions opposite to each other; and means for ejecting a dispersion phase toward the junction of flows of the continuous phases, in such a manner that the flow of the dispersion phase joins the flows of the continuous phases, to obtain microdroplets.

(10) An apparatus for producing microcapsules includes means for feeding a content-forming phase to first and second continuous phases flowing in first and second microchannels extending in the directions opposite to each other, in such a manner that the flow of the content-forming phase joins the flows of the first and second continuous phases, to form microdroplets for forming contents; and then feeding a shell-forming phase to third and fourth continuous phases flowing in third and fourth microchannels, in such a manner that the flow of the shell-forming phase joins the junction of flows of the third and fourth continuous phases, to form coatings for forming shells to obtain microcapsules.

(11) In the emulsion-producing apparatus described in the above article (7) or (9), the means for feeding a plurality of the dispersion phases each include a substrate, a driven plate, an elastic member disposed between the substrate and the driven plate, and an actuator for driving the driven plate and thereby a plurality of the dispersion phases are fed at the same time.

(12) In the microcapsule-producing apparatus described in the above article (8) or (10), the means for feeding a plurality of shell-forming phases and content-forming phases each include a substrate, a driven plate, an elastic member disposed between the substrate and the driven plate, and an actuator for driving the driven plate, and thereby a plurality of the shell-forming phases and content-forming phases are fed at the same time.

(13) The emulsion-producing apparatus described in the above article (7) or (9) further includes films, disposed on portions of inner wall surfaces of the microchannel in which the continuous phase flows and the channel for feeding the dispersion phase, for readily forming the microdroplets, wherein the portions include the junction of the flows of the continuous phase and the dispersion phase and the vicinity of the junction.

(14) The microcapsule-producing apparatus described in the above article (8) or (10) further includes films, disposed on portions of inner wall surfaces of the microchannel in which the continuous phase flows and the channel for feeding the dispersion phase, for readily forming the microdroplets, wherein the portions include the junction of the flows of the continuous phase and the dispersion phase and the vicinity of the junction.

(15) An apparatus for producing an emulsion includes a substrate having parallel electrodes and a microchannel disposed on the substrate, wherein a dispersion phase disposed at the upstream side of the microchannel is attracted and then ejected by a moving electric field, applied to the parallel electrodes, to form the emulsion.

(16) In the emulsion-producing apparatus described in the above article (15), the arrangement of the parallel electrodes disposed at the side close to the continuous phase is changed, whereby the formed emulsion is guided in a predetermined direction.

(17) In the emulsion-producing apparatus described in the above article (15), the moving speed of the moving electric field applied to the parallel electrodes is varied, whereby the forming rate of the emulsion is varied.

(18) An apparatus for producing an emulsion includes an elastic member disposed between rigid members, placed at a lower section of a liquid chamber for a dispersion phase, having a plurality of microchannels therein; an actuator for applying a stress to the elastic member; and a continuous phase communicatively connected to a plurality of the microchannels.

(19) In the emulsion-producing apparatus described in the above article (18), a plurality of the microchannels each have a section, of which the diameter is decreased, having a tapered portion.

(20) In the emulsion-producing apparatus described in the above article (18), a plurality of the microchannels are provided, each of which have a lower section, of which the diameter is decreased, and having a first tapered portion and also each have having a protrusion having a second tapered portion for increasing the diameter of a further lower section.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be described in detail.

FIG. 1is a plan view showing an apparatus for producing microdroplets according to a first embodiment of the present invention, andFIG. 2is an illustration showing processes for producing such microdroplets.FIG. 2(a) is an illustration showing a microdroplet-producing process (No. 1),FIG. 2(b) is another illustration showing a microdroplet-producing process (No. 2),FIG. 2(b-1) is a fragmentary sectional view thereof, andFIG. 2(b-2) is the sectional view ofFIG. 2(b-1) taken along the line A-A.

In these figures, reference numeral1represents a main body of the microdroplet-producing apparatus, reference numeral2represents a microchannel in which a continuous phase flows and which is disposed in the main body1, reference numeral3represents a dispersion phase-feeding channel placed such that the dispersion phase-feeding channel3and the microchannel2cross, reference numeral4represents a dispersion phase-feeding port, reference numeral5represents the continuous phase (for example, oil), reference numeral6represents a dispersion phase (for example, water), reference numeral7represents a microdroplet, and reference numeral8represents a hydrophobic film.

In the above configuration, the dispersion phase6is fed to the continuous phase5flowing in the microchannel2in such a manner that flows of the dispersion phase6and the continuous phase5cross each other, as shown inFIG. 2. Part of the continuous phase5extends through each dispersion phase-feeding port4, thereby producing the microdroplets7having a diameter smaller than the width of the dispersion phase-feeding channel3.

For example, microdroplets having a diameter of about 25 μm can be obtained when the pressure of the dispersion phase (water)6is set to 2.45 kPa, the pressure of the continuous phase (oil containing 70% of oleic acid)5is set to 4.85 kPa, and the microchannel2and the dispersion phase-feeding channel3have a width of 100 μm and a height of 100 μm. When the pressure of the continuous phase is set to 5.03 kPa, microdroplets having a diameter of about 5 μm can be obtained.

As shown inFIGS. 2(b-1) and2(b-2), in order to readily form the microdroplets7(in order to readily repelling the microdroplets), the hydrophobic films8are preferably disposed on portions of the inner walls of the microchannel2, in which the continuous phase5flows, and the dispersion phase-feeding channel3, wherein the portions are disposed at the vicinity of the junction of the flows of the continuous phase (for example, oil)5and the dispersion phase (for example, water)6.

In the above embodiment, since the continuous phase5contains oil and the dispersion phase6contains water, the hydrophobic films8are preferably used. However, when the continuous phase contains water and the dispersion phase contains oil, hydrophilic films are preferably used.

FIG. 3is a plan view showing an apparatus for producing microcapsules according to a second embodiment, andFIG. 4is an illustration showing a process for producing such microcapsules.

In these figures, reference numeral11represents a main body of the microcapsule-producing apparatus, reference numeral12represents a microchannel in which a continuous phase flows and which is disposed in the main body11, reference numeral13represents a shell-forming phase-feeding channel placed such that the shell-forming phase-feeding channel13and the microchannel12cross, reference numeral14represents a content-forming phase-feeding channel placed such that the content-forming phase-feeding channel14and the microchannel12cross, reference numeral15represents a shell-forming phase-feeding port, reference numeral16represents a content-forming phase-feeding port, reference numeral17represents the continuous phase (for example, water), reference numeral18represents a shell-forming phase, reference numeral19represents a content-forming phase, and reference numeral20represents a microcapsule.

In the above configuration, the shell-forming phase18and the content-forming phase19are fed to the continuous phase17flowing in the microchannel12in such a manner that flows of the shell-forming phase18and the content-forming phase19join the flow of the continuous phase17, as shown inFIG. 4. The shell-forming phase18is fed from positions upstream to positions for feeding the content-forming phase19in such a manner that shell-forming phase18forms a thin layer.

FIG. 5is a plan view showing an apparatus for producing microdroplets according to a third embodiment, andFIG. 6is an illustration showing a process for producing such microdroplets.

In these figures, reference numeral21represents a main body of the microdroplet-producing apparatus, reference numeral22represents a first microchannel, reference numeral23represents a second microchannel, reference numeral24represents a first continuous phase, reference numeral25represents a second continuous phase, reference numeral26represents the junction of flows of the first continuous phase24and the second continuous phase25, reference numeral27represents a dispersion phase-feeding channel, reference numeral28represents a dispersion phase, and reference numeral29represents a microdroplet.

In the above configuration, the dispersion phase28is ejected toward the junction26of flows of the first continuous phase24and the second continuous phase25flowing in the microchannels22and23, respectively, in such a manner that the flow of the dispersion phase28joins the flows of the first continuous phase24and the second continuous phase25, as shown inFIG. 6. Thereby, the microdroplets29can be produced.

FIG. 7is a plan view showing an apparatus for producing microcapsules according to a fourth embodiment, andFIG. 8is an illustration showing a process for producing such microcapsules.

In these figures, reference numeral31represents a main body of the microcapsule-producing apparatus, reference numeral32represents a first microchannel in which a continuous phase flows and which is disposed in the main body31, reference numeral33represents a second microchannel in which another continuous phase flows and which is disposed in the main body31, reference numeral34represents a first continuous phase (for example, oil), reference numeral35represents a second continuous phase (for example, oil), reference numeral36represents the junction of flows of the first continuous phase34and the second continuous phase35, reference numeral37represents a content-forming phase-feeding channel, reference numeral38represents a content-forming phase (for example, water), reference numeral39represents a microdroplet (for example, water spheres), reference numeral40represents a third microchannel in which another continuous phase flows and which is disposed in the main body31, reference numeral41represents a fourth microchannel in which another continuous phase flows and which is disposed in the main body31, reference numeral42represents a third continuous phase (for example, water), reference numeral43represents a fourth continuous phase (for example, water), reference numeral44represents the junction of flows of the third continuous phase42and the fourth continuous phase43, reference numeral45represents a shell-forming phase, reference numeral46represents a shell-forming microdroplet, and reference numeral47represents a microcapsule.

In the above configuration, the content-forming phase38is fed to the continuous phases34and35flowing in the first and second microchannels32and33, respectively, in such a manner that the flow of the content-forming phase38joins the flows of the continuous phases34and35. Thereby, the microdroplets39for forming contents are formed.

Subsequently, the shell-forming phase45containing the first and second continuous phases34and35mixed together is fed to the continuous phases42and43flowing in the third and fourth microchannels40and41in such a manner that the flow of the shell-forming phase45joins the junction of the flows of the third and fourth continuous phases42and43. Thereby, a coating for forming a shell is formed on each microdroplet39for forming a content, thereby forming each microcapsule47.

In this embodiment, the microcapsule47contains the single microdroplet39. However, the microcapsule47may contain a plurality of the microdroplets39.

FIG. 9shows the particle size obtained by varying the height (which can be converted into the pressure) of the continuous phases and dispersion phases, when the first and second microchannels32and33and the content-forming phase-feeding channel37have a width of 100 μm and a height of 100 μm and the channel in which the microdroplets39are present have a width of 500 μm and a height of 100 μm. It is clear that the particle size can be controlled by varying the height (which can be converted into the pressure) of the continuous phases and dispersion phases.

FIG. 10is an illustration showing a mechanism for ejecting a dispersion phase, a shell-forming phase, or a content-forming phase placed in a microdroplet-producing apparatus according to a fifth embodiment of the present invention.FIG. 10(a) is an illustration showing a situation wherein the piezoelectric actuators are expanded and therefore such a phase is not ejected, andFIG. 10(b) is an illustration showing a situation wherein the piezoelectric actuators are contracted to eject the phase.

In these figures, reference numeral51represents a substrate, reference numeral52represents a driven plate, reference numeral53represents rubber, reference numeral54represents the piezoelectric actuators, each of which is disposed at the corresponding ends of the driven plate52, reference numerals55a-55drepresent a plurality of feeding ports, and reference numerals56a-56drepresent a plurality of channels arranged for a single dispersion phase. A back pressure is applied to the bottom portion of the dispersion phase.

In these figures, reference numeral51represents a substrate, reference numeral52represents a driven plate, reference numeral53represents rubber, reference numeral54represents the piezoelectric actuators each disposed at the corresponding ends of the driven plate52, reference numerals55a-55drepresent a plurality of feeding ports, and reference numerals56a-56drepresent a plurality of channels arranged for a single dispersion phase. A back pressure is applied to the bottom portion of the dispersion phase.

As shown inFIG. 10(a), a plurality of the channels56a-56dare arranged, and the dispersion phase can be ejected therefrom at the same time when the piezoelectric actuators54are contracted, as shown inFIG. 10(b).

Various actuators may be used instead of the above piezoelectric actuators.

FIG. 11is an illustration showing a mechanism for ejecting a dispersion phase, a shell-forming phase, or a content-forming phase placed in a microdroplet-producing apparatus according to a sixth embodiment of the present invention.FIG. 11(a) is an illustration showing such a situation that a bimorph actuator is not warped and therefore such a phase is not ejected, andFIG. 11(b) is an illustration showing such a situation that the bimorph actuator is warped, thereby ejecting the phase.

In these figures, reference numeral61represents the bimorph actuator, reference numeral62represents a fixed plate, reference numeral63represents rubber, reference numerals64a-64drepresent a plurality of feeding ports, and reference numerals65a-65drepresent a plurality of channels arranged for a single dispersion phase. A back pressure is applied to the bottom portion of the dispersion phase.

As shown inFIG. 11(a), a plurality of the channels65a-65dare arranged, and the dispersion phase can be ejected therefrom at the same time by the operation (upward warping) of the bimorph actuator61, as shown inFIG. 11(b).

FIG. 12is an illustration showing a mechanism for ejecting a dispersion phase, a shell-forming phase, or a content-forming phase placed in a microdroplet-producing apparatus according to a seventh embodiment of the present invention.FIG. 12(a) is an illustration showing a situation wherein an electrostrictive polymer is not energized and therefore such a phase is not ejected, andFIG. 12(b) is an illustration showing a situation wherein the electrostrictive polymer is energized (contracted), thereby ejecting the phase.

In these figures, reference numeral71represents a substrate, reference numeral72represents a driven plate, reference numeral73represents the electrostrictive polymer, reference numerals74a-74drepresent a plurality of feeding ports, and reference numerals75a-75drepresent a plurality of channels arranged for a single dispersion phase. A back pressure is applied to the bottom portion of the dispersion phase.

As shown inFIG. 12(a), a plurality of the channels75a-75dare arranged, and the dispersion phase can be ejected therefrom at the same time by the operation (contraction) of the electrostrictive polymer73, as shown inFIG. 12(b).

FIG. 13is an illustration showing a mechanism for opening or closing a dispersion phase-feeding port of a microdroplet-producing apparatus according to an eighth embodiment of the present invention.FIG. 13(a) is an illustration showing a situation wherein piezoelectric actuators are not energized (contracted) and therefore gates for a phase are opened, andFIG. 13(b) is an illustration showing a situation wherein piezoelectric actuators are energized (expanded) and thereby the gates for the phase are closed.

In these figures, reference numeral81represents a substrate, reference numeral82represents rubber, reference numeral83represents a driven plate, reference numeral84represents the piezoelectric actuators, reference numeral85represent a fixed plate, and reference numerals86a-86drepresent a plurality of the gates.

As shown in these figures, a plurality of the gates86a-86dare arranged, and all the gates for the phase can be closed by the operation of the two piezoelectric actuators84disposed at both sides.

Various actuators may be used instead of the above actuators.

FIG. 14is an illustration showing a mechanism for opening or closing a dispersion phase-feeding port of a microdroplet-producing apparatus according to a ninth embodiment of the present invention.FIG. 14(a) is an illustration showing a situation wherein a bimorph actuator is not energized (not warped) and therefore gates for a phase are opened, andFIG. 14(b) is an illustration showing such a situation that the bimorph actuator is energized (warped downward) and thereby the gates for the phase are closed.

In these figures, reference numeral91represents a substrate, reference numeral92represents rubber, reference numeral93represents the bimorph actuator, and reference numerals94a-94drepresent a plurality of the gates.

As shown in these figures, a plurality of the gates94a-94dare arranged, and all the gates can be closed at the same time by the operation of the bimorph actuator93.

FIG. 15is an illustration showing a mechanism for opening or closing a dispersion phase-feeding port of a microdroplet-producing apparatus according to a tenth embodiment of the present invention.FIG. 15(a) is an illustration showing a situation wherein an electrostrictive polymer is not energized and therefore the gates for a phase are opened, andFIG. 15(b) is an illustration showing such a situation that the electrostrictive polymer is energized (contracted) and thereby the gates for the phase are closed.

In these figures, reference numeral101represents a substrate, reference numeral102represents a driven plate, reference numeral103represents the electrostrictive polymer, and reference numerals104a-104drepresent a plurality of the gates.

As shown inFIG. 15(a), a plurality of the gates104a-104dare opened when the electrostrictive polymer103is not energized (expanded). As shown inFIG. 15(b), a plurality of the gates104a-104dare closed at the same time when the electrostrictive polymer103is energized (contracted).

FIG. 16is a plan view showing an emulsion-producing apparatus according to an eleventh embodiment of the present invention.FIG. 16(a) is a plan view showing the emulsion-producing apparatus to which a dispersion phase has not been introduced yet,FIG. 16(b) is a plan view showing the emulsion-producing apparatus to which liquid has been charged, andFIG. 16(c) is an illustration showing such a situation that a large droplet is set for the emulsion-producing apparatus and microdroplets (emulsion) are produced due to a moving electric field induced by static electricity.

In these figures, reference numeral111represents a substrate, reference numeral112represents electrodes disposed on the substrate111, reference numeral113represents a microchannel disposed above the substrate111having the electrodes112thereon, reference numeral114represents a dispersion phase, and reference numeral115represents an emulsion formed by causing the dispersion phase114to pass through the microchannel113.

In this embodiment, the electrodes112are arranged to be perpendicular to the microchannel113, and a moving electric field is applied to the electrodes112, thereby forming the emulsion115. The emulsion115is guided in the direction perpendicular to the electrodes (in the downward direction herein) depending on the moving electric field induced by the static electricity applied to the electrodes112.

The rate of forming the microdroplets can be changed by varying the moving speed of the moving electric field.

FIG. 17is a plan view showing an emulsion-producing apparatus according to a twelfth embodiment of the present invention.FIG. 17(a) is a plan view showing the emulsion-producing apparatus to which a dispersion phase has not been introduced yet, andFIG. 17(b) is an illustration showing such a situation that the dispersion phase is introduced to the emulsion-producing apparatus, thereby forming an emulsion.

In these figures, reference numeral121represents a substrate, reference numeral122represents electrodes disposed on the substrate121, reference numeral123represents a microchannel disposed above the substrate121having the electrodes122thereon, reference numeral124represents a dispersion phase, and reference numeral125represents an emulsion formed by causing the dispersion phase124to pass through the microchannel123.

In this embodiment, on the exit side of the microchannel123, the electrodes122are vertically arranged and thereby the formed emulsion125is guided in the horizontal direction depending on a static electricity applied to the electrodes122.

FIG. 18is an illustration showing an emulsion-forming apparatus according to a thirteenth embodiment of the present invention.FIG. 18(a) is a schematic view showing the total configuration of the monodispersed emulsion-forming apparatus, andFIG. 18(a-1) is the left side elevational view thereof,FIG. 18(a-2) is a schematic plan view thereof,FIG. 18(a-3) is the right side elevational view thereof.FIG. 18(b) is an illustration showing a first junction, andFIG. 18(C)is an illustration showing a second junction.

In these figures, reference numeral131represents a main body of the emulsion-forming apparatus, reference numeral132represents a microchannel in which a dispersion phase flows, reference numeral133represents a microchannel in which a first continuous phase flows, reference numeral134represents a microchannel in which a second continuous phase flows, reference numeral135represents the first junction at which flows of the dispersion phase and the first continuous phase are joined together, reference numeral136represents the second junction at which flows of the dispersion phase, the first continuous phase, and the second continuous phase are joined together, reference numeral137represents the first continuous phase, reference numeral138represents the dispersion phase, reference numeral139represents the second continuous phase, and reference numeral140represents a formed emulsion.

In this embodiment, the flows of the dispersion phase138and the first continuous phase137are joined together at the first junction135, thereby forming a two-phase flow containing the first continuous phase137and the dispersion phase138. At the second junction136, a flow of the second continuous phase139and the two-phase flow containing the first continuous phase137and the dispersion phase138are joined together, and thereby the emulsion140is formed from the dispersion phase138.

According to this embodiment, there is an advantage in that an emulsion having a size smaller than the width of channels can be readily formed.

FIG. 19is an illustration showing a microcapsule-forming apparatus according to a fourteenth embodiment of the present invention.FIG. 19(a) is a schematic view showing the total configuration of the microcapsule-forming apparatus, andFIG. 19(a-1) is the left side elevational view thereof,FIG. 19(a-2) is a schematic plan view thereof,FIG. 19(a-3) is the right side elevational view thereof.FIG. 19(b) is an illustration showing a first junction, andFIG. 19(C)is an illustration showing a second junction.

In these figures, reference numeral141represents a main body of the microcapsule-forming apparatus, reference numeral142represents a microchannel in which a dispersion phase (for example, water) flows, reference numeral143represents a microchannel in which a first continuous phase (for example, oil) flows, reference numeral144represents a microchannel in which a second continuous phase (for example, water) flows, reference numeral145represents the first junction at which flows of the dispersion phase and the first continuous phase are joined together, reference numeral146represents the second junction at which flows of the dispersion phase, the first continuous phase, and the second continuous phase are joined together, reference numeral147represents the first continuous phase, reference numeral148represents the dispersion phase, reference numeral149represents an emulsion (for example, water), reference numeral150represents the second continuous phase, and reference numeral151represents formed microcapsules. The microcapsules151can contain one or more emulsions149.

FIG. 20is an illustration showing a configuration of an apparatus of the present invention, wherein the apparatus can be used for forming a large amount of microdroplets (emulsion/microcapsules) using the elastic deformation of rubber.FIG. 21is an illustration showing the operation of a first forming apparatus therefor.

In these figures, reference numeral160represents a linear motor, reference numeral161represents a liquid chamber, reference numeral162represents a cover, reference numeral163represents a dispersion phase, reference numeral164represents an upper stainless plate, reference numeral165represents a rubber member, reference numeral166represents a lower stainless plate, reference numeral167represents microchannels, reference numeral168represents a continuous phase, and reference numeral169represents a formed emulsion (microdroplets). Another actuator including a piezoelectric actuator may be used instead of the linear motor160functioning as an actuator.

When the linear motor160is operated to apply a pressure to the liquid chamber161(seeFIG. 21(a)), to which a back pressure is applied, from above, the rubber member165disposed between the upper stainless plate164and the lower stainless plate166is pressed (seeFIG. 21(b)) and thereby part of the dispersion phase163is separated and then ejected from each microchannel167, thereby forming the microdroplets169. In this configuration, since a large number of the microchannels167extend through the upper stainless plate164, the rubber member165, and the lower stainless plate166, a large amount of the microdroplets169can be readily produced by the operation of the linear motor160at a time.

FIG. 22is an illustration showing the operation of a second apparatus, shown inFIG. 20, for forming a large amount of microdroplets.

In this embodiment, a plurality of the microchannels167each have a narrow section167B having a tapered portion167A formed by narrowing a lower channel portion.

When the linear motor160is operated to apply a pressure to the liquid chamber161(seeFIG. 22(a)), to which a back pressure is applied, from above, the rubber member165disposed between the upper stainless plate164and the lower stainless plate166is pressed from above (seeFIG. 22(b)) and thereby part of the dispersion phase163is separated and then ejected from each microchannel167, thereby forming the microdroplets169. In this configuration, since each microchannel167has the narrow lower portion having each tapered portion167A, the microdroplets169can be efficiently ejected in the downward direction.

FIG. 23is an illustration showing the operation of a third apparatus, shown inFIG. 20, for forming a large amount of microdroplets.

In this embodiment, a plurality of the microchannels167each have a narrow section167E that has a first tapered portion167C formed by narrowing a lower channel portion and a second tapered portion167D formed by expanding a further lower channel portion.

When the linear motor160is operated to apply a pressure to the liquid chamber161(seeFIG. 23(a)), to which a back pressure is applied, from above, the rubber member165disposed between the upper stainless plate164and the lower stainless plate166is pressed from above (seeFIG. 23(b)) and thereby part of the dispersion phase163is separated and then ejected from each microchannel167, thereby forming microdroplets169′. In this configuration, each microdroplet169′ is separated at each microchannel167having the first tapered portion167C, and the microdroplet169′ formed by separating part of the dispersion phase is guided along the second tapered portion167D in the downward direction and then efficiently ejected.

The present invention is not limited to the above embodiments, and various modifications may be performed within the scope of the present invention. The present invention covers such modifications.

As described above in detail, according to the present invention, an emulsion and microcapsules can be rapidly formed in a simple manner.

Furthermore, the formed emulsion can be guided in a predetermined direction and the rate of forming the emulsion can be varied.

Furthermore, the emulsion can be produced in a large scale.

INDUSTRIAL APPLICABILITY

According to a process and apparatus for producing an emulsion and microcapsules according to the present invention, an emulsion and microcapsules can be rapidly formed in a simple manner. Such a process and apparatus are fit for the field of drug production and biotechnology.