JP2009046713A - Device for stirring particle and vapor deposition apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of particles which are not stirred when a powdery granular substance is stirred. <P>SOLUTION: A device 3 for stirring the particles comprises: a vacuum tank 2; a vessel 73 which is placed in an vapor deposition apparatus 1 having a vapor deposition source 5 and accommodates the powdery granular substance 7 therein; a scraper 75 for stirring the particles of the powdery granular substance 7; and a drive mechanism 72 for relatively driving the scraper 75 with respect to the vessel 73. At least the inner wall of the vessel 73 is coated with the same type of a material as the powdery granular substance 7, and at least a part contacting with the inner wall of the vessel 73 of the scraper 75 is coated with the same type of a material as a vapor deposition material 11 evaporated in the vapor deposition source 5 or the same type of a material as the powdery granular substance 7. Chips produced by the abrasion between the coating on the vessel 73 and the coating of the scraper 75 do not become an impurity, because they are the same type of the material as the powdery granular substance 7 or the vapor deposition material 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is used for a fuel cell, an exhaust gas catalyst metal carrier, an air cleaning catalyst carrier, a gas sensor, a magnetic material, and a dielectric material.

  Carbon is used for the electrode part of the fuel cell, and platinum having catalytic action for ionizing hydrogen is supported on the carbon. When carrying platinum or the like, a wet method is used. Specifically, carbon powder is put in a platinum oxide solution, and platinum is deposited in the carbon defective portion in the platinum powder to carry platinum particles of several nm to several tens of nm. While this wet method is simple, there are problems such as agglomeration, uniformity, and reaction deterioration when assembled and operated in a fuel cell.

  Therefore, loading of the catalytic metal by the dry method has started. In other words, this is a method in which a support material, that is, platinum itself is vapor-deposited on carbon powder by sputtering or a vapor deposition arc method, and platinum fine particles are supported on the carbon powder (see, for example, Patent Document 1).

  In addition, there is a fuel cell catalyst obtained by supporting a particulate alloy powder on the surface of carbon particles and then heat-treating it (see, for example, Patent Document 2).

JP 2006-140017 A JP 2006-222092 A

  However, in order to support the catalyst metal on the individual particles of the granular material by the dry method, it is necessary to sufficiently stir the granular material during vapor deposition, and the container for storing the granular material, the granular material When contacted with a scraper that stirs, the surface of the container or the scraper is scraped to generate debris. Depending on the material of the container or scraper, this scrap becomes an impurity. Therefore, conventionally, a slight gap has been formed between the container and the scraper. However, when the particles have a size of nanometer unit of 1 μm or less, there has been a problem that particles that cannot be stirred by any means enter the gap between the container and the scraper.

The above problem is arranged in a vacuum chamber and a fine particle forming apparatus having a vapor deposition source,
A device for stirring particles of powder, comprising a container for storing powder, a scraper for stirring the powder, and a drive mechanism for driving the scraper with respect to the container,
Coating at least the inner wall of the container with the same material as the powder,
The problem is solved by a particle agitating device in which at least a portion of the scraper that is in contact with the inner wall of the container is coated with the same material as the vapor deposition material evaporated by the vapor deposition source or the same material as the powder.

  Specifically, at least the inner wall of the container is coated with the same material as the granular material that is the object to be supported or the main element constituting the granular material (hereinafter referred to as “the same type of material as the granular material”), On the other hand, the same material as the vapor deposition material evaporated by the vapor deposition source at the part in contact with the inner wall of the scraper container, or the same element as the main material constituting the vapor deposition material (hereinafter referred to as “the same type of material as the vapor deposition material”) or powder The material is coated and disposed so that the scraper is rubbed with the inner surface of the container containing the powder and granular material, so that no gap is opened between the inner surface of the container and the scraper. This ensures that the particles of the granular material collide with the scraper. The particles that collide with the scraper are pushed up above the scraper. By repeating this, the particles of the granular material are changed upside down and uniformly stirred.

Further, the above-mentioned problem is a vapor deposition apparatus having a vacuum chamber, a coaxial arc vapor deposition source, and a stirring device,
The stirring device comprises a container for storing powder, a scraper for stirring particles of the powder, and a drive mechanism for driving the scraper relative to the container.
At least the inner wall of the container is coated with the same material as the granular material, and at least a portion of the scraper that is in contact with the inner wall of the container is the same material as the evaporation material evaporated by the evaporation source or the powder. This is solved by a vapor deposition apparatus coated with the same kind of material as the granular material.

  Specifically, in a vapor deposition apparatus in which a vapor deposition apparatus and a stirring apparatus are arranged in a vacuum chamber, at least the inner wall of the container is coated with the same kind of material as the granular material that is the object to be supported, while the scraper container Coating the same kind of material as the vapor deposition material evaporated by the vapor deposition source on the part contacting the inner wall or the same kind of material as the above-mentioned granular material, and arranging to scrape the inner surface of the container containing the granular material and the scraper, A mechanism is provided for pressing so as not to open a gap between the inner surface of the container and the scraper. The scraper is driven relative to the container by the drive mechanism of the stirring device in a state where the gap is pressed so as not to open between the inner surface of the container and the scraper. This ensures that the particles of the granular material collide with the scraper. The particles that collide with the scraper are pushed up above the scraper. By repeating this, the particles of the granular material are changed upside down and uniformly stirred. When the particles appear above the scraper, that is, on the surface of the granular material, they are exposed to vapor of the vapor deposition material evaporated by the vapor deposition apparatus. Thereby, a deposition material is deposited on the surface of the particles. Since the particles are mixed upside down and stirred uniformly, all the particles in the container are uniformly deposited after a certain time.

  The waste generated by scraping the coating of the container and the scraper generated at this time is not a problem because it is the same kind of material as the powder or vapor deposition material.

Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.
First, a conventional dry method will be described for comparison.
FIG. 4 is a schematic diagram of a fine particle forming apparatus 101 using a coaxial vacuum arc vapor deposition source 105 for supporting a catalyst.

  The vacuum chamber 102 has a cylindrical shape. A stirrer 103 having a container 173 for containing the raw material 107 and a fixed blade 175 which is a scraper for stirring the raw material 107 is housed in the vacuum chamber 102.

  The coaxial vacuum arc deposition source 105 includes a cylindrical deposition material 111 made of platinum attached to a cathode electrode, a hat-shaped insulator 114 made of alumina (hereinafter referred to as a hat-type insulator), a trigger electrode 113, Have The vapor deposition material 111 attached to the cathode electrode, the hat-type insulator 114, and the trigger electrode 113 are attached in close contact with each other concentrically.

  The anode electrode 123 is made of stainless steel and has a cylindrical shape. The anode electrode 123 is attached concentrically with the vapor deposition material 111 attached to the cathode electrode. The coaxial vacuum arc deposition source 105 is attached to the wall surface of the vacuum chamber 102 via a support column (not shown) and a vacuum flange (not shown).

In addition, the power supply device 106 is shown in the drawing with a simple wiring diagram. The power supply device 106 includes a trigger power supply 131, an arc power supply 132, and a capacitor unit 133.
The trigger power supply 131 is composed of a pulse transformer, and transforms a pulse voltage in units of μS with an input of 200 V to about 17 times, and outputs a trigger pulse with a positive polarity of 3.4 kV and in units of several μS.
The arc power supply 132 is a DC power supply with a capacity of 100 V and several A, and charges the capacitor unit 133. Since the charging time requires about 1 second, the discharge cycle is 1 Hz.
The capacitor unit 133 has four capacitors each having a capacitance of 2200 μfarad and a withstand voltage of 100 V connected in parallel.
The positive output terminal of the trigger power supply 131 is connected to the trigger electrode 113, the negative terminal is connected to the same potential as the negative output terminal of the arc power supply 132, and is further connected to the cathode electrode. Both terminals of the capacitor unit 133 are connected between the positive and negative terminals of the arc power supply 132.

The vacuum exhaust system 109 includes a turbo molecular pump 151, a partition valve 152, a rotary pump 153, and an adjustment valve 154. The turbo molecular pump 151 to the rotary pump 153 are connected by metal pipes, and the vacuum chamber 102 is evacuated. By performing evacuation, the inside of the vacuum chamber 102 is kept at 10 ⁻⁵ Pa or less.

The stirring device 103 is housed in the vacuum chamber 102. A rotation mechanism 172 is connected to the center of the lower surface of the stirring vessel 173.
FIG. 5 is a perspective view of a part of the conventional stirring device 103. The granular material 107 is accommodated in the stirring container 173. A rotating mechanism 172 that rotates the stirring container 173 is arranged below the fixed table 171 although not shown in the drawing.
The material of the stirring vessel 173 is stainless steel, and the inner walls (inner side surface and bottom surface) are buffed.
FIG. 6 shows an enlarged sectional view of a part of a conventional stirring vessel.
The fixed blade 175 is made of stainless steel. Reference numeral 107a denotes carbon particles.

The operation of the coaxial vacuum arc deposition source 105 will be described with reference to FIG.
The electric charge is charged at 100 V by the arc power source 132. Here, the capacitor unit 133 is 8800 μF. By applying a trigger pulse of 3.4 kV from the trigger power source 131 to the trigger electrode 113 and applying it between the vapor deposition material 111 attached to the cathode electrode and the trigger electrode 113 via the hat-type insulator 114, a hat type Creeping discharge occurs on the surface of the insulator 114, the electric charge stored in the capacitor unit 133 is discharged between the vapor deposition material 111 and the anode electrode 123, a large amount of current flows into the cathode electrode, and it is attached to the cathode electrode made of platinum. The deposited vapor deposition material 111 forms a plasma of platinum from the liquid phase to the gas phase.

  At this time, since a large amount of current (2000 A to 5000 A) flows through the cathode electrode between 200 μS and 500 μS, a magnetic field is formed in the vapor deposition material 111 attached to the cathode electrode. Electrons in the plasma fly under the coaxial vacuum arc deposition source 105 under the Lorentz force generated by the magnetic field formed by the deposition material 111 attached to the cathode electrode.

  Platinum ions, which are vapor deposition materials in the plasma, are polarized and are attracted to electrons flying in front of the coaxial vacuum arc deposition source 105 by Coulomb force and fly forward of the coaxial vacuum arc deposition source 105. It becomes like this.

  On the other hand, platinum ions, which are the deposition material in the plasma, are polarized and fly forward of the coaxial vacuum arc deposition source 105 by Coulomb force. As a result, platinum ions grow using the carbon powder 107a as a nucleus, and platinum particles in nanometer units are formed.

  More specifically, platinum ions are irradiated toward the carbon powder 107 in the stirring vessel 173. Here, the stirring container 173 is rotated by the rotating mechanism 172, and the carbon particles 107 a in the container 173 are stirred by the fixed blade 175 of the stirring device 103. When the carbon particles 107 a collide with the fixed blade 175, they appear on the fixed blade 175 and are exposed to platinum ions. By continuing this one after another, platinum fine particles are uniformly formed on all the carbon particles in the stirring vessel 173.

Next, referring to the schematic diagram of FIG. 6, how the unstirred particles that are a problem are generated will be described.
If a gap g is provided between the inner wall of the stirring vessel 173 and the fixed blade 175 in order to make a rotational movement, some carbon particles enter the gap g below the fixed blade 175 and are not stirred. In order to prevent this, when the inner wall of the stirring vessel 173 and the lower end of the fixed blade 175 are brought into contact with each other, the inner wall of the stirring vessel 173 or the fixed blade 173 is scraped to generate shavings. Since the material of the stirring vessel 173 and the fixed blade 175 that are the source of shavings is stainless steel, it becomes an impurity.

  Therefore, in the present invention, a means for eliminating the gap between the stirring vessel and the fixed blade is provided, and on the other hand, measures against generated shavings are taken.

Hereinafter, the present invention will be described in detail with reference to the drawings.
1 to 3 show schematic views of the present invention.
The fine particle forming apparatus 1 to which the stirring device 3 of the present invention is applied will be described with reference to the drawings. In addition, description is abbreviate | omitted about the same part as a comparative example.

  FIG. 1 shows a schematic diagram of a dry deposition source. A fine particle forming apparatus 1 using a coaxial vacuum arc vapor deposition source for supporting a catalyst will be described with reference to FIG.

  The vacuum chamber 2 has a cylindrical shape. A stirrer 3 having a container 75 for containing the powder 7 as a raw material and a fixed blade 75 for stirring the powder 7 is housed in the vacuum chamber 2.

  The configuration, function, and performance of the coaxial vacuum arc deposition source 5, the power supply device 6, the gas supply system 8, and the vacuum exhaust system 9 in the figure are the same as those in the comparative example, and thus the description thereof is omitted.

The stirring device 3 is accommodated in the vacuum chamber 2.
The material of the stirring vessel 73 is stainless steel, and the inner wall is coated with DLC (diamond-like carbon) with a thickness of 1 μm as a coating layer 73a. The fixed blade 75 is made of stainless steel. The lower end portion of the fixed blade 75, that is, the portion in contact with the inner wall of the stirring vessel 73 is coated with platinum as a coating layer 75a with a thickness of 1 μm or DLC at 1 μm.
The coating method may be any of CVD, sputtering, and arc.

  That is, in the present invention, as shown in FIG. 2, the inner wall of the stirring vessel 73 is coated with DLC, which is the same kind of material as the carbon 7, and the fixed blade 75 is irradiated with the vapor deposition material 11. By coating platinum, which is the same material as platinum, or DLC, which is the same kind of material as the granular material 7, and further pressing the fixed blade by a holding spring 76, a gap between the inner wall of the stirring vessel 73 and the fixed blade 75 is formed. lost.

  Thereby, in the state which pressed the fixed blade | wing 75 against the inner wall of the stirring container 73, the stirring container 73 is rotated and the granular material 7 is stirred. That is, as shown in FIG. 3, since the fixed blade 75 is in contact with the inner wall of the stirring vessel 73, the nanoparticle-sized particle 7 a also has no gap between the bottom surface of the stirring vessel 73 and the fixed blade, so that the fixed blade 75 is always used. And is pushed up on the fixed blade 75 and stirred.

  Further, the coating layer 75a is coated with a thickness of 1 μm on the lower end of the fixed blade 75, that is, the portion that contacts the inner wall of the container 73.

  A bracket 74 is attached to the fixed stage 71, and a rotation mechanism 72 is connected to the center of the lower surface of the container 73.

A holding spring 76 is attached between the bracket 74 and the fixed blade 75.
A load is applied to the fixed blade 75 by the holding spring 76 so that the lower end of the fixed blade 75 is brought into contact with the inner wall of the container 73.

Next, the state of stirring in the stirring vessel 73 will be described in detail.
FIG. 2 is an enlarged schematic view of a part of the stirring vessel 73. The fixed blade 75 is made of stainless steel. Reference numeral 7 a denotes carbon powder, which is stored in the stirring vessel 73. For ease of explanation, the coating layer 75a of the fixed blade 75 represents only the portion in contact with the bottom surface.
FIG. 3 is an explanatory view showing a state in which the carbon particles 7a are pushed up.
For ease of explanation, the coating layer 75a of the fixed blade 75 represents only the portion in contact with the bottom surface.

First, the structure of the solution means of a problem is demonstrated with the schematic diagram of FIG.
Since the carbon particles 7a are rotationally moved so that none of the carbon particles 7a enter under the fixed blades 75 and are stirred, no gap is provided between the inner wall of the stirring vessel 73 and the fixed blades 75. In the present invention, the inner wall of the stirring vessel 73 is coated with the same material as the powder 7, and the fixed blade 75 is coated with the same material as the vapor deposition material to be irradiated or the same material as the powder 7. The gap between the inner wall of the stirring vessel 73 and the fixed blade 75 was eliminated.

Next, the operation of the problem solving means will be described with reference to FIG.
Specifically, using the holding spring 74, the fixed blade 75 is pressed against the inner wall of the stirring vessel 73 to stir the granular material 7. As the fixed blade 75 comes into contact with the inner wall of the stirring vessel, the nano-sized particle 7a also does not have a gap between the inner wall of the stirring vessel 73 and the fixed blade 75, so it always collides with the fixed blade 75 and is indicated by an arrow in the figure. Thus, it is pushed onto the fixed blade 75 and stirred.

  On the other hand, the fixed blade 75 comes into contact with the inner wall of the stirring vessel 73 to cut the inner wall of the stirring vessel 73 or the lower end portion of the fixed blade 75. For example, when DLC is coated on the inner wall of the stirring vessel 73 and platinum is coated on the lower end portion of the fixed blade 75, DLC or platinum powder is generated. Since it is the same kind of material as the vapor deposition material 11, it does not become an impurity.

  As described above, according to the method or apparatus for stirring particles in a vacuum according to the present invention, even when the particle size becomes a size of nanometer unit of 1 μm or less, it can be stirred sufficiently uniformly. On the other hand, no impurities are generated.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

  In the embodiment, DLC is coated on the inner wall of the container, and platinum is coated on the fixed blade. However, the present invention is not limited to this. For example, when alumina powder is used as a granular material, alumina is vapor-deposited on the inner wall of the container. Further, alumina may be deposited on the fixed blade.

  In addition, when an alumina layer is formed on the surface of the granular material, the fixed blade may be coated with alumina or aluminum. When titania powder is used as the granular material, titania may be vapor-deposited on the inner wall of the container, and titania may also be vapor-deposited on the fixed blade.

  In the driving mechanism of the embodiment, the container is moved to fix the scraper blade, but the blade may be moved to fix the container. Moreover, you may move both.

  Further, the motion of the drive mechanism is not limited to a rotational motion that is a circle or an arc, but may be a translational motion that is linear or parallel.

It is sectional drawing explaining the fine particle formation apparatus of this invention. It is a fragmentary sectional view explaining the stirring apparatus of this invention. It is a figure which shows the coating layer of the inner wall of the stirring container 173, and the lower end of the fixed blade | wing 175. FIG. It is a fragmentary sectional view explaining the stirring apparatus of this invention. It is a figure explaining the function of a coating layer. The state in which the carbon particles 7a are pushed up is indicated by arrows. It is sectional drawing explaining the fine particle formation apparatus of a comparative example. It is a one part perspective view of the stirring apparatus of a comparative example. The relationship between a stirring container and a fixed blade is shown. It is a fragmentary sectional view explaining the stirring apparatus of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vapor deposition apparatus (fine particle formation apparatus), 2 ... Vacuum tank, 3 ... Stirring apparatus, 5 ... Coaxial type vacuum arc vapor deposition source, 6 ... Power supply device, 7 ... Powder granule Material (raw material, carbon powder), 7a ... particle, 8 ... gas supply system, 9 ... evacuation system, 11 ... deposition material, 13 ... trigger electrode, 14 ... insulation Insulator (hat-type insulator), 23 ... anode electrode, 31 ... trigger power source, 32 ... arc power source, 33 ... condenser unit, 51 ... turbo molecular pump, 52 ... partition valve, 53 ... Rotary pump, 54 ... Adjustment valve, 71 ... Fixed stage, 72 ... Rotating mechanism, 73 ... Container, 73a ... Coating layer, 74 ... Bracket, 75 ...・ Scraper (fixed blade), 75a ... coating layer, 76 · Pressing spring,
101 ... Vapor deposition device (fine particle forming device), 102 ... Vacuum tank, 103 ... Stirrer,
105 ... Coaxial vacuum arc deposition source, 106 ... Power supply device, 107 ... Granules (raw material, carbon powder), 107a ... Particles, 108 ... Gas supply system, 109 ...・ Vacuum exhaust system,
DESCRIPTION OF SYMBOLS 111 ... Evaporation material, 113 ... Trigger electrode, 114 ... Insulator (hat-type insulator), 123 ... Anode electrode, 131 ... Trigger power supply, 132 ... Arc power supply, 133 ... · Condenser unit, 151 ··· Turbo molecular pump, 152 ··· Partition valve, 153 ··· Rotary pump, 154 · · · Adjustment valve, 171 ··· Fixed stage, 172 · · · Rotary mechanism, 173 ···・ Stirring container, 174 ... bracket, 175 ... scraper (fixed blade),

Claims (8)

Arranged in a vacuum chamber and a vapor deposition apparatus having a vapor deposition source,
A particle agitation device comprising a container for storing powder, a scraper for stirring particles of the powder, and a drive mechanism for driving the scraper relative to the container,
An apparatus for stirring particles, wherein at least an inner wall of the container is coated with the same material as the powder. 2. The particles according to claim 1, wherein at least a portion of the scraper that is in contact with the inner wall of the container is coated with a material that is the same type as a vapor deposition material that is evaporated by the vapor deposition source or a material that is the same type as the granular material. Stirring device. 2. The particle agitation apparatus according to claim 1, wherein the material of the granular material is carbide or carbon. 2. The particle agitation apparatus according to claim 1, wherein a material of the powder is an oxide ceramic. The particle stirring apparatus according to claim 4, wherein the oxide ceramic is alumina or titania.   The particle agitation apparatus according to claim 1, wherein a material of the vapor deposition material is a metal or a metal oxide.   The particle agitation apparatus according to claim 6, wherein the metal is platinum or aluminum. A vapor deposition apparatus having a vacuum chamber, a coaxial arc vapor deposition source, and a stirring device,
The stirring device comprises a container for storing powder, a scraper for stirring particles of the powder, and a drive mechanism for driving the scraper relative to the container.
At least the inner wall of the container is coated with the same material as the granular material, and at least a portion of the scraper that is in contact with the inner wall of the container is the same material as the evaporation material evaporated by the evaporation source or the powder. Vapor deposition device, characterized by being coated with the same kind of material as the granular material.

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