Ultrafine bubble-containing liquid manufacturing method, ultrafine bubble-containing liquid manufacturing device, and set of ultrafine bubble-containing liquid manufacturing device and collision member

Abstract

Provided is a method for producing an ultrafine bubble-containing liquid, which can produce a high-concentration ultrafine bubble-containing liquid.SOLUTION: A method for producing an ultrafine bubble-containing liquid, the method including a supplying step of supplying a liquid to a liquid supplied region in which an ejection orifice forming member having an ejection orifice is arranged, and an ejecting step of pressurizing the liquid supplied to the liquid supplied region and ejecting the liquid as a liquid droplet from the ejection orifice, wherein the ejecting step is a step of ejecting the liquid droplet so as to collide with a collision member, and a flying speed of the liquid droplet at a time of collision with the collision member is 1m / s or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing an ultra-fine bubble-containing liquid, an apparatus for producing an ultra-fine bubble-containing liquid, and a set of an apparatus for producing an ultra-fine bubble-containing liquid and a collision member. [Background technology]

[0002] Liquids containing ultrafine bubbles (UFB) with a diameter of less than 1.0 μm are known to have good cleaning and sterilizing properties. In order to maintain the effectiveness of their cleaning and sterilizing properties, it is desirable for the UFB-containing liquid to remain within the liquid without floating to the surface. In order to produce a highly concentrated UFB-containing liquid, it is considered preferable to avoid the generation of bubbles with a diameter of 1.0 μm or more, and in recent years, the inkjet discharge method has been adopted as a method for producing a UFB-containing liquid.

[0003] For example, Patent Document 1 addresses the issue of providing an apparatus and method for generating ozone-containing UFB liquid that can generate highly concentrated ozone-containing UFB liquid that can be stored for a long period of time. As a means for solving this issue, the patent document discloses an apparatus for generating ozone-containing ultrafine bubble liquid that includes: ultrafine bubble generating means that generates ultrafine bubble liquid containing ultrafine bubbles by applying energy to a liquid and discharging the liquid from a minute diameter outlet; and irradiation means that irradiates the ultrafine bubble liquid with ultraviolet light (see Patent Document 1). For example, Patent Document 2 discloses a method for producing an ultra-fine bubble-containing liquid, which aims to stably produce an ultra-fine bubble-containing liquid even when using a liquid containing a variety of additives or a liquid whose main component is an organic solvent, and as a means for solving this problem, the method includes a supply step of supplying a liquid containing at least one substance selected from a specific group to a liquid supply region having an outlet-forming member with a minute-diameter outlet formed therein, and a discharge step of pressurizing the liquid supplied to the liquid supply region with a pressurizing means in contact with the liquid, thereby discharging the liquid from the outlet in the form of droplets (see Patent Document 2). Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a method for producing a liquid containing ultra-fine bubbles, which can produce a liquid containing ultra-fine bubbles at a high concentration. [Means for solving the problem]

[0005] The method for producing an ultra-fine bubble-containing liquid of the present invention as a means for solving the above problems comprises the steps of: a supply step of supplying the liquid to a liquid supply region in which a discharge port forming member having a discharge port is disposed; a discharge step of pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets; A method for producing an ultra-fine bubble-containing liquid, comprising: The discharging step is a step of discharging droplets so as to collide with a collision member, and the flying speed of the droplets when they collide with the collision member is 1 m / s or more. [Effects of the Invention]

[0006] According to the present invention, there is provided a method for producing a liquid containing ultra-fine bubbles, which can produce a liquid containing ultra-fine bubbles at a high concentration. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic cross-sectional view showing an example of an apparatus for producing a UFB-containing liquid according to the present invention. [Figure 2] 1 is a schematic cross-sectional view showing an example of a liquid ejection head in a manufacturing apparatus for a UFB-containing liquid of the present invention. [Figure 3A] FIG. 10 is a diagram showing an example of a driving pulse during a discharge process in the present invention. [Figure 3B] 10A and 10B are diagrams showing other examples of drive pulses during the ejection process in the present invention. [Figure 4] 1 is a schematic cross-sectional view showing an example of a state in the vicinity of a collision member in a method for producing a UFB-containing liquid of the present invention. [Figure 5] FIG. 4 is a schematic diagram for explaining a method for measuring the Young's modulus of the support member. [Figure 6] 1 is a block diagram illustrating an example of a control unit of the manufacturing apparatus 100 for producing a UFB-containing liquid according to the present invention. [Figure 7] 1 is a schematic diagram showing one embodiment of an apparatus for producing a UFB-containing liquid according to the present invention. [Figure 8] 1 is a schematic diagram showing another embodiment of the apparatus for producing a UFB-containing liquid according to the present invention. [Figure 9] 3 is a block diagram illustrating an example of a control unit of the manufacturing apparatus 300 for a UFB-containing liquid according to the present invention. FIG. [Figure 10] FIG. 10 is a diagram for explaining a driving waveform used in the example. [Figure 11] 1 is a graph showing the measurement results of the number density of nanoparticles in Examples and Comparative Examples. [Figure 12] 10 is a diagram showing a state in which a droplet 4 ejected by a liquid ejection head 20 collides with skin 63. FIG. [Figure 13] 10 is a diagram showing a state in which a droplet 4 ejected by a liquid ejection head 20 collides with a vegetable 64. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the prior art including the inventions described in Patent Documents 1 and 2, there was room for improvement in the concentration of ultra-fine bubbles in the ultra-fine bubble-containing liquid.

[0009] The method for producing an ultra-fine bubble-containing liquid of the present invention can fully resolve the various concerns of the prior art. More specifically, it can realize a method for producing an ultra-fine bubble-containing liquid with a high concentration.

[0010] The present invention will be described in detail below.

[0011] (Method for producing ultra-fine bubble-containing liquid, and apparatus for producing ultra-fine bubble-containing liquid) The method for producing ultra-fine bubble-containing liquid of the present invention includes a supplying step of supplying liquid to a liquid supply region in which a discharge port-forming member having a discharge port is disposed, and a discharging step of pressurizing the liquid supplied to the liquid supply region and discharging the liquid as droplets from the discharge port.The method may also include, as necessary, a fine bubble generating step of passing the liquid through a bubble generating section to generate fine bubbles, a gas-dissolved liquid generating step of passing the liquid through a gas dissolving section to generate a gas-dissolved liquid, an ultraviolet irradiation step of irradiating ultraviolet light onto at least one of the liquid, the droplets, and the gas taken up in the ultra-fine bubble-containing liquid, and other steps.

[0012] The apparatus for producing ultra-fine bubble-containing liquid of the present invention comprises supply means for supplying liquid to a liquid supply region in which a discharge port-forming member having a discharge port is disposed, and discharge means for pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets, wherein the discharge means discharges the droplets so as to collide with a collision member, and the apparatus for producing ultra-fine bubble-containing liquid comprises moving means for moving the discharge means and the collision member so that the flight speed of the droplets upon collision with the collision member is 1 m / s or more, and may optionally comprise fine bubble generating means for generating fine bubbles, gas-dissolved liquid generating means for generating a gas-dissolved liquid, ultraviolet irradiating means for irradiating ultraviolet light onto at least one of the liquid, droplets, and gas taken up in the ultra-fine bubble-containing liquid, and other means.

[0013] The method for producing an ultra-fine bubble-containing liquid can be suitably carried out by an apparatus for producing an ultra-fine bubble-containing liquid, the supplying step can be suitably carried out by a supply means, the discharging step can be suitably carried out by a discharging means, the fine bubble generating step can be suitably carried out by a fine bubble generating means, the gas-dissolved liquid generating step can be suitably carried out by a gas-dissolved liquid generating means, the ultraviolet ray irradiation step can be suitably carried out by an ultraviolet ray irradiation means, and the other steps can be suitably carried out by other means.

[0014] In this specification, "ultra-fine bubbles" may be referred to as "UFB."

[0015] The UFB-containing solution obtained by the method for producing a UFB-containing solution of the present invention has a higher UFB concentration than conventional solutions, and therefore has excellent effects obtained by UFB, such as sterilizing power and cleaning power. In this specification, the term "high concentration" is not particularly limited and can be appropriately selected depending on the purpose. 8 It is preferable that the density is particles / mL or more.

[0016] Here, the manufacturing apparatus for the UFB-containing liquid of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In each drawing, the same components are denoted by the same reference numerals, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and the number, position, shape, etc. may be any number, position, shape, etc. that is preferable for implementing the present invention.

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of an apparatus for producing a UFB-containing liquid according to the present invention. The manufacturing apparatus 100 for manufacturing a UFB-containing liquid includes a supply unit 10 as a liquid supply means for supplying the liquid L10, a liquid ejection head 20 as an ejection means, and an ultraviolet irradiation means 5 for irradiating ultraviolet light 51 onto droplets 4 ejected from the ejection means.

[0018] The supply unit 10 supplies the liquid L10, which has been supplied into the supply unit 10 by a pump or the like, to the liquid ejection head 20 via a supply flow path 12. The liquid ejection head 20 pressurizes the liquid L10 supplied from the supply unit 10 and ejects it as droplets 4. At this time, the droplets 4 are ejected so as to collide with the collision member 61. Of the liquid L10 supplied to the liquid ejection head 20, the liquid L10 that has not been used to eject droplets may be returned to the supply unit 10 via the recovery flow path 13 by a pump or the like (not shown), and circulated. Also, the liquid ejection head 20 does not need to be equipped with the above-mentioned circulation mechanism.

[0019] The droplets 4 discharged from the droplet discharge head 20 are irradiated with ultraviolet light 51 from the ultraviolet irradiation means 5 .

[0020] The droplets 4 irradiated with ultraviolet light 51 from the ultraviolet light irradiation means 5 are caused to collide with a collision member 61 supported by a collision support member 62, thereby obtaining a UFB-containing liquid.

[0021] -liquid- The liquid L10 is not particularly limited as long as it can generate UFB within the liquid and can be appropriately selected depending on the purpose, and examples thereof include water, ozone water, hydrogen peroxide water, etc. Among these, hydrogen peroxide water is preferred from the viewpoint of enhancing the sterilizing power of the UFB-containing liquid.

[0022] The liquid may contain a gas. That is, the liquid may be a liquid containing microbubbles generated by bubbling a gas through the liquid, or a gas-dissolved liquid in which a gas is dissolved in a liquid. When a liquid containing microbubbles is used as the liquid to be supplied in the supplying step and the discharging step, the microbubbles are broken down into smaller pieces when colliding with the collision member, resulting in a highly concentrated UFB-containing liquid. When a gas-dissolved liquid is used as the liquid for the supplying process and the discharging process, the pressure fluctuations during discharging cause the dissolved gas components and liquid to evaporate, generating microbubbles and UFBs, resulting in a highly concentrated UFB-containing liquid.

[0023] The liquid containing microbubbles can be generated by a fine bubble generating process (means). The fine bubble generating means is not particularly limited and can be appropriately selected depending on the purpose, and an example thereof is U20H (manufactured by Shibata Co., Ltd.).

[0024] The gas-dissolved liquid can be generated by a gas-dissolved liquid generation step (means). The gas-dissolved liquid generation means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a voltage dissolution method and a bubbling method. The method for measuring the amount of dissolved gas in a liquid is not particularly limited and can be appropriately selected depending on the purpose. For example, the amount of dissolved gas can be measured using a handy DO meter TOX-999B (manufactured by Toko Chemical Research Institute Co., Ltd.).

[0025] There are no particular restrictions on the gas to be bubbled into the liquid and the gas to be dissolved in the liquid, and they can be selected appropriately depending on the purpose, but ozone is preferred from the viewpoint of improving the sterilizing power of the UFB-containing liquid.

[0026] The viscosity of the liquid is not particularly limited and can be selected appropriately depending on the purpose as long as it can be discharged from the liquid discharge head, but it is preferable that the viscosity is 30 mPa s or less at room temperature and normal pressure. Note that liquids whose viscosity can be reduced to 30 mPa s or less by heating or cooling may also be used. The method for measuring the viscosity of a liquid is not particularly limited and can be appropriately selected depending on the purpose. For example, the viscosity can be measured using a DV2T (manufactured by Brookfield).

[0027] The surface tension of the liquid is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably 80 mN / m or less. The method for measuring the surface tension of a liquid is not particularly limited and can be appropriately selected depending on the purpose. For example, the surface tension can be measured using a DY-700 (manufactured by Kyowa Interface Science Co., Ltd.).

[0028] -Liquid ejection head- A liquid ejection head is a functional component that ejects and sprays liquid from a nozzle. Examples of energy sources for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators that consist of a vibration plate and an opposing electrode.

[0029] Here, the liquid discharge head will be described in detail with reference to Fig. 2. Fig. 2 is a schematic cross-sectional view showing an example of a liquid discharge head in the manufacturing apparatus for the UFB-containing liquid of the present invention.

[0030] [Figure 2] The liquid ejection head 20 has a flow path forming member 21 that forms a flow path 22 from a liquid inlet 22a to a liquid outlet 22b. The liquid inlet 22a is connected to the supply flow path 12 shown in Figure 1, and the liquid outlet 22b is connected to the recovery flow path 13 shown in Figure 1. A plate-shaped discharge port forming member 25 having a plurality of minute discharge ports 26 formed therein is provided in a part of the flow path forming member 21, and an element holding member 27 is provided at a position facing the discharge port forming member 25. A plurality of piezoelectric elements (pressure means) 28 are provided on the element holding member 27 facing the discharge ports 26.

[0031] The diameter of the outlet 26 is not particularly limited as long as it can produce UFBs in the method for producing a UFB-containing liquid of the present invention, and can be selected appropriately depending on the purpose, but it is preferable that it be a very small diameter, i.e., 0.1 μm or more and 100 μm or less. The number of outlets 26 formed in the outlet forming member 25 is not particularly limited and can be selected appropriately depending on the purpose, and may be single or multiple, but it is preferable to provide one piezoelectric element for one outlet.

[0032] The piezoelectric element 28 is also called a piezo element, and is in contact with the liquid L10 filled in the flow path 22, which is a liquid supply region, and is displaced toward the discharge port 26 by a drive voltage (drive pulse) applied from a driving means (not shown), thereby directly pressurizing the liquid L10. This pressure causes the liquid L10 filled in the flow path 22 and the discharge port 26 to be discharged from the discharge port 26 as droplets 4.

[0033] [Figures 3A-3B] The drive voltage (drive pulse) may be generated by a drive waveform generating unit. The drive waveform is not particularly limited and can be appropriately selected depending on the purpose as long as it allows droplets to be ejected from the liquid ejection head 20. Examples include the drive waveforms shown in FIGS. 3A and 3B. Among these, the drive waveform shown in FIG. 3B is preferred from the viewpoint of being able to stably eject droplets with a relatively high surface tension. Note that FIG. 3A is a diagram showing an example of a drive pulse during the ejection process of the present invention, and FIG. 3B is a diagram showing another example of a drive pulse during the ejection process of the present invention.

[0034] 2, droplets 4 ejected from the ejection ports 26 of the liquid ejection head 20 contain microbubbles 41 and UFBs 42. In this specification, "microbubbles" refer to bubbles with a diameter of 1 μm or more and less than 100 μm. Also, in this specification, "UFBs" refer to bubbles with a diameter of less than 1 μm. The mechanism by which the microbubbles 41 and UFBs 42 are contained in the droplets 4 is presumed to be as follows. When the liquid L10 is ejected as droplets 4 from the ejection ports 26 of the liquid ejection head 20, shear stress acts on the liquid L10 between the liquid L10 and the wall surface surrounding the ejection ports 26. Since the liquid L10 immediately becomes droplets 4 and flies, the liquid L10, released from the shear stress, is subjected to a large pressure fluctuation in a short period of time. It is presumed that this large pressure fluctuation causes a phase change of the dissolved gas in the liquid L10, changing it to a gaseous state, thereby forming the microbubbles 41 and UFBs 42.

[0035] The volume of the liquid ejected from the liquid ejection head 20 is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 1 pL or more and 10 pL or less.

[0036] The flying speed of the droplets 4 when they collide with the collision member 61 is 1 m / s or more, preferably 1 m / s or more and 15 m / s or less, from the viewpoint of efficiently generating UFB.

[0037] The ejection direction of the droplets 4 in the ejection process is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of efficiently generating UFB, it is preferable that the ejection direction be perpendicular to the collision surface of the droplets 4 on the collision member 61.

[0038] -Ultraviolet irradiation process- The method for producing a UFB-containing liquid of the present invention may include an ultraviolet ray irradiation step of irradiating droplets 4 ejected from a liquid ejection head 20 with ultraviolet rays 51, as shown in FIG.

[0039] The ultraviolet irradiation step may be performed using multiple ultraviolet irradiation means with different wavelengths. For example, by irradiating the droplets 4 with ultraviolet light having a wavelength of approximately 185 nm, the dissolved oxygen contained in the droplets 4 can be converted into ozone, thereby improving the sterilization effect of the UFB-containing liquid. Furthermore, by continuously irradiating the droplets 4 with ultraviolet light having a wavelength of approximately 254 nm, a UFB-containing liquid containing active oxygen can be produced, and further sterilization effects can be expected.

[0040] From the viewpoint of generating ozone or active oxygen from oxygen, the target to be irradiated with ultraviolet light is not limited to the droplets shown in FIG. 1 , but may be, for example, a liquid before being subjected to the supplying process or the discharging process, or a gas that is incorporated into the UFB-containing liquid. Here, the term "gas incorporated into the UFB-containing liquid" in this specification refers to gas contained in the UFB-containing liquid. The state of the gas is not particularly limited and can be appropriately selected depending on the purpose. For example, the gas may be dissolved in the liquid or may be in a bubble state. Examples of gases incorporated into the UFB-containing liquid include gases present between the discharge port and the collision member during the discharge process, gases used in the fine bubble generation process, and gases used in the gas-dissolved liquid generation process.

[0041] The ultraviolet irradiating means for carrying out the ultraviolet irradiating step is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include an LED (light-emitting diode).

[0042] [Figure 4] - Collision components - Here, the collision member will be specifically described with reference to Fig. 4. Fig. 4 is a schematic cross-sectional view showing an example of the state in the vicinity of the collision member in the method for producing a UFB-containing liquid of the present invention. 4 shows a state in which a droplet 4 ejected by the liquid ejection head 20 collides with a collision member 61. By colliding the droplet 4 with the collision member 61, UFBs 42 are generated by taking in the surrounding gas at the time of collision, and the microbubbles 41 in the droplet 4 can be broken down into smaller pieces, which results in an increase in the concentration of UFBs 42 in the droplet 4.

[0043] The material of the collision member 61 is not particularly limited as long as it can be used to manufacture UFB, and can be appropriately selected depending on the purpose. For example, aluminum can be used. The collision member preferably has a nucleus on its surface. The nucleus is a substance containing carbon atoms, and the diameter of the nucleus is 100 nm or less. Here, the "diameter" refers to the maximum diameter. The substance containing carbon atoms is a substance containing one or more carbon atoms, and may be, for example, an organic compound. The diameter of the nucleus can be confirmed by observation using a SEM (Scanning Electron Microscope) or a TEM (Transmission Electron Microscopy). By having a nucleus on the surface of the collision member, a highly concentrated ultra-fine bubble-containing liquid can be produced more efficiently.

[0044] The shape of the collision member 61 is not particularly limited and can be selected appropriately depending on the purpose, but it is preferable that the droplet collision surface of the collision member 61 is smooth. More specifically, it is preferable that the surface roughness Ra of the droplet collision surface of the collision member 61 is about 0.2 μm. The method for measuring the surface roughness Ra is not particularly limited and can be appropriately selected depending on the purpose. For example, the surface roughness Ra can be measured by image analysis using a laser microscope.

[0045] The size and structure of the collision member 61 are not particularly limited and can be appropriately selected depending on the purpose.

[0046] Specific examples of the collision member 61 include semiconductors and metals, but it may also be skin or vegetables.

[0047] [Figure 5] The Young's modulus of the collision member 61 is not particularly limited and can be appropriately selected depending on the purpose. 2 ) or more, and 70 Gpa (kN / mm 2 ) or more is more preferable. The method for measuring the Young's modulus of the collision member 61 is not particularly limited and can be selected appropriately depending on the purpose. For example, as shown in FIG. 5, a load (PN) is applied to the center of a plate-shaped sample (d mm × b mm × L mm) supported at both ends, and the deflection (h mm) is detected by a differential transformer, and the Young's modulus E (N / m 2 ) can be calculated. Note that Fig. 5 is a schematic diagram for explaining a method for measuring the Young's modulus of the support member.

[0048]

number

[0049] The distance between the discharge port 26 in the liquid discharge head 20 and the collision member 61 is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of increasing the UFB concentration, it is preferably 0.1 mm or more and 30 mm or less, and more preferably 0.5 mm or more and 10 mm or less.

[0050] From the viewpoint of efficiently generating UFB, the collision member 61 may be cooled by a collision member cooling means. The cooling temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably above the freezing point of the liquid and below room temperature (25°C). The collision member cooling means may be provided as another means in the manufacturing apparatus for the UFB-containing liquid, or a separate collision member cooling device may be provided when manufacturing the UFB-containing liquid.

[0051] The collision member 61 may be rotated by a collision member rotating means, such as a spin coater used in spin coating.

[0052] There are no particular restrictions on the contact angle between the collision member 61 and pure water and it can be selected appropriately depending on the purpose, but it is preferable that it be 90° or more from the standpoint of ease of entraining outside air and ease of breaking up entrained air bubbles.

[0053] The collision member 61 may be supported by a collision support member 62. There are no particular restrictions on the material, shape, size, and structure of the collision support member 62, as long as it can support the collision member 61, and they can be selected appropriately depending on the purpose.

[0054] The apparatus for producing ultra-fine bubble-containing liquid of the present invention has a discharging means and a moving means for moving the collision member (or the collision support member that supports it) so that the flight speed of the droplets when they collide with the collision member is 1 m / s or more.

[0055] The method for producing an ultra-fine bubble-containing liquid of the present invention may further include a recovery step of recovering the ultra-fine bubble-containing liquid after the discharge step. The apparatus for producing an ultra-fine bubble-containing liquid of the present invention may further include a recovery means for recovering the ultra-fine bubble-containing liquid. The recovery step is preferably carried out by a recovery means.

[0056] The recovery means is not particularly limited and can be appropriately selected depending on the purpose. For example, a spin coater equipped with a waste liquid recovery mechanism can be used.

[0057] Here, a specific example will be described using Figure 12 when the collision member is skin. Figure 12 is a diagram showing a state in which a droplet 4 ejected by a liquid ejection head 20 collides with skin 63. By causing the droplet 4 to collide with skin 63, UFBs 42 are generated by taking in surrounding gas at the time of collision, and the microbubbles 41 in the droplet 4 can be broken down into smaller particles, resulting in an increase in the concentration of UFBs 42 in the droplet 4. Since the skin 63 has many nuclei on its surface, UFBs 42 are generated at a high concentration.

[0058] Here, a specific example will be described using Figure 13 where the collision member is a vegetable. Figure 13 is a diagram showing a state in which a droplet 4 discharged by a liquid discharge head 20 collides with a vegetable 64. By colliding the droplet 4 with the vegetable 64, UFBs 42 are generated by taking in surrounding gas at the time of collision, and the microbubbles 41 in the droplet 4 can be broken down into smaller particles, resulting in an increase in the concentration of UFBs 42 in the droplet 4. Because the vegetable 64 has many nuclei on its surface, UFBs 42 are generated at a high concentration.

[0059] Here, the control unit of the UFB-containing liquid production apparatus 100 will be described with reference to Fig. 6. Fig. 6 is a block diagram for explaining an example of the control unit of the UFB-containing liquid production apparatus 100 of the present invention.

[0060] [Figure 6] The PC 101 includes a control unit 102 . The control unit 102 may appropriately include a CPU that controls the entire manufacturing apparatus for UFB-containing liquid, a program including a program for causing the CPU to control the operation of the apparatus, a ROM that stores other fixed data, and a RAM that temporarily stores data, etc.

[0061] The control unit 102 controls an ejection control unit 103 that controls the ejection of the droplet ejection head 20, an X-axis servo motor 104 that controls the scanning of the droplet ejection head 20 in the X-axis direction, a Y-axis servo motor 105 that controls the scanning of the droplet ejection head 20 in the Y-axis direction, a Z-axis servo motor 106 that controls the scanning of the droplet ejection head 20 in the Z-axis direction, a servo motor 107 that controls an XY plane rotation spindle head 108 that rotates in the XY plane direction relative to the scanning of the collision member 61, an ultraviolet irradiation means 5, and a maintenance unit 7. In this example, the collision member 61 is provided in a spin coater as a collision member rotating means, but the present invention is not limited to this embodiment.

[0062] The maintenance unit 7 is a mechanism for discharging liquid from the nozzle surface of the liquid ejection head 20, and may be, for example, a mechanism including a cap for capping the nozzle surface of the liquid ejection head 20, a suction pump connected to the cap, a wiper member, etc. When performing maintenance operations, the maintenance unit 7 having such a mechanism caps the nozzle surface with the cap and sucks and discharges the liquid from the nozzles by suction using the suction pump.

[0063] Here, embodiments of the method for producing a UFB-containing liquid of the present invention will be described with reference to Figures 7 and 8. Figure 7 is a schematic diagram showing one embodiment of an apparatus for producing a UFB-containing liquid of the present invention, and Figure 8 is a schematic diagram showing another embodiment of an apparatus for producing a UFB-containing liquid of the present invention.

[0064] [Figure 7] In the UFB-containing liquid manufacturing apparatus 200, the liquid stored in the liquid tank 82 is sent through the liquid sending path 821 in the direction of the arrow in Fig. 7 and supplied to the bubble generating unit 71. In response to this, the gas is sent by the pump 81 through the gas sending path 811 in the direction of the arrow in Fig. 7 and supplied to the bubble generating unit 71. At this time, the gas being sent may be irradiated with ultraviolet light from the ultraviolet irradiation means 5. In the bubble generating unit 71, which serves as a fine bubble generating means, gas-derived fine bubbles are generated in the liquid by bubbling the gas through the liquid. The liquid in which the fine bubbles have been generated is supplied to the supply unit 10 of the UFB-containing liquid manufacturing apparatus. Note that the UFB-containing liquid manufacturing apparatus in Fig. 7 has the same configuration as the UFB-containing liquid manufacturing apparatus 100 shown in Fig. 1, and therefore a redundant description will be omitted.

[0065] [Figure 8] In the UFB-containing liquid manufacturing apparatus 300, the liquid stored in the liquid tank 82 is sent via the liquid sending path 821 in the direction of the arrow in FIG. 8 and supplied to the bubble generating unit 72. A liquid having a gas dissolved therein may be used. When the liquid is sent, shear stress is applied to the liquid by the pump 81, and fine bubbles are generated in the liquid by the shear stress. The bubble generating unit 72 has a structure that generates fine bubbles by utilizing the shear stress, and fine bubbles are further generated in the liquid. The liquid being sent may be irradiated with ultraviolet light from the ultraviolet irradiation means 5. The liquid in which fine bubbles have been generated is supplied to supply unit 10 of the UFB-containing liquid manufacturing apparatus. Of the liquid supplied to liquid ejection head 20, the liquid not used for ejecting droplets may be circulated within liquid delivery path 821. Note that the UFB-containing liquid manufacturing apparatus in Fig. 8 has the same configuration as UFB-containing liquid manufacturing apparatus 100 shown in Fig. 1, and therefore a duplicated description will be omitted.

[0066] [Figure 9] 9 is a block diagram for explaining an example of a control unit of the apparatus 300 for producing a UFB-containing liquid of the present invention. Note that the description of the configuration overlapping with that of the apparatus 100 for producing a UFB-containing liquid will be omitted. The control unit 102 controls the bubble generating unit 72 , the pump 81 , the liquid tank 82 , and the circulation unit 109 that controls the ultraviolet irradiation means 5 .

[0067] (A set of an apparatus for producing ultra-fine bubble-containing liquid and a collision member) The present invention provides a set of an apparatus for producing ultra-fine bubble-containing liquid and a collision member, in which the apparatus for producing ultra-fine bubble-containing liquid comprises supply means for supplying liquid to a liquid supply region in which a discharge port-forming member having a discharge port is disposed, and discharge means for pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets, the discharge means discharging the droplets so as to collide with the collision member, and the flight speed of the droplets when they collide with the collision member is 1 m / s or more.

[0068] In the set of the apparatus for producing ultra-fine bubble-containing liquid and the collision member of the present invention, the apparatus for producing ultra-fine bubble-containing liquid may have a fine bubble generating means for generating fine bubbles, and / or a gas-dissolved liquid generating means for generating a gas-dissolved liquid by passing a liquid through a gas dissolving section.

[0069] In the set of the apparatus for producing ultra-fine bubble-containing liquid of the present invention and a collision member, the apparatus for producing ultra-fine bubble-containing liquid may have a collision support member for supporting the collision member, and a moving means for moving the discharge means and the collision member (or the collision support member supporting it) so that the flight speed of the droplets when they collide with the collision member is 1 m / s or more.

[0070] [Application] The UFB-containing liquid obtained by the method for producing a UFB-containing liquid of the present invention can be used, for example, for cleaning semiconductors. [Example]

[0071] The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these examples in any way.

[0072] Example 1 An inkjet head (MH5420, manufactured by Ricoh Co., Ltd.) was filled with pure water, and ejection was carried out under the following conditions to obtain a UFB-containing liquid of Example 1. -Discharge conditions- Dissolved gas species: air Collision material: Aluminum Drive waveform: The drive waveform reduces the voltage from 20V to 4V in 2μs, keeps it at 4V for 2μs, and then rises from 4V to 20V in 2μs (see Figure 10). Drive frequency: 5kHz Droplet flight speed upon impact: 4-5m / s Droplet volume: approx. 8 pL Distance from outlet to impact element: 5mm After collecting approximately 1 mL of the droplets that collided with the collision element, the number density of the nanoparticles was measured using a nanoparticle analysis system, NanoSight Pro (manufactured by Japan Quantum Design Co., Ltd.). The results are shown in Figure 11. The flying speed of the droplets when they collided with the collision member was measured using an EV2500 (manufactured by Ricoh Co., Ltd.) at 1280ch drive and a drive frequency of 5 kHz.

[0073] Example 2 A UFB-containing liquid of Example 2 was obtained in the same manner as in Example 1, except that the distance from the discharge port to the collision member was 10 mm. The number density of the nanoparticles was measured in the same manner as in Example 1. The results are shown in FIG.

[0074] Example 3 A UFB-containing liquid of Example 3 was obtained in the same manner as in Example 1, except that the distance from the discharge port to the collision member was 30 mm. The number density of the nanoparticles was measured in the same manner as in Example 1. The results are shown in Figure 11.

[0075] (Comparative Example 1) The UFB-containing liquid of Comparative Example 1 was obtained in the same manner as in Example 1, except that the distance from the discharge port to the collision member was 45 mm. In Comparative Example 1, the droplets discharged from the discharge port decelerated before colliding with the collision member and reached terminal velocity, so the flight speed at the time of collision was expected to be approximately 0.5 m / s. The number density of the nanoparticles was measured in the same manner as in Example 1. The results are shown in Figure 11.

[0076] The present invention includes, for example, the following aspects. <1> a supply step of supplying the liquid to a liquid supply region in which a discharge port forming member having a discharge port is disposed; a discharge step of pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets; A method for producing an ultra-fine bubble-containing liquid, comprising: The method for producing an ultra-fine bubble-containing liquid is characterized in that the ejection step is a step of ejecting the droplets so as to collide with a collision member, and the flight speed of the droplets when they collide with the collision member is 1 m / s or more. <2> A core is provided on the surface of the collision member, the nucleus is a substance containing carbon atoms, The diameter of the core is 100 nm or less. <1> A method for producing the ultra-fine bubble-containing liquid described in <3> Before the supplying step, A fine bubble generating step of passing the liquid through a bubble generating section to generate fine bubbles. <1> or <2> 1. A method for producing the ultra-fine bubble-containing liquid according to claim 1. <4> Before the supplying step, a gas-dissolved liquid generating step of passing the liquid through a gas dissolver to generate a gas-dissolved liquid; <1> from <3> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <5> an ultraviolet irradiation step of irradiating ultraviolet rays onto at least one of the liquid, the droplets, and the gas entrained in the ultra-fine bubble-containing liquid; <1> from <4> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <6> The ultraviolet irradiation step is carried out by a plurality of ultraviolet irradiation means having different wavelengths. <5> 1. A method for producing the ultra-fine bubble-containing liquid according to claim 1. <7> The distance between the discharge port and the collision member is 10 mm or less. <1> from <6> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <8> the ejection step ejects the droplets in a direction perpendicular to a collision surface of the collision member against which the droplets collide. <1> from <7> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <9> The collision member is cooled by a collision member cooling means. <1> from <8> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <10> The collision member is rotated by a collision member rotating means. <1> from <9> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <11> The Young's modulus of the collision member is 70 GPa or more. <1> from <10> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <12> The contact angle between the collision member and pure water is 90° or more. <1> from <11> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <13> After the discharging step, A recovery step of recovering the ultra-fine bubble-containing liquid. <1> from <12> 1. A method for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims. <14> a supply means for supplying a liquid to a liquid supply region in which a discharge port forming member having a discharge port is disposed; a discharge means for pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets; An apparatus for producing an ultra-fine bubble-containing liquid, comprising: the ejection means is means for ejecting the droplets so as to collide with a collision member, The apparatus for producing ultra-fine bubble-containing liquid is characterized by comprising a discharging means and a moving means for moving the collision member so that the flight speed of the droplets when they collide with the collision member is 1 m / s or more. <15> The apparatus for producing an ultra-fine bubble-containing liquid has a fine bubble generating means for generating fine bubbles. <14> 1. An apparatus for producing an ultra-fine bubble-containing liquid according to claim 1. <16> The apparatus for producing ultra-fine bubble-containing liquid has a gas-dissolved liquid generating means for passing the liquid through a gas dissolving section to generate a gas-dissolved liquid. <14> or <15> 1. An apparatus for producing an ultra-fine bubble-containing liquid according to claim 1. <17> A set of an apparatus for producing ultra-fine bubble-containing liquid and a collision member, The apparatus for producing the ultra-fine bubble-containing liquid comprises: a supply means for supplying a liquid to a liquid supply region in which a discharge port forming member having a discharge port is disposed; a discharge means for pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets, The set of the apparatus for producing ultra-fine bubble-containing liquid and the collision member is characterized in that the discharge means is a means for discharging the droplets so as to collide with the collision member, and the flight speed of the droplets when they collide with the collision member is 1 m / s or more. <18> The apparatus for producing an ultra-fine bubble-containing liquid has a fine bubble generating means for generating fine bubbles. <17> 1. A set of the apparatus for producing an ultra-fine bubble-containing liquid described in 1. and a collision member. <19> The apparatus for producing ultra-fine bubble-containing liquid has a gas-dissolved liquid generating means for passing the liquid through a gas dissolving section to generate a gas-dissolved liquid. <17> or <18> 1. A set of the apparatus for producing an ultra-fine bubble-containing liquid described in 1. and a collision member.

[0077] <1> from <13> The method for producing an ultra-fine bubble-containing liquid according to any one of the methods described above, <14> from <16> The apparatus for producing an ultra-fine bubble-containing liquid according to any one of the preceding claims, and <17> from <19> According to the set of the apparatus for producing ultra-fine bubble-containing liquid and the collision member described in any one of the above, the conventional problems can be solved and the object of the present invention can be achieved. [Explanation of symbols]

[0078] 100 UFB-containing liquid manufacturing equipment L10 liquid 10 Supply section 12 Supply channel 13 Recovery channel 20 Liquid ejection head 4 droplets 41 Microbubbles 42 Ultra Fine Bubbles 5 Ultraviolet irradiation means 51 UV rays 61 Collision member 62 Collision support member [Prior art documents] [Patent documents]

[0079] [Patent Document 1] Japanese Patent Publication No. 2023-058216 [Patent Document 2] Japanese Patent Application Publication No. 2023-068397

Claims

1. a supply step of supplying the liquid to a liquid supply region in which a discharge port forming member having a discharge port is disposed; a discharge step of pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets; A method for producing an ultra-fine bubble-containing liquid, comprising: The method for producing an ultra-fine bubble-containing liquid is characterized in that the ejection step is a step of ejecting the droplets so as to collide with a collision member, and the flight speed of the droplets when they collide with the collision member is 1 m / s or more.

2. A core is provided on the surface of the collision member, the nucleus is a substance containing carbon atoms, 2. The method for producing an ultra-fine bubble-containing liquid according to claim 1, wherein the diameter of the nuclei is 100 nm or less.

3. Before the supplying step, 2. The method for producing an ultra-fine bubble-containing liquid according to claim 1, further comprising a fine bubble generating step of passing the liquid through a bubble generating section to generate fine bubbles.

4. Before the supplying step, 2. The method for producing an ultra-fine bubble-containing liquid according to claim 1, further comprising a gas-dissolved liquid producing step of passing the liquid through a gas dissolver to produce a gas-dissolved liquid.

5. 5. The method for producing an ultra-fine bubble-containing liquid according to claim 1, further comprising an ultraviolet irradiation step of irradiating ultraviolet rays onto at least one of the liquid, the droplets, and the gas to be entrained in the ultra-fine bubble-containing liquid.

6. 6. The method for producing an ultra-fine bubble-containing liquid according to claim 5, wherein the ultraviolet ray irradiation step is carried out by a plurality of ultraviolet ray irradiating means having different wavelengths.

7. 5. The method for producing an ultra-fine bubble-containing liquid according to claim 1, wherein the distance between the discharge port and the collision member is 10 mm or less.

8. 5. The method for producing an ultra-fine bubble-containing liquid according to claim 1, wherein the ejection step ejects the droplets in a direction perpendicular to a collision surface of the collision member against which the droplets collide.

9. The method for producing an ultra-fine bubble-containing liquid according to claim 1 , wherein the collision member is cooled by a collision member cooling means.

10. 5. The method for producing an ultra-fine bubble-containing liquid according to claim 1, wherein the collision member is rotated by a collision member rotating means.

11. 5. The method for producing an ultra-fine bubble-containing liquid according to claim 1, wherein the collision member has a Young's modulus of 70 GPa or more.

12. 5. The method for producing an ultra-fine bubble-containing liquid according to claim 1, wherein the contact angle between the collision member and pure water is 90° or more.

13. After the discharging step, 5. The method for producing an ultra-fine bubble-containing liquid according to claim 1, further comprising a recovery step of recovering the ultra-fine bubble-containing liquid.

14. a supply means for supplying a liquid to a liquid supply region in which a discharge port forming member having a discharge port is disposed; a discharge means for pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets; An apparatus for producing an ultra-fine bubble-containing liquid, comprising: the ejection means is means for ejecting the droplets so as to collide with a collision member, The apparatus for producing ultra-fine bubble-containing liquid is characterized in that it comprises a moving means for moving the discharge means and the collision member so that the flight speed of the droplets when they collide with the collision member is 1 m / s or more.

15. 15. The apparatus for producing ultra-fine bubble-containing liquid according to claim 14, further comprising fine bubble generating means for generating fine bubbles.

16. 16. The apparatus for producing ultra-fine bubble-containing liquid according to claim 14, further comprising a gas-dissolved liquid producing means for producing a gas-dissolved liquid by passing the liquid through a gas dissolving section.

17. A set of an apparatus for producing ultra-fine bubble-containing liquid and a collision member, The apparatus for producing the ultra-fine bubble-containing liquid comprises: a supply means for supplying a liquid to a liquid supply region in which a discharge port forming member having a discharge port is disposed; a discharge means for pressurizing the liquid supplied to the liquid supply region and discharging the liquid from the discharge port as droplets, The set of the apparatus for producing ultra-fine bubble-containing liquid and the collision member is characterized in that the discharge means is a means for discharging the droplets so as to collide with a collision member, and the flight speed of the droplets when they collide with the collision member is 1 m / s or more.

18. 18. A set of an apparatus for producing ultra-fine bubble-containing liquid and a collision member according to claim 17, wherein the apparatus for producing ultra-fine bubble-containing liquid has fine bubble generating means for generating fine bubbles.

19. 19. A set of an apparatus for producing ultra-fine bubble-containing liquid and a collision member according to claim 17 or 18, wherein the apparatus for producing ultra-fine bubble-containing liquid comprises gas-dissolved liquid generating means for generating a gas-dissolved liquid by passing the liquid through a gas dissolving section.

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