Method for producing a dispersion

Abstract

A method for producing a dispersion, wherein a multiphase fluid is flowed in the following order: first at a first flow velocity through a first pipe, second at a second flow velocity through a constricted passage, and third at a third flow velocity through a second pipe. The second flow velocity can be faster than the first flow velocity. The first ratio is 5 or greater. The first ratio is the ratio of the second flow velocity to the flow velocity at a first reference point. The first reference point is the first candidate point furthest upstream when a first candidate point set in the first pipe is moved along the flow direction of the multiphase fluid, such that the first reference ratio is 5 or greater. The first reference ratio is the ratio of the flow velocity at a point located 15 mm downstream of the first candidate point to the flow velocity at the first candidate point. The multiphase fluid can be a mixture of a liquid continuous phase and one or more dispersed phases selected from other liquids, solids, and gases.

Description

[Technical Field]

[0001] This disclosure relates to a method for producing a dispersion, as well as a system and method thereof. [Background technology]

[0002] Generally, dispersions were formed by disrupting the flow state by narrowing the flow path or installing baffles. For example, Patent Document 1 describes a stationary mixing apparatus comprising at least two plate-like bodies having through holes. One plate-like body has multiple through holes, while the other plate-like body has one through hole. Due to the difference in the number of through holes, the fluid passing through the through holes collides violently with each other or with the plate-like bodies. This can form a flow accompanied by vortices, causing cavitation. Also, due to the difference in the number of through holes, fluid separation and convergence occur, and strong shear forces act on the fluid. This can potentially result in a dispersion of fine particles. Patent Document 2 describes a method for producing an emulsified dispersion using a flow-through tube type tubular emulsifier having one or more sets of two plates with holes inside a flow-through tube. The holes in the plates are offset from each other. As a result, when a fluid (dispersion, dispersion medium, and surfactant) is flowed at high speed, the flow is disturbed, the fluid collides, and the flow splits. Continuous emulsification and dispersion is said to be achieved by the droplet-breaking force due to the liquid collision, the cavitation effect caused by the jet of fluid generated when the fluid passes through the plates at high speed, and the strong shear force, dispersion force, and stirring force when the fluid is split at the holes.

[0003] Patent Document 3 describes an orifice in which a narrowed diameter section on the inflow side of a fluid containing particle aggregates and an expanded diameter section on the outflow side are connected by a constricted opening. The constricted opening is a passage point for the aggregates, with a diameter smaller than that of the narrowed and expanded sections, and the length of the flow path in the flow direction is very short. Turbulence is generated when the fluid passes through the constricted opening, which promotes the de-aggregation of the aggregates. It is said that re-aggregation can be suppressed in the expanded diameter section. Patent Document 4 describes a micromixer having a liquid flow pipe and a liquid confluence and dispersion section. The liquid flow pipe is divided into an aqueous component channel and an oily component channel, allowing the aqueous and oily components to flow separately. The liquid confluence and dispersion section has a liquid confluence section, a microchannel, and a channel expansion section. At the liquid confluence section, the oily component is combined with the aqueous component so that it is surrounded by the aqueous component. The combined fluid flows out to the channel expansion section through the microchannel in a laminar flow state. In this way, the flow of the aqueous and oily components is controlled, and the combined fluid is circulated while maintaining a laminar flow state. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-255320 [Patent Document 2] Japanese Patent Publication No. 2003-260343 [Patent Document 3] Japanese Patent Publication No. 2017-3066 [Patent Document 4] Japanese Patent Publication No. 2010-142725

[0005] The background art described herein is intended to provide general context for the disclosure. Within the scope of the background art section, the works of the named inventors are not, explicitly or implicitly, considered prior art to this disclosure, similar to descriptions that may not be recognized as prior art at the time of filing. [Overview of the project]

[0006] A method for producing a dispersion (hereinafter referred to as a method for producing a dispersion, or simply a method) is disclosed or implemented. The method for producing the dispersion described above allows the multiphase fluid to flow in the following order: into the first pipe at a first flow velocity, into the constricted passage at a second flow velocity, and into the second pipe at a third flow velocity. The first flow velocity can be between 0.02 m / s and 10 m / s. In the aforementioned constricted flow passage, the multiphase fluid can be flowed at the second flow velocity for 5 mm or more. The second flow velocity can be faster than the first flow velocity. The second flow velocity can be a flow velocity that changes or remains constant along the constricted flow passage within a range of 5 m / s to 110 m / s. The second flow velocity can have a ratio of 5 or more to the first flow velocity. The first ratio can be the ratio of the second flow velocity to the flow velocity at the first reference point (second flow velocity / flow velocity at the first reference point). The first reference point can be the first candidate point furthest upstream when the first reference ratio is 5 or greater when the first candidate point set in the first piping is moved along the flow direction of the multiphase fluid. The first reference ratio can be the ratio of the flow velocity at a point located 15 mm downstream of the first candidate point to the flow velocity at the first candidate point (flow velocity at the point located 15 mm downstream of the first candidate point / flow velocity at the first candidate point). In the second piping, it is preferable to flow the multiphase fluid at a third flow velocity of 3 mm or more. The third flow velocity can be 10 m / s or less. The multiphase fluid may be a mixture of a liquid continuous phase and one or more dispersed phases selected from other liquids, solids, and gases. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a graph showing the relationship between the arrangement of upstream piping, constriction passages, and downstream piping and the flow velocity. [Figure 2] Figure 2(A) is a schematic cross-sectional view showing the relationship between the first reference point of the upstream piping and the inlet of the constricted passage, and the relationship between the outlet of the constricted passage and the downstream piping located 15 mm downstream from there. Figure 2(B) is a schematic graph showing the change in flow velocity V(p) at an arbitrary position P. Figure 2(C) is a schematic graph showing the change in the flow velocity ratio V(p+15mm) / V(p) at an arbitrary position P. [Figure 3] Figures 3(A) to (C) are diagrams schematically showing another embodiment of Figures 2(A) to (C). [Figure 4] Figures 4(A) to (C) are photographs substituted for drawings showing the state where the dispersed phase deforms as the multiphase fluid flows from the upstream pipe to the constricted flow passage. [Figure 5] Figure 5 is a cross-sectional view schematically showing an example of a static dispersion apparatus used in the method for producing a dispersion liquid of the present invention. [Figure 6] Figure 6 is a cross-sectional view schematically showing another example of the static dispersion apparatus used in the method for producing a dispersion liquid of the present invention. [Figure 7] Figure 7 is a cross-sectional view schematically showing still another example of the static dispersion apparatus used in the method for producing a dispersion liquid of the present invention. [Figure 8] Figure 8 is a cross-sectional view schematically showing an embodiment in which a plurality of constricted flow passages are arranged in parallel in the in-plane direction of a plane perpendicular to the flow direction of the multiphase fluid. [Figure 9] Figures 9(A) to (C) are partial cross-sectional views schematically showing examples of the inflow angle at the flow passage inlet of the constricted flow passage. [Figure 10] Figures 10(A) to (D) are partial cross-sectional views schematically showing other examples of the inflow angle at the flow passage inlet of the constricted flow passage. [Figure 11] Figure 11 is a partial cross-sectional view schematically showing an example in which the intersecting portion of the wall surfaces constituting the flow passage inlet of the constricted flow passage is chamfered. [Figure 12] Figures 12(A) to (C) are partial cross-sectional views schematically showing examples of the separation distance between the flow passage outlet of the first constricted flow passage and the flow passage inlet of the second constricted flow passage, where a plurality of constricted flow passages are arranged in the aforementioned flow direction. [Figure 13] Figure 13 is a configuration diagram schematically showing the circulation mixer used in each of the Examples and Comparative Examples. [Figure 14] Figure 14 is a graph showing the test results of Example 7 and Comparative Example 6. Detailed Description of the Invention

[0008] The present invention can be considered to relate to a method for producing a dispersion that can create a finer dispersion productively by splitting a dispersed phase (liquid, solid, or gas) with low energy and high efficiency, for example. The dispersion apparatus according to this disclosure may be referred to as, or considered to be, a mixer.

[0009] As described in the aforementioned Patent Documents 1-3, when the flow state is disturbed and the dispersed phase is deformed and split by shear force, energy is lost as a rotating component is added to the dispersed phase. Therefore, there is room for improvement in terms of energy efficiency and productivity of conventional stationary dispersion devices. Furthermore, the micromixer described in Patent Document 4 must perform processing while maintaining a precise laminar flow state. Therefore, it may not be possible to increase the processing capacity (for example, sufficiently) due to its structure, and there is room for improvement in terms of productivity.

[0010] In contrast, the method for producing a dispersion according to the present invention allows for the efficient and low-energy splitting of the dispersed phase, thereby forming a finer dispersion with high productivity. These and other purposes of this disclosure are achieved individually or in combination by the following discoveries:

[0011] Numerical limits or ranges described herein include the terminal values ​​indicated within those limits or ranges. Furthermore, all values ​​and subranges within the numerical limits or ranges are explicitly included as specified. As used herein, singular words and other similar terms mean "one or more." Various modifications and alterations are possible in one or more embodiments of the present invention. Therefore, it should be understood that, for example, within the technical scope based on the claims, embodiments not explicitly stated herein can also be implemented in one or more embodiments of the present invention. All the contents of the above and below patent documents and other documents are fully incorporated herein by reference, as they are described in detail.

[0012] The method for producing the dispersion of the present invention will be described below. The method for producing a dispersion according to the present invention is carried out using a multiphase fluid obtained by mixing a liquid continuous phase with one or more dispersed phases selected from other liquids, solids, and gases. The multiphase fluid means a fluid in which two or more phases are mixed. Specifically, it means a fluid in which dispersed phases (dispersed particles) are mixed with a continuous phase (dispersion medium, matrix). The multiphase fluid serves as the raw material in the method for producing a dispersion according to the present invention.

[0013] In the method for producing the dispersion of the present invention in one or more embodiments, the various multiphase fluids can be appropriately circulated in this order through a flow pipe having an upstream pipe, a constricted flow passage, and a downstream pipe as shown below. Upstream piping typically has a flow path that allows the multiphase fluid to flow into the constricted passage. Ideally, this flow path can supply liquid to the constricted passage while minimizing pressure loss to the multiphase fluid. The aforementioned multiphase fluid can be formed by pre-mixing the continuous phase and the dispersed phase upstream of the upstream piping. Alternatively, the aforementioned multiphase fluid can be formed by mixing the continuous phase and the dispersed phase in the upstream piping. A constricted flow passage is typically a flow path that reduces the flow diameter compared to the upstream piping, thereby rapidly increasing the flow velocity. In this passage, the dispersed phase of the multiphase fluid flowing from the upstream piping is deformed and split by the tensile force generated in the flow direction of the multiphase fluid, creating a flow field. This deforms and splits the dispersed phase, which is then dispersed and mixed with the continuous phase to form a finer dispersion. Hereinafter, "the tensile force generated in the flow direction of the multiphase fluid" will simply be referred to as "tensile force." The downstream piping typically has a flow path that allows the multiphase fluid to flow further downstream from the constricted passage. This allows the dispersion formed in the constricted passage to be supplied to the next process line, etc. In this embodiment, the upstream piping corresponds to the first piping, and the downstream piping corresponds to the second piping.

[0014] The flow of the aforementioned multiphase fluid can be carried out under the following conditions. The multiphase fluid can be flowed in the upstream piping at a first flow velocity, in the constricted passage at a second flow velocity, and in the downstream piping at a third flow velocity, in this order. The aforementioned first flow velocity can be, as an example, in a range of 0.02 m / s or more and 10 m / s or less. In the aforementioned constricted flow passage, the multiphase fluid can be flowed at the second flow velocity for 5 mm or more. The second flow velocity can be faster than the first flow velocity. The second flow velocity can be a flow velocity that varies or remains constant within the range of 5 m / s to 110 m / s. The second flow velocity is preferably such that the ratio of the first flow velocity is 5 or greater. The first ratio, according to one or more embodiments of this disclosure, is the ratio of the second flow velocity to the flow velocity at the first reference point (second flow velocity / flow velocity at the first reference point). The first reference point is the first candidate point furthest upstream when the first candidate point set in the first piping is moved along the flow direction of the multiphase fluid, such that the first reference ratio is 5 or more. The first reference ratio is the ratio of the flow velocity at a point located 15 mm downstream of the first candidate point to the flow velocity at the first candidate point (flow velocity at the point located 15 mm downstream of the first candidate point / flow velocity at the first candidate point). In the downstream piping, the multiphase fluid can be flowed at a third flow velocity of 3 mm or more. The third flow velocity can be 10 m / s or less according to one or more embodiments of this disclosure. The upstream piping can be considered as the section with the first flow velocity, the constricted passage can be considered as the section with the second flow velocity, and the downstream piping can be considered as the section with the third flow velocity. Figure 1 shows an example of flow velocity in a static dispersion device including an upstream pipe 1, a constricted passage 21, and a downstream pipe 3. First, the multiphase fluid flows through the upstream pipe 1 at a first flow velocity of 1F. Next, the flow velocity is accelerated (for example, rapidly) to a second flow velocity of 21F in the constricted passage 21. Then, the multiphase fluid flows at the second flow velocity of 21F for a distance of, for example, 5 mm or more. After that, the flow velocity is reduced (for example, rapidly) to a third flow velocity of 3F in the downstream pipe 3, and the third flow velocity of 3F can be maintained for example, 3 mm or more. Note that in the constricted passage 21, the multiphase fluid flows for a distance of 5 mm or more at the second flow velocity of 21F, so the length of the constricted passage 21 measured along the flow direction of the multiphase fluid is 5 mm or more. Similarly, in the downstream pipe 3, the multiphase fluid flows for a distance of 3 mm or more at the third flow velocity of 3F, so the length of the downstream pipe 3 measured along the flow direction of the multiphase fluid is 3 mm or more. This configuration can mean that in a stationary distributed device including upstream piping, a constricting passage, and downstream piping, the multiphase fluid is circulated from upstream to downstream at a slow-fast-slow flow velocity. In particular, in each embodiment of this disclosure, the flow velocity can be accelerated (for example, rapidly) over a short distance of 15 mm or less where the upstream piping connects to the constricting passage. That is, the flow velocity can be rapidly accelerated within a range of 15 mm upstream from the inlet of the constricting passage.

[0015] The length over which the flow velocity is maintained in the constricted passage and the length over which the flow velocity is maintained in the downstream piping refer to the lengths along the extension direction of each flow path. The length over which the flow velocity is maintained in the upstream piping also refers to the length along the extension direction of the flow path.

[0016] (Method for measuring flow velocity) In this disclosure, flow velocity represents the velocity of the fluid over the entire cross-section of the flow channel. Therefore, for example, the average fluid velocity over the entire cross-section of the flow channel, or the fluid velocity at a representative point in the cross-section of the flow channel (typically the center point of the cross-section of the flow channel, etc.) is used as the flow velocity. For each of the upstream, constricted, and downstream pipes, the liquid flow rate and the cross-sectional area of ​​the flow path are measured, and the flow velocity is calculated based on the following formula. (Flow velocity) = (Liquid flow rate) / (Cross-sectional area of ​​the flow path) The flow rate is measured by taking a sample of the flowing fluid for 10 seconds at the outlet of the downstream piping, measuring its volume, and calculating the flow rate per hour based on this. The aforementioned flow path cross-sectional area is measured by measuring the inner diameter of the piping to be used and calculating the flow path cross-sectional area from that diameter. The flow velocity calculated based on the above formula can be considered as the average flow velocity over the entire cross-section of the flow channel. Alternatively, the flow velocity may be calculated by, for example, using a fluid simulation that simulates the flow channel to be used, to determine the flow velocity at the center point of the flow channel cross-section. Furthermore, this disclosure uses the ratio of the flow velocity between two points separated in the direction of fluid flow. The ratio of the flow velocity between two points includes the first ratio and the first reference ratio described above. The ratio of the flow velocity between two points also includes the second ratio, second reference ratio, third ratio, fourth ratio, fifth ratio, etc., which will be described later. The two points used to calculate these ratios are typically points that are in the same position in a direction perpendicular to the direction of fluid flow, and preferably the center point of the flow channel cross-section is used. The distance between the two points used to calculate each ratio typically means the distance measured along the direction of fluid flow.

[0017] "Flow channel cross-section" refers to a cross-section in the flow pipe that is perpendicular to the flow direction of the multiphase fluid. Hereinafter, the "flow direction of the multiphase fluid" will be simply referred to as the "flow direction," and the in-plane direction of the plane that is perpendicular to the "flow direction of the multiphase fluid" will be simply referred to as the orthogonal plane direction. "Flow channel cross-sectional area" refers to the flow region in the flow channel cross-section, that is, the area of ​​the flow channel. "Flow channel diameter" refers to the diameter of the circular flow channel in the cross-section of the flow channel. In other words, it is the inner diameter of the pipe. "Equivalent diameter of a circle" refers to the diameter of a circle obtained by converting the aforementioned cross-sectional area of ​​the flow path into a circle having the same area. "Flow direction" refers to the direction in which the upstream piping, the constricted flow passage, and the downstream piping are connected, that is, the direction of extension of the entire flow pipe. In other words, it refers to the direction in which the multiphase fluid enters the flow pipe from the flow inlet and exits the flow pipe. "Flow channel inlet" refers to the opening of the flow channel on the upstream side. "Flow channel outlet" refers to the opening of the flow channel on the downstream side. These terms include those referring to the entire flow pipe, and those referring to the upstream piping, the constricted passage, and the downstream piping, respectively.

[0018] (Method for identifying the first reference point (P1) of the upstream piping and the flow inlet (P1+15mm) of the constricted passage, and method for measuring the first ratio) First, in a stationary distributed device including upstream piping, a constricted flow passage, and downstream piping, a combination is set between an arbitrary position (P) in the flow path and a point (P+15mm) 15mm downstream of position (P) in the flow direction, and this combination is moved along the flow direction from the flow path inlet of the upstream piping. In this embodiment, position (P) corresponds to the first candidate point. Move the above combinations to identify the combination of the furthest upstream points where the first reference ratio is 5 or greater. Here, the first reference ratio is the flow velocity V at point (P). (P) The flow velocity V at the separated point (P+15mm) located 15mm downstream from point (P) is relative to point (P). (P+15mm) The ratio (V (P+15mm) / V (P) ) The identified point (P) and the separated point (P+15mm) become the first reference point (P1) of the upstream piping and the flow inlet (P1+15mm) of the constricted passage. In other words, the first reference ratio (V (P+15mm) / V (P) The upstreammost point (P) where the value is 5 or greater is designated as the first reference point (P1). The separated point (P+15mm) located 15mm downstream of the first reference point (P1) is designated as the inlet of the constricted flow passage. And the flow velocity V at the first reference point (P1) (P1) The ratio of the second flow velocity V2 to (V2 / V (P1) This is the first ratio. Here, the second flow velocity V2 is the flow velocity in the constricted passage. In still another aspect, the first ratio can be the ratio of the second flow velocity to the flow velocity at the reference point (P1') when the specific ratio is 5 or more (second flow velocity / flow velocity at the reference point (P1') when the specific ratio is 5 or more). Here, the specific ratio can be the ratio of the flow velocity at the flow passage inlet (P1'+15mm) of the constricted flow passage to the flow velocity at the reference point (P1') of the upstream pipe located 15 mm upstream from the flow passage inlet of the constricted flow passage (flow velocity at the flow passage inlet (P1'+15mm) / flow velocity at the reference point (P1')). In this case, the combination of the position (P) and the spaced point (P+15mm) set as described above is moved from the flow passage inlet of the upstream pipe, and the flow velocity V at the point (P) in the upstream pipe (P) to the flow velocity V at the spaced point (P+15) (P+15mm) the ratio (the latter / the former) of which is 5 or more is identified as a point combination. The identified point (P) and spaced point (P+15mm) serve as the reference point (P1') of the upstream pipe and the flow passage inlet (P1'+15mm) of the constricted flow passage. Then, the flow velocity ratio (V (P1'+15mm) / V (P1') ) in the identified combination is the specific ratio. The flow velocity V at the reference point (P1') when this specific ratio is 5 or more (P1') the ratio of the second flow velocity V2 to (V2 / V (P1') ) is the first ratio. The reference point (P1') when the specific ratio is 5 or more coincides with the above-mentioned first reference point (P1). Therefore, the first ratio calculated based on the specific ratio coincides with the first ratio calculated based on the first reference point (P1).

[0019] The above identification method and measurement method will be described with reference to the examples shown in, for example, Figure 2 and Figure 3. However, this is merely an example, and the shapes of the flow passages of the upstream pipe, the constricted flow passage and the downstream pipe are not limited to the forms shown in Figure 2 and Figure 3. In the stationary dispersion device 10 shown in Figure 2(A), the flow path cross-sectional area at the flow path inlet 211 of the flow path 21A of the constricted flow passage 21 is abruptly narrowed compared to the flow path cross-sectional area of ​​the flow path 1A of the upstream piping 1. In this example, the aforementioned combination (P, P+15mm) is moved from the flow path inlet of the flow path 1A of the upstream piping 1. Within a certain range of movement, the aforementioned flow velocity ratio (first reference ratio) remains constant at less than 5 (Figure 2(C)). Subsequently, the combination that leads to the combination at the furthest upstream point where the flow velocity ratio (first reference ratio) suddenly becomes 5 or more is identified (Figures 2(B) and (C)). The identified combination becomes the first reference point (P1) of the upstream piping and the flow path inlet 211 (P1+15mm) of the constricted flow passage. Then, the flow velocity V at the first reference point (P1) (P1) The ratio of the second flow velocity V2 to (V2 / V (P1) ) is calculated as the first ratio. In the stationary device 80 shown in Figure 3(A), the flow path cross-sectional area of ​​the flow path 1A of the upstream piping 1 gradually decreases towards the flow path inlet 211 of the flow path 21A of the constricting passage 21. In this example, as the aforementioned combination (P, P+15mm) is moved from the flow path inlet of the flow path 1A of the upstream piping 1, the aforementioned flow velocity ratio (first reference ratio) gradually changes (Figure 3(C)). Subsequently, the change becomes rapidly larger, reaching the combination at the furthest upstream point where the aforementioned flow velocity ratio (first reference ratio) is 5 or more (Figures 3(B) and (C)). This combination is identified. The identified combination becomes the first reference point (P1) of the upstream piping and the flow path inlet 211 (P1+15mm) of the constricting passage. Then, similar to Figure 2, the flow velocity V at the first reference point (P1) (P1) The ratio of the second flow velocity V2 to (V2 / V (P1) ) is calculated as the first ratio. From another perspective, the upstream position where the first ratio is 5 can be defined as the inlet 211 of the constricting passage 21. Similarly, the downstream position where the first ratio is 5 can be defined as the outlet 212 of the constricting passage 21. Furthermore, the first ratio is 5 or greater between the inlet 211 and the outlet 212. For the second, third, fourth, and fifth ratios, the method for identifying and measuring the first ratio described above shall be modified and applied according to the position in which each ratio is used.

[0020] The aforementioned flow velocity configuration can be achieved by controlling the flow path cross-sectional areas of the upstream piping, the constricted passage, and the downstream piping to be in a large-small-large relationship. This makes it possible to achieve a (for example, rapid) increase in flow velocity from the upstream piping to the constricted passage without adding any special energy (pressure). In this case, the flow rates in the upstream piping, the constricted flow passage, and the downstream piping can be made the same. This makes it possible to further enhance the dispersion effect when the flow enters the constricted flow passage from the upstream piping, and when the flow exits the constricted flow passage into the downstream piping, without disturbing the flow field. In one or more embodiments, the constricted passage can be designed so that other types of dispersed phases do not mix in or branch off. That is, the constricted passage can be designed so that there are no confluence or branching channels for different agents. Thus, the constricted passage can provide a flow path for a multiphase fluid consisting of one or more separate channels that are separated from each other. This allows for a greater dispersion effect without disturbing the flow field when the liquid enters the constricted section.

[0021] By creating a (for example, abrupt) difference in flow velocity between the upstream piping and the constricted passage, the shear force with a rotational component applied to the multiphase fluid in the upstream piping can be minimized. As a result, the tensile force applied to the multiphase fluid in the constricted passage can be applied with lower energy (lower pressure). The explanation will be given with reference to Figures 4(A) to 4(C). The multiphase fluid 8 fills the flow path 1A of the upstream piping 1. In Figure 4(A), the dispersed phase 81 in the multiphase fluid 8 is spherical. In Figure 4(B), the dispersed phase 81 enters the flow path inlet 211 of the constricted passage 21. From this point, it is being pulled and deformed along the flow direction Y of the multiphase fluid. In Figure 4(C), as the dispersed phase 81 moves within the flow path 21A of the constricted passage 21, it deforms into a more elongated state.

[0022] By allowing the aforementioned flow velocity to flow through the constricted passage for a predetermined length or longer, a flow field of sufficient length can be formed. As a result, the shear stress with a rotational component can be kept as small as possible in the constricted flow passage. While maintaining this state, the tensile force due to the aforementioned flow velocity difference is further increased. This allows the dispersed phase of the multiphase fluid to be sufficiently deformed and split, and the particle size can be made finer. Furthermore, in the constricted passage, the finely divided particles of the dispersed phase are dispersed into the continuous phase and mixed. In each embodiment of the present disclosure, cavitation may not be introduced or may not be necessary. At least for this reason, pressure loss can be suppressed in the constricted passage. Then, the tensile force can be effectively applied at a lower pressure to deform and split the dispersed phase. As a result, for example, a finer dispersion can be formed more efficiently with less energy than when the dispersed phase is deformed and split by conventional shear stress. For example, the energy (pressure) applied in the dispersion manufacturing method of the present disclosure can be reduced to about 1 / 100th of the energy applied in a conventional high-pressure homomixer. Furthermore, since the constricted flow passage can be considered specialized for mixing under tensile force, precise control of the flow of the dispersed phase and the continuous phase may not be introduced or required. At least for this reason, a finer dispersion can be efficiently formed with lower energy using a multiphase fluid from the outset, without separating the dispersed phase and the continuous phase. In this way, the dispersed phase is deformed and split by the tensile force, dispersed into the continuous phase as fine particles, and mixed to form a fine dispersion with high productivity.

[0023] Creating a (for example, abrupt) difference in flow velocity between the constricted passage and the downstream piping, as described above, can mean (for example, abruptly) reducing the flow velocity in the constricted passage in the downstream piping, provided there are no obstructions to the flow of the dispersion in the downstream piping. This (for example, abrupt) reduction can suppress flow turbulence while preventing an increase in pressure (energy). This maintains a good dispersion state of the dispersion and allows the tensile force to act on the dispersed phase more efficiently and effectively. The aforementioned (e.g., rapid) deceleration of the flow velocity can also be said to be a result of volumetric change. When the dispersed phase is released from the constricted passage to the downstream piping, it is released into a larger volume portion, thereby applying further tensile force to the dispersed phase. Furthermore, by maintaining the aforementioned flow velocity for a predetermined length or longer in the downstream piping, it is possible to ensure sufficient flow without unnecessary obstacles during the deformation of the dispersed phase. This makes the deformation of the dispersed phase more efficient. In this state, by flowing the dispersion at the aforementioned flow velocity for a predetermined length or longer, no excessive energy is added to the dispersion formed in the constricted flow passage. Furthermore, the dispersion can be circulated downstream while maintaining low energy levels. In other words, there is no need to perform spraying that requires additional energy on the dispersion formed in the constricted flow passage. The dispersion can then be stably supplied to the next process line, etc.

[0024] According to the method for producing a dispersion of the present invention, the dispersed phase can be dispersed with low energy and high efficiency, making it possible to produce a finer dispersion with high productivity. The method for producing the dispersion of the present invention includes, for example, a form in which the dispersed phase and the continuous phase are liquids that are insoluble in each other, and the dispersed phase is emulsified and mixed. Note that the insolubility of the dispersed phase and the continuous phase means that the liquid of the dispersed phase does not dissolve in the liquid of the continuous phase. Furthermore, the method for producing the dispersion of the present invention includes, for example, a form in which the dispersed phase is a solid pigment or other secondary particle (aggregate, aggregated particle). In this case, the secondary particle is crushed and dispersed, and then dispersed and mixed into the continuous phase.

[0025] The method for producing dispersions of the present invention can utilize a flow field. This allows for a wider range of types of multiphase fluids (raw materials) to be dispersed compared to conventional dispersion devices that utilize shear force. For example, when the ratio of the viscosity of the dispersed phase to the viscosity of the continuous phase is high (for example, when the ratio is 3 or more), it may be difficult to achieve deformation and splitting of the dispersed phase with low energy using conventional shear force. In each embodiment of the present invention, this can be done with low energy. As described above, the method for producing the dispersion of the present invention allows for the control of the flow velocity in the upstream piping, constricted passage, and downstream piping from slow to fast to very slow. This enables specialization of mixing by tensile force rather than shear force. For this reason at least, it is possible to increase the processing volume by appropriately expanding the size of the flow pipes without impairing the effects of the present invention. For example, it is possible to achieve a processing volume of 100 L / hour or more. In other words, the static dispersion device of the present invention can achieve a sufficient processing volume that was not believed to be achievable with conventional orifices, micromixers, or conventional dispersion devices that utilize turbulence in the flow state.

[0026] The first flow velocity is preferably 0.02 m / sec or higher, more preferably 0.1 m / sec or higher, and even more preferably 0.4 m / sec or higher, from the viewpoint of improving the mixability of the liquid. From the viewpoint of reducing pressure loss other than mixing, the first flow velocity is preferably 10 m / sec or less, more preferably 6 m / sec or less, and even more preferably 3 m / sec or less. Furthermore, the flow velocity at the first reference point (P1) of the upstream piping is also the first flow velocity. In other words, the range of the flow velocity at the first reference point (P1) is the same as the first flow velocity described above.

[0027] The length over which the multiphase fluid flows within the aforementioned first flow velocity range is preferably 3 mm or more, more preferably 5 mm or more, and even more preferably 10 mm or more, from the viewpoint of regulating the flow of the liquid before it enters the constricted passage. The length over which the multiphase fluid flows within the aforementioned first flow velocity range is preferably 1,000 mm or less, more preferably 500 mm or less, and even more preferably 100 mm or less, from the viewpoint of making the piping compact and improving the maneuverability of the equipment.

[0028] The second flow velocity is preferably faster than the first flow velocity and is a flow velocity that changes or remains constant within the following range along the constricted flow passage. The second flow velocity is preferably 5 m / sec or more, more preferably 10 m / sec or more, and even more preferably 15 m / sec or more, from the viewpoint of obtaining good emulsification and dispersion effects. The second flow velocity is preferably 110 m / s or less, more preferably 95 m / s or less, and even more preferably 80 m / s or less, from the viewpoint of suppressing an increase in pressure loss. As described above, the second flow velocity is preferably such that the first ratio, which is the ratio of the second flow velocity to the flow velocity at the first reference point (P1), is 5 or more. As described above, the first reference point (P1) is the first reference ratio (V), which is the ratio of the flow velocity at the separated point (P+15mm) to the flow velocity at point (P). (P+15mm) / V (P) The upstream point (P) is where the ratio is 5 or greater, and the inlet of the constricted flow passage is located at a separated point (P1+15mm) 15mm downstream from the first reference point (P1). This means that the flow velocity at the inlet of the constricted flow passage (P1+15mm) is 5 times or more the flow velocity at the first reference point (P1). Furthermore, it is preferable that the first ratio is 5 or greater. In other words, it is preferable that the second flow velocity is 5 times or more the flow velocity at the first reference point (P1). Furthermore, considering the specific ratio described above, it is preferable that the second flow velocity is such that the first ratio, which is the ratio of the second flow velocity to the flow velocity at the reference point (P1') when the specific ratio is 5 or more, is 5 or more. Here, a specific ratio of 5 or more means that the flow velocity at the inlet of the constricted passage is 5 times or more the flow velocity at the reference point (P1'). In addition, it is preferable that the first ratio is 5 or more. In other words, it is preferable that the second flow velocity is 5 times or more the flow velocity at the reference point (P1').

[0029] The length over which the multiphase fluid flows within the aforementioned second flow velocity range is preferably 5 mm or more, more preferably 7 mm or more, and even more preferably 8 mm or more, from the viewpoint of regulating the liquid flow. From the viewpoint of suppressing pressure loss, the length over which the multiphase fluid flows within the second flow velocity range is preferably 100 mm or less, more preferably 70 mm or less, and even more preferably 50 mm or less.

[0030] In practice, the third flow velocity is preferably 0.02 m / sec or more, more preferably 0.1 m / sec or more, and even more preferably 0.4 m / sec or more. The third flow velocity is preferably 10 m / s or less, more preferably 6 m / s or less, and even more preferably 3 m / s or less, from the viewpoint of promoting deformation of the dispersed phase.

[0031] The length over which the multiphase fluid flows within the third velocity range is preferably 3 mm or more, more preferably 5 mm or more, and even more preferably 8 mm or more, from the viewpoint of suppressing pressure loss during dispersed phase deformation. The length over which the multiphase fluid flows within the third velocity range is preferably 1,000 mm or less, more preferably 500 mm or less, and even more preferably 100 mm or less, from the viewpoint of making the piping compact and improving the maneuverability of the equipment.

[0032] The first ratio is preferably 5 or more, more preferably 10 or more, and even more preferably 20 or more, from the viewpoint of further enhancing the effect of the tensile force on the dispersed phase by the rapidly contracting flow. From the viewpoint of keeping pressure loss low, the first ratio is preferably 1,000 or less, more preferably 500 or less, and even more preferably 200 or less.

[0033] It is preferable to consider a second ratio. Here, when a point (P') set in the constricted passage is moved along the flow direction of the multiphase fluid, the downstream point (P') where the second reference ratio is 5 or more is defined as the second reference point (P2). The second reference ratio is the flow velocity V at the first reference point (P1). (P1) The flow velocity V at point (P') relative to this. (P') The ratio (V (P') / V (P1) In this embodiment, location (P') corresponds to the second candidate point. The second ratio is the ratio of the flow velocity at a point located 15 mm downstream of the second reference point (P2) (P2+15 mm) to the flow velocity at the second reference point (P2) (flow velocity at point (P2+15 mm) / flow velocity at the second reference point (P2)). Furthermore, using the reference point (P1') described in the explanation of the specific ratio above as the reference point, the downstream point where the second flow velocity is five times the flow velocity at the reference point (P1') (i.e., the first ratio becomes 5) is defined as the outlet of the constricted flow passage, which is the second reference point (P2). In this case, the second ratio is the ratio of the flow velocity at the second reference point (P2) to the flow velocity in the downstream piping located at a point (P2+15mm) 15mm downstream of the second reference point (P2) (flow velocity at point (P2+15mm) / flow velocity at the second reference point (P2)). As described above, the reference point (P1') when the specific ratio is 5 or more coincides with the first reference point (P1) described above. Therefore, the second ratio calculated based on the reference point (P1') coincides with the second ratio calculated based on the first reference point (P1). The second ratio is preferably 0.2 or less, more preferably 0.1 or less, and even more preferably 0.05 or less, from the viewpoint of making the effect of the tensile force on the dispersed phase more effective by rapidly reducing the flow velocity. From the viewpoint of keeping pressure loss low, the second ratio is preferably 0.001 or higher, more preferably 0.002 or higher, and even more preferably 0.005 or higher.

[0034] The numerical range of the second ratio mentioned above may also apply to the relationship between the second reference point (P2) and a point upstream of the aforementioned point (P2+15mm). For example, the flow velocity ratio may be 0.2 or less at a point 10mm downstream from the second reference point (P2) and at a point 5mm downstream from the second reference point (P2). This means that the rapid deceleration of the flow velocity occurs over a shorter distance in the flow channel closer to the outlet of the constricted passage. This allows for a more effective reduction of flow turbulence and pressure loss, resulting in a better dispersion state of the dispersion liquid, and enabling the aforementioned tensile force to act more efficiently and effectively.

[0035] It is preferable to consider a third ratio, a fourth ratio, and / or a fifth ratio. The third ratio is the ratio of the flow velocity at the inlet of the constricted passage to the flow velocity at point (P3) (flow velocity at the inlet / flow velocity at point (P3)). Point (P3) is the location of the upstream piping, which is 10 mm upstream from the inlet of the constricted passage. For example, it is "P3" shown in Figures 2(A)~(C) and Figures 3(A)~(C). The third ratio is preferably 5 or more, more preferably 10 or more, and even more preferably 20 or more, from the viewpoint of further enhancing the effect of the tensile force on the dispersed phase due to the rapid contraction flow. From the viewpoint of keeping pressure loss low, the third ratio is preferably 1,000 or less, more preferably 500 or less, and even more preferably 200 or less. The fourth ratio is the ratio of the flow velocity at the inlet of the constricted passage (P4+8mm) to the flow velocity at point (P4) (flow velocity at the inlet / flow velocity at point (P4)). Point (P4) is the location of the upstream piping, which is 8mm upstream from the inlet of the constricted passage. From the viewpoint of further enhancing the effect of the tensile force on the dispersed phase due to the rapid contraction flow, the fourth ratio is preferably 5 or more, more preferably 10 or more, and even more preferably 20 or more. From the viewpoint of keeping pressure loss low, the fourth ratio is preferably 1,000 or less, more preferably 500 or less, and even more preferably 200 or less. The fifth ratio is the ratio of the flow velocity at the inlet of the constricted passage (P5+6mm) to the flow velocity at point (P5) (flow velocity at the inlet / flow velocity at point (P5)). Point (P5) is the location of the upstream piping, which is 6mm upstream from the inlet of the constricted passage. The fifth ratio is preferably 5 or more, more preferably 10 or more, and even more preferably 20 or more, from the viewpoint of further enhancing the effect of the tensile force on the dispersed phase by the rapidly contracting flow. From the viewpoint of keeping pressure loss low, the fifth ratio is preferably 1,000 or less, more preferably 500 or less, and even more preferably 200 or less. This allows for a more effective reduction in pressure loss and enables the application of the aforementioned tensile force to the multiphase fluid. This flow velocity configuration first assumes that the ratio of the flow velocities (second flow velocity / first flow velocity) is 5 or greater, in relation to the first reference point (P1) of the upstream piping and the flow inlet (P1+15mm) of the constricted passage. In addition, this configuration also shows that the relationship holds true even if the reference point is a point P3, P4, or P5 that is closer to the flow inlet (P1+15mm) of the constricted passage than the first reference point (P1) of the upstream piping. Note that (P1+15mm), (P3+10mm), (P4+8mm), and (P5+6mm) all refer to the inlet of the same constricted flow passage. In this embodiment, points P3, P4, and P5 correspond to the third, fourth, and fifth reference points, respectively.

[0036] The pressure on the multiphase fluid in the upstream piping is preferably greater than 0 MPa, more preferably 0.05 MPa or higher, and even more preferably 0.1 MPa or higher, from the viewpoint of effectively generating the tensile force. From the viewpoint of reducing the load on the equipment, the pressure on the multiphase fluid in the upstream piping is preferably 10 MPa or less, more preferably 5 MPa or less, and even more preferably 1 MPa or less. In practice, the pressure on the multiphase fluid in the downstream piping is greater than 0 MPa. From the viewpoint of reducing the load on the equipment, the pressure on the multiphase fluid in the downstream piping is preferably 5 MPa or less, more preferably 2 MPa or less, and even more preferably 0.5 MPa or less. The difference between the pressure on the multiphase fluid in the upstream piping and the pressure on the multiphase fluid in the downstream piping (pressure loss between the upstream and downstream piping) is preferably 10 MPa or less, more preferably 5 MPa or less, and even more preferably 1 MPa or less, from the viewpoint of enabling processing at lower energy. From the viewpoint of applying sufficient tensile force, the difference between the pressure on the multiphase fluid in the upstream piping and the pressure on the multiphase fluid in the downstream piping is practically 0 or greater, preferably 0.05 MPa or greater, more preferably 0.1 MPa or greater, and even more preferably 0.2 MPa or greater.

[0037] (Method for measuring pressure) For the upstream piping, the pressure is measured using a Bourdon tube pressure gauge at a point before the upstream piping (for example, any point within 30 mm upstream from the inlet of the upstream piping). For the downstream piping, the pressure is measured using the pressure gauge at a location near the downstream side of the downstream piping (for example, any location within 30 mm downstream from the flow outlet of the downstream piping).

[0038] As mentioned above, the flow rate of the multiphase fluid is preferably 100 L / hour or more, more preferably 500 L / hour or more, and even more preferably 800 L / hour or more, which is difficult to achieve with conventional dispersion techniques. In practice, the flow rate is preferably 100,000 L / hour or less, more preferably 50,000 L / hour or less, and even more preferably 20,000 L / hour.

[0039] The flow rate of the multiphase fluid can be measured by the same method as the (liquid flow rate) shown in the (method for measuring flow velocity) described above.

[0040] In the velocity distribution of the second flow velocity in the flow direction of the constricted passage, it is preferable that the flow velocity at the inlet of the passage is the smallest. The velocity distribution in the flow direction of the constricted passage may be maintained constant at the flow velocity at the inlet of the passage, or it may increase from the flow velocity at the inlet of the passage as it progresses in the flow direction. This allows the tensile force to be exerted more effectively in the flow field of the constricted passage over a specific length, thereby causing the multiphase fluid to deform and split more smoothly.

[0041] (Method for measuring the velocity distribution of the second flow velocity in a constricted flow passage) The flow rate of the multiphase fluid is divided by the cross-sectional area calculated from the diameter at each point in the constricted passage to calculate the flow velocity at each point in the constricted passage. This gives the velocity distribution of the second flow velocity in the constricted passage.

[0042] In the method for producing a dispersion of the present invention, it is preferable that the upstream piping, the constricting passage, and the downstream piping are connected in series. In other words, it is preferable that the flow pipe extends in a straight line, or that the flow direction of the multiphase fluid is straight. This reduces the rotation and shear of the multiphase fluid, making the effects of the flow field described above more effective. From a similar viewpoint, it is preferable to keep the outer diameter of the flow pipe, in which the upstream piping, the constricting passage, and the downstream piping are connected in series, constant. In addition, it is preferable to configure the aforementioned constricting passage by making the internal flow paths connected in a straight line and changing the flow path diameter.

[0043] There may be no intervening members that change the direction of the multiphase fluid flow at the boundaries between the upstream piping, the constricted passage, and the downstream piping. Also, there may be no obstructions to the flow in the upstream piping and the downstream piping. In that case, the diameter of the flow path may be reduced or increased at each boundary. This makes it possible to minimize (e.g., avoid) the stagnation, rotation, and / or collision of the dispersed phase when the multiphase fluid is flowed from the upstream piping to the constricted passage. Furthermore, in each embodiment of this disclosure, the tensile force due to the aforementioned flow velocity difference can be increased more strongly in the constricted passage, allowing the dispersed phase of the multiphase fluid to be sufficiently deformed and split. In addition, when the multiphase fluid is flowed from the constricted passage to the downstream piping, the flow can be regulated over the formed fine dispersion to suppress pressure loss and maintain a good dispersion state of the dispersion. For example, in terms of the arrangement of each flow path, the spaces of each flow path may be connected such that a straight line can be drawn from the inlet and outlet of the constricted flow path toward the flow path of the upstream piping and the flow path of the downstream piping, following the aforementioned series direction. Preferably, this straight line can be drawn parallel to the flow direction of the multiphase fluid. In this case, the flow path of the constricted flow path may extend linearly along the aforementioned series direction (= flow direction of the multiphase fluid). Furthermore, the flow path cross-sectional area of ​​the constricted flow path may be constant or may vary. In the latter case, the flow path cross-sectional area of ​​the constricted flow path may decrease along the flow direction (for example, gradually or in steps), and multiple decreasing forms (for example, the two forms described above) can be combined. In these various configurations, as described above, in the velocity distribution of the second flow velocity in the flow direction of the constricted flow passage, the flow velocity at the inlet of the flow passage may be the smallest.

[0044] In the method for producing a dispersion liquid of the present invention, a specific example of a stationary dispersion apparatus including a flow pipe having the upstream piping, the constriction passage, and the downstream piping is shown in Figures 5 to 7. The stationary dispersion device 10 shown in Figure 5 includes a flow pipe 4 having an upstream pipe 1, a constricted flow passage 21, and a downstream pipe 3 along the flow direction of the multiphase fluid. The upstream pipe 1, the constricting passage 21, and the downstream pipe 3 are connected in series along the flow direction Y of the multiphase fluid. The spaces of each passage 1A, 21A, and 3A are connected such that a straight line can be drawn from the inlet 211 and outlet 212 of the constricting passage 21 toward the passage 1A of the upstream pipe 1 and the passage 3A of the downstream pipe 3, respectively, along the direction of the series connection. Furthermore, the passage 21A of the constricting passage 21 extends linearly along the direction of the series connection (= the flow direction Y of the multiphase fluid). For example, as shown in the figure, there are no members interposed at the boundaries between each passage that change the direction of the multiphase fluid flow. This configuration allows for smoother flow, reduced pressure loss, effective exertion of the tensile force, and maintenance of a better dispersion state of the dispersion. The stationary distribution device 20 shown in Figure 6 differs from the stationary distribution device 10 shown in Figure 5 in the configuration of the constricted flow passage 21. The constricted flow passage 21 in the stationary distribution device 20 has a first constricted flow passage 213 and a second constricted flow passage 214 adjacent to the downstream side of the first constricted flow passage 213. The flow path cross-sectional area of ​​the second constricted flow passage 214 is smaller than the flow path cross-sectional area of ​​the first constricted flow passage 213. As a result, the flow path cross-sectional area of ​​the constricted flow passage 21 decreases in a stepped manner from the flow path inlet 211 to the flow path outlet 212. In addition, the upstream piping 1 is provided with a constricted flow introduction passage 22 in the portion adjacent to the constricted flow passage 21. The constricted flow introduction passage 22 has a flow path 22A with a cross-sectional area larger than the flow path cross-sectional area of ​​the constricted flow passage 21 and smaller than the maximum flow path cross-sectional area of ​​the upstream piping 1. For example, the constricted flow introduction passage 22 can be defined as a region where the flow velocity is accelerated more than the first flow velocity and lower than the second flow velocity. In the flow-contraction introduction passage 22, the ratio of the flow velocity in the flow-contraction introduction passage 22 to the flow velocity at the first reference point (P1) described above (flow velocity in the flow-contraction introduction passage 22 / flow velocity at the first reference point (P1)) is less than 5. This configuration allows for a smooth flow and suppression of pressure loss, while simultaneously providing the appropriate energy necessary for droplet deformation and splitting, thereby maintaining a good dispersion state in the dispersion. The stationary dispersion device 30 shown in Figure 7 differs from the stationary dispersion device 20 shown in Figure 6 in the manner of reducing the flow channel cross-sectional area of ​​the flow constriction introduction passage 22 and flow constriction passage 21. In the stationary dispersion device 30, the flow channel cross-sectional area is reduced (for example, gradually) from the flow constriction introduction passage 22 to the flow channel inlet 211 and flow channel outlet 212 of the flow constriction passage 21. This configuration allows for smoother flow, reduced pressure loss, and maintenance of a better dispersion state in the dispersion.

[0045] In these specific examples, it is preferable that the constricted passage 21 is a portion where the ratio (B / A) of the flow path cross-sectional area B of the constricted passage 21 to the maximum flow path cross-sectional area A of the upstream pipe 1 is within a certain range. From the viewpoint of more favorably forming the aforementioned difference in flow velocity, the ratio (B / A) is preferably 0.001 or more and 0.2 or less, more preferably 0.002 or more and 0.1 or less, and even more preferably 0.005 or more and 0.05 or less. The "maximum flow path cross-sectional area A" refers to the flow path cross-sectional area of ​​the portion of the upstream piping where the flow path diameter is largest, within the flow direction of the multiphase fluid.

[0046] In the method for producing a dispersion of the present invention, the flow of the multiphase fluid can be divided into two or more parts in the orthogonal plane direction through the constricted flow passage. Here, dividing the flow of the multiphase fluid into two or more parts means dividing the flow of the multiphase fluid into two or more separate flows of the multiphase fluid. This increases the processing volume of the multiphase fluid in a single pass, thereby further improving the productivity of the dispersion. A concrete example of this is shown in Figure 8. In the stationary distribution device 40 shown in Figure 8, three flow paths 21A of the constriction passage 21 are arranged in parallel in the orthogonal plane direction X. In this case, for each flow path 21A, the spaces of each flow path 1A, 21A, and 3A are connected such that a straight line can be drawn from the flow path inlet 211 and flow path outlet 212 toward the flow path 1A of the upstream pipe 1 and the flow path 3A of the downstream pipe 3 along the flow direction Y of the multiphase fluid (= the direction in which the upstream pipe 1, the constriction passage 21, and the downstream pipe 3 are connected in series). The flow paths 21A of the constriction passage 21 extend linearly along the flow direction Y. For example, in Figure 8, one constriction passage 21 is composed of three flow paths 21A. In this case, the above ratio (B / A) is calculated for each of the three flow paths 21A. The number of flow channels 21A in the constricted flow passage 21 is not limited to those shown in Figure 8, but can be set as appropriate.

[0047] In the configuration where the constricted flow passage has two or more flow paths in the orthogonal plane direction, the value obtained by dividing the number of flow paths in the constricted flow passage by the maximum flow path cross-sectional area A of the upstream piping is 0.01 paths / cm 2 Preferably, it should be 0.02 strands / cm 2 It is more preferable that the value be greater than or equal to 0.04 strands / cm 2 It is even more preferable that the above conditions be met. This allows for an increase in processing capacity. Furthermore, if the above value is 8 lines / cm 2 The following is preferable: 5 strands / cm 2 More preferably, it is 3 strands / cm 2 The following is even more preferable. This makes it possible to maintain a stronger tensile force due to the difference in flow velocity.

[0048] In the method for producing the dispersion of the present invention, the stationary dispersion apparatus used is not limited to the above-described examples. Various forms of apparatus can be used that can effectively produce an action specialized for mixing under tensile force by implementing the above-described combination of specific flow velocities and specific flow lengths in the upstream piping, the constricted flow passage, and the downstream piping. For example, this could include the specific examples shown in Figures 9(A)-(C), 10(A)-(D), 11, and 12(A)-(C).

[0049] Figures 9(A)-(C) and 10(A)-(D) show the inflow angle at the inlet of the constricted flow passage, and it is preferable that the inflow angle is between 60 degrees and 90 degrees. This allows the multiphase fluid to be rapidly introduced into the constricted flow passage, thereby increasing the velocity difference and applying a stronger tensile force to the dispersed phase. When the flow-constricting passage is located adjacent to the upstream piping, the inflow angle is the angle (outer angle) formed on the flow-constricting side of the upstream piping, which is the intersection angle between the flow-constricting wall surface of the flow-constricting passage and the outer wall surface of the flow-constricting passage facing the flow-constricting passage of the upstream piping. If there is a flow-constricting introduction passage between the flow-constricting passage and the upstream piping, the inflow angle is one of the following: One is the angle of intersection between the flow channel wall surface of the flow channel of the flow-constricting passage and the flow channel wall surface of the flow channel of the flow-constricting introduction passage, which is the angle (outer angle) formed on the flow channel side of the upstream piping. The other is the angle of intersection between the flow channel wall surface of the flow channel of the flow-constricting passage and the outer wall surface of the flow-constricting passage facing the flow channel of the flow-constricting introduction passage, which is the angle (outer angle) formed on the flow channel side of the upstream piping.

[0050] In the stationary dispersion device 50A shown in Figure 9(A), a configuration is shown in which there is a step in the flow path between the flow path 21A of the constricted flow passage 21 and the flow path 1A of the upstream pipe 1. The cross-sectional area of ​​the flow path 21A of the constricted flow passage 21 is kept constant along the flow direction Y. In this configuration, the outer angle θ (the outer angle formed on the upstream pipe 1 side) of the angle formed between the flow path wall surface 21W of the constricted flow passage 21 and the outer wall surface 21E of the constricted flow passage 21 facing the flow path 1A of the upstream pipe 1 can be defined as the inflow angle. In the stationary distribution device 50B shown in Figure 9(B), there is a flow-constriction introduction passage 22 upstream of the flow-constriction passage 21. The flow path cross-sectional area of ​​the flow path 22A of the flow-constriction introduction passage 22 gradually decreases toward the flow path 21A of the flow-constriction passage 21. The flow path cross-sectional area of ​​the flow path 21A of the flow-constriction passage 21 is kept constant along the flow direction Y. In this configuration, the outside angle θ of the angle formed by the flow path wall surface 21W of the flow-constriction passage 21 and the flow path wall surface 22W of the flow-constriction introduction passage 22 can be defined as the inflow angle. In other words, the inflow angle θ is defined by the angle formed by the imaginary line L1 with respect to the flow path wall surface 22W of the flow-constriction introduction passage 22. The imaginary line L1 is a line connecting the center of the flow path cross-section at the flow path inlet 211 of the flow-constriction passage 21 and the center of the flow path cross-section at the flow path outlet 212. The stationary distribution device 50B also has a flow-constriction release passage 23 connected to the downstream piping 3 downstream of the flow-constriction passage 21. The flow path 23A of the flow-constriction release passage 23 increases (for example, gradually) toward the flow path 3A of the downstream pipe 3. Thus, in the flow-constriction passage 21 shown in Figure 9B, the flow path cross-sectional area of ​​the portion adjacent to the flow-constriction introduction passage 22 can be made smaller along the flow direction Y, the flow path cross-sectional area of ​​the flow path 21A can be kept constant along the flow direction Y, and the flow path cross-sectional area of ​​the portion adjacent to the flow-constriction release passage 23 can be made larger along the flow direction Y. In the stationary dispersion device 50C shown in Figure 9(C), a configuration is shown in which the cross-sectional area of ​​the flow path 21A of the constricted flow passage 21 can be reduced in a stepped manner. Upstream of this, there is a constricted flow introduction passage 22, and the cross-sectional area of ​​its flow path 22A is made larger than the cross-sectional area of ​​the flow path 21A of the constricted flow passage 21. In this configuration, the outer angle θ of the angle formed between the flow path wall surface 21W on the upstream side of the constricted flow passage 21 and the outer wall surface 21E of the constricted flow passage 21 facing the flow path 22A of the constricted flow introduction passage 22 can be defined as the inflow angle. In the stationary dispersion device 60A shown in Figure 10(A), a configuration is shown in which the cross-sectional area of ​​the flow path 21A of the constricted flow passage 21 can be gradually reduced along the flow direction Y. In this configuration, the outer angle θ of the angle formed by the flow path wall surface 21W and the outer wall surface 21E near the flow path inlet 211 of the constricted flow passage 21 can be defined as the inflow angle. In the stationary dispersion device 60B shown in Figure 10(B), a configuration is shown in which the cross-sectional area of ​​the flow path 21A of the constricted flow passage 21 can be gradually expanded along the flow direction Y. In this configuration, the outer angle θ of the angle formed by the flow path wall surface 21W and the outer wall surface 21E near the flow path inlet 211 of the constricted flow passage 21 can be defined as the inflow angle. In the stationary dispersion device 60C shown in Figure 10(C), the extension direction of the flow path 21A of the constricted flow passage 21 is inclined with respect to the extension direction of the flow path 1A of the upstream piping 1. In this configuration, the outer angle θ of the angle formed by the flow path wall surface 21W and the outer wall surface 21E near the flow path inlet 211 of the constricted flow passage 21 can be defined as the inflow angle. In the stationary dispersion device 60D shown in Figure 10(D), the extension direction of the flow path 21A of the constricted flow passage 21 is curved relative to the extension direction of the flow path 1A of the upstream piping 1. In this configuration, the outer angle θ of the angle formed by the flow path wall surface 21W and the outer wall surface 21E near the flow path inlet 211 of the constricted flow passage 21 can be defined as the inflow angle.

[0051] At the inlet of the flow-constricting passage, the intersecting portion of the wall surface constituting the inlet may be chamfered. Alternatively, curvature may be provided at the intersecting portion of the wall surface constituting the inlet. For example, in the stationary distribution device 50A shown in Figure 11, the intersection portion 21X of the flow channel wall surface 21W of the constricted flow channel 21 and the outer wall surface 21E of the constricted flow channel 21 facing the flow channel 1A of the upstream piping 1 is chamfered. For example, in a cross section along the imaginary line L1, if the distance from the intersection point of the extensions of the flow channel wall surface 21W and the outer wall surface 21E to the wall surface of the intersection portion 21X is 1 mm or less, it is considered to be chamfered. In this case, the inflow angle is the outer angle θ of the angle at which the extensions of the flow channel wall surface 21W and the outer wall surface 21E intersect. This chamfer may also be present at the intersection portion of the wall surfaces constituting the flow channel inlet in Figures 9(B) and (C) and Figures 10(A) to (C). This allows the multiphase fluid to be drawn more smoothly into the constricted flow passage, making it easier to apply a stronger tensile force. From this perspective, the chamfer dimension R1 of the chamfer provided at the intersection of the wall surfaces constituting the flow channel inlet may be greater than 0 mm and less than or equal to 1.0 mm, preferably less than or equal to 0.8 mm, and more preferably less than or equal to 0.5 mm. The chamfer dimension R1 can be the distance between the intersection of the flow channel wall surface 21W and the outer wall surface 21E, respectively, in a cross section along the imaginary line L1, and the endpoint of the flow channel wall surface 21W (or outer wall surface 21E) connected to the intersection portion 21X. Alternatively, the radius of curvature R2 of the intersection of the wall surfaces constituting the flow channel inlet may be greater than 0 mm and less than or equal to 1.0 mm, preferably less than or equal to 0.8 mm, and more preferably less than or equal to 0.5 mm. The radius of curvature R2 can be the radius of the curved surface that becomes the intersection portion 21X in a cross section along the imaginary line L1.

[0052] The aforementioned constriction passages may be arranged in two or more locations in the flow direction. In this configuration, by arranging two or more constriction passages in the flow direction of the multiphase fluid, the tensile force can be applied two or more times in a single flow. As a result, a finer dispersion can be formed. For example, one configuration is one in which the first constricting passage, the intermediate pipe, and the second constricting passage are arranged in this order along the flow direction. In this configuration, the distance between the outlet of the first constricting passage and the inlet of the second constricting passage is preferably more than 3 mm, more preferably 5 mm or more, and even more preferably 8 mm or more. By ensuring a sufficient distance between the constricting passages, the flow velocity accelerated in the upstream first constricting passage is temporarily reduced in the intermediate pipe, and the tensile force based on the flow velocity difference in the subsequent second constricting passage can be more effectively and strongly increased. From the viewpoint of miniaturizing the stationary dispersion apparatus used in the method for producing the dispersion liquid of the present invention and facilitating the handling of the apparatus, the aforementioned separation distance is preferably 100 mm or less, more preferably 80 mm or less, and even more preferably 50 mm or less. In the case of the two or more flow-constricting passages, it is preferable that the centers of the flow channels in the cross-section of the flow channels coincide on a straight line from the inlet of the upstream flow-constricting passage to the outlet of the downstream flow-constricting passage. In other words, the two or more flow channels that constitute the flow-constricting passages are configured such that the centers of the flow channels in the cross-section of each flow channel pass through a single straight line. This stabilizes the flow state. Here, "coinciding on a straight line" means the following: For example, consider a plane parallel to the flow direction of the multiphase fluid and perpendicular to a virtual line passing through the center of the first constriction passage. Here, a circular region is defined from the center of the first constriction passage, having an area greater than 0% but less than or equal to 10%, preferably less than or equal to 5%, of the flow area of ​​the first constriction passage. When viewed along the flow direction of the multiphase fluid, the projection of the center of the second constriction passage on the direction of the virtual line is included in that circular region. The configuration of the "first constriction passage, intermediate piping, and second constriction passage" may consist of one set or two or more sets in the flow direction. If there are two or more sets, it is preferable to interpose the intermediate piping between each set. Furthermore, the configuration of the "first constriction passage, intermediate piping, and second constriction passage" may consist of one set or two or more sets in the orthogonal plane direction. For example, there may be two or more sets of the "first constriction passage, intermediate piping, and second constriction passage," and these sets can be arranged parallel to each other so as to extend along the direction from the upstream side to the downstream side of each mixing pipe.

[0053] Specific examples of the above are shown in Figures 12(A) to (C). In the stationary dispersion device 70A shown in Figure 12(A), the first constriction passage 21U, intermediate pipe 5, and second constriction passage 21D are arranged in this order along the flow direction Y. The distance M between the flow outlet 212U of the first constriction passage 21U and the flow inlet 211D of the second constriction passage 21D can be greater than 3 mm when measured along the flow direction of the multiphase fluid. The first constriction passage 21U and the second constriction passage 21D have the same flow diameter. The centers of the flow paths in the cross-section of the flow paths lie on a virtual line L1 from the respective flow inlets 211U and 211D to the flow outlets 212U and 212D, and coincide on a straight line. The intermediate pipe 5 has the same flow path cross-sectional area as the upstream pipe 1 and the downstream pipe 3. In this configuration, the distance M corresponds to the flow path length of the intermediate pipe 5 in the flow direction Y. The stationary dispersion apparatus 70B shown in Figure 12(B) differs from the configuration in Figure 12(A) in that the flow diameter of the second constriction passage 21D is smaller than the flow diameter of the first constriction passage 21U. In this configuration, the flow diameter of the downstream constriction passage 21D is smaller than the flow diameter of the upstream constriction passage 21U. This makes it possible to deform the droplets of the dispersed phase in the constriction passage 21U and split the droplets in the constriction passage 21D, thereby obtaining a better dispersion more efficiently. The stationary dispersion apparatus 70C shown in Figure 12(C) differs from the configuration in Figure 12(B) in that the height position of the flow path of the second constriction passage 21D is different from the height position of the flow path of the first constriction passage 21U. In other words, the centers of the flow path cross-sections of the first constriction passage 21U and the second constriction passage 21D are offset in the direction of the orthogonal plane. In this configuration, the difference in the height positions of the two constriction passages 21U and 21D makes it possible to slightly change the linearity of the liquid flow, thereby promoting the exchange of positions of the dispersion liquid and obtaining a better dispersion liquid.

[0054] It is preferable that when two or more of the constricted flow passages are arranged in the flow direction and the flow path cross-sections of each of the constricted flow passages are projected in the flow direction and superimposed, 90% to 100%, preferably 95% or more, and more preferably 100%, of the area of ​​the flow path cross-section of the downstream constricted flow passage is included in the region of the flow path cross-section of the upstream constricted flow passage. This configuration means that when two or more of the constricted flow passages are arranged along the flow direction, the flow path of the constricted flow passage is made smaller as one moves downstream. Furthermore, the flow path inlet of the downstream constricted flow passage is made to be linearly connected to the flow path outlet of the upstream constricted flow passage. This makes it possible to create a smooth flow of the multiphase fluid. And as the flow path diameter decreases, the flow velocity difference with respect to the dispersed phase of the multiphase fluid can be made progressively stronger. In other words, the increase in the tensile force can be made larger. Specific examples of this are shown in Figures 12(A) to (C). In all configurations, when projected and superimposed in the flow direction, the flow channel cross-section of the downstream second constriction passage 21D is included in the region of the flow channel cross-section of the upstream first constriction passage 21U.

[0055] In the method for producing a dispersion of the present invention, a stationary dispersion device including a flow pipe having an upstream pipe, a constricting passage, and a downstream pipe may be used independently or in connection with other devices such as piping. In the latter case, for example, the supply process of a (for example, fine) dispersion can be completed by introducing the stationary dispersion device into the flow of piping or the like. As described above, in one or more embodiments relating to this disclosure, the upstream piping may have an upstream opening on its upstream side that connects to piping from a multiphase fluid supply source. This allows for the continuous flow of the multiphase fluid. The downstream piping may have a downstream opening on its downstream side that connects to piping for transferring the multiphase fluid to other processes. This allows the formed fine dispersion to be supplied to the necessary processes without delay. At the downstream opening of the downstream piping, another pipe may be switchably arranged to return the multiphase fluid to the upstream opening of the upstream piping. This allows the multiphase fluid to be circulated the required number of times. The number of circulations can be varied depending on the degree of deformation and splitting of the dispersed phase due to the tensile force, and can be predetermined by the physical properties of the multiphase fluid (e.g., viscosity) and the required particle size of the dispersed phase. The number of circulations can be controlled by flow rate and time.

[0056] In the method for producing a dispersion of the present invention, it is preferable to circulate the multiphase fluid as described above, passing it through the upstream piping, the constricted flow passage, and the downstream piping two or more times. This makes it possible to perform the dispersion treatment of the multiphase fluid mildly at low pressure, and to control the particle size distribution more accurately and effectively.

[0057] Next, preferred forms of the method for producing the dispersion of the present invention when the dispersed phase is a liquid, and preferred forms when the dispersed phase is a solid will be described.

[0058] (1) When the dispersed phase is a liquid (1-1) The continuous phase preferably has a viscosity of 0.1 mPa·s or more, more preferably 0.3 mPa·s or more, and even more preferably 0.5 mPa·s or more at 25°C. This makes it easier to impart stress to the dispersion and makes it easier for the dispersion to flow in a laminar state, thus making it easier to obtain a finer dispersion. The viscosity of the continuous phase is preferably 50,000 mPa·s or less, more preferably 5,000 mPa·s or less, and even more preferably 500 mPa·s or less. This facilitates pumping and reduces the energy required.

[0059] (Method for measuring viscosity) Using a Type B viscometer (TVB10 viscometer, manufactured by Toki Sangyo Co., Ltd.), the viscosity of each phase is measured at 25°C, a rotation speed of 60 rpm, and a measurement time of 1 minute. For viscosities up to 10 mPa·s, the TML adapter is used. For viscosities up to 100 mPa·s, the TM1 rotor is used, and for viscosities up to 2,000 mPa·s, the TM3 rotor is used. For viscosities of 10,000 mPa·s, the TM4 rotor is used. When measuring liquids with higher viscosities, the measurement is performed using the TM4 rotor at a rotation speed of 6 rpm and a measurement time of 1 minute. When measuring viscosity based on a multiphase fluid, the continuous phase and dispersed phase are separated using a centrifuge, and the above measurements are performed on each phase. Since the conditions for the centrifuge vary depending on the raw materials, the centrifugal force and time required to separate each dispersion are set accordingly. This viscosity measurement method conforms to the ISO 2555 standard (Apparent viscosity measurement using a rotational viscometer).

[0060] (1-2) The dispersed phase preferably contains a compound with low solubility in the continuous phase. In reality, the solubility is 0 ppm or higher. The solubility is preferably 1,000 ppm or less, more preferably 100 ppm or less, and even more preferably 1 ppm or less. This creates an interface between the continuous phase and the dispersed phase, enabling mixing as droplets. The solubility mentioned above is the soluble mass of the compound per 100 g of the continuous phase in an environment of 25°C and 65% relative humidity (RH), and is a value measured based on the measurement method described later. The dissolution of the compound refers to the phenomenon in which the compound dissolves in the continuous phase and becomes liquid, and does not include cases of emulsification (where the dispersed phase is dispersed as droplets) or suspension (where the dispersed phase is dispersed as solid fine particles).

[0061] (Method for measuring solubility) In an environment of 25°C and 65% relative humidity (RH), 1 mg of the compound is added to 1 L of solvent used in the continuous phase, and the mixture is stirred for 1 hour. Visual confirmation is then performed to determine whether it dissolves. When visually confirming, the boundary between the solvent and the compound is determined to determine whether it dissolves or not. If it dissolves, the same procedure is repeated with 10 times the amount of compound added each time, up to a total of 1,000 mg.

[0062] (1-3) Preferably, one of the continuous phase and the dispersed phase contains water, and the other of the continuous phase and the dispersed phase contains oil. That is, it is preferable that the resulting dispersion is an emulsion. This makes it possible to mix substances with different properties and exhibit various effects.

[0063] (1-4) Preferably, the dispersed phase has a mass ratio of 1% or more to 70% or less of the multiphase fluid. When the liquid dispersed phase has a mass ratio of 1% or more than the lower limit, the dispersed phase can exert its effect as a dispersion or emulsion. When the liquid dispersed phase has a mass ratio of 1% or less than the upper limit, the dispersed phase can be stably maintained. From the above viewpoint, the mass ratio is preferably 1% or more, more preferably 5% or more, and even more preferably 10% or more. From the above viewpoint, the mass ratio is preferably 70% or less, more preferably 65% ​​or less, and even more preferably 50% or less.

[0064] (1-5) It is preferable that the multiphase fluid contains a surfactant. The mass percentage of the surfactant contained in the multiphase fluid is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more. This makes it possible to further break down the liquid of the dispersed phase into smaller particles, thereby improving the stability when it becomes a dispersion or emulsion. The mass percentage of the surfactant contained in the multiphase fluid is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1.5% by mass or less. This reduces irritation when the product is used on the skin, improves affinity to the skin, and enhances safety and quality by allowing the dispersion to perform to its full potential. The mass percentage representing the mass percentage of the surfactant is the surfactant content based on the total weight of the multiphase fluid. That is, the mass percentage of the surfactant is the ratio of the weight of the surfactant contained in a predetermined amount of multiphase fluid to the total weight of a predetermined amount of multiphase fluid (weight of surfactant contained in a predetermined amount of multiphase fluid / total weight of a predetermined amount of multiphase fluid). Specific examples of the surfactant may include one or more selected from cationic surfactants, anionic surfactants, nonionic surfactants, and amphoteric surfactants.

[0065] In the method for producing a dispersion of the present invention, when the dispersed phase is a liquid, the number of times it is circulated through the upstream piping, the constricted flow passage, and the downstream piping (number of circulations, number of passes) can be determined according to the ratio of the viscosity of the dispersed phase to the viscosity of the continuous phase (viscosity of the dispersed phase / viscosity of the continuous phase). In this regard, in the method for producing a dispersion of the present invention, the viscosity ratio and the number of passes tend to be inversely proportional. That is, the larger the viscosity ratio, the fewer passes are needed to reach the target diameter of the dispersed phase (e.g., the emulsion diameter). On the other hand, the smaller the viscosity ratio, the more passes are needed to reach the target diameter of the dispersed phase. In this case, it is preferable to appropriately set the flow velocity within the aforementioned range of flow velocities for the upstream piping, the constricted flow passage, and the downstream piping according to the viscosity ratio. Thus, in the method for producing the dispersion of the present invention, it is preferable to determine an appropriate number of passes according to the viscosity ratio. This makes it possible to split the dispersed phase with less energy and higher efficiency, and to produce a finer dispersion more effectively.

[0066] (1-6) In the method for producing a dispersion of the present invention, from the viewpoint of making it easier to produce a finer dispersion with fewer passes (e.g., one pass) of the mixed fluid of the dispersed phase and the continuous phase of (1-1), the viscosity of the liquid contained in the dispersed phase at 25°C is preferably 10 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 1,000 mPa·s or more, and particularly preferably 5,000 mPa·s or more. From the viewpoint of suppressing pressure loss and facilitating the preparation of the dispersion with low energy, the viscosity of the liquid contained in the dispersed phase at 25°C is preferably 100,000 mPa·s or less, more preferably 80,000 mPa·s or less, and even more preferably 50,000 mPa·s or less.

[0067] (1-7) In the embodiments of (1-6) above, from the viewpoint of making it easier to produce a finer dispersion with fewer flow cycles (e.g., one cycle), the viscosity ratio of the liquid contained in the dispersed phase to the continuous phase is preferably 10 or more, more preferably 200 or more, and even more preferably 300 or more. In the above embodiments (1-6), from the viewpoint of further suppressing pressure loss and processing the dispersion liquid with less adhesion to the piping, the viscosity ratio of the liquid contained in the dispersed phase to the continuous phase is preferably 1,000,000 or less, more preferably 500,000 or less, and even more preferably 50,000 or less.

[0068] (1-8) From the viewpoint of making it easier to produce a finer dispersion by increasing the number of circulation cycles to two or more, the viscosity of the liquid contained in the dispersed phase at 25°C is preferably 0.1 mPa·s or more, more preferably 0.5 mPa·s or more, and even more preferably 1 mPa·s or more. From the viewpoint of enabling the preparation of the dispersion with lower pressure loss by passing the liquid through two or more times, the viscosity of the liquid contained in the dispersed phase at 25°C is preferably 50,000 mPa·s or less, more preferably 30,000 mPa·s or less, and even more preferably 15,000 mPa·s or less.

[0069] (1-9) In the embodiments of (1-8) above, from the viewpoint of being able to produce a finer dispersion more effectively, the viscosity ratio of the liquid contained in the dispersed phase to the continuous phase is preferably 0.000002 or higher, more preferably 0.0002 or higher, and even more preferably 0.2 or higher. In the above configurations (1-8), from the viewpoint of further suppressing pressure loss and minimizing adhesion to the piping while processing the dispersion, the viscosity ratio of the liquid contained in the dispersed phase to the continuous phase is preferably 500,000 or less, more preferably 250,000 or less, and even more preferably 300 or less. The above upper limit also includes cases where the flow cycle is two or more times, even in a high viscosity ratio range, from the viewpoint of ensuring product uniformity and stability.

[0070] (1-10) It is preferable that the diameter of the dispersed phase in the dispersion is greater than 0 μm and less than or equal to 100 μm. This diameter has technical significance in that it further improves the stability of the emulsion compared to conventional methods. According to the method for producing the dispersion of the present invention, the dispersed phase can be split with low energy and high efficiency, so that a finer dispersion in which the liquid dispersed phase has the aforementioned diameter can be produced with high productivity. From this viewpoint, the diameter of the dispersed phase in the dispersion is more preferably 70 μm or less, and even more preferably 40 μm or less. The diameter of the dispersed phase in the dispersion refers to the number-average particle diameter obtained by the measurement method described below.

[0071] (Method for measuring the diameter of the dispersed phase in the dispersion) The inflection coefficients of the dispersed phase and continuous phase are investigated during measurement using laser diffraction (a measurement method using the LA-950 V2 (product name) manufactured by Horiba, Ltd.), and the measurement is performed based on the investigated values. Both circulation control and stirring control are set to 5 out of 10 levels, and ultrasonic dispersion is not used. A histogram is created with the particle size of the dispersed phase in the dispersion liquid plotted on the x-axis and frequency on the y-axis. The number-average particle size in the histogram is taken as the emulsion particle size of each sample. This method for measuring emulsion particle size conforms to the standards of ISO 13320 and JIS Z8825.

[0072] (2) When the dispersed phase is a solid (2-1) In the method for producing the dispersion of the present invention, from the viewpoint of enabling disintegration by wet disintegration, the particle size of the aggregated particles (secondary particles) contained in the solid before dispersion is preferably 0.1 μm or larger, more preferably 0.5 μm or larger, and even more preferably 1 μm or larger. The term "before dispersion" as used above refers to the state before carrying out the method for producing the dispersion of the present invention. From the viewpoint of making it easier to improve the dispersion stability of the particles, the particle size of the aggregated particles is preferably 1,000 μm or less, more preferably 800 μm or less, and even more preferably 500 μm or less.

[0073] (2-2) In the embodiment of (2-1) above, from the viewpoint of making it easier to express the properties of the solid in the continuous phase, the content of the dispersed phase in the multiphase fluid based on the total weight of the multiphase fluid is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 10% by mass or more. In the embodiment described in (2-1) above, from the viewpoint of ensuring that the entire dispersion behaves as a liquid, the content of the dispersed phase in the multiphase fluid based on the total weight of the multiphase fluid is preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 50% by mass or less. The content of the dispersed phase described above is the ratio of the weight of the dispersed phase contained in a predetermined amount of multiphase fluid to the total weight of a predetermined amount of multiphase fluid (weight of the dispersed phase contained in a predetermined amount of multiphase fluid / total weight of a predetermined amount of multiphase fluid).

[0074] (2-3) The diameter of the dispersed phase in the dispersion is preferably greater than 0 μm and less than or equal to 500 μm, more preferably less than or equal to 100 μm, and even more preferably less than or equal to 50 μm. Here, the dispersed phase refers to primary particles or finely divided secondary particles. Primary particles are the smallest independent particle units, which do not split further chemically or crystallographically even when subjected to mechanical separation operations, for example. Secondary particles are aggregates of primary particles. Such a diameter of the dispersed phase has technical significance in that the surface area is larger than in conventional methods, and the solid properties are made more pronounced. According to the method for producing the dispersion of the present invention, the dispersed phase can be split with low energy and high efficiency. As a result, a finer dispersion can be produced with high productivity.

[0075] (Method for measuring the diameter of aggregated particles contained in the solid before dispersion and the diameter of the dispersed phase in the dispersion) If the average particle diameter exceeds 100 nm, the diameter of the aggregated particles is measured using the laser diffraction method described above (a measurement method using the LA-950 V2 (product name) manufactured by Horiba, Ltd.). This method for measuring the emulsion particle diameter conforms to the standards of ISO 13320 and JIS Z 8825. If the average particle diameter is 100 nm or less, a histogram is created using the dynamic light scattering method (a measurement method using the SZ-100 (product name) manufactured by Horiba, Ltd.), with the particle size of the aggregated particles in the multiphase fluid on the x-axis and the frequency on the y-axis. During measurement, the refractive index of the liquid being dispersed and the refractive index of the solid being measured are investigated and input. The particle size at which the cumulative frequency in the histogram reaches 50% is defined as the diameter of the aggregated particles in the multiphase fluid (median diameter).

[0076] In the method for producing the dispersion of the present invention, the following combinations of continuous phase and dispersed phase are preferred: (A) and (B). (A) One of the continuous phase and the dispersed phase contains water. The other of the continuous phase and the dispersed phase contains one or more selected from silicone oil, fluorine oil, ester oil, hydrocarbon oil, higher alcohol, and ether oil.

[0077] (B) The continuous phase comprises one or more selected from water, silicone oil, fluorine oil, ester oil, hydrocarbon oil, higher alcohol, and ether oil. The dispersed phase comprises one or more selected from pigment, catalyst, ultraviolet scattering agent, and fiber.

[0078] The dispersions of the continuous phase and the dispersed phase specified in (A) and (B) above are preferably cosmetics, hair dyes, and detergents. [Examples]

[0079] The present invention will be described in more detail below based on examples, but the present invention is not to be interpreted as being limited thereto. In these examples, "parts" and "%" are both based on mass unless otherwise specified. "-" means that there is no corresponding value for that item. In Tables 1 to 4, the first flow velocity is the "flow velocity at the first reference point (P1)", the second flow velocity is the "maximum flow velocity in the constricted passage", and the third flow velocity is the "flow velocity at a position 15 mm downstream of the second reference point (P2), which is the outlet of the constricted passage (P2+15 mm)".

[0080] (Example 1) (i) Preparation of multiphase fluid: A mixture of 20% by mass of silicone oil (dispersed phase; viscosity 10,000 mPa·s at 25°C, manufactured by Shin-Etsu Chemical Co., Ltd., product name KF-96-10000CS) and 79% by mass of water (continuous phase) was used. To this, 1% by mass of surfactant (manufactured by Kao Corporation, product name Cortamin 60W) was added to prepare a multiphase fluid sample. (ii) Method for producing the dispersion: The stationary dispersion device 10 shown in Figure 5 was modified to meet the conditions shown in Table 1 and incorporated into the circulating mixer shown in Figure 13. The output of the pump 91 was controlled by an inverter to achieve the flow rate shown in Table 1, and the multiphase fluid was delivered at the flow rate, flow rate, and number of passes (circulations) shown in Table 1, thereby carrying out the method for producing the dispersion liquid of Example 1. (iii) Measurement of "Flow Rate of Multiphase Fluid" in Table 1: At the time before processing, only the continuous phase (fluid) was circulated. Then, at the circulation outlet where the fluid is poured from the piping into the tank 92 (the flow path outlet of the downstream piping 3 of the static dispersion device 10), the fluid was collected for 10 seconds and its volume was measured. Based on this, the flow rate per hour was calculated. (iv) Measurement of "flow velocity" in Table 1: Based on the volume of fluid collected and measured over the aforementioned 10 seconds, the flow rate per hour was calculated as shown in the (Method for Measuring Flow Velocity) section above. Using this flow rate, the first, second, and third flow velocities were calculated based on the formulas shown in the (Method for Measuring Flow Velocity) section above. Regarding the "applied pressure" (pressure on the multiphase fluid in the upstream piping), a pressure gauge 93 was installed before the upstream piping, and its reading was recorded as the pressure.

[0081] (Example 2) Except for the "flow channel diameter of the constricted flow passage," the "number of flow channels arranged in parallel in the orthogonal plane direction in the constricted flow passage," and the "applied pressure," the method for producing the dispersion of Example 2 was carried out in the same manner as in Example 1. As a result, the first, second, and third flow velocities, the "flow rate of the multiphase fluid," and the "ratio of the first to fifth" were different from those of Example 1, as shown in Table 1.

[0082] (Example 3) The method for producing the dispersion of Example 3 was carried out in the same manner as in Example 1, except that the "continuous length in the flow direction that maintains the second flow velocity of the constricted passage" and the "applied pressure" were as shown in Table 1.

[0083] (Example 4) Except for the "flow channel diameter of the constricted flow passage," the "number of flow channels arranged in parallel in the orthogonal plane direction in the constricted flow passage," and the "applied pressure," the method for producing the dispersion liquid of Example 4 was carried out in the same manner as in Example 1.

[0084] (Examples 5 and 6) The methods for producing the dispersions of Examples 5 and 6 were carried out in the same manner as in Example 1, except that the "continuous length in the flow direction that maintains the second flow velocity of the constricted passage" was as shown in Table 1.

[0085] (Example 7) The method for producing the dispersion of Example 7 was carried out in the same manner as in Example 2, except that silicone oil (viscosity 10 mPa·s at 25°C, manufactured by Shin-Etsu Chemical Co., Ltd., product name KF-96-10CS) was used as the dispersion phase and the "applied pressure" was as shown in Table 1.

[0086] (Example 8) A mixed oil of a model fragrance and tetraethoxysilane (viscosity 5 mPa·s at 25°C) was used as the dispersed phase, and multiphase fluid samples were prepared in the proportions shown in Table 2. Cortamine 60W (manufactured by Kao Corporation, (product name)) was used as the surfactant. The specific component composition was as follows. <Model fragrance> mass% Methyldihydrojasmonate 20.6 γ-decalactone 13.5 Ethylene brushlate 12.0 ot-Butylcyclohexyl acetate 11.0 Ambercore 8.0 Other 34.9 <Multiphase fluid sample> mass% Continuous phase (aqueous phase) Deionized water 59.6 Dispersed phase (oil phase) Model fragrance 31.9 Tetraethoxysilane 8.0 Surfactant Cortamin 60W 0.5 The stationary dispersion device 10 shown in Figure 5 was modified to meet the conditions shown in Table 2 and incorporated into the circulating mixer shown in Figure 13. The output of the pump 91 was controlled by an inverter to achieve the flow rate shown in Table 2, and the multiphase fluid was delivered at the flow rate, flow rate, and number of passes (circulation cycles; 5 times) shown in Table 2, and the method for producing the dispersion liquid of Example 8 was carried out.

[0087] (Example 9) As shown in Table 2, the method for producing the dispersion liquid of Example 9 was carried out in the same manner as in Example 8, except that the continuous phase and the dispersed phase were pre-mixed upstream of the upstream piping, the applied pressure was increased, and the number of passes (flow cycles) was reduced to one. As a result, the first, second, and third flow velocities, the flow rate of the multiphase fluid, and the ratios from the first to the fifth were different from those of Example 8, as shown in Table 2.

[0088] (Example 10) (i) The dispersed phase was prepared as follows: Specifically, a 7% cellulose solution (viscosity 100 mPa·s at 25°C, using Ceolus PH-101 (product name) manufactured by Asahi Kasei Corporation as the raw material cellulose) was used. 100 g of 8% sodium hydroxide aqueous solution was added to 81.4 g of deionized water. Then, 18.6 g of cellulose powder was added and stirred with a spatula to obtain a cellulose dispersion. The obtained cellulose dispersion was then cooled to -2°C using a cooling water circulation device (set temperature -5°C). Next, 50 g of a 22% sodium hydroxide aqueous solution at -15°C was added to the cooled cellulose dispersion. The cellulose was dissolved to obtain a cellulose aqueous solution. The obtained aqueous solution had a cellulose concentration of 7.0% by mass and a sodium hydroxide (NaOH) concentration of 7.6% by mass. This was used as the dispersed phase. (ii) Preparation of multiphase fluids Isododecane (viscosity 0.8 mPa·s at 25°C) was used as the continuous phase, and a multiphase fluid sample was prepared together with the dispersed phase in the proportions shown in Table 2. Ryoto sugar ester ER-290 (manufactured by Mitsubishi Chemical Corporation, (trade name)) was used as the surfactant. The specific component composition was as follows. <Multiphase fluid> mass% Continuous phase (oil phase) Isododecane 59.94 Dispersed phase (aqueous phase): Cellulose 2.80 Sodium hydroxide 3.04 Deionized water 34.16 Surfactant: Ryoto Sugar Ester ER-290 0.06 (iii) The stationary dispersion device 10 shown in Figure 5 was modified to the conditions shown in Table 2 and incorporated into the circulating mixer shown in Figure 13. The output of the pump 91 was controlled by an inverter to achieve the flow rate shown in Table 2, and the multiphase fluid was delivered at the flow rate, flow rate, and number of passes (circulation times; 10 times) shown in Table 2, and the method for producing the dispersion liquid of Example 10 was carried out.

[0089] (Example 11) Ethylhexyl methoxycinnamate (viscosity 40,000 mPa·s at 25°C, manufactured by BASF Japan Ltd., trade name Ubinal MC80) was used as the dispersed phase, a 0.4% solution of (acrylates / alkyl (C10-30)) crosspolymer (viscosity 100 mPa·s at 25°C, manufactured by Lubrizol Corporation, trade name Pemulen TR-1 Polymer) was used as the continuous phase, and sorbitan distearate (Sunsoft No. 63C, trade name, manufactured by Taiyo Kagaku Co., Ltd.) was used as the surfactant. The continuous phase and the dispersed phase were pre-mixed upstream of the upstream piping in the proportions shown in Table 2 to prepare a multiphase fluid sample. The specific component composition was as follows. <Multiphase fluid> mass% Continuous phase (aqueous phase) (Acrylates / C10-30 alkyl acrylate) crosspolymer 0.4 Deionized water 76.0 Potassium hydroxide (48%) 0.2 Dispersed phase (oil phase): Ethylhexyl methoxycinnamate 11.8 Ethanol 11.2 Surfactant: Sorbitan distearate 0.4 The stationary dispersion device 10 shown in Figure 5 was modified to meet the conditions shown in Table 2 and incorporated into the circulating mixer shown in Figure 13. The output of the pump 91 was controlled by an inverter to achieve the flow rate shown in Table 2, and the multiphase fluid was delivered at the flow rate, flow rate, and number of passes (circulation times; 2) shown in Table 2, thereby carrying out the method for producing the dispersion liquid of Example 11.

[0090] (Example 12) The method for producing the dispersion of Example 12 was carried out in the same manner as in Example 11, except that the number of passes (circulations) was reduced to one.

[0091] (Examples 13 and 14) Using the stationary dispersion device 50B shown in Figure 9(B), the method for producing the dispersion was carried out in the same manner as in Example 1, except that the inlet angle was set to 60° in Example 13 and to 45° in Example 14. Note that "Change observed" in "Change in flow velocity related to the constricted flow passage" in Table 2 means that the flow velocity changes in accordance with the flow of the multiphase fluid from the flow path 22A of the constricted flow introduction passage 22 to the flow path 21A of the constricted flow passage 22 and the flow path 23A of the constricted flow release passage 23. In the flow velocity distribution of the second flow velocity in the flow direction of the constricted flow passage, the flow velocity at the flow channel inlet 211 was the smallest.

[0092] (Example 15) A multiphase fluid sample was prepared using titanium dioxide (solid, particle size 100 nm before dispersion, manufactured by Teika Corporation, product name MT-100TV) as the dispersed phase, glyceryl tricaprylate (viscosity 100 mPa·s at 25°C, manufactured by Kao Corporation, product name Coconard MT) as the continuous phase, and polyhydroxystearic acid (manufactured by Nisshin Oillio Group Ltd., product name Saracos HS-6C) as the surfactant, in the proportions shown in Table 3. The stationary dispersion device 10 shown in Figure 5 was modified to meet the conditions shown in Table 1 and incorporated into the circulating mixer shown in Figure 13. The output of the pump 91 was controlled by an inverter to achieve the flow rate shown in Table 3, and the multiphase fluid was delivered at the flow rate, flow rate, and number of passes (circulation cycles; 10 times) shown in Table 3, thereby carrying out the method for producing the dispersion liquid of Example 15.

[0093] (Comparative Example 1) As shown in Table 4, the method for producing the dispersion of Comparative Example 1 was carried out in the same manner as in Example 1, except that the "continuous length in the flow direction that maintains the second flow velocity of the constricted passage" was set to 3 mm.

[0094] (Comparative Example 2) As shown in Table 4, the dispersion manufacturing method of Comparative Example 2 was carried out by increasing the "flow channel diameter of the constricted flow passage," reducing the "applied pressure," and lowering the "second flow velocity" to less than 5 m / sec, compared to the conditions in Example 1. As a result, the "first ratio" to the "fifth ratio" are as shown in Table 4.

[0095] (Comparative Example 3) As shown in Table 4, the continuous phase and the dispersed phase used in Example 1 were pre-mixed upstream of the upstream piping. Of the conditions in Example 1, the flow path diameters of the upstream piping, the constricted passage, and the downstream piping were reduced, the "continuous length in the flow direction that maintains the second flow velocity of the constricted passage" was extended to 10 times that of Example 1, and the "first flow velocity" was set to over 10 m / sec, the "second flow velocity" to over 110 m / sec, and the "third flow velocity" to over 10 m / sec so that the "flow rate of the multiphase fluid" was the same as in Example 1 (14.4 L / min), and the method for producing the dispersion liquid of Comparative Example 3 was carried out. However, this required applying very high pressure. As a result, the output from the pump was unstable, the flow rate and flow velocity could not be sufficiently obtained, and the dispersion liquid was not formed. For this reason, "---" is indicated for "obtained emulsion particle diameter (average diameter)" and "applied pressure" in Table 4.

[0096] (Comparative Example 4) As shown in Table 4, the dispersion manufacturing method of Comparative Example 4 was carried out by installing flow-obstructing plates so that the "continuous length in the flow direction that maintains the third flow velocity in the downstream piping" in the conditions of Example 1 was less than 3 mm. In addition, as shown in Table 4, the "flow channel diameter of the constricted passage" in the conditions of Example 1 was increased. As a result, the "second flow velocity" decreased, and the "first ratio" to the "fifth ratio" became as shown in Table 4.

[0097] (Comparative Example 5) A static dispersion apparatus sample was prepared using the static dispersion apparatus 70A shown in Figure 12(A) under the conditions shown in Table 4. In this case, the separation distance M between the flow outlet 212U of the first constriction passage 21U and the flow inlet 211D of the second constriction passage 21D was set to 2 mm. The "continuous length in the flow direction that maintains the second flow velocity of the constriction passage" was set to less than 5 mm. The dispersion manufacturing method of Comparative Example 5 was carried out using the static dispersion apparatus sample described above. The two values ​​shown in the columns for "Second flow velocity" and "Continuous length in the flow direction that maintains the second flow velocity of the constricted passage" in Table 4 are the values ​​for the first constricted passage 21U and the second constricted passage 21D, respectively. The values ​​shown in the column for "Change in flow velocity related to the constricted passage" in Table 4 indicate that the velocity changes in this order for the first constricted passage 21U, the intermediate pipe 5, and the second constricted passage 21D, respectively. The values ​​shown in the column for "Number of flow channels arranged in parallel in the orthogonal plane direction in the constricted passage" in Table 4 are the values ​​for the first constricted passage 21U and the second constricted passage 21D, respectively.

[0098] (Comparative Example 6) In Comparative Example 6, a stationary dispersion apparatus sample was prepared under the conditions shown in Table 4, in accordance with the apparatus described in Example 1 of Patent Document 1 and Figure 1(a) of Patent Document 1. In the stationary dispersion apparatus sample of Comparative Example 6, two plate-like bodies (a first plate-like body and a second plate-like body) with different numbers of through-holes constituting the constriction passage related to this disclosure were used. Each through-hole was the same shape and size. The through-holes had the following shape: The largest circular openings were formed on the upstream surface and downstream back surface of the plate-like body, at relative positions. In addition, a minimum opening with the smallest through-hole area was formed midway along the thickness direction of the plate. From the surface and back openings, a series of gradually decreasing diameter openings were arranged towards the minimum opening. The first plate-like body contained five through-holes (constriction passages), with the other four through-holes arranged adjacently in a cross shape around one through-hole. The second plate-like body contained four through-holes (constriction passages), with each through-hole arranged adjacently in a square grid pattern. The first and second plate-like bodies were positioned such that the central through-hole of the first plate-like body and the center of the square formed by the four through-holes of the second plate-like body passed through the same straight line extending in the direction of the multiphase fluid flow. In Comparative Example 6, the values ​​shown in the items related to the constricted flow passage in Table 4 were for a combination of 10 alternating first and second plate-like bodies, offset so that the centers of the flow passages in the cross-section of the flow passage did not coincide on a straight line. The first plate-like body had a flow passage diameter of 1.5 mm, a continuous length of 1 mm in the flow direction at the second flow velocity, and 5 flow passages. The second plate-like body had a flow passage diameter of 1.5 mm, a continuous length of 1 mm in the flow direction at the second flow velocity, and 4 flow passages. The continuous length of each plate-like body in the flow direction at the second flow velocity was less than 5 mm. The method for producing the dispersion of Comparative Example 6 was carried out using the static dispersion apparatus sample described above. The 10 values ​​shown in the columns for "Constricted flow passage: Second flow velocity," "Continuous length in the flow direction at the second flow velocity of the constricted flow passage," "Number of constricted flow passages arranged in parallel in the orthogonal plane direction in the constricted flow passage," and "First ratio" to "Fifth ratio" in Table 4 are values ​​for the first plate-like body and the second plate-like body, which are combined in alternating pairs of 10 pieces. "Change observed" in the column for "Change in flow velocity related to the constricted flow passage" in Table 4 means that the flow velocity changes in accordance with the flow of the multiphase fluid through the flow path, which is made up of 10 alternating pairs of the first plate-like body and the second plate-like body. In the static dispersion apparatus sample described above, the "upstream piping: first flow velocity" shown in Table 4 refers to the upstream piping of a unit in which 10 plates of the first and second plate-like bodies are alternately combined, and the "downstream piping: third flow velocity" refers to the downstream piping of the unit.

[0099] (test) (1) Measurement of emulsion particle size The size of the emulsified particles was measured during one circulation cycle and after ten circulation cycles. During the first and tenth cycles of distribution, samples were taken after the dispersion and mixing process at the circulation outlet, and the emulsified particle size was measured. The smaller the emulsified particle size, the faster the emulsification rate, indicating that a finer dispersion was formed. (2) Pressure applied A lower "applied pressure" indicates that the dispersed phase could be split with less energy. Lower pressure also indicates that a fine dispersion could be formed with less energy, higher efficiency, and greater productivity.

[0100] [Table 1]

[0101] [Table 2]

[0102] [Table 3]

[0103] [Table 4]

[0104] As shown in Tables 1 and 4, Examples 1, 3-6 were able to reduce the emulsion particle size compared to Comparative Examples 1-5, which used the same dispersed phase. Furthermore, Example 2 achieved an emulsion particle size comparable to Examples 1, 3-6 even under reduced pressure conditions, and was able to form an even smaller emulsion particle size compared to Comparative Example 2, which also had reduced pressure. Furthermore, when the emulsion particle size change was observed after more than 10 passes for Example 7 and Comparative Example 6, as shown in Figure 14, the emulsion particle size in Example 7 was smaller from the initial dispersion treatment compared to Comparative Example 6. No matter how many times it was circulated, the emulsion particle size in Example 7 remained smaller than that of Comparative Example 6, forming a finer dispersion system. In Example 7, the applied pressure was lower than that of Comparative Example 6, achieving a smaller emulsion particle size with lower energy. In other words, in Example 7, compared to Comparative Example 6, lower energy (lower pressure), less pressure loss, a faster emulsification rate, and a smaller final emulsion diameter were achieved with lower energy (lower pressure). Thus, in the method for producing a dispersion of the present invention, by combining a first flow velocity, a second flow velocity, the length for maintaining the second flow velocity, a third flow velocity, and the length for maintaining the third flow velocity within a specific range, it has been found that in one or more embodiments of this disclosure, it is possible to form an effective flow field with low pressure loss, thereby producing a fine dispersion with low energy, high efficiency, and high productivity, and that this method can be put into use and / or implemented. In Comparative Example 3, as mentioned above, when attempting to make the flow rate equivalent to that of Example 1, the pressure was too high, resulting in unstable pump output and the inability to obtain a dispersion.

[0105] As shown in Tables 2 and 3, it was found that the above effects can be achieved even if the viscosity, viscosity ratio (dispersed phase / continuous phase), and properties of the dispersed phase differ, and even if the inflow angle of the multiphase fluid differs. Furthermore, in Examples 8 and 9 shown in Table 2, the "viscosity ratio (dispersed phase / continuous phase)" was set to "5," which is lower than in Example 1. The "number of passes (circulation)" was set to "5 times" (circulation) in Example 8 and to "1 time" in Example 9. At low viscosity ratios, circulation resulted in smaller emulsion particle sizes than a single pass. In other words, at low viscosity ratios, increasing the number of passes (circulation) allowed for the production of finer dispersions. On the other hand, in Examples 11 and 12 shown in Table 2, the "viscosity ratio (dispersed phase / continuous phase)" was set to "400," which is higher than the above. The "number of passes (circulation)" was set to "2 times" (circulation) in Example 11 and "1 time" in Example 12. At high viscosity ratios, nearly the same emulsion particle size was obtained between Example 11 and Example 12 even when the number of passes (circulation) was reduced from 2 times to 1 time. In other words, at high viscosity ratios, a dispersion effect equivalent to circulation was obtained with just one pass, and a fine dispersion could be produced with low energy, high efficiency, and good productivity.

[0106] Although the present invention has been described with reference to its embodiments and examples, we do not intend to limit our invention in any detail of the description unless specifically designated, and we believe that it should be interpreted broadly without contradicting the spirit and scope of the invention as set forth in the appended claims. [Explanation of Symbols]

[0107] 1. Upstream piping 21 Contraction passage 3 Downstream piping 4 Flow pipe 10, 20, 30, 40, 50A~50C, 60A~60D, 70A~70C stationary dispersion device

Claims

1. A method for producing a dispersion, The multiphase fluid is flowed in the following order: first into the first pipe at the first flow velocity, then into the constricted passage at the second flow velocity, and finally into the second pipe at the third flow velocity. The first flow velocity is between 0.02 m / s and 10 m / s. In the aforementioned constricted passage, the multiphase fluid is flowed at the second flow velocity for 5 mm or more. The second flow velocity is, Faster than the first flow velocity, The flow velocity along the aforementioned constricted flow passage is such that it changes or remains constant within a range of 5 m / s to 110 m / s. The first ratio is 5 or more, The first ratio is the ratio of the second flow velocity to the flow velocity at the first reference point (second flow velocity / flow velocity at the first reference point), The first reference point is the first candidate point furthest upstream when the first candidate point set in the first piping is moved along the flow direction of the multiphase fluid, such that the first reference ratio is 5 or more. The first reference ratio is the ratio of the flow velocity at a point located 15 mm downstream of the first candidate point to the flow velocity at the first candidate point (flow velocity at the point located 15 mm downstream of the first candidate point / flow velocity at the first candidate point). In the second piping, the multiphase fluid is flowed at a third flow velocity of 3 mm or more. The third flow velocity is 10 m / s or less. The aforementioned multiphase fluid is obtained by mixing a liquid continuous phase with one or more dispersed phases selected from other liquids, solids, and gases. A method for producing a dispersion.

2. The second ratio is between 0.001 and 0.2, The second ratio is the ratio of the flow velocity at a point located 15 mm downstream of the second reference point to the flow velocity at the second reference point (flow velocity at the point located 15 mm downstream of the second reference point / flow velocity at the second reference point). The second reference point is the second candidate point furthest downstream when the second candidate point set within the constricted flow passage is moved along the flow direction of the multiphase fluid, such that the second reference ratio is 5 or more. The method for producing a dispersion according to claim 1, wherein the second reference ratio is the ratio of the flow velocity at the second candidate point to the flow velocity at the first reference point (flow velocity at the second candidate point / flow velocity at the first reference point).

3. The third ratio is 5 or greater, The point located 15 mm downstream from the first reference point is the inlet of the flow channel of the constricted passage. The method for producing a dispersion according to claim 1 or 2, wherein the third ratio is the ratio of the second flow velocity at the inlet of the flow path to the flow velocity at a third reference point of the first piping located 10 mm upstream from the inlet of the flow path of the constricted flow passage.

4. A method for producing a dispersion according to claim 1 or 2, wherein the pressure on the multiphase fluid in the first piping is greater than 0 MPa and 10 MPa or less.

5. A method for producing a dispersion according to claim 1 or 2, wherein the flow rate of the multiphase fluid is 100 L / hour or more and 100,000 L / hour or less.

6. The method for producing a dispersion according to claim 1 or 2, wherein the first flow velocity is 0.1 m / s or more and 6 m / s or less.

7. The method for producing a dispersion according to claim 1 or 2, wherein the second flow velocity is a flow velocity that changes or remains constant within a range of 10 m / s to 95 m / s.

8. The method for producing a dispersion according to claim 7, wherein the length for maintaining the second flow velocity is 5 mm or more and 100 mm or less.

9. The method for producing a dispersion according to claim 1 or 2, wherein the third flow velocity is 0.02 m / s or more and 10 m / s or less.

10. The method for producing a dispersion according to claim 9, wherein the length for maintaining the third flow velocity is 3 mm or more and 1,000 mm or less.

11. The method for producing a dispersion according to claim 1 or 2, wherein the continuous phase has a viscosity at 25°C of 0.1 mPa·s or more and 50,000 mPa·s or less, and the dispersed phase contains a liquid.

12. A method for producing a dispersion according to claim 1 or 2, wherein one of the continuous phase and the dispersed phase contains water, and the other of the continuous phase and the dispersed phase contains oil.

13. A method for producing a dispersion according to claim 1 or 2, wherein the dispersed phase includes a solid, and the solid contains aggregated particles with a particle size of 0.1 μm or more and 1,000 μm or less before dispersion.

Images