JP3340591B2 - Carbon fiber bundle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous carbon fiber bundle which is an electrode and is a raw material of fullerene, which is suitable for producing fullerene by an arc discharge method. The arc discharge is stabilized by optimizing the configuration and form of the continuous carbon fiber bundle, and as a result, continuous carbon fibers for producing fullerenes can be produced in a continuous manner with a high yield. About a bunch.

[0002]

2. Description of the Related Art Fullerene is a generic name for spherical molecules composed of only carbon atoms. For example, 60 carbon atoms are formed of sugar molecules as described as "saccharball-like molecules".
It is known that a ball-shaped molecule is arranged and bonded to each vertex of a ball to form a hollow spherical molecule.

[0003] Since the existence of fullerene was confirmed in 1985, various synthetic methods have been studied. It is said that a carbonaceous raw material typified by natural graphite is used as the raw material, which is decomposed and sublimated by heating at a high temperature of 3000 ° C. or more to form atomic carbon, which is recombined to produce fullerene. I have. As a method of high temperature heating in the production of fullerene from a carbonaceous raw material, many proposals have conventionally been made by an abrasion method using a laser, a resistance heating method, a high-frequency induction heating method, an arc discharge method or a method combining these. Has been made.

Among the fullerene production methods, a fullerene production method using a high temperature by an arc discharge method is to obtain a high temperature of 3000 ° C. or more in a short time by local arc discharge between electrodes in an inert gas atmosphere. It is possible to synthesize fullerene from a carbon raw material with a relatively simple apparatus, and has the advantage that the total yield from the carbon raw material is 1% or more, which is higher than other methods. Many proposals have been made as disclosed in JP-T-5-502213 and JP-A-5-116925.

[0005]

Problems to be Solved by the Invention Japanese Patent Publication No. 5-502
No. 213 discloses a basic technique for producing fullerene by an arc discharge method performed in an evacuated processing chamber at a pressure of about 50 to 400 torr below atmospheric pressure. However, according to the description of the publication, it is clarified that a graphite rod having a short length (about 1 cm in length) having a diameter of 0.25 inch is generally used as a carbon raw material. Therefore, since the carbon material described in the publication is short, it is possible to obtain a large amount of fullerene by continuously processing the carbon material without breaking the decompression condition in the processing chamber, that is, without returning to the atmospheric pressure. Can not.

Assuming that an attempt is made to produce a large amount of fullerenes by expanding this method, for example, even if the carbon raw material is changed from a short to a long graphite rod, the carbon raw material becomes rigid. Since it is a long graphite rod, there is a problem that a large processing chamber corresponding to the size of the carbon raw material is required to accommodate the carbon raw material,
It is disadvantageous in cost.

In Japanese Patent Application Laid-Open No. Hei 5-116925, a long carbon fiber wire is used as a carbon raw material.
A method for producing fullerene by continuously supplying this carbon material and performing arc discharge treatment has been shown,
This method states that fullerenes can be obtained in large quantities. However, the publication does not examine what physical and morphological characteristics of a long carbon fiber wire used as a raw material can synthesize fullerene with high yield.

Accordingly, the present invention examines the physical characteristics and morphological characteristics of carbon fibers from the viewpoint of raw materials for continuously and efficiently synthesizing fullerenes by an arc discharge method, and considers the efficient arc. -To provide a raw material for producing fullerenes by a spark discharge method.

[0009]

The continuous carbon fiber bundle for producing fullerenes by the arc discharge method of the present invention for solving the above problems has a volume resistivity of 5 × 10 ^-2 Ω · cm or less and A continuous carbon fiber bundle having a diameter of 3 mm or more produced by bundling single fibers of carbon fibers having a diameter of 1 to 100 μm, wherein the tensile elastic modulus increases radially from the center of the continuous carbon fiber bundle. And the volume resistivity is substantially the same or lower.

[0010] The continuous carbon fiber bundle of the present invention comprises an inner layer made of carbon fibers inside, and an outer layer made of carbon fibers covering the outside of the inner layer. The outer layer has a tensile modulus of elasticity of the inner layer. And the volume resistivity of the outer layer is substantially equal to or lower than that of the inner layer.

Further, the continuous carbon fiber bundle for producing fullerene by the arc discharge method of the present invention, which is different from the above, comprises a core formed of carbon fibers at the center thereof, and carbon fibers covering the outside of the core. Inner layer, and an outer layer composed of carbon fibers covering the outside of the inner layer, wherein the tensile modulus of the inner layer is higher than that of the core, and the volume resistivity of the inner layer is substantially equal to or higher than that of the core. The inner layer has a tensile modulus of elasticity higher than that of the inner layer, and the outer layer has a volume resistivity substantially equal to or lower than that of the inner layer.

Further, a continuous carbon fiber bundle for producing fullerene by an arc discharge method according to the present invention, which is different from the above, comprises a core made of fibers other than carbon fibers selected from inorganic fibers and organic fibers. Volume resistivity 5 × 1 covering the outside of the core
0 ^inner layer ^-2 Omega · cm and in diameter or less, which are focused carbon fiber monofilament of 1 to 100 [mu] m, is and diameter less volume resistivity of 5 × 10 ^{-2 Ω} · cm covering the outer of the inner layer 1
A continuous carbon fiber bundle having a diameter of 3 mm or more comprising an outer layer formed by bundling monofilament carbon fibers of 100 μm, wherein the tensile modulus of the inner layer is higher than that of the core, and the volume resistivity of the inner layer is The core is substantially equal to or lower than the core, and the tensile modulus of the outer layer is higher than that of the inner layer, and the volume resistivity of the outer layer is substantially equal to or lower than that of the inner layer. And

[0013] As described above, the continuous carbon fiber bundle of the present invention has a tensile modulus higher in the radial direction from the center of the cross section and has a volume resistivity substantially equal to or smaller in the radial direction from the center. When the arc discharge is performed using this continuous carbon fiber bundle as one electrode, the arc generated is stable even in a pressure region of 100 mmHg or more of the inert gas. The yield of fullerene synthesized with the decomposition and rearrangement of the continuous carbon fiber bundle at a high temperature of 3000 ° C. or higher is increased.

Conversely, if fibers having a high volume resistivity are arranged radially from the center of the cross section of the carbon fiber bundle, the
The discharge becomes unstable, and as a result, the synthesis yield of fullerene decreases. For example, carbon fiber strands of the same performance are used for the core / inner layer / outer layer, and there is no anisotropy in the tensile modulus in the radial direction, or the tensile modulus decreases in the radial direction from the center, or the center thereof. When fullerene is produced by performing arc discharge in an inert gas atmosphere using a continuous carbon fiber bundle whose volume resistivity increases in the radial direction as a raw material, the pressure of the inert gas becomes 50%.
Arc discharge becomes unstable in the region of mmHg or more, and the yield of fullerene tends to decrease to 1% or less, which is not preferable.

The volume resistivity of the carbon fiber corresponds to the tensile modulus of the carbon fiber, and the fiber having a lower volume resistivity tends to have a higher tensile modulus. However,
Since the change in volume resistivity with respect to the tensile modulus is minute, when expressing that the volume resistivity decreases in the radial direction from the center of the continuous carbon fiber bundle, the tensile modulus clearly increases. Can be measured, but there is a case where there is a minute anisotropy of the volume resistivity that cannot be expressed as a measurement error in the actual measurement of the volume resistivity. It also contains continuous carbon fiber bundles that are declining. Therefore, to express that the volume resistivity decreases in the radial direction from the center of such a continuous carbon fiber bundle, in the continuous carbon fiber bundle of the present invention, the volume resistivity and the tensile elasticity are as described above. Identified by both rates.

The single carbon fiber constituting the continuous carbon fiber bundle of the present invention has a volume resistivity of 5 × 10 ^-2 Ω as described above.
Cm or less, and preferably those having a volume resistivity of 10 ⁻³ Ω · cm or less are used to increase the yield in synthesizing fullerene by arc discharge. Those whose volume resistivity is larger than 5 × 10 ⁻² Ω · cm
The carbon content of the carbon raw material does not become 96% or more, the graphite layer is not sufficiently developed, and the graphitic property is low. When such a carbon material having a low carbon content is used for producing fullerenes, the yield of fullerenes obtained by arc discharge decreases, which is not preferable. Although the cause is not clear, it is presumed that carbon materials with low graphitic nature do not decompose carbon to the atomic level during arc discharge, causing carbon particles to be scattered in relatively large units, resulting in lower fullerene yields. You.

As the form of the carbon fiber used in the continuous carbon fiber bundle of the present invention, for example, a braid, a woven fabric, a twisted yarn, a combined yarn, or a combination thereof can be used for the inner layer and / or the outer layer.

[0018] wherein the carbon fibers used in the layers of continuous carbon fiber bundles and continuous carbon fiber bundle consisting of the three layers of two layers, a volume resistivity of 5 × 10 ^-2 Ω · cm or less, preferably 10 ^- Monofilament carbon fibers having a diameter of ³ Ω · cm or less and having a diameter of 1 to 100 μm are used to increase the yield in synthesizing fullerene by arc discharge.

The continuous carbon fiber bundle of the present invention is composed of a large number of carbon fiber strands, and one carbon fiber strand generally collects 100 to 100,000 single fibers to form an epoxy resin-like strand. It is constituted by being bundled with a suitable sizing agent, and is used for, for example, a core, an inner layer, and an outer layer. The continuous carbon fiber bundle of the present invention has a tensile modulus of 35 tons / mm ² or more, a volume resistivity of 5 × 10 ⁻² Ω · cm or less, and a wide-angle X-ray diffraction. The distance between the (002) planes of graphite is 3.45.
Å It is preferable that it is not more than.

As an example of the layer structure of the continuous carbon fiber bundle of the present invention, FIG. 1 shows a continuous carbon fiber bundle having a layer structure of inner layer 1 / outer layer 2, and FIG. 1 shows a continuous carbon fiber bundle having the following layer configuration. Core 3, inner layer 1
By using the same or different types of fiber strands or an aggregate obtained by bundling them for the outer layer 2 and combining them so that the tensile elastic modulus and the volume resistivity defined above are satisfied, the tensile elastic modulus and the volume resistivity in the radial direction are increased. Anisotropy with respect to modulus can be provided.

The inner layer of the continuous carbon fiber bundle according to the present invention comprises:
Its tensile modulus is lower than that of the outer layer, and the volume resistivity of the inner layer is approximately equal to that of the outer layer or higher than that of the outer layer. The carbon fiber of the inner layer can be used in the form of a braid, a woven fabric, a twisted yarn, a knitting yarn, a yarn bundle, or a combination thereof. In this inner layer, a carbonaceous powder having a carbon content of 98% or more, A film or a short carbon rod may be included. In particular, the inner layer has a carbon fiber strand having a tensile modulus of 35 tons / mm ² or more, a volume resistivity of 5 × 10 ⁻² Ω · cm or less, and a wide angle X
It is preferable to use a carbon fiber having a plane spacing of (002) plane of graphite of 3.45 ° or less determined by line diffraction in order to synthesize fullerene with a yield from raw materials of 2% or more. Usually, it is preferable to use carbon fibers which have been carbonized at 2000 ° C. or higher as a raw material in order to efficiently synthesize fullerene. Even in the form of the carbon fiber bundle shown in FIGS. 1 and 2, carbonization treatment at 2000 ° C. or more is effective.

As the core of the continuous carbon fiber bundle of the present invention, a carbon fiber strand having a volume resistivity equal to or higher than that of the carbon fiber used for the inner layer and having a lower tensile modulus than the fiber used for the inner layer is used. . As long as the core has such resistivity or tensile modulus, inorganic fibers (for example, glass fibers or alumina fibers) and organic fibers, or insulating fibers having an electric resistivity in an insulating region may be used. However, it is desirable that the content of the continuous carbon fiber bundle is not more than 10%, which does not affect the yield of fullerene.

The outer layer in the continuous carbon fiber bundle of the present invention comprises:
The tensile modulus of the inner layer is higher than that of the inner layer, and the volume resistivity of the outer layer is substantially equal to or lower than that of the inner layer. The outer layer can be formed by continuously winding the outer side of the inner layer in a spiral shape with carbon fibers. As the carbon fibers used for the outer layer, carbon fibers plated with metal can be used. As the carbon fiber used for the outer layer, a braid, a woven fabric, a twisted yarn, a knitting yarn, a twine bundle or a combination thereof can be used as in the case of the carbon fiber of the inner layer. Good.

The inner layer and / or the outer layer is not limited to one layer, but may be a multilayer.

In the continuous carbon fiber bundle of the present invention, the preferable range of the effective cross-sectional area varies depending on the amount of electric power to be applied. 7m to increase the efficiency at
A cross-sectional area of at least m ² is preferred.

The continuous carbon fiber bundle of the present invention has an apparent fiber density of 0.5 g / cm ³ or more, more preferably 1.
An amount of 0 g / cm ³ or more is advantageous for increasing the synthesis efficiency of fullerene. To increase the apparent fiber density of a continuous carbon fiber bundle, braid, woven, twisted, knitted,
It is preferable to use it in the form of a yarn bundle or a combination thereof. More preferably, the continuous carbon fiber bundle in the present invention is wound strongly with a carbon fiber strand as an outer layer, thereby increasing the number of carbon fiber strands filled per unit cross-sectional area and increasing the apparent fiber density to 1.0 g / cm.
Can be raised to ³ or more.

The continuous carbon fiber bundle of the present invention has flexibility,
Since it is long, it can be wound around equipment such as a crane or bobbin densely and in large quantities, and can be compactly installed in the reaction system of a fullerene manufacturing apparatus by an arc discharge method.
Therefore, although it is a batch process, a large amount of raw material can be continuously supplied to the arc discharge site.
Fullerene can be synthesized continuously for a long period of time, which is advantageous in cost. Further, by using such a raw material, the size of the entire fullerene manufacturing apparatus becomes compact, and the fullerene manufacturing apparatus can be manufactured relatively inexpensively.

As the carbon fiber strand usable as a raw material for producing the continuous carbon fiber bundle of the present invention, commercially available carbon fiber strands can be used. For example, Vesfite HTA HM, U
M series (carbon fiber manufactured by Toho Rayon Co., Ltd.) or a carbon fiber strand having equivalent performance can be used.

As a specific example of the carbon fiber strand that can be used for the continuous carbon fiber bundle of the present invention, for example, a carbon fiber strand formed by bundling 12,000 single fibers having a diameter of 4 to 7 μm is a fiber weight. 0.4-0.8g /
m, specific gravity 1.7-2.0, tensile strength 200-800k
It has typical performance of gf / mm ² and a tensile modulus of elasticity of 20 to 80 ton / mm ² .

One example of the continuous carbon fiber bundle of the present invention is, for example, a method in which the core of the continuous carbon fiber bundle has a volume resistivity of 1 × 10 ⁻³ Ω · c.
m (tensile elastic modulus 35 ton / mm ² ), one carbon fiber strand (12,000 single fibers having a diameter of 7 μm twisted), and the inner layer has a volume resistivity of 7 × 10 ⁻⁴ Ω · cm (tensile elastic modulus 40). 40 tons / mm ² ) of carbon fiber strands (12,000 single fibers having a diameter of 5 μm twisted together), and the outer layer has a volume resistivity of 5 × 10 ⁻⁴ Ω · cm (tensile modulus of 60 tons / mm ² ). The surface of a bundle of 40 carbon fiber strands serving as an inner layer is formed of a carbon fiber strand serving as an outer layer using a single carbon fiber strand (having 12,000 single fibers having a diameter of 5 μm twisted) of 0.1 to 10 mm. A continuous carbon fiber bundle having a diameter of 5 mm wound up at a pitch can be used as a raw material for fullerene. When this carbon fiber bundle is attached as an electrode and discharged between a graphite counter electrode in an inert gas atmosphere, fullerene is synthesized from the carbon fiber bundle with a relatively high yield.

The fullerenes produced using the continuous carbon fiber bundle of the present invention include, for example, electric and electronic materials such as electrodes, sensors and electronic elements, magnetic materials such as toner, and the like.
It is effective as a raw material for pharmaceuticals, an optical material having a light conversion function, a superconducting material, an energy storage material and the like.

Fullere using the continuous carbon fiber bundle of the present invention
In the arc discharge method for synthesizing fullerene using the continuous carbon fiber bundle of the present invention, an inert gas is introduced after the reaction system is evacuated to a high vacuum of 10 ^-2 mmHg or less. Then, arc discharge is caused between the continuous carbon fiber bundle of the present invention used as an arc discharge electrode and a counter electrode (mainly a graphite plate) in an inert gas atmosphere, and the carbon raw material is heated at a high temperature accompanying the discharge. This is a method of producing fullerene, which is a spherical molecule of carbon, by decomposing to the atomic level and subsequently rearranging carbon. In the method for producing fullerenes by the arc discharge method using the continuous carbon fiber bundle as a raw material of the present invention, the yield of fullerene from the raw material is relatively higher than other methods, and the yield of 1% or more is stably obtained. Can be secured.

In the method for producing fullerenes by the arc discharge method, a part of the continuous carbon fiber bundle used as an electrode becomes soot-like black powder by the arc discharge decomposition and scatters in the reaction system. On one counter electrode side, a part of carbon is vapor-deposited, grows as a deposit, and adheres. The fullerenes are present in the scattered soot in a ratio of about 5 to 20% by weight. The soot is collected, and the soot is immersed in an organic solvent such as toluene, soot is dissolved in the organic solvent. And the part that does not melt. The presence of fullerene is easily recognized by dissolving it in an organic solvent and coloring the solution.

The hula are dissolved in an organic solvent - Len acids are high molecular weight hula - are those containing alkylene such as, for example, C _60
C70 or _C78 are mixed. The preparation of fullerenes by arc discharge method using a continuous carbon fiber bundle of the present invention, usually, hula - C ₆₀ as the alkylene compound is contained about 80% and the remaining components of the high molecular weight, such as C ₇₀ or C ₇₈ Fullerene is mixed.

The fullerene solution obtained by filtering off soot components that are insoluble in the organic solvent is passed through a column such as an activated carbon column to separate and purify high-molecular-weight fullerenes therefrom. Obtained as ₆₀ . Alternatively, C ₆₀ , by a separation and purification method such as high performance liquid chromatogram.
Components such as C ₇₀ or C ₇₈ can be collected in minutes alone.

In order to synthesize fullerene efficiently, the reaction system in which arc discharge is performed is filled with an inert gas, and the raw material is arc-discharged under the atmosphere to obtain the continuous carbon fiber bundle of the present invention. Is preferably performed. Specifically, before arc discharge of the continuous carbon fiber bundle, 10 ^-2
After a high vacuum of not more than mmHg, 10-1000 ml /
While an inert gas is continuously flowed at a flow rate of a minute, the gas is evacuated and balanced by a vacuum pump, and discharge decomposition is performed under a condition where the pressure in the system is kept constant. The pressure is 5
The range is preferably in the range of mmHg to 500 mmHg.

As the inert gas, helium, argon, krypton, or a mixed gas thereof is used.

The power applied to the carbon source for discharging is:
In order to efficiently synthesize fullerene, a voltage of 10 to 100
V, a current density of 100 to 1000 A / cm ² is preferably passed. The current used for discharging may be AC or DC.

[0039]

【Example】

Example 1 For the continuous carbon fiber bundle of Example 1, Vesfite HM35-12K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.8 g) was used as the material of the inner layer. / M, tensile modulus: 35 ton / mm
^2. Volume resistivity: 1.0 × 10 ⁻³ Ω · cm, single fiber diameter: 6.7 μm, d (002) = 3.43 °)], and 50 carbon fiber strands 20 m long are bundled. To the inner layer. The outer side of the inner layer made of the bundle of carbon fiber strands is coated with Vesfight UM46-12K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.
4 g / m, tensile elasticity: 43 ton / mm ² , volume resistivity: 1.0 × 10 ⁻³ Ω · cm, single fiber diameter: 4.5 μm
m, d (002) = 3.42 °)], the outer layer is formed so as to be wound tightly on the inner layer made of the carbon fiber strand bundle at a winding pitch of 5 mm to cover, and the apparent fiber density is about A continuous carbon fiber bundle of Example 1 having a diameter of 1.0 mm / cm ³ and a diameter of 7 mm was produced.

FIG. 3 shows an example of a fullerene producing apparatus utilizing arc discharge. In FIG. 3, reference numeral 11 denotes a carbon material supply device such as a creel or bobbin which holds a long flexible carbonaceous material 12 by winding or the like. Reference numeral 13 denotes a transfer device that can transport the carbonaceous raw material 12 supplied from the carbonaceous raw material supply device 11 and guide the carbonaceous raw material 12 to an arbitrary position on the counter electrode 14. For example, as illustrated in FIG. used. The counter electrode 14 has a disk shape and is rotatable, and the tip of the carbonaceous raw material 12 conveyed from the conveyance device 13 that is suspended by its own weight is opposed to the disk-shaped horizontal surface of the counter electrode 14. . Around the counter electrode 14, a soot receptacle 15 for collecting the scattered fullerenes is surrounded.

The carbonaceous raw material supply device 11 and the transfer device 1
3, the counter electrode 14 and the soot receiver 15 are installed in a processing chamber 16 capable of maintaining a high vacuum state. Processing chamber 1
In the wall of 6, an exhaust port 20 is provided through a vacuum pump 21 for exhausting the gas in the processing chamber 16 to create a high vacuum state. An inert gas inlet 18 is provided to communicate with an inert gas cylinder 19 for providing an inert gas atmosphere having the above gas pressure. In order to cool the counter electrode 14 and the tip of the carbonaceous raw material 12, stabilize the arc discharge and increase the yield of fullerene, the inert gas inlet 1 introduced into the processing chamber 16
The tip of 8 is provided close to where these arc discharges occur. The transfer device 13 and the counter electrode 14
Is configured to be supplied with power from a power supply 17 provided outside the processing chamber 16.

Using the fullerene manufacturing apparatus shown in FIG. 3, an AC power supply was used as the power supply 17 and the current was set to 90 A and the voltage to 20 V. The continuous carbon fiber bundle of the first embodiment is used as the carbonaceous raw material 12, and the continuous carbon fiber bundle is wound around the carbonaceous raw material supply device 11 (clear) in the processing chamber 16. It was set apart so that the distance between the tip of the continuous carbon fiber bundle and the counter electrode 14 was 10 mm through the wire.

After installing the continuous carbon fiber bundle, the processing chamber 16
Was closed and the system was evacuated with a vacuum pump. The pressure in the system was adjusted to 1 × 10 ^-2 mmHg, and then helium gas was introduced into the system. The helium gas flow rate was adjusted to 300 by balancing the flow rate of the helium gas and the evacuation by the vacuum pump.
ml / min and the pressure was set at 30 mmHg.

The power supply 17 was turned on, the feed roller was turned, and the continuous carbon fiber bundle was moved toward the counter electrode 14 at a feed speed of about 10 mm / min. Discharge started after about 60 seconds, and a continuous carbon fiber bundle was continuously supplied at a feed speed of 5 to 10 mm / min while observing a change in the current value. The voltage value at the time of discharge was 18 to 19 V and the current value was 88 to 90 A. During the discharge, the voltage value and the current value did not change.

After operating for about 5 hours to perform the discharge treatment, the power supply 17 was turned off, left for 30 minutes, and cooled. The inside of the system was returned to the atmospheric pressure, and soot collected in the soot receiver 15 was collected. The amount of soot collected was 30 g. The total weight of the discharge-decomposed raw material was 62 g. The collected soot was immersed in toluene to dissolve the fullerenes contained in the soot in toluene. The weight of the extracted fullerenes was 1.5 g, and the yield from the raw materials was 2.4%.

The characteristics of the continuous carbon fiber bundle of Example 1, the fluctuation range of the current and voltage and the yield of fullerene when fullerene was produced using the same are shown in Table 1 below.

Example 2 The continuous carbon fiber bundle of Example 2 was made of Vesfite HTA-
5 g / m braided with 3K [trade name: carbon fiber manufactured by Toho Rayon Co., Ltd.] and heat-treated at 2800 ° C. for 5 minutes in a high-temperature furnace [tensile elastic modulus: 54 tons / mm ² , Volume resistivity: 9.0 × 10 ⁻⁴ Ω · cm, single fiber diameter: 6.
5 μm, d (002) = 3.41 °] and used as an inner layer. The outside of this inner layer is Vesfight UM63-12K
[Product name: Carbon fiber strand of Toho Rayon Co., Ltd. (fiber weight: 0.4 g / m, tensile modulus: 62 tons /
mm ² , volume resistivity: 7.0 × 10 ⁻⁴ Ω · cm, single fiber diameter: 4.5 μm, d (002) = 3.40 °)] and a single fiber is wound on the carbon fiber strand bundle at a winding pitch of 5 mm. The outer layer was formed so as to be wound tightly and covered to obtain a continuous carbon fiber bundle of Example 2 having an apparent fiber density of about 0.80 g / cm ³ and a diameter of 5 mm.

Using the fullerene manufacturing apparatus shown in FIG. 3, an AC power supply was used as the power supply 17, and the current was set to 90 A and the voltage to 20 V. The continuous carbon fiber bundle according to the second embodiment is used as the carbonaceous raw material 12, and the continuous carbon fiber bundle is wound around the carbonaceous raw material supply device 11 (clear) in the processing chamber 16. It was set apart so that the distance between the tip of the continuous carbon fiber bundle and the counter electrode 14 was 10 mm through the wire.

After installing the continuous carbon fiber bundle, the processing chamber 16
Was closed and the system was evacuated with a vacuum pump. The pressure in the system was adjusted to 1 × 10 ^-2 mmHg, and then helium gas was introduced into the system. The helium gas flow rate was adjusted to 300 by balancing the flow rate of the helium gas and the evacuation by the vacuum pump.
ml / min and the pressure was set at 20 mmHg.

The power supply 17 was turned on, the feed roller was turned, and the continuous carbon fiber bundle was moved toward the counter electrode 14 at a feed speed of about 10 mm / min. Discharge started after about 60 seconds, and a continuous carbon fiber bundle was continuously supplied at a feed speed of 5 to 20 mm / min while observing a change in the current value. The voltage value at the time of discharging was about 19 V and the current value was about 90 A, and the voltage value and the current value did not change during the discharging.

After discharging for about 10 hours,
The power supply 17 was turned off and left for 30 minutes to cool. The inside of the system was returned to the atmospheric pressure, and soot collected in the soot receiver 15 was collected. The amount of soot collected was 57 g, and the total weight of the continuous carbon fiber bundle that was electrodisintegrated was 137 g.
The soot was immersed in toluene to dissolve the fullerenes contained in the soot in toluene. The weight of the extracted fullerenes was 6.2 g, and the yield from the raw materials was 4.5%.

The characteristics of the continuous carbon fiber bundle of Example 2, the fluctuation range of current and voltage and the yield of fullerene when fullerene was produced using the same are shown in Table 1 below.

Comparative Example 1 For the continuous carbon fiber bundle of Comparative Example 1, Vesfite UM46-
12K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.4 g / m, tensile modulus: 43
Ton / mm ² , volume resistivity: 1.0 × 10 ⁻³ Ω · cm,
Single fiber diameter: 4.5 μm, d (002) = 3.42
Å)], and the carbon fiber strand 80 having a length of 20 m is used.
Books were bundled to form an inner layer. The outside of the inner layer made of the carbon fiber strand bundle is coated with Vesfite HM35-12K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.8 g / m, tensile modulus: 35 ton / m
m ² , volume resistivity: 1.0 × 10 ⁻³ Ω · cm, single fiber diameter: 6.7 μm, d (002) = 3.43 °)] and a single fiber is wound on the carbon fiber strand bundle at a winding pitch of 5 mm. From outside to form an outer layer so as to cover it tightly with a diameter of 7 mm
Thus, a continuous carbon fiber bundle of Comparative Example 1 having an apparent fiber density of about 1.0 g / cm ³ was produced. The material of the inner layer and the outer layer of Comparative Example 1 is the reverse of the material of the inner layer and the outer layer in the continuous carbon fiber bundle of Example 1.

Using the fullerene manufacturing apparatus shown in FIG. 3, an AC power supply was used as the power supply 17, and the current was set to 90 A and the voltage to 20 V. The continuous carbon fiber bundle of Comparative Example 1 was used as the carbonaceous raw material 12, and the continuous carbon fiber bundle was wound around a carbonaceous raw material supply device 11 (clear) in the processing chamber 16. And the gap between the end of the continuous carbon fiber bundle and the counter electrode 14 was set to 10 mm.

The power supply 17 is turned on under the same conditions (helium gas pressure and flow rate) as in the first embodiment, and the feed roller is turned to feed the continuous carbon fiber bundle toward the counter electrode 14 at a feed speed of about 10 mm / min. I moved it. Discharge started after about 60 seconds, and a continuous carbon fiber bundle was continuously supplied at a feed speed of 5 to 10 mm / min while observing a change in the current value. Although the voltage value at the time of discharge was 18 to 19 V and the current value was 88 to 90 A, the fluctuation range of the voltage was 12 to 30 V and the fluctuation range of the current was 70 to 100 A. Fluctuated greatly and was unstable.

After operating for about 5 hours to perform the discharge treatment, the power supply 17 was turned off and left for 30 minutes to cool. The inside of the system was returned to the atmospheric pressure, and soot collected in the soot receiver 15 was collected.
The amount of soot collected was 6.8 g. The total weight of the discharge-decomposed continuous carbon fiber bundle was 65 g. The collected soot was immersed in toluene to dissolve the fullerenes contained in the soot in toluene. The weight of the extracted fullerenes was 0.13 g, and the yield from the raw materials was 0.2%.

The characteristics of the continuous carbon fiber bundle of Comparative Example 1, the fluctuation range of the current and the voltage, and the yield of fullerene when fullerene was produced using the same are shown in Table 1 below.

Comparative Example 2 For the continuous carbon fiber bundle of Comparative Example 2, Vesfite HTA-1 was used as the material of the inner layer.
2K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.8 g / m, tensile elasticity: 24 tons / mm ² , volume resistivity: 1.5 × 10 ⁻³ Ω] Cm, single fiber diameter: 7.0 μm, d (002) = 3.45 °)]
, 23 carbon fiber strands having a length of 20 m were bundled to form an inner layer. The outside of the inner layer made of the carbon fiber strand bundle is made of Vesfite HTA-1 which is the same as the material of the inner layer.
An outer layer is formed such that one 2K carbon fiber strand is strongly wound from the outside of the bundle of carbon fiber strands at a winding pitch of 2 mm to cover the bundle, and the apparent fiber density is about 0.9.
A continuous carbon fiber bundle of Comparative Example 2 having a diameter of 5 mm was prepared at g / cm ³ .

Using the fullerene manufacturing apparatus shown in FIG. 3, an AC power supply was used as the power supply 17 and the current was set to 90 A and the voltage to 20 V. The continuous carbon fiber bundle of Comparative Example 2 was used as the carbonaceous raw material 12, and the continuous carbon fiber bundle was wound around the carbonaceous raw material supply device 11 (clear) in the processing chamber 16. And the gap between the end of the continuous carbon fiber bundle and the counter electrode 14 was set to 10 mm.

The power supply 17 is turned on under the same conditions (helium gas pressure and flow rate) as in the first embodiment, and the feed roller is turned to feed the continuous carbon fiber bundle to the counter electrode 14 at a feed speed of about 10 mm / min. I moved it. Discharge started after about 60 seconds, and a continuous carbon fiber bundle was continuously supplied at a feed speed of 10 to 25 mm / min while observing a change in the current value. Although the voltage value at the time of discharge was 20 to 22 V and the current value was 85 to 88 A, the voltage fluctuation range was 10 to 30 V and the current fluctuation range was 70 to 100 A. Fluctuated greatly and was unstable.

After operating for about 5 hours to perform the discharge treatment, the power supply 17 was turned off and left for 30 minutes to cool. The inside of the system was returned to the atmospheric pressure, and soot collected in the soot receiver 15 was collected.
The amount of soot collected was 7.5 g. The total weight of the discharge-decomposed continuous carbon fiber bundle was 80 g. The collected soot was immersed in toluene to dissolve the fullerenes contained in the soot in toluene. The weight of the extracted fullerenes was 0.11 g, and the yield from the raw materials was 0.1%.

Table 1 below summarizes the characteristics of the continuous carbon fiber bundle of Comparative Example 2, the fluctuation range of the current and the voltage, and the yield of fullerene when fullerene was produced using the same.

Example 3 For the continuous carbon fiber bundle of Example 3, Vesfite UM46 was used as the material of the inner layer.
-12K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.4 g / m, tensile modulus: 4
3 tons / mm ² , volume resistivity: 1.0 × 10 ⁻³ Ω · c
m, single fiber diameter: 4.5 μm, d (002) = 3.42
Å)] was used, and Vesfite HM was used as the core material.
35-12K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.8 g / m, tensile modulus: 35 ton / mm ² , volume resistivity: 1.0 × 10 ^{− 3} Ω
Cm, single fiber diameter: 6.7 μm, d (002) = 3.
43Å)], and 20 m consisting of the inner layer and the core
A total of 80 carbon fiber strands of a length were bundled.

The outside of the inner layer is provided by a trading card M50-6K.
[Product name: Carbon fiber strand manufactured by Toray Industries, Inc. (fiber weight: 0.36 g / m, tensile modulus: 50 ton / m
m ² , volume resistivity: 8.0 × 10 ⁻⁴ Ω · cm, d (00
2) = 3.41 °)] The outer layer is formed so as to cover the inner layer by strongly winding the inner layer made of the carbon fiber strand bundle from the outer layer at a winding pitch of 7 mm with one wire, and has a diameter of 7 mm.
In the third embodiment of the fiber density apparent is about 1.1 g / cm ³
Was produced.

Using the fullerene manufacturing apparatus shown in FIG. 3, an AC power supply was used as the power supply 17 and the current was set to 100 A and the voltage was set to 20 V. The continuous carbon fiber bundle of the third embodiment is used as the carbonaceous raw material 12, and the continuous carbon fiber bundle is wound around the carbonaceous raw material supply device 11 (clear) in the processing chamber 16. It was set apart so that the distance between the tip of the continuous carbon fiber bundle and the counter electrode 14 was 10 mm through the wire.

Next, the processing chamber 16 was closed, the system was evacuated by a vacuum pump, the pressure in the system was reduced to 1 × 10 ⁻² mmHg or less, and helium gas was introduced into the system. The helium gas flow rate was set to 500 ml / min and the pressure was set to 50 mmHg, balancing between the inflow of helium gas and the evacuation by the vacuum pump.

The power supply 17 was turned on, the feed roller was turned to start discharging, and a continuous carbon fiber bundle was continuously supplied at a feed speed of 5 to 10 mm / min. The current value at the time of discharge is approximately 98 A, and the apparent current density is approximately 500 A / cm.
^{Was 2} . During the discharge, the voltage value and the current value did not change.

Further, the counter electrode 14 was continuously rotated at an angular velocity of about 10 ° / min so that deposits accumulated on the counter electrode 14 were dispersed and accumulated.

After discharging for about 3 hours, the power supply 17 was turned off and left for 20 minutes to cool. The inside of the system was returned to the atmospheric pressure, and soot collected in the soot receiver 15 was collected.
The amount of soot collected was 36 g. The total weight of the discharge-decomposed continuous carbon fiber bundle was 80 g. The collected soot was immersed in toluene to dissolve the fullerenes contained in the soot in toluene. Extracted hula
The weight of the rens was 2.8 g, and the yield from the raw materials was 3.
5%.

The characteristics of the continuous carbon fiber bundle of Example 3, the fluctuation range of the current and voltage and the yield of fullerene when fullerene was produced using the same are shown in Table 1 below.

Comparative Example 3 For the continuous carbon fiber bundle of Comparative Example 3, Vesfite UM46-
12K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.4 g / m, tensile modulus: 43
Ton / mm ² , volume resistivity: 1.0 × 10 ⁻³ Ω · cm,
Single fiber diameter: 4.5 μm, d (002) = 3.42
Å)] and a 20 m long carbon fiber strand
This was bundled to form an inner layer. The outside of the inner layer made of the carbon fiber strand bundle is made of the same Vesfite UM as the material of the inner layer.
An outer layer is formed such that a single carbon fiber strand of 46-12K is wound around the outside of the bundle of carbon fiber strands at a winding pitch of 2 mm so as to be strongly wound and covered, and the apparent fiber density is about 1.1 g / cm ³ and the diameter is about 1.1 g / cm ³ . A 7 mm continuous carbon fiber bundle of Comparative Example 3 was produced.

Under the same fullerene production conditions as in Example 3, the power supply 17 was turned on and the feed roller was turned. About 6
Discharge starts after 0 seconds, and while watching the change in the current value, 5 to 2
The continuous carbon fiber bundle was continuously supplied at a feed speed of 0 mm / min. The current value at the time of discharge was 95 to 100 A, but the voltage fluctuation range was 14 to 28 V and the current fluctuation range was 7
5 to 95 A, and the fluctuation of the current and the voltage was large compared to the third embodiment, which was unstable.

After performing the discharge treatment by operating for about 3 hours, the power supply 17 was turned off and left for 20 minutes to cool. The inside of the system was returned to the atmospheric pressure, and soot collected in the soot receiver 15 was collected.
The amount of soot collected was 25 g. The total weight of the discharge-decomposed continuous carbon fiber bundle was 85 g. The collected soot was immersed in toluene to dissolve the fullerenes contained in the soot in toluene. Extracted hula
The weight of the rens was 0.56 g, and the yield from the raw materials was 0.7%.

Table 1 below summarizes the characteristics of the continuous carbon fiber bundle of Comparative Example 3, the fluctuation range of the current and voltage, and the yield of fullerene when fullerene was produced using the same.

[Example 4] For the continuous carbon fiber bundle of Example 4, Vesfite HM35-12 was used as a core material.
K [trade name: carbon fiber strand manufactured by Toho Rayon Co., Ltd. (fiber weight: 0.8 g / m, tensile modulus: 35 ton / mm ² , volume resistivity: 1.0 × 10 ⁻³ Ω] Cm, single fiber diameter: 6.7 μm, d (002) = 3.43 °)], and outside the core, Vesfite UM46-12K [trade name: as a material for the inner layer and the outer layer] Carbon fiber strand (fiber weight: Toho Rayon Co., Ltd.)
0.8 g / m, tensile modulus: 35 ton / mm ² , volume resistivity: 1.0 × 10 ⁻³ Ω · cm, single fiber diameter: 6.7
μm, d (002) = 3.43 °)], a total of 51 20 m-long carbon fiber strands comprising the inner layer and the core, the outer layer having a winding pitch of 2 mm, a diameter of 7 mm, and an apparent A continuous carbon fiber bundle of Example 4 having a fiber density of about 1.0 g / cm ³ was produced.

Using the fullerene manufacturing apparatus shown in FIG. 3, an AC power supply was used as the power supply 17 and the current was set to 90 A and the voltage was set to 20 V. The continuous carbon fiber bundle according to the fourth embodiment is used as the carbonaceous raw material 12, and the continuous carbon fiber bundle is wound around the carbonaceous raw material supply device 11 (clear) in the processing chamber 16. It was set apart so that the distance between the tip of the continuous carbon fiber bundle and the counter electrode 14 was 10 mm through the wire.

Then, operation was carried out for about 5 hours in the same manner as in Example 1 under the same helium pressure, helium gas flow rate, current and voltage conditions as in Example 1.

The amount of soot recovered in Example 4 was 3
It was 5 g. The total weight of the discharge-decomposed continuous carbon fiber bundle was 68 g. The collected soot was immersed in toluene to dissolve the fullerenes contained in the soot in toluene. The weight of the extracted fullerenes is 1.7 g.
And the yield from the raw materials was 2.5%.

Table 1 below summarizes the characteristics of the continuous carbon fiber bundle of Example 4 and the fluctuation range of the current and voltage and the yield of fullerene when fullerene is produced using the same.

Example 5 For the continuous carbon fiber bundle of Example 5, alumina fiber manufactured by Sumitomo Chemical Co., Ltd. (volume resistivity: 10 ⁷ Ω · cm or more, tensile modulus:
21 tons / mm ² , fiber weight: 0.5 g / m, fiber diameter: 17 μm). Outside the core, the inner layer and the outer layer are made of the same material as used in the second embodiment, and the diameter is 5 m in the same manner as in the second embodiment.
m, a continuous carbon fiber bundle of Example 5 having an apparent fiber density of 0.8 g / cm ³ was produced.

Using the fullerene producing apparatus shown in FIG. 3, fullerene was produced by operating the continuous carbon fiber bundle of Example 5 as a raw material under the same discharge conditions and operating conditions as in Example 2 for 10 hours.

The amount of soot recovered in Example 5 was 5
9 g. The total weight of the discharge-decomposed continuous carbon fiber bundle was 140 g. The collected soot was immersed in toluene to dissolve the fullerenes contained in the soot in toluene. The weight of the extracted fullerenes is 6.3.
g, and the yield from the raw material was 4.5%.

Table 1 below summarizes the characteristics of the continuous carbon fiber bundle of Example 5, the fluctuation range of the current and voltage, and the yield of fullerene when fullerene is produced using the same.

[0084]

[Table 1] According to Table 1, when fullerenes were produced by the arc discharge method using the continuous carbon fiber bundles of Examples 1 to 5,
Arc discharge is performed stably, and the yield of fullerene is high. On the other hand, when the continuous carbon fiber bundles of Comparative Examples 1 to 3 are used, fluctuations in voltage and current at the time of discharge occur, It can be seen that the yield of the compound was lower than that of Examples 1 to 5.

[0085]

According to the present invention, when fullerenes are produced using the continuous carbon fiber bundle for producing fullerenes by the arc discharge method of the present invention, the arc discharge is performed stably, and the yield of fullerenes is high.

The continuous carbon fiber bundle for producing fullerenes by the arc discharge method of the present invention is a long and flexible carbonaceous raw material. The size of the fullerene manufacturing apparatus can be made compact.

[Brief description of the drawings]

FIG. 1 shows a continuous carbon fiber bundle of the present invention (an example without a core).
FIG.

FIG. 2 shows a continuous carbon fiber bundle of the present invention (an example having a core).
FIG.

FIG. 3 is a schematic view of an apparatus for producing fullerene by arc discharge that can be used to produce fullerene using the continuous carbon fiber bundle of the present invention as a carbonaceous raw material.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 inner layer 2 outer layer 3 core 11 carbonaceous raw material supply device 12 carbonaceous raw material 13 transfer device 14 counter electrode 15 soot receiver 16 processing chamber 17 power supply 18 inert gas inlet 19 inert gas cylinder 20 exhaust port 21 vacuum pump

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C01B 31/00-31/36 B32B 5/14 D01F 9/08-9/32

Claims (9)

(57) [Claims] 1. A continuous carbon fiber bundle having a volume resistivity of 5 × 10 ⁻² Ω · cm or less and a diameter of 1 to 100 μm, which is manufactured by bundling single fibers of carbon fibers, and having a diameter of 3 mm or more, A continuous carbon fiber for producing fullerenes by an arc discharge method, wherein a tensile modulus of elasticity is higher in a radial direction from a center of the continuous carbon fiber bundle and a volume resistivity is substantially equal to or lower. Fiber bundle. 2. The continuous carbon fiber bundle is an aggregate of carbon fiber strands in which 100 to 100,000 single carbon fibers are bundled, and the carbon fiber strand has a tensile elasticity of 35 tons / mm ^2. The continuous carbon fiber bundle for producing fullerenes by an arc discharge method according to claim 1, wherein the spacing between the (002) planes of graphite obtained by wide-angle X-ray diffraction is 3.45 ° or less. 3. The continuous carbon fiber bundle comprises an inner layer made of carbon fibers inside, and an outer layer made of carbon fibers covering the outside of the inner layer, wherein the tensile modulus of the outer layer is higher than that of the inner layer. 3. A continuous carbon fiber bundle for producing fullerenes by an arc discharge method according to claim 1 or 2, wherein the outer layer has a volume resistivity substantially equal to or lower than that of the inner layer. . 4. The continuous carbon fiber bundle comprises a core made of carbon fiber at the center, an inner layer made of carbon fibers covering the outside of the core, and a carbon fiber covering the outside of the inner layer. Wherein the tensile modulus of the inner layer is higher than that of the core, and the volume resistivity of the inner layer is substantially equal to or lower than that of the core, and the tensile elastic modulus of the outer layer is higher than that of the inner layer. 3. The continuous carbon fiber bundle for producing fullerene by an arc discharge method according to claim 1, wherein the outer layer has a high volume resistivity and the volume resistivity of the outer layer is substantially equal to or lower than that of the inner layer. 5. A core composed of fibers selected from inorganic fibers and organic fibers other than carbon fibers, and (2) a volume resistivity covering the outside of the core of 5 × 10 ⁻² Ω ·
(3) Volume resistivity covering the outside of the inner layer, 5 × 10 ⁻² Ω.
A continuous carbon fiber bundle having a diameter of 3 mm or more, comprising an outer layer made of a single fiber carbon fiber having a diameter of 1 to 100 μm or less, wherein the tensile modulus of the inner layer is higher than that of the core, and The volume resistivity of the inner layer is substantially equal to or lower than that of the core, and the tensile elasticity of the outer layer is higher than that of the inner layer, and the volume resistivity of the outer layer is substantially equal to or larger than that of the inner layer. A continuous carbon fiber bundle for producing fullerenes by an arc discharge method. 6. The inner layer is composed of 100 single fibers of carbon fiber.
An aggregate of carbon fiber strands of about 100,000 bundles, the tensile modulus of the carbon fiber strands being 35 tons / mm ² or more, and the (002) plane of graphite obtained by wide-angle X-ray diffraction. The continuous carbon fiber bundle for producing fullerenes by an arc discharge method according to claim 5, wherein the interval is 3.45 ° or less. 7. The fullerene production according to claim 3, wherein the outer layer is formed by continuously winding a carbon fiber in a spiral shape. For continuous carbon fiber bundles. 8. The continuous carbon fiber bundle, or the inner layer and / or the outer layer, is formed of a braid, a woven fabric, a twisted yarn, a combined yarn of carbon fibers, or a combination thereof. A continuous carbon fiber bundle for producing fullerenes by an arc discharge method according to 1, 2, 3, 4, 5, 6, or 7. 9. The continuous carbon fiber bundle has an apparent fiber bundle density of 0.5 g / cm ³ or more.
4. A continuous carbon fiber bundle for producing fullerenes by an arc discharge method according to 4, 5, 6, 7 or 8.