JPH0515937Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention is applicable to mixtures in which a dispersoid is mixed with a viscous (slurry) dispersion medium, such as ink, paint, magnetic paint for magnetic recording media, etc. This invention relates to a dispersing machine for uniformly dispersing in a medium. [Prior Art] A conventional dispersion machine used for the above-mentioned mixture is shown in FIGS. 5 and 6. As shown in FIG. 5, a shaft 6 rotatably driven by a motor 5 is arranged in a cylindrical container 4, and a stirring plate 7,
7... are fixed at regular intervals via spacers 9, 9.... As shown in FIG. 6, the stirring plates 7, 7... each have a groove 13 extending spirally from the center.
, and are fixed to the shaft 6 at a constant interval while being sandwiched between spacers 9, 9, . . . The container 4 has an inlet 14 at the lower part and an outlet 15 at the upper part, and a screen 20 is provided in front of the outlet 15. The mixture of dispersion medium and dispersoid is sent from the tank 2 side through the duct 12 to the pump 3, where it is given a pressure of about 0.3 to 5.0 Kg/cm ² , and is then sent through the duct 11 from the inlet 14 to the container. 4 is pressurized and introduced. In the container 4, about 40 to 90% of the volume of the container is stored with fine granular media having a particle size of 0.5 to 3 mm. This media includes the stirring plates 7, 7...
passes through the kerf 13, but does not pass through the screen 20. In this disperser, the mixture pressurized and introduced into the container 4 from the introduction port 14 is stirred and mixed together with the media by the rotation of the stirring plate 7, so that the dispersoid is gradually and uniformly dispersed in the dispersion medium. Spread.
Furthermore, in addition to the action of the rotation of the stirring plate 7, this mixture is pushed by the mixture pumped from the inlet 14 and gradually rises inside the container. At this time, by passing the media together with the grooves 13 of the stirring plate 7, the mixture is agitated and the dispersoids are more uniformly dispersed in the dispersion medium. After the mixture is separated from the media by the screen 20, it is taken out of the container 1 from the outlet 15. In order to perform efficient and high-capacity dispersion in this dispersing machine, it is necessary to satisfy various conditions, but in particular, the media must be almost uniformly dispersed in the mixture in the container 4. This is very important. [Problems to be solved by the invention] Conventionally, various devices have been devised to prevent the media from being unevenly distributed in a specific location in the container 4. Measures have been taken to appropriately select the introduction pressure, etc., or to harmonize the number of rotations of the stirring plate 7 with the introduction pressure of the mixture. However, no matter how well the conditions are adjusted for mixing and dispersion, changes in the rheological properties of the mixture tend to cause the media to settle downward in the mixture, and the media tends to be biased toward the bottom of the container.
Therefore, if the dispersing machine continues to operate, a difference in the distribution of the media inevitably arises between the upper and lower sides of the container, and this becomes larger. For this reason, the dispersion ability of the disperser gradually decreases. Furthermore, dispersion of the mixture using only the stirring plate 7 has a limited ability, and the reality is that it takes a long time to obtain a high degree of dispersion. In view of the above-mentioned conventional problems, the present invention has been developed to provide a dispersion system that can maintain a state in which the media is uniformly dispersed in the container during operation, and that can obtain a high degree of dispersion in a short period of time. The purpose is to provide a machine. [Means for Solving the Problems] That is, in order to solve the above problems, the means adopted in the present invention is to provide an inlet 14 for introducing the mixture into the container 4 under pressure, and an inlet 14 for discharging the mixture out of the container 4. A viscous mixture dispersing machine is provided with a discharge port 15 and a rotationally driven stirring plate 7 for stirring the mixture and granular media in the container 4. only pass through,
A screen 8 having a large number of holes that prevents the passage of media is used to divide the chamber into a plurality of vertically divided chambers 16, 16, including the stirring plate 7, and the cross-sectional area of the holes 8a, 8b. The purpose is to vary the mixture along the direction of movement through the . [Function] In the dispersing machine, the inside of the container 4 is divided into a plurality of sections, and the divided rooms 16, 16... are partitioned by screens 8, 8... that do not allow the media to pass through, so that the media can be separated from each other. room 16,
Move only in 16... and move to other rooms 16, 16
It does not move to... And these rooms 16,
16 are divided into upper and lower sections, so that the screens 8, 8 prevent the media, which tends to settle in the mixture, from descending. Therefore, during long-term operation of the disperser, the overall uniform dispersion state of the media is maintained. In addition, the mixture flows from each chamber 16, 16 into the through holes 8a, 8b of the screens 8, 8, . Accompany. In addition, since the cross-sectional area of the through holes 8a and 8b changes along the moving direction of the mixture passing through them, the pressure and flow rate are also fluctuated while the mixture is passing therethrough. Since this has the same effect as stirring the mixture, the dispersoid is diffused into the dispersion medium also when passing through the screen 8, and is dispersed more uniformly. [Example] Next, an example of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a cylindrical container 4 is installed on a frame 1, and a shaft 6 rotated by a motor 5 is inserted into the container 4. As shown in FIG. Stirring plates 7, 7, . . . are fixed to this shaft 6 at regular intervals via spacers 9, 9, .
As shown in FIG. 2, the stirring plates 7, 7, . . . have a groove 13 extending spirally from the center. The container 4 is provided with an inlet 14 at the lower part and an outlet 15 at the upper part, and the mixture of the dispersion medium and the dispersoid is sent from the tank 2 side to the pump 3 via the duct 12, where the concentration of 0.3 to 5.0 A pressure of about Kg/cm ² is applied, and the material is pressurized and introduced into the container 4 through the introduction port 14 through the duct 11. Furthermore, inside the container 4, screens 8, 8
It is partitioned vertically into a plurality of rooms 16, 16... by.... This point will be explained in more detail with reference to the drawings. Various configurations of the screen 8 are shown in FIGS. 2 and 3. The screen 8 shown in FIG. 2 has a large number of circular holes 8a, 8a, . . . formed in a disk, and the diameters of the holes 8a, 8a, . In FIG. 3a, a large number of slit-like through holes 8b, 8b, . . . are formed in a disc, and the width of the through holes 8b, 8b, . Figures b and c show slit-shaped through holes 8.
b, 8b, . FIG. 4 shows through holes 8a and 8b of the screen 8.
Examples of cross-sectional shapes are shown below. Figures a to c show cases in which the cross-sectional area of the through holes 8a and 8b expands with respect to the flow of the mixture pushed out from the bottom to the top in the figures.
When the same figure a is expanded linearly, the same figure b and c
1 and 2 respectively show cases of curved expansion. On the other hand, d, e, and g in the figure are cases in which the cross-sectional area of the through holes 8a and 8b decreases with respect to the flow of the mixture, contrary to the above a to c. Furthermore, FIGS. 5 and 8 show cases in which the cross-sectional areas of the through holes 8a and 8b are once reduced and then enlarged from the middle. As shown in FIGS. 1 and 2, these disk-shaped screens 8, 8... are connected to the stirring plates 7, 7... via spacers 9, 9... on the shaft 6 disposed in the container 4. They are fixed alternately, and the tip of the shaft 6 is fixed by tightening a bolt 19. Then, an uneven strip 21a is formed on the inner periphery of the stirring plate 7 by knurling or the like, and an uneven strip 21b matching the uneven strip 21a is formed on the shaft 6 at each interval at which the stirring plate 7 is fixed. are formed, and by meshing these, the rotation of the motor 5 is transmitted via the shaft 6 to the stirring plates 7, 7...
is transmitted to. On the other hand, screens 8, 8
..., these uneven lines do not mesh with each other, and the motor 5
rotation is not transmitted. Furthermore, screen 8,8
The outer peripheral edges of the spacers 10, 10, . Therefore, although the stirring plates 7, 7, . . . are rotationally driven by the motor 5, the screen is not rotated and remains stopped. The screens 8, 8 fixed vertically inside the container 4 allow the inside of the container 4 to be controlled by each stirring plate 7, 7.
It is divided into 16, 16... rooms. The table below shows the square shape of the magnetic film surface obtained by dispersing magnetic paint for magnetic recording tape using a dispersion machine according to the present invention, and then manufacturing magnetic recording tape using the conventional method under the same conditions. The figure shows the dispersion time required for the ratio to reach 0.85. That is, a resin binder is used as the dispersion medium of the mixture, Co-Cr magnetic powder is used as the dispersoid, and fine granules with a particle size of 1.5 to 3 mm are used as the media.
The mixture of the dispersion medium and dispersoid is pumped 3 times by pump 3.
The mixture was pressurized to a pressure of Kg/cm ² and introduced into container 1 for dispersion. Then, the magnetic paint is extracted from the container 4 every hour, and a magnetic tape is manufactured from it by the doctor blade method.
The dispersion time required for Bs to reach 0.85 is calculated and shown. The following table shows the screen 8 as shown in Fig. 4, which has a circular hole with a minimum diameter of 1.0 mm.
A screen 8 having a cross section of through holes 8a as shown in Figures a to h is used. On the other hand, the Comparative Example column shows the case where a disperser as shown in FIG. 5 was used in which the inside of the container 4 was not divided into stirring plates 7, 7, . . . by the screen 8. That is, the dispersion time required for the squareness ratio of the magnetic film surface of a magnetic recording tape manufactured under the same conditions as above using the magnetic paint dispersed using this disperser to be 0.85 is shown.

[Table] As is clear from the above table, in Examples 1 to 4 using the dispersing machine according to the present invention, a high squareness ratio was obtained in a shorter dispersion time than in the comparative example using a conventional dispersing machine. It is known that the squareness ratio of the magnetic film surface largely depends on the state of dispersion of magnetic powder in the binder in the magnetic paint. That is, when the apparatus according to the embodiment of the present invention was used, a magnetic paint with a higher degree of dispersion was obtained in a shorter time than in the comparative example. [Effects of the invention] As explained above, the disperser according to the invention has the following effects:
During the operation, the media in the container 4 can be maintained in a uniformly distributed state, making it possible to maintain high dispersion ability throughout. This has the effect of enabling efficient and reliable dispersion of the mixture. Furthermore, since the screen 8 increases the dispersion ability of the mixture, more uniform dispersion becomes possible in a short time.

[Brief explanation of drawings]

Figure 1 is a piping and cross-sectional view of a disperser showing an embodiment of the present invention, Figure 2 is an exploded perspective view showing the main components of the disperser, and Figure 3 is a cross-sectional view of the disperser used in the disperser. FIG. 4 is a perspective view showing various configurations of the screen, FIG. 4 is a cross-sectional view of main parts showing various cross-sectional shapes of the through holes of the screen, and FIG.
The sectional view and FIG. 6 are exploded perspective views showing the main components of the disperser. 4... Container, 6... Shaft, 7... Stirring plate,
8... Screen, 8a... Screen hole,
14...Inlet, 15...Outlet, 16...Divided room.

Claims (1)

[Scope of utility model registration request] an inlet 14 for introducing the mixture into the container 4 under pressure;
A viscous mixture dispersion is provided with a discharge port 15 for discharging the mixture to the outside of the container 4, and a stirring plate 7 driven to rotate to stir the mixture and granular media in the container 4. In the machine, the inside of the container 4 is divided into a plurality of vertically divided chambers 16 including the stirring plate 7 by a screen 8, and the screen 8 has a plurality of chambers 16 that allow only the mixture to pass through and block the passage of the media. A viscous mixture dispersing machine characterized in that it has through holes 8a and 8b, and the cross-sectional area of the through holes 8a and 8b changes along the moving direction of the mixture passing therethrough.