JP2002220215A - Method for manufacturing nano carbon and nano carbon manufactured by the method, device for manufacturing nano carbon, method of patterning nano carbon and nano carbon base material patterned by use of the method and electron emission source using the patterned nano carbon base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for manufacturing an electron emission source by instantaneously transforming a surface of an arc discharged material consisting mainly of graphite into nano carbon by an arc discharge which does not necessarily require process vessels and the like but a welding arc torch or a similarly structured device and a method and a device for manufacturing a patterned electron emission source by transforming a part or parts of the surface of the arc discharged material into nano carbon. SOLUTION: A torch electrode 10 of an arc torch 1 which is the first electrode and an arc discharged material 2 using a graphite plate which is the second electrode are placed in the air facing each other. An arc discharge is generated by impressing electric potential between the torch electrode 10 and the arc discharged material 2. The graphite of the predetermined part of the material 2 is transformed into nano carbon by an arc discharge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing nanocarbon and nanocarbon produced using the method.
The present invention relates to a nanocarbon manufacturing apparatus, a nanocarbon patterning method, a nanocarbon substrate patterned using the method, and an electron emission source using the patterned nanocarbon substrate.

[0002]

2. Description of the Related Art A field electron emission source is energy saving and has a long life as compared with a thermoelectron emission source which requires heating. At present, materials for field electron emission sources include semiconductors such as silicon,
In addition to metals such as Mo and W, there are nanotubes. Among them, nanotubes are promising as a field electron emission source because they themselves have the size and sharpness sufficient to concentrate the electric field, are chemically stable, and have excellent mechanical strength. .

[0003] Conventional methods for producing nanotubes include laser ablation, arc discharge between graphite electrodes in an inert gas, and CVD using a hydrocarbon gas (Chemi).
cal Vapor Deposition). Among them, nanotubes manufactured by the arc discharge method,
It has few defects in the atomic arrangement and is suitable for a field electron emission source.

[0004] The process of the conventional arc discharge method is as follows. After disposing the two graphite electrodes in the container facing each other, the container is once evacuated, and then an inert gas is introduced.
Generates an arc. The arc anode evaporates violently, producing soot and depositing on the cathode surface. The arc is maintained for several minutes or more, and then the apparatus is opened to the atmosphere to remove the cathode deposit or collect the cathode deposit.

[0005] Cathode deposits are composed of a soft core containing nanotubes and a hard shell containing no nanotubes. When graphite containing a catalytic metal is used for the anode, nanotubes are present in the soot. A nanotube is taken out from a soft core or soot, and the nanotube is carried on a substrate to serve as an electron emission source.

[0006]

The problems in the production of nanocarbon such as nanotubes and the production of an electron emission source composed of the nanocarbon in the conventional arc discharge method are as follows.

A vacuum vessel, a vacuum exhaust device, and an inert gas introducing device are required, and the cost of the device is relatively high. Exhaust and release to the atmosphere must be repeated, and the process is long. After the process is completed, it is not suitable for continuous mass production because the cathode deposit or soot must be collected and the device must be cleaned. Further, in order to fabricate an electron-emitting device using nanocarbon generated by this method, more steps such as separation of a soft core and a hard shell, isolation and purification of soot from a soot, and loading on a substrate are required. There is also the problem that it is necessary.

The present invention does not necessarily require a process vessel or the like, and instantaneously changes the surface of a material to be arced mainly composed of graphite by arc discharge using a welding torch or a device having a similar structure. An object of the present invention is to provide a method for forming an electron emission source by transforming the material into carbon (including a nanotube), and to provide an apparatus for manufacturing the same.
Still another object of the present invention is to provide a method of manufacturing a patterned electron emission source by partially or partially deforming the surface of an arc-receiving material into nanocarbon, and to provide a manufacturing apparatus therefor.

[0009]

According to a first aspect of the present invention, there is provided a method for producing nanocarbon, comprising: arranging a first electrode and a second electrode mainly composed of a carbon material to face each other in the atmosphere; A step of applying a voltage between the first electrode and the second electrode to generate an arc discharge; and a step of changing a carbon material in a predetermined region of the second electrode to nanocarbon by the arc discharge. Features.

According to a second aspect of the present invention, in the method for manufacturing nanocarbon, the first electrode is a torch electrode provided on an arc torch, and the first electrode is moved relatively to the second electrode. A step of changing the carbon material in a predetermined region of the two electrodes into nanocarbon by the arc discharge.

According to a third aspect of the present invention, in the method for producing a nanocarbon according to the first or second aspect, the second electrode is provided on a surface of a base material. The carbon material in a predetermined region of the second electrode is changed to nanocarbon by the arc discharge while the base material is cooled by the cooling member while being held by the cooling member.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a nanocarbon according to the first or second aspect, wherein at least an arc generated between the first electrode, the second electrode, and both electrodes. The method is characterized in that a carbon material in a predetermined region of the second electrode is changed to nanocarbon by the arc discharge while covering a discharge region with a covering member.

According to a fifth aspect of the present invention, in the method for producing a nanocarbon according to the first or second aspect, the carbon material of the second electrode is graphite, activated carbon,
It is characterized by being one of amorphous carbon.

According to a sixth aspect of the present invention, in the method for producing a nanocarbon according to the first or second aspect, the second electrode is formed of a carbon material containing a catalyst metal and a catalyst metal. Carbon material formed on the surface, B
And B is a carbon material containing a catalyst metal, B is a carbon material formed on the surface, or B is a carbon material formed on the surface.

According to a seventh aspect of the present invention, in the method for producing a nanocarbon according to the sixth aspect, the catalyst metal is Li, B, Mg, Al, Si,
P, S, K, Ca, Ti, V, Cr, Mn, Fe, C
o, Ni, Cu, Zn, Ga, Ge, As, Y, Zr,
Nb, Mo, Rh, Pd, In, Sn, Sb, La, H
f, Ta, W, Os, Pt, or an oxide thereof;
It is characterized by being a nitride, carbide, sulfide, chloride, sulfate compound, nitrate compound, or a mixture thereof.

According to a eighth aspect of the present invention, in the method for producing a nanocarbon according to the first or second or fourth aspect, the arc discharge is performed while supplying a specific gas to a region where the arc discharge is generated. It is characterized by performing.

According to a ninth aspect of the present invention, in the method for producing a nanocarbon according to the eighth aspect, the specific gas is a rare gas such as Ar or He, air, or the like.
It is characterized by being a nitrogen gas, a carbon dioxide gas, an oxygen gas, a hydrogen gas or a mixed gas thereof.

According to a tenth aspect of the present invention, in the nanocarbon manufacturing method of the first or second aspect, the first electrode is mainly composed of graphite or W (tungsten). Features.

[0021] In the method for producing nanocarbon according to claim 11, in the method for producing nanocarbon according to claim 1 or 2, the arc discharge is operated by a direct current or a direct current pulse, and the second electrode is discharged by the arc discharge. The anode is characterized in that:

According to a twelfth aspect of the present invention, there is provided a method of producing a nanocarbon according to the first or second aspect, wherein the arc discharge is operated by an alternating current or an alternating current pulse.

[0021] The nanocarbon according to claim 13 is:
It is characterized by being manufactured using the method according to any one of claims 1 to 12.

According to a fourteenth aspect of the present invention, there is provided an apparatus for producing nanocarbon, comprising a first electrode, a carbon material containing a carbon material or a catalyst metal, or a carbon material having a catalyst metal formed on the surface. A voltage is applied between the first electrode and the second electrode, and an arc discharge is generated in a predetermined area of the second electrode by applying a voltage between the first electrode and the second electrode that is held at a predetermined interval in the atmosphere. An arc generating means comprising a power supply for converting the carbon material in the predetermined area into nanocarbon by the arc discharge, and a specific gas supply means for supplying a specific gas to the arc discharge generating area are provided. And

According to a fifteenth aspect of the present invention, in the nanocarbon producing apparatus according to the fourteenth aspect, the first electrode is a torch electrode provided on an arc torch. A moving unit configured to relatively move the second electrode; applying a voltage between the torch electrode and the second electrode while relatively moving the torch electrode and the second electrode; Is characterized in that an arc discharge is generated in a predetermined region, and the carbon material in the predetermined region is changed to nanocarbon by the arc discharge.

[0024] In the apparatus for producing nanocarbon according to claim 16, the second electrode is provided on a surface of a base material, and the first electrode is provided. And a holding unit for holding the second electrode at a predetermined interval has a cooling unit for cooling the base material.

According to a seventeenth aspect of the present invention, in the nanocarbon manufacturing apparatus according to the fourteenth or fifteenth aspect, at least the first electrode and the second electrode are connected to each other.
It is characterized in that it has an enclosing means for covering an electrode and an arc discharge region generated between the electrodes.

The method for patterning nanocarbon according to claim 18 is a step of arranging a first electrode and a second electrode mainly containing a carbon material in the air, A step of applying a voltage between the first electrode and the second electrode to generate an arc discharge; and while relatively moving the first electrode and the second electrode, the carbon material in a predetermined region of the second electrode is subjected to the arc discharge. It is characterized by having a process of changing to nanocarbon.

The method for patterning nanocarbon according to claim 19 is characterized in that the first electrode and the carbon containing an arbitrary patterned carbon material or an arbitrary patterned catalyst metal are formed. A step of disposing a second electrode mainly composed of a material or a carbon material whose surface is formed of a catalyst metal formed in an arbitrary pattern, in the air,
A step of applying a voltage between the first electrode and the second electrode to generate an arc discharge; and a step of changing a carbon material in a predetermined region of the second electrode to nanocarbon by the arc discharge. It is characterized by.

A method of patterning nanocarbon according to claim 20, wherein a first electrode and a second electrode mainly composed of a carbon material are opposed to each other in the atmosphere, and a surface of the second electrode is provided. Disposing a mask having an arbitrary opening pattern, applying a voltage between the first electrode and the second electrode to generate an arc discharge, and A step of changing the carbon material in a predetermined region of the second electrode into nanocarbon by the arc discharge.

According to a twenty-first aspect of the present invention, in the method for patterning a nanocarbon according to any one of the eighteenth to twentieth aspects, the first electrode is provided on an arc torch. It is a torch electrode.

A nanocarbon substrate according to a twenty-second aspect is characterized by being patterned using the method according to any one of the eighteenth to twenty-first aspects.

An electron emission source according to a twenty-third aspect uses the patterned nanocarbon substrate according to the twenty-second aspect.

[0032]

Embodiments of the present invention will be described below in detail with reference to the drawings. It should be noted that the present invention is not limited to the illustrated configuration, and various design changes can be made.

In the present invention, carbon nanotubes, carbon nanofibers, carbon nanoparticles, nanohorns, CN nanotubes, CN (nano) fibers, CN
Nanoparticles, BCN nanotubes, BCN (nano) fibers, BCN nanoparticles, or mixtures thereof are collectively referred to as nanocarbon.

FIG. 1 is a schematic diagram of a manufacturing (patterning) apparatus used in a nanocarbon patterning method, a nanocarbon manufacturing method, a nanocarbon and nanocarbon base material and an electron emission source manufacturing method according to an embodiment of the present invention. Model. The present embodiment uses a general-purpose welding arc torch such as TIG (inert gas arc welding) and a power supply (welding power supply) in the atmosphere, at atmospheric pressure, or in a predetermined gas atmosphere, and performs arc discharge on the material to be arced. Is generated for a short time. T
Instead of IG arc torch, MIG (metal-e
(electrode-inert-gas) torch or the like may be used. Further, a device having a structure similar to a TIG arc torch may be used.

TIG welding is a welding method in which an arc discharge is generated between a non-consumable W (tungsten) electrode and a base material in an inert gas envelope, and if necessary, a filler metal is added separately. It is.

As shown in FIG. 1, the apparatus of the present invention comprises a first
A welding arc torch 1 having a torch electrode 10 as an electrode, and a second arc torch 1
A voltage is applied between the arc material 2 as an electrode, a water-cooled bench 3 holding the arc material 2, and the arc torch 1 and the arc material 2 (for example, contact ignition, high voltage application, A high-frequency application, etc.), a welding power source 5 for generating an arc 4, a gas cylinder 6 serving as a gas supply source for supplying a predetermined gas to the arc torch 1, and a flow rate of a predetermined gas from the gas cylinder 6. And a flow meter 7 for adjusting the pressure. Reference numeral 8 denotes a tip of the arc torch 1.

FIG. 2 shows the tip 8 of the arc torch 1 in the nanocarbon production (patterning) apparatus shown in FIG.
It is an expanded sectional view of. As shown in FIG. 2, the tip 8 of the arc torch 1 includes a nozzle 9 of the arc torch 1, a torch electrode 10 as a first electrode made of tungsten or the like, an electrode holder 11 for holding the torch electrode 10, A space between the nozzle 9 and the electrode holder 11, which is constituted by a flow path of an encapsulating gas 12 supplied to the arc 4 generated between the arc torch 1 and the material to be arced 2.

The power supply 5 for general-purpose TIG welding is configured to flow gas 12 to the arc torch 1, and usually supplies argon (Ar) gas. In the production of nanocarbon, the type of gas used is not particularly limited, and rare gases such as argon (Ar) and helium (He), air, nitrogen (N ₂ ) gas, and carbon dioxide such as carbon dioxide (CO ₂ ) gas,
Oxygen (O ₂ ) gas, hydrogen (H ₂ ) gas, or a mixed gas thereof may flow. Also, it is not necessary to flow anything. However, it is more preferable to flow the gas 12 to the arc torch 1. In particular, when a rare gas is used, since the nanocarbon and the rare gas do not cause a chemical reaction, there is little possibility that the generated nanocarbon is destroyed. . That is,
In the atmosphere, nanocarbon and oxygen in the atmosphere may cause a chemical reaction, that is, the generated nanocarbon is likely to be gasified or deteriorated. Prevention is very effective.

Accordingly, a container is basically not necessary, but when it is desired to perform the operation in an inert gas to maintain the cleanliness and atmosphere of the work place, or to prevent the influence of convection caused by wind or the like. The whole device including the working unit may be put in a simple container (a vacuum container or a pressurized container, or a closed container or an open container) which is a wrapping means. The pressure in the container (envelope) is not particularly limited, but is preferably around atmospheric pressure from the viewpoint of operability.

In ordinary TIG welding, a W electrode containing thorium or a W electrode containing cerium is used as the torch electrode 10. In the production of nanocarbon, those electrodes may be used, but pure graphite should be used for the torch electrode 10 in order to prevent the molten fine particles of W from adhering to the material to be arced 2 as droplets. . The diameter of the torch electrode 10 is not particularly limited, but is preferably about 1 to 7 mm in order to use a general-purpose torch.

Further, like a general-purpose TIG welding torch,
It is desirable that the metal electrode holder 11 be water-cooled. When the arc 4 is generated continuously (or intermittently for a long time) for the synthesis or continuous mass production of large-area nanocarbon, the torch electrode 10 and the electrode holder 11, which are the first electrodes, are excessively heated. I will. As a result, the torch electrode 10 is greatly consumed, and the electrode holder 11 itself may be damaged. Gas to arc torch 1
If the electrode holder 11 is cooled by flowing (specific gas) or the like, the electrode holder 11 itself will not be damaged by heating, and furthermore, the torch electrode 10 is also cooled by the electrode holder 11, thereby suppressing electrode consumption. Is done.

The material to be arced 2 containing graphite to be subjected to nanocarbonization as a main component (that is, containing a large amount of carbon material) is a counter electrode of the torch electrode 10. As the carbon material, graphite, activated carbon, amorphous carbon and the like can be used. The size of the material to be arced 2 is not limited, but a thickness of 0.1 to 5 mm is appropriate. Further, the material to be arced 2 is protected from the heat of the arc 4 (that is, the arc 4 is protected).
In order to cool the material to be arced 2, it is better to process the material on a water-cooled bench 3, which is a water-cooled electrode base, in order to reduce the possibility of the material to be damaged 2 being broken by the heat of the material.

The material to be arced 2 may be dried well, but may contain moisture. However, if the material to be arced 2 contains moisture, the energy of the arc 4 is absorbed by the evaporation of the moisture, making it difficult to raise the temperature of the evaporation point. Conversely, if the material to be arced 2 is wet, wet, contains moisture, or is in water, the arc 4 can prevent the material to be arced 2 from being heated. Similarly, in order to prevent the material to be arced 2 from being heated, the material to be arced 2 is directly cooled with water,
It can be oil cooled. In addition, a cooling medium such as water or carbon dioxide can be sprayed or sprayed on the material to be arced 2.

It is sufficient that the discharge period of the arc 4 is about 3 seconds or less. In particular, in the case of the same predetermined area, there is no problem. Even if the discharge is continued, nanocarbon can be produced, but the material to be arced evaporates and loses its flatness, making it unsuitable for an electron emission source. Further, the arc current can be used in a wide range of 5A to 500A.
A to 300A are suitable. When the arc 4 is operated with a pulse current, the frequency is not limited, but 1 Hz to 500 Hz is appropriate in view of the actual situation of a general-purpose power supply. The distance between the arc torch 1 and the material to be arced 2 is 0.1 to 10 mm
Is appropriate. Further, when the arc torch 1 and the material to be arced 2 are relatively and continuously moved, that is, when the arc 4 is continuously generated so as to trace different portions of the material to be arced 2, the arc 4 The discharge period is not limited. The discharge of the arc 4 may be continuously performed and continuously moved, or the discharge may be performed intermittently and intermittently, and the discharge region maintaining an optimal distance for the production of nanocarbon may be formed in a discontinuous line shape. .

When the arc 4 is operated with a direct current or a direct current pulse, the conditions for producing nanocarbon on the surface of pure graphite are extremely narrow. However, if graphite containing a material containing a catalytic metal or the like is used as the material to be arced 2, a large amount of nanocarbon can be produced on the surface thereof. The catalyst metal or the like includes L
i, B, Mg, Al, Si, P, S, K, Ca, Ti,
V, Cr, Mn, Fe, Co, Ni, Cu, Zn, G
a, Ge, As, Y, Zr, Nb, Mo, Rh, Pd,
In, Sn, Sb, La, Hf, Ta, W, Os, P
t or a mixture thereof can be used.

For inclusion in graphite, these metals themselves or oxides, nitrides, carbides, sulfides, chlorides, sulfate compounds, nitrate compounds and the like can be used. Instead of containing the catalyst metal or the like in the graphite, the catalyst metal or the like, or an oxide, a nitride, a carbide, a sulfide, a chloride, a sulfate compound, or a nitrate compound is sprayed, coated, and plated on the surface of the graphite. , Coating (deposition) or implantation.
That is, the material to be arced only needs to have a structure in which the graphite and the catalyst metal are heated by the arc 4 at the same time.

When the arc 4 is operated by an alternating current or an alternating current pulse, a large amount of nanocarbon can be produced on the surface even if pure graphite is used. Also, a large amount of nanocarbon can be produced by using the above-mentioned catalyst-containing graphite electrode or a graphite electrode whose surface is covered with a catalyst. Rather, pure graphite has a higher density of nanocarbons per unit plane.

FIGS. 3 and 4 show an example of a method of transforming only one or a plurality of desired surfaces into nanocarbon at one time. An arc 4 is formed between the material to be arced 2 and the torch electrode 10 via a mask 13 (hard mask) having a surface pattern to be transformed into nanocarbon.
Is discharged.

FIG. 3 shows a state in which the arc 4 is discharged between the material to be arced 2 and the torch electrode 10. FIG. 4 shows FIG.
2 shows nanocarbon grown by the method of (1). FIG.
In the figure, reference numeral 14 denotes a growth portion of the nanocarbon. 3 and FIG. 4, the same components as those in FIG. 1 and FIG.

In the material to be arced 2, nanocarbon is formed only on the surface where the arc 4 contacts. Mask 13
May be used as long as it can withstand the high temperature and thermal shock of the arc, such as high melting point metal, ceramics and graphite. The mask 13 may be placed directly on the material to be arced 2 or may be slightly floated via a spacer.

In the case of an AC arc or an AC pulse arc, a material containing pure graphite, a metal catalyst or the like is contained as the material 2 to be arced, or a material containing a metal catalyst or the like is sprayed, coated, plated, or coated (deposited). ) Or injected graphite can be used. On the other hand, in the case of a DC arc or a DC pulse arc, pure graphite cannot be used, but graphite containing a material containing a metal catalyst or the like, or a material containing a metal catalyst or the like is sprayed, coated, plated, coated (deposited) or Injected graphite can be used.

FIGS. 5 to 7 show another example of a method of transforming only one or a plurality of desired surfaces into nanocarbon at once. In this method, a material containing a metal catalyst 15 or the like is sprayed, applied, plated, coated (deposited), or injected into a portion of the graphite surface to be transformed into nanocarbon, or an arc-receiving material is used.

FIG. 5 shows a state in which the arc 4 is discharged between the material to be arced 2 and the torch electrode 10. FIG. 6 shows FIG.
2 shows nanocarbon grown by the method of (1). FIG.
In the figure, reference numeral 14 denotes a growth portion of the nanocarbon. FIG.
FIG. 7 is an enlarged view of a portion indicated by a dotted line in FIG. 6. In FIGS. 5 to 7, the same components as those in FIGS. 1 and 2 are described.
The same numbers are assigned and the description is omitted.

As shown in FIG. 7, the catalytic metal 15 substantially disappears from the surface of the material to be arced 2 by the processing using the arc discharge 4. More specifically, actually, the surface of the material to be arced 2 is slightly dented, and nanocarbon is formed in the depressed portion.

When a DC arc or a DC pulse arc is used, nanocarbon is formed on the surface covered with the metal catalyst 15 or the like, but is hardly formed on the surface not covered with the metal catalyst 15 or the like. . In the case of this method, it is not preferable to use an AC arc or an AC pulse arc. This is because nanocarbon is also formed in a portion not covered with the metal catalyst 15 or the like. Note that, unlike the method shown in FIG. 3, this method does not use the mask 13 at the time of arc discharge machining, so that the method is simpler.

According to the manufacturing method of the present invention, continuous production is possible by sequentially replacing the material to be arced 2. Alternatively, continuous production is also possible by arranging the materials to be arced 2 and moving the arc torch 1.

That is, the material to be arced 2 may be moved while the arc torch 1 is fixed, or the arc torch 1 may be moved while the material to be arced 2 is fixed. Furthermore,
It is also possible to move both the arc torch 1 and the material to be arced 2.

The relative movement between the arc torch 1 and the material to be arced 2 may be performed manually (by a human hand), or the arc torch 1 may be moved in three directions (ie, in a plane parallel to the material to be arced 2). (The X direction and the Y direction) and a device having a moving means for moving in a direction perpendicular to the plane (Z direction) may be performed automatically. In particular, if an NC device (numerical control device) or the like is used, it is possible to expose only the region desired to be transformed into nanocarbon to the arc 4, or to expose only the pattern portion of the catalyst metal 15 to the arc 4.

In the above manufacturing method, the arc torch 1
When air or nitrogen is used as the gas to be flowed into the N, nanocarbon containing N, so-called CN nanotube can be formed. Further, as the electrode to be arced, graphite containing a material containing B, graphite containing a metal catalyst, or a material containing B, or a material containing B, or a material and a catalyst containing B, which are sprayed, coated, plated, coated (deposited), or injected. When graphite containing a metal-containing material is sprayed, applied, plated, coated (deposited), or injected, a nanocarbon containing a BCN network, that is, a so-called BCN nanotube can be formed. Similarly, various nanocarbons can be formed by changing the atmosphere gas and additives. Where B is boron, C
Represents carbon and N represents nitrogen.

In the electron emission source containing nanocarbon produced by the above method, the performance of the electron emission source is improved by oxidizing and removing the nanoparticles that inhibit the electron emission.

As a method of using the nanocarbon produced by the production method of the present invention as an electron emission source, a conventional diode or triode method can be used. In particular, it is suitable for a display tube, a display panel, a light emitting element, a light emitting tube, a light emitting panel, and the like. Further, by emitting electrons from the nanocarbon generated at a specific location, application to a display device having a complicated pattern is also possible.

An example of specific experimental results is shown below. FIG.
Is a graphite plate containing Ni / Y (Ni and Y content:
General-purpose welding arc torch 1 (torch electrode 10: graphite) with a surface of 4.2 and 1.0 mole%, plate thickness: 2 mm)
2 is a photograph obtained by processing in open air (under atmospheric pressure) and observing the surface with a scanning electron microscope. The arc current is the result when the direct current is 100 A. In the figure,
It can be seen that a large amount of nanocarbon, especially multi-walled carbon nanotubes, covers the surface. Here, almost the same results were obtained when graphite containing activated carbon, amorphous carbon, or a catalyst metal was used instead of the graphite plate. In addition, when a specific gas, particularly a rare gas, was used, the yield of the generated nanocarbon was increased. From this, it was confirmed that the use of a rare gas was very effective.

FIG. 9 shows an example in which the surface of pure graphite was processed with an AC arc of 100 A, and the surface was observed with an electron microscope. It can also be seen from the figure that a large amount of nanocarbon, particularly multi-walled carbon nanotubes, is formed on the surface. This deposit also contained carbon nanoparticles and the like. Using the same sample, electrons were emitted from a fluorescent tube having a diode structure, and the phosphor screen was illuminated. It was visually observed that the phosphor screen emitted light. Here, the result when using activated carbon, amorphous carbon, graphite containing a catalyst metal, or the like, and the effect when using a specific gas were the same as those in FIG. 8 instead of the graphite plate.

In the above embodiment, an example was shown in which a graphite plate was used as the material to be arced 2 having graphite (second electrode) formed on the surface (that is, the base material also serves as the second electrode). It is also possible to use a metal plate provided with a solid pattern or a patterned graphite layer on a metal plate (that is, a substrate and a second electrode are formed separately).

It is also possible to use an insulating plate such as a glass substrate or a ceramic substrate provided with a solid pattern or a patterned graphite layer. When this insulating plate is used, a solid pattern or a patterned metal (a metal such as aluminum that does not evaporate during arc discharge) may be provided between the insulating plate and the graphite layer. If an insulating plate is used, it is easier to manufacture than a graphite plate or the like, and the cost is lower.

Further, the metal layer can be formed as a thick film by, for example, a screen printing method, or can be formed as a thin film by a CVD method, a mask evaporation method, or the like. This metal layer can be used as a wiring layer for applying a potential to the nanocarbon to emit electrons when nanocarbon is used as an electron emission source.

Further, the catalyst metal 15 may be a solid pattern or a patterned metal.
As for the graphite layer and the metal layer, a solid pattern may be used, but a layer patterned according to the pattern of the catalyst metal 15 may be used. This catalytic metal 15
For example, a thin film can be formed by a CVD method, a mask evaporation method, or the like.

In the above embodiment, the base material (the material to be arced 2)
Although an example in which the above nanocarbon is used as it is has been described, it is of course possible to separate and purify the nanocarbon from the base material (the material to be arced 2) and use it as a single nanocarbon. In the above embodiment, the angle between the material to be arced 2 and the torch electrode 10 is:
Although an example of a right angle is shown, the angle is not limited to a right angle, and may be any angle that does not hinder the production of nanocarbon.

The nanocarbon produced by the production method of the present invention can be used for an occlusion material such as hydrogen. The nanocarbon produced by the production method of the present invention can be used for a mixture for a secondary battery electrode, a mixture for a secondary battery electrode, a fuel cell electrode, and a secondary battery electrode. The nanocarbon produced by the production method of the present invention can be used as a mixture with rubber, plastic, resin, ceramics, steel, concrete and the like. By mixing the nanocarbon with these materials, the strength, thermal conductivity, electric conductivity, etc. can be improved.

The nanocarbon produced by the production method of the present invention is characterized in that soot contains a large amount of nanotubes, particularly multi-walled carbon nanotubes.
In addition, the soot includes a nanohorn in addition to the multi-walled nanotube. Similarly, there is a feature that carbon nanoparticles and the like are also included.

Here, the nanohorn refers to a carbon nanoparticle having a shape obtained by rounding a graphite sheet in a conical shape and having a tip closed in a conical shape (see “Pore structure”).
ofsingle-wall carbon nanohorn aggregates / K.Murat
a, K.Kaneko, F.Kokai, K.Takahashi, M.Yudasaka, SI
ijima / Chem. Phys. Lett., vol. 331, pp.14-20 (200
0) ").

[0072]

According to the present invention, it is possible to provide a very easy method and apparatus for producing nanocarbon.
In addition, the method of manufacturing (patterning) and manufacturing (patterning) of nanocarbon which is easy to manufacture and capable of continuous mass production and an electron emission source (substrate for electron emission source) using the same
An apparatus can be provided. Furthermore, it is possible to provide a method and an apparatus for easily producing a nanocarbon group in an arbitrary pattern at an arbitrary one or a plurality of locations.

[Brief description of the drawings]

FIG. 1 is a view schematically showing an apparatus for producing (patterning) nanocarbon.

FIG. 2 is a partially enlarged sectional view of the nanocarbon manufacturing (patterning) apparatus of FIG.

FIG. 3 is a diagram showing an example of a method for forming (patterning) nanocarbon at a specific location.

FIG. 4 is a view showing nanocarbon grown by the method of FIG. 3;

FIG. 5 is a diagram showing another example of a method for forming (patterning) nanocarbon at a specific location.

FIG. 6 is a diagram showing nanocarbon grown by the method of FIG. 5;

FIG. 7 is an enlarged view of a portion indicated by a dotted line in FIG. 6;

FIG. 8 is a view showing nanocarbon processed and formed on a graphite surface containing Ni / Y metal by DC arc operation.

FIG. 9 is a diagram showing nanocarbon formed on the surface of pure graphite by AC arc operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Arc torch, 2 ... Arc-receiving material, 3 ... Water-cooled bench, 4 ... Arc, 5 ... Power supply, 6 ... Gas cylinder, 7 ... Gas regulator and flowmeter, 8 ... Tip of arc torch, 9 ... Arc torch Nozzle, 10: Torch electrode, 11: Electrode holder, 12: Encapsulated gas, 13: Mask, 14: Growth site of nanocarbon, 15: Catalyst metal

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Shigeo Ito 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd. F-term (reference) 4G046 CA00 CB01 CC09 CC10 5C031 DD17 DD19 (54) [Title of Invention] Nanocarbon , Nanocarbon manufactured by using the method, nanocarbon manufacturing apparatus, nanocarbon patterning method, nanocarbon substrate patterned by using the method, and nanocarbon patterned by the method Electron emission source using substrate

Claims (23)

[Claims] 1. A first electrode and a second electrode mainly composed of a carbon material.
Disposing electrodes facing each other in the air; applying a voltage between the first electrode and the second electrode to generate an arc discharge; and disposing a carbon material in a predetermined region of the second electrode. A method for producing nanocarbon, comprising a step of converting into nanocarbon by arc discharge. 2. The method according to claim 1, wherein the first electrode is a torch electrode provided on an arc torch, and the carbon material in a predetermined region of the second electrode is discharged by the arc discharge while relatively moving the torch electrode and the second electrode. 2. The method for producing nanocarbon according to claim 1, further comprising a step of converting the carbon into nanocarbon. 3. The second electrode is provided on a surface of a base material, and the base material is held by a cooling member, and the base material is cooled by the cooling member while a predetermined area of the second electrode is provided. The method for producing nanocarbon according to claim 1, wherein the carbon material is converted into nanocarbon by the arc discharge. 4. An arc discharge region generated between the first electrode, the second electrode, and both electrodes is covered with an enclosing member, and a carbon material in a predetermined region of the second electrode is nano-sized by the arc discharge. The method for producing nanocarbon according to claim 1, wherein the method is changed to carbon. 5. The method according to claim 1, wherein the carbon material of the second electrode is any one of graphite, activated carbon, and amorphous carbon. 6. A carbon material containing a catalyst metal, a carbon material having a catalyst metal formed on its surface,
2. A carbon material containing B and a catalyst metal, a carbon material having B formed on a surface thereof, or a carbon material having B and a catalyst metal formed on a surface thereof. Or the method for producing nanocarbon according to 2. 7. The method according to claim 7, wherein the catalyst metal is Li, B, Mg, Al,
Si, P, S, K, Ca, Ti, V, Cr, Mn, F
e, Co, Ni, Cu, Zn, Ga, Ge, As, Y,
Zr, Nb, Mo, Rh, Pd, In, Sn, Sb, L
a, Hf, Ta, W, Os, Pt or their oxides, nitrides, carbides, sulfides, chlorides, sulfate compounds,
The method for producing nanocarbon according to claim 6, wherein the method is a nitric acid compound or a mixture thereof. 8. The method for producing nanocarbon according to claim 1, wherein the arc discharge is performed while supplying a specific gas to a region where the arc discharge is generated. 9. The nanocarbon according to claim 8, wherein said specific gas is a rare gas such as Ar or He, air, nitrogen gas, carbon dioxide gas, oxygen gas, hydrogen gas or a mixed gas thereof. Manufacturing method. 10. The method for producing nanocarbon according to claim 1, wherein the first electrode contains graphite or W (tungsten) as a main component. 11. The method according to claim 1, wherein the arc discharge is operated by direct current or direct current pulse, and the second electrode is used as an anode of the arc discharge. 12. The method for producing nanocarbon according to claim 1, wherein the arc discharge is operated by alternating current or alternating current pulse. 13. A nanocarbon produced by using the method according to claim 1. Description: 14. A first electrode and a second electrode mainly composed of a carbon material containing a carbon material or a catalyst metal or a carbon material having a catalyst metal formed on a surface thereof are arranged at predetermined intervals in the atmosphere. Applying a voltage between the held electrode and the first electrode and the second electrode,
Arc generating means comprising a power source for generating an arc discharge in a predetermined area of the second electrode, and converting the carbon material in the predetermined area into nanocarbon by the arc discharge; An apparatus for producing nanocarbon, comprising a specific gas supply means for supplying. 15. The method according to claim 15, wherein the first electrode is a torch electrode provided on an arc torch, and further comprises a moving means for relatively moving the torch electrode and the second electrode. While moving, a voltage is applied between the torch electrode and the second electrode to generate an arc discharge in a predetermined area of the second electrode, and the arc discharge causes the carbon material in the predetermined area to be nanocarbon. The apparatus for producing nanocarbon according to claim 14, wherein the apparatus is changed to: 16. The apparatus according to claim 16, wherein the second electrode is provided on a surface of the base material, and holding means for holding the first electrode and the second electrode at a predetermined interval includes cooling means for cooling the base material. The nanocarbon production apparatus according to claim 14, wherein the apparatus has: 17. An apparatus for producing nanocarbon according to claim 14, further comprising an enclosing means for covering at least an arc discharge region generated between said first electrode, said second electrode and both electrodes. . 18. A step of arranging a first electrode and a second electrode mainly composed of a carbon material to face each other in the air, and applying an electric voltage between the first electrode and the second electrode to form an arc. Generating a discharge, and changing a carbon material in a predetermined region of the second electrode into nanocarbon by the arc discharge while relatively moving the first electrode and the second electrode. Nanocarbon patterning method. 19. A method according to claim 19, wherein the first electrode comprises a carbon material formed in an arbitrary pattern or a carbon material containing a catalyst metal formed in an arbitrary pattern or a catalyst metal formed in an arbitrary pattern. A step of arranging a second electrode mainly composed of a carbon material formed on the surface thereof in the air, and applying a voltage between the first electrode and the second electrode to generate an arc discharge And a step of changing a carbon material in a predetermined region of the second electrode into nanocarbon by the arc discharge. 20. A step of arranging a first electrode and a second electrode mainly composed of a carbon material in air, and a step of arranging a mask having an arbitrary opening pattern on a surface of the second electrode. Applying a voltage between the first electrode and the second electrode to generate an arc discharge; and discharging the carbon material in a predetermined region of the second electrode corresponding to an opening of the mask by the arc discharge. A method for patterning nanocarbon, comprising the step of: 21. The method for patterning nanocarbon according to claim 18, wherein the first electrode is a torch electrode provided on an arc torch. 22. A nanocarbon substrate patterned using the method according to any one of claims 18 to 21. 23. An electron emission source using the patterned nanocarbon substrate according to claim 22.