WO1999011846A1

WO1999011846A1 - Coiled carbon fiber, and method and apparatus for manufacturing the same

Info

Publication number: WO1999011846A1
Application number: PCT/JP1998/003899
Authority: WO
Inventors: Seiji Motojima
Original assignee: Electron Property Research Institute Co., Ltd.
Priority date: 1997-09-01
Filing date: 1998-09-01
Publication date: 1999-03-11
Also published as: JP3215656B2; JPH1181051A; TW363938B

Abstract

A coiled carbon fiber of 0.01-5 νm in fiber diameter, 0.1-2000 νm in coil diameter, 0-50 νm in coil pitch and 100 νm-5 m in coil length, including a coiled carbon fiber having a clockwise-twined double spiral structure and a coiled carbon fiber having a counterclockwise-twined double spiral structure; and a method of manufacturing the same, comprising placing a metal catalyst, a gas of a compound of an element of the group 15 or 16 in the periodic table and a sealing gas in a reaction tank, and heating hydrocarbon or carbon monoxide to a temperature of 600-950 °C while applying an electrostatic field thereto to decompose the hydrocarbon or carbon monoxide and obtain a carbon fiber grown to the mentioned shape.

Description

Description Coiled carbon fiber, method for producing the same, and apparatus for producing the same

The present invention relates to a coiled carbon fiber used as a material for a three-dimensional reinforced composite material, an electromagnetic wave absorbing material, a micromechanical element, a micro-port switching element, a microsensor, a microfilter, an adsorbent, a method of manufacturing the same, and a method of manufacturing the same It relates to manufacturing equipment. Background art

In recent years, with the spread of mobile phones, personal computers, electromagnetic cookers, etc., the electromagnetic wave environment has increased in places close to the lives of citizens, causing malfunctions of medical equipment due to electromagnetic waves, and obstacles to operation of aircraft, railway cars, etc. Concerns about health problems have become a major social problem. For this reason, many electromagnetic wave absorbing materials and shielding materials are currently proposed and put into practical use. For example, carbon black, carbon fiber, and the like are dispersed in an electrical insulator such as synthetic resin or rubber to reduce the electrical resistivity, thereby providing electromagnetic wave shielding properties based on reflection loss and dielectric loss.

Carbon fibers are made from conventional organic fibers, and are obtained by subjecting them to infusibilization, carbonization, graphitization, etc., such as PAN-based carbon fibers and pitch-based fibers obtained from polyacrylonitrile fibers. In addition to the pitch-based carbon fiber obtained, there is a recently developed vapor-grown carbon fiber obtained by pyrolysis of hydrocarbons. Vapor-grown carbon fiber is formed in a straight line, has high strength, has a wide range of properties from metallic to semiconductive, and is expected to be applied as a functional material.

As a method for producing a vapor-grown carbon fiber, there is a method disclosed in Japanese Patent Publication No. 51-33210. In this method, a mixed gas of a hydrocarbon such as benzene and a carrier gas is first introduced into a reaction tube supporting a metal powder catalyst maintained at a temperature of 100 ° C. or more, at a temperature of 100 to 1 μm. The nucleus of fiber growth is formed at a flow rate of 50 O cmZ, and then the fiber is grown at a flow rate of 10 to 3 O cm / min. However, these carbon fibers can reflect electromagnetic waves, but have a problem that electromagnetic wave absorption based on dielectric loss is not always sufficient. The carbon fiber obtained by the method for producing a vapor-grown carbon fiber had a linear shape and the diameter of the fiber did not reach the micron order. In addition, when a transition metal is used as a catalyst, the yield of the coiled carbon fiber varies significantly depending on the metal manufacturer, storage conditions, pretreatment conditions, and the like, and the coiled carbon fiber may not be obtained at all. There was also. In addition, there was a problem that it was not possible to chemically synthesize a large amount of carbon fiber having a large diameter and a long diameter in a micron order.

Furthermore, there has been no production method or production apparatus capable of controlling the coil diameter, coil pitch, and coil length, and obtaining coiled carbon fibers with high reproducibility and yield.

The present invention has been made to solve the problems existing in the above prior art. An object of the present invention is to provide a coiled carbon fiber having a large coil diameter, a long coil length, and capable of efficiently absorbing and shielding electromagnetic waves.

Still another object is to provide a method and an apparatus for manufacturing a coiled carbon fiber which can effectively control a coil diameter, a coil pitch, and a coil length, and can improve reproducibility and yield. . Disclosure of the invention

In order to achieve the above object, the coiled carbon fiber of the present invention is formed into a coil shape by carbon fiber, the fiber diameter is 0.15 / zm, and the coil diameter is 0.1 to 0.1 / zm. 2 0 0 0 // m, the pitch of the coil is 0 to 50 μα and the length of the coil is 1 ◦ 0 μπι to 5 m, and the coil has a right-handed double spiral structure. And those having a left-handed double helix structure.

According to this configuration, the coiled carbon fiber has a large coil diameter, a long coil length, and can efficiently absorb and shield electromagnetic waves.

Further, the method for producing a coiled carbon fiber of the present invention includes the steps of: providing a metal catalyst, a gas of a compound belonging to Group 15 or 16 of the periodic table, a hydrogen gas, and a sealing gas; Heats carbon oxide to a temperature of 600 to 950 ° C and forms an electrostatic field And decompose hydrocarbons or carbon monoxide.

According to this configuration, the growth of the coiled carbon fiber can be promoted, particularly by applying an electrostatic field.

Further, in the method for producing a coiled carbon fiber, the metal catalyst is nickel, titanium or tungsten, the compound is a compound containing a sulfur atom or a phosphorus atom, the hydrocarbon is acetylene, and the seal is The gas is nitrogen or hemi-gas.

According to this configuration, since the metal catalyst, the gas compound of the Group 15 or Group 16 compound of the periodic table, and the hydrocarbon are each limited, it is possible to reliably obtain the desired coiled carbon fiber. it can.

In addition, in the method for producing a coiled carbon fiber, the electrostatic field is a non-variable electrostatic field or a variable electrostatic field.

According to this configuration, since the electrostatic field has a superimposed waveform, the growing carbon fiber can be formed in a coil shape, and the coil diameter, the coil pitch, and the coil length can be effectively controlled. .

Further, the apparatus for producing coiled carbon fiber of the present invention distributes a hydrocarbon gas or a carbon monoxide gas, a gas of a compound belonging to Group 15 or 16 of the periodic table, and a hydrogen gas to a reaction vessel having a heater. And an inlet for injecting the seal gas, and a base material for forming a high-voltage electrostatic field or a conductor at a predetermined distance from the base material in the reaction vessel. The coiled carbon fibers are grown on a substrate.

According to this configuration, the raw material gas and the seal gas can be introduced into the reaction vessel, the acetylene, thiophene and hydrogen gas introduced into the reaction vessel are collected on the substrate, and the coiled carbon fiber is efficiently formed on the substrate. Can grow well. Further, by forming a high-voltage electrostatic field on the base material, the carbon fibers growing from the base material can be formed into a coil shape, and the coil diameter, the coil pitch, and the coil length can be effectively controlled. .

In the above-described coiled carbon fiber manufacturing apparatus, the substrate is movably disposed, and the substrate is moved in accordance with the growth of the coiled carbon fiber. According to this configuration, the coiled carbon fibers grown on the base material can be easily collected, and a new base material can be arranged at the position where the growth is most likely to occur, so that the coiled carbon fibers can be continuously arranged. It can be manufactured in a special way. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view of a main part showing an apparatus for manufacturing a coiled carbon fiber according to a first embodiment.

Fig. 2 is an electrical circuit diagram showing the electrical configuration of the high-voltage electrostatic field generator.

FIG. 3 is a sectional view of a main part showing a manufacturing apparatus according to a second embodiment.

FIG. 4 is an essential part cross sectional view showing the operation of the manufacturing apparatus of the second embodiment.

FIG. 5 is a sectional view of a main part showing a manufacturing apparatus according to a third embodiment.

FIG. 6 is an essential part cross-sectional view showing another example of the manufacturing apparatus of the first embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment)

Hereinafter, the coiled carbon fiber according to the embodiment of the present invention will be described in detail.

The coiled carbon fiber is formed in a coil shape by carbon, the diameter of the fiber is 0.01 to 5 μιη, and the diameter of the coil is 0. ~ 200 μm πι, pitch of koinole is 0 ~ 50 μm and length of koinole is 100! 55 m, and the coils include those having a right-handed double helical structure and those having a left-handed double helical structure. The coiled carbon fiber has a coil diameter substantially in the order of a micron, can absorb and block electromagnetic waves, and has excellent elasticity and high strength.

When a coiled carbon fiber is irradiated with electromagnetic waves from the outside and is exposed to a fluctuating electric field or magnetic field, an induced current due to induced electromotive force flows in the coil according to Faraday's law, generating joule heat and absorbing the electromagnetic waves . In addition, the electromagnetic waves undergo circular and circular deflections by the coiled carbon fiber, and furthermore, the coiled carbon fiber is highly conductive, and suffers from reflection and scattering losses, etc., so that it rapidly declines. Moreover, since the coiled carbon fibers are oriented in all directions in three dimensions, it is considered that electromagnetic waves are efficiently absorbed no matter where they are applied.

The frequency range of the electromagnetic wave absorbed by the coiled carbon fiber is as follows: Depends on pitch and coil length. If the coil length is long and the coil diameter is large, electromagnetic waves in the low frequency range will be absorbed. On the other hand, if the coil diameter is small, electromagnetic waves in the high frequency region are absorbed. Therefore, by controlling these, it can be applied as an electromagnetic wave absorber in a wide range. It can also be used as a new electrode material, energy conversion element, microsensor, micromechanical element, microfilter, high temperature 'high pressure' corrosion and elastic packing, antibacterial material, adsorbent, etc.

Further, the coiled carbon fiber is used as a catalyst carrier as a biomaterial. For example, cells can be embedded in coils of coiled carbon fiber to exert a catalytic action in vivo.

Coiled carbon fibers can absorb electromagnetic waves in a wider wavelength range as the coil diameter is larger, and can absorb more electromagnetic waves as the coil length is longer. The right-handed double-helical coil and the left-handed double-helical coil exist in a ratio of approximately 1: 1. Therefore, even though it looks like a single helical structure in terms of macro, it has a double helical structure in microscopic terms.

Next, an apparatus for producing coiled carbon fiber will be described.

As shown in FIG. 1, a reaction vessel 12 is a horizontal thermo-chemical vapor synthesis apparatus formed in a tubular shape, and is capable of growing coiled carbon fibers 10 therein. The reaction vessel 12 is made of a metal material such as stainless steel or Inconel, or a ceramic material such as ceramic, alumina, or quartz. The material of the reaction vessel 12 is preferably transparent quartz in terms of catalytic activity and internal observation. The openings 13 at both ends of the reaction vessel 12 are closed by an insulating rubber stopper 14, and the inside of the reaction vessel 12 is kept electrically insulated.

The annular inlet 15 protrudes from the upper peripheral surface of the center of the reaction vessel 12, and is a gas containing hydrocarbon gas or carbon monoxide gas, or a group 15 or 16 element of the periodic table. And the hydrogen gas is allowed to flow into the reaction vessel 12.

As the hydrocarbon gas, a gas containing carbon atoms such as acetylene, methane, and propane or a carbon monoxide gas is used. In order to form carbon fiber into a coil, Acetylene is preferred in view of the anisotropy of the catalytic activity on the crystal plane.

Compounds containing sulfur atoms, such as sulfur, thiophene, methyl mercaptan, and hydrogen sulfide, or compounds containing phosphorus atoms, such as phosphorus and phosphorus trichloride, are used as elements of Groups 15 and 16 of the periodic table. Is used. Of these, thiophene is preferred. The concentration of the gas containing an element of Groups 15 and 16 of the periodic table in the reaction atmosphere is preferably 0.01 to 5 volumes. /. And more preferably within the range of 0.1 to 0.5% by volume. If the concentration is less than 0.01% by volume or exceeds 5% by volume, it becomes difficult to grow the coiled carbon fibers 10.

Further, a pair of annular injection ports 16 are formed so as to protrude from upper peripheral surfaces of both ends of the reaction vessel 12 so as to inject a seal gas into the reaction vessel 12. The seal gas used is an inert gas that is chemically inert, such as nitrogen gas or helium gas, and does not react with system substances. When the sealing gas is injected into the reaction vessel 12, it is possible to prevent extra or harmful effects of the oxygen gas or the like from being added to the reaction system in the reaction vessel 12.

Further, an annular outlet 17 is formed on the lower peripheral surface of the center of the reaction vessel 12 so as to correspond to the inlet 15, and hydrocarbon gas flowing through the reaction vessel 12 is provided. Carbon monoxide gas, seal gas, gas of compound of group 15 or 16 of the periodic table, hydrogen gas and gas generated by decomposition reaction are discharged.

The heater 18 is annularly mounted at the center of the reaction vessel 12 so as to sandwich the inflow port 15 and the outflow port 17 so as to raise the temperature of the reaction vessel 12 to a constant temperature. The temperature is preferably set within a range of 600 to 950 ° C, and more preferably within a range of 700 to 850 ° C. When the reaction temperature is lower than 600 ° C. or higher than 950 ° C., the yield of the coiled carbon fiber 10 sharply decreases.

As a base material on which the coiled carbon fibers 10 grow, a substrate 19 formed in an elongated rectangular plate shape is used. On the surface of the substrate 19, a catalyst 20 made of metal powder is applied. The substrate 19 is one of allotropic carbon materials and is formed of graphite, also called graphite. The connecting wires 21 are connected to both ends of the substrate 19 in pairs, and the connecting wires 21 are supported by the insulating rubber stoppers 14 so that the substrate 19 is in the air of the reaction vessel 12. Supported. And one connection line 2 1 is connected to a high-voltage electrostatic field generator 22 for applying an electrostatic field to the coiled carbon fiber 10 of the reaction vessel 12 內, and the other connection line 21 is open. You.

The metal catalyst 20 is at least one compound selected from transition metal oxides, carbides, sulfides, phosphides, carbonates and carbosulfides, and is preferably nickel, titanium or tungsten. It is a solid solution with oxygen, oxides, carbides, sulfides, phosphides, carbonates or carbosulfides. Of these, nickel is even more preferred. The form of the metal catalyst 20 may be any of a powder, a metal plate, a sintered plate of a powder and the like, and is preferably a fine powder or a sintered plate having an average particle size of about 5 μπι.

The coil diameter, coil pitch, and coil length of the coiled carbon fiber 10 depend on the crystal anisotropy and the particle size of the metal catalyst 20. Therefore, if the crystal plane anisotropy changes due to the voltage of the electrostatic field or hydrogen gas, the coil diameter, coil pitch, and coil length also change. For example, as the particle size of the metal catalyst 20 decreases, the coil diameter decreases. In the case of the fine metal catalyst 2 °, it may be sprayed or applied on the substrate 19. These metal catalysts 20 can be obtained by oxidizing, carbonizing, phosphating, carbonating and carbonizing under predetermined conditions before the reaction, in addition to a solid solution or a compound which has previously become a compound. Is also used.

The distance between the inflow port 15 for introducing the raw material gas and the like into the reaction vessel 12 and the substrate 19 is set to be within the range of 2 to 20 times. The smaller the distance between the inlet 15 and the substrate 19 is, the more the yield of the coiled carbon fibers 10 can be improved. However, if the distance between the inlet 15 and the substrate 19 is less than two legs or more than 2 Omm, no coiled carbon fiber 10 can be obtained, and only carbon powder or straight carbon fiber Will begin to be analyzed.

The rod-shaped electrode 23 is formed of a conductive metal, and is disposed above the substrate 19 in the reaction vessel 12 at a predetermined distance. The diameter of the rod-shaped electrode 23 is about 2 mm. Also, one end of the rod-shaped electrode 23 is connected to the ground wire 24, and the other end is open. Then, a predetermined electrostatic field can be generated between the substrate 19 and the rod-shaped electrode 23.

The high-voltage electrostatic field generator 22 is disposed at a location away from the reaction vessel 12, It is connected to the board 19 via the connection line 21. The electric circuit of the high-voltage electrostatic field generator 22 will be described. As shown in FIG. 2, a breaker 26, a power switch 27, and a voltage regulator 28 are connected in series to a 100 V AC power supply terminal 25. The indicator lamp 29 is connected in parallel with the voltage regulator 28. The voltage regulator 28 can adjust the voltage by a variable terminal 30. The primary coil 32 of the transformer 31 for high voltage and harmonic generation is connected in parallel to the voltage regulator 28. The voltmeter 33 is connected in parallel with the primary coil 32 of the transformer 31. One end of the secondary coil 34 of the high voltage and harmonic generation transformer 31 is left open, and the other end of the output terminal 35 is connected to the output terminal 35 via a protection resistor 36 of about 1 Ω. The connection line 21 is connected to the substrate 19 in the reaction vessel 12.

The protection resistor 36 functions to alleviate electric shock and to prevent electric leakage when an abnormal situation occurs on the short circuit path. As described above, one end on the output side of the secondary coil 34 of the high-voltage and harmonic generation transformer 31 is open. Therefore, no current flows on the output side of the secondary coil 34 of the transformer 31 for generating high voltage and harmonics, only high voltage is applied, and a high-voltage electrostatic field having a superimposed waveform including harmonic components is applied. You.

Then, after setting the variable terminal 30 to a predetermined resistance value in the voltage regulator 28, when the power switch 27 is turned on, the indicator lamp 29 is turned on, and the high voltage and harmonic generation transformer 31 is turned on. A high voltage is generated at the output side of the secondary coil 34. This high voltage applies a high-voltage electrostatic field into the reaction vessel 12 via the connection line 21 and the substrate 19.

The electrostatic field is a non-variable electrostatic field or a variable electrostatic field generated by the high voltage electrostatic field generator 22. The static electrostatic field is an electric field having a linear waveform generated by a constant voltage, and the variable electrostatic field is an electric field having an AC waveform such as a sine wave, a rectangular wave, a sawtooth wave, and a superimposed wave. Among these electrostatic fields, an electric field having a superposed waveform including a harmonic component is preferable. An electric field having a superimposed waveform can be obtained by an electric circuit having the transformer 31 for generating high voltage and harmonics, an electric circuit using a semiconductor, or the like. Among them, an electrostatic field having a superimposed waveform including a harmonic component is obtained by an electric circuit including a transformer 31 for generating high voltage and harmonics in the electric circuit. The superposition The waveform is obtained by superimposing sine waves of various wavelengths and the like in a superimposed manner. Various harmonic AC waveforms of appropriate wavelengths are added in a state of being shifted in phase, and these waveforms are added to obtain an AC waveform. A strain is formed on the top.

By forming such an electrostatic field, the thermal decomposition of the reaction gas can be promoted. In addition, positively charged reactive species, which are ionized by thermal decomposition and are positively charged, are efficiently guided to the metal catalyst 20 on the substrate 19, and the molecular motion of the reactive species is activated, thereby promoting the growth of carbon fibers. Is done. Then, by giving a direction to the grown carbon fiber by the superimposed waveform including the harmonic component, the coiled carbon fiber can be grown.

Therefore, the reaction rate can be improved, the coiled carbon fibers can be grown, and the yield can be improved. Also, by increasing the anisotropy of the crystal plane of the metal catalyst 20, coiled carbon fibers 10 having a small coil diameter can be obtained, and by reducing the anisotropy, coiled carbon fibers having a large coil diameter can be obtained. Fiber 10 is obtained. Therefore, the size of the coil diameter of the coiled carbon fiber 10 can be controlled.

Next, a method for producing the coiled carbon fiber will be described.

The substrate 19 to which the nickel powder 20 has been applied is supported at an appropriate position in the reaction vessel 12 by the connection wire 21. Then, the openings 13 at both ends of the reaction vessel 12 are closed by the insulating rubber stopper 14.

Next, acetylene, thiophene and hydrogen gas are introduced into the reaction vessel 12 from the inlet 15. Acetylene, thiophene, and hydrogen gas flow while contacting the substrate 19 in the reaction vessel 12 and flow out from the outlet 17. Further, nitrogen gas is injected from the pair of inlets 16 to prevent extra or harmful effects of oxygen gas or the like from being applied to the reaction system on the substrate 19.

Next, after the variable terminal 30 is connected to a predetermined position in the voltage regulator 28 of the high-voltage electrostatic field generator 22, the power switch 27 is turned on, and the high voltage is applied to the secondary coil 34 of the transformer 31. Generate. Thereby, an electrostatic field is applied between the substrate 19 and the rod-shaped electrode 23 via the connection line 21. Further, the reaction vessel 12 is heated to 600 to 950 ° C. by the heater 18. As a result, in a reaction site consisting of a ternary system of nickel 20, carbon, hydrogen, sulfur or phosphorus and oxygen, acetylene is thermally decomposed by nickel 20 by catalytic catalysis, and a single crystal of nickel carbide { nickel carbide (N i ₃ C) to that contain sulfur (S) and oxygen (O)} is formed. Further, the single crystal of nickel carbide is decomposed into nickel 20 and carbon, and intragranular and intergranular diffusion occurs on the crystal plane, and carbon fibers are formed on substrate 19.

At this time, due to the anisotropy of the nickel 20 crystal plane, the carbon fiber grown from the crystal plane having high catalytic activity has a large growth and curls so as to be outside the carbon fiber grown from the crystal plane having low catalytic activity. Grow while growing. Therefore, the two carbon fibers grow while forming a coil. At this time, the coil diameter, coil pitch, and coil length are controlled by the applied strength, waveform, and applied time of the electrostatic field.

By such a manufacturing method, coiled carbon fibers 10 having a large coil diameter and a large coil pitch and a long coil length can be obtained.

The effects exerted by the first embodiment will be described below.

(1) According to the coiled carbon fiber 10 of the first embodiment, the carbon fiber is formed in a coil shape, the coil diameter is substantially on the order of microns, and electromagnetic waves can be effectively absorbed and shielded. Excellent elasticity and high strength can be exhibited.

(2) According to the coiled carbon fiber 10 of the first embodiment, the reaction time, the type and particle size of the metal catalyst 20, the concentration of the gas used in the reaction, the reaction temperature, the voltage of the electrostatic field, and the substrate The coil diameter, coil pitch and coil length of the coiled carbon fiber 10 can be controlled by changing the distance between 19 and the rod-shaped electrode 23. Therefore, it is used as a wide range of electromagnetic wave absorbers, new electrode materials, energy conversion devices, microsensors, micromechanical devices, microfilters, high temperature 'high pressure' corrosion resistant 'elastic packing, catalyst carriers, antibacterial materials, adsorbents, etc. be able to.

(3) According to the coiled carbon fiber manufacturing apparatus 11 of the first embodiment, the substrate 19 is connected to the high voltage electrostatic field generator 22 in the reaction vessel 12. Therefore, an electrostatic field can be applied to the coiled carbon fiber 10, and the coiled carbon fiber 10 having a large coil diameter and coil pitch and a long coil length can be obtained. The yield of the coiled carbon fibers 10 can be improved.

Further, by applying an electrostatic field, the catalytic activity of the crystal plane of the metal catalyst 20 can be controlled, and the magnitude of the anisotropy can be adjusted. Therefore, the coil diameter can be increased by reducing the crystal plane anisotropy, and the coil diameter can be reduced by increasing the crystal plane anisotropy.

(4) According to the coiled carbon fiber manufacturing apparatus 11 of the first embodiment, since the inflow port 15 protrudes from the center upper peripheral surface of the reaction vessel 12 facing the substrate 19, the coil Acetylene, thiophene and hydrogen gas can be sprayed on the place where the carbon fibers 10 are growing. Therefore, the coiled carbon fiber 10 can be efficiently grown on the substrate 19.

(5) According to the coiled carbon fiber manufacturing apparatus 11 of the first embodiment, the outlet 17 is formed so as to protrude from the lower peripheral surface of the center of the reaction vessel 12 located on the back side of the substrate 19. I have. Therefore, acetylene, thiophene, and hydrogen gas introduced into the reaction vessel 12 are collected on the substrate 19, and the coiled carbon fibers 10 can be efficiently grown on the substrate 19.

(6) According to the coiled carbon fiber manufacturing apparatus 11 of the first embodiment, the injection ports 16 for injecting the sealing gas are formed one by one at both ends of the reaction vessel 12. For this reason, it is possible to prevent an extra or harmful influence of oxygen gas or the like from being applied to the reaction system on the substrate 19.

(7) According to the coiled carbon fiber manufacturing apparatus 11 of the first embodiment, the heater 18 is attached to the central peripheral surface of the reaction vessel 12. Therefore, the substrate 19 disposed in the center of the reaction vessel 12 can be heated uniformly, and the reaction can proceed smoothly.

(8) According to the coiled carbon fiber manufacturing apparatus 11 of the first embodiment, the distance between the substrate 19 and the inflow port 15 is set to be in the range of 2 to 20 min. . Therefore, the coiled carbon fibers 10 can be surely grown, and a decrease in yield can be prevented.

(9) According to the method for producing the coiled carbon fiber 10 of the first embodiment, the reaction temperature is set in the range of 600 to 950 ° C, so that the reaction of the coiled carbon fiber 10 is maintained. And the yield can be improved.

(Second embodiment)

Next, a second embodiment will be described. Note that the description of the second embodiment will focus on the differences from the first embodiment.

In the coiled carbon fiber manufacturing apparatus 11 of the second embodiment, a substrate 19 for growing the coiled carbon fiber 10 of the first embodiment is formed of a wire 37. The wire 37 is formed of a metal wire such as stainless steel, nickel, titanium and tungsten, a carbon fiber, a ceramic fiber such as alumina or silicon carbide (SiC), and does not contain copper. The same metal catalyst as in the first embodiment is used as the metal catalyst 20, and is applied to the entire peripheral surface of the wire 37.

As shown in FIG. 3, the reaction vessel 12 is formed in a tubular shape and arranged vertically. An opening 13 at one end of the reaction vessel 12 is closed by an insulating rubber stopper 14. The other end is a bifurcated branch pipe 38, and a scraper 39 made of an insulating material is attached to the root of both branch pipes 38. With this scraper 39, the coiled carbon fiber 10 can be scraped off and distributed to both branch pipes 38.

The pair of opening / closing dampers 40 are detachably attached to the distal ends of the branch pipes 38, respectively. Then, the opening / closing damper 40 on the base side of the reaction vessel 12 is detached, and the opening / closing damper 40 on the tip side is inserted, so that the inside of the reaction vessel 12 is shut off and the opening / closing damper 40 on the front end side is closed. The coiled carbon fiber 10 that has fallen in the branch pipe 38 is supported. Subsequently, as shown in FIG. 4, the opening / closing damper 40 on the base side is inserted, and the opening / closing damper 40 on the tip side is detached, so that the opening / closing damper 40 on the tip side is cut off while the inside of the reaction vessel 12 is shut off. The coiled carbon fiber 10 supported above can be dropped. A hopper 41 as a product receiver is installed at a position below the tip of each branch pipe 38 so as to accommodate the coiled carbon fiber 10.

The upper end of the wire 37 is wound around a wire roll 42 on the supply side disposed above the insulating rubber stopper 14 at one end of the reaction vessel 12. The lower end of the wire rod 37 passes through the scraper 39 and is wound around the wire roll 43 on the collection side outside the reaction vessel 12. To be collected.

The high-voltage electrostatic field generator 22 is arranged at a location remote from the reaction vessel 12 and is in contact with the wire 37 via the connection line 21. Then, the electrostatic field generated from the high-voltage electrostatic field generator 22 is applied to the wire 37. The ground plate 44 is attached in a ring shape so as to cover the peripheral surface of the heater 18, and is grounded via a ground wire 45. Now, as shown in FIG. 3, the coiled carbon fiber 10 grows on the wire 37 in the reaction vessel 12 in the same manner as in the first embodiment. At this time, the coiled carbon fibers 10 grow in all directions from the peripheral surface of the wire rod 37. Then, as shown in FIG. 4, when the wire 37 is wound by the wire roll 43 on the collection side, the wire 37 on which the coiled carbon fiber 10 grows and is attached is wound. At this time, the coiled carbon fiber 10 is scraped off by the scraper 39 and falls down each branch pipe 38 3. Then, by opening and closing the opening / closing dampers 40 at the ends of the branch pipes 38 alternately, the coiled carbon fibers 10 are collected in the hopper 41 內 while the inside of the reaction vessel 12 is shut off.

The effects exerted by the second embodiment will be described below.

(1) According to the coiled carbon fiber manufacturing apparatus 11 of the second embodiment, since the wire 37 is used as a place for growing the coiled carbon fiber 10, the wire 37 is omnidirectional from the peripheral surface of the wire 37. Coiled carbon fibers 10 can be grown in a larger area, and a larger amount of coiled carbon fibers 10 can be obtained per unit area than when substrate 19 is used.

(2) According to the coiled carbon fiber manufacturing apparatus 11 of the second embodiment, the wire 37 is wound around the rolls 42 and 43 so that it can be continuously supplied, so that a long reaction time is required. And a large amount of coiled carbon fibers 10 can be obtained by continuous reaction. Further, since it is not necessary to replace the substrate 19 once, the manufacturing time can be reduced and the manufacturing cost can be reduced.

(3) According to the coiled carbon fiber manufacturing apparatus 11 of the second embodiment, one end of the reaction vessel 12 is divided into two branches to form a branch pipe 38, and a scraper 39 is provided at the base of the branch pipe 38. Installed. Therefore, the coiled carbon fiber 10 grown on the wire 37 can be easily collected by winding the wire 37 through the scraper 39. Furthermore, since it passes through each branch pipe 38 and falls into the hopper 41, the coiled carbon fiber 10 can be reliably recovered. (4) According to the coiled carbon fiber manufacturing apparatus 11 of the second embodiment, when two opening / closing dampers 40 are attached to one branch pipe 38, one opening / closing damper 40 is detached. Then, the other open / close damper 40 can be kept inserted. Therefore, the coiled carbon fibers 10 can be recovered while the reaction vessel 12 is kept closed.

(Third embodiment)

Next, a third embodiment will be described. Note that, in the third embodiment, a description will be given focusing on a portion different from the second embodiment.

An apparatus 11 for manufacturing coiled carbon fibers according to the third embodiment has a substrate 19 where the growth of the coiled carbon fibers 10 is formed of the same wire rod 37 as in the second embodiment. As shown, the opening 13 at the lower end of the reaction vessel 12 is closed by an insulating rubber stopper 14. The upper end is a reduced diameter portion 46 that decreases in diameter upward. The length of the upper end of the reaction vessel 12 and the inlet 16 on the upper end side is longer than the length of the tip of the reaction vessel 12 and the inlet 16 of the first embodiment. Further, between the upper end of the reaction vessel 12 and the injection port 16, another injection port 47 is formed so as to protrude on the peripheral surface, and the sealing gas is introduced similarly to the injection port 16. .

The plurality of sealing materials 48 are formed in a conical shape at regular intervals by a metal plate, and their outer peripheral edges are joined to the inner peripheral surface of the reaction vessel 12. At each end, a passage hole 49 for allowing the wire 37 to pass is formed. A labyrinth seal 50 is provided by the plurality of seal materials 48. The labyrinth seal 50 is attached to the upper end and the intermediate part in the reaction vessel 12 so that leakage of the reaction gas or the seal gas can be minimized.

The wire 37 is wound around a wire roll 42 on the supply side at the lower end of the reaction vessel 12. The upper end of the wire rod 37 passes through the inside of the reaction vessel 12, passes through the reduced diameter portion 46 of the upper end of the reaction vessel 12, and is collected by the wire rod holder 43 on the collection side. . The coiled carbon fiber 10 is formed downward at the reaction site because the reaction vessel 12 is suspended. Then, by collecting the wire 37 upward, the coil-shaped carbon fibers 10 are continuously long and formed into one long fiber. Product collection roll 5 1 is the wire on the collection side It is arranged at a position adjacent to the use roll 43 so that the grown long coiled carbon fibers 10 can be collected.

The scraper 52 is formed in an inverted conical shape by a metal plate, and a through hole 53 for passing a wire is formed at the tip of the scraper. Then, the scraper 52 is arranged at a position where the wire rod 37 coming out of the passage hole 49 of the reduced diameter portion 46 can be passed through the through hole 53, and at the same time as passing the wire rod 37, The coiled carbon fiber 10 grown on the wire 37 can be scraped off. Then, at the same time as the wire rod 37 is collected, one long coiled carbon fiber 10 grown on the wire rod 37 is scraped off by the wire rod 37 and collected by the product collection roll 51. You.

Now, the coiled carbon fiber 10 grows on the wire 37 in the reaction vessel 12 in the same manner as in the first embodiment. At this time, the reaction vessel 12 is formed to be long toward the upper end, and since the production apparatus 11 is suspended, the coiled carbon fibers 10 grown on the wire 37 continuously flow downward due to gravity. It is formed.

Then, the wire 37 is wound by the wire roll 43 on the collecting side, and the continuously grown coiled carbon fiber 10 is scraped by the scraper 52 and collected by the product collecting roll 51.

The effects exerted by the third embodiment will be described below.

(1) According to the coiled carbon fiber manufacturing apparatus 11 of the third embodiment, since the reaction vessel 12 is upright, the coiled carbon fiber 10 grown on the wire 37 is gravity-driven. It can be formed continuously downward. Therefore, the length of the coiled carbon fiber 10 can be increased to the order of m.

(2) According to the coiled carbon fiber manufacturing apparatus 11 of the third embodiment, since the labyrinth seal 50 is provided in the reaction vessel 12, leakage of the reaction gas or the seal gas is minimized. And the reaction can proceed smoothly.

(3) According to the coiled carbon fiber manufacturing apparatus 11 of the third embodiment, the coiled carbon fiber 10 grown on the wire 37 can be scraped off by the scraper 52. Further, the wire rod 37 is collected by the wire rod 43 on the collection side, and one long coiled carbon fiber 10 grown on the wire rod 37 can be collected by the product collection roll 51. Hereinafter, the present invention will be described more specifically with reference to examples.

In Examples 1 to 3, the average voltage, the coil pitch, and the coil length of the obtained coiled carbon fibers 10 were compared by changing the static voltage applied to the substrate 19 made of graphite.

(Example 1)

As shown in Fig. 1, nickel powder 20 with an average particle size of 5 μm was placed in the center of a horizontal thermochemical vapor phase synthesizer 12 consisting of a transparent quartz tube with a radius of 60 mm and a length of 100 mm. The coated graphite substrate 19 was set. Then, acetylene, thiophene, and hydrogen gas were introduced from an inlet 15 at the upper center of the reaction vessel 12, and nitrogen gas was introduced as a sealing gas from inlets 16 at both ends of the reaction vessel 12. The reaction was performed at 750 ° C for 2 hours. The gas flow rates were acetylene at 60 O mlZ, thiophene at 12 ml / min, hydrogen at 140 O mlZ, and nitrogen at 100 O mlZ. The distance between the inlet 15 for the source gas and the like and the substrate 19 was 1 O mm. During the reaction, a 500 V static voltage was applied to the substrate 19 to ground the rod-shaped electrode 23.

As a result, very densely wound coil-shaped carbon fibers 10 with an average diameter of about 5 m, a coil pitch of 0.2 / im and a length of 4 mm were converted to 95 monoliters of acetylene as raw material. % Yield.

(Example 2)

The reaction was carried out under the same conditions as in Example 1 except that a static voltage of 1500 V was applied to the graphite substrate 19.

The yield of the coiled carbon fibers 10 based on the raw material acetylene was 90 mol%. The average diameter of the coil was 50 / im, the pitch of the coil was 2 μm, and the length of the coil was 2 mm

(Example 3)

The reaction was carried out under the same conditions as in Example 1 except that a static voltage of 500 V was applied to the graphite substrate 19. The yield of the coiled carbon fiber 10 based on the raw material acetylene was 70 mono / ⁰ . Met. The average Koinole diameter was 500 m, the Koinole pitch was 20 m, and the Koinole length was 0.5 ram.

The higher the applied electrostatic voltage, the higher the yield of the coiled carbon fiber 10 is. It was shown that the diameter and coil pitch approached the micron order, and the coil length became longer.

Next, in Examples 4 to 6, an electrostatic field was applied to the rod-shaped electrode 23 on the top of the graphite substrate 19, and the graphite substrate 19 was grounded. Then, the distance between the rod-shaped electrode 23 and the graphite substrate 19 is changed, and the voltage of the electrostatic field is changed to grow the coiled carbon fiber 10. The average coil diameter, coil pitch and coil length were compared.

(Example 4)

A static voltage of 500 V is applied to a 2 mm-diameter rod-shaped electrode 23 set at a position 3 mm above the graphite substrate 19, the substrate 19 is grounded, and the reaction time is reduced to 30%. The reaction was carried out under the same conditions as in Example 1 except that the reaction time was changed to minutes.

The yield of the coiled carbon fiber 10 based on the raw material acetylene was 95 mol. /. Met. The average Koinole diameter was 5 μm, the Koinole pitch was 0.2 / m, and the Koinole length was 0.5 mni.

(Example 5)

Example 1 was repeated except that a 500 V static voltage was applied to a rod-shaped electrode 23 having a diameter of 2 mm, which was set at a position 5 bands above the graphite substrate 19 and the reaction time was 30 minutes. The reaction was performed under the same conditions as described above.

The yield of coiled carbon fiber 1 ° based on the raw material acetylene was 80 moles ⁰ /. Met. The average Koinole diameter was 4 μm, the Koinole pitch was 0.2 μπι, and the Koinole length was 0.5 mm.

(Example 6)

Example 1 except that a static voltage of 150 V was applied to the rod electrode 23 of diameter 2 set at five positions above the graphite substrate 19 and the reaction time was set to 30 minutes. The reaction was performed under the same conditions as described above.

The yield of the coiled carbon fibers 10 based on the raw material acetylene was 80 mol%. The average coil diameter was 100 μm, the coil pitch was 2 // m, and the coil length was 0.2 bacteria.

If the distance between the graphite substrate 19 and the rod electrode 23 to which the electrostatic field is applied is long, It was shown that the yield of the coiled carbon fibers 10 was reduced and the average coil diameter was increased. Further, if the distance between the graphite substrate 19 and the rod-shaped electrode 23 to which the electrostatic field is applied is long and the voltage of the applied electrostatic field is low, the yield of the coiled carbon fiber 10 decreases, It was shown that the coil diameter, coil pitch, and coil length also deteriorated.

Next, in Example 7 and Example 8, the distance between the inlet 15 of the raw material gas and the like and the tip of the grown coiled carbon fiber 10 was always about 3 mm so that the coiled carbon Fiber 10 was grown.

(Example 7)

Set a graphite substrate 19 coated with nickel powder 20 with an average particle size of 5 m in the center of a reaction vessel 12 made of a transparent quartz tube with a diameter of 60 dishes and a length of 100 Oinm. did . Then, a mixed gas of acetylene, thiophene and hydrogen was introduced from the inlet 15, nitrogen gas was injected from the inlet 16 as a seal gas, and the reaction was carried out at 75 ° C. for 20 hours. The gas flow rates were 50 m 1 Z for acetylene, 1 ml for thiophene, 400 ml for hydrogen, and 100 ml for nitrogen. The reaction was performed while continuously lowering the position of the substrate 19 with the growth of the coil so that the distance between the inlet 15 of the raw material gas and the substrate 19 was always about three legs. During the reaction, a static voltage of 500 V was applied to the substrate 19.

As a result, very densely wound long coiled carbon fibers 10 with an average Koinole diameter of about 5 μm, a Koinole pitch of 0.2 / m, and a length of 3 cm were 95% of the raw material acetylene. Mol ⁰ /. Was obtained in a yield of

(Example 8)

The reaction was carried out under the same conditions as in Example 7, except that the reaction time was set to 200 hours. As a result, a very densely wound long coiled carbon fiber 10 with an average coil diameter of about 5πι, a coil pitch of ◦ .2 / m, and a length of 3 Ocm was 90% of the raw material acetylene. Obtained in a yield of% monol.

If the distance between the raw material gas inlet 15 and the tip of the grown coiled carbon fiber 10 is always about 3 dragons, the average coil diameter, coil pitch and coil length are all good. It was shown that carbon fiber 10 was obtained. But the reaction time Was too long, the yield was shown to decrease.

(Example 9)

As shown in FIG. 5, in Example 9, the reaction vessel 12 was set upright, and the wire rod 37 was used as a place for the growth of the coiled carbon fiber 10 instead of the graphite substrate 19. The reaction was continuously carried out while winding up 7. A product recovery roll 5 1 for winding the coiled carbon fiber 10 and a wire rod 43 on the recovery side for winding the wire 3 7 are placed outside the reaction vessel 1 2, and the material gas inlet 15 The distance of the tip of the coiled carbon fiber 10 was kept at about 3 band, and the reaction was performed for 2000 hours while continuously winding the grown coil. Otherwise, the reaction was carried out under the same conditions as in Example 8.

As a result, a very densely wound long coiled carbon fiber 10 with an average coil diameter of about 5 μm, a coil pitch of 0.2 / xm, and a length of 30 Ocm was used for the raw acetylene. 90 moles ⁰ /. Was obtained in a yield of

The distance between the inlet 15 of the raw material gas and the tip of the grown coiled carbon fiber 10 should always be about 3 bands, and the coiled carbon fiber 10 will not react for a long time in the reaction vessel 12 Thus, it was shown that the coiled carbon fiber 10 continuously grown could be obtained by such a recovery.

The above-described embodiment can be embodied with the following modifications.

(1) The substrate 19 as a place where the coiled carbon fiber 10 grows is formed in a mesh shape with the wire 37. In addition, it should be formed in a belt shape using graphite.

When the wire 37 is formed in a mesh shape, a larger amount of coiled carbon fibers 10 can be grown than when the wire 37 is a single wire. When formed in a belt shape, a larger amount of coiled carbon fibers 10 can be grown than in the case of a single substrate 19.

(2) In the first embodiment, a metal catalyst 20 is applied to the rod-shaped electrode 23, an electrostatic field is applied, and a field where the coiled carbon fiber 10 grows is formed. Connect 4 to use as a ground plate.

Also in such a configuration, the coiled carbon fibers 10 can be grown from the rod-shaped electrodes 23.

(3) As shown in Fig. 6, the rod-shaped electrode 23 serving as ground is a conductive plate material. To form an annular shape, and attach it so as to cover the peripheral surface of the heater 18. Alternatively, the rod-shaped electrode 23 is formed in an annular shape from a conductive plate material, and is mounted so as to cover the peripheral surface of the heater 18, and the reaction vessel 12 is grounded.

With such a configuration, the reaction gas can be efficiently circulated in the reaction vessel 12, and the reaction gas can be collected on the substrate 19 to improve the reaction efficiency.

Claims

The scope of the claims

1. Formed as a coil from carbon fiber, the fiber diameter is 0.1 to 5 μιη, the coil diameter is 0.1 to 2000 μιη, the coil pitch is 0 to 50 / Hi, and the coil length is Ι Ο Ο μπ! A coiled carbon fiber containing a coil having a right-handed double helical structure and a coil having a left-handed double helical structure.

2. The coiled carbon fiber according to claim 1, wherein the coil having the right-handed double helical structure and the coil having the left-handed double helical structure are present in a ratio of approximately one to one.

3. Hydrocarbon or carbon monoxide is heated to a temperature of 600 to 950 ° C in the presence of a metal catalyst, a gas of a compound of group 15 or 16 of the periodic table, hydrogen gas and a sealing gas. A method for producing coiled carbon fiber that forms an electrostatic field upon heating and decomposes hydrocarbon or carbon monoxide.

4. The metal catalyst according to claim 3, wherein the metal catalyst is nickel, titanium or tungsten, the compound is a compound containing a sulfur atom or a phosphorus atom, the hydrocarbon is acetylene, and the seal gas is nitrogen or helium gas. A method for producing a coiled carbon fiber.

5. The method for producing a coiled carbon fiber according to claim 3 or 4, wherein the electrostatic field is a non-variable electrostatic field or a variable electrostatic field.

6. The method according to claim 5, wherein the electrostatic field is a high-pressure electrostatic field having a superimposed waveform including a harmonic component.

7. The gas concentration of the compounds of Groups 15 and 16 of the periodic table according to Claim 3 or Claim 4, wherein the gas concentration in the reaction atmosphere is within a range of 0.01 to 5% by volume. A method for producing a coiled carbon fiber.

8. A reaction vessel having a heater is provided with an inlet and an outlet for flowing hydrocarbon gas or carbon monoxide gas, gas of a compound of group 15 or 16 of the periodic table and hydrogen gas, and a seal. In addition to providing an inlet for injecting gas, a base material for forming a high-voltage electrostatic field or a conductor at a predetermined distance from the base material is arranged in the reaction vessel, and the coiled carbon fiber is placed on the base material. An apparatus for producing coiled carbon fibers configured to grow.

9. The apparatus for producing coiled carbon fibers according to claim 8, wherein the substrate is movably disposed, and the substrate is moved in accordance with the growth of the coiled carbon fibers.

10. The apparatus for producing coiled carbon fibers according to claim 8, wherein the base material is a wire or a band.

11. The wire according to claim 8, wherein the base material is made of a wire or a strip, and a wire roll for winding and supplying the wire or the strip is disposed outside one end of the reaction vessel. An apparatus for producing coiled carbon fibers in which a wire roll for winding and recovering a wire or a strip is arranged outside the side.

12. The claim according to claim 8, wherein the base material is made of a wire or a strip, and a branch pipe for distributing the coiled carbon fiber is formed at one end of the reaction vessel, and a wire or a strip is formed at a root of the branch pipe. Equipment for manufacturing coiled carbon fiber equipped with a scraper for removing coiled carbon fiber grown on the material.

13. The apparatus for producing coiled carbon fibers according to claim 8 or 9, wherein a distance between the substrate and the inflow port is set in a range of 2 to 20 feet.

14. The apparatus for producing coiled carbon fibers according to claim 8, wherein the base material is a substrate having a surface coated with a catalyst made of a metal powder.