Apparatus for manufacturing dispersion and manufacturing method using the same

Abstract

To provide a manufacturing apparatus for a dispersion liquid with a novel configuration. [Solution] The manufacturing apparatus 100 disclosed herein comprises a container 10 for containing liquid LQ, a rod-shaped body 20 disposed inside the container 10, a porous portion 30 having a plurality of pores provided in at least one of the container 10 and the rod-shaped body 20, a fluid supply mechanism 40 for supplying fluid to the porous portion 30, and a rocking mechanism 50 for rocking at least one of the container 10 and the rod-shaped body 20 along the cylindrical axis.

Description

Technical Field

[0001] The present disclosure relates to a dispersion production apparatus and a production method using the same.

Background Art

[0002] In recent years, the utility of dispersions in which fine bubbles and liquid droplets (hereinafter may be collectively referred to as "fluid suspended matter") are dispersed in a liquid as a dispersion medium has attracted attention (see Patent Document 1 and Non-Patent Document 1). In this regard, for example, Patent Document 1 filed by the present inventors discloses a fine bubble generation apparatus that generates fine bubbles in a liquid. This apparatus includes a porous body having a plurality of fine pores for generating the fine bubbles in the liquid, a gas supply mechanism for supplying gas to the porous body, and a swinging mechanism for swinging the liquid, and is configured to discharge the gas supplied to the porous body into the liquid through the plurality of fine pores while the liquid is being swung by the swinging mechanism.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Further investigation by the present inventors revealed that in the apparatus of Patent Document 1, for example, when the viscosity of the liquid used as the dispersion medium is high, bubbles generated in the pores may adhere to the porous body and become difficult to release into the liquid, or bubbles generated in the liquid may become larger than the desired size.

[0006] This invention has been made in view of the above circumstances, and its purpose is to provide a novel dispersion manufacturing apparatus and a method for manufacturing a dispersion using the same, which can be suitably applied even when the viscosity of the liquid used as the dispersion medium is high. [Means for solving the problem]

[0007] The present invention provides an apparatus for producing a dispersion liquid in which fluid suspended matter is dispersed in a liquid used as a dispersion medium. The apparatus comprises a bottomed cylindrical container for containing the liquid; a rod-shaped body disposed inside the container and extending along the cylindrical axis of the container; a porous portion provided on the portion of at least one of the container and the rod-shaped body that is in contact with the liquid and having a plurality of pores for generating the suspended matter in the liquid; a fluid supply mechanism for supplying the fluid to the porous portion at a pressure equal to or greater than the suspended matter generation pressure that can generate the suspended matter from the pores; and a rocking mechanism for rocking at least one of the container and the rod-shaped body along the cylindrical axis while maintaining the porous portion in contact with the liquid.

[0008] In the above configuration, by oscillating at least one of the container and the rod-shaped body using the oscillating mechanism, fluid suspended particles (fine bubbles or droplets) can be generated in the liquid through multiple pores in the porous portion. This makes it possible to produce a suitable dispersion even when the viscosity of the liquid used as the dispersion medium is high.

[0009] Furthermore, the present invention provides a method for producing a dispersion using the above-described manufacturing apparatus. According to the above manufacturing method, even when the viscosity of the liquid used as the dispersion medium is high, it is possible to produce a dispersion by generating suitable fluid suspended matter (fine bubbles or droplets) in the liquid. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram showing the configuration of the manufacturing apparatus according to the first embodiment. [Figure 2] Figure 2 is a functional block diagram showing the configuration of the control unit. [Figure 3] Figure 3(A) is a graph showing the timing of gas supply in Example 6, and Figure 3(B) is a graph showing the timing of gas supply in Example 7. [Figure 4] Figure 4 is a graph showing the number density and average number diameter of bubbles in Examples 1 to 4. [Figure 5] Figure 5 is a graph showing the number density and average number diameter of bubbles in Examples 4 to 6. [Figure 6] Figure 6 is a graph showing the number density and average number diameter of bubbles in Examples 5, 6, and 8-13. [Figure 7] Figure 7 is a schematic diagram showing a modified example of a container, a rod-shaped body, and a porous section. [Figure 8] Figure 8 is a bar graph showing the average number and diameter of bubbles in Examples 14-25. [Figure 9] Figure 9 is a schematic diagram showing a modified gas supply mechanism. [Figure 10] Figures 10(A) and (B) are graphs showing the frequency distribution of bubble diameters for Examples 17 and 26. [Figure 11] Figure 11 is a diagram corresponding to Figure 1 according to the second embodiment. [Figure 12] Figures 12(A) to (F) are graphs showing the frequency distribution of droplet sizes for Examples 27 to 32. [Figure 13] Figure 13 is a graph comparing Examples 27-32 with Comparative Examples 1-6. [Modes for carrying out the invention]

[0011] The embodiments of the technology disclosed herein will be described below. Matters other than those specifically mentioned herein that are necessary for implementing the technology disclosed herein can be understood as design matters for those skilled in the art based on the prior art in the relevant field. The technology disclosed herein can be implemented based on the contents disclosed herein and the common technical knowledge in the relevant field. Furthermore, the notation "A~B" indicating a numerical range in this specification means "A or more and B or less", as well as "greater than A and less than B", "greater than A and less than or equal to B", and "A or more and less than B".

[0012] In this specification, "fluid suspended matter" refers to the dispersed phase of a fluid that does not dissolve in the liquid (continuous phase) that serves as the dispersion medium, but rather floats and disperses within the dispersion medium. This term includes fine bubbles (gas suspended matter) and fine droplets (liquid suspended matter). In this specification, "suspended matter" refers to matter with an average diameter of 150 μm or less (preferably 125 μm or less, more preferably 115 μm or less, even more preferably 110 μm or less, particularly preferably 100 μm or less, or 50 μm or less) from the viewpoint of dispersibility in the dispersion medium. In this specification, "average diameter" refers to the average diameter based on the number of suspended matter particles, calculated by randomly selecting 100 to 500 particles (e.g., 200 to 300 particles) from images acquired using a commercially available digital imaging device (e.g., a high-speed camera) and analyzing them using "ImageJ," a free image analysis software developed by the National Institutes of Health in the United States.

[0013] The mode diameter of the suspended matter is, for example, 150 μm or less, preferably 125 μm or less, more preferably 100 μm or less, even more preferably 75 μm or less, and particularly preferably 50 μm or less. Although not particularly limited, the mode diameter of the suspended matter is generally 5 μm or more, and may be 10 μm or more. As used in the present specification, the term "mode diameter" refers to the number-based most frequent diameter calculated by randomly selecting 100 to 500 (for example, 200 to 300) suspended matters from an image acquired using a commercially available digital imaging apparatus (for example, a high-speed camera), and performing analysis using image analysis software "ImageJ".

[0014] Further, the fine bubbles (gaseous suspended matter) can be so-called fine bubbles. Fine bubbles are defined as bubbles having a diameter of less than 100 μm according to the standard of the International Organization for Standardization (ISO) (ISO 20480-1:2017). The fine bubbles include microbubbles having a diameter of 1 μm or more and less than 100 μm, and ultrafine bubbles having a diameter of less than 1 μm. The dispersion liquid containing fine liquid droplets (liquid suspended matter) is a so-called emulsion.

[0015] <First Embodiment> Figure 1 is a schematic view of a manufacturing apparatus 100 according to the first embodiment. In the following description, reference sign VD in the drawings represents a vertical direction, an arrow of reference sign U represents an upward direction in the vertical direction, and an arrow of reference sign D represents a downward direction in the vertical direction. However, these directions are merely for convenience of description, and do not limit the installation form of the manufacturing apparatus 100 at all. Each drawing is a schematic view, and does not necessarily faithfully reflect an actual product.

[0016] The manufacturing apparatus 100 is an apparatus for manufacturing a dispersion liquid in which fluid suspended matter is dispersed in a liquid serving as a dispersion medium. The manufacturing apparatus 100 of the present embodiment is for manufacturing a dispersion liquid DL in which fine bubbles (gaseous suspended matter) are dispersed in a liquid LQ serving as a dispersion medium. The manufacturing apparatus 100 can also be understood as a bubble generating apparatus that generates fine bubbles in the liquid LQ serving as a dispersion medium.

[0017] As shown in Figure 1, the manufacturing apparatus 100 comprises a container 10, a rod-shaped body 20, a porous section 30, a gas supply mechanism 40, an oscillating mechanism 50, a bubble measuring unit 60, and a control device 70 (see Figure 2). The gas supply mechanism 40 is an example of a "fluid supply mechanism". Note that the bubble measuring unit 60 and the control device 70 are optional and can be omitted in other embodiments. As will be described in detail later, in the manufacturing apparatus 100, a porous section 30 is provided on the rod-shaped body 20. Gas G as a fluid is supplied to the porous section 30 from the gas supply mechanism 40. The oscillating mechanism 50 oscillates the rod-shaped body 20, thereby applying a shear force that changes over time (hereinafter also referred to as "accelerated shear force") to the rod-shaped body 20, and the gas G supplied to the porous section 30 is released into the liquid LQ as fine bubbles (suspended matter).

[0018] Container 10 is a casing for containing liquid LQ. Here, container 10 is a bottomed cylindrical shape (more specifically, a bottomed cylindrical shape) with one end (the lower end in Figure 1) closed and the other end (the upper end in Figure 1) open. Here, container 10 is positioned so that its cylindrical axis direction is aligned with the vertical direction VD. In this embodiment, the cylindrical axis direction is aligned with the vertical direction VD. Container 10 is made of a material that will not be corroded by the dispersion DL (especially the liquid LQ used as a dispersion medium), and from the viewpoint of durability, it is preferable that it be made of metal or glass, for example. Container 10 is fixed to an outer casing (not shown here) and is configured not to swing. Container 10 has a hollow structure. Container 10 has a bottom wall 10d, a side wall 10w, and a containment space HS. Here, the bottom wall 10d is flat, but in other embodiments, it does not have to be flat.

[0019] The containment space HS is provided in the hollow portion of the container 10 and is partitioned by the bottom wall 10d and the side wall 10w (inner wall surface). The containment space HS is larger than the outer shape of the rod-shaped body 20. The containment space HS contains the rod-shaped body 20 and the liquid LQ as a dispersion medium. The size of the containment space HS can be appropriately adjusted according to, for example, the size of the rod-shaped body 20 to be contained. The outer shape of the containment space HS is cylindrical, the same as the container 10. The length of the containment space HS in the axial direction is longer than the oscillation range of the porous portion 30 (stroke length, described later). The containment space HS (inner wall surface of the container 10) has a constant diameter D1 (not shown in Figure 1) in the axial direction. In the radial direction intersecting the axial direction, the diameter D1 of the containment space HS is larger than the diameter D2 (not shown in Figure 1) of the rod-shaped body 20, described later. <D1)。

[0020] The type of liquid LQ is not particularly limited. For example, liquid LQ may be an aqueous solvent containing water (typically water), an organic solvent containing one or more organic solvents, or a solution obtained by dissolving other compounds (solutes) in an aqueous solvent or organic solvent. It is preferable to adjust the liquid level of liquid LQ so that the porous portion 30 remains immersed while the rod-shaped body 20 is oscillating. In other words, it is preferable that the liquid level of liquid LQ is located above the upper end of the porous portion 30 while the rod-shaped body 20 is oscillating.

[0021] In this embodiment, the container 10 is provided with a communication port H1 that connects the containment space HS with the measurement channel 61 of the bubble measurement unit 60, which will be described later. The communication port H1 is located in the bottom wall 10d of the container 10 (vertically below the containment space HS). The liquid LQ (dispersion DL) containing bubbles flows out from the communication port H1 to the bubble measurement unit 60.

[0022] The rod-shaped body 20 is placed inside the container 10 (specifically, in the containment space HS) and is a member that extends along the cylindrical axis of the container 10. The external shape of the rod-shaped body 20 is cylindrical in this case. More specifically, it is a hollow cylindrical shape with a hollow portion in the radial center. The rod-shaped body 20 is made of a material that is not corroded by the dispersion liquid DL (especially the liquid used as the dispersion medium), and from the viewpoint of durability, it is preferable that it be made of, for example, ceramic or glass. The rod-shaped body 20 has a porous portion 30 in this case. As described in the first modified example below, the rod-shaped body 20 may be made of a porous portion 30 (porous member).

[0023] The rod-shaped body 20 has a constant diameter D2 (not shown in Figure 1) in the direction of the cylindrical axis. The axis of the rod-shaped body 20 coincides with the axis of the container 10. It is preferable that a predetermined clearance (gap) is secured around the rod-shaped body 20, more specifically between the outer surface of the rod-shaped body 20 and the inner wall surface of the container 10 (e.g., the side wall 10w). In the radial direction intersecting the cylindrical axis (vertical distance in the horizontal direction of Figure 1), the clearance around the rod-shaped body 20, in this case the clearance D3 (=(D1-D2) / 2) between the inner wall surface of the container 10 (more specifically the side wall 10w) and the outer surface of the rod-shaped body 20, is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.5 mm or more. This makes it easier for the rod-shaped body 20 to swing smoothly inside the container 10.

[0024] In some embodiments, the clearance D3 around the rod-shaped body 20 is preferably 10 mm or less, more preferably 5 mm or less, even more preferably 3 mm or less, and particularly preferably 2 mm or less. As described in the test examples later, by bringing the rod-shaped body 20 close to the inner wall surface of the container 10, a strong shear force is more easily applied to the surface of the porous portion 30. Therefore, it becomes easier to efficiently generate fine bubbles (suspended matter).

[0025] The rod-shaped body 20 has a support member 21. The support member 21 supports one end 20u (upper end in Figure 1) of the rod-shaped body 20 in the direction of the cylinder axis. The support member 21 has a through hole through which the gas supply passage 49 of the gas supply mechanism 40, described later, is inserted. The downstream end 49e of the gas supply passage 49 is located in the hollow portion of the rod-shaped body 20. The support member 21 is also electrically connected to the rocking mechanism 50 and is configured to rock along the direction of the cylinder axis (in this case, in the vertical direction VD) by the rocking mechanism 50. As a result, the rod-shaped body 20 supported by the support member 21 is rocked along the direction of the cylinder axis, and an accelerating shear force is applied to the rod-shaped body 20. In other words, the rod-shaped body 20 in this embodiment is a rocking body that is rocked by the rocking mechanism 50.

[0026] The porous portion 30 is provided on at least one of the container 10 and the rod-shaped body 20, in the portion that comes into contact with the liquid LQ. As shown in Figure 1, in this embodiment, the porous portion 30 is provided on the rod-shaped body 20. More specifically, it is provided on the vertically downward side of the rod-shaped body 20. The porous portion 30 is not provided on the container 10 in this embodiment. However, in other embodiments, the porous portion 30 may be provided on the side of the container 10. In that case, the porous portion 30 may not be provided on the rod-shaped body 20. The porous portion 30 is here cylindrical with one end (the lower end 30d in Figure 1) closed and the other end (the upper end 30u in Figure 1) open. More specifically, the porous portion 30 is a hollow cylindrical shape with a hollow portion in the radial center. In this embodiment, the above-mentioned clearance D3 is also secured around the porous portion 30, more specifically between the outer surface of the porous portion 30 and the inner wall surface of the container 10 (more specifically, the side wall 10w).

[0027] Gas G is supplied to the porous portion 30 by the gas supply mechanism 40. As shown in Figure 1, in this embodiment, the downstream end 49e of the gas supply channel 49 of the gas supply mechanism 40 (described later) is connected to the hollow portion (inner circumferential surface side) of the porous portion 30. As a result, gas G is supplied to the inner circumferential surface side of the porous portion 30.

[0028] Furthermore, as described above, in this embodiment, the rod-shaped body 20 supported by the support member 21 by the rocking mechanism 50 rocks along the cylindrical axis direction. Therefore, the porous portion 30 provided on the rod-shaped body 20 also rocks along the cylindrical axis direction. While the support member 21, the rod-shaped body 20, and the porous portion 30 rock along the cylindrical axis direction, at least a part (preferably the whole) of the porous portion 30 is maintained in contact with the liquid LQ. It is preferable that the porous portion 30 is maintained in a state where it is completely immersed in the liquid LQ while the support member 21, the rod-shaped body 20, and the porous portion 30 rock along the cylindrical axis direction.

[0029] The porous portion 30 has multiple pores that generate suspended matter (in this case, bubbles) in the liquid LQ. Preferably, the pores of the porous portion 30 have through holes that connect the inner circumferential surface and the outer circumferential surface. This makes it easier to efficiently generate a large amount of bubbles from the outer circumferential surface of the porous portion 30. The pore diameter of the porous portion 30 is preferably adjusted as appropriate depending on the properties of the desired dispersion DL, such as the type of liquid used, the desired size of bubbles (suspended matter), and the density of bubbles in the dispersion DL. Therefore, although not particularly limited, the average pore diameter of the porous portion 30 is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less, for example, 5 μm or less, 3 μm or less, and 2 μm or less, from the viewpoint of generating finer bubbles. Furthermore, the average pore diameter of the porous portion 30 is preferably 0.1 μm or larger, more preferably 0.3 μm or larger, and even more preferably 0.5 μm or larger, from the viewpoint of improving the permeability of the supplied gas G and increasing the density of bubbles.

[0030] The "average pore diameter" can be measured using a commercially available mercury porosimeter with a mercury intrusion method, for example, within a measurement pressure range of 1.5 to 20,000 psia (pore diameter range of 115 to 0.01 μm). An example of a mercury porosimeter is the "AutoPore IV 9500" manufactured by Micrometrics. Alternatively, the manufacturer's nominal value may be used as the average pore diameter.

[0031] The material of the porous portion 30 is not particularly limited as long as it has multiple pores. In some embodiments, the porous portion 30 is preferably made of ceramic from the viewpoint of durability, etc. Examples of ceramics that make up the porous portion 30 include alumina (Al2O3), zirconia (ZrO2), magnesia (MgO), silica (SiO2), titania (TiO2), zircon (ZrSiO4), and mullite (Al6O 13 Examples include oxide-based ceramics such as Si2; and non-oxide-based ceramics such as silicon nitride (Si3N4), boron nitride (BN), aluminum nitride (AlN), silicon carbide (SiC), and boron carbonitride (BCN). The ceramic may be used individually or as a composite material containing two or more of the above-mentioned ceramics. Among these, alumina, boehmite, silica, and titania are preferably used because they are stable in quality, inexpensive, and readily available. The chemical formulas in parentheses next to the names of each ceramic indicate typical compositions of the ceramic and do not mean that the composition of the ceramic is limited to those with such chemical formulas. Furthermore, the porous portion 30 may be made of metal, for example, or of resin (for example, a porous resin film).

[0032] The gas supply mechanism 40 is a mechanism that supplies fluid (in this case, gas G) to the porous section 30. As described above, in this embodiment, the porous section 30 is provided on the rod-shaped body 20, so the gas supply mechanism 40 is also a mechanism that supplies gas G to the rod-shaped body 20. The type of gas G is not particularly limited, as it is appropriately selected depending on the desired type of bubbles (suspended matter). Gas G can be, for example, air, oxygen gas, ozone, hydrogen gas, nitrogen gas, carbon dioxide gas, etc. In this case, gas G is air.

[0033] As shown in Figure 1, the gas supply mechanism 40 of this embodiment includes a supply source 41, a pressure regulating valve 42, a flow meter 43, an on-off valve 44, a pressure gauge 45, and a gas supply passage 49. The gas supply passage 49 is a gas supply passage for gas G from the supply source 41 to the downstream end 49e located in the hollow portion of the rod-shaped body 20. The gas supply passage 49 is, for example, a flexible tube. Along the gas supply passage 49, in order from the upstream side, are the supply source 41, the pressure regulating valve 42, the flow meter 43, the on-off valve 44, and the pressure gauge 45. The gas supply passage 49 may also be further provided with a transport device, such as a pump, as will be described in the second modified example described later.

[0034] The supply source 41 is connected to the upstream end of the gas supply channel 49. The supply source 41 is, for example, a gas cylinder. The pressure regulating valve 42 is a valve body that adjusts the supply pressure of the gas G supplied from the supply source 41. The pressure regulating valve 42 is, for example, a pressure reducing valve (relief valve) such as a regulator. The pressure regulating valve 42 is pre-adjusted to a pressure (bubble generation pressure P0) or higher that can generate bubbles (suspended matter) in the porous section 30. The bubble generation pressure P0 is an example of the "suspended matter generation pressure". The supply pressure of the gas G is preferably set to, for example, about 0.1 to 1 MPa. The pressure regulating valve 42 may be electrically connected to the control device 70 and controlled by the control device 70.

[0035] The flow meter 43 is a measuring instrument that measures the flow rate (amount of gas G supplied) of gas G in the gas supply passage 49. Here, the flow meter 43 is connected to the gas supply passage 49 between the pressure regulating valve 42 and the on-off valve 44. The flow meter 43 is electrically connected to the control device 70, and the amount of gas G supplied is transmitted to the control device 70. The pressure gauge 45 is a measuring instrument that measures the pressure (supply pressure of gas G) of gas G in the gas supply passage 49. Here, the pressure gauge 45 is installed between the on-off valve 44 and the porous section 30. The pressure gauge 45 is electrically connected to the control device 70, and the supply pressure of gas G is transmitted to the control device 70.

[0036] The on-off valve 44 is located in the middle of the gas supply passage 49. The on-off valve 44 is a component that opens and closes the gas supply passage 49. The on-off valve 44 is configured to switch between supplying and stopping the supply of gas G to the porous section 30. The on-off valve 44 is, for example, a solenoid valve. In this embodiment, the on-off valve 44 is electrically connected to the control device 70, and the control device 70 switches between an open state (supply of gas G) and a closed state (stopping the supply of gas G). As will be described in detail later, in this embodiment, a program is pre-stored in the control device 70 that opens and closes the on-off valve 44 in accordance with the operation of the oscillating mechanism 50 and switches between supplying and stopping the supply of gas G.

[0037] The rocking mechanism 50 is a mechanism that rocks at least one of the container 10 and the rod-shaped body 20 along the cylindrical axis while maintaining the porous portion 30 in contact with the liquid LQ. In this embodiment, the rocking mechanism 50 is a mechanism that rocks at least one of the container 10 and the rod-shaped body 20 in a direction toward the bottom wall 10d of the container 10 (first direction) and in a direction toward the bottom wall 10d of the container 10 and the rod-shaped body 20 and toward the bottom wall 10d However, in other embodiments, the rocking mechanism 50 may be attached to the container 10 and configured to rock the container 10 along the cylindrical axis. The rocking mechanism 50 is, for example, a known shaker. The rocking mechanism 50 is electrically connected to the control device 70, which switches between driving and stopping. In this specification, "rocking" means continuous reciprocating movement between two points in the cylindrical axis.

[0038] In some embodiments, the rocking mechanism 50 is preferably configured to rock the member of the container 10 and the rod-shaped body 20 that has the porous portion 30 along the cylindrical axis. For example, when the porous portion 30 is provided on the rod-shaped body 20 as in this embodiment, it is typically preferable to fix the container 10 and configure the rod-shaped body 20 to rock in the cylindrical axis direction. This improves the dissipation of bubbles generated in the porous portion 30, making it easier to efficiently generate fine bubbles (suspended matter) in the liquid LQ.

[0039] In some embodiments, the rocking mechanism 50 is preferably connected to the container 10 and the rod-shaped body 20, respectively, and configured to allow the container 10 and the rod-shaped body 20 to rock along the cylindrical axis. In one example, the rocking mechanism 50 is a mechanism that rocks the container 10 and the rod-shaped body 20 in a direction in which the bottom wall 10d of the container 10 and the rod-shaped body 20 move closer to each other (first direction) and in a direction in which they move away from each other (second direction). By rocking the container 10 and the rod-shaped body 20 in opposite directions, the shearing effect can be further enhanced, and the effects of the technology disclosed herein can be demonstrated at a higher level.

[0040] As shown in Figure 1, the rocking mechanism 50 is configured to rock the rod-shaped body 20 between a first position P1 located above the vertical direction VD and a second position P2 (shown by a dashed line in Figure 1) located below the vertical direction VD. Note that the first position P1 and the second position P2 in Figure 1 are merely examples, and the position is not particularly limited as long as the porous part 30 is inside the container 10 when the porous part 30 is rocked. The rocking mechanism 50 is configured to rock the rod-shaped body 20 downward D from the upper first position P1 to the lower second position P2, and upward U from the lower second position P2 to the upper first position P1. As the rod-shaped body 20 approaches the bottom wall 10d of the container 10, a strong accelerating shear force (accelerating shear force) may be applied to the rod-shaped body 20. Furthermore, when the rod-shaped body 20 moves downward D within the container 10, the liquid LQ moves upward U as the rod-shaped body 20 moves downward D. This can cause a strong accelerating shear force to be applied to the surface of the rod-shaped body 20 due to gravity. Therefore, it becomes easier to efficiently generate fine bubbles (suspended matter) in the liquid LQ.

[0041] The oscillation conditions of the rod-shaped body 20, such as the oscillation frequency and the stroke length in the axial direction of the cylinder (movement length, in this case the vertical distance between the first position P1 and the second position P2), are preferably adjusted as appropriate depending on the properties of the desired dispersion DL, such as the type of liquid used, the desired size of bubbles (suspended matter), and the density of bubbles in the dispersion DL. Furthermore, according to the inventors' studies, the optimal oscillation conditions may also vary depending on, for example, the clearance D3 and the pore diameter of the porous portion 30. Therefore, although not particularly limited, in some embodiments, the oscillation frequency is preferably 0.5 to 10 Hz, and more preferably 1 to 5 Hz.

[0042] In some embodiments, the stroke length of the rod-shaped body 20 is preferably shorter than the length of the container 10 in the axial direction, from the viewpoint of stable oscillation in the axial direction of the cylinder. When the length of the container 10 in the axial direction is taken as 100%, the stroke length of the rod-shaped body 20 is more preferably 90% or less, and even more preferably 80% or less. Furthermore, from the viewpoint of applying a strong accelerating shear force to the porous portion 30 and efficiently generating bubbles in the liquid LQ, the stroke length of the rod-shaped body 20 is preferably twice or more the length of the porous portion 30 in the axial direction, more preferably three times or more, and even more preferably five times or more. In one example, the stroke length is preferably 10 to 100 mm, and more preferably 20 to 50 mm.

[0043] The bubble measuring unit 60 is a device that measures the particle size and number of fine bubbles generated in the liquid LQ. As shown in Figure 1, the bubble measuring unit 60 is located vertically below the containment space HS. This makes it easier to guide the liquid LQ (dispersion DL) to the bubble measuring unit 60 using gravity. However, as will be described in the modified examples below, the bubble measuring unit 60 does not necessarily have to be located vertically below the containment space HS. The bubble measuring unit 60 in this embodiment has a measuring channel 61, a recovery channel 62, an opening valve 63, a recovery container 64, and a bubble detection unit 65. The liquid LQ (dispersion DL) containing the bubbles to be measured flows in from the communication port H1. The dispersion DL that flows in from the communication port H1 passes through the measuring channel 61 and the recovery channel 62 and is recovered in the recovery container 64.

[0044] The upstream end of the measuring channel 61 is connected to the communication port H1. The measuring channel 61 extends along the vertical direction VD. The measuring channel 61 is configured so that bubbles in the dispersion DL can be visually observed from the outside. The measuring channel 61 is made of, for example, glass or a resin such as polycarbonate. The measuring channel 61 is a thin plate with a thickness thinner than the containment space HS. The thickness of the measuring channel 61 may be, for example, 1 mm or less, preferably 500 μm or less. The measuring channel 61 has an outlet H2 connected to the recovery channel 62.

[0045] The recovery channel 62 has its upstream end connected to the outlet H2 of the measurement channel 61. The recovery channel 62 is, for example, a flexible tube. The release valve 63 is located in the middle of the recovery channel 62. The release valve 63 is a valve body that selectively opens the recovery channel 62 when measuring the particle size and number of bubbles contained in the dispersion DL. When the recovery channel 62 is opened by the release valve 63, flow occurs in the dispersion DL. This allows the dispersion DL to flow into the measurement channel 61, enabling suitable measurement of bubbles. The release valve 63 is, for example, a gate valve or a choke valve. The release valve 63 is electrically connected to the control device 70, and the control device 70 switches between a closed state and an open state. The recovery container 64 is located directly below the downstream end of the recovery channel 62. The dispersion DL is recovered into the recovery container 64.

[0046] The bubble detection unit 65 is positioned to capture images of the measurement channel 61. The bubble detection unit 65 is a device that detects bubbles in the dispersion liquid DL flowing through the measurement channel 61 using optical methods. The bubble detection unit 65 is a digital imaging device, such as a high-speed camera. In this case, the bubble detection unit 65 is electrically connected to the control device 70. Images (including video) acquired by the bubble detection unit 65 are transmitted to the control device 70, where the bubble size and number are calculated.

[0047] The control device 70 is configured to control a series of operations of the manufacturing apparatus 100. The control device 70 is, for example, a microcomputer. The hardware configuration of the control device 70 is not particularly limited, but for example, it includes a central processing unit (CPU) that executes instructions for the control program, a read-only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and a storage device such as memory that stores the program and various data.

[0048] Figure 2 is a functional block diagram of the control device 70. As shown in Figure 2, the control device 70 is electrically connected to the flow meter 43, pressure gauge 45, and on-off valve 44 of the gas supply mechanism 40, the oscillating mechanism 50, and the open valve 63 and bubble detection unit 65 of the bubble measuring unit 60, and is configured to control the operation of these components. The control device 70 is configured to generate bubbles in the liquid LQ by supplying gas G to the porous section 30 via the gas supply mechanism 40 and oscillating the rod-shaped body 20.

[0049] The control device 70 is also communicatively connected to the operation panel 80. The operation panel 80 has an input unit 81 in which the user inputs information regarding the settings of the manufacturing equipment 100, and a display unit 82 which displays the status of the manufacturing equipment 100, results obtained from measuring instruments, etc. The display unit 82 is, for example, a monitor, display, touch panel, etc.

[0050] The control device 70 of this embodiment includes a storage unit 71, a gas supply control unit 72, a oscillation control unit 73, and a calculation unit 74. However, in other embodiments, some of these (for example, the calculation unit 74) may be omitted, or other control units may be further included. Each part of the control device 70 is configured to communicate with each other. Each part of the control device 70 may be configured by software or by hardware. Each part of the control device 70 may be implemented by one or more processors or incorporated into a circuit. The storage unit 71 stores various settings necessary for the operation of the manufacturing apparatus 100.

[0051] The gas supply control unit 72 is a control unit that controls the gas supply mechanism 40 to adjust the supply of gas G to the porous section 30. In this embodiment, the gas supply control unit 72 controls the gas supply mechanism 40 in accordance with the operation of the oscillating mechanism 50 to adjust the supply of gas G to the porous section 30. The gas supply control unit 72 is configured to switch the supply and cessation of gas G to the porous section 30 by opening and closing the on-off valve 44. More specifically, the storage unit 71 has a program pre-stored in which the operation of the oscillating mechanism 50 corresponds to the opening and closing of the on-off valve 44. The gas supply control unit 72 is configured to switch the on-off valve 44 based on this program.

[0052] In some embodiments, the gas supply control unit 72 is preferably configured to open the on-off valve 44 only during a predetermined period of time while the rod-shaped body 20 is oscillating by the oscillating mechanism 50, thereby supplying gas G at or above the bubble generation pressure P0 (suspended matter generation pressure) to the porous section 30. That is, it is preferable to close the on-off valve 44 outside of the predetermined period so as not to supply gas G at or above the bubble generation pressure P0 to the porous section 30. In other words, when one cycle of oscillation is considered 100%, the percentage of time the on-off valve 44 is open (valve opening degree (%)) is preferably less than 100%. The valve opening degree is more preferably 50% or less, and even more preferably 10 to 30%. By switching the on-off valve 44 open or closed at least once during one cycle of oscillation, the flow rate of gas G can be varied. This improves bubble removal in the porous section 30, allowing for efficient bubble generation. Therefore, the density of bubbles in the liquid LQ can be increased. In addition, the size of the generated bubbles can be made smaller.

[0053] In some embodiments, the gas supply control unit 72 is preferably configured to open the on-off valve 44 when at least one of the container 10 and the rod-shaped body 20 moves in a direction (first direction) toward the bottom wall 10d of the container 10 and the rod-shaped body 20. More specifically, the gas supply control unit 72 is preferably configured to open the on-off valve 44 when the rod-shaped body 20 moves in a first direction (downward from the first position P1 toward the second position P2 in Figure 1) and / or when the container 10 moves in a second direction (upward from the second position P2 toward the first position P1 in Figure 1). In this embodiment, it is preferable that the on-off valve 44 is opened when the rod-shaped body 20 moves from the upper first position P1 toward the lower second position P2 by the rocking mechanism 50.

[0054] As a result, the gas supply mechanism 40 is controlled to supply gas G to the porous section 30 at a pressure equal to or greater than the bubble generation pressure P0 (suspended matter generation pressure) when at least one of the container 10 and the rod-shaped body 20 moves in the first direction. Here, the gas supply mechanism 40 is controlled to supply gas G to the porous section 30 at a pressure equal to or greater than the bubble generation pressure P0 (suspended matter generation pressure) when the rod-shaped body 20 moves downward D from the first position P1 to the second position P2. As described above, when the rod-shaped body 20 approaches the bottom wall 10d of the container 10, a strong accelerating shear force may be applied to the rod-shaped body 20. Therefore, by supplying gas G during the period when the rod-shaped body 20 moves in the first direction (the period when the greatest shear force is applied), bubble decomposition in the porous section 30 is improved, and bubbles can be generated efficiently. Thus, as described in the embodiments below, the density of bubbles in the liquid LQ can be increased. It is also possible to make the size of the generated bubbles smaller.

[0055] In some embodiments, the gas supply control unit 72 is preferably configured to close the on-off valve 44 when at least one of the container 10 and the rod-shaped body 20 moves away from the bottom wall 10d of the container 10 (second direction) by the rocking mechanism 50. More specifically, the gas supply control unit 72 is preferably configured to close the on-off valve 44 when the rod-shaped body 20 moves in the second direction (upward from the second position P2 to the first position P1 in Figure 1) and / or when the container 10 moves in the first direction (downward from the first position P1 to the second position P2 in Figure 1). In this embodiment, it is preferable that the on-off valve 44 is closed when the rod-shaped body 20 moves from the lower second position P2 to the upper first position P1 by the rocking mechanism 50.

[0056] As a result, the gas supply mechanism 40 controls the pressure of the gas G supplied to the porous section 30 to be less than the bubble generation pressure P0 (suspended matter generation pressure) for at least a portion of the time when at least one of the container 10 and the rod-shaped body 20 is moving in the second direction. Here, the gas supply mechanism 40 controls the pressure of the gas G supplied to the porous section 30 to be less than the bubble generation pressure P0 (suspended matter generation pressure) for at least a portion of the time when the rod-shaped body 20 is moving upward U from the second position P2 toward the first position P1. This improves bubble dissipation in the porous section 30, allowing for efficient bubble generation. Therefore, as described in the embodiments below, the density of bubbles in the liquid LQ can be increased. It also becomes possible to make the size of the generated bubbles smaller.

[0057] In some embodiments, the gas supply control unit 72 is preferably configured by the rocking mechanism 50 to switch (open and close) the on-off valve 44 at least once while at least one of the container 10 and the rod-shaped body 20 moves in a direction (first direction) toward the bottom wall 10d of the container 10 and the rod-shaped body 20. More specifically, the gas supply control unit 72 is preferably configured by the rocking mechanism 50 to switch (open and close) the on-off valve 44 at least once while the rod-shaped body 20 moves in a first direction (downward from the first position P1 toward the second position P2 in Figure 1) and / or while the container 10 moves in a second direction (upward from the second position P2 toward the first position P1 in Figure 1). In this embodiment, it is preferable that the rocking mechanism 50 is configured to switch (open and close) the on-off valve 44 at least once while the rod-shaped body 20 moves from the upper first position P1 toward the lower second position P2.

[0058] As a result, the gas supply mechanism 40 controls the pressure of the gas G supplied to the porous section 30 to be less than the bubble generation pressure P0 (suspended matter generation pressure) during a period when at least one of the container 10 and the rod-shaped body 20 is moving in the first direction. The gas supply mechanism 40 controls the pressure of the gas G supplied to the porous section 30 to be less than the bubble generation pressure P0 (suspended matter generation pressure) during a period when the rod-shaped body 20 is moving downward D from the first position P1 to the second position P2. As a result, as described in the embodiments below, the bubble dissipation in the porous section 30 is improved, making it possible to increase the bubble density while keeping the size of the generated bubbles approximately the same.

[0059] In some embodiments, the gas supply control unit 72 is preferably configured to open the on-off valve 44 when at least one of the container 10 and the rod-shaped body 20 begins to move in the direction (first direction) towards the bottom wall 10d of the container 10 and the rod-shaped body 20, via the oscillating mechanism 50. More specifically, the gas supply control unit 72 is preferably configured to open the on-off valve 44 when the rod-shaped body 20 begins to move in the first direction (downward from the first position P1 to the second position P2 in Figure 1), and / or when the container 10 begins to move in the second direction (upward from the second position P2 to the first position P1 in Figure 1). In this embodiment, it is preferable that the on-off valve 44 is opened when the rod-shaped body 20 begins to move downward from the upper first position P1 to the lower second position P2, via the oscillating mechanism 50.

[0060] As a result, the gas supply mechanism 40 is controlled to supply gas G to the porous section 30 at or above the bubble generation pressure P0 (suspended matter generation pressure) only during the period when at least one of the container 10 and the rod-shaped body 20 is moving in the first direction. Here, the gas supply mechanism 40 is controlled to supply gas G to the porous section 30 at or above the bubble generation pressure P0 (suspended matter generation pressure) only during the period when the rod-shaped body 20 is moving downward D from the first position P1 to the second position P2. As a result, as described in the embodiments below, it is possible to reduce the size of the generated bubbles while keeping the bubble density approximately the same.

[0061] The oscillation control unit 73 controls the drive of the oscillation mechanism 50 to oscillate the rod-shaped body 20 (at least one of the container 10 and the rod-shaped body 20) in the direction of the cylindrical axis. The oscillation conditions of the rod-shaped body 20 (at least one of the container 10 and the rod-shaped body 20), such as the oscillation frequency and the stroke length in the direction of the cylindrical axis, may be stored in advance in the storage unit 71. The oscillation conditions may be configured so that the user can select them from the conditions stored in advance in the storage unit 71 using the input unit 81, or they may be configured so that the user can set them directly from the input unit 81 within a predetermined range.

[0062] As described above, the oscillation conditions of the rod-shaped body 20 may vary depending on the properties of the desired dispersion DL, such as the size and density of bubbles. Therefore, in some embodiments, it is preferable that the memory unit 71 stores a first oscillation frequency and a second oscillation frequency that is higher than the first oscillation frequency. This allows the oscillation mechanism 50 to be switched between the first oscillation frequency and the second oscillation frequency. As described in the embodiments below, our inventors' studies have shown that increasing the oscillation frequency tends to relatively reduce the size of bubbles (suspended matter) and increase the density of bubbles. Therefore, the user can, for example, check the results obtained by the bubble detection unit 65 and select the second oscillation frequency if they want to make the bubble size smaller or increase the bubble density. The difference between the first oscillation frequency and the second oscillation frequency is preferably 1 Hz or more, and more preferably 2 Hz or more. In one example, the first oscillation frequency is 2 Hz and the second oscillation frequency is 4 Hz.

[0063] Furthermore, in some embodiments, it is preferable that the memory unit 71 stores a first stroke length and a second stroke length that is longer than the first stroke length. This allows the oscillating mechanism 50 to be configured to switch between the first stroke length and the second stroke length. According to the inventors' studies, increasing the stroke length tends to relatively reduce the size of the bubbles (floating particles) and increase the density of the bubbles. Therefore, the user can, for example, check the results obtained by the bubble detection unit 65 and select the second stroke length if they want to make the bubble size smaller or increase the density of the bubbles. The difference between the first stroke length and the second stroke length is preferably 10 mm or more, and more preferably 20 mm or more, although this may vary depending on the size of the container 10.

[0064] The calculation unit 74 is a control unit that calculates the size and number of bubbles from the image acquired by the bubble detection unit 65. The calculation unit 74 is composed of, for example, commercially available image analysis software. The calculation unit 74 may be configured to randomly select multiple bubbles from the acquired image and calculate the size of the bubbles (for example, the average diameter based on the number of bubbles) and the number of bubbles per unit volume of the dispersion DL (number density). The results calculated by the calculation unit 74 are displayed on the display unit 82. The results calculated by the calculation unit 74 may be linked to, for example, the oscillation conditions of the oscillation mechanism 50 and stored in the storage unit 71.

[0065] In the manufacturing apparatus 100 disclosed herein, for example, first, with the opening valve 63 closed, a rod-shaped body 20 having a porous portion 30 and liquid LQ are placed in the storage space HS of the container 10. The user inputs or selects the oscillation conditions for the oscillation mechanism 50 from the input unit 81. Next, when the on-off valve 44 of the gas supply mechanism 40 is opened, gas G adjusted to a predetermined supply pressure is supplied to the inner circumference of the porous portion 30. In this state, the rod-shaped body 20 is oscillated by the oscillation mechanism 50 under predetermined oscillation conditions, thereby generating an accelerating shear force on the rod-shaped body 20. As a result, the gas G supplied to the porous portion 30 is released into the liquid LQ as fine bubbles (suspended matter) from multiple pores in the porous portion 30. This allows for the production of a dispersion DL. This method allows for the efficient generation of fine bubbles in the liquid LQ.

[0066] In this embodiment, the release valve 63 is further opened to allow the obtained dispersion DL to flow through the measurement channel 61, and the bubble detection unit 65 acquires an image of the bubbles contained in the dispersion DL. The obtained image is sent to the control device 70, and the calculation unit 74 calculates the particle size and number of bubbles. The results calculated by the calculation unit 74 are displayed on the display unit 82. Thus, the user can understand the properties of the obtained dispersion DL, specifically the size and density of the bubbles contained in the dispersion DL.

[0067] As described above, in the manufacturing apparatus 100, a porous section 30 is provided in at least one of the container 10 and the rod-shaped body 20. The gas supply mechanism 40 supplies gas G as a fluid to the porous section 30 at a pressure equal to or greater than the bubble generation pressure P0 (suspended matter generation pressure), and the oscillating mechanism 50 oscillates at least one of the container 10 and the rod-shaped body 20. As a result, an accelerating shear force is applied to the porous section 30, and the gas G supplied to the porous section 30 is released into the liquid LQ as fine bubbles (suspended matter) through multiple pores. With this configuration, a dispersion liquid DL in which bubbles are dispersed in the liquid LQ can be suitably manufactured.

[0068] Next, a test example relating to the first embodiment of the technology disclosed herein will be described. Note that the test example described below is not intended to limit the technology disclosed herein.

[0069] <Test 1> In Test 1, the dispersion DL was manufactured using the manufacturing apparatus 100 according to the first embodiment. The configuration of the apparatus used in Test 1 is shown in Figure 1. Therefore, the reference numbers assigned to each name of the apparatus below are the numbers shown in Figure 1.

[0070] -Examples 1-16- First, two types of bottomed cylindrical containers 10 with a cylindrical length of 70 mm in the axial direction (with different inner diameters D1) and a hollow cylindrical rod-shaped body 20 with a diameter D2 of 12 mm and a cylindrical length of 20 mm in the axial direction were prepared. The rod-shaped body 20 is provided with a porous section 30 with a cylindrical length of 10 mm. The porous section 30 has the average pore size shown in the corresponding column of Table 1 and is composed of a hollow cylindrical porous material mainly made of alumina. Next, a support member 21 was attached to the upper end of the rod-shaped body 20 and it was placed in the storage space HS of the container 10. A clearance D3 shown in the corresponding column of Table 1 is secured around the rod-shaped body 20 (porous section 30), in this case between it and the inner wall surface of the container 10. The clearance D3 was adjusted by changing the inner diameter D1 of the container 10. Next, liquid LQ (water in this case) was poured into the storage space HS of the container 10, so that the rod-shaped body 20 and the porous section 30 were immersed in the liquid LQ. Next, the pressure regulating valve 42 was adjusted to a pressure (bubble generation pressure P0) that is equal to or greater than the pressure at which bubbles can be generated in the porous section 30.

[0071] Next, the oscillation mechanism 50 was controlled to oscillate the rod-shaped body 20 (and the porous section 30) in the vertical direction VD at the oscillation frequency shown in the corresponding column of Table 1. The vertical stroke length of the rod-shaped body 20 was kept constant at 40 mm. Then, the gas supply mechanism 40 was controlled to supply gas G to the inner surface side of the porous section 30 at a predetermined timing. In this case, air was used as the gas G. The timing of supplying gas G was adjusted so that it corresponded to the valve opening shown in the corresponding column of Table 1 during the period in which the rod-shaped body 20 was oscillated by the oscillation mechanism 50.

[0072] In the embodiment where the "valve opening (%)" in Table 1 is 100%, the on-off valve 44 is kept open at all times, and gas G is continuously supplied to the porous section 30. In the embodiment where the "valve opening (%)" is less than 100%, the on-off valve 44 is switched according to the operation of the oscillating mechanism 50, and the on-off valve 44 is kept closed for a certain period of time. Specifically, in the embodiment where the valve opening is 50%, the on-off valve 44 is kept open only for 50% of one cycle of oscillating (half a cycle, in this case the period during which the rod-shaped body 20 moves downward D), and gas G is supplied to the porous section 30. In the embodiment where the valve opening is 20%, the on-off valve 44 is kept open only for 20% of one cycle of oscillating (in this case 40% of the period during which the rod-shaped body 20 moves downward D), and gas G is supplied to the porous section 30.

[0073] Furthermore, for the examples where "Periodic shift" is indicated in the "Valve Opening (%)" column in Table 1, the timing of opening the on-off valve 44 was changed. Figure 3(A) is a graph showing the timing of gas supply (the period during which the on-off valve 44 is open) in Example 6. As shown in Figure 3(A), in Example 6, the on-off valve 44 was opened and gas G was supplied during the final period of movement downward D. Figure 3(B) is a graph showing the timing of gas supply (the period during which the on-off valve 44 is open) in Example 7. As shown in Figure 3(B), in Example 7, the on-off valve 44 was opened immediately at the timing when movement downward D began, and gas G was supplied so that the pressure was equal to or greater than the bubble generation pressure P0 only during the period when the rod-shaped body 20 was moving downward D.

[0074] As described above, bubbles were generated in the liquid LQ from the pores of the porous section 30 to obtain a dispersion DL containing bubbles. Then, the release valve 63 was opened to allow the dispersion DL to flow through the measurement channel 61, and an image of the bubbles contained in the dispersion DL was acquired by the bubble detection unit 65 (high-speed camera in this case). From the acquired image, 300 bubbles were randomly selected, and the number average diameter (μm) and number density (bubbles / ml) of the bubbles were calculated using the image analysis software "ImageJ". The results are shown in the corresponding column of Table 1. Note that the number average diameter (μm) is the arithmetic mean of the bubble diameters based on the number of bubbles analyzed.

[0075] [Table 1]

[0076] Figure 4 is a graph showing the number density and average number diameter of bubbles in Examples 1 to 4. As shown in Figure 4 and Table 1, in Examples 2 and 4, where the oscillation frequency of the rod-shaped body 20 (porous portion 30) was 4 Hz, the bubbles were finer compared to Examples 1 and 3, where the oscillation frequency was 2 Hz. The bubble density was also higher. From this, it was found that the average diameter and density of bubbles can be adjusted by changing the oscillation frequency. More specifically, it was found that increasing the oscillation frequency can make the bubbles finer and increase their density.

[0077] Furthermore, in Examples 3 and 4, where the valve opening was 50%, the bubble density was significantly higher compared to Examples 1 and 2, where the valve opening was 100%. In addition, the bubbles were also finer. From this, it was found that the average diameter and density of bubbles can be adjusted by changing the valve opening (the supply time of gas G). Specifically, it was found that by setting the valve opening to less than 100% (50% or less in this case), the bubbles can be made finer and their density can be increased.

[0078] Figure 5 is a graph showing the number density and average number diameter of bubbles in Examples 4 to 6. As shown in Figure 5 and Table 1, in Example 5, where the clearance D3 was 1.5 mm, the bubbles were finer compared to Example 4, where the clearance D3 was 4.5 mm. From this, it was found that the average diameter of bubbles can be adjusted by changing the clearance D3. More specifically, it was found that the bubbles can be made finer by narrowing the clearance D3. The bubble density was approximately the same in both examples.

[0079] Furthermore, in Example 6, where the valve opening was 20%, the bubble density was higher than in Example 5, where the valve opening was 50%. This indicates that the bubble density can be further increased by adjusting the valve opening (gas G supply time). The average diameter of the bubbles was approximately the same in both cases.

[0080] Furthermore, comparing Examples 6 and 7 in Table 1, as shown in Figure 3(B), in Example 7, where gas G was supplied so that bubbles were generated only when the rod-shaped body 20 was oscillating downward D, the bubbles were finer compared to Example 6. The bubble density was also higher. From this, it was found that the average diameter and density of bubbles can be adjusted not only by changing the valve opening but also by changing the timing of gas supply. Specifically, it was found that the bubbles can be made finer and their density increased by adjusting the timing of gas supply.

[0081] Figure 6 is a graph showing the number density and average number diameter of bubbles in Examples 5, 6, and 8-13. As shown in Figure 6 and Table 1, in Examples 8-13, where the average pore diameter of the porous section 30 was 0.5 μm, the bubbles were finer compared to Examples 5 and 6, where the average pore diameter of the porous section 30 was 1.3 μm. The bubble density was also higher. This indicates that the average diameter and density of bubbles can be adjusted by changing the average pore diameter of the porous section 30. More specifically, it was found that reducing the average pore diameter of the porous section 30 could make the bubbles finer and increase their density. The effects of oscillation frequency and valve opening were similar when the average pore diameter of the porous section 30 was 1.3 μm and when it was 0.5 μm.

[0082] The manufacturing apparatus 100 (a manufacturing apparatus for a dispersion liquid DL containing bubbles) of the first embodiment disclosed herein has been described above. However, the manufacturing apparatus disclosed herein is not limited thereto and may include other modifications.

[0083] For example, in the manufacturing apparatus 100, the gas supply mechanism 40 is equipped with an on-off valve 44, and the gas supply control unit 72 is configured to open and close the on-off valve 44 in accordance with the operation of the oscillating mechanism 50, switching between supplying and stopping the supply of gas G. However, it is not limited to this. The gas supply mechanism 40 may be configured to adjust the supply amount and supply pressure of gas G in accordance with the operation of the oscillating mechanism 50. In one example, the gas supply control unit 72 may be configured to control a pressure regulating valve 42 in accordance with the operation of the oscillating mechanism 50, switching the supply pressure of gas G between a state where it is above the bubble generation pressure P0 and a state where it is below the bubble generation pressure P0.

[0084] Furthermore, in the manufacturing apparatus 100, for example, the cylindrical axis direction of the container 10 coincides with the vertical direction VD, and the rocking mechanism 50 is configured to rock the rod-shaped body 20 along the vertical direction VD. However, it is not limited to this. The container 10 may be positioned in a direction intersecting the vertical direction VD, for example, diagonally, or along the horizontal direction. In this case, the rod-shaped body 20 may be rocked by the rocking mechanism 50 in a direction intersecting the vertical direction VD.

[0085] Furthermore, in the manufacturing apparatus 100, for example, a communication port H1 is provided in the bottom wall 10d of the container 10, and the dispersion liquid DL is configured to flow from the vertically downward direction of the containment space HS to the bubble measuring unit 60. However, it is not limited to this. For example, when the capacity of the container 10 is large, the bubble measuring unit 60 may be configured to collect the dispersion liquid DL from the containment space HS from the open end of the container 10 (the upper end in Figure 1). In that case, the bubble measuring unit 60 may have, for example, a flow path whose upstream end is located within the containment space HS, and a liquid delivery pump provided in the flow path. In addition, the manufacturing apparatus 100 may further include a recovery mechanism 270 as shown in the second embodiment, instead of the bubble measuring unit 60, or in addition to the bubble measuring unit 60.

[0086] <First variation> Figure 7 is a schematic diagram showing a modified container 110, rod-shaped body 120, and porous portion 130. As shown in Figure 7, in this modified example, the rod-shaped body 120 is made of a porous portion 130 (porous member). The porous portion 130 is rod-shaped. As a result, the length of the porous portion 130 in the cylindrical axis direction is longer than that of the porous portion 30 in the above-described embodiment.

[0087] Container 110 is a casing that houses the liquid LQ and the rod-shaped body 120 (rod-shaped porous portion 130). Here, container 110 is a bottomed cylindrical shape (more specifically, a bottomed rectangular cylindrical shape) with one end (lower end in Figure 7) closed and the other end (upper end in Figure 7) open. Container 110 is positioned so that its cylindrical axis is aligned with the vertical direction VD. Container 110 has a larger storage space HS than container 10 described above. The length of the storage space HS in the cylindrical axis direction is longer than the stroke length of the rod-shaped body 120 (porous portion 130). In addition to the rod-shaped body 120 and the liquid LQ, a partition member 112 is placed in the storage space HS of container 110.

[0088] The partition member 112 is positioned around the rod-shaped body 120 (porous portion 130). The partition member 112 is a component that partitions the space between the outer surface of the rod-shaped body 120 and the inner wall surface 110w (in this case, the side surface) of the container 110, thereby adjusting the clearance D4 around the rod-shaped body 120. The partition member 112 is installed at the bottom of the container 110. The partition member 112 is hollow and cylindrical. The partition member 112 is positioned so that its cylindrical axis is aligned with the vertical direction VD. The inside of the partition member 112 is filled with liquid LQ. The rod-shaped body 120 is oscillated along the cylindrical axis of the partition member 112 by the oscillating mechanism 50 described above. The rod-shaped body 120 is oscillated between a first position P1 on the upper side and a second position P2 on the lower side. Note that the first position P1 and the second position P2 in Figure 7 are merely examples, and the position is not particularly limited as long as the porous part 130 is inside the container 10 when the porous part 130 is oscillated. Preferably, the length of the rod-shaped body 120 in the axial direction is longer than the stroke length. However, the rod-shaped body 120 may be oscillated inside the container 110 such that a part of it protrudes from the upper end of the partition member 112.

[0089] In this modified example, compared to the first embodiment shown in Figure 1, the length of the porous portion 130 in the axial direction can be increased, and the stroke length can be increased. This allows for the efficient generation of fine bubbles, enabling the production of a large quantity of dispersion liquid DL. Therefore, it is suitable for the mass production of dispersion liquid DL. Furthermore, the manufacturing apparatus according to this modified example is particularly suitable for producing dispersion liquid DL using a liquid with a higher viscosity than water as the dispersion medium, for example, a liquid with a viscosity of 10 mPa·s or more, 50 mPa·s or more, or 100 mPa·s or more. From the viewpoint of exhibiting the effects of the technology disclosed herein at a higher level, the viscosity of the dispersion medium is preferably 500 mPa·s or less, more preferably 300 mPa·s or less, and even more preferably 200 mPa·s or less. In this specification, "viscosity" refers to the value measured using a parallel-disc type rotational viscometer (Type B viscometer) at a rotor rotation speed of 20 rpm at a liquid temperature of 20°C.

[0090] Next, we will describe test examples related to this modified example. Note that the following test examples are not intended to limit the technology disclosed herein.

[0091] <Test 2> In Test 2, dispersion DL was produced using a manufacturing apparatus equipped with a container 110 and a rod-shaped body 120 (porous part 130) according to the first modification. The configuration of the apparatus used in Test 2 is shown in Figures 1 and 7. Therefore, the reference numbers assigned to each name of the apparatus below are the numbers shown in Figures 1 and 7.

[0092] -Examples 14-25- First, a bottomed rectangular container 110 measuring 200 mm in length, 90 mm in width, and 30 mm in thickness, a hollow cylindrical partition member 112 with an inner diameter of 14 mm and a length in the axial direction of the cylinder of 70 mm, and a hollow cylindrical rod-shaped body 120 with a diameter of 12 mm and a length in the axial direction of the cylinder of 20 mm were prepared. The rod-shaped body 120 is composed of a porous section 130. The porous section 130 has the average pore size shown in the corresponding column of Table 2 and is composed of a hollow cylindrical porous body (rod-shaped porous section) mainly composed of alumina.

[0093] Next, a support member 21 was attached to the upper end of the rod-shaped body 120 (porous portion 130), and the rod-shaped body 120 was placed in the storage space HS of the container 110. In the embodiments where "-" is indicated in the "Clearance D4" column of Table 2, the partition member 112 was not installed, and the clearance around the rod-shaped body 120 (between the container 110 and the rod-shaped body 120) was increased. In the embodiments where "1 mm" is indicated in the "Clearance D4" column of Table 2, the partition member 112 was installed around the rod-shaped body 120. Next, liquid LQ was poured into the storage space HS of the container 110, and the rod-shaped body 120 (porous portion 130) was immersed in liquid LQ. Here, a xanthan gum solution was used as liquid LQ, obtained by dissolving xanthan gum in water at the concentration shown in the corresponding column of Table 2. The viscosity of liquid LQ is also shown in the corresponding column of Table 2.

[0094] Next, the gas flow meter 43 was adjusted to 2.0 mL / min, and gas G (nitrogen in this case) was supplied to the porous section 130 at a supply pressure of 0.2 to 0.45 MPa, so that gas G would be discharged from the porous section 130. Then, the oscillating mechanism 50 was used to oscillate the rod-shaped body 120 (porous section 130) in the vertical direction VD at an oscillating frequency of 3 Hz. The vertical stroke length of the rod-shaped body 120 was kept constant at 50 mm. The valve opening (%) during the oscillating period was kept constant at 20%.

[0095] As described above, a dispersion DL containing bubbles in a xanthan gum solution was obtained. Then, after taking a sample of the dispersion DL from the upper side of the containment space HS (the open upper end side of container 110), the average number diameter (μm) of bubbles contained in the dispersion DL was calculated using the same method as in Test 1 described above. The results are shown in the corresponding column of Table 2.

[0096] [Table 2]

[0097] Figure 8 is a bar graph showing the average number and diameter of bubbles in Examples 14-25. As shown in Figure 8 and Table 2, the average diameter of bubbles in the dispersion DL was affected by the viscosity (xanthan gum concentration) of the liquid LQ used as the dispersion medium. Specifically, the higher the viscosity of the liquid LQ, the more difficult it was to miniaturize the bubbles. However, it was found that even in highly viscous solutions of liquid LQ, for example, with a viscosity of around 50-200 mPa·s, bubbles could be suitably miniaturized by reducing the average pore diameter of the porous portion 130 or by installing partition members 112 around the rod-shaped body 120 to narrow the clearance around the rod-shaped body 120 (porous portion 130).

[0098] <Second variation> Figure 9 is a schematic diagram showing a modified gas supply mechanism 140. As shown in Figure 9, the gas supply mechanism 140 of this modified example further includes a pump 46. The pump 46 is a pump that pulsates the gas G in the gas supply passage 49 in a range of bubble generation pressure P0 or higher, thereby causing small fluctuations in the supply pressure of the gas G. In this example, the pump 46 is a pressure reducing pump. However, the pump 46 may be a pulsating pump or the like. The pump 46 may have a pressing roller (pressing part) that can be switched between a pressing state that presses the gas supply passage 49 and an open state that does not press the gas supply passage 49. In this example, the pump 46 is connected to a motor. The motor is electrically connected to a control device 70, and its driving and stopping are controlled by the control device 70. As a result, the supply pressure of the gas G in the gas supply passage 49 fluctuates.

[0099] Next, we will describe test examples related to this modified example. Note that the following test examples are not intended to limit the technology disclosed herein.

[0100] <Test 3> In Test 3, dispersion DL was produced using a manufacturing apparatus equipped with a gas supply mechanism 140 according to the second modified example. The configuration of the gas supply mechanism 140 used in Test 3 is shown in Figure 9. Therefore, the reference numbers assigned to each name below are the numbers shown in Figure 9.

[0101] -Example 26- In Example 26, the dispersion DL was obtained in the same manner as in Example 17, except that the pump 46 was driven at 50 Hz with a gas G supply pressure of 0.35 MPa as the reference, and the supply pressure was increased and decreased in small increments (causing gas G to pulsate). Then, the average number diameter (μm) of bubbles contained in the dispersion DL was calculated in the same manner as in Test 2 described above. The results are shown in the corresponding column of Table 3.

[0102] [Table 3]

[0103] Figure 10(A) is a graph showing the frequency distribution of bubble diameters in Example 17, and Figure 10(B) is a graph showing the frequency distribution of bubble diameters in Example 26. As shown in Figures 10(A), 10(B), and Table 3, in Example 26, where gas G was pulsated, both the D32 particle size (the diameter at which the cumulative frequency from the smallest diameter side is 32%) and the average diameter were smaller compared to Example 17, indicating that the bubbles in the dispersion DL were finer. The CV value (Coefficient of Variation, an index of variability relative to the mean) was approximately the same. From this, it was found that bubbles can be made finer by pulsating gas G.

[0104] <Second Embodiment> Figure 11 is a schematic diagram of the manufacturing apparatus 200 according to the second embodiment. The manufacturing apparatus 200 is an emulsifier for producing an emulsion EM, which is a dispersion liquid in which fine droplets (liquid suspended matter) of a second liquid are dispersed in a first liquid LQ as a dispersion medium. More specifically, the manufacturing apparatus 200 here is for producing an oil-in-water (O / W) emulsion in which an oil phase is dispersed as a dispersion phase in an aqueous phase as a continuous phase. The manufacturing apparatus 200 can also be understood as a droplet generator that generates fine droplets of the second liquid in the first liquid LQ as a dispersion medium. However, in other embodiments, the manufacturing apparatus 200 may be for producing a water-in-oil (W / O) emulsion in which an aqueous phase is dispersed as a dispersion phase in an oil phase as a continuous phase. Note that in the following, explanations of matters common to the first embodiment may be omitted or simplified.

[0105] As shown in Figure 11, the manufacturing apparatus 200 includes a container 210, a porous body (rod-shaped porous section) 230, a dispersed phase supply mechanism 240, an oscillating mechanism 250, a dispersion medium supply mechanism 260, a recovery mechanism 270, and a control device (not shown). The dispersed phase supply mechanism 240 is an example of a "fluid supply mechanism". Note that the recovery mechanism 270 and the control device are optional and can be omitted in other embodiments. As will be described in detail later, in the manufacturing apparatus 200, a first liquid LQ (continuous phase) is supplied to the container 210 from the dispersion medium supply mechanism 260. A second liquid (oil OL) is supplied to the porous body 230 as a fluid (dispersed phase) from the dispersed phase supply mechanism 240. The oscillating mechanism 250 oscillates the porous body 230, applying an accelerating shear force to the porous body 230, and the oil OL supplied to the porous body 230 is released into the first liquid LQ as fine droplets (suspended matter).

[0106] The container 210 is a bottomed cylindrical casing that contains a first liquid LQ as a dispersion medium. Here, the container 210 is positioned so that its cylindrical axis is aligned with the vertical direction VD. In this embodiment, the cylindrical axis is aligned with the vertical direction VD. The lower end of the container 210 is fixed to a support base 211. A porous body 230 is contained in the containment space of the container 210. The side walls of the container 210 are formed to be relatively thicker in the vicinity of the porous body 230. The first liquid LQ is supplied to the containment space of the container 210 by a dispersion medium supply mechanism 260. Specifically, an inlet H3 is provided in the bottom wall of the container 210. The inlet H3 is connected to the dispersion medium supply mechanism 260.

[0107] The dispersion medium supply mechanism 260 is a mechanism for continuously supplying a first liquid LQ to the containment space of the container 210. The first liquid LQ constitutes the continuous phase (aqueous phase) of the dispersion liquid EM, and in this case is an aqueous solution (e.g., water). The type of the first liquid LQ is not particularly limited. The dispersion medium supply mechanism 260 of this embodiment includes a dispersion medium supply source 261, a liquid transfer pump 262, and a dispersion medium flow path 269. The dispersion medium flow path 269 is a supply path for the first liquid LQ from the dispersion medium supply source 261 to the inlet H3 of the container 210. The dispersion medium flow path 269 is, for example, a flexible tube.

[0108] The dispersion medium supply source 261 is, for example, a container containing the first liquid LQ. The liquid delivery pump 262 is located in the middle of the dispersion medium flow path 269. The liquid delivery pump 262 is configured to continuously deliver the first liquid LQ at a predetermined rate. The liquid delivery pump 262 is, for example, a gear pump or a tube pump. The liquid delivery pump 262 is electrically connected to a control device (not shown), and the control device controls the amount of the first liquid LQ supplied per unit time. The dispersion medium flow path 269 may also be further provided with various measuring instruments and valves, similar to the gas supply flow path 49 in the first embodiment.

[0109] The porous body 230 is a rod-shaped porous section. The porous body 230 is placed inside the container 210 and extends along the cylindrical axis of the container 210. Similar to the porous section 130 of the first embodiment, the porous body 230 is made of a cylindrical porous member (e.g., ceramic) and has a plurality of pores that generate suspended matter (in this case, droplets) in the first liquid LQ. A clearance D5 is ensured around the porous body 230, more specifically, between the inner wall surface (side wall) of the container 210 and the outer circumferential surface of the porous body 230. The range of clearance D5 may be the same as the clearance D3 (or clearance D4) of the first embodiment. The second liquid (oil OL) is supplied to the inner circumference of the porous body 230 by the dispersed phase supply mechanism 240.

[0110] The porous body 230 is supported by a support member 221, similar to the rod-shaped body 20 in the first embodiment. The support member 221 is electrically connected to a rocking mechanism 250, which allows the porous body 230 to rock along the cylindrical axis (in this case, in the vertical direction VD), similar to the first embodiment. This causes the porous body 230 supported by the support member 221 to rock along the cylindrical axis, thereby applying an accelerating shear force to the porous body 230. While the porous body 230 is rocking along the cylindrical axis, at least a portion (preferably the whole) of it remains in contact with the first liquid LQ.

[0111] The dispersed phase supply mechanism 240 is a mechanism that continuously supplies fluid (in this case, oil OL) to the porous body 230 at a pressure equal to or greater than the pressure at which droplets can be generated from the pores of the porous body 230 (droplet generation pressure). Oil OL constitutes the dispersed phase (oil phase) of the dispersion liquid EM, and in this case, it is an oil-based solution (e.g., an organic solvent). The type of oil OL is not particularly limited, as it is appropriately selected depending on the desired type of droplets (suspended matter). The dispersed phase supply mechanism 240 of this embodiment includes a dispersed phase supply source 241, a liquid transfer pump 242, and a dispersed phase flow path 249. The dispersed phase flow path 249 is a supply path for oil OL from the dispersed phase supply source 241 to the porous body 230. The dispersed phase flow path 249 is, for example, a flexible tube.

[0112] The dispersed phase supply source 241 is, for example, a container containing oil OL. The liquid delivery pump 242 is, for example, a syringe pump or a diaphragm pump. The liquid delivery pump 242 is configured to continuously deliver oil OL at a predetermined rate. The liquid delivery pump 242 is electrically connected to a control device (not shown), and the control device controls the amount of oil OL supplied per unit time. Although not particularly limited, the ratio of the amount of oil OL (oil phase) delivered from the liquid delivery pump 242 to the amount of the first liquid LQ (aqueous phase) delivered from the dispersion medium supply source 261 is preferably 5:95 to 20:80, and more preferably 10:90 to 40:60, from the viewpoint of generating fine droplets at high density. The dispersed phase flow path 249 may be further provided with various measuring instruments and valve bodies, similar to the gas supply flow path 49 in the first embodiment.

[0113] The rocking mechanism 250 is a mechanism that rocks at least one of the container 210 and the porous body (rod-shaped body) 230 along the cylindrical axis while maintaining the porous body 230 in contact with the first liquid LQ. In this embodiment, the rocking mechanism 250 is a mechanism that rocks at least one of the container 210 and the porous body 230 in a direction toward the bottom wall of the container 210 and in a direction toward the bottom wall (second direction). In this embodiment, the rocking mechanism 250 is a mechanism that rocks the porous body (rod-shaped body) 230 along the cylindrical axis (vertical direction VD) via the support member 221. More specifically, the rocking mechanism 250 is a mechanism that rocks the porous body 230 in a direction toward the bottom wall of the container 210 and in a direction toward the bottom wall. Although not shown in the diagram, the rocking mechanism 250 is configured, similar to the first embodiment described above, to rock the porous body (rod-shaped body) 230 between a first position located above the vertical direction VD and a second position located below the vertical direction VD.

[0114] The oscillating mechanism 250 is electrically connected to a control device (not shown), and the control device switches between driving and stopping. The oscillating conditions of the porous body 230, such as the oscillating frequency and the stroke length in the direction of the cylindrical axis, may be stored in advance in the control device. The oscillating conditions of the porous body 230 are preferably adjusted as appropriate depending on the properties of the desired dispersion liquid EM, such as the type of the first liquid LQ and the size of the desired droplets (suspended matter). Furthermore, according to the inventors' studies, the suitable oscillating conditions may also differ depending on, for example, the clearance D5 and the pore diameter of the porous body 230. Therefore, although not particularly limited, in some embodiments, the oscillating conditions of the porous body 230, such as the oscillating frequency and the stroke length in the direction of the cylindrical axis, are preferably the same as in the first embodiment described above. The control device is configured here to continuously supply oil OL to the porous body 230 regardless of the operation of the oscillating mechanism 250. However, in other embodiments, the control device may have a dispersed phase supply control unit configured to control the dispersed phase supply mechanism 240 in accordance with the operation of the oscillating mechanism 250 and to adjust the supply of oil OL to the porous body 230, similar to the first embodiment described above.

[0115] The recovery mechanism 270 is a mechanism for recovering the dispersed EM produced in the containment space of the container 210. The recovery mechanism 270 of this embodiment includes a recovery channel 271, a liquid transfer pump 272, and a recovery container 273. The upstream end of the recovery channel 271 is located in the containment space of the container 210. The recovery channel 271 is the channel for the dispersed EM from the containment space of the container 210 to the recovery container 273. The recovery channel 271 is, for example, a flexible tube. The liquid transfer pump 272 is, for example, a tube pump. The liquid transfer pump 272 is electrically connected to a control device (not shown), and the amount of dispersed EM recovered per unit time is controlled by the control device. The downstream end 271e of the recovery channel 271 is located in the internal space of the recovery container 273. The dispersed EM passes through the recovery channel 271 and is recovered into the recovery container 273.

[0116] In the manufacturing apparatus 200 disclosed herein, first, the porous body 230 is housed in the container 210. Next, when the liquid delivery pump 262 of the dispersion medium supply mechanism 260 is driven, a first liquid LQ is supplied to the housing space of the container 210 at a predetermined supply rate. Also, when the liquid delivery pump 242 of the dispersion phase supply mechanism 240 is driven, oil OL is supplied to the inner circumference of the porous body 230 at a predetermined supply rate. In this state, by oscillating the porous body 230 under predetermined oscillating conditions using the oscillating mechanism 250, an accelerating shear force can be generated in the porous body 230. As a result, the oil OL supplied to the porous body 230 is released into the first liquid LQ as fine droplets (suspended matter) from multiple pores of the porous body 230. This allows for the production of a dispersion liquid EM. This method allows for the efficient generation of fine droplets in the liquid LQ.

[0117] Next, a test example relating to a second embodiment of the technology disclosed herein will be described. Note that the test example shown below is not intended to limit the technology disclosed herein.

[0118] <Test 4> In Test 4, a dispersion of EM was produced using the manufacturing apparatus 200 according to the second embodiment. The configuration of the apparatus used in Test 1 is shown in Figure 11. Therefore, the reference numbers assigned to each name of the apparatus below are the numbers shown in Figure 11.

[0119] -Examples 27-32- First, a bottomed cylindrical container 210 with a length in the axial direction of the cylinder 120 mm and a hollow cylindrical rod-shaped body (porous body 230) with a diameter of 12 mm and a length in the axial direction of the cylinder 10 mm were prepared. Two types of porous body 230 were prepared, each having the average pore size shown in the corresponding column of Table 4 and mainly composed of alumina. Next, a support member 221 was attached to the upper end of the porous body 230 and it was placed in the containment space of the container 210. A clearance D5 of 1 mm was secured around the porous body 230, in this case between it and the inner wall surface of the container 210, as shown in the corresponding column of Table 4.

[0120] Next, the liquid transfer pump 262 of the dispersion medium supply mechanism 260 was controlled to supply the first liquid LQ (aqueous phase, continuous phase) into the containment space of the container 210 at the supply rate shown in the corresponding column of Table 4. In this case, a 1.0 wt% aqueous solution of sodium dodecyl sulfate was used as the first liquid LQ. Furthermore, the liquid transfer pump 242 of the dispersion phase supply mechanism 240 was controlled to supply oil OL (oil phase, dispersed phase) to the inner circumference of the porous body 230 at the supply rate shown in the corresponding column of Table 4. In this case, methyl laurate was used as the oil OL. The oil OL was supplied continuously (valve opening 100%). The flow rate between the first liquid LQ and oil OL was 20 mL / min.

[0121] Next, the oscillation mechanism 250 was controlled to oscillate the porous body 230 in the vertical direction VD at the oscillation frequency shown in the corresponding column of Table 4, thereby applying an accelerating shear force to the porous body 230. This oscillation frequency was adjusted so that the shear force was about the same as that of the comparative example (Non-Patent Literature 1) described later. The vertical stroke length of the porous body 230 was kept constant at 40 mm. In this manner, droplets of oil OL were generated from the pores of the porous body 230 into the first liquid LQ, and a dispersion liquid EM containing the droplets was obtained.

[0122] Then, the fine droplets contained in the obtained dispersion EM were photographed with an optical microscope, and, as in Experiment 1 described above, the average diameter (μm) of the droplets contained in the dispersion EM was calculated using the image analysis software "ImageJ". The results are shown in the corresponding column of Table 4.

[0123] [Table 4]

[0124] -Comparative Examples 1-6- For reference, Table 4 shows the manufacturing conditions described in Non-Patent Document 1 and the average droplet diameter in the dispersion (Comparative Examples 1-6) read from the graph. While a detailed explanation is omitted, the apparatus disclosed in Non-Patent Document 1 is a so-called double-cylinder rotary type, in which a porous body contained in a container is configured to rotate at the rotational speed (constant velocity) shown in the corresponding column of Table 4 by a rotation mechanism. In other words, it is configured to apply centrifugal force (constant velocity shear force) to the porous body by the rotation mechanism. Unlike the technology disclosed herein, the apparatus disclosed in Non-Patent Document 1 does not have a rocking mechanism.

[0125] Figures 12(A) to (F) are graphs showing the frequency distribution of droplet diameters for Examples 27 to 32, respectively. Figure 13 is a graph comparing the results of Examples 27 to 32 with those of Comparative Examples 1 to 6. In Figure 13, the left axis shows the average diameter, and the right axis shows the CV value. As shown in Figure 1 and Table 4, in Examples 27 to 32, in which accelerated shear force was applied to the porous body 230 by the oscillating mechanism 250, it was found that droplets could be made finer at a lower rotational speed (shear force) compared to Comparative Examples 1 to 6, in which constant-velocity shear force was applied to the porous body. The reason for this is thought to be that in the technology disclosed herein, by applying accelerated shear to the porous body 230, the shear force was applied to the vicinity of the surface of the porous body 230.

[0126] The manufacturing apparatus 200 of the second embodiment disclosed herein (a manufacturing apparatus for a dispersion liquid EM containing fine droplets) has been described above. However, the manufacturing apparatus disclosed herein is not limited thereto and may include other modifications.

[0127] As described above, specific embodiments of the technology disclosed herein include those described in the following sections.

[0128] [Item 1] A apparatus for producing a dispersion liquid in which fluid suspended matter is dispersed in a liquid as a dispersion medium, comprising: a bottomed cylindrical container for containing the liquid; a rod-shaped body disposed inside the container and extending along the cylindrical axis direction of the container; a porous portion provided on the portion of at least one of the container and the rod-shaped body that is in contact with the liquid and having a plurality of pores for generating the suspended matter in the liquid; a fluid supply mechanism for supplying the fluid to the porous portion at a pressure equal to or greater than the suspended matter generation pressure that can generate the suspended matter from the pores; and a rocking mechanism for rocking at least one of the container and the rod-shaped body along the cylindrical axis direction while maintaining the porous portion in contact with the liquid. [Item 2] The manufacturing apparatus according to Item 1, wherein the rocking mechanism is configured to rock at least one of the container and the rod-shaped body between a first position located on the vertically upward side and a second position located on the vertically downward side. [Item 3] The manufacturing apparatus according to Item 2, wherein the fluid supply mechanism is configured to supply gas as the fluid, and the suspended matter is bubbles. [Clause 4] The manufacturing apparatus according to Claim 3, further comprising a control device connected to the fluid supply mechanism and the rocking mechanism, wherein the control device has a gas supply control unit that controls the fluid supply mechanism in accordance with the operation of the rocking mechanism and adjusts the supply of the gas to the porous section. [Clause 5] The manufacturing apparatus according to Clause 3 or 4, wherein the rocking mechanism is a mechanism that rocks at least one of the container and the rod-shaped body toward the bottom wall of the container and toward the rod-shaped body and toward the bottom wall of the container and toward the rod-shaped body, and the gas supply control unit controls the fluid supply mechanism to supply the porous portion with the gas at or above the floating matter generation pressure when at least one of the container and the rod-shaped body moves toward the first direction. [Clause 6] The manufacturing apparatus according to Clause 5, wherein the gas supply control unit controls the fluid supply mechanism to reduce the pressure of the gas supplied to the porous portion to less than the floating matter generation pressure during at least a portion of the period during which at least one of the container and the rod-shaped body moves in the second direction. [Clause 7] The manufacturing apparatus according to Clause 5 or 6, wherein the gas supply control unit controls the fluid supply mechanism to reduce the pressure of the gas supplied to the porous portion to less than the floating matter generation pressure during a portion of the period in which at least one of the container and the rod-shaped body moves in the first direction. [Clause 8] The manufacturing apparatus according to any one of Clauses 5 to 7, wherein the gas supply control unit controls the fluid supply mechanism to supply the gas to the porous portion at a pressure equal to or greater than the floating matter generation pressure only during the period when at least one of the container and the rod-shaped body is moving in the first direction. [Item 9] The manufacturing apparatus according to any one of items 2 to 8, wherein the clearance around the rod-shaped body in the radial direction intersecting the cylindrical axis direction is 5 mm or less. [Clause 10] The manufacturing apparatus according to any one of Clauses 1 to 9, wherein the oscillation mechanism is configured to be switchable between a first oscillation frequency and a second oscillation frequency that is higher than the first oscillation frequency. [Item 11] The manufacturing apparatus according to any one of items 1 to 10, wherein the porous portion is provided on the rod-shaped body, and the oscillating mechanism is configured to oscillate the rod-shaped body in the direction of the cylindrical axis. [Item 12] The manufacturing apparatus according to any one of items 1 to 11, further comprising a cylindrical partition member arranged around the rod-shaped body and separating the outer surface of the rod-shaped body from the inner wall surface of the container. [Clause 13] The manufacturing apparatus according to any one of Clauses 2 to 12, wherein the fluid supply mechanism comprises a gas supply channel and a pump, the pump being configured to pulsate the gas in the gas supply channel to the extent that bubbles can be generated in the porous portion. [Clause 14] The manufacturing apparatus according to Clause 1 or 2, wherein the fluid supply mechanism is configured to supply a second liquid that does not dissolve in the dispersion medium as the fluid, and the suspended matter is fine droplets of the second liquid. [Item 15] A method for producing a dispersion, comprising producing the dispersion using the manufacturing apparatus described in any one of items 1 to 14.

[0129] The technologies disclosed herein have been described above, but these are merely examples and do not limit the scope of the claims. The technologies disclosed herein may be modified in various ways without departing from their essence. [Explanation of Symbols]

[0130] 100: Manufacturing equipment 10, 110: Container 112: Partition member 20, 120: Rod-shaped body 30, 130: Porous part 40, 140: Gas supply mechanism 50: Oscillating mechanism 60: Bubble measurement section 70: Control device 72: Gas supply control unit 73: Oscillating control unit D3, D4, D5: Clearance DL: Dispersion liquid LQ: Liquid G: Gas P1: 1st position P2: 2nd position 200: Manufacturing equipment 210: Container 230: Porous material (rod-shaped porous part) 240: Dispersed phase supply mechanism 250: Oscillating mechanism 260:Dispersion medium supply mechanism 270: Recovery mechanism EM: Emulsion (dispersion) LQ: First liquid OL: Oil

Claims

1. An apparatus for producing a dispersion liquid in which fluid suspended matter is dispersed in a liquid acting as a dispersion medium, A bottomed cylindrical container for containing the aforementioned liquid, A rod-shaped body is placed inside the container and extends along the cylindrical axis of the container, A porous portion is provided in the part of at least one of the container and the rod-shaped body that comes into contact with the liquid, and has a plurality of pores that generate the suspended matter in the liquid, A fluid supply mechanism supplies the fluid to the porous portion at a pressure equal to or greater than the pressure required to generate suspended matter from the pores, A rocking mechanism that rocks at least one of the container and the rod-shaped body along the cylindrical axis while maintaining the porous portion in contact with the liquid, A apparatus for producing dispersions, equipped with the following features.

2. The rocking mechanism is configured to rock at least one of the container and the rod-shaped body between a first position located vertically upward and a second position located vertically downward. The manufacturing apparatus according to claim 1.

3. The fluid supply mechanism is configured to supply gas as the fluid, The floating matter is a bubble. The manufacturing apparatus according to claim 2.

4. The system further comprises a control device connected to the fluid supply mechanism and the rocking mechanism, The control device includes a gas supply control unit that controls the fluid supply mechanism in accordance with the operation of the oscillating mechanism and adjusts the supply of the gas to the porous section. The manufacturing apparatus according to claim 3.

5. The rocking mechanism is a mechanism that rocks at least one of the container and the rod-shaped body in a first direction in which the bottom wall of the container and the rod-shaped body move closer together, and in a second direction in which the bottom wall of the container and the rod-shaped body move further apart. The gas supply control unit controls the fluid supply mechanism to supply the porous portion with the gas at or above the floating matter generation pressure when at least one of the container and the rod-shaped body moves in the first direction. The manufacturing apparatus according to claim 4.

6. The gas supply control unit controls the fluid supply mechanism such that the pressure of the gas supplied to the porous portion is less than the floating matter generation pressure during at least a portion of the period during which at least one of the container and the rod-shaped body moves in the second direction. The manufacturing apparatus according to claim 5.

7. The gas supply control unit controls the fluid supply mechanism such that, during a portion of the period in which at least one of the container and the rod-shaped body moves in the first direction, the pressure of the gas supplied to the porous portion is less than the pressure of suspended matter generation. The manufacturing apparatus according to claim 5.

8. The gas supply control unit controls the fluid supply mechanism to supply the porous portion with the gas at or above the floating matter generation pressure only during the period when at least one of the container and the rod-shaped body is moving in the first direction. The manufacturing apparatus according to claim 7.

9. In the radial direction intersecting the cylindrical axis, the clearance around the rod-shaped body is 5 mm or less. The manufacturing apparatus according to claim 2.

10. The oscillation mechanism is configured to be switchable between a first oscillation frequency and a second oscillation frequency that is higher than the first oscillation frequency. The manufacturing apparatus according to claim 1.

11. The porous portion is provided on the rod-shaped body, The rocking mechanism is configured to rock the rod-shaped body in the direction of the cylindrical axis. The manufacturing apparatus according to claim 1.

12. The container further comprises a cylindrical partition member arranged around the rod-shaped body, which separates the outer surface of the rod-shaped body from the inner wall surface of the container. The manufacturing apparatus according to claim 9.

13. The fluid supply mechanism comprises a gas supply channel and a pump. The pump is configured to pulsate the gas in the gas supply channel within a range that can generate bubbles in the porous portion. The manufacturing apparatus according to claim 3.

14. The fluid supply mechanism is configured to supply a second liquid that does not dissolve in the dispersion medium as the fluid. The suspended matter is a fine droplet of the second liquid. The manufacturing apparatus according to claim 2.

15. A method for producing a dispersion, comprising producing the dispersion using the manufacturing apparatus described in any one of claims 1 to 14.

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