Powder Dispersion Device

Abstract

This technology shortens the time required to disperse multiple types of powders in a solvent compared to conventional methods. [Solution] The powder dispersion apparatus comprises a powder holding section that seals and holds multiple types of powders with different properties, a mixing section that mixes the held multiple types of powders, a dispersion section that contains a solvent and generates cavitation in the solvent, and an input section that introduces the mixed multiple types of powders into the solvent where cavitation is occurring. Before introducing the multiple types of powders into the solvent where cavitation is occurring, the multiple types of powders with different properties are pre-mixed in the powder holding section. Therefore, the time required to disperse multiple types of powders in the solvent is shortened compared to conventional techniques in which the same type of powder is introduced into the solvent and stirred, and the powder being transported along with moisture in the atmosphere can be dispersed in the solvent under normal environmental conditions.

Description

Technical Field

[0001] The technology of the present disclosure relates to a powder dispersing device.

Background Art

[0002] The preparation of the slurry of battery materials is carried out by dispersing powder in a liquid by the shear force generated by rotating a stirring propeller in a stirring device having a mixer and a tank. When the stirring propeller rotates in the liquid, the liquid moves at different speeds, thereby generating a shear force. This shear force loosens the aggregation of the powder and uniformly disperses individual particles in the liquid. Related technologies are disclosed in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when powders of different particle sizes are simultaneously mixed into a liquid, depending on the magnitude of the shear force, the powder with a large particle size can be dispersed, but the powder with a small particle size may be difficult to disperse. Therefore, in the prior art, for each type of powder, the same type of powder is put into a solvent and stirred. Thus, the time required to disperse a plurality of types of powders in a solvent becomes long.

[0005] The technology of the present disclosure aims to provide a powder dispersing device capable of shortening the time required to disperse a plurality of types of powders in a solvent compared to the prior art.

Means for Solving the Problems

[0006] To achieve the above objective, a powder dispersion apparatus according to a first aspect of the technology of this disclosure comprises: a powder holding section for sealing and holding a plurality of types of powders having different properties; a mixing section for mixing the held plurality of types of powders; a dispersion section for containing a solvent and generating cavitation in the solvent; and an input section for introducing the mixed plurality of types of powders into the solvent in which cavitation is being generated. [Effects of the Invention]

[0007] In a first aspect of the technology of this disclosure, multiple types of powders with different properties are pre-mixed in a powder holding unit before being added to a solvent in which cavitation is occurring. Therefore, the time required to disperse multiple types of powders in the solvent can be shortened compared to the conventional technology in which the same type of powder is added to the solvent and stirred for each type of powder. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an example of a powder dispersion apparatus 100 according to an embodiment. [Figure 2] Figure 2 is a timing chart showing an example of the operation of each part of the powder dispersion device 100. [Modes for carrying out the invention]

[0009] Embodiments of the technology of this disclosure will be described below with reference to the drawings.

[0010] [composition] Figure 1 is a schematic diagram showing an example of a powder dispersion apparatus 100 according to an embodiment. As shown in Figure 1, the powder dispersion apparatus 100 according to the embodiment includes a powder holding device 10 for holding multiple types of powders with different properties, a mixing device 2434 for mixing the multiple types of powders held, a dispersion device 22 for containing a solvent and generating cavitation in the solvent, an input device 1220 for introducing the mixed multiple types of powders into the solvent where cavitation is occurring, and a control device 55 configured by a computer.

[0011] The powder holding device 10, mixing device 2434, dispersion device 22, and input device 1220 are examples of the "powder holding section," "mixing section," "dispersion section," and "input section" of the technology disclosed herein.

[0012] (Powder holding device 10) The powder holding device 10 comprises a lid 10U located at the top and an opening / closing shutter 10S located at the bottom, which is manually opened and closed by an operator. When the lid 10U is closed and the opening / closing shutter 10S is closed, the inside of the powder holding device 10 is sealed.

[0013] The powder holding device 10 includes a pressure detection sensor 52 for detecting the pressure inside the powder holding device 10, and an opening valve 42 for releasing the seal inside the powder holding device 10 when the pressure detected by the pressure detection sensor 52 is less than or equal to a predetermined value that is below the pressure resistance of the powder holding device 10.

[0014] The pressure detection sensor 52 and the release valve 42 are examples of the "pressure detection unit" and "release unit" of the technology disclosed herein, respectively.

[0015] A knocker or vibrator (not shown) is provided at the bottom of the powder holding device 10 to prevent blockage of the powder.

[0016] (Mixing device 2434) The mixing device 2434 mixes the powders by supplying gas to the various types of powders held in the powder holding device 10.

[0017] Each of the various types of powders in this embodiment is a powder whose properties change when exposed to air. Specifically, they are battery materials (active materials, thickeners, etc.), for example, materials for the slurry of a lithium-ion battery (positive or negative electrode). In addition, sulfide-based solid electrolytes for all solid batteries may also be used.

[0018] Therefore, in the present embodiment, the gas supplied to the plurality of types of powders is processed so as not to contain moisture, specifically, an inert gas (for example, argon, nitrogen, or helium, etc.). Note that the gas processed so as not to contain moisture is not limited to an inert gas, and for example, hydrocarbon gases such as oxygen (O2), carbon dioxide (CO2), hydrogen (H2), chlorine (Cl2), fluorine (F2), methane (CH4), or propane (C3H8) may be used.

[0019] The mixing device 2434 is configured to be able to supply gas from the lower part of the powder holding device 10, supply it intermittently, and supply it from a plurality of locations of the powder holding device 10.

[0020] Specifically, the mixing device 2434 includes an inert gas storage tank 24 and a pump 26 for supplying the inert gas stored in the inert gas storage tank 24 to the powder holding device 10 through open valves 28, 30 and a plurality (for example, 2) of inert gas supply nozzles 32, 34. The inert gas supply nozzles 32, 34 are attached to the lower part of the powder holding device 10, and the inert gas is supplied from the lower part of the powder holding device 10 by the inert gas supply nozzles 32, 34.

[0021] Also, the mixing device 2434 includes a plurality (for example, 2) of inert gas supply nozzles 32, 34. Therefore, the inert gas can be introduced into the plurality of types of powders held by the powder holding device 10 from a plurality of locations.

[0022] Furthermore, the control device 55 preliminarily mixes the powders in the powder holding device 10 by controlling the inert gas supply nozzles 32, 34 so that the inert gas is intermittently supplied to the powder holding device 10.

[0023] As described above, when the pressure of the powder holding device 10 detected by the pressure detection sensor 52 exceeds a predetermined pressure of the powder holding device 10, the release valve 42 is opened, and the seal of the powder holding device 10 is released. As a result, the inert gas inside the powder holding device 10 flows out.

[0024] (Recovery and supply device 3644) The powder holding device 10 includes a recovery and supply device 3644 that recovers the inert gas that has leaked out when the seal of the powder holding device 10 is opened by the release valve 42, and supplies the recovered inert gas to the powder holding device 10. The recovery and supply device 3644 includes a pump 44 driven by a motor 44M to suck up the leaked inert gas, a storage tank 36 for storing the inert gas sucked up by the pump 44, and a pump 40 that supplies the inert gas stored in the storage tank 36 to the powder holding device 10 via the opened valves 38 and 28 and the inert gas supply nozzle 32.

[0025] The recovery and supply device 3644 is an example of a "recovery and supply unit" of the technology of this disclosure.

[0026] (Dispersion device 22) The dispersion device 22 is pre-filled with a solvent (for example, an organic solvent that does not contain water) in which multiple types of powders are dispersed. The dispersion device 22 includes a generation unit (not shown) which is driven by a motor 22M to generate cavitation in the solvent, and a detection sensor 54 which detects the pressure inside the dispersion device 22.

[0027] The dispersion device 22 comprises an introduction device 22I, a tank 22T, and a circulation pump 22P. The introduction device 22I introduces multiple types of powders into a solvent where cavitation is occurring via the tank 22T and the circulation pump 22P. After the multiple types of powders are dispersed in the solvent by the cavitation, a fixing agent is introduced into the solvent in which the multiple types of powders are dispersed.

[0028] The introduction device 22I is an example of an "introduction unit" of the technology of this disclosure.

[0029] (Dosing device 1220) The input device 1220 includes a rotor that is rotated by a motor 14M, and a supply adjustment device 14 that adjusts the amount of multiple types of powders to be added to the solvent by adjusting the rotation speed of the rotor.

[0030] The input device 1220 includes a connecting pipe 16 that guides multiple types of powders, each with an adjusted input amount, to the dispersion device 22, and an input shutter 18 provided on the connecting pipe 16 that is opened and closed by a motor 18M.

[0031] The input device 1220 is located above the supply adjustment device 14 and includes a connecting pipe 12 that is detachably connected to the lower side of the powder holding device 10.

[0032] A rotor is an example of a “rotating body” in the technology of this disclosure.

[0033] [Effect] Next, the operation of the powder dispersion apparatus 100 configured as described above will be explained.

[0034] The worker removes the powder holding device 10 from the connecting pipe 12, and in a glove box with an ultra-low dew point air or inert gas atmosphere of, for example, -80°CDP (dew point temperature) or lower, manually closes the opening / closing shutter 10S, puts multiple types of powder into the powder holding device 10, and closes the lid 10U. The multiple types of powder put in are contained within the ultra-low dew point air or inert gas inside the sealed powder holding device 10, that is, they do not react with moisture in the atmosphere. The multiple types of powder put in accumulate at the bottom of the powder holding device 10.

[0035] Figure 2 is a timing chart showing an example of the operation of each part of the powder dispersion device 100.

[0036] The operator connects the lower side of the powder holding device 10 to the connecting pipe 12 of the input device 1220, and when the operator operates the start button (not shown), the control device 55 controls each part at the timing shown in Figure 2.

[0037] (Mixing of multiple types of powders in the powder holding device 10) The control device 55 opens valves 28 and 30 and operates pump 26 to supply inert gas contained in inert gas storage tank 24 to powder holding device 10 via the opened valves 28 and 30 and inert gas supply nozzles 32 and 34.

[0038] The inert gas is supplied from the bottom of the powder holding device 10. As described above, the various types of powders that are put into the powder holding device 10 accumulate at the bottom of the powder holding device 10. When the inert gas is supplied from the bottom of the powder holding device 10 to the various types of powders held by the powder holding device 10, each powder is stirred up and mixed.

[0039] Furthermore, the mixing device 2434 is equipped with multiple (for example, two) inert gas supply nozzles 32 and 34, so that inert gas can be supplied to the multiple types of powders held by the powder holding device 10 from multiple locations.

[0040] Furthermore, as shown in the timing chart TC1, the control device 55 controls the inert gas supply nozzles 32 and 34 so that inert gas is intermittently supplied to the powder holding device 10 from time t0 to time tn.

[0041] The period T during which the inert gas is intermittently supplied to the powder holding device 10, from time t0 to time tn, is determined according to the various types of powder. This is because the time required for mixing differs depending on the particle size, specific gravity, or amount of powder input for each powder. In this embodiment, the inert gas is supplied for a time corresponding to the type of powder.

[0042] At time tn, since the multiple types of powders have been mixed with inert gas, the operator stops the supply of inert gas by operating a stop button (not shown) and manually opens the on / off shutter 10S. As a result, the mixed multiple types of powders reach the supply adjustment device 14 through the connecting pipe 16.

[0043] (Dispersion of multiple types of powders in a solvent) Incidentally, when the dispersion device 22 is operated, cavitation occurs in the solvent inside the dispersion device 22. As shown in graph G of Figure 2, the pressure inside the dispersion device 22 decreases from the time ts when operation starts, and it is expected that the pressure inside the dispersion device 22 will become negative after a predetermined time U has elapsed from the time ts when operation starts. Time U is calculated from the amount of solvent inside the dispersion device 22 and the mobility of the cavitation generating part (not shown) that generates cavitation. Therefore, as shown in timing chart TC2, in this embodiment, the control device 55 starts operating the dispersion device 22 at the time ts when operation starts, which is time U before time tn, so that the pressure inside the dispersion device 22 becomes negative at time tn. The reason for creating a negative pressure inside the dispersion device 22 is, as will be described later, that when the input shutter 18 is opened and multiple types of powder are introduced into the dispersion device 22 from the powder holding device 10, the negative pressure inside the dispersion device 22 draws in multiple types of powder along with an inert gas, and prevents the multiple types of powder from reacting with moisture in the atmosphere due to the air inside the dispersion device 22.

[0044] The above time U is the time when the pressure inside the dispersion device 22 becomes negative. However, due to environmental influences, the pressure inside the dispersion device 22 may not be negative at time tn. Therefore, in this embodiment, the control device 55 takes in the pressure inside the dispersion device 22 from the detection sensor 54 of the dispersion device 22 and determines whether the taken pressure is negative or not. If the control device 55 does not determine that the taken pressure is negative, it repeats the determination. When the control device 55 determines that the taken pressure is negative (see time tc in graph G), it introduces multiple types of powder into the solvent where cavitation is occurring. Specifically, as shown in the timing chart TC4, the control device 55 controls the motor 18M so that the input shutter 18 is opened at time tc when it is determined that the taken pressure is negative. Furthermore, as shown in the timing chart TC3, the control device 55 controls the motor 14M from time tc so that the rotational speed of the rotor of the supply adjustment device 14 becomes constant, and multiple types of powder are continuously introduced into the solvent through the open input shutter 18 in a constant amount. As a result, multiple types of powder are continuously introduced into the solvent where cavitation is occurring in a constant amount. The opening of the input shutter 18 is not limited to the motor; linear motion equipment such as an air cylinder or hydraulic cylinder may also be used.

[0045] Multiple types of powders are added in fixed amounts to a solvent where cavitation is occurring. At time tz, when all the powders have been added, the control device 55 controls motor 18M to close the input shutter 18 and motor 14M to stop the rotor from rotating. The dispersion of the multiple types of powders progresses in fixed amounts from time tz, when a predetermined time Z has elapsed from time tz, according to the multiple types of powders, until the dispersion of the slurry is complete at time ty.

[0046] As shown in the timing chart TC5, the control device 55 controls the introduction device 22I so that the fixing agent is introduced into a solvent in which multiple types of powders are uniformly dispersed for a predetermined time from time tx to time ty. That is, according to the control of the control device 55, the introduction device 22I introduces multiple types of powders into a solvent in which cavitation is occurring via the tank 22T and the circulation pump 22P, and after the multiple types of powders are dispersed in the solvent by the cavitation, it introduces the fixing agent into the solvent in which the multiple types of powders are dispersed.

[0047] The control device 55 stops the operation of the dispersion device 22 at time te, which is a predetermined time after time ty, when the fixing agent has finished being introduced into the solvent, and when the dispersion of the fixing agent is complete.

[0048] The slurry of battery materials is manufactured as described above.

[0049] [effect] In this embodiment, before adding multiple types of powders to a solvent where cavitation is occurring, the powder holding device 10 premixes multiple types of powders with different properties. Therefore, the time required to disperse multiple types of powders in the solvent can be shortened compared to the conventional technique of adding the same type of powder to the solvent and stirring. Furthermore, compared to the case where multiple types of powders with different properties are added to a solvent where cavitation is occurring without premixing, multiple types of powders can be dispersed in the solvent more quickly.

[0050] In this embodiment, the mixing device 2434 supplies gas to multiple types of powders with different properties held in the powder holding device 10, thereby enabling the dispersion of moisture from the atmosphere and the transported powders in the solvent under general environmental conditions.

[0051] Specifically, stirring is susceptible to the influence of particle weight and viscosity, which can easily lead to uneven mixing. However, in this embodiment, when mixing powders of different particle sizes and properties, the supply of gas lifts the particles, preventing uneven distribution of heavy and light particles and suppressing the occurrence of uneven mixing.

[0052] In the case of stirring, the powder particles may be damaged by collisions and friction with each other. However, in this embodiment, since mixing is performed by gas supply, the frequency of direct contact between powder particles is reduced, making them less susceptible to physical damage.

[0053] In the case of stirring, if too much shear force is applied, the powder is more likely to aggregate. However, in this embodiment, since the individual powder particles are dispersed by the gas flow, the aggregation of powder particles can be suppressed.

[0054] In this embodiment, since the time required for mixing differs depending on the particle size and mass of each powder, supplying gas for a time appropriate to the type of powder can suppress insufficient mixing and further optimize the mixing process.

[0055] In this embodiment, the inert gas supply nozzles 32 and 34 of the mixing device 2434 are attached to the lower part of the powder holding device 10, and the inert gas is supplied from the lower part of the powder holding device 10 by the inert gas supply nozzles 32 and 34. The multiple types of powders that have been put into the powder holding device 10 accumulate on the lower side of the powder holding device 10, so when the inert gas is introduced from the lower part of the powder holding device 10 into the multiple types of powders held by the powder holding device 10, each powder is stirred up, and the mixing of the multiple types of powders can be promoted.

[0056] Furthermore, the mixing device 2434 is equipped with multiple (for example, two) inert gas supply nozzles 32 and 34. Therefore, inert gas can be introduced into the multiple types of powders held by the powder holding device 10 from multiple locations. Thus, compared to the case where inert gas is supplied from one location, in this embodiment, firstly, the gas flow of the inert gas spreads more evenly throughout the powder, each powder is efficiently lifted, and more uniform mixing can be achieved. In other words, uneven mixing can be suppressed. Secondly, with gas supply from one location, the gas flow tends to concentrate in specific parts, and the powder may not diffuse sufficiently. However, in this embodiment, since inert gas is supplied from multiple locations, the inert gas flows simultaneously in each part, so the entire powder can be mixed efficiently in a short time.

[0057] Furthermore, the control device 55 controls the inert gas supply nozzles 32 and 34 so that inert gas is supplied intermittently to the powder holding device 10. Compared to the case where inert gas is supplied continuously, with intermittent gas supply, the powder settles while the supply of inert gas is stopped, and is lifted again when the supply resumes, making it easier to disperse more uniformly.

[0058] In this embodiment, each of the multiple types of powders is a powder whose properties change when exposed to air, and the gas supplied to mix the multiple types of powders is an inert gas that has been treated to be free of moisture. Therefore, it is possible to suppress changes in the properties of the powders.

[0059] In this embodiment, when the pressure of the powder holding device 10 detected by the pressure detection sensor 52 is a predetermined value less than or equal to the pressure resistance of the powder holding device 10, the release valve 42 is opened, the seal of the powder holding device 10 is released, and inert gas is released. Therefore, damage to the powder holding device 10 can be suppressed.

[0060] In this embodiment, the leaked inert gas is recovered as described above, and the recovered inert gas is supplied to the powder holding device 10. This allows the inert gas to be reused, preventing waste and suppressing adverse effects on the environment.

[0061] If the fixing agent is introduced before the powder is dispersed in the solvent, the powder will react excessively with the fixing agent, making aggregation and clumping more likely. However, in this embodiment, the fixing agent is introduced after the powder has been dispersed by cavitation, so that the fixing agent acts on each powder particle while it is uniformly dispersed in the solvent. As a result, the powder does not aggregate, and uniform fixing is possible throughout the solvent.

[0062] Furthermore, if the fixing agent is introduced before the powder is dispersed in the solvent, there is a risk of uneven fixing due to the large contact surface area between the powder particles. However, in this embodiment, the fixing agent is introduced after the powder has been sufficiently dispersed, so the fixing agent acts uniformly on each powder particle, improving the fixing effect.

[0063] Furthermore, if the fixing agent is introduced before the powder is dispersed in the solvent, fixing will proceed before the powder is sufficiently dispersed in the solvent, making it easier for the powder particles to aggregate. However, in this embodiment, the fixing agent is introduced after the powder has been sufficiently dispersed by cavitation, so that each powder particle is fixed in an isolated state, and aggregation can be suppressed.

[0064] In this embodiment, the control device 55 controls the motor 14M so that the rotation speed of the rotor of the supply adjustment device 14 remains constant, and multiple types of powder are continuously introduced into the solvent in a constant amount through the open input shutter 18. By adjusting the amount of powder introduced in this way, the powder can be more easily dispersed uniformly in the solvent. If too much powder is introduced at once, the powder may clump together and not disperse sufficiently in the solvent. However, in this embodiment, since the amount of powder introduced is adjusted, dispersion proceeds in a constant amount at a time, thus achieving uniform mixing. In addition, introducing a large amount of powder at once increases the risk of particles coming into contact with each other, causing aggregation and clumping. However, in this embodiment, since the amount of powder introduced is adjusted, excessive contact between powder particles can be avoided, and dispersion can be achieved efficiently while preventing aggregation.

[0065] [Differentiation] In the above embodiment, each of the multiple types of powders is a battery material whose properties change when exposed to air. However, the technology of this disclosure is not limited to this, and other powders that do not denature when exposed to air may also be used, such as graphite, silicon-based materials (silicon (Si), silicone (Silicone), silicon oxide (silica (SiO2))). When using silicone, it is known that when the particle size is on the nano-order, it becomes alkaline in water, so in this case, it is preferable to use carbon dioxide as the gas used for mixing.

[0066] Thus, this modified example can also be applied to the dispersion of powders that become alkalized in water.

[0067] The mixing apparatus 2434 in the above embodiment mixes by supplying gas to a plurality of types of powders held in the powder holding device 10. The technology of this disclosure is not limited thereto. For example, the plurality of types of powders may be mixed by rotating a stirring propeller (also called a stirring blade or agitator blade).

[0068] Because a stirring propeller directly and physically mixes the powder, it provides a stronger mixing force. In particular, even with powders that tend to agglomerate, the stirring propeller can eliminate agglomeration and mix them uniformly.

[0069] [Note] Based on the above disclosures, the following addendum is proposed.

[0070] (Note 1) A powder holding section that seals and holds multiple types of powders with different properties, A mixing unit for mixing the multiple types of powders that are held, A dispersion section that contains a solvent and generates cavitation in the solvent, An input unit for introducing the mixed plurality of powders into the solvent in which cavitation is occurring, A powder dispersion apparatus equipped with [a specific feature].

[0071] According to the invention described in Appendix 1, since the multiple types of powders with different properties are pre-mixed in the powder holding unit before being added to the solvent in which cavitation is occurring, the multiple types of powders can be dispersed in the solvent more quickly compared to the case where multiple types of powders with different properties are added to the solvent in which cavitation is occurring without pre-mixing.

[0072] (Note 2) The mixing unit mixes the powders by supplying gas to the plurality of types of powders. The powder dispersion apparatus described in Appendix 1.

[0073] According to the invention described in Appendix 2, since the gas is supplied to multiple types of powders with different properties for mixing, compared to stirring the multiple types of powders with different properties using a stirring unit, the gas flow spreads throughout the multiple types of powders, making it easier to mix them more uniformly.

[0074] (Note 3) The mixing unit supplies the gas for a time determined according to the plurality of types of powder. Powder dispersion apparatus as described in Appendix 2.

[0075] According to the invention described in Appendix 3, since the time required for mixing differs depending on the particle size and mass of each powder, supplying gas for a time appropriate to the type of powder can suppress insufficient mixing and further optimize the mixing process.

[0076] (Note 4) The mixing section is The gas is supplied from the lower part of the powder holding section. To supply intermittently, The powder is supplied from multiple locations in the powder holding section. Configured to be able to do at least one of the following: Powder dispersion apparatus as described in Appendix 2 or Appendix 3.

[0077] According to the invention described in Appendix 4, the mixing process can be optimized in that it can be mixed uniformly or in a short amount of time.

[0078] (Note 5) The aforementioned gas is a gas that has been treated to be free of moisture. A powder dispersion apparatus as described in any one of the items in Appendix 2 to Appendix 4.

[0079] According to the invention described in Appendix 5, changes in the properties of the powder can be suppressed.

[0080] (Note 6) The powder holding section is sealed. A pressure detection unit for detecting the pressure of the powder holding section, If the detected pressure is less than or equal to a predetermined value that is below the pressure resistance of the powder holding section, an opening is provided to release the seal of the powder holding section, It also has, Powder dispersion apparatus as described in Appendix 5.

[0081] According to the invention described in Appendix 6, it is possible to suppress the breakage of the powder holding part.

[0082] (Note 7) The system further includes a recovery and supply unit that recovers the gas that has leaked out when the seal of the powder holding unit is broken by the aforementioned opening, and supplies the recovered gas to the powder holding unit. Powder dispersion apparatus as described in Appendix 6.

[0083] According to the invention described in Appendix 7, gas can be reused, preventing waste and mitigating adverse environmental impacts.

[0084] (Note 8) After the plurality of types of powders are introduced into the solvent in which cavitation is occurring, and after the cavitation is dispersed in the solvent by the cavitation, the system further includes an introduction section for introducing a fixing agent into the solvent in which the plurality of types of powders are dispersed. A powder dispersion apparatus as described in any one of the appendices 1 to 7.

[0085] According to the invention described in Appendix 8, by introducing a fixing agent after the powder has been dispersed by cavitation, the fixing agent can be applied while each powder is uniformly dispersed in the solvent.

[0086] (Note 9) The input unit includes a rotating body, and by adjusting the rotational speed of the rotating body, the amount of the plurality of powders to be introduced into the solvent is adjusted. A powder dispersion apparatus as described in any one of the appendices 1 to 8.

[0087] According to the invention described in Appendix 9, the powder can be uniformly dispersed in the solvent by adjusting the amount of powder added. [Explanation of Symbols]

[0088] 10 Powder holding device 2434 Mixing equipment 22 Dispersion device 1220 Feeding device 52 Pressure detection sensor 42 Opening valve 3644 Recovery and supply device 22I introduction device

Claims

1. A powder holding section that seals and holds multiple types of powders with different properties, A mixing unit for mixing the multiple types of powders that are held, A dispersion section that contains a solvent and generates cavitation in the solvent, An input unit for introducing the mixed plurality of powders into the solvent in which cavitation is occurring, A powder dispersion apparatus equipped with [a specific feature].

2. The mixing unit mixes the powders by supplying gas to the plurality of types of powders. The powder dispersion apparatus according to claim 1.

3. The mixing unit supplies the gas for a time determined according to the plurality of types of powder. The powder dispersion apparatus according to claim 2.

4. The mixing section is The gas is supplied from the lower part of the powder holding section. To supply intermittently, The powder is supplied from multiple locations in the powder holding section. Configured to be able to do at least one of the following, The powder dispersion apparatus according to claim 2.

5. The aforementioned gas is a gas that has been treated to be free of moisture. The powder dispersion apparatus according to claim 2.

6. The powder holding section is sealed. A pressure detection unit for detecting the pressure of the powder holding section, If the detected pressure is less than or equal to a predetermined value that is below the pressure resistance of the powder holding section, an opening is provided to release the seal of the powder holding section, It also has, The powder dispersion apparatus according to claim 5.

7. The system further includes a recovery and supply unit that recovers the gas that has leaked out when the seal of the powder holding unit is broken by the aforementioned opening, and supplies the recovered gas to the powder holding unit. The powder dispersion apparatus according to claim 6.

8. After the plurality of types of powders are introduced into the solvent in which cavitation is occurring, and after the cavitation is dispersed in the solvent by the cavitation, the system further includes an introduction section for introducing a fixing agent into the solvent in which the plurality of types of powders are dispersed. The powder dispersion apparatus according to claim 1.

9. The input unit includes a rotating body, and by adjusting the rotational speed of the rotating body, the amount of the plurality of powders to be introduced into the solvent is adjusted. The powder dispersion apparatus according to claim 1.

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