JPH0478341B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention involves rotating a casing at high speed to press a material to be treated against the inner circumferential surface of the casing, and powder formed on the inner circumferential surface of the casing by the pressing. The present invention relates to a powder processing method for applying compressive force and shear force to a body layer using friction pieces, and an apparatus used therein.

[Conventional technology]

Conventionally, in the above-mentioned powder and granule processing method, the powder and granule were processed only by compression and shearing action by friction pieces, and the powder and granule were ultra-finely pulverized.

[Problem to be solved by the invention]

However, powder and granules are effectively used in various fields as new materials, and for this reason, there is a need for means that can effectively achieve mixing, granulation, spheroidization, coating, and encapsulation of powder and granules. The body processing method could not meet this demand.

On the other hand, mixing of powder and granular materials, which has been conventionally carried out,
All methods of granulation, spheroidization, coating, and encapsulation have the following drawbacks.

(b) With methods of finely mixing premixed powder and granules using screen mills, ball mills, etc., although pulverization progresses, microscopic dispersion is poor, making it difficult to achieve highly accurate and uniform mixing; Furthermore, even once mixed, separation is likely to occur due to the difference in specific gravity.

(b) With the method of granulating powder and granules as they roll in a rotating casing, it is difficult to obtain fine granules of 50 μm or less, and the granules have weak binding strength.

(c) The method of heating and melting pellets to form a sphere is limited to pellets with a low melting point and a shape close to a sphere, and cannot be applied to powder particles with a whisker-like shape or a different diameter shape.

(e) Coating and encapsulation methods that attach powder to the surface of granules include covering the surface of fine powder of about 1 to 50 μm with ultrafine powder of about 0.001 to 5 μm, and obtaining, covering the surface of the fine powder with a colloidal substance,
It is not possible to encapsulate a low-temperature vaporized substance in an encapsulant.

The object of the present invention is to improve the powder and granule processing method described at the beginning, to enable mixing, granulation, spheroidization, coating, and encapsulation, and to eliminate the drawbacks of the conventional means described above. It is in the point of doing.

[Means to solve the problem]

The characteristic means of the powder and granular material processing method according to the present invention is to rotate the casing at high speed to press the material to be treated against the inner circumferential surface of the casing, and as a result of the pressing, friction pieces are formed on the powder layer formed on the inner circumferential surface of the casing. A granular material processing method in which compressive force and shear force are applied by means of a scraping piece, wherein a scraping action, a dispersion action, and an agitation action are applied to the powder layer on the inner circumferential surface of the casing, and the scraping action and the dispersion action are applied to the powder layer on the inner circumferential surface of the casing, The purpose is to perform any one of mixing, granulation, spheroidization, coating, and encapsulation on the material to be treated by the cooperative action of the pieces, and the effects are as follows.

[Effect]

It was confirmed through experiments that the material to be treated is strongly pressed against the inner peripheral surface of the casing using the centrifugal force generated by the high-speed rotation of the casing, and strong compressive force and shearing force are applied to the powder layer formed by the friction pieces. By combining and repeatedly applying the scraping action, dispersion action, and stirring action using the scraping pieces to the powder layer treated with the friction pieces, mixing, granulation, spheroidization, and We were able to confirm that coating and encapsulation are possible, and that these processes can be achieved in a manner superior to conventional techniques.

Further details of each process are as follows.

(b) Mixing We were able to reliably achieve highly accurate mixing that was sufficiently uniform not only macroscopically but also microscopically.

This is due to the synergistic effect of the strong compressive force and shearing force of the friction pieces to sufficiently pulverize the material to be treated, and the scraping pieces to provide sufficient overall dispersion and agitation. It is assumed that there is.

(b) Granulation By adding a small amount of water, oil (liquid), or a low-melting point substance, or by applying heat as necessary, various materials to be treated can be made into particles of 50 μm or less. Microgranules could be easily obtained, and granules with sufficiently strong bonding force could be reliably obtained regardless of the particle size.

It has been found that the slower the rotation of the casing, the larger the shape of the granules becomes, and the longer the processing time, the larger and more spherical the granules become.

(c) Spheronization It was possible to sufficiently spheroidize various shapes of treated materials, such as whisker-like or spongy organic polymers, and synthetic resins with different diameters, and the range of application was sufficiently expanded.

(d) Coating or encapsulation The surface of fine powder of about 1 to 50 μm made of organic polymers and inorganic substances such as silica is coated with titanium oxide,
It was possible to easily obtain fine particles covered with fine powder of about 0.001 to 5 μm consisting of iron oxide, pigments, and other inorganic or organic substances, or a composite of fine powders.

The reason for this is that high-precision mixing is achieved as described in the mixing section (a) above, and the surface of the fine powder or ultra-fine powder is activated by the strong shearing force caused by the friction pieces. It is presumed that the resulting fine powders and ultrafine powders are strongly compressed and rubbed against each other by friction pieces, resulting in strong mechanochemical bonding and the formation of composite particles. Furthermore, when one of the treated materials to be mixed with each other is a high-molecular organic substance, the high-molecular organic substance is softened by the action of the friction piece, and the other treated material is pushed into the softened high-molecular organic substance, so that the coating It is assumed that encapsulation can be realized.

When a colloidal substance (liquid) is added to fine powder,
A fine powder can be coated with a colloidal substance, and if necessary, it can be heated to achieve a good coating, and if necessary, it can be dried or heated and melted and cooled to achieve a good coating. Good encapsulation was achieved.

Encapsulating fragrances in cyclodextrin, etc.
The low-temperature vaporized substance could be encapsulated in the capsule material.

〔Effect of the invention〕

As a result, extremely high-precision mixing, fine or strongly bonded granulation, spheroidization that is not limited by the shape of powder or granules, coating or encapsulation by mixing fine powders, and mixing fine powders and colloidal substances. We have established a convenient powder processing method that can successfully carry out various powder processing methods such as coating and encapsulation, and encapsulation in which a low-temperature vaporized substance is enclosed in an encapsulating material.

By providing the granular material processing apparatus according to claim 5, the above-mentioned excellent granular material processing can be carried out easily and reliably.

〔Example〕

Next, an example will be shown with reference to FIGS. 1 and 2.

A low cylindrical casing 4 forming a processing chamber 3 is attached concentrically to the upper end of a vertical rotating shaft 2 attached to a base 1, and an electric motor 5a and a transmission 5b are attached.
A drive device 5 consisting of the like is connected to the lower end of the rotating shaft 2 to drive and rotate the casing 4 so that the material to be treated inside the casing 4 is pressed against the inner circumferential surface 4a of the casing by centrifugal force. The rotation speed of the casing 4 is configured to be adjustable so that an appropriate centrifugal force can be obtained depending on the properties of the material to be treated.

The casing 4 is surrounded by a cover 7, and a fan 12 is connected to the lower part of the casing 4 to close the cover 7.
The structure is such that outside air is sucked in through an intake port 13 formed in the casing 4 and the casing 4 is cooled by the sucked outside air, and the sucked outside air is guided to a conveyance channel 10 connected to the cover 7 as a gas for conveying the processed material. It is structured as follows.

In order to transfer the processed material from the processing chamber 3 to the cover 7 side, the upper center of the casing 4 is opened to form an overflow type discharge port 11 for the processed material.

A weir 21 is provided to regulate the delivery of the processed material from the discharge port 11, and by lowering the weir 21, the discharge port 1
1 can be closed. That is, by closing the discharge port 11 with the weir 21, closing the conveyance channel 10, removing the fan 12, and performing cooling or heating with a jacket or the like, which will be described later,
Batch operation of this device is possible. In this case, the material to be treated is taken out by inserting a pipe connected to an external suction device into the processing chamber 3 after the operation is stopped, and using suction force.

A conical portion 8c fixed to the upper end of the rotating shaft 8a concentric with the rotating shaft 2 is provided in the casing 4, and a support body 8b attached to the conical portion 8c has a distal end thereof.
A friction piece 9a that applies compressive force and frictional force to the material to be treated in cooperation with the inner circumferential surface 4a of the casing, and a scraping piece 9b that imparts a scraping action, a dispersion action, and a stirring action to the material to be processed are attached. , a friction piece 9a and a scraping piece 9b are arranged at appropriate intervals in the direction of rotation of the casing 4.
are arranged in the processing chamber 3. The friction piece 9a is formed with an inclined surface such that the distance between the friction piece 9a and the casing 4 becomes narrower toward the rotation direction of the casing 4, and the scraping piece 9b has an inclined surface formed such that the distance between the scraping piece 9b and the casing 4 becomes wider toward the rotation direction of the casing 4. The working surface is formed into a wedge shape or a comb-like shape that becomes wider toward the casing four rotation direction side.

Inside the rotating shaft 8a, there are a support 8b, a friction piece 9a,
A passage 27 for allowing heating and cooling medium to flow into the scraping piece 9b is formed, and the rotary joint 2
A storage tank 26 for a heating medium is connected to the channel 27 via a line 4 .

The rotating shaft 8a is interlocked with the drive device 5 so that the friction pieces 9a and the scraping pieces 9b rotate relative to each other with a constant rotational difference or a constant speed difference with the casing 4. In other words, the friction piece 9a and the scraping piece 9
b is driven and rotated in the same direction around the coaxial core of the casing 4 at a slightly slower speed, and the friction piece 9a is applied to the powder layer formed on the inner circumferential surface 4a of the casing.
The structure is such that the scraping piece 9b is activated.

Note that the rotation of the friction pieces 9a and the scraping pieces 9b can be stopped if necessary, and the relative speed can be increased to increase the stirring force. The friction piece 9a and the scraping piece 9b can be appropriately changed in shape, material, number of installed pieces, etc.

At the center of the cover 7, a path 6 for supplying the material to be treated downward toward the conical portion 8c is formed by attaching a pipe 14, and at the top of the cover 7,
A nozzle 22 for supplying water, oil, etc. toward the inner peripheral surface 4a of the casing, and a suction pipe 23 for suctioning and discharging the material to be treated that has accumulated inside the casing 4 are attached. , jacket 2 for passing medium such as heating or cooling gas, liquid, etc.
5 is formed.

As ancillary equipment when this device is operated continuously, a collector 15 and an exhaust fan 16 are installed in the flow path 10 in that order.
The discharge port of the collector 15 is connected to the supply path 6 by a rotary feeder 17, so that partially untreated materials can be reprocessed.

A blower 18 that supplies an appropriate amount of heated and cooled air or inert gas as necessary, a feeder 19 for supplying the material to be processed, and a feeder 20 that supplies the material to be processed processed in another process are connected to the supply route 6. It is configured so that a supply form can be adopted depending on the condition of the material to be processed.

The gas to be sent to the cover 7 can be appropriately selected depending on the material of the material to be treated, and an appropriate air supply means can be used depending on the type of gas, such as an electric blower or a pressurized gas cylinder. The means are collectively referred to as an air supply device 12.

You can freely change the incidental equipment as a processing device, such as the equipment for supplying processed materials to the processing chamber 3 and the equipment for recovering processed materials.
Can be added or omitted.

[Another example]

The processing device may be of horizontal arrangement with a horizontal or inclined axis of rotation.

The friction piece may be a roller, in which case
By rotating the roller relative to the inner circumferential surface 4a of the casing, the same effect as that of the friction piece 9a can be obtained.

In addition to supplying heated or cooled air or inert gas into the processing chamber 3, a refrigerant such as liquid nitrogen may be directly introduced into the casing 4 for the purpose of cooling the processing chamber 3.

The present invention can be used in a wide variety of fields, such as paints, powder coatings, pigment glazes, toners, printing/transfer materials, foods, feeds, fertilizers, pharmaceuticals, industrial chemicals, ultraviolet sterilization, and sterilizing materials. , deodorizer,
Used in fragrances, cosmetics, clothing, cement, mold release agents, resin molding materials, paper manufacturing additives, electromagnetic wave absorbers, far-infrared ray materials, anti-static adjusters, disk materials, liquid crystal materials, etc., as well as standard powders. can.

[Experiment example]

Experimental examples are described below.

Experimental example 1 Titanium oxide with a particle size of 0.01 to 0.2 μm and an average particle size
When 0.005μm ferric oxide was mixed with the above-mentioned device at a mixing ratio of 1:99, a mixture was obtained that did not separate even in water or oil, and did not separate even after long-term storage, and was useful for pigments, cosmetics, etc. It was found that it can be used for mixing and blending ingredients, etc.

Experimental Example 2 Ultrafine mica powder, titanium oxide, alumina, silicon oxide, and colloidal silica were granulated using the above-mentioned apparatus and dried at 180 to 250°C. The particle size and blending ratio of the materials are as follows.

Ultrafine mica powder Average particle size 0.6μm 40% Titanium oxide 〃 0.1μm 15% Alumina 〃 0.1μm 5% Silicon oxide〃 0.05μm 20% Colloidal silica 〃 0.015μm 20% (solid content concentration 20%) As a result, Figure 3 As shown in Figure 2, spherical granules with a diameter of 1 to 100 μm were obtained, and it was found that they could be used for pigments, paints, cosmetics, standard powders, etc.

Experimental Example 3 As shown in Figure 4, anisotropic, spongy, and whisker-shaped tetrafluoroethylene resin with a size of 20 to 100 μm was spheronized using the above-mentioned apparatus, and after 5 minutes, it became spherical as shown in Figure 5. It became spherical and elliptical with a size of 10 to 30 μm, and after 40 minutes, it became an ellipse and a circle with a size of 30 to 60 μm as shown in FIG. 6, and it was found that it could be used for resin molding materials, toners, etc.

Experimental example 4 Polyamide resin spheres with a particle size of 3 to 15 μm and a particle size of 0.1 to 15 μm
When 0.2 μm titanium oxide powder was coated with the above-mentioned device under electrostatic charge and heating, a coating material as shown in FIG. 7 was obtained, and it was found that it could be used in cosmetics and the like.

Experimental example 5 Silicone resin spheres with an average particle size of 2 μm
To coat the 0.015 μm titanium oxide, first the surface of the silicone sphere was activated by rubbing with the above-mentioned device, and then the titanium oxide was put into the above-mentioned device, and the coating material as shown in Figure 8 was formed. The hydrophobic silicone properties were changed to hydrophilic properties.

Experimental Example 6 The surface of the coating material obtained in Experimental Example 5 was further coated with iron oxide using the above-mentioned apparatus. Iron oxide uses fatty acids as a dispersant and has an average particle size of
It is 0.005 μm.

As a result, a coating material as shown in Figure 9 was obtained, and the material that had become hydrophilic due to the titanium oxide coating returned to hydrophobic properties and increased oil absorption, making it useful for use in cosmetics, mold release agents, etc. It was found that it can be used for pigments, etc.

Experimental Example 7 When titanium oxide with an average particle size of 0.015 μm was coated on the surface of polymethyl methacrylate spheres with an average particle size of 6.7 μm using the above-mentioned apparatus, a coating material as shown in FIG. 10 was obtained.

In other words, the temperature of the casing exceeds the glass transition point of polymethylmethacrylate, and the surface temperature of polymethylmethacrylate rises to 200℃ due to friction.
When it reaches close range, a kneading effect with titanium oxide begins to occur at the surface portion, and as the operation continues, the titanium oxide diffuses into the interior of the polymethyl methacrylate, and as a result, the above-mentioned coating material is obtained. It has been found that the above coating is a highly dispersible spherical particle with a negative electrostatic charge and zero angle of repose, and can be used as cosmetics, toners, pigment bases, paints, standard powders, etc.

[Brief explanation of drawings]

1 and 2 show an embodiment of a powder processing apparatus according to the present invention, FIG. 1 is an overall conceptual diagram, and FIG. 2 is a sectional view taken along the line -- in FIG. 1. Figures 3 to 10 are micrographs of materials obtained in experimental examples of the present invention. 3... Processing chamber, 4... Casing, 4a... Casing inner peripheral surface, 5... Drive device, 9a... Friction piece, 9b... Scraping piece.

Claims (1)

[Claims] 1. The casing 4 is rotated at high speed to press the material to be treated against the inner circumferential surface 4a of the casing 4, and the powder layer formed on the inner circumferential surface 4a of the casing due to the pressing is coated with the friction piece 9a. A method for processing powder and granular material that applies compressive force and shearing force, the scraping action, dispersion action, and stirring action being applied to the powder layer on the inner circumferential surface 4a of the casing by means of scraping pieces 9b, and the friction pieces 9a and the scraping piece 9b to perform any one of mixing, granulation, spheroidization, coating, and encapsulation on a material to be treated. 2. The powder processing method according to claim 1, wherein a liquid agent is added to the material to be processed during any one of the granulation, coating, and encapsulation treatments. 3. The powder processing method according to claim 1 or 2, wherein the material to be processed is heated during the granulation or coating treatment. 4. Heating the material to be treated during the encapsulation,
The method for processing powder or granular material according to claim 1 or 2, wherein the method is followed by cooling. 5. A casing 4 forming a processing chamber 3 is rotatably provided, and a drive device 5 is provided for rotating the casing 4 at high speed so that the material to be processed inside the casing 4 is pressed against the inner circumferential surface 4a of the casing by centrifugal force. A powder and granular material processing device in which a friction piece 9a that applies compressive force and shear force to the powder layer on the inner circumferential surface 4a is rotatably provided relative to the inner circumferential surface 4a of the casing, the inner circumferential surface of the casing A scraping piece 9 that imparts a scraping action, a dispersion action, and an agitation action to the powder layer on the surface 4a.
b is provided to be rotatable relative to the inner circumferential surface 4a of the casing. 6. The granular material processing apparatus according to claim 5, wherein the casing 4, the friction piece 9a, and the scraping piece 9b have a mechanism for heating and cooling. 7 The working surface of the scraping piece 9b is formed into a wedge-like or comb-like shape in which the distance from the inner circumferential surface 4a of the casing and the width of the working surface become larger toward the relative rotation direction of the casing 4. Claim 5
Or the powder processing device according to 6.