WO2017110670A1

WO2017110670A1 - A dispersing system and a process for dispersing

Info

Publication number: WO2017110670A1
Application number: PCT/JP2016/087530
Authority: WO
Inventors: Katsuaki Odagi; Kouji Kajita; Yutaka Hagata; Yuu Ishida
Original assignee: Sintokogio, Ltd.
Priority date: 2015-12-24
Filing date: 2016-12-16
Publication date: 2017-06-29
Also published as: KR20180098126A; CN107708850A; JP2019505374A

Abstract

To provide a dispersing system and a process for dispersing that efficiently carry out a preliminary dispersion to disperse particles to be on a nanometer scale. The dispersing system (100) that disperses a mixture of a slurry comprises a first shear-type dispersing device (1) that causes the mixture (4) to flow between a rotor (2) and a stator (3) that is disposed to face the rotor (2) toward an outer circumference by centrifugal force to disperse the mixture (4), and a second dispersing device (60) that makes solid particles finer to be on a nanometer scale in the mixture (4) that has been dispersed by means of the first dispersing device (1).

Description

A DISPERSING SYSTEM AND A PROCESS FOR DISPERSING

The present invention relates to a dispersing system and a process for dispersing that disperses substances in a mixture of a slurry.

Conventionally, when a dispersing device, such as a bead mill, a jet mill, or a high-pressure-type homogenizer (a nozzle-type dispersing device), is used for dispersing particles to be on a nanometer scale, especially particles that contain large agglomerated particles of some tens to some hundreds of micrometers in size, the efficiency in dispersion decreases. This is because the agglomerated particles cannot be dispersed, the dispersing device is clogged, and so on. These are problems.

In this situation, the particles are preliminarily dispersed before being dispersed to be on a nanometer scale. That is, solid particles are dispersed to become particles of some tens of micrometers or less in size. However, if an agitating-type dispersing device is used, the power to disperse the particles is weak. Further, an uneven dispersion may occur. If a conventional disc-type dispersing device is used, the gap between the discs is some hundreds of micrometers, and thereby the particles cannot be dispersed to a size that is smaller than the gap. Thus, none of these conventional dispersing devices sufficiently improve the efficiency of an entire dispersing system.

The purpose of the present invention is to provide a dispersing system and a process for dispersing that efficiently carries out a preliminary dispersion to disperse particles to be on a nanometer scale.

A dispersing system of a first aspect of the present invention that disperses a mixture of a slurry comprises, as in Fig. 1, for example, a first shear-type dispersing device 1 that causes the mixture 4 to flow between a rotor 2 and a stator 3 that is disposed to face the rotor 2 toward the outer circumference by centrifugal force to disperse it. The dispersing system 1 also comprises a second dispersing device 60 that makes solid particles finer to be on a nanometer scale in the mixture 4 that has been dispersed by means of the first dispersing device 1.

By this configuration large agglomerated particles that are contained in the mixture are made to become smaller particles without uneven dispersion by the first shear-type dispersing device. The particles are efficiently made finer to be on a nanometer scale by the second dispersing device. The term “disperse” used herein means to make powdery substances in a slurry finer and make them be uniformly distributed.

By the dispersing system of a second aspect of the present invention that disperses the mixture of a slurry, as in Figs. 1 and 3, for example, in the dispersing system of the first aspect the first dispersing device 1 has a container 11 for receiving the mixture 4 that has passed between the rotor 2 and stator 3, a cover assembly 12 for closing an upper opening 11a of the container 11, the stator 3 that is fixed to a bottom of the cover assembly 12, the rotor 2 that is disposed to face the lower face of the stator 3, and a rotary shaft 13 that rotates the rotor 2. The gap between the rotor 2 and the stator 3 is 10 micrometers or larger, and 1,000 micrometers or smaller. By this configuration, since the gap between the rotor 2 and the stator 3 is 10 micrometers or larger, and 1,000 micrometers or smaller, the agglomerated particles in the mixture are dispersed without uneven dispersion, to become smaller particles by means of the first shear-type dispersing device.

By the dispersing system of a third aspect of the present invention that disperses the mixture of a slurry, in the dispersing system of the second aspect the second dispersing device 60 is any of a bead mill, a jet mill, and a high-pressure-type homogenizer. By this configuration, a general-purpose bead mill, jet mill, or high-pressure-type homogenizer is used as the second dispersing device, so as to efficiently disperse particles to be on a nanometer scale.

By the dispersing system of a fourth aspect of the present invention that disperses the mixture of the slurry, in the dispersing system of any of the first to third aspects, the mean diameter of the solid particles in the mixture before being dispersed by the first dispersing device 1 is 1 micrometer or greater, and 1,000 micrometers or smaller, and the mean diameter of the solid particles in the mixture after being dispersed by the second dispersing device 60 is less than 1 micrometer. Since the particles are dispersed by the first shear-type dispersing device so that they become smaller particles without uneven dispersion and these particles are dispersed by the second dispersing device to be on a nanometer scale, the mixture that contains solid particles of which the mean diameter is 1 micrometer or greater, and 1,000 micrometers or smaller, can be efficiently dispersed to become a mixture that contains solid particles of which the mean diameter is less than 1 micrometer.

By the dispersing system of a fifth aspect of the present invention that disperses the mixture of a slurry, in the dispersing system of any of the first to third aspects, the mixture to be dispersed by the dispersing system 1 is a mixture of one or more powdery materials that are selected from a group of carbon black, a carbon nanotube, a grapheme, an inorganic powder, and a powder made of a metal or a metal oxide and one or more liquid materials that are selected from a group of water, a solvent, and a resin. Since the powdery material and the liquid material are dispersed to be on a nanometer scale, a useful mixture can be obtained.

The dispersing system of a sixth aspect of the present invention that disperses the mixture of a slurry, as in Fig. 1, for example, in the dispersing system of the fourth aspect, further comprises a rough-dispersing device 110 that disperses the mixture 4 that is to be supplied to the first dispersing device 1. The rough-dispersing device 110 mixes together a powdery material P and a liquid material L, both of which are the raw materials of the mixture 4. Since the mixture is obtained by mixing together the powdery material and the liquid material, and since the mixture is dispersed by a shearing force by means of the first dispersing device and then is dispersed to be on a nanometer scale by the second dispersing device, the dispersing system can efficiently make the solid particles finer, to be on a nanometer scale.

By the dispersing system of a seventh aspect of the present invention that disperses the mixture of a slurry, as in Figs. 1 and 2 for example, in the dispersing system of the sixth aspect the rough-dispersing device 110 has any of a turbine-type impeller 114, a dispersing-type impeller 115, a propeller-type impeller 116, and an anchor-type impeller 113. By this configuration the rough-dispersing device can have a simple structure.

The dispersing system of an eighth aspect of the present invention that disperses the mixture of a slurry, in the dispersing system of the sixth aspect, further comprises a third dispersing device that causes the mixture 4 that has been dispersed by means of the rough-dispersing device 110 to flow between a rotor and a stator that is disposed to face the rotor toward the outer circumference by centrifugal force to disperse it to supply the dispersed mixture to the first dispersing device 1. By this configuration, even if large particles are included after the rough dispersion, the particles are definitely dispersed. Thus the dispersing system can efficiently make the solid particles to be on a nanometer scale.

By the dispersing system of a ninth aspect of the present invention that disperses the mixture of a slurry, as in Figs. 1, 3, and 4, for example, in the dispersing system of the second or third aspect the first dispersing device 1 has a bearing 14 that is disposed in the cover assembly 12 and disposed above the stator 3 and that rotatably holds the rotary shaft 13. It also has a spacer 15 that is detachably disposed between the rotary shaft 13 and the rotor 2 and that adjusts a gap between the rotor 2 and the stator 3. When the spacer 15 is disposed, the position of the rotor 2 in relation to the stator 3 in an axial direction is fixed. By this configuration, the gap between the rotor 2 and the stator 3 can be easily adjusted by exchanging the spacer with one that has a different thickness.

By the dispersing system of a tenth aspect of the present invention that disperses the mixture of a slurry, as in Figs. 3 and 4, for example, in the dispersing system of the ninth aspect the cover assembly 12 has a part 17 for holding the bearing that holds the bearing 14 and a part 18 for holding the stator that is provided under the part 17 for holding the bearing and that holds the stator 3. The part 17 for holding the bearing has a part 21 for controlling an axial position that controls the axial position of the part 18 for holding the stator by contacting the part 17 for holding the bearing with the part 18 for holding the stator through a second spacer 20. The second spacer 20 is detachably provided between the part 17 for holding the bearing and the part 18 for holding the stator so as to adjust the axial position of the stator 3 in relation to the part 17 for holding the bearing by being exchanged with one that has a different length. A concave part 22 is formed on the upper surface of the rotor 2 so that the lower end of the rotary shaft 13 is inserted into the concave part 22. A through-hole opens on the concave part 22. The lower end 13a of the rotary shaft 13 is inserted into the concave part 22 of the rotor 2. A fastening member 23 is fixed from a lower surface of the rotor 2 while the lower end 13a abuts the concave part 22 through the spacer 15. The fastening member 23 fastens the rotary shaft 13 to the rotor 2 across the spacer 15 by fixing a part of the fastening member 23 to the rotary shaft 13 through the through-hole of the rotor 2. A plurality of pins 24 are inserted into the concave part 22 of the rotor 2 and the lower end 13a of the rotary shaft 13 to transmit the rotational power of the rotary shaft 13 to the rotor 2. The pins 24 are disposed at uniform intervals along the circumferential direction. A first through-hole 15a, through which the fastening member 23 is inserted, and second through-holes 15b, through which the pins 24 are inserted, are formed in the spacer 15. By this configuration, the axial position of the stator can be adjusted by exchanging the second spacer with one that has a different length. Further, since the lower end of the rotary shaft is inserted into the concave part of the rotor and the rotational power of the rotary shaft is transmitted to the rotor by means of the plurality of pins, the rotational power of the rotor can be definitely obtained.

By the dispersing system of an eleventh aspect of the present invention that disperses the mixture of a slurry, as in Figs. 1, 3, and 4, for example, in the dispersing system of the tenth aspect the stator 3 is bigger than the rotor 2 on the plane where the stator 3 faces the rotor 2. In the stator 3 a groove 26 for cooling is formed on the surface opposite the surface that faces the rotor 2, so that a coolant flows through the groove 26 for cooling. The groove 26 for cooling is located beyond the outer edge of the rotor 2. A wall 27 is formed along a radial direction on the groove 26 for cooling. A port 28 for supplying coolant and a port 29 for discharging the coolant are disposed across the wall 27. The coolant that is supplied from the port 28 for supplying the coolant to the groove 26 flows toward the direction in which no wall 27 is formed near the port 28 for supplying the coolant, in the circumferential direction. The coolant is discharged from the port 29 for discharging the coolant. In the stator 3 a hole 31 for inserting the rotary shaft is formed, through which hole the rotary shaft 13 passes. The mixture 4 is supplied from outside the positions of the hole 31 of the stator 3 to the gap between the stator 3 and the rotor 2. By this configuration, since the stator is definitely cooled by the coolant, generating heat in the mixture can be definitely prevented. Further, the mixture that has been supplied from outside the positions of the hole for inserting the rotary shaft to the gap between the stator and the rotor is caused to flow outwardly by means of centrifugal force without approaching the hole for inserting the rotary shaft, so that no seal is required.

By the dispersing system of a twelfth aspect of the present invention that disperses the mixture of a slurry, as in Figs. 1, 3, and 4, for example, in the dispersing system of the eleventh aspect a through-hole 32 for supplying the mixture 4 is formed outside the hole 31 for inserting the rotary shaft in the stator 3. A port 33 for supplying the mixture, and a passage 34 that communicates with the through-hole 32 for supplying the mixture to the port 33 and is provided in the stator 3, are provided in the part 18 for holding the stator. The mixture 4 that is supplied from the port 33 is introduced to the gap between the stator 3 and the rotor 2 through the passage 34 in the part 18 and the through-hole 32 in the stator 3. A second hole 36 for inserting the rotary shaft, through which the rotary shaft 13 is inserted, is formed in the part 18 for holding the stator. A labyrinth seal 37 is provided to the second hole 36. Air is supplied from outside the part 18 for holding the stator in a space 38 that is located within the part 18 and connected to the upper part of the second hole 36 for inserting the rotary shaft. A cooling mechanism 41 is provided to the container 11. By this configuration, since the mixture is supplied through the port for supplying the mixture in the part for holding the stator, through the passage, and through the through-hole in the stator, it is definitely supplied from the position outside the hole for inserting the rotary shaft of the stator to the gap between the stator and the rotor. Further, since the second hole for inserting the rotary shaft is provided in the part for holding the stator, since the labyrinth seal is provided in the second hole for inserting the rotary shaft, and since air is supplied to the space that is connected to the upper part of the second hole for inserting the rotary shaft, a strong seal can be obtained. Further, since a cooling mechanism is provided, the mixture in the container can be cooled.

By the dispersing system of a thirteenth aspect of the present invention that disperses the mixture of a slurry, as in Fig. 6, for example, in the dispersing system of the twelfth aspect the container 11 has a conical wall 42 wherein the cross section decreases from the top to the bottom. A port 44 for discharging is provided at a lower end of the container 11 to discharge the mixture 4 that has been dispersed. An agitating plate 82a is provided to the container 11 so as to scrape off the mixture 4 of any slurry that adheres to the

wall

42, 43. By this configuration, the discharge of the mixture is facilitated so that the yield is improved.

By the dispersing system of a fourteenth aspect of the present invention that disperses the mixture of a slurry, in the thirteenth aspect the rotor 2 and the stator 3 are made of a stainless steel on which a ceramic is thermal sprayed. By this configuration, the life of the rotor and the stator can be prolonged and any contamination by metal can be prevented.

A process for dispersing of a fifteenth aspect of the present invention that disperses a mixture of a slurry comprises, as in Fig. 1, for example, the step of supplying a mixture 4 to a gap between a rotor 2 and a stator 3 that is disposed to face the rotor 2, of a first dispersing device 1. It also comprises the step of causing the mixture 4 to flow outwardly between the rotor 2 and the stator 3 by means of centrifugal force to disperse the mixture 4 by a shearing force by means of the rotor 2 and the stator 3. It also comprises the step of supplying the mixture that has been dispersed by the first dispersing device 1 to a second dispersing device 60. It also comprises the step of making solid particles, in the mixture 4 that has been supplied to the second dispersing device 60, finer, to be on a nanometer scale, by means of the second dispersing device 60.

By this configuration, large agglomerated particles that are contained in the mixture are dispersed without uneven dispersion, to become small particles by means of the first shear-type dispersing device. The solid particles are efficiently made finer to be on a nanometer scale by means of the second dispersing device.

The present invention will become more fully understood from the detailed description given below. However, the detailed description and the specific embodiments are only illustrations of the desired embodiments of the present invention, and so are given only for an explanation. Various possible changes and modifications will be apparent to those of ordinary skill in the art on the basis of the detailed description.
The applicant has no intention to dedicate to the public any disclosed embodiment. Among the disclosed changes and modifications, those which may not literally fall within the scope of the present claims constitute, therefore, a part of the present invention in the sense of the doctrine of equivalents.
The use of the articles "a," "an," and "the" and similar referents in the specification and claims are to be construed to cover both the singular and the plural form of a noun, unless otherwise indicated herein or clearly contradicted by the context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein is intended merely to better illuminate the invention, and so does not limit the scope of the invention, unless otherwise stated.

Fig. 1 is a schematic drawing of the dispersing system that shows cross sections of some parts. Fig. 2 shows some examples of agitating blades that are suitable to be used in a rough-dispersing device. Figure (a) is a perspective view of disc turbine-type agitating blades. Figure (b) is a perspective view of dissolver-type (dispersing-type) agitating blades. Figure (c) is a perspective view of propeller-type agitating blades. Fig. 3 is a schematic drawing of the first dispersing device. Figure (a) shows a cross section taken along the line A1-A1 in Fig. 4. Figure (b) shows a cross section taken along the line A2-A2 in Fig. 4 and a cross section taken along the line A3-A3 in Fig. 4, but the lower part is omitted. Fig. 4 illustrates the details of the first dispersing device in Fig. 3. Figure (a) shows a cross section taken along the line A4-A4 in Fig. 3. Figure (b) shows a cross section taken along the line A5-A5 in Fig. 3. Figure (c) shows enlarged major parts illustrating a spacer, a labyrinth seal that is located at a second hole for inserting the rotary shaft, and a seal that is sealed by air purging. Figure (d) shows enlarged major parts illustrating a second spacer. Figure (e) shows enlarged major parts illustrating the integration by binding the rotary shaft to the rotor, and illustrating the spacer. Figure (f) shows a top view of the spacer. Fig. 5 illustrates a groove for cooling that is a part of the first dispersing device in Fig. 3 and another example of the stator that has the groove. Figure (a) shows another example of the stator that can be used for the first dispersing device in Fig. 3. The figure shows a cross section taken along the same position as in Fig. 4(b). Figure (b) shows yet another example of the stator that can be used for the first dispersing device in Fig. 3 and also shows a cross section taken along the same position as in Fig. 4(b). Figure (c) shows a cross section taken along the line A6-A6 in Fig. 5(b). Fig. 6 illustrates another example of the container that is a part of the first dispersing device in Fig. 3. Figure (a) shows the first dispersing device where the container is replaced by a container having an agitating plate. Figure (b) shows the first dispersing device where the container is replaced by a container that is combined with a tank for storing the mixture after the process ends. Fig. 7 shows a schematic drawing of another embodiment of the dispersing system. The embodiment is suitable for a dispersing process that uses multiple paths. Fig. 8 shows a schematic drawing of yet another embodiment of the dispersing system. The embodiment uses air pressure for supplying the mixture. Fig. 9 shows a schematic drawing of yet another embodiment of the dispersing system, where the capability for a rough dispersion is enhanced.

Below, some embodiments of the present invention are discussed with reference to the drawings. First, a dispersing system 100 is discussed with reference to Fig. 1. The dispersing system 100 comprises a rough-dispersing device 110 that mixes together (also called a “rough-dispersion”) a liquid material L and a powdery material P to obtain a mixture 4 of a slurry. It also comprises a first dispersing device 1 that preliminarily disperses by means of a shearing force the mixture 4 that is supplied from the rough-dispersing device 110. It also comprises a second dispersing device 60 that makes solid particles in the mixture 4 finer to be on a nanometer scale, which mixture has been preliminarily dispersed by the first dispersing device 1 (also called “dispersion to be on a nanometer scale” or “finishing dispersion”). It also comprises a storage tank 120 that stores the mixture 4 that has been dispersed by means of the second dispersing device 60.

Solid particles on a nanometer scale are particles of which the mean diameter is less than 1 micrometer. The lower limit of the mean diameter is not determined, but usually 1 nm. The mean diameter can be determined by measuring the distribution of the particle sizes by means of a laser diffraction particle size analyzer or the like (for example, SALD-2100, available from Shimadzu Corporation, Japan) and by calculating a median size from the measured sizes.

The dispersing system 100 further comprises a piping 130 that conveys the mixture 4 from the rough-dispersing device 110 to the first dispersing device 1, a piping 140 that conveys the mixture 4 that has been preliminarily dispersed from the first dispersing device 1 to the second dispersing device 60, and a piping 150 that conveys the mixture that has been dispersed to be on a nanometer scale from the second dispersing device 60 to the storage tank 120. A pump 132 and a pump 142 are provided to the piping 130 and the piping 140, respectively. If the second dispersing device 60 is exposed to the atmosphere, a pump is also provided to the piping 150. Incidentally, the mixture 4 may be conveyed from the rough-dispersing device 110 to the first dispersing device 1 by means of gravity without the pump 132.

The rough-dispersing device 110 has a part 111 for supplying a liquid material that supplies the liquid material L and a part 112 for supplying a powdery material that supplies the powdery material P. The part 111 for supplying the liquid material and the part 112 for supplying the powdery material may be structured in line with any structure that is publicly known. The rough-dispersing device 110 has a rotary shaft 117 and agitating blades 113 so as to accelerate mixing the liquid material L and the powdery material P that have been supplied. It also has a driving unit 118, such as a motor, to rotate the agitating blades 113 about the rotary shaft 117. The agitating blades 113 are formed so that each clearance between the agitating blades 113 and the wall is about 0 to 20 mm. The agitating blades 113 are made of metal or metal and resin. By using the agitating blades 113 that are made of metal and resin, contamination caused by metal can be prevented. Here, the agitating blades 113 are formed so as to be able to scrape off any slurry at two points on a circle. However, three agitating blades may be used by combining multiple plates, or just one may be used. A method to accelerate mixing is not limited to rotating the agitating blades 113, but may be any other method that is publicly known.

In Fig. 1, the anchor-type agitating blades 113 are shown. However, the agitating blades are not limited to the anchor-type, but may be a turbine-type impeller 114, such as a disk turbine type impeller as in Fig. 2(a). The agitating blades 114 generate an oblique vortex in the mixture 4 (at first a raw material to be processed) in the rough-dispersing device 110. Disperse-type (dissolver-type impellers) agitating blades 115 as in Fig. 2(b) and propeller-type agitating blades 116 as in Fig. 2(c) may be used. Since these agitating

blades

113, 114, 115, 116 are used for agitating the mixture 4, the configuration of the rough-dispersing device 110 can be simple.

Carbon black, a carbon nanotube, a grapheme, an inorganic powder such as alumina or silica, a powder made of metal or metal oxide, etc., may be used as the powdery material P. A mixture of multiple kinds of powdery materials may be used. Water, a solvent such as ethanol, a resin, etc., may be used as the liquid material L. A mixture of multiple kinds of liquid materials may be used. An organic solvent other than ethanol may be used as a solvent. For example, a thermosetting resin may be used as the resin. For example, a combination of water and ethanol, ethanol and another solvent, or a solvent and a resin, may be used. There is no limitation to a combination of the powdery material P or the liquid material L. By dispersing the powdery material P that is on a nanometer scale in any of these liquid materials L, a product that has properties that have not been previously achieved can be obtained, such as a material having high elasticity or high heat resistance, a film having excellent insulation properties, an electric or electronic part having excellent electric properties, a chemical material having excellent chemical properties (for example, reactivity), a paint having excellent anticorrosion properties, or a lens having a high refractive index.

The first dispersing device 1 supplies the mixture 4 of a slurry to the gap between the rotor 2 and the stator 3 so as to disperse the mixture 4 by a shearing force. The details are discussed below.

The second dispersing device 60 may be any known dispersing device, such as a bead mill, a jet mill, or a high-pressure-type homogenizer. Since the mixture 4 is preliminarily dispersed by means of the first dispersing device 1, agglomerated particles are dissolved so that the mixture 4 includes only small particles of some tens of micrometers or less, as discussed below. Thus, an effective dispersion of particles to be on a nanometer scale can be achieved, and so no uneven dispersion occurs. If an uneven dispersion were to occur, a bead mill would not work because agglomerated particles that are larger than the beads would be contained. A jet mill or a high-pressure-type homogenizer would not work because agglomerated particles that are larger than the size of the nozzle would cause clogging. Thus an uneven dispersion or a problem in the device would occur.

The storage tank 120 has a rotary shaft 127, agitating blades 123, and a driving unit 128, such as a motor for rotating the agitating blades 123 about the rotary shaft 127, so that any uneven concentration of the mixture 4 that has been dispersed to be on a nanometer scale can be prevented. The method to agitate the mixture 4 is not limited to rotating the agitating blades 123, but may be any publicly known method. Since at any point in time the mixture 4 that has been dispersed by the rough-dispersing device 110 and by the first dispersing device 1 and the second dispersing device 60 that continuously process the mixture 4 does not necessarily have a constant concentration or a constant distribution of particles, the mixture 4 may be stored and agitated in the storage tank 120 so as to become even. Further, an uneven concentration due to sedimentation of solid particles can be prevented while the mixture 4 is stored in the storage tank 120. However, if the concentration and distribution of particles are ensured to be even, no agitating means may be provided to the storage tank 120. A vacuum pump (not shown) may be provided to the storage tank 120 and respective on-off valves (not shown) are provided to the

piping

140, 150. The mixture 4 that is on a nanometer scale can be defoamed by means of the vacuum pump and the on-off valves. If a contact seal, such as a lip seal, is installed in the first dispersing device 1 instead of the on-off valves, so as to prevent ambient air from entering, defoaming can be carried out while the mixture 4 is being dispersed.

Now, with reference to Figs. 3, 4, and 5, the shear-type dispersing device 1 is discussed. The first dispersing device 1 comprises a rotor 2 and a stator 3 that is disposed to face the rotor 2. It causes a slurry or liquid mixture 4 to flow between the rotor 2 and the stator 3 toward the outer circumference (toward the direction of the outer circumference) by centrifugal force to preliminarily disperse it.

The first dispersing device 1 comprises a container 11 for receiving the mixture 4 that has been dispersed and a cover assembly 12 for closing the upper opening 11a of the container 11. For example, the cover assembly 12 is fixed to the container 11 by placing bolts 11d through the bolt holes 11c in the upper rim 11b of the container 11 and the bolt holes 18c in the cover assembly 12 (a part 18 for holding the stator, which is discussed below), to close the upper opening 11a.

The stator 3 is fixed under the cover assembly 12 (to the lower surface of the cover assembly 12). For example, the stator 3 is fixed there by placing bolts 3a through the bolt holes 3b in the stator 3 and the bolt holes 18b in the cover assembly 12 (the part 18 for holding the stator). The rotor 2 is disposed to face the lower surface of the stator 3.

The first dispersing device 1 further comprises a rotary shaft 13 that rotates the rotor 2 and a bearing 14 that rotatably holds the rotary shaft 13. The bearing 14 is fixed to the cover assembly 12 and located above the stator 3.

The rotor 2 is disposed at one end of the rotary shaft 13. At the other end a rotary shaft 16a of a motor 16 that is disposed above the stator 3 is fixed via a joint 16b. The rotary shaft 13 is rotated by means of the motor 16 and transmits the force for rotation by the motor 16 to the rotor 2.

The first dispersing device 1 comprises a spacer 15 that is detachably disposed between the rotary shaft 13 and the rotor 2 (see Fig. 4c and Fig. 4e). The spacer 15 causes the gap between the rotor 2 and the stator 3 to be adjusted by being replaced by another one that has a different length (thickness) in the direction of the first dispersing device 1, i.e., the axial direction D1 of the rotary shaft 13 (see Fig. 3a). That is, spacers 15 that have various thicknesses are stocked so as to adjust the gap between the rotor 2 and the stator 3 by using one of them.

When the spacer 15 is disposed, the position of the rotor 2 in relation to the stator 3 in the axial direction D1 is fixed. That is, a spring or a screw may be used to adjust the gap between the rotor 2 and the stator 3. However, when the spacer 15 is used, since the axial position of the rotor 2 is fixed during the operation, no countermeasures against vibrations by the spring or looseness by the screw need be considered. Further, if a spring or a screw is used, it is difficult to accurately move the rotor 2 without the rotor 2 being inclined. On the contrary, when the spacer 15 is used the rotor can be accurately moved without it being inclined.

By the first dispersing device 1, the gap can accurately be adjusted by means of the above-mentioned structure. By the first dispersing device 1, even if the rotary shaft 13 is thermally expanded due to unforeseen heat, the rotor 2 moves in the direction to be separated from the stator 3. Thus any contact between the rotor 2 and the stator 3 can be prevented. Further, producing excessive heat due to an unforeseen small gap, even though they do not contact each other, can be prevented. Further, since the bearing 14 is located above the stator 3, the rotary shaft 13 is located over the rotor 2. Since no part of the rotary shaft 13 is disposed under the rotor 2 (the rotary shaft 13 is upwardly disposed from the rotor 2), a reduction in the yield due to adhesion of the processed mixture 4 on the rotary shaft 13, the bearing 14, etc., can be prevented. Namely, the yield can be improved.

The cover assembly 12 has a part 17 for holding the bearing 14 and the part 18 for holding the stator that is disposed under the part 17. The part 18 holds the stator 3. The part 17 for holding the bearing has a part 21 for controlling the axial position of the part 18 for holding the stator. The part 21 abuts the part 18 by means of a second spacer 20. For example, the part 17 is integrated with the part 18 by placing bolts 17a through the bolt holes 17e in the part 17 and the bolt holes 18e in the part 18 while the second spacer 20 is sandwiched between them (see Fig. 4d). Through-holes 20a are formed in the second spacer 20 so that the bolts 17a pass through them.

The second spacer 20 is detachably disposed between the part 17 for holding the bearing and the part 18 for holding the stator. It adjusts the position of the stator 3 in the axial direction D1 in relation to the part 17 by being replaced by another one that has a different length (thickness) in that direction D1. That is, the second spacers 20 that have various thicknesses are stocked so as to adjust the position of the stator 3 in the axial direction D1 by using one of them.

By replacing the spacer (also called “the first spacer”) 15 and the second spacer 20 with respective spacers, the gap between the rotor 2 and the stator 3 can be more precisely adjusted. That is, by replacing the spacer 15 with a thicker one, that gap becomes larger. By replacing the second spacer 20 with a thicker one, that gap becomes smaller. A combination of these replacements can achieve a more precise adjustment. For example, the spacers 15 and the second spacers 20 that have thicknesses from 0.01 mm to 0.50 mm in increments of 0.01 mm are stocked. They are replaced so that the gap between the rotor 2 and the stator 3 is adjusted to suit the viscosity and properties of the mixture 4.

The second spacer 20 causes the position of the stator 3 to be adjusted in relation to the part 17 for holding the bearing, i.e., the position of the lower surface of the stator 3, by the position of the part 18 for holding the stator in relation to the part 17 for holding the bearing being adjusted. Thus the position of the lower surface of the stator 3 can be kept constant regardless of the condition of the stator 3. For example, even when the stator 3 is replaced, the position of the lower surface of the stator 3 can be kept constant. Thus, for example, by keeping the position of the lower surface of the stator 3 at a predetermined position, the thickness of the spacer 15 can be the same as the gap between the rotor 2 and the stator 3, so that the structure is comprehensible to users. That is, to adjust the gap at a desired distance the spacer 15 that has the same thickness as the gap has to be chosen. This improves the convenience for the users who perform the dispersing process under the control of the gap.

A concave part 22 is formed on the upper surface of the rotor 2 so that the lower end 13a of the rotary shaft 13 is inserted into it (see Figs. 4c and 4e). A through-hole 22a that opens on the concave part 22 is formed in the rotor 2. The lower end 13a of the rotary shaft 13 is inserted into the concave part 22 of the rotor 2. The lower end 13a abuts the concave part 22 by means of the spacer 15. A fastening member 23 is fixed from the lower side of the rotor 2. The fastening member 23 is, for example, a bolt. In the lower end 13a of the rotary shaft 13 a female screw, as a fastening part 13b that is a counterpart of the fastening member 23, is formed.

The fastening member 23 fastens the rotary shaft 13 to the rotor 2 across the spacer 15 by fixing a part of it to the rotary shaft 13 through the hole 22a of the rotor 2. Pins 24 are inserted into the concave part 22 of the rotor 2 and the lower end 13a of the rotary shaft 13 to transmit the rotational power of the rotary shaft 13 to the rotor 2. Holes for receiving the pins 24 are formed in the concave part 22 of the rotor 2 and the lower end 13a of the rotary shaft 13.

The pins 24 are disposed at a uniform interval along the circumferential direction to transmit the rotational power of the rotary shaft 13 to the rotor 2. A first through-hole 15a through which the fastening member 23 passes and second through-holes 15b through which the pins 24 pass are formed in the spacer 15. In this embodiment four second through-holes 15b and four pins 24 are used. However, the number is not limited to four.

Since the rotary shaft 13 and the rotor 2 are fastened across the spacer 15 by the fastening member 23, the axial position of the rotor 2 in relation to the stator 3 is definitely fixed. Thus the gap between the rotor 2 and the stator 3 can be made appropriate. That is, the spacer 15 with the above-mentioned advantages is properly used.

Since the pins 24 are used for transmitting the rotational power from the rotary shaft 13 to the rotor 2, the distribution of the power in the circumferential direction is improved in comparison with a structure in which a key and a keyseat are used. That is, the rotary shaft 13 and the rotor 2 rotate in a balanced way. Thus the dispersing power between the rotor 2 and the stator 3 is prevented from differing at different locations. That is, a uniform and appropriate dispersing process can be carried out. Since the difference in the dispersing power at different locations is prevented, the dispersing process can be stable when the gap is narrowed. Further, since the speed of the rotation can be increased, an appropriate dispersing process can be carried out.

The stator 3 is bigger than the rotor 2 on the plane where it faces the rotor 2. That is, the stator 3 on the plane perpendicular to the axial direction D1 is shaped to be larger than the rotor 2. In the stator 3 a groove 26 for cooling is formed on the surface (the upper surface) opposite the surface (the lower surface) that faces the rotor 2 so that a coolant flows through it. The groove 26 for cooling is located beyond the outer edge of the rotor 2.

Since the groove 26 for cooling is formed beyond the outer edge of the rotor 2, the outer edge of the rotor 2 can be cooled. That is, the entire areas for dispersion of the rotor 2 and the stator 3 can be cooled by the groove 26 for cooling. Thus generating heat in the material (the mixture 4 being dispersed) can definitely be prevented. Thus the material that is to be dispersed is prevented from deteriorating. Further, even if the material is volatile and flammable, the dispersing process can be safely carried out. Conventionally, the rotor 2 and the stator 3 are shaped to have the same sizes on the plane they face. In such a case the outer edge cannot be cooled. Since the amount of heat generated is high at the outer edge, the groove 26 for cooling provides an excellent cooling effect. Thus the appropriate dispersing process can be carried out at an appropriate temperature range.

A wall 27 is formed along the radial direction on the groove 26 for cooling (see Fig. 4b). A port 28 for supplying the coolant and a port 29 for discharging the coolant are disposed across the wall 27 on the groove 26. The coolant that is supplied from the port 28 to the groove 26 flows toward the direction D3, in which no wall 27 is formed near the port 28, in the circumferential direction D2. That coolant is discharged from the port 29. For example, the coolant can be water.

Since the groove 26 for cooling is configured to cause the coolant to flow from the port 28 for supplying the coolant to the port 29 for discharging the coolant in a single direction, namely, it ends so as to cause the coolant to flow in a single direction, the coolant is discharged in order of precedence. In other words, if it were not configured to cause the coolant to flow in a single direction, a part of the coolant would stay, so that the coolant might not be replaced by new coolant at a part of the groove for cooling, deteriorating the cooling ability. By contrast, since the groove 26 for cooling is configured to replace the coolant in order of precedence, the cooling ability is constantly high. Thus the appropriate dispersing process at the appropriate temperature can be carried out.

The groove for cooling and the stator, on which the groove is formed, which constitute the first dispersing device 1, are not limited to the above-mentioned structure. For example, as shown in Fig. 5, the

stators

76, 77 with the

grooves

71, 72 for cooling may be used. Fig. 5a illustrates an example by which the cooling ability is enhanced by widening the groove as much possible, except where the screws are located. Fig. 5b illustrates an example by which the cooling ability is enhanced by increasing the area to contact the coolant by forming fine grooves on the bottom of the groove. Fig. 5c shows a cross section taken along the line A6-A6 in Fig. 5b to illustrate the section of the fine grooves, or concave parts, 72a. Since the

stators

76, 77 have the same structure and function as the stator 3 except for the groove for cooling, a duplicate explanation is omitted.

As in Fig. 5, like the groove 26 for cooling, the

grooves

71, 72 for cooling are formed in the upper surfaces of the

stators

76, 77, respectively, which stators are larger than the rotor 2, so as to reach outside the rotor 2. Like the wall 27, the

walls

73, 74 are provided to the

grooves

71, 72 for cooling. A structure that is similar to that of the groove 26 for cooling has similar functions.

Next, a structure that differs from that of the groove 26 for cooling is discussed. The groove 71 for cooling is extended to the outer edge of the stator 76. In the portions in which the bolt holes 3b are formed, protrusions 71a are formed. Since the groove 71 extends toward the outer edge, the cooling effect is enhanced. On the bottom of the groove 72 for cooling concave parts 72a are formed in the circumferential direction. Thereby, the amount of heat exchange between the coolant and the stator 76 increases so as to increase the cooling effect. The

grooves

71, 72 have a higher cooling effect than the groove 26 does. As discussed above, when the stator that has either of the

grooves

71, 72 for cooling, instead of the groove 26 for cooling, is used, a high cooling function is obtained so that an appropriate dispersing process within an appropriate temperature range is carried out.

In the stator 3 a hole 31 for inserting the rotary shaft is formed through which the rotary shaft 13 passes. The mixture 4 is supplied from outside the positions of the hole 31 of the stator 3 to the gap between the stator 3 and the rotor 2.

　 Specifically, a through-hole 32 for supplying the mixture 4 is formed outside the hole 31 for inserting the rotary shaft in the stator 3. In other words, the through-hole 32 is located a certain distance from the hole 31. A port 33 for supplying the mixture, and a passage 34 that communicates with the through-hole 32 for supplying the mixture to the port 33 and is provided in the stator 3, are provided in the part 18 for holding the stator. The mixture 4 that is supplied from the port 33 is introduced to the gap between the stator 3 and the rotor 2 through the passage 34 in the part 18 and the through-hole 32 in the stator 3. A flange for a connection is provided to an end of the port 33 for supplying the mixture so as to connect with a piping 130.

By this configuration, when the rotor 2 is rotated while the mixture 4 is supplied, the mixture 4 that has been supplied to the through-hole 32 is caused to flow outwardly by means of centrifugal force. Thus no mixture 4 reaches near the center of the rotation. Thus no sealing member such as a mechanical seal is required in the hole 31 for inserting the rotary shaft (also called “a first hole for inserting the rotary shaft”) or a second hole 36 for inserting the rotary shaft, which second hole 36 is discussed below. Namely, the through-hole 32 is located at such a distance from the hole 31 for inserting the rotary shaft that no mixture 4 flows to the hole 31. Thus the structure of the dispersing device can be simplified. Further, no replacement of the sealing member due to deterioration is needed.

The port 33 for supplying the mixture and the passage 34 are inclined in the direction D4, toward the radial center, as they become lower. However, they may be inclined, for example, in the tangential directions D5, D6 as they become lower. The port 33 for supplying the mixture and the passage 34 are formed so that the bottom end of the passage 34 is located at a position to be connected to the through-hole 32. Thus the through-hole 32 can be located near the hole 31.

The second hole 36 for inserting the rotary shaft, through which the rotary shaft 13 is inserted, is formed in the part 18 for holding the stator. A labyrinth seal 37, which is a noncontact seal, is provided to the second hole 36. Here the labyrinth seal has a configuration that has concavo-convex gaps in series between the rotary shaft and the fixed part by forming one or multiple concave parts and/or convex parts on one or both of the sides of the rotary shaft (the rotary shaft 13) and the fixed side (the part 18 for holding the stator). Such a configuration functions as a seal. The sizes of the concave parts and the convex parts are, for example, 0.01 - 3.00 mm.

Air is supplied from outside the part 18 for holding the stator to a space 38 that is located within the part 18 and connected to the upper part of the second hole 36 for inserting the rotary shaft. By supplying air from outside the part 18 a seal 39 by air purging is provided. For example, the seal 39 by air purging has a space 38 that is formed by the part 17 for holding the bearing and the part 18 for holding the stator, a passage 39b for purging that is formed in the part 17 and that connects the space 38 to the outside, and a part 39a for supplying air that is provided at the outer side of the passage 39b to supply air for purging. The seal 39 by air purging supplies air that is supplied from the part 39a to the gap between the second hole 36 and the rotary shaft 31 through the passage 39b and the space 38 as shown by the arrow F1. This air provides the sealing function.

On the outside of the second hole 36 in the part 18 for holding the stator a concave part 18f is formed to receive a bolt 3a for fixing the stator 3 to the part 18. Since the concave part 18f is formed, an inner circumference 18g that forms the second hole 36 for inserting the rotary shaft is shaped like a projection. The rotary shaft 13 has a projection 13g that projects over the inner circumference 18g of the part 18. As shown by the arrow F1, the air that has been supplied from the part 39a passes through the gap between the inner circumference 18g and the projection 13g and is supplied to the gap between the second hole 36 for inserting the rotary shaft and the rotary shaft 31.

The labyrinth seal 37 enhances the sealing effect on the second hole 36 for inserting the rotary shaft. The seal 39 by air purging enhances the sealing effect on the hole 31 for inserting the rotary shaft and the second hole 36 for inserting the rotary shaft by means of purging. In the first dispersing device 1 as discussed above, since the mixture 4 is introduced to such a position that centrifugal force is effectively utilized, neither a labyrinth seal nor a purging mechanism must be provided. However, one of these may be provided to enhance the sealing effect. Both may be provided to further enhance the sealing effect.

The container 11 has a conical wall 42 that has a smaller cross section from the top to the bottom, a cylindrical wall 43 that is located on the conical wall 42, and a port 44 for discharging at the lower end of the conical wall 42. The port 44 for discharging is provided at the lower end of the container 11 to discharge the mixture 4 that has been dispersed. At the end of the port 44 a flange for a connection is provided so that a piping 140 is connected to it. Since the mixture 4 after being dispersed is discharged through the conical wall 42, the amount of the mixture 4 that adheres to the inner wall and that is not discharged drastically decreases. Thus the yield is improved and an appropriate process is carried out. A vacuum pump may be provided to the container 11 so that air is prevented from being mixed in the mixture 4.

　 A cooling mechanism 41 that has a cooling function is provided to the container 11. For example, the cooling mechanism 41 includes the wall 42 and the wall 43 that together form the outer surface of the container 11. It also has a member 45 for forming the space that covers the outer surface (the wall 42 and the wall 43), which member is located outside the walls. It also has a port 46 for supplying a cooling medium and a port 47 for discharging a cooling medium. For example, the member 45 for forming the space may be a member that is generally called a jacket and forms a space 48 between it and the

walls

42 and 43 so that a cooling medium, such as cooling water, is filled in it.

For example, the port 46 for supplying a cooling medium is provided on the lower side of the member 45 for forming the space so as to supply the cooling water to the space 48. For example, the port 47 for discharging the cooling medium is provided on the upper side of the member 45 for forming the space so as to discharge the cooling water from the space 48.

By the above configuration the cooling mechanism 41 has a function to cool the inside of the container 11 through the

walls

42, 43. The cooling mechanism 41 also cools the mixture 4 that has been dispersed. If the mixture 4 includes a volatile material, the vaporized material is cooled to return to a liquid form. The structure of the cooling mechanism 41 is not limited to the above-mentioned one, but may be any known structure.

The container that constitutes the first dispersing device 1 is not limited to the container 11, but may be the

containers

81, 86 as in Fig. 6. First, the container 81 as in Fig. 6a is discussed. The container 81 has the same structure and functions as those of the container 11 except for having an agitator 82. So a duplicate explanation is omitted.

The container 81 as in Fig. 6a has the

walls

42, 43 and the port 44 for discharging. The container 81 is equipped with the cooling mechanism 41. The container 81 is also equipped with the agitator 82. The agitator 82 scrapes the slurry mixture 4 that adheres to the inner surfaces of the

walls

42, 43. The scraped mixture 4 is discharged, together with the mixture 4 that has not adhered, from the port 44 for discharging. The agitator 82 has an agitating plate 82a that is shaped so as to follow the shape of the

walls

42, 43 and a motor 82b that rotates the plate 82a. The agitator 82 also has a rotary shaft 82c and a bearing 82d. The agitating plate 82a is shaped so that the clearance between it and the

walls

42, 43 is about 0 - 20 mm. The agitating plate 82a is made of metal or metal and resin. Here the agitating plate 82a has two agitating parts 82e so as to scrape at two positions on the circumference. However, it may have three or more agitating parts by combining plates, or just one agitating part. In the example shown in Fig. 6a, from the need to dispose the rotary shaft 82c the port 44 for discharging is connected to a connecting pipe 83 so as to be connected to the piping 140 through it. Since the mixture 4 after being dispersed is discharged through the conical wall 42, the amount of the mixture 4 that adheres to the inner wall and that is not discharged drastically decreases. Further, the agitating plate 82a facilitates the discharge of the mixture 4. Thus the yield is improved.

Next, as another example of the container that constitutes the first dispersing device 1, the container 86 as in Fig. 6b is discussed. The container 86 doubles as a tank for storing the mixture 4 after being dispersed. Namely, the container 86 has a cylindrical wall 86a and a spherical bottom 86b that is located under the cylindrical wall 86a. A port 86c for discharging is provided at the lower end of the bottom 86b with an on-off valve 86d.

The container 86 as in Fig. 6b is compatible with the mixture 4 that is completely dispersed in a single dispersion, as discussed below. For example, it is compatible with a process for dispersing a small amount of the mixture 4, that needs to be appropriately dispersed, and that is expensive. After the process for dispersing, the bolts 11d are removed to dismount the container 86 from the cover assembly 12, or the rotor 2 and the stator 3 that are attached to the cover assembly 12. The container 86 can be directly used as a container for transporting and be transported to a desired location. Thus the mixture 4 that would adhere to the outer surface of the first dispersing device 1 in another structure can be recovered, so that the yield is improved. The shape of the container 86, which doubles as the tank for storing the mixture after the process, is not limited to it, but may be conical. Alternatively, it may be a large tank for accepting a large amount of the mixture being dispersed, or for being, for example, divided into two parts. The container that doubles as the tank for storing the mixture after the process may be equipped with the cooling mechanism 41.

For example, a stainless steel, such as SUS304, SUS316, SUS 316L, or SUS 430, as stipulated in the Japanese Industrial Standards (JIS), or a carbon steel, such as S45C or S55C, as stipulated in JIS, may be used for the raw material of the rotor 2 and the stator 3, which constitute the first dispersing device 1. A ceramic, such as alumina, silicon nitride, zirconia, sialon, silicon carbide, or a tool steel, such as SKD or SKF, as stipulated in JIS, may be used. A metal such as a stainless steel on which a ceramic is thermal sprayed (for example, alumina thermal spraying or zirconia thermal spraying) may be used. By using the rotor and the stator that are made of a metal on which a ceramic is thermal sprayed, the life can be prolonged and any contamination by metal can be prevented.

By the process for preliminarily dispersing in which the first dispersing device 1 is used the mixture 4 is supplied between the rotor 2 and the stator 3 of the first dispersing device 1 to cause the mixture 4 to flow toward the outer circumference by centrifugal force so that the mixture 4 is dispersed. By the first dispersing device 1 and the process for preliminarily dispersing, the yield is high, the dispersing power is high, and the dispersing process is carried out within an appropriate temperature range. That is, an appropriate preliminarily dispersing process is carried out. By the first dispersing device 1 and the process for preliminarily dispersing, since the container 11 and the cover assembly 12 can be separated for cleaning after the dispersing process, the cleaning is easy.

As discussed above, by the first dispersing device 1 the gap between the rotor 2 and the stator 3 that disperses by means of a shearing force can be adjusted and can definitely be fixed. Further, the rotor 2 is rotated in a balanced manner so as to evenly disperse the mixture. Thus, the preliminary dispersion of the mixture 4 that contains large particles of some hundreds to a thousand micrometers, which have been roughly dispersed, can be definitely carried out.

In the first dispersing device 1 the gap between the rotor 2 and the stator 3 is preferably 10 micrometers or more, and 1,000 micrometers or less. If it were less than 10 micrometers, the rotor 2 and the stator 3 would come close to each other, to thereby increase the risk that they would contact each other and be damaged because of thermal expansion due to heat generation during dispersion. If it were more than 1,000 micrometers, dispersing solid particles would become difficult. When the gap between the rotor 2 and the stator 3 is 10 micrometers or more, and 1,000 micrometers or less, dispersing the solid particles to be fine on some level, for example, to cause the mean diameter to be less than some tens of micrometers, preferably to be less than 10 micrometers, can be efficiently carried out.

Incidentally, a shear-type third dispersing device (not shown) may be provided between the rough-dispersing device 110 and the first dispersing device 1. In such a case, for example, the third dispersing device may have a gap of 1,000 micrometers between the rotor and the stator, so that the solid particles in the mixture 4 are dispersed to be less than 100 micrometers. The first dispersing device 1 may have a gap of 100 micrometers between the rotor 2 and the stator 3 so that the solid particles in the mixture 4 are dispersed to be less than 10 micrometers so as to supply the mixture 4 to the second dispersing device 60. Thus, even though the mixture that is supplied from the rough-dispersing device 110 contains large particles, the preliminary dispersion of it can be definitely carried out within a short time.

Since the first dispersing device 1 disperses the mixture 4 by shearing force, even dispersion can be achieved. Namely, since the mixture 4 is caused to flow between the rotor 2 and the stator 3, the shearing force is applied to all of the mixture 4. Thus no local variation (so called “short path”) in the shearing force that is applied to the mixture 4 exists, so that efficiency in the dispersion becomes high.

The shear-type dispersing device 1 as in Figs. 3 to 6, which is discussed as the first dispersing device, may be used to disperse particles to be on a nanometer scale as the second dispersing device 60, depending on the mixture 4. Namely, the gap between the rotor 2 and the stator 3 in the shear-type dispersing device 1 is set close so as to be used for dispersing particles to be on a nanometer scale. A dispersing system that comprises the shear-type dispersing device 1 as the first dispersing device and the shear-type dispersing device 1 as the second dispersing device that has a gap between the rotor 2 and the stator 3 that is smaller than that of the former one can efficiently carry out a preliminary dispersion and can disperse particles in the mixture to be on a nanometer scale.

Next, some variations of the dispersing system 100 are discussed with reference to Figs. 7 and 8. Fig. 7 is a schematic drawing of a dispersing system 102 that is suitable for a dispersing process that uses multiple paths. The dispersing system 102 has the same configuration and the same functions as the system 100, which is above discussed, except that it has multiple paths.

　 As in Fig. 7, the dispersing system 102 comprises the rough-dispersing device 110, an intermediate tank 112, the first dispersing device 1, the second dispersing device 60, and the storage tank 120. A piping 134 connects the downstream part of the pump 142 in the piping 140 to the intermediate tank 112 and to the rough-dispersing device 110. A piping 136 connects the intermediate tank 112 to the upstream part of the pump 132 in the piping 130. The mixture 4 that has been preliminarily dispersed by means of the first dispersing device 1 is stored in the intermediate tank 112. Then it is returned to the first dispersing device 1 so as to repeat the preliminary dispersion. Further, the mixture 4 that has been preliminarily dispersed by means of the first dispersing device 1 may be returned to the rough-dispersing device 110. Namely, by the dispersing system 102, the preliminary dispersion is repeated, to facilitate a preliminary dispersion so that large particles are dispersed to be solid particles with the mean diameter of 10 micrometers or smaller, for example.

As in Fig. 8, a dispersing system 104 comprises the rough-dispersing device 110, the first dispersing device 1, the second dispersing device 60, and the storage tank 120, like the dispersing system 100 does. However, no pump is provided to the piping 130. A compressor 160 is connected to the rough-dispersing device 110 through a flow control valve 162 and a filter 164. That is, the flow control valve 162 and the filter 164 are provided to the piping 166 that connects the rough-dispersing device 110 with the compressor 160. The flow control valve 162 regulates the flow of compressed air that is introduced from the compressor 160 to the rough-dispersing device 110. The filter 164 removes unwanted materials from that compressed air.

By the dispersing system 104, the powdery material and the liquid material are roughly dispersed without being pressurized. Then, the mixture 4 in the rough-dispersing device 110 is pressurized by means of the compressor 160 and the flow control valve 162. Thus the mixture 4 is introduced by means of the pressure from the rough-dispersing device 110 to the first dispersing device 1 through the piping 130.

Next, a dispersing system 106 as in Fig. 9 is discussed as another example of the dispersing system. The dispersing system 106 is characterized in that it comprises a rough-dispersing device 170 that is excellent in mixing a powdery material with a liquid material when the powdery material is hydrophobic to float on the surface of the liquid or to clump (a large body that is made by powders that absorb liquids). It has the same configuration and the same functions as the dispersing system 100 as in Fig. 1 except that it comprises the rough-dispersing device 170 instead of the rough-dispersing device 110. A duplicate explanation is omitted.

The rough-dispersing device 170 has the part 111 for supplying the liquid material and the part 112 for supplying the powdery material. It also has agitating blades 173, a rotary shaft 177 that is connected to the agitating blades 173, and a driving unit 178, such as a motor, to rotate the rotary shaft 177. The rotary shaft 177 is eccentric from the center of the rough-dispersing device 170 (it is located so as to deviate from the center) so that an oblique vortex is generated by the rotation of the agitating blades 173. The rough-dispersing device 170 has a cylindrical side and a curved bottom, for example. However, it is not limited to that shape.

The part 112 for supplying the powdery material supplies the powdery material P into the oblique vortex that is generated by means of the agitating blades 173. It may be a metering-type vibrating feeder, for example. However, it is not limited to that type, but may be another type of vibrating feeder or a screw-type feeder. The powdery material that is supplied into the oblique vortex is prevented from clumping. Thus it is dispersed by means of the rough-dispersing device 170 without clumping. Further, since the agitating blades 173 are rotated at a position that deviates from the center, a wide space for supplying the raw materials from the part 111 for supplying the liquid material and the part 112 for supplying the powdery material can be secured. Further, the accuracy of the ratios of the materials used for the mixture 4 can be increased.

As discussed above, by the dispersing

system

100, 102, 104, and 106, the mixture 4 is preliminarily dispersed by the first dispersing device 1. The mixture 4 that has been preliminarily dispersed is dispersed by the second dispersing device 60 to be on a nanometer scale. Thus solid particles are efficiently made finer to be on a nanometer scale.

Below, the main reference numerals and symbols that are used in the detailed description and drawings are listed.
1 the first dispersing device
2 the rotor
3 the stator
4 the mixture
11 the container
11a the upper opening
12 the cover assembly
13 the rotary shaft
13a the lower end
14 the bearing
15 the spacer
15a the first through-hole
15b the second through-hole
17 the part for holding the bearing
18 the part for holding the stator
20 the second spacer
21 the part for controlling the axial position
22 the concave part
23 the fastening member
24 the pin
26 the groove for cooling
27 the wall
28 the port for supplying the coolant
29 the port for discharging the coolant
31 the hole for inserting the rotary shaft
32 the through-hole for supplying the mixture
33 the port for supplying the mixture
34 the passage
36 the second hole for inserting the rotary shaft
37 the seal
38 the space
41 the cooling mechanism
44 the port for discharging
60 the second dispersing device
82 the agitator
82a the agitating plate
100, 102, 104, 106 the dispersing system
110, 170 the rough-dispersing device
111 the part for supplying the liquid material
112 the part for supplying the powdery material
113, 114, 115, 173 the agitating blades
117, 177 the rotary shaft
118, 178 the driving unit
120 the storage tank
130, 140, 150 the piping
132, 142 the pump
L the liquid material
P the powdery material

Claims

A dispersing system that disperses a mixture of a slurry comprising:
a first shear-type dispersing device that causes the mixture to flow between a rotor and a stator that is disposed to face the rotor toward an outer circumference by centrifugal force to disperse the mixture; and
a second dispersing device that makes solid particles finer to be on a nanometer scale in the mixture that has been dispersed by means of the first dispersing device.
The dispersing system of claim 1, wherein the first dispersing device has:
a container for receiving the mixture that has passed between the rotor and stator,
a cover assembly for closing an upper opening of the container,
the stator that is fixed to a bottom of the cover assembly,
the rotor that is disposed to face a lower face of the stator, and
a rotary shaft that rotates the rotor,
wherein a gap between the rotor and the stator is 10 micrometers or larger, and 1,000 micrometers or smaller.
The dispersing system of claim 2, wherein the second dispersing device is any of a bead mill, a jet mill, and a high-pressure-type homogenizer.
The dispersing system of any of claims 1 to 3, wherein a mean diameter of the solid particles in the mixture before being dispersed by the first dispersing device is 1 micrometer or greater, and 1,000 micrometers or smaller, and a mean diameter of the solid particles in the mixture after being dispersed by the second dispersing device is less than 1 micrometer.
The dispersing system of any of claims 1 to 3, wherein the mixture to be dispersed by the dispersing system is a mixture of one or more powdery materials that are selected from a group of carbon black, a carbon nanotube, a grapheme, an inorganic powder, and a powder made of a metal or a metal oxide and one or more liquid materials that are selected from a group of water, a solvent, and a resin.
The dispersing system of claim 4, further comprising:
a rough-dispersing device that disperses the mixture that is to be supplied to the first dispersing device, wherein the rough-dispersing device mixes together a powdery material and a liquid material, both of which are raw materials of the mixture.
The dispersing system of claim 6, wherein the rough-dispersing device has any of a turbine-type impeller, a dispersing-type impeller, a propeller-type impeller, and an anchor-type impeller.
The dispersing system of claim 6, further comprising:
a third dispersing device that causes the mixture that has been dispersed by means of the rough-dispersing device to flow between a rotor and a stator that is disposed to face the rotor toward the outer circumference by centrifugal force to disperse it to supply the dispersed mixture to the first dispersing device.
The dispersing system of claim 2 or 3, wherein the first dispersing device has:
a bearing that is disposed in the cover assembly and disposed above the stator and that rotatably holds the rotary shaft,
a spacer that is detachably disposed between the rotary shaft and the rotor and that adjusts a gap between the rotor and the stator,
wherein, when the spacer is disposed, a position of the rotor in relation to the stator in an axial direction is fixed.
The dispersing system of claim 9, wherein the cover assembly has a part for holding the bearing that holds the bearing and a part for holding the stator that is provided under the part for holding the bearing and that holds the stator,
wherein the part for holding the bearing has a part for controlling an axial position that controls an axial position of the part for holding the stator by contacting the part for holding the bearing with the part for holding the stator through a second spacer,
wherein the second spacer is detachably provided between the part for holding the bearing and the part for holding the stator so as to adjust an axial position of the stator in relation to the part for holding the bearing by being exchanged with one that has a different length,
wherein a concave part is formed on an upper surface of the rotor so that a lower end of the rotary shaft is inserted into the concave part,
wherein a through-hole opens on the concave part,
wherein the lower end of the rotary shaft is inserted into the concave part of the rotor wherein a fastening member is fixed from a lower surface of the rotor while the lower end abuts the concave part through the spacer,
wherein the fastening member fastens the rotary shaft to the rotor across the spacer by fixing a part of the fastening member to the rotary shaft through the through-hole of the rotor,
wherein a plurality of pins are inserted into the concave part of the rotor and the lower end of the rotary shaft to transmit a rotational power of the rotary shaft to the rotor,
wherein the pins are disposed at uniform intervals along a circumferential direction, and
wherein a first through-hole, through which the fastening member is inserted, and second through-holes, through which the pins are inserted, are formed in the spacer.
The dispersing system of claim 10, wherein the stator is bigger than the rotor on a plane where the stator faces the rotor,
wherein in the stator a groove for cooling is formed on a surface opposite the surface that faces the rotor, so that a coolant flows through the groove for cooling,
wherein the groove for cooling is located beyond an outer edge of the rotor,
wherein a wall is formed along a radial direction on the groove for cooling
wherein a port for supplying coolant and a port for discharging the coolant are disposed across the wall,
wherein the coolant that is supplied from the port for supplying the coolant to the groove flows toward a direction in which no wall is formed near the port for supplying the coolant, in the circumferential direction, and the coolant is discharged from the port for discharging the coolant,
wherein in the stator a hole for inserting the rotary shaft is formed, through which hole the rotary shaft passes, and the mixture is supplied from outside the positions of the hole of the stator to the gap between the stator and the rotor.
The dispersing system of claim 11, wherein a through-hole for supplying the mixture is formed outside the hole for inserting the rotary shaft in the stator,
wherein a port for supplying the mixture, and a passage that communicates with the through-hole for supplying the mixture to the port for supplying the mixture and is provided in the stator, are provided in the part for holding the stator,
wherein the mixture that is supplied from the port for supplying the mixture is introduced to the gap between the stator and the rotor through the passage in the part for holding the stator and the through-hole in the stator,
wherein a second hole for inserting the rotary shaft, through which the rotary shaft is inserted, is formed in the part for holding the stator,
wherein a labyrinth seal is provided to the second hole for inserting the rotary shaft,
wherein air is supplied from outside the part for holding the stator to a space that is located within the part for holding the stator and connected to an upper part of the second hole for inserting the rotary shaft, and
wherein a cooling mechanism is provided to the container.
The dispersing system of claim 12, wherein the container has a conical wall wherein a cross section decreases from a top to a bottom,
wherein a port for discharging is provided at a lower end of the container to discharge the mixture that has been dispersed, and
wherein an agitating plate is provided to the container so as to scrape off the mixture of any slurry that adheres to the wall.
The dispersing system of claim 13, wherein the rotor and the stator are made of a stainless steel on which a ceramic is thermal sprayed.
A process for dispersing that disperses a mixture of a slurry, the process comprising:
a step of supplying a mixture to a gap between a rotor and a stator that is disposed to face the rotor of a first dispersing device;
a step of causing the mixture to flow outwardly between the rotor and the stator by means of centrifugal force to disperse the mixture by shearing force by means of the rotor and the stator;
a step of supplying the mixture that has been dispersed by the first dispersing device to a second dispersing device; and
a step of making solid particles, in the mixture that has been supplied to the second dispersing device, finer, to be on a nanometer scale, by means of the second dispersing device.