Method for manufacturing a dispersion composition

Abstract

To provide a method for manufacturing a dispersion composition that prevents a decrease in the cooling efficiency of a plunger, enhances dispersibility, and improves productivity. [Solution] A method for producing a dispersed composition is provided, which uses a dispersion apparatus comprising a dispersion mechanism for dispersing a raw material composition, a supply mechanism equipped with a plunger section for supplying the raw material composition to the dispersion mechanism, and a cooling mechanism for cooling the plunger section using a cooling liquid medium, wherein the raw material composition comprises a non-aqueous dispersion medium and a dispersed phase, and the cooling liquid medium is a liquid medium having 0 to 50 particles of 10 μm or larger in a specific agglomeration test.

Description

Technical Field

[0001] The present invention relates to a method for producing a dispersion composition.

Background Art

[0002] As methods for dispersing a dispersoid in a non-aqueous dispersion medium, there are a stirrer, a ball mill disperser, a bead mill disperser, an ultrasonic disperser, a single-screw kneader, a multi-screw kneader, a roll mill disperser, a high-pressure homogenizer, and the like. From the viewpoint of dispersion efficiency, the bead mill disperser is widely used. The bead mill has the advantage that the dispersoid is finely dispersed by applying an impact to the dispersoid, but the original properties of the dispersoid may be reduced due to damage to the dispersoid by the impact. The high-pressure homogenizer can uniformly disperse the treatment liquid by a method of discharging the treatment liquid from a nozzle or a method of passing the treatment liquid through a homogenizing valve. Since the treatment liquid is supplied at a high pressure to increase the dispersion efficiency, the dispersoid can be finely dispersed by the shearing force and collision between the treatment liquids, the collision with the wall surface of the homogenizing valve, and the like.

[0003] The valve-type high-pressure homogenizer can increase the flow rate of the treatment liquid, and is suitable for mass production because it does not require a nozzle that causes clogging, and is used as a homogenizing device for aqueous systems such as dairy products and beverages. Since dairy products and the like have a small solid content and are aqueous systems, the action on the members of the dispersion device is small. For example, there is an advantage that the deterioration of the packing of the high-pressure pump is slow and the replacement period is long. Further, even if the treatment liquid leaks out due to deterioration of the packing of the high-pressure pump or the like, since it is an aqueous treatment liquid, it can be recovered and easily treated. Since the high-pressure pump is loaded with a high pressure and heat is generated, some have a cooling mechanism using cooling water. Even if the aqueous treatment liquid leaks from the high-pressure pump, there are few problems because it is recovered together with the cooling water.

[0004] In recent years, high-pressure homogenizers have also been used as dispersion devices for solvent-based systems such as inks, and are particularly used as dispersion devices for solvent-based systems containing carbon materials, including carbon nanotubes. The solvent-based processing liquids tend to react with the packings of high-pressure pumps, leading to packing deterioration, shortening the replacement interval, and potentially reducing work efficiency. Furthermore, packing deterioration can also increase the risk of solvent leakage from the high-pressure pump.

[0005] Patent Document 1 proposes a method for producing a pigment-containing polymer particle aqueous dispersion by removing the organic solvent from a mixture containing water and an organic solvent solution of a polymer, and then dispersing the desolvented product. This method improves workability by preventing the volatilization of the organic solvent during the disassembly and cleaning of the dispersion equipment, as well as preventing deterioration of the packing of the dispersion equipment.

[0006] Patent Document 2 proposes a method for dispersing carbon nanotubes in which a crude dispersion containing carbon nanotubes and a solvent is stored in a tank and sent to a disperser by a high-pressure pump. This method involves cooling the high-temperature carbon nanotube dispersion discharged from the disperser to prevent the generation of bubbles in the dispersion, and reducing the back pressure of the dispersion in multiple stages to prevent the generation of bubbles when atmospheric pressure is released, thereby improving the dispersibility of carbon nanotubes. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2001-247810 [Patent Document 2] International Publication No. 2015 / 015758 [Overview of the project] [Problems that the invention aims to solve]

[0008] When manufacturing a non-aqueous dispersion composition, if the cooling water used to cool the high-pressure pump mixes with the raw material composition leaking from the high-pressure pump, the non-aqueous dispersion medium will be mixed with the dispersed phase in the cooling water wastewater, making it difficult to reuse or dispose of the cooling water as water. When water is mixed into a system in which the dispersion stability of the dispersed phase is maintained in the non-aqueous dispersion medium, the stability of the system is disrupted, and the dispersed phase may aggregate, resulting in the formation of aggregates. Since the leaked liquid contains both the non-aqueous dispersion medium and the dispersed phase, an additional step is added to remove solids by filtration or other means in order to reuse the cooling water, but if aggregates have formed, there is a problem in removing the solids.

[0009] Such malfunctions can reduce the circulation efficiency for reusing the cooling water, leading to a decrease in the cooling efficiency of the high-pressure pump. This can cause the pump's components to deteriorate due to exposure to high temperatures. For example, sealing components such as packing in the high-pressure pump may deteriorate due to high temperatures, causing pressure loss in the pump. Packing deterioration can lead to decreased operating efficiency, shorter replacement intervals, and ultimately reduce productivity.

[0010] Patent Document 1 prevents deterioration of the packing of a high-pressure homogenizer by pre-removing the organic solvent contained in the aqueous dispersion of pigment-containing polymer particles. However, this does not resolve the problem of packing deterioration when the dispersion composition is a non-aqueous dispersion medium. Patent Document 2 supplies a crude dispersion to a high-pressure homogenizer using a high-pressure pump, but it only focuses on cooling the dispersion after it has been processed by the high-pressure homogenizer to prevent the generation of bubbles and improve dispersibility, and does not consider the decrease in productivity due to the high temperature of the high-pressure pump.

[0011] The pressurization mechanism of a high-pressure homogenizer applies pressure to the processing liquid in the cylinder using a plunger, supplying the high-pressure processing liquid to a dispersion section consisting of a nozzle or homogenization valve. Since frictional heat is generated at the sliding surface between the seal in the cylinder and the plunger, one method is to cool the plunger to prevent deterioration of the seal material. Furthermore, because the plunger moves back and forth within the cylinder, the processing liquid is prone to leakage as the plunger moves back and forth, and the above-mentioned problems can occur if the processing liquid is a non-aqueous dispersion medium.

[0012] One objective of the present invention is to prevent a decrease in the cooling efficiency of the plunger section, improve the dispersibility of the dispersion composition, and improve productivity. [Means for solving the problem]

[0013] As a result of the present inventors' diligent research aimed at solving the above problems, in the step of applying a cooling liquid medium to the plunger section, the cooling liquid medium is a liquid medium having 0 to 50 particles of 10 μm or larger in a predetermined agglutination test. In a method for producing a dispersion composition containing a non-aqueous dispersion medium, by selecting a liquid medium with high affinity to the raw material composition as the cooling liquid medium for cooling the plunger section, even if the raw material composition leaks from the cylinder section and comes into contact with the cooling liquid medium, the generation of aggregates due to the dispersed phase, dispersant, etc. can be suppressed. As a result, when the cooling liquid medium is reused and circulated, a decrease in cooling efficiency can be prevented, for example, the deterioration of sealing members such as packing can be prevented, the lifespan of the sealing members can be extended, and long-term operation can be made possible. In addition, the replacement period for sealing members can be extended, improving workability. Furthermore, a decrease in pressure loss due to the deterioration of sealing members can be suppressed, and the processing liquid can be supplied at high pressure from the high-pressure pump to the dispersion mechanism, improving the dispersibility of the dispersion composition.

[0014] In other words, the present invention includes the following embodiments. The embodiments of the present invention are not limited to the following. <1> A method for producing a dispersed composition, using a dispersion apparatus comprising a dispersion mechanism for dispersing a raw material composition, a supply mechanism for supplying the raw material composition to the dispersion mechanism and having a plunger section, and a cooling mechanism for cooling the plunger section using a cooling liquid medium, wherein the raw material composition comprises a non-aqueous dispersion medium and a dispersed phase, and the cooling liquid medium is a liquid medium having 0 to 50 particles of 10 μm or larger in the following agglomeration test. (Agglomeration test) A method for preparing a test dispersion by dispersing the same composition as the raw material composition using a bead mill or high-pressure homogenizer, and measuring the particle size with a grindometer (0-100 μm) to less than 10 μm; preparing a test sample by mixing the test dispersion and the cooling liquid medium in a mass ratio of 1:1 at 25°C; and confirming the number of particles of 10 μm or larger in the test sample with a grindometer (0-100 μm).

[0015] <2> The non-aqueous dispersion medium of the raw material composition and the cooling liquid medium contain the same liquid medium. <1> A method for producing the dispersion composition described above. <3> The leakage rate of the raw material composition from the supply mechanism represented by the following formula (1) is 0.2% or less per 100 hours of operation. <1> or <2> A method for producing the dispersion composition described above. Leakage rate (%) = (Amount of raw material composition leaking from the supply mechanism (L) / Amount of raw material composition supplied (L)) × 100 (1)

[0016] <4> A method for producing a dispersed composition, using a dispersion apparatus comprising a dispersion mechanism for dispersing a raw material composition, a supply mechanism for supplying the raw material composition to the dispersion mechanism and having a plunger section, and a cooling mechanism for cooling the plunger section using a cooling liquid medium, wherein the raw material composition comprises a dispersed phase, a non-aqueous dispersion medium, and a dispersant, and the cooling liquid medium is a liquid medium in which no solid precipitates are formed at 25°C when a solution of the non-aqueous dispersion medium containing 5% by mass of the dispersant is mixed with the cooling liquid medium in a mass ratio of 1:1.

[0017] <5>A method for manufacturing a dispersion composition using a dispersion device comprising a dispersion mechanism for dispersing a raw material composition, a supply mechanism provided with a plunger part for supplying the raw material composition to the dispersion mechanism, and a cooling mechanism for cooling the plunger part using a cooling liquid medium, wherein the raw material composition contains a dispersoid, a non-aqueous dispersion medium, and a dispersant, and at 25°C, the cooling liquid medium is a liquid medium that dissolves 0.1% by mass or more of the dispersant contained in the raw material composition.

Advantages of the Invention

[0018] According to one embodiment of the present invention, it is possible to prevent a decrease in the cooling efficiency of the plunger part, enhance the dispersibility of the dispersion composition, and improve productivity.

Brief Description of the Drawings

[0019] [Figure 1] It is a schematic diagram showing an example of a dispersion device. [Figure 2] It is a cross-sectional view schematically showing a high-pressure pump and a cooling mechanism of an example of a dispersion device. [Figure 3] It is a cross-sectional view schematically showing a homogenization valve of a dispersion part of an example of a dispersion device.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, a method for manufacturing a dispersion composition according to an embodiment of the present invention will be described in detail. The present invention is not limited to the following embodiments, and embodiments implemented within a range not changing the gist of the present invention are also included.

[0021] <Dispersion Device> The following describes a method for producing a dispersion composition containing a dispersed phase and a non-aqueous dispersion medium using a dispersion apparatus. The non-aqueous dispersion medium may further contain a dispersant. The dispersion composition can be produced using a dispersion apparatus comprising a dispersion mechanism for dispersing a raw material composition, a supply mechanism equipped with a plunger section for supplying the raw material composition to the dispersion mechanism, and a cooling mechanism for cooling the plunger section using a cooling liquid medium. The raw material composition is a composition containing a mixture of the raw materials of the dispersion composition. The raw material composition may be a composition in a mixed state, or a composition in a roughly dispersed state after mixing. An example of such a dispersion apparatus is a high-pressure homogenizer. In a high-pressure homogenizer, the raw material composition can be supplied at high pressure from a high-pressure pump to the dispersion section by the reciprocating movement of a plunger, and the raw material composition can be dispersed in the dispersion section. In one example of a dispersion section, the raw material composition can be sprayed at high pressure from a micro-pole at the tip of a nozzle, and the dispersed phase can be dispersed in the non-aqueous dispersion medium by collisions and shear forces between the raw material compositions. In another example of a dispersion unit, the raw material composition is supplied to a homogenization valve at high pressure, and the dispersion phase can be dispersed in a non-aqueous dispersion medium by impacting the raw material composition against the wall of the homogenization valve. The method of performing dispersion processing using a homogenization valve allows for a high flow rate of the raw material composition, avoids problems such as nozzle clogging, and is suitable for mass production. The pressure of the raw material composition supplied to the dispersion unit is preferably 10 to 150 MPa. If the dispersion unit is of the nozzle type, the pressure of the raw material composition supplied to the dispersion unit is preferably in the normal range of 60 to 150 MPa, more preferably 80 to 150 MPa, and even more preferably 100 to 150 MPa. If the disperser is of the valve type, the pressure of the raw material composition supplied to the disperser is preferably in the normal range of 10 to 150 MPa, more preferably 40 to 150 MPa, and even more preferably 80 to 150 MPa. Furthermore, from the viewpoint of dispersion efficiency, a valve-type homogenizer and a nozzle-type homogenizer may be used in combination for dispersion, and from the viewpoint of adjusting the dispersion state, a bead mill or high-shear mixer other than a high-pressure homogenizer may also be used in combination for dispersion.

[0022] Figure 1 shows a schematic diagram of an example of a dispersion device. The dispersion device 100 comprises a plunger 10, a high-pressure pump 20, a dispersion unit 30, and a cooling mechanism 40. The raw material composition tank 50 is a container that holds the raw material composition supplied to the high-pressure pump 20. The high-pressure pump 20 comprises a supply port 22 through which the raw material composition is supplied from the raw material composition tank 50, and a discharge port 23 through which the raw material composition is discharged to the dispersion unit 30. The high-pressure pump 20 comprises a cylinder section 21 that supports the plunger 10 so that it can reciprocate in the axial direction. The cylinder section 21 is preferably provided with a sealing mechanism to prevent the raw material composition and pressure from leaking out of the high-pressure pump 20. An example of a sealing mechanism is a seal member that is arranged around the entire circumference in the circumferential direction on the inner circumference of the cylinder section 21. An example of a seal member is a gland packing, which is composed of one or a combination of organic fibers such as aramid fibers, PTFE fibers, and carbonized fibers, inorganic fibers such as carbon fibers and metal fibers, and natural fibers such as ramie fibers.

[0023] One end of the plunger 10 is inserted into the high-pressure pump 20, and the other end extends outside the high-pressure pump 20 and is supported by the cylinder portion 21. Preferably, the sliding surface between the plunger 10 and the cylinder portion 21 is slidably sealed to prevent leakage of the raw material composition from the high-pressure pump 20, and further preferably, no pressure loss occurs due to air leakage from the high-pressure pump 20 to the outside. As the plunger 10 reciprocates in the axial direction, the volume of the pressure chamber of the high-pressure pump 20 changes. When the plunger 10 is withdrawn from the high-pressure pump 20 and the volume of the pressure chamber increases, the raw material composition is drawn in from the supply port 22 of the high-pressure pump 20. When the plunger 10 is pushed out of the high-pressure pump 20 and the volume of the pressure chamber decreases, the raw material composition is discharged from the discharge port 23 of the high-pressure pump 20. Valves may be provided at the supply port 22 and the discharge port 23 of the high-pressure pump 20 to prevent backflow of the raw material composition.

[0024] The raw material composition discharged from the high-pressure pump 20 is supplied to the dispersion unit 30 at high pressure. The dispersion unit 30 may be a nozzle type or a valve type. Since a large amount of raw material composition can be supplied to the dispersion unit 30 at high pressure using the plunger 10, the dispersion unit 30 is preferably a valve type, and specifically a homogenization valve is preferred. After the dispersion treatment, a dispersed composition is obtained in which the dispersed phase is dispersed in a non-aqueous dispersion medium. Although not shown, the dispersed composition can be recovered into a dispersed composition tank by piping from the discharge port of the dispersion unit 30.

[0025] The cooling mechanism 40 comprises a cooling liquid medium tank 41 and a cooling unit 42. The cooling mechanism 40 includes a pipe 40a for supplying the liquid medium from the cooling liquid medium tank 41 to the cooling unit 42, and a pipe 40b for discharging the liquid medium from the cooling unit 42. The pipe 40b is connected to a recovery container 43, allowing the used liquid medium to be recovered in the recovery container 43. In another example, the liquid medium recovered in the recovery container 43 may be filtered, and the liquid medium from which solids have been removed may be recirculated to the cooling liquid medium tank 41 through pipe 40c for reuse. The cooling unit 42 is a component that cools the plunger 10 extending to the outside from the high-pressure pump 20. The cooling unit 42 is, for example, a component that surrounds the outer circumference of the plunger 10 extending to the outside from the high-pressure pump 20 and liquid-tightly covers the opening of the cylinder portion 21. When the cooling unit 42 is filled with a cooling liquid medium, the cooling liquid medium comes into direct contact with the plunger 10 and the opening of the cylinder section 21, and cooling is performed. The outer surface of the plunger 10 is cooled, and as the plunger 10 continues to move back and forth, the cooled outer surface portion of the plunger 10 enters the inside of the cylinder section 21 of the high-pressure pump 20, and the inside of the cylinder section 21 can also be cooled. This allows sealing members such as gland packing placed on the inner surface of the cylinder section 21 to be cooled. The cooling unit 42 is supplied with a cooling liquid medium from the cooling liquid medium tank 41 through piping 40a, and the cooling liquid medium is discharged from the cooling unit 42 to the recovery container 43 through piping 40b. Although not shown, the cooling liquid medium discharged from the cooling unit 42 may be collected by simply dropping it into the recovery container 43 or a tray, etc., without providing piping 40b from the cooling unit 42 to the recovery container 43. Alternatively, instead of providing a recovery container 43, the cooling liquid medium discharged from the cooling unit 42 may be returned directly to the cooling liquid medium tank 41.

[0026] Another example of a cooling mechanism, although not shown, is to provide a supply port for a cooling liquid medium at the top of a plunger extending from a high-pressure pump, and perform cooling by directly dripping the cooling liquid medium onto the plunger. In this case, the cooling liquid medium that falls after being dripped onto the plunger can be collected in a collection container or tray.

[0027] As yet another example of a cooling mechanism, although not shown, cooling piping for a cooling liquid medium may be arranged inside the cylinder section. When the cooling liquid medium is supplied to this cooling piping, the inside of the cylinder section is cooled by the cooling piping, thereby cooling the sealing member arranged on the inner circumferential surface of the cylinder section and the plunger that slides against it. The cooling liquid medium supplied to the cooling piping inside the cylinder section is discharged from the opening of the cylinder section. For example, the cooling liquid medium discharged from the cooling piping may be discharged to the cooling section 42 described above, or it may be collected in a recovery container 43 by a separate pipe, or it may be collected by simply dropping it into the recovery container 43 or a tray. In any of the above cooling mechanism methods, since the cooling liquid medium is in direct contact with the plunger, if the raw material composition leaks from the high-pressure pump through the cylinder section, the raw material composition may come into contact with the cooling liquid medium.

[0028] A specific example of the dispersion apparatus will be explained using Figures 2 and 3. Components common to Figure 1 are denoted by the same reference numerals, and parts not specifically described are as described in Figure 1. Figure 2 is a schematic cross-sectional view showing the high-pressure pump 20 and cooling mechanism 40 of the dispersion apparatus. In Figure 2, the high-pressure pump 20 includes a cylinder section 21, a gland packing 24 disposed on the inner circumferential surface of the cylinder section 21, and ball valves 22' and 23' disposed at the supply port 22 and discharge port 23, respectively. The cooling mechanism 40 includes a cooling liquid medium tank 41, a cooling section 42, a pump 44, and a heat exchanger 45. The plunger 10 is reciprocating and is supported in the cylinder section 21 so as to be liquid-tight and slidable by the gland packing 24. The reciprocating movement of the plunger 10 supplies and discharges the raw material composition to the high-pressure pump 20 in the direction of the arrow in the figure. In the cooling mechanism 40, the cooling liquid medium is pumped from the cooling liquid medium tank 41 by a pump 44 in the direction of the arrow in the figure and filled into the cooling unit 42. Then, the cooled and heated cooling liquid medium is discharged from the top of the cooling unit 42 and sent back to the cooling liquid medium tank 41 for circulation. A heat exchanger 45 is provided between the piping from the cooling unit 42 to the cooling liquid medium tank 41 to cool the heated cooling liquid medium before circulation.

[0029] Figure 3 is a schematic cross-sectional view showing the homogenization valve of the dispersion section 30. In Figure 3, the homogenization valve of the dispersion section 30 comprises a valve seat 31, an impact ring 32, and a homovalve 33. The raw material composition supplied from the high-pressure pump 20 is supplied to the homogenization valve at high pressure in the direction of the arrow in the figure, subjected to fine dispersion treatment, and then discharged from the discharge port, as shown in the appendix.

[0030] Examples of valve-type high-pressure homogenizers, which are dispersion devices, include the "HC3 series" from Sanmaru Machinery Co., Ltd., the "HV-H series" from Izumi Food Machinery Co., Ltd., and the "R-Model" from SPX Flow Co., Ltd. Other examples of dispersion devices include nozzle-type high-pressure homogenizers. Examples of nozzle-type high-pressure homogenizers include the "Genus PY" from Genus Co., Ltd., the "Starburst" from Sugino Machine Co., Ltd., and the "Nanomizer" from Nanomizer Co., Ltd., but are not limited to these. A nozzle-type high-pressure homogenizer consists of a pump and one or more nozzles, and there are various nozzle shapes for dispersion processing. For example, there are types that collide raw materials with each other under high pressure, types that collide high-pressure raw materials with ceramic balls or pass them through slits and process them with the resulting shear force, and types that utilize cavitation by a jet of high-pressure raw materials, but are not limited to these.

[0031] <Agglomeration Test> In the manufacture of dispersion compositions containing a non-aqueous dispersion medium, if the cooling liquid medium is water and leakage of the raw material composition occurs, the stability of the system of the dispersed phase and the non-aqueous dispersion medium of the raw material composition may be disrupted by miscibility with water, causing the dispersed phase to aggregate and form aggregates. Furthermore, if the raw material composition contains a dispersant along with the dispersed phase, the stability of the system is more easily disrupted by water, making the formation of aggregates even more likely. These aggregates accumulate and clog the pipes and tanks used for discharging the cooling liquid medium, reducing the cooling efficiency of the plunger, exposing the plunger and its surrounding components to high temperatures, which can lead to deterioration of sealing components, particularly gland packing. Deterioration of the sealing components causes pressure loss, reducing the pressure load on the plunger, lowering the pressure of the raw material composition supplied to the dispersion section, and potentially reducing dispersibility. In addition, the replacement of sealing components requires stopping the dispersion equipment and discharging the raw material composition, which increases the work time and reduces productivity. Gland packing, in particular, is expensive, so frequent replacement leads to a decrease in production efficiency.

[0032] Therefore, the cooling liquid medium is preferably a liquid medium in which the number of particles 10 μm or larger is 0 to 50 in the following agglomeration test. (Agglomeration test) A method for preparing a test dispersion by dispersing the same composition as the raw material composition using a bead mill or high-pressure homogenizer, and measuring the particle size with a grindometer (0-100 μm) to less than 10 μm; preparing a test sample by mixing the test dispersion and the cooling liquid medium in a mass ratio of 1:1 at 25°C; and confirming the number of particles of 10 μm or larger in the test sample with a grindometer (0-100 μm).

[0033] In the agglutination test, the cooling liquid medium preferably contains 50 or fewer particles larger than 10 μm, more preferably 30 or fewer, even more preferably 10 or fewer, and even more preferably 3 or fewer. More preferably, in the agglutination test, the cooling liquid medium contains 0 or fewer particles larger than 10 μm, i.e., none are observed. By satisfying these conditions, even if the raw material composition leaks from the supply mechanism during the operation of the dispersion device and comes into contact with the cooling liquid medium, the generation of aggregates in the cooling liquid medium discharge piping, recovery container, etc., can be prevented.

[0034] The test dispersion is prepared by dispersing the same composition as the raw material composition and then using a grindometer (0-100 μm) to disperse until the particle size is less than 10 μm. The dispersion conditions vary depending on the type of raw material composition, but the goal is to disperse the raw material composition until the particle size is less than 10 μm as measured by the grindometer. For example, raw material compositions with low cohesiveness can be prepared by coarse dispersion using a bead mill, while raw material compositions with high cohesiveness can be finely dispersed using a high-pressure homogenizer. A grindometer with a groove depth of 0 μm to 100 μm and a scale interval of 10 μm is used to measure the particle size of the test dispersion.

[0035] The test sample is prepared by mixing the test sample and the cooling liquid medium in a 1:1 mass ratio at 25°C. The mixing method should be such that the test sample and the cooling liquid medium are thoroughly mixed, and mixing using a stirring device is recommended. A rotation-and-revolution type stirring device is recommended because it can remove bubbles generated during mixing. For example, stirring at 2000 rpm for 30 seconds using a rotation-and-revolution type stirring device is recommended. The number of particles 10 μm or larger in the obtained test sample is confirmed at 25°C using a grindometer (0-100 μm). A grindometer with a groove depth of 0 μm to 100 μm and a scale interval of 10 μm is used to confirm the number of particles 10 μm or larger in the test sample. The number of particles 10 μm or larger is measured using a grindometer within 60 seconds after the preparation of the test sample. The agglomeration test is performed under conditions of 25°C and 1 atmosphere.

[0036] The cooling fluid medium may be a single-component liquid or a combination of two or more liquids. In the case of a cooling fluid medium that is a combination of two or more liquids, the cooling fluid medium used in the coagulation test shall be a mixture of two or more liquids in the same mass ratio as the cooling fluid medium used in the dispersion device.

[0037] The type of cooling liquid medium is not particularly limited as long as it satisfies the above-mentioned coagulation test, but a non-aqueous liquid medium is preferred, and an organic solvent is more preferred. Specifically, it can be selected and used from the organic solvents for raw material compositions described below. The cooling liquid medium is preferably a liquid medium that does not have water as its main component, and specifically, it is preferable that the proportion of water is less than 50% by mass. The cooling liquid medium is more preferably 10% by mass or less, even more preferably 1% by mass or less, and even more preferably substantially water-free. By selecting a non-aqueous liquid medium with high affinity to the raw material composition as the cooling liquid medium for cooling the plunger section, instead of water which has been widely used in the past, it is possible to suppress the generation of coagulations caused by dispersed phases, dispersants, etc., even if the raw material composition leaks from the cylinder section and comes into contact with the cooling liquid medium.

[0038] The cooling liquid medium only needs to satisfy the above-mentioned coagulation test, but it is preferable that it satisfies the coagulation test and also meets the following conditions. It is preferable that the cooling liquid medium is the same as the non-aqueous dispersion medium of the raw material composition. For example, if the raw material composition contains a single-component non-aqueous dispersion medium, it is preferable to use this non-aqueous dispersion medium as the cooling liquid medium. If the raw material composition contains multiple non-aqueous dispersion mediums, the cooling liquid medium may be a single component from among the multiple non-aqueous media of the raw material composition, a combination of two or more components, or a combination of all components. If all components are used, the blending ratio of each component may be the same as or different from that of the non-aqueous dispersion medium of the raw material composition. Preferably, if the raw material composition contains multiple non-aqueous dispersion mediums, the cooling liquid medium is a liquid medium containing the multiple non-aqueous dispersion mediums of the raw material composition in the same blending ratio.

[0039] In one embodiment of the method, it is preferable that the leakage rate of the raw material composition from the supply mechanism represented by the following formula (1) is 0.2% or less per 100 hours of operation. Leakage rate (%) = (Amount of raw material composition leaking from the supply mechanism (L) / Amount of raw material composition supplied (L)) × 100 (1)

[0040] In equation (1), the amount of raw material composition leaking from the supply mechanism is the amount of raw material composition that leaked from the supply mechanism to the cooling mechanism during 100 hours of operation, and the amount of raw material composition supplied is the total amount discharged from the dispersion section during 100 hours of operation. The amount of raw material composition leaking from the supply mechanism is determined according to the following procedure. (1) When replacing the gland packing, the cooling fluid medium is also replaced. Let the amount of cooling fluid medium at this time be X(L). (2) Let Y (L) be the amount of liquid recovered in the cooling fluid tank when the total operating time reaches 100 hours. The amount of leakage of the raw material composition from the supply mechanism is calculated using the following formula. Leakage amount of raw material composition from the supply mechanism (L) = Y(L) - X(L)

[0041] From the viewpoint of production efficiency of dispersed compositions using a dispersion device, it is preferable that the gland packing of the dispersion device be replaced at a frequency of once per month or less. A lifespan of several hundred hours or more is desired for the gland packing during the operation time of the dispersion device, and the amount of raw material composition leakage from the supply mechanism per 100 hours of operation, which is the initial to mid-stage of the replacement interval, is an important indicator for estimating the lifespan of the gland packing. If the onset of deterioration of the sealing member is not observed during 100 hours of operation, it is possible to predict that leakage of the raw material composition from the supply mechanism will not occur in subsequent operation. Therefore, if the leakage rate per 100 hours of operation is 0.2% or less, it can be confirmed that the cooling of the plunger section is being performed efficiently, and it can be predicted that deterioration of the gland packing will be further prevented in subsequent operation.

[0042] The leakage rate represented by formula (1) is preferably 0.2% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. If deterioration of the sealing member is prevented and the airtightness of the sliding surface between the cylinder and plunger of the high-pressure pump is further ensured, it is preferable that the leakage rate represented by formula (1) be close to 0%.

[0043] <Raw material composition> The raw material composition supplied to the dispersion device is not particularly limited as long as it comprises a dispersed phase and a non-aqueous dispersion medium. The raw material composition may further contain a dispersant to obtain dispersion stability of the dispersed phase. The raw material composition may optionally contain optional components such as resin emulsions, surfactants, binder resins, wetting agents, wetting penetrating agents, and leveling agents.

[0044] The dispersed phase may be inorganic particles, organic particles, inorganic-organic composite particles, or a combination thereof, and is preferably particles that can be dispersed in a non-aqueous dispersion medium, and preferably particles that are insoluble in a non-aqueous dispersion medium. Examples of inorganic particles include carbon materials, ceramics, and metals. Examples of carbon materials include carbon black, carbon nanotubes, fullerenes, graphene, multilayer graphene, and graphite. Examples of carbon black include acetylene black, furnace black, hollow carbon black, and Ketjen black. These carbon materials may be neutral, acidic, or basic, and may be oxidized or graphitized. Examples of ceramics include metal oxides, carbonates, nitrides, phosphates, and carbides, such as calcium oxide, calcium carbonate, magnesium oxide, magnesium carbonate, magnesium phosphate, aluminum oxide, aluminum nitride, aluminum phosphate, boron nitride, silicon oxide, silicon nitride, silicon carbide, zirconium oxide, titanium oxide, kaolin clay, and indium tin oxide (ITO). Examples of metals include zinc, lead, titanium, cadmium, iron, copper, cobalt, and alloys thereof.

[0045] As organic particles, resin particles are preferred, and examples include polystyrene, polyurethane, polyester, polyamide, vinyl polymers, acrylic polymers, and composite polymers thereof; cellulose, pulp fibers, and the like.

[0046] Inorganic or organic pigments may be used as the dispersed phase. Examples of organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dicutopyrrolopyrrole, and isoindoline pigments. More specifically, examples include carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, chromophthal yellow, chromophthal red, phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, diketopyrrolopyrrole red, aniline black, and daylight fluorescent pigments. Furthermore, examples of organic pigments include CI Pigment Black, CI Pigment Blue, CI Pigment Green, CI Pigment Red, CI Pigment Violet, CI Pigment Yellow, CI Pigment Orange, and CI Pigment Brown, which are organic compounds or organometallic complexes listed in the Color Index International (CI).

[0047] Examples of inorganic pigments include white pigments such as titanium dioxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, and silica; and pigments other than white, such as aluminum powder, mica, bronze powder, chrome vermilion, lead yellow, cadmium yellow, cadmium red, aluminum hydroxide, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, iron black, titanium dioxide, and zinc oxide.

[0048] The dispersed phase described above may be surface-treated. The dispersed phase may be used alone or in combination of two or more types. The content of the dispersed phase in the raw material composition is not particularly limited and should be appropriately adjusted according to the non-aqueous dispersion medium and the material of the dispersed phase, within a range in which the dispersed phase can be dispersed in the non-aqueous dispersion medium after dispersion treatment.

[0049] As the non-aqueous dispersion medium, any solvent capable of dispersing the dispersed phase may be used, depending on the type of dispersed phase, and organic solvents are preferred. The organic solvent may be either a non-polar solvent or a polar solvent, and these may be used in combination within the range of miscibility. Examples of non-polar solvents include aliphatic hydrocarbon solvents such as hexane, cyclohexane, and paraffin, aromatic hydrocarbon solvents such as benzene, toluene, and xylene, and other petroleum-based hydrocarbon solvents. Examples of polar solvents include ester solvents, ether solvents, alcohol solvents, ketone solvents, amide solvents, heterocyclic solvents, sulfoxide solvents, sulfone solvents, and carbonate solvents.

[0050] More specifically, non-aqueous dispersion media can include amides (N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylcaprolactam, etc.), heterocyclics (cyclohexylpyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, etc.), sulfoxides (dimethyl sulfoxide, etc.), sulfones (hexamethylphosphorotriamide, sulfolane, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), carbonates (diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, fluoroethylene carbonate, propylene carbonate, ethylene carbonate), and others such as tetrahydrofuran and acetonitrile.

[0051] Furthermore, examples of non-aqueous dispersion media include formic acid, acetic acid, methanol, ethanol, propanol, methyl acetate, ethyl acetate, diethyl ether, and α-terpineol. The above-mentioned non-aqueous dispersion media may be used individually or in combination of two or more.

[0052] The dispersant can be either a resin-type dispersant or a surfactant, but a suitable type of dispersant can be used in a suitable amount depending on the properties required for the dispersion of the dispersed phase.

[0053] As resin-type dispersants, (meth)acrylic polymers, polymers derived from ethylenically unsaturated hydrocarbons, cellulose derivatives, copolymers thereof, etc., can be used. Examples of polymers derived from ethylenically unsaturated hydrocarbons include polyvinyl alcohol resins, polyvinylpyrrolidone resins, polyacrylonitrile resins, and nitrile rubbers. Examples of polyvinyl alcohol resins include polyvinyl alcohol, modified polyvinyl alcohol having functional groups other than hydroxyl groups (e.g., acetyl groups, sulfo groups, carboxyl groups, carbonyl groups, amino groups), polyvinyl alcohol modified with various salts, other anionically or cationically modified polyvinyl alcohol, and polyvinyl acetals (polyvinyl acetal, polyvinyl butyral, etc.) modified with aldehydes (acetal modification or butyral modification, etc.). The polyacrylonitrile resin may be a homopolymer of polyacrylonitrile, a copolymer of polyacrylonitrile, or a modified version thereof. Preferably, the polyacrylonitrile resin has at least one selected from the group consisting of active hydrogen groups such as hydroxyl groups, carboxyl groups, primary amino groups, secondary amino groups, and mercapto groups, basic groups, alkyl groups introduced from (meth)acrylate or α-olefins, etc. For example, the acrylonitrile copolymer described in Japanese Patent Application Publication No. 2020-163362 can be used. Examples of nitrile rubbers include acrylonitrile butadiene rubber and hydrogenated acrylonitrile butadiene rubber. Examples of cellulose derivatives include cellulose acetate, cellulose acetate butyrate, cellulose butyrate, cyanoethylcellulose, ethyl hydroxyethylcellulose, nitrocellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, etc., or copolymers thereof. Furthermore, dispersants described in International Publication No. 2008 / 108360, Japanese Patent Publication No. 2018-192379, Japanese Patent Publication No. 2019-087304, Japanese Patent No. 6524479, and Japanese Patent Publication No. 2009-026744 may be used, but are not limited to these.Particularly preferred are methylcellulose, ethylcellulose, polyvinyl alcohol, polyvinyl butyral, polyvinylpyrrolidone, homopolymers of polyacrylonitrile, copolymers of polyacrylonitrile, and hydrogenated acrylonitrile butadiene rubber. Polymers in which other substituents have been introduced into some of these polymers, or modified polymers, may also be used.

[0054] The surfactant may be any of anionic, cationic, amphoteric, or nonionic surfactants. The dispersant is preferably 5 to 300 parts by mass, more preferably 10 to 200 parts by mass, and even more preferably 15 to 100 parts by mass, per 100 parts by mass of the dispersed phase.

[0055] The content of the dispersed phase relative to the total amount of the raw material composition varies depending on the specific gravity of the dispersed phase, but is preferably 0.1 to 80% by mass, more preferably 0.5 to 60% by mass, and even more preferably 0.7 to 50% by mass. The solid content of the raw material composition is preferably 0.5 to 80% by mass, more preferably 0.7 to 60% by mass, and even more preferably 1 to 50% by mass.

[0056] <Raw material composition containing carbon nanotubes> A dispersion apparatus according to one embodiment is suitable for applications that require dispersion while maintaining the shape of particles, as it can disperse particles by high-pressure treatment without applying mechanical impact to the particles. Furthermore, it is suitable for applications that improve dispersibility by defibrating lumpy materials such as fibrous particles. For example, it can be suitably used in a method for producing carbon nanotube dispersions. Hereinafter, carbon nanotubes will also be referred to as CNTs.

[0057] In a raw material composition containing carbon nanotubes, the non-aqueous dispersion medium can be any of the non-aqueous dispersion mediums described above. In a raw material composition containing carbon nanotubes, the non-aqueous dispersion medium preferably contains an aprotic solvent and a non-polar solvent, more preferably contains an aprotic solvent, and even more preferably contains an aprotic polar solvent. Aprotic polar solvents can better prevent the aggregation of carbon nanotubes and also have excellent solubility for resin-type dispersants suitable for dispersing carbon nanotubes. In particular, it is preferable to include an amide solvent, and more preferably to include at least one selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and 1-n-octyl-2-pyrrolidone.

[0058] In the raw material composition, carbon nanotubes in their pre-dispersion state preferably possess the following properties. CNTs have a cylindrical shape formed by winding planar graphite, and include single-walled CNTs and multi-walled CNTs, which may be mixed together. Single-walled CNTs have a structure in which one layer of graphite is wound. Multi-walled CNTs have a structure in which two or more layers of graphite are wound. Furthermore, the sidewalls of CNTs do not have to be of a graphite structure. For example, CNTs having sidewalls with an amorphous structure are also considered CNTs in this specification.

[0059] The shape of the CNT is not limited. Examples of such shapes include needle-shaped, cylindrical tube-shaped, fishbone-shaped (fishbone or cup-stacked type), playing card-shaped (platelet), and coil-shaped. Among these, the shape of the CNT is preferably needle-shaped or cylindrical tube-shaped. The CNT may be a single shape or a combination of two or more shapes.

[0060] Examples of CNT forms include graphite whiskers, filamentous carbon, graphite fibers, ultrafine carbon tubes, carbon tubes, carbon fibrils, carbon microtubes, and carbon nanofibers. Carbon nanotubes may exist in any single form or in combination of two or more of these forms.

[0061] The average outer diameter of the CNTs is preferably 1 nm or more, more preferably 1.2 nm or more. It is also preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 15 nm or less. The average outer diameter of the CNTs can be calculated by first observing and imaging the CNTs using a transmission electron microscope, selecting 300 arbitrary CNTs from the observation images, measuring the outer diameter of each, and averaging them.

[0062] The average fiber length of the CNTs is preferably 0.5 μm or more, more preferably 0.8 μm or more, and even more preferably 1.0 μm or more. It is also preferably 20 μm or less, and more preferably 10 μm or less. The average fiber length of the CNTs can be calculated by first observing and imaging the CNTs using a scanning electron microscope, selecting 300 arbitrary CNTs from the observation images, measuring the fiber length of each, and averaging them.

[0063] The aspect ratio of a carbon nanotube (CNT) is obtained by dividing its fiber length by its outer diameter. A typical aspect ratio can be determined using the average fiber length and average outer diameter. Conductive materials with higher aspect ratios can achieve higher conductivity when electrodes are formed from them. The aspect ratio of a CNT is preferably 30 or higher, more preferably 50 or higher, and even more preferably 80 or higher. It is also preferably 100,000 or less, more preferably 30,000 or less, and even more preferably 10,000 or less.

[0064] The specific surface area of ​​CNT is 100m². 2 It is preferable that it be 150m or more / g. 2 It is more preferable that it be 200m or more per gram. 2 It is even more preferable that it be 1200m or more. 2 It is preferable that it be less than or equal to / g, and 1000m 2 It is more preferable that the value be less than or equal to / g. The specific surface area of ​​CNTs is calculated by the BET method using nitrogen adsorption measurement.

[0065] The carbon nanotubes may be surface-treated carbon nanotubes. The carbon nanotubes may also be carbon nanotube derivatives to which functional groups, such as carboxyl groups, have been added. Furthermore, carbon nanotubes containing organic compounds, metal atoms, or substances such as fullerenes can also be used.

[0066] The raw material composition containing carbon nanotubes may contain a dispersant, and the above-mentioned dispersants can be used. To further enhance the dispersion stability of carbon nanotubes in a non-aqueous dispersion medium, it is preferable to use a resin-type dispersant. Methylcellulose, ethylcellulose, polyvinyl alcohol, polyvinyl butyral, polyvinylpyrrolidone, polyacrylonitrile homopolymers, polyacrylonitrile copolymers, and hydrogenated acrylonitrile butadiene rubber are particularly preferred. The raw material composition containing carbon nanotubes may further contain optional components such as the above-mentioned binder resins.

[0067] The carbon nanotube content is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% by mass, and even more preferably 0.7 to 10% by mass, relative to the total amount of the raw material composition. The dispersant is preferably 5.0 to 300 parts by mass relative to the carbon nanotubes. The raw material composition containing carbon nanotubes has a solid content of preferably 0.5 to 50% by mass, more preferably 0.7 to 30% by mass, and even more preferably 1 to 20% by mass.

[0068] <Other Embodiments> The following describes other embodiments of a method for producing a dispersion composition comprising a dispersed phase, a non-aqueous dispersion medium, and a dispersant using a dispersion apparatus. In this method, the raw material composition comprises a dispersed phase, a non-aqueous dispersion medium, and a dispersant, and the dispersion composition can be obtained by supplying the raw material composition from a supply mechanism to a dispersion mechanism and performing a dispersion treatment. The dispersion apparatus described above can be used to produce the dispersion composition.

[0069] In dispersion compositions in which a dispersed phase is dispersed in a non-aqueous dispersion medium using a dispersant, it is preferable that the dispersant is soluble in the non-aqueous dispersion medium and has the property of adsorbing to the dispersed phase in the non-aqueous dispersion medium. In such dispersion compositions, the types of the non-aqueous dispersion medium, dispersed phase, and dispersant are appropriately selected for dispersion stability. On the other hand, when the dispersion composition is added to other solvents such as water, the dispersant may detach from the dispersed phase due to factors such as low solubility of the dispersant in the other solvent, reducing dispersion stability and making the dispersed phase more prone to aggregation.

[0070] Therefore, the cooling liquid medium is preferably a liquid medium that does not produce solid precipitates at 25°C when mixed with a non-aqueous dispersion medium solution containing 5% by mass of the dispersant at a mass ratio of 1:1. Specifically, at 25°C and 1 atm, a non-aqueous dispersion medium solution containing 5% by mass of the dispersant contained in the raw material composition is mixed with the cooling liquid medium at a mass ratio of 1:1, stirred at 2000 rpm for 30 seconds using a rotation-orbit stirring device, filtered through a 30 μm mesh filter, and the solid content (X mass%) of the filtrate is measured. Precipitation can be determined to have occurred if the solid content of the filtrate has decreased by 5% or more from the theoretical solid content (2.5 mass%). Specifically, it is determined that no solid precipitates have occurred if the formula "(2.5 mass% - X mass%) / 2.5 mass%) × 100" is less than 5%. If the dispersant does not dissolve in the non-aqueous dispersion medium at a concentration of 5% by mass, the above test should be performed at the maximum concentration at which it can dissolve, and precipitation should be judged if the amount decreases by 5% or more from the theoretical solid content.

[0071] In yet another embodiment, at 25°C, the cooling liquid medium is preferably a liquid medium that dissolves 0.1% by mass or more of the dispersant contained in the raw material composition. The solubility of the dispersant in the cooling liquid medium is evaluated at 25°C and 1 atmosphere. The solubility of the dispersant in the cooling liquid medium is expressed as the percentage of the mass of the dispersant relative to the total mass of the dispersant and the cooling liquid medium. The solubility of the dispersant in the cooling liquid medium is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more. By dissolving the dispersant of the raw material composition in the cooling liquid medium, even if the raw material composition leaks from the supply mechanism and comes into contact with the cooling liquid medium, the deterioration of the dispersant's function is suppressed, the stability of the system is maintained, and aggregation of the dispersed phase can be prevented.

[0072] Specifically, the solubility of a dispersant in a cooling liquid medium can be determined by following the procedure below. (1) Prepare a liquid medium containing a predetermined amount (Y mass%) of dispersant relative to the total amount of cooling liquid medium and dispersant, and mix the liquid medium by stirring at 1500 rpm for 24 hours using a high-speed homodisperser. If the dispersant lumps are large, cut them into pieces smaller than 1 cm before use. (2) After filtering using a 30 μm mesh filter, measure the solid content (X mass%) of the filtrate. Dissolution is determined if the percentage decrease in the solid content (X mass%) of the filtrate from the theoretical solid content (Y mass%), "(Y mass% - X mass%) / Y mass%) × 100", is less than 20%.

[0073] <Further embodiments> Further embodiments of a method for producing a dispersed composition using a dispersion apparatus will be described below. The dispersion apparatus described above can be used to produce the dispersed composition.

[0074] According to this embodiment, a method for producing a dispersed composition is provided, which uses a dispersion apparatus comprising a dispersion mechanism for dispersing a raw material composition, a supply mechanism equipped with a plunger portion for supplying the raw material composition to the dispersion mechanism, and a cooling mechanism for cooling the plunger portion using a cooling liquid medium, wherein the method for producing a dispersed composition satisfies at least one of the following (i), (ii), and (iii). (i) The raw material composition comprises a non-aqueous dispersion medium and a dispersed phase, and the cooling liquid medium is a liquid medium having 0 to 50 particles of 10 μm or larger in the following coagulation test. (Agglomeration test) A method is used in which the same composition as the raw material composition is dispersed using a bead mill or high-pressure homogenizer to prepare a test dispersion with a particle size of less than 10 μm using a grindometer (0-100 μm), the test dispersion and a cooling liquid medium are mixed in a mass ratio of 1:1 at 25°C to prepare a test sample, and the number of particles of 10 μm or larger in the test sample is confirmed using a grindometer (0-100 μm). (ii) The raw material composition comprises a dispersed phase, a non-aqueous dispersion medium, and a dispersant. The cooling liquid medium is a liquid medium in which no solid precipitates are formed at 25°C when a solution of the non-aqueous dispersion medium containing 5% by mass of the dispersant is mixed with the cooling liquid medium in a mass ratio of 1:1. (iii) The raw material composition comprises a dispersed phase, a non-aqueous dispersion medium, and a dispersant, and at 25°C, the cooling liquid medium is a liquid medium that dissolves 0.1% by mass or more of the dispersant contained in the raw material composition.

[0075] In this embodiment, it is sufficient to satisfy at least one of (i), (ii), and (iii). Preferably, (i) is satisfied. If the raw material composition contains a dispersant, it is more preferable to satisfy (ii) or (iii) in addition to (i), and even more preferable to satisfy (ii) and (iii) in addition to (i). [Examples]

[0076] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples unless it exceeds the gist of the invention. Unless otherwise specified, "parts" refers to "parts by mass" and "%" refers to "percentage by mass".

[0077] (dispersion device) In Example 1, dispersion was performed using a valve-type high-pressure homogenizer, "HC3-5" (product name), manufactured by Sanmaru Machinery Industry Co., Ltd. In Example 2, a dispersion composition, dispersed in one pass using a nozzle-type high-pressure homogenizer, "Starburst 100" (product name), manufactured by Sugino Machine Co., Ltd., under operating conditions of 100 MPa in a single nozzle chamber, was dispersed using a valve-type high-pressure homogenizer, "HC3-5" (product name), manufactured by Sanmaru Machinery Industry Co., Ltd. The dispersion conditions are as shown in Table 1. In the table, Ex. indicates the example number and No. indicates the formulation number. The cooling mechanism is as shown in Figure 2. The cooling liquid medium was supplied to the cooling liquid medium tank of the cooling mechanism, and the cooling liquid medium was circulated at a flow rate of 2 L / H while the dispersion device was operating.

[0078] (Raw material composition) The following formulation was used to mix the components as the raw material composition. Prescription 1; Carbon nanotubes (Kumho Corporation, "Product Name: 100P") 3% by mass N-methyl-2-pyrrolidone (NMP) 96% by mass Dispersant (Zeon Corporation, product name: Zetpol2010L) 1% by mass

[0079] Prescription 2; Carbon nanotubes (Kumho Corporation, "Product Name: 100P") 2% by mass Butyl acetate 90% by mass Dispersant (BYK product name: DISPERBYK111, 95% solids content) 8% by mass

[0080] Prescription 3; Carbon black (manufactured by Denka Co., Ltd., product name: Denka Black Granules) 20% by mass N-methyl-2-pyrrolidone (NMP) 78.95% by mass Dispersant (Sigma-Aldrich "Product Name: Polyacrylonitrile Mw150,000" 1% by mass) pH adjuster (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., "product name: Sodium Hydroxide") 0.05% by mass

[0081] Prescription 4; Titanium dioxide (manufactured by Ishihara Sangyo Co., Ltd., product name: CR-95) 50% by mass Methyl ethyl ketone 44.0% by mass Dispersant (manufactured by Lubrizol Japan, product name: DISPERBYK182, solids content 43%) 6.0% by mass

[0082] Prescription 5; ITO (manufactured by Mitsubishi Materials Corporation, product name "E-ITO") 9% by mass α-terpineol 87% by mass Dispersant (BYK product name: DISPERBYK111, 95% solids) 1% by mass

[0083] Prescription 6; Carbon nanotubes (Kumho Corporation, "Product Name: 100P") 1% by mass Methyl ethyl ketone (MEK) 89% by mass Dispersant (BASF product name: EFKA PX4320, 50% solids) 10% by mass

[0084] (cooling liquid medium) The cooling liquid media shown in Table 1 were prepared.

[0085] (Agglomeration test) For the combinations of raw material compositions and cooling liquid media shown in Table 1, agglomeration tests were conducted according to the following procedure. The agglomeration tests were performed in an environment of 25°C. (1) Disperse the same composition as the raw material composition using a bead mill to prepare a test dispersion with a particle size of less than 10 μm as measured by a grindometer (0-100 μm). The dispersion apparatus used is the "Star Mill LMZ2" manufactured by Ashizawa Finetech Co., Ltd. The dispersion conditions are a peripheral speed of 12 m / s, and pass dispersion is performed until the particle size is less than 10 μm. (2) Measure 10 g of the test dispersion and 10 g of the cooling liquid medium into a stirring container (Kinki Container Co., Ltd. "001 stirring container"), and stir with a sinker mixer at 2000 rpm for 30 seconds to prepare the test sample. (3) Within 60 seconds after preparing the test sample, the number of particles 10 μm or larger in the test sample shall be confirmed using a grindometer (0-100 μm).

[0086] <Grindmeter> The grindometers used in (1) and (3) of the coagulation test are as follows: Gauge model number: "GS0-100" manufactured by Taisuke Kikai Co., Ltd. Groove depth: 0 μm to 100 μm, Graduation interval: 10 μm

[0087] <Judgment criteria> The results of the agglutination test were evaluated based on the number of particles 10 μm or larger identified in the test samples, according to the following criteria. The results are shown in Table 1. ○: No particles larger than 10 μm (no aggregation occurred) △: Contains 1 to 50 particles larger than 10 μm (slight aggregation is occurring) ×: 51 or more particles larger than 10 μm (aggregation has occurred)

[0088] (Evaluation of gland packing lifespan) Using the raw material compositions and cooling liquid media combinations shown in Table 1, a dispersion apparatus was operated for 100 hours. For each 100 hours of operation, the amount of raw material composition leaking from the supply mechanism (plunger section) and the amount of raw material composition supplied were measured, and the leakage rate (%) was calculated using the following formula (1). Leakage rate (%) = (Amount of raw material composition leaking from the supply mechanism (L) / Amount of raw material composition processed (L)) × 100 (1)

[0089] The amount of raw material composition leaking from the supply mechanism was determined according to the following procedure. (1) When replacing the gland packing, the cooling fluid medium is also replaced. Let the amount of cooling fluid medium at this time be X(L). (2) Let Y (L) be the amount of liquid recovered in the cooling fluid tank when the total operating time reaches 100 hours. The amount of leakage of the raw material composition from the supply mechanism is calculated using the following formula. Leakage amount of raw material composition from the supply mechanism (L) = Y(L) - X(L)

[0090] Based on the leakage rate obtained above, the results of the coagulation test were evaluated according to the following criteria. The results are shown in Table 1. <Judgment criteria> ○: Leakage rate 0.10% or less △: Leakage rate exceeding 0.10% but less than or equal to 0.20% ×: Leakage rate exceeding 0.20%

[0091] (Precipitation test) Precipitation tests were conducted for the dispersant and cooling liquid medium combinations shown in Table 1, following the procedure outlined below. The precipitation tests were performed at 25°C. (1) Dissolve the dispersant contained in the raw material composition in a non-aqueous dispersion medium at a concentration of 5% by mass. (2) Weigh 30 g of a non-aqueous dispersion medium solution in which the dispersant is dissolved at a concentration of 5% by mass, and 30 g of a cooling liquid medium into a stirring container (Kinki Container Co., Ltd. "001 stirring container"), and stir with a sinker mixer at 2000 rpm for 30 seconds. (3) After filtering using a 30 μm mesh filter, the solid content of the filtrate is measured. Precipitation is determined to have occurred when the solid content of the filtrate (X mass%) decreases by 5% or more compared to the theoretical solid content (2.5 mass%), specifically when the formula "((2.5 mass% - X mass%) / 2.5 mass%) × 100" satisfies 5% or more. The solid content of the filtrate is calculated using the following formula, using the mass before and after weighing 5 g of the filtrate into an aluminum dish and drying it in an oven at 200°C for 2 hours. Solids content (mass%) = ((Mass of aluminum dish + filtrate after 2 hours at 200°C) / (Mass of aluminum dish + filtrate)) × 100

[0092] <Judgment criteria> The results of the precipitation test were evaluated according to the following criteria. The results are shown in Table 1. ○: The solid content of the filtrate decreases by less than 5% from the theoretical solid content (2.5% by mass), or does not decrease (no precipitation occurs). ×: The solid content of the filtrate decreases by more than 5% compared to the theoretical solid content (2.5% by mass) (precipitation has occurred).

[0093] (Dissolution test) Dissolution tests were conducted for the dispersant and cooling liquid medium combinations shown in Table 1, following the procedure outlined below. The dissolution tests were performed at 25°C. (1) 499.5 g of the cooling liquid medium and 0.5 g of the dispersant contained in the raw material composition are weighed into a 1 L container, and stirred at 1500 rpm for 24 hours using a high-speed homodisperser to prepare a cooling liquid medium containing 0.1 mass% of the dispersant. (2) After filtering using a 30 μm mesh filter, the solid content of the filtrate is measured. If the solid content of the filtrate (X mass%) is 20% or more less than the theoretical solid content (0.1 mass%), specifically if the formula "((0.1 mass% - X mass%) / 0.1 mass%) × 100" satisfies 20% or more, it is determined that the filtrate has not dissolved. The solid content of the filtrate is calculated using the following formula, using the mass before and after weighing 5 g of the filtrate into an aluminum dish and drying it in an oven at 200°C for 2 hours. Solids content (mass%) = ((Mass of aluminum dish + filtrate after 2 hours at 200°C) / (Mass of aluminum dish + filtrate)) × 100

[0094] <Judgment criteria> The results of the dissolution test were evaluated according to the following criteria. The results are shown in Table 1. ○: The solid content of the filtrate decreases by less than 20% from the theoretical solid content (0.1% by mass), or does not decrease (dissolved). ×: The solid content of the filtrate decreases by more than 20% compared to the theoretical solid content (0.1% by mass) (not dissolved).

[0095] [Table 1-1]

[0096] [Table 1-2]

[0097] The table above shows that in cases where no aggregates were generated in the agglomeration test, the leakage rate of the cooling fluid from the plunger was reduced, and the lifespan of the gland packing was extended. Similarly, in cases where only a small number of aggregates were generated, the leakage rate of the cooling fluid from the plunger was reduced, and the lifespan of the gland packing was extended. Conversely, in cases where a large number of aggregates were generated in the agglomeration test, the leakage rate of the cooling fluid from the plunger increased, and the lifespan of the gland packing was shortened.

[0098] Precipitation tests show that when a non-aqueous dispersion medium containing 5% by mass of dispersant is mixed with a cooling liquid medium in a 1:1 mass ratio and no solid precipitates are observed, the lifespan of the gland packing is extended. Agglomeration tests show that when the dispersant is found to be dissolved in a cooling liquid medium containing 0.1% by mass of dispersant, the lifespan of the gland packing is extended.

[0099] Although the present invention has been described with reference to several embodiments described above, the present invention is not limited to these embodiments. Various modifications can be made to the configuration and details of the present invention within the scope of the invention.

[0100] The disclosures of this application relate to the subject matter described in Japanese Patent Application No. 2022-014907, filed on 2 February 2022, all of which are incorporated herein by reference. [Explanation of Symbols]

[0101] 10 Plunger, 20 High-pressure pump, 21 Cylinder section, 24 Gland packing, 30 Dispersion section, 31 Valve seat, 32 Impact ring, 33 Homo valve, 40 Cooling mechanism, 41 Cooling liquid medium tank, 42 ​​Cooling section, 43 Recovery container, 50 Raw material composition tank, 100 Dispersion device

Claims

1. A dispersion mechanism for dispersing the raw material composition, A supply mechanism comprising a plunger section for supplying the raw material composition to the dispersion mechanism, A method for producing a dispersion composition using a dispersion apparatus that includes a cooling mechanism for cooling the plunger portion using a cooling liquid medium, The aforementioned raw material composition comprises a non-aqueous dispersion medium and a dispersed phase. A method for producing a dispersion composition, wherein the cooling liquid medium is a liquid medium having 0 to 50 particles of 10 μm or larger in the following agglomeration test. (Agglomeration test) A test dispersion is prepared by dispersing the same composition as the raw material composition using a bead mill or high-pressure homogenizer, and measuring the particle size with a grindometer (0-100 μm) to less than 10 μm. A method for preparing a test sample by mixing the test dispersion and the cooling liquid medium in a mass ratio of 1:1 at 25°C, and confirming the number of particles of 10 μm or larger in the test sample using a grindometer (0 to 100 μm).

2. A method for producing a dispersion composition according to claim 1, wherein the non-aqueous dispersion medium of the raw material composition and the cooling liquid medium are the same liquid medium.

3. A method for producing a dispersion composition according to claim 1 or 2, wherein the leakage rate of the raw material composition from the supply mechanism represented by the following formula (1) is 0.2% or less per 100 hours of operation. Leakage rate (%) = (Amount of raw material composition leaking from the supply mechanism (L) / Amount of raw material composition supplied (L)) × 100 (1)

4. A dispersion mechanism for dispersing the raw material composition, A supply mechanism comprising a plunger section for supplying the raw material composition to the dispersion mechanism, A method for producing a dispersion composition using a dispersion apparatus that includes a cooling mechanism for cooling the plunger portion using a cooling liquid medium, A method for producing a dispersion composition, wherein the raw material composition comprises a disperse, a non-aqueous dispersion medium, and a dispersant, and the cooling liquid medium is a liquid medium in which no solid precipitates are formed at 25°C when a solution of the non-aqueous dispersion medium containing 5% by mass of the dispersant is mixed with the cooling liquid medium in a mass ratio of 1:

1.

5. A dispersion mechanism for dispersing the raw material composition, A supply mechanism comprising a plunger section for supplying the raw material composition to the dispersion mechanism, A method for producing a dispersion composition using a dispersion apparatus that includes a cooling mechanism for cooling the plunger portion using a cooling liquid medium, The aforementioned raw material composition comprises a dispersant, a non-aqueous dispersion medium, and a dispersant. A method for producing a dispersion composition, wherein at 25°C, the cooling liquid medium is a liquid medium that dissolves 0.1% by mass or more of the dispersant contained in the raw material composition.

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