JP6505523B2 - Plasma powder processing apparatus and plasma powder processing method - Google Patents

Description

  The present invention relates to a plasma powder processing apparatus and a plasma powder processing method for reforming the surface of powder fine particles.

  In recent years, in the industrial field dealing with metals, carbon, resins, ceramics, etc., the demand for powder fine particles (hereinafter, also simply referred to as “powder”) to which various functions have been added is becoming stronger. In order to meet the demand, development of precise and high-quality surface modification technology of modifying the surface of powder fine particles uniformly on the nano level has been actively conducted.

  One of such surface modification techniques could not be achieved by conventional physicochemical modification, which is a plasma treatment technique for modifying the surface by bringing the plasma into contact with the surface of the powder to be treated. It is noted as a surface modification technology that enables precise and high quality modification.

  Then, as such plasma processing technology, after generating plasma by glow discharge in a gas atmosphere mainly composed of helium (He), the plasma is supplied to the atmosphere and brought into contact with powder, thereby generating plasma. Atmospheric pressure plasma treatment techniques have been proposed to treat the powder to perform surface modification of the powder (for example, Patent Documents 1 to 3).

Unexamined-Japanese-Patent No. 2010-29830 JP, 2010-29831, A JP-A-7-328427

  However, the above-described atmospheric pressure plasma processing technology can not avoid the occurrence of the following problems, and a new processing technology that replaces the atmospheric pressure plasma processing technology has been desired.

  That is, since the plasma generated in the atmospheric pressure plasma processing technology has a high temperature, it is not possible to process powder having low heat resistance such as resin, and the powder to be treated is limited.

  Further, as described above, since the generation of plasma is performed under a gas atmosphere mainly composed of He gas, the processing content is limited, and the characteristics that can be imparted to the powder are limited. And since it is necessary to use a large amount of expensive He gas at the time of processing, it can not necessarily be said that it is a practical technique.

  Under these circumstances, the inventor focused on the reduced pressure high frequency plasma processing technology as a new processing technology replacing the atmospheric pressure plasma processing technology.

  That is, the low pressure high frequency plasma is a so-called low temperature plasma, and among the atoms and molecules of the gas and the electrons and ions generated by ionization, only the electrons become high temperature (several tens of thousands of degrees) and the molecules, atoms and ions of the gas are It maintains a low temperature condition close to room temperature. Therefore, the present invention can be applied to surface modification of powder having low heat resistance, such as resin, with less thermal damage to the object to be treated.

In addition, by utilizing the high energy of electrons to excite and ionize only specific atoms and molecules, the reforming reaction on the powder surface can be performed at a low temperature. Then, as a gas used in the process, in addition to He gas, Ar, H ₂ , N ₂ , NH ₃ , CF ₄ , CHF ₃ , C ₂ F ₆ , SF ₆ , H ₂ O, O ₂ gas, etc. It can be used. Moreover, you may mix and use 2 or more types of said gas.

  For these reasons, in the case of using reduced-pressure high-frequency plasma, various surface modifications can be performed precisely and with high quality for a large number of types of powder.

  However, since this reduced-pressure high-frequency plasma processing is a technique for bringing the reduced-pressure high-frequency plasma into contact with the surface of each powder contained in the chamber to perform the reforming treatment, among the powders contained in the chamber, The generated plasma does not sufficiently reach the powder in the lower layer, and the surface of the powder can not be in sufficient contact with the plasma. As a result, a difference occurs in the surface modification treatment between the powder on the surface and the powder on the lower layer.

  Therefore, the powder is taken out from the chamber and stirred every time one treatment is finished, dividing the treatment into a plurality of times so as not to cause such a difference in treatment, or reducing the treatment amount per time The plasma is easily brought into contact with the whole of the stored powder. However, since it is difficult to process a large amount of powder efficiently with such a processing method, reduced-pressure high-frequency plasma processing is currently limited to laboratory level technology, and it can be said that it is still a practical technology. Absent.

  Therefore, it is an object of the present invention to provide a plasma powder processing apparatus and a plasma powder processing method capable of efficiently performing reduced pressure high frequency plasma processing capable of precise and high quality surface modification with high mass productivity. Do.

  When the existing plasma powder processing apparatus is used to process the powder by low-pressure high-frequency plasma, as described above, the surface modification process has a difference between the powder in the surface layer and the powder in the lower layer, It has been an obstacle to mass producing powder that has been precisely and high quality powder processed.

  Therefore, if the present inventor can stir the powder during the above-described reduced pressure high frequency plasma processing, the difference in processing does not occur in the entire powder stored in the chamber, and a large amount of powder is efficiently processed. As a plasma powder processing apparatus suitable for this purpose, we focused on a barrel type plasma processing apparatus conventionally used for etching a wafer.

  That is, since the barrel-type plasma processing apparatus has a cylindrical chamber disposed sideways, powder is stored in the cylindrical chamber during plasma processing, and the central axis of the chamber is the rotation center. If it was possible to rotate, it was thought that the whole of the powder stored in the chamber could be easily stirred.

  However, when trying to rotate the chamber of such a barrel type plasma processing apparatus, since the electrode for generating plasma is closely attached to the outer peripheral surface of the chamber, this electrode also rotates in accordance with the rotation of the chamber. It has to be done and it can not be applied as it is.

  Therefore, it was considered to separate the electrode from the chamber and rotate only the chamber, but in this case, since a layer of air is formed between the chamber and the electrode, the high frequency is not transmitted into the chamber and plasma is generated. I can not do it. Next, a means for rotating the chamber without interposing the atmosphere between the electrode and the chamber was examined.

  As a result, instead of rotating the chamber itself, a powder storage container having a cylindrical shape and configured to be able to store powder therein is provided in the chamber, and plasma is generated in the chamber and the powder storage container. It was conceived to rotate this powder container while supplying a gas for generation.

  As described above, even if a large amount of powder is used, plasma can be efficiently generated by rotating the powder storage container while allowing the chamber to stand and performing plasma processing while stirring the powder. It is possible to provide a mass-produced powder that has been treated and surface-modified with high precision and quality.

  However, even if the plasma treatment is performed using the above method, if the powder comes in contact with the atmosphere when taking out the treated powder from the powder storage container to the outside, depending on the type of powder and the treatment content In this case, the reformed characteristics may be deteriorated, and the desired reforming effect may not be obtained. In particular, the fine powder particles have a large specific surface area, are active, and are rich in reactivity, so there is a high possibility that the reforming effect will be impaired even if they are brought into contact with the air for a short time. Further, since the powder storage container is provided with a supply port for supplying a gas for generating plasma into the powder storage container, when the chamber is opened, air may intrude into the storage container.

  Then, as a result of examination, the present inventor made it possible to put the powder container into and out of the chamber, and when taking out the powder after the treatment, the powder container and the periphery of the chamber were kept in a reduced pressure atmosphere. Every chamber was removed from the chamber.

For example, after taking out the powder storage container while maintaining the inside of the chamber and the inside of the powder storage container in a reduced pressure atmosphere, the periphery of the powder storage container is purged to an atmospheric pressure with an inert gas to obtain an inert gas atmosphere. A means (non-air contact means) is provided to prevent the treated powder from coming into contact with the atmosphere. Then, the powder is transferred to a storage sealed container under an atmosphere not in contact with the atmosphere, and then the sealed container in which the powder is sealed is taken out of the atmosphere. Thereby, the plasma-treated powder can be recovered without being exposed to the atmosphere.
If the present inventor can appropriately switch between the above-described counter electrode discharge method, RIE electrode discharge method, and PE electrode discharge method, one plasma powder processing apparatus has optimal conditions for various applications. It was thought that the surface modification treatment of the powder could be performed below. Then, since there are many parts common to these three types of electrode discharge methods, it has been thought that it can be realized by appropriately switching the connection of the high frequency power and the ground to the electrodes.
That is, the first and second external electrodes are provided on the outer peripheral surface of the chamber so as to face each other, and rod-like internal electrodes are provided in the powder storage container, and the above-mentioned facing is achieved by changing the connection of these electrodes appropriately. The electrode discharge method, the RIE electrode discharge method, and the PE electrode discharge method can be appropriately switched.
Specifically, by using one of the first and second external electrodes as an electrode for applying high-frequency power and the other as an electrode for grounding, an electrode of a counter electrode discharge type can be obtained. Then, by setting both or one of the first and second external electrodes as an electrode for applying high frequency power and an electrode for grounding the internal electrode, an electrode of the RIE electrode discharge system can be obtained. Further, by using the electrode for grounding the first and second external electrodes and the electrode for applying the high frequency power as the internal electrode, it is possible to obtain an electrode of the PE electrode discharge system.
As described above, the reduced-pressure high-frequency plasma is generated by the electrode discharge method suitable for the purpose of modification from among the counter electrode discharge method, the RIE electrode discharge method and the PE electrode discharge method in one plasma powder processing apparatus. Since the plasma processing can be performed, the installation space and installation cost of the plasma powder processing apparatus can be reduced.

The inventions described in claim 1 and claim 2 are based on the above findings, and the invention described in claim 1 is
A horizontally oriented cylindrical chamber,
A cylindrical powder container which can be taken in and out from one side of the chamber and can contain powder therein;
Pressure reducing means for holding the inside of the chamber and the powder container at a pressure lower than atmospheric pressure;
A gas supply means for supplying a gas for plasma generation into the chamber and the powder container;
An electrode for generating reduced-pressure high-frequency plasma by the gas for plasma generation in the chamber and the powder container;
A rotary drive unit configured to rotate the powder storage container with the central axis of the powder storage container as a rotation axis in a state where the powder storage container is placed in the chamber;
The powder stored in the powder storage container is subjected to plasma processing while rotating the powder storage container in a state where the powder storage container is placed in the chamber ,
As the electrodes, first and second external electrodes are provided facing each other on the outer peripheral surface of the chamber, and rod-shaped internal electrodes are provided in the powder storage container,
A switching means for switching the electrode to any one of a counter electrode discharge type electrode, a reactive ion etching electrode discharge type electrode and a plasma etching electrode discharge type electrode;
The switching means is
When the electrode of the counter electrode discharge system is used, any one of the first and second external electrodes is an electrode to which high frequency power is applied, and the other is an electrode to ground.
When the electrode of the reactive ion etching electrode discharge system is used, both or one of the first and second external electrodes is an electrode for applying high frequency power, and the internal electrode is an electrode for grounding.
When it is set as the electrode of the said plasma etching electrode discharge system, it is an electrode which grounds the said, 1st and 2nd external electrode, It is a switching means which makes the said internal electrode an electrode which applies high frequency electric power. It is an apparatus.

And the invention according to claim 2 is
The plasma powder processing apparatus according to claim 1, further comprising an atmospheric non-contact means for preventing the chamber and the powder container from coming into contact with the atmosphere.

  Next, the inventor examined electrodes and circuits for generating reduced-pressure high-frequency plasma in each of the above-described plasma powder processing apparatuses. As a result, it is possible to apply various discharge methods when plasma treating the powder stored in the powder storage container while rotating the powder storage container with the powder storage container placed in the chamber. It turned out that there is.

  The first is a counter electrode discharge method. In this case, the first and second external electrodes are provided opposite to each other on the outer peripheral surface of the chamber, and one of the electrodes is set to the electrode to which high frequency power is applied and the other is set to the ground Be done. As a result, an isotropic reduced-pressure high-frequency plasma can be generated, and the surface of the carbon nanoparticles can be modified to impart good hydrophilicity.

  The second is a reactive ion etching (RIE) electrode discharge method. In this case, an external electrode is provided on the outer peripheral surface of the chamber as an electrode to which high frequency power is applied, and a rod-like internal electrode is provided in the powder container as an electrode grounded. As a result, a sheath region in which highly active ions or radicals having anisotropy and high-speed oscillation that vibrate at high speed exist is formed on the external electrode side in the powder storage container, and the powder is formed in this sheath region. Since it can be treated, it can be preferably applied to surface treatments that require high reactivity.

  In the RIE electrode discharge method, if the external electrode covers the entire circumference of the outer peripheral surface of the chamber, the anisotropy and activity of the sheath region are weakened, so application to a surface treatment in which too high reactivity is undesirable be able to.

  On the other hand, in the RIE electrode discharge method, when the external electrode covers only a part of the outer peripheral surface of the chamber, the anisotropy and activity of the sheath region are enhanced, so that high reactivity is applied to the surface treatment preferable. Can.

  The third is a plasma etching (PE) electrode discharge method. In this case, an external electrode is provided on the outer peripheral surface of the chamber as an electrode to be grounded, and a rod-like internal electrode is provided in the powder container as an electrode to which high frequency power is applied. Thus, unlike the case where the above-described RIE electrode discharge method is applied, powder processing is performed outside the sheath region, so that the powder is less damaged and the powder can be uniformly processed.

The inventions according to claims 3 to 7 are based on the above findings, and the invention according to claim 3 is
The electrode is a counter electrode discharge type electrode,
First and second external electrodes are provided opposite to each other on the outer peripheral surface of the chamber,
The plasma powder processing according to claim 1 or 2, wherein any one of the first and second external electrodes is an electrode to which a high frequency power is applied, and the other is an electrode to be grounded. It is an apparatus.

The invention according to claim 4 is
The electrode is a reactive ion etching electrode discharge type electrode,
An external electrode is provided on the outer peripheral surface of the chamber as an electrode to which high frequency power is applied.
The plasma powder processing apparatus according to claim 1 or 2, wherein a rod-shaped internal electrode is provided in the powder container as an electrode to be grounded.

The invention according to claim 5 is
The plasma powder processing apparatus according to claim 4, wherein the external electrode covers the entire periphery of the outer peripheral surface of the chamber.

The invention according to claim 6 is
The plasma powder processing apparatus according to claim 4, wherein the external electrode covers a part of the outer peripheral surface of the chamber.

The invention according to claim 7 is
The electrode is a plasma etching electrode discharge type electrode,
An external electrode is provided on the outer peripheral surface of the chamber as an electrode to be grounded.
The plasma powder processing apparatus according to claim 1 or 2, wherein a rod-shaped internal electrode is provided in the powder container as an electrode to which a high frequency power is applied.

  Next, in each of the above-described electrode discharge methods, if the gas supply means for supplying the gas for plasma generation also serves as the internal electrode, space saving is achieved, and the gas for plasma generation is more uniform in the powder container. Can be supplied.

The invention according to claim 8 is based on the above,
The plasma powder processing apparatus according to any one of claims 4 to 7 , wherein the gas supply unit also serves as the internal electrode.

  However, in each of the above-described plasma powder processing apparatuses, it has been found that even if the powder storage container is rotated, the powder may not adhere to the wall of the container during the plasma processing and may not be separated, making stirring impossible. The

  Then, after the inventor temporarily stops supply of the gas for plasma generation by the gas supply means for a predetermined period of time, considering that the attached powder can be peeled off from the wall surface by applying some sort of impact. It has been conceived to provide a gas supply control means for resuming the supply of gas for plasma generation.

  That is, when the gas supply was temporarily stopped and then resumed, a rapid pressure change, specifically a differential pressure of about 100 Pa, was instantaneously generated, so a shock wave was generated and attached to the wall of the container. The powder can be peeled off. At this time, when the gas outlet is directed to the wall surface of the container, the powder can be more reliably peeled off, which is preferable.

  It is preferable that the supply and stop of the gas in the gas supply control means be repeatedly performed in a pulse shape, whereby the powder which could not be peeled off by one shock wave can also be peeled off, and the powder is more surely container. The powder can be stirred more efficiently by preventing adhesion to

The inventions described in claim 9 and 10 are based on the above findings, and the invention described in claim 9 is
A gas supply control means is provided for resuming the supply of the gas for plasma generation after temporarily stopping the supply of the gas for plasma generation by the gas supply means for a predetermined time. The plasma powder processing apparatus according to any one of claims 1 to 8 .

And the invention according to claim 10 is
10. The plasma powder processing apparatus according to claim 9 , wherein the gas supply control means repeatedly performs supply and stop of the gas for plasma generation in a pulse shape.

  Moreover, in order to carry out the plasma processing of powder more uniformly, it is preferable that the rotating shaft of a powder storage container is horizontal. By making the rotation axis horizontal, powder can be rotated in a uniformly dispersed state along the rotation axis of the powder storage container, so a large amount of powder is stored in the powder storage container. Even in such a case, the thickness of the layer of the staying powder can be reduced during the treatment, and the powder can be plasma-treated more efficiently.

That is, the invention according to claim 1 1,
A plasma powder processing apparatus according to any one of claims 1 to 1 0, wherein the rotation axis of the powder container is horizontal.

  In the present invention, in order to stir the whole of the powder stored in the powder storage container more efficiently, it is possible to provide lift-up feathers in the powder storage container that lift and drop the powder to a certain extent. preferable.

That is, the invention according to claim 1 2,
The powder container is characterized in that it includes lift-up feathers that lift the powder to a predetermined height in the rotational direction of the powder container and then drop it as the powder container rotates. The plasma powder processing apparatus according to any one of claims 1 to 11.

  Then, by performing powder processing using the above-described plasma processing apparatuses, various surface modifications can be performed on various types of powders precisely, with high quality, and with high mass productivity.

That is, the invention according to claim 1 3,
A claims 1 to plasma powder processing method the powder under reduced pressure high-frequency plasma treatment using a plasma powder processing apparatus according to any one of claims 1 2,
A plasma powder processing method comprising plasma treating a powder stored in the powder storage container while rotating the powder storage container in a state where the powder storage container is placed in the chamber. is there.

And, the invention according to claim 1 4,
After completion of the plasma treatment, a plasma powder processing method according to claim 1 to 3, the chamber and the powder container by the air non-contact means, and recovering the powder so as not to contact with the atmosphere It is.

  According to the present invention, it is possible to provide a plasma powder processing apparatus and a plasma powder processing method capable of performing reduced pressure high frequency plasma processing capable of precise and high quality surface modification with high mass productivity.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the plasma powder processing apparatus which concerns on one embodiment of this invention, (a) is a whole structure, (b) is a figure which shows a plasma processing part typically. It is a figure which shows typically the plasma processing part of the counter electrode discharge system in the plasma powder processing apparatus concerning one embodiment of this invention. It is a figure which shows typically the plasma processing part of the RIE electrode discharge system in the plasma powder processing apparatus concerning one embodiment of this invention. It is a figure which shows typically an example of the external electrode in the RIE electrode discharge system shown in FIG. It is a figure which shows typically another example of the external electrode in the RIE electrode discharge system shown in FIG. It is a figure which shows typically the plasma processing part of the PE electrode discharge system in the plasma powder processing apparatus concerning one embodiment of this invention. It is a figure explaining the plasma powder processing apparatus which can switch three types of electrode discharge systems, a counter electrode discharge system, a RIE electrode discharge system, and a PE electrode discharge system. It is a figure which shows typically the supply method of the gas for plasma generations to a powder storage container in one embodiment of this invention. It is a figure which shows typically the installation method of the powder storage container in a chamber in 1 embodiment of this invention. It is a figure which shows typically the other installation method of the powder storage container in a chamber in one embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is (a) radial direction sectional view which shows the structure of a powder storage container in one embodiment of this invention, (b) It is a longitudinal direction sectional view. In the 1st experiment of an Example, it is a photograph which shows the hydrophilicity evaluation result of Experiment 1, 2 and 5. FIG. In the 1st experiment of an Example, it is a photograph which shows the hydrophilicity evaluation result of test examples 2-4. It is a figure which shows typically four types of electrode discharge systems implemented in the 2nd experiment of an Example. It is a graph which shows the experimental result of the hydrophilization experiment using four types of electrode discharge systems shown in FIG.

  Hereinafter, the present invention will be described based on the embodiments with reference to the drawings.

1. Plasma Powder Processing Apparatus First, the basic configuration of a plasma powder processing apparatus according to an embodiment of the present invention will be described. FIG. 1 is a view for explaining a plasma powder processing apparatus according to the present embodiment, in which (a) shows an entire configuration and (b) schematically shows a plasma processing unit.

  As shown in FIG. 1 (a), the plasma powder processing apparatus 1 includes a cylindrical chamber 2 disposed laterally and a powder storage container 3, which are stored in a box 8. It is isolated from the atmosphere by The powder storage container 3 is slidable along the axial direction of the chamber 2 and is provided so as to be able to be inserted into and removed from the chamber 2. Further, on the outside of the box 8, in order to efficiently convert high-frequency energy into plasma, matching is performed to follow and control the capacity that changes as needed.

  And as shown in FIG.1 (b), the chamber 2 is equipped with the cylindrical body 21 which has a cylindrical shape, and the sealing part 22a which seals one side of the cylindrical body 21. As shown in FIG. The outer peripheral surface of the cylindrical body 21 is provided in close contact with the cylindrical body 21 so that the first outer electrode 51a and the second outer electrode 51b of the high frequency generator face each other, and the first outer electrode 51a Is connected to the high frequency power supply 5 to form an RF electrode (cathode: cathode), and the second external electrode 51 b is grounded to form a GND electrode (anode: anode). By applying a high frequency power to the first external electrode 51 a, a high frequency is generated and passes through the cylindrical body 21 made of a dielectric and is propagated into the chamber 2. In the present embodiment, the shape of the cylindrical tubular body 21 is not limited to a strictly cylindrical shape, but also includes a barrel shape.

  As a dielectric which comprises the cylindrical body 21, quartz glass, borosilicate glass, an alkali free glass etc. are mentioned, for example. In addition to the above-described electrodes, the cylindrical body 21 is also provided with an exhaust device 4 as pressure reducing means for exhausting the air in the chamber 2 to make the pressure lower than the atmospheric pressure. The sealing portion 22a is provided with a gas supply means 7 for supplying a gas for plasma generation into the chamber 2 at the central portion.

  On the other hand, the powder storage container 3 is a cylindrical container made of a dielectric as in the case of the cylindrical body 21, and the central portion at one end side is open and the other end is the cylindrical body 21 of the chamber 2. The sealing portion 22b is connected to the sealing portion 22b that seals the opposite side of the sealing portion 22a. The opening at one end of the powder container 3 is an air supply / discharge port for inserting the rod-like gas supply means 7. The shape of the powder storage container 3 is not limited to a strictly cylindrical shape like the chamber 2 but includes a barrel shape.

  Further, a rotational drive means 6 is provided at the central portion of the sealing portion 22 b, and the powder storage container 3 can be rotated by the rotational drive means 6.

  When performing plasma processing of powder using the plasma powder processing apparatus according to the present embodiment configured as described above, first, the powder storage container 3 containing the powder is slid to move the inside of the chamber 2 The chamber 2 is sealed by sealing both sides of the cylindrical body 21 with the sealing portion 22a and the sealing portion 22b. Next, after the inside of the chamber 2 is depressurized, a gas for plasma generation gas is supplied from the gas supply means 7 into the chamber 2 and the powder container 3. Then, high frequency power is applied to the first external electrode 51a. As a result, plasma can be generated inside the chamber 2 and the powder storage container 3, and plasma processing of the powder in the powder storage container 3 can be performed.

  Then, while performing the plasma processing of the powder, the powder is stirred by rotating the powder storage container 3 by the rotation driving means 6. As a result, even when processing a large amount of powder when processing the powder with reduced pressure high frequency plasma, the powder can be efficiently stirred and plasma treated, and mass production of high quality powder be able to.

The plasma treatment at this time is performed under known conditions. For example, the plasma can be stably generated by setting the inside of the chamber 2 and the powder container 3 to a pressure lower than the atmospheric pressure (10 ⁵ Pa), preferably 1000 Pa or less, more preferably 500 Pa or less. Further, the frequency of the high frequency power to be applied is appropriately set according to the application etc. For example, radio waves (RF) with a frequency of 3 k to 300 MHz, specifically, high frequencies such as 13.56 MHz, 27.12 MHz, 40.68 MHz etc. It is controlled to occur. In general, control is generally performed to generate a 13.56 MHz high frequency.

After the plasma processing is completed, an inert gas such as nitrogen (N ₂ ) or argon (Ar) is supplied into the chamber 2 and the box 8 to make an inert gas atmosphere, and then the powder storage container 3 is slid. The chamber 2 is taken out of the chamber 2 into the box 8. Then, while the inert gas atmosphere in the box 8 is maintained, the plasma-treated powder is transferred from the powder storage container 3 to the closed container, and then carried out of the box 8. Thereby, the powder can be carried out without being exposed to the atmosphere, and the modification effect of the plasma-treated powder can be prevented from being impaired by the contact with the atmosphere.

2. The electrode discharge method of the plasma powder processing apparatus according to the present embodiment The counter electrode discharge method, the RIE electrode discharge method, the PE electrode method for the generation of the reduced-pressure high frequency plasma in the plasma powder processing apparatus according to the present embodiment described above Three types of electrode discharge methods of the electric method can be applied. Next, the configuration of the plasma processing unit in these electrode discharge methods will be described.

(1) Counter Electrode Discharge Method FIG. 2 is a view schematically showing a plasma processing unit of the counter electrode discharge method. When the counter electrode discharge method is applied, the first external electrode 51a and the second external electrode 51b are disposed on the outer peripheral surface of the cylindrical body 21 so as to face each other, and one first external electrode 51a is connected to the high frequency power supply 5. The other second external electrode 51b is grounded to form an anode.

  When the above-described counter electrode discharge method is used, it is possible to generate isotropic reduced pressure high frequency plasma. The reduced-pressure high-frequency plasma having such isotropy is preferably used in plasma processing for chemically modifying the surface of the processing object. Specifically, in addition to the hydrophilization treatment of nanocarbon particles, it is suitable for surface hydrophilization of resin particles and glass particles. In addition, since processing with high isotropy can be performed, it is suitable when performing plasma processing of the inner surface of a pore such as a porous body to a shape having many holes from the particle surface to the inside.

(2) RIE Electrode Discharge Method FIG. 3 is a view schematically showing a basic configuration of a plasma processing unit of the RIE electrode discharge method. When the RIE electrode system is applied, in addition to the external electrode 51 provided on the outer peripheral surface of the cylindrical body 21, the rod-like internal electrode 52 is inserted inside the powder storage container 3. Then, the internal electrode 52 is grounded to form an anode, and the external electrode 51 is connected to a high frequency power source to be a cathode, so that the powder in the powder storage container 3 can be plasma processed by the RIE electrode system. . The internal electrode 52 in FIG. 3 also serves as the gas supply means 7 and includes a gas flow path for plasma generating gas and a blowout port for blowing out the gas into the powder container 3.

  In the RIE electrode discharge method, as is known, the external electrode 51 is connected to a high frequency power source via a blocking capacitor, and a sheath region (ion sheath) is formed on the external electrode 51 side by a DC bias reaching approximately 1000V. .

  As described above, in this sheath region, ions and radicals vibrate at high speed and have anisotropy, so etching processing, processing of highly reactive particles, and processing from the surface of powder to the depth direction Treatments requiring anisotropy, such as etching of SiC particles and TiN particles with fluorocarbon gas, reduction decomposition treatment of surface oxide film of copper particles and nickel particles, roughening treatment of particle surfaces by physical sputtering effect by anisotropic effect And other plasma processing. In addition, with roughening processing, the surface of the material is roughened at a fine level (nano level), and the surface area of the particles is increased to improve the particle performance (catalytic effect, adhesion, etc.) Say that.

  FIG. 4 and FIG. 5 are views schematically showing examples of the external electrode in the RIE electrode discharge system. When the RIE electrode discharge method is applied, a method (RIE 1) in which the external electrode 51 as shown in FIG. 4 covers the entire periphery of the outer peripheral surface of the chamber 2 and an external electrode 51 as shown in FIG. Two types of methods (RIE 2) in which only a part of the circumferential direction of the outer peripheral surface of 2 is covered (RIE 2) are used.

In the RIE 1 method in which the external electrode 51 covers the entire circumference of the outer peripheral surface of the chamber 2, the anisotropy and the activity of the sheath region are weakened, so that the reaction is somewhat less effective among powder processing requiring high reactivity. It is suitable for processing where the property is desired, for example, plasma processing such as dry chemical etching processing using CF ₄ gas on the surface of SiC particles and TiN particles.

  On the other hand, in the RIE 2 method in which the external electrode 51 covers only a part of the circumferential direction of the outer peripheral surface of the chamber 2, the anisotropy and the activity of the sheath region are enhanced, so powder processing requiring high reactivity Suitable for plasma treatment such as reduction treatment of surface oxide film of copper particles and nickel particles, and roughening treatment of particle surface by physical sputtering effect by strong anisotropy effect. is there.

(3) PE Electrode Method FIG. 6 is a view schematically showing a plasma processing unit of the PE electrode discharge method. When the PE electrode discharge method is applied, basically, an apparatus having the same configuration as the above-described RIE electrode discharge method can be used, but the internal electrode 52 is connected to the high frequency power supply 5 to be a cathode and the external electrode 51 is It differs from the RIE electrode discharge method in that it is grounded to form an anode.

  As described above, in the PE electrode discharge method, the electrode connected to the high frequency power supply 5 and the electrode connected to the ground are the reverse of the RIE electrode discharge method, and when performing plasma processing, the internal electrode connected to the high frequency power supply 5 A sheath region occurs near 52. For this reason, the powder collected on the bottom side of the powder storage container 3 is subjected to plasma processing by plasma in a region other than the sheath region.

  Therefore, the powder is less susceptible to damage, and more uniform processing can be performed. For this reason, the treatment is intended for powder that is easily damaged, and treatment that requires higher quality treatment, such as surface cleaning treatment of barium titanate particles, which is a piezoelectric material and ferroelectric substance, electric damage (charge It is suitable for plasma processing in which it is undesirable to receive damage.

3. Plasma powder processing apparatus with switchable electrode discharge method Next, the above three types of electrode discharge methods can be switched, and one device can appropriately select the electrode discharge method from among the three types of electrode discharge methods The plasma powder processing apparatus that can be used in FIG. 7 is a view for explaining a plasma powder processing apparatus capable of switching between three types of electrode discharge methods, a counter electrode discharge method, an RIE electrode discharge method, and a PE electrode discharge method.

  In the plasma powder processing apparatus shown in FIG. 7, two electrodes of a first external electrode 51 a and a second external electrode 51 b are attached to the outer peripheral surface of the chamber 2, and a rod-shaped inner portion is provided inside the powder container 3. An electrode 52 is inserted.

  In addition, the first external electrode 51a, the second external electrode 51b, and the internal electrode 52 can be connected to the output terminal of the high frequency power supply and the terminal for grounding, respectively, and can not be connected to any terminal. You can also. And although not shown, in this plasma powder processing apparatus, a switch mechanism (switching means) for switching between connection and disconnection of each wire connected to the first external electrode 51a and the second external electrode 51b and the internal electrode 52 Is provided. If a control device is provided in the switch mechanism to automatically switch the electrode discharge method by operating these switches, it is preferable because the occurrence of human error can be prevented and speedy switching can be performed.

  Specifically, in the switch mechanism, the first external electrode 51a and the second external electrode 51b, and the internal electrode 52 are either of the counter electrode discharge type electrode, the RIE electrode discharge type electrode, and the PE electrode discharge type electrode Switch.

  When switching the above-mentioned electrode to the electrode of the counter electrode discharge system, one of the first and second external electrodes 51a and 51b is used as a cathode to apply high-frequency power, and the other as an anode. . And when switching said electrode to the electrode of a RIE electrode discharge system, it is considered as an electrode which applies a high frequency electric power by making both or one of 1st and 2nd exterior electrodes 51a and 51b into a cathode, and grounding the internal electrode 52 as an anode. Electrode. When the above-mentioned electrode is switched to a PE electrode discharge type electrode, the first and second external electrodes 51a and 51b serve as the anode as an anode, and the internal electrode 52 serves as a cathode and applies high frequency power. .

  According to the plasma powder processing apparatus of the present embodiment, the above three types of electrode discharge methods can be switched, and a single device can appropriately select the necessary electrode discharge type from among the above three types of electrode discharge methods. Therefore, the cost for introducing the apparatus can be reduced, and various plasma processes can be realized with one plasma powder processing apparatus.

4. As described above, when the powder storage container 3 is rotated to stir the powder, the powder adheres to the wall surface of the powder storage container 3 during processing depending on the type of the powder, for example. In some cases, it can not be stirred. In order to avoid such a situation, it is preferable to provide a mechanism for peeling off the powder from the wall surface. For such a mechanism, it is preferable to use a shock wave to peel off the powder from the wall.

  Specifically, the supply of the gas for plasma generation by the gas supply means 7 (see FIG. 1) is temporarily stopped for a predetermined time, and then the supply of the gas is resumed, thereby resuming before and after the resumption of the gas supply. A differential pressure of about 100 Pa is generated instantaneously between the two. A shock wave is generated in the chamber 2 due to this differential pressure, and the powder adhering to the wall surface of the powder container 3 can be peeled off while the plasma processing is continued. It is preferable that the gas supply and stop be performed not only once but repeatedly a plurality of times, and the gas is injected in a pulse shape, because the powder can be peeled off more reliably.

  Further, as shown in FIG. 8, for example, when the blowout port is directed horizontally and gas is jetted toward the adhered powder P to make the powder P collide instantaneously, the powder is stored. The powder adhering to the wall surface of the container 3 can be removed more reliably.

5. Installation Method of Powder Storage Container In addition, the installation method of the powder storage container 3 can be changed as appropriate for each processing according to the type of powder and the processing content. Specifically, for example, using a powder storage container whose central portion is formed in a cylindrical shape (barrel shape), as shown in FIG. 9, an installation method for leveling the center of rotation indicated by a broken line; As shown in FIG. 10, the installation method in which the center of rotation indicated by a broken line is inclined with respect to the horizontal is used properly. In this case, the treatment conditions can be changed by making the thickness of the layer of powder stagnating thin by placing horizontally, and making it thick by making it inclined. In FIGS. 9 and 10, reference numeral 31 denotes a central body portion.

  For example, an installation method in which the center of rotation is horizontal is suitable for processing in a short time more uniformly, and an installation method in which the center of rotation is inclined with respect to the horizontal processes plasma powder gently over time. In case it is suitable. Such a change of the installation method can be implemented by changing the inclination angle of the entire plasma processing unit including the powder container sliding mechanism in the box 8 with respect to the horizontal direction.

6. Agitation promotion of powder In order to stir the powder efficiently, it is necessary to lift and drop the powder in the powder storage container 3. However, depending on the type of powder, it may be slippery on the surface of the powder storage container, and in this case, it is difficult to sufficiently stir even if the powder storage container 3 is rotated. In order to cope with such a situation, as shown in FIG. 11, a lift-up wing 34 which extends in the longitudinal direction of the powder storage container 3 and protrudes radially inward is provided on the inner surface of the powder storage container 3. Is valid. That is, by providing the lift-up wings 34, the powder is forcibly lifted with the rotation of the powder storage container 3, and then dropped by its own weight. By repeating this operation during processing, the powder is efficiently stirred.

7. Plasma powder processing method The plasma powder processing method of the present embodiment uses low-pressure high-frequency plasma processing which is low-temperature plasma processing, and therefore, it has a high electron density at a temperature of 200 ° C. or less, further 100 ° C. or less. Do the processing. For this reason, surface modification of powder of various materials can be performed, and it is suitable also for surface modification processing of nanoparticles. In addition, since various active gases (reactive gases) described above are applicable as the gas for plasma generation without being limited to He gas, surface modification which imparts various functions such as etching, activation, reduction, adsorption, etc. Quality treatment can be performed.

  Further, according to the plasma powder processing method of the present embodiment, after completion of the plasma processing, the powder is recovered by keeping the chamber and the powder storage container in contact with the air by the non-air contact means. For this reason, the function of the powder subjected to the low pressure high frequency plasma processing is not deteriorated.

8. Advantages of the Plasma Powder Processing Apparatus and Method of the Present Embodiment By using the plasma powder processing apparatus described in the above embodiment, it is possible to stir the powder during plasma processing, so a large amount of powder is used. Even if there is any, it is possible to perform plasma processing efficiently, and to provide mass-produced powder which has been surface-modified and processed precisely and with high quality.

  In addition, since the plasma-treated powder can be recovered without being exposed to the atmosphere, it is possible to prevent the powder from being exposed to the atmosphere and deteriorating when taking out the powder after the treatment.

  Furthermore, plasma plasma is generated by generating reduced-pressure high-frequency plasma with an electrode discharge system suitable for modification purposes from among a counter electrode discharge system, a RIE electrode discharge system and a PE electrode discharge system in one plasma powder processing apparatus. Since processing can be performed, the installation space and installation cost of the plasma powder processing apparatus can be reduced.

9. Applications and Functions of Plasma-Treated Powder In the present embodiment, it is possible to plasma-treat powder of various materials such as metal, carbon, resin, ceramic and the like using the above-described plasma powder processing method. . Then, various functions such as etching, activation, reduction, and adsorption can be imparted to the powder with high quality. Moreover, since it is excellent in mass productivity and processing cost is low, it can be provided at a low price.

  In addition, since the plasma-treated powder can be taken out without being exposed to the air, it is possible to provide the plasma-treated powder with higher quality.

  Hereinafter, the present invention will be more specifically described based on examples.

1. First Experiment In the first experiment, a test was conducted as follows based on the conditions shown in Table 1 using a plasma powder processing apparatus using different types of low-pressure high-frequency plasma.

(1) Test examples 1 to 5
(A) Test example 1
As shown in FIG. 2, 5 g of nanocarbon having a particle diameter of 30 to 200 nm is stored in a powder storage container of a plasma powder processing apparatus of the counter electrode discharge type as shown in FIG. By supplying O ₂ gas and applying high frequency power under the condition that the process start temperature (S. temp) is 25 ° C., the reduced pressure high frequency plasma treatment is performed on the nanocarbon in the powder container to obtain nanocarbon A hydrophilization treatment was performed. In this test example, the low pressure high frequency plasma treatment was performed without rotating the powder container.

The output of high frequency power (RF output), the flow rate of O ₂ gas, the atmosphere pressure in the chamber, and the processing time were set to the conditions shown in Table 1 below.

(B) Test example 2
Using a plasma powder processing apparatus having a powder storage container as shown in FIG. 2, nanocarbon is stored in the powder storage container, and the powder storage container is opposed to the nanocarbon while being rotated at a rotation speed of 5 rpm. The nanocarbon was subjected to a hydrophilization treatment by performing reduced-pressure high-frequency plasma treatment using an electrode discharge method. The other conditions were set to the same conditions as in Test Example 1.

(C) Test example 3
The nanocarbon was subjected to a hydrophilization treatment under the same conditions as in Test Example 2 except that the PE electrode discharge type plasma powder processing apparatus as shown in FIG. 6 was used.

(D) Test example 4
The nanocarbon was subjected to a hydrophilization treatment under the same conditions as in Test Example 2 except that the plasma powder processing apparatus of the RIE electrode discharge type as shown in FIG. 3 was used.

(E) Test example 5
For comparison, nanocarbons not subjected to the hydrophilization treatment as in Test Examples 1 to 4 described above were prepared as Test Example 5.

(2) Evaluation The nanocarbon obtained in Test Examples 1 to 4 and an untreated nanocarbon (Test Example 5) were introduced into purified water, and dispersion in water immediately after, 5 seconds, and 10 seconds after introduction. The speed was visually observed to evaluate the hydrophilicity of the nanocarbon of each test example.

(A) Evaluation results of Test Examples 1, 2 and 5 First, Test Example 1 in which reduced-pressure high-frequency plasma processing was performed without rotational stirring while using the same counter electrode method, and reduced-pressure high-frequency plasma processing were performed while rotational stirring. The evaluation results of the hydrophilicity in Test Example 2 and Test Example 5 in which the low-pressure high-frequency plasma treatment was not performed are shown in FIG. 12 and Table 2 below. In addition, FIG. 12 is a photograph figure which shows the hydrophilicity evaluation result of Experiment 1, 2 and 5 in the 1st experiment of an Example.

  From FIG. 12 and Table 2, in Test Example 5 in which the plasma treatment was not performed, it can be seen that all the nanocarbons float on the water surface even after 10 seconds and are not hydrophilic. On the other hand, in Test Example 1 in which the plasma treatment was performed without rotational stirring, some particles were precipitated, but some particles floated on the water surface even after 10 seconds after addition, and all particles were uniform It turns out that it is not hydrophilized. On the other hand, in Test Example 2 in which the plasma treatment was performed while rotating and stirring, all particles were wet and uniformly dispersed in water when 5 seconds passed from the introduction, and all particles were uniform. It can be seen that the hydrophilization treatment was carried out.

  From this result, when performing hydrophilization treatment of powder such as nanocarbon using reduced pressure high frequency plasma, powder using a plasma powder processing apparatus provided with a powder storage container as shown in FIG. It has been confirmed that all the powders can be uniformly plasma-treated by performing the plasma treatment while rotating the body container.

(B) Evaluation results of Test Examples 2 to 4 Next, in order to investigate an electrode discharge system most suitable for hydrophilizing treatment of nanocarbon, Test Example 2 using a counter electrode discharge system and a PE electrode discharge system were used. The results of the hydrophilization treatment of Test Example 3 and Test Example 4 using the RIE electrode discharge system were compared. The evaluation results of hydrophilicity of Test Examples 2 to 4 are shown in FIG. 13 and Table 3. In addition, FIG. 13 is a photograph figure which shows the hydrophilicity evaluation result of Experiment Examples 2-4 in the 1st experiment of an Example.

  From FIG. 13 and Table 3, in any of Test Example 2 to Test Example 4, the hydrophilicity of most of the nanocarbon particles was improved. From this, when using a plasma powder processing apparatus that performs plasma processing while rotating and stirring as shown in FIG. 2, FIG. 3 and FIG. 6, the low pressure high frequency plasma processing is used regardless of which electrode discharge method is used. It has been confirmed that a certain effect can be obtained in powder processing.

  And, in Test Example 2 of Test Examples 2 to 4, all nanocarbons were uniformly dispersed in water 5 seconds after the introduction, and the hydrophilicity of the nanocarbon was most improved. From this result, it has been confirmed that it is most preferable to use the plasma powder processing apparatus of the counter electrode discharge type as shown in FIG. 2 in the hydrophilic treatment of the nanocarbon particles.

2. Second Experiment A. Hydrophilization treatment of PTFE film by difference of electrode discharge method (1) Test examples 6 to 9
In the second experiment, first, different electrode discharge methods were used in Test Examples 6 to 9, and polytetrafluoroethylene (PTFE) was subjected to low-pressure high-frequency plasma treatment to investigate an appropriate electrode discharge method for hydrophilization treatment of PTFE. The FIG. 14 is a view schematically showing four types of electrode discharge methods implemented in the second experiment.

(A) Test example 6
The sample film F of PTFE is attached to the inner peripheral surface of the powder container 3 of this apparatus using the plasma powder processing apparatus of the counter electrode discharge type shown in "opposite" of FIG. The surface of the sample film F was subjected to a hydrophilization treatment by performing a plasma treatment.

  In this experiment, the powder storage container 3 was not rotated, and the sample film F was attached to a portion where the powder was most likely to be retained when the powder was plasma-treated while stirring the powder.

Further, the conditions of the low pressure high frequency plasma processing were set as follows.
Plasma generation gas type: NH ₃
Supply flow rate: 150 sccm
RF output: 200 W
Atmospheric pressure: 50 Pa
Processing start temperature (S.Temp): 25 ° C

(B) Test example 7
Sample film F of PTFE under the same conditions as in Test Example 6 except that the external electrode 51 shown in “RIE 1” of FIG. 14 uses the plasma powder processing apparatus of the RIE 1 type covering the entire circumference of the outer peripheral surface of the chamber 2 The surface of the was subjected to a hydrophilization treatment.

(C) Test Example 8
The surface of the sample film F of PTFE was subjected to a hydrophilization treatment under the same conditions as in Test Example 6 except that the plasma powder processing apparatus of the PE electrode discharge type shown in “PE” of FIG. 14 was used.

(D) Test example 9
A sample film of PTFE under the same conditions as in Test Example 6 except that the external electrode 51 shown in “RIE 2” in FIG. 14 uses a plasma powder processing apparatus of the RIE 2 type covering only a part of the outer peripheral surface of the chamber 2 The surface of F was subjected to a hydrophilization treatment.

(2) Evaluation of Hydrophilization Treatment In each of Test Examples 6 to 9, water was dropped onto the surface of each PTFE sample film with a plasma treatment time of 0 seconds, 30 seconds, 60 seconds, and 90 seconds, to the surface of the sample film. The contact angle of water was measured and used as a measure of the evaluation of the hydrophilization treatment. The results are shown in Table 4 and FIG.

  From Table 4 and FIG. 15, in any of the electrode discharge methods of Test Example 6 to Test Example 9, the contact angle decreases as the treatment time as a whole becomes longer, and by using the reduced pressure high frequency plasma treatment, PTFE is obtained. It has been confirmed that the hydrophilicity of the powder can be appropriately improved. In addition, FIG. 15 is a graph which shows the experimental result of the hydrophilization experiment using 4 types of electrode discharge systems shown in FIG.

  Further, among Test Examples 6 to 9, Test Example 9 using the plasma powder processing apparatus of the RIE 2 method has the smallest contact angle and is preferable as a method of subjecting a PTFE film to a hydrophilization treatment. From this, in the case of PTFE, it is preferable that the high-frequency plasma treatment be performed in the sheath region where the anisotropy and the activity are intensified such that the external electrode covers only a part of the outer peripheral surface of the chamber. It could be confirmed.

B. Hydrophilization Treatment of PTFE Powder (1) Test Example 10 and Test Example 11
(A) Test Example 10
Next, 5 g of PTFE powder of nano-level with a particle diameter of 100 nm is stored in the powder storage container of the plasma powder processing apparatus of the RIE 2 system in which the highest hydrophilization effect is obtained in the above test. The PTFE powder was subjected to a hydrophilization treatment by performing reduced pressure high frequency plasma treatment while rotating the container.

In addition, the processing conditions of pressure reduction high frequency plasma were set as follows.
Plasma generation gas type: NH ₃
Supply flow rate: 150 sccm
RF output: 200 W
Atmospheric pressure: 50 Pa
Processing start temperature (S.Temp): 25 ° C
PTFE particles (throughput): 5 g
Stirring rotational speed: 5 rpm
Processing time: 600s

(B) Test example 11
For comparison, a PTFE powder not subjected to the hydrophilization treatment as in the above-described Test Example 10 was prepared as Test Example 11.

(2) Evaluation of Hydrophilization Treatment The PTFE powder obtained in Test Example 10 and the untreated PTFE powder (Test Example 11) were added to water, and the dispersion speed in water 60 seconds after the addition was It observed visually and evaluated the hydrophilicity of the PTFE nanoparticle of each test example.

  As a result of the evaluation, in the untreated PTFE powder of Test Example 11, the powder did not get wet with water and floated on the water surface even after 60 seconds from the introduction. On the other hand, in the case of Test Example 10 in which the reduced-pressure high-frequency plasma treatment was performed by the RIE 2 method, all the PTFE powder quickly settled in water and was uniformly dispersed. From this, it was confirmed that the PTFE powder can be appropriately subjected to the hydrophilization treatment by performing the low pressure high frequency plasma treatment by the RIE 2 method.

3. Discussion of the First Experiment and the Second Experiment From the results of the first experiment and the second experiment described above, when performing surface treatment of powder, it is preferable according to the type of powder to be treated. It was confirmed that the electrode discharge method was different. From this, as in the above-described embodiment, by configuring a plasma powder processing apparatus capable of switching between three types of electrode discharge methods, one apparatus is optimum for various applications. It has been confirmed that surface modification treatment of powder can be performed under various conditions.

  As mentioned above, although the present invention was explained based on an embodiment, the present invention is not limited to the above-mentioned embodiment. Various modifications can be made to the above embodiment within the same and equivalent scope of the present invention.

DESCRIPTION OF SYMBOLS 1 plasma powder processing apparatus 2 chamber 3 powder storage container 4 exhaust apparatus 5 high frequency power supply 6 rotation drive means 7 gas supply means 8 box 21 cylindrical body 22a, 22b sealing part 31 central body part 34 lift up wing 51 external electrode 51a first external electrode 51b second external electrode 52 internal electrode F sample film P powder

Claims (14)

A horizontally oriented cylindrical chamber,
A cylindrical powder container which can be taken in and out from one side of the chamber and can contain powder therein;
Pressure reducing means for holding the inside of the chamber and the powder container at a pressure lower than atmospheric pressure;
A gas supply means for supplying a gas for plasma generation into the chamber and the powder container;
An electrode for generating reduced-pressure high-frequency plasma by the gas for plasma generation in the chamber and the powder container;
A rotary drive unit configured to rotate the powder storage container with the central axis of the powder storage container as a rotation axis in a state where the powder storage container is placed in the chamber;
The powder stored in the powder storage container is subjected to plasma processing while rotating the powder storage container in a state where the powder storage container is placed in the chamber ,
As the electrodes, first and second external electrodes are provided facing each other on the outer peripheral surface of the chamber, and rod-shaped internal electrodes are provided in the powder storage container,
A switching means for switching the electrode to any one of a counter electrode discharge type electrode, a reactive ion etching electrode discharge type electrode and a plasma etching electrode discharge type electrode;
The switching means is
When the electrode of the counter electrode discharge system is used, any one of the first and second external electrodes is an electrode to which high frequency power is applied, and the other is an electrode to ground.
When the electrode of the reactive ion etching electrode discharge system is used, both or one of the first and second external electrodes is an electrode for applying high frequency power, and the internal electrode is an electrode for grounding.
When it is set as the electrode of the said plasma etching electrode discharge system, it is an electrode which grounds the said, 1st and 2nd external electrode, It is a switching means which makes the said internal electrode an electrode which applies high frequency electric power. apparatus.   The plasma powder processing apparatus according to claim 1, further comprising an air non-contact means for preventing the chamber and the powder storage container from being in contact with the air. The electrode is a counter electrode discharge type electrode,
First and second external electrodes are provided opposite to each other on the outer peripheral surface of the chamber,
The plasma powder processing according to claim 1 or 2, wherein any one of the first and second external electrodes is an electrode to which a high frequency power is applied, and the other is an electrode to be grounded. apparatus. The electrode is a reactive ion etching electrode discharge type electrode,
An external electrode is provided on the outer peripheral surface of the chamber as an electrode to which high frequency power is applied.
The plasma powder processing apparatus according to claim 1 or 2, wherein a rod-shaped internal electrode is provided in the powder container as an electrode to be grounded.   The plasma powder processing apparatus according to claim 4, wherein the external electrode covers the entire periphery of the outer peripheral surface of the chamber.   The plasma powder processing apparatus according to claim 4, wherein the external electrode covers a part of an outer peripheral surface of the chamber. The electrode is a plasma etching electrode discharge type electrode,
An external electrode is provided on the outer peripheral surface of the chamber as an electrode to be grounded.
3. The plasma powder processing apparatus according to claim 1, wherein a rod-shaped internal electrode is provided in the powder container as an electrode to which high frequency power is applied. The plasma powder processing apparatus according to any one of claims 4 to 7 , wherein the gas supply means doubles as the internal electrode. A gas supply control means is provided for resuming the supply of the gas for plasma generation after temporarily stopping the supply of the gas for plasma generation by the gas supply means for a predetermined time. The plasma powder processing apparatus of any one of 1 to 8 . 10. The plasma powder processing apparatus according to claim 9 , wherein the gas supply control means repeatedly performs supply and stop of the gas for plasma generation in a pulse shape. Plasma powder processing apparatus according to any one of claims 1 to 1 0 rotation axis of the powder container is characterized in that it is horizontal. The powder container is characterized in that it includes lift-up feathers that lift the powder to a predetermined height in the rotational direction of the powder container and then drop it as the powder container rotates. The plasma powder processing apparatus of any one of Claim 1 thru | or 11. A claims 1 to plasma powder processing method the powder under reduced pressure high-frequency plasma treatment using a plasma powder processing apparatus according to any one of claims 1 2,
A plasma powder processing method comprising plasma processing the powder stored in the powder storage container while rotating the powder storage container in a state where the powder storage container is placed in the chamber. After completion of the plasma treatment, a plasma powder processing method according to claim 1 to 3, the chamber and the powder container by the air non-contact means, and recovering the powder so as not to contact with the atmosphere .