JP2015067483A - Manufacturing method of fibrous carbon material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of fibrous carbon material, capable of efficiently collecting the fibrous carbon material without damaging the fibrous carbon material.SOLUTION: The manufacturing method of fibrous carbon material includes: a step (1) of growing a fibrous carbon material 2 using a catalyst attached to the surface of a substrate 1 as nucleous; a step (2) of embedding an edge of the fibrous carbon material on the opposite side of the substrate 1 and impurities 3 derived from the catalyst attached to the edge into a softened transfer film 4, and then curing the transfer film 4; a step (3) of transferring the fibrous carbon material 2 from the substrate 1 to the transfer film 4 after the step (2); and a step (4) of cutting the vicinity of the base part in a portion of the fibrous carbon material 2 transferred to the transfer film 4, which is exposed from the transfer film 4, with cutting means.

Description

  The present invention relates to a method for producing a fibrous carbon material.

  Conventionally, a method of growing a fibrous carbon material such as a carbon nanotube using a chemical vapor deposition method (CVD method) with a catalyst attached to the surface of a substrate as a nucleus is known (for example, Patent Document 1). ). In the CVD method, a fibrous carbon material can be grown on a substrate by bringing a carbon-containing gas (CVD gas) into contact with a catalyst containing a metal such as iron or nickel in a high temperature environment.

As a method for recovering the fibrous carbon material obtained on the substrate, for example, the fibrous carbon material 32 generated on the substrate 31 shown in FIG. 5A is obtained as shown in FIG. It is conceivable to peel off the substrate 31 using the spatula 35.
Moreover, in patent document 2, as shown to (b) of FIG. 6, high temperature water 36 is injected into the fibrous carbon material 32 produced | generated on the board | substrate 31 shown to (a) of FIG. It has been proposed to peel the carbon material 32 from the substrate 31.

However, impurities 33 (metal oxide or the like) derived from the catalyst adhere to the substrate 31 and the fibrous carbon material 2. Impurity 33 derived from the catalyst adheres to the surface of the substrate 31 and the end of the fibrous carbon material 32 on the substrate 31 side, and contributes to the growth at the base of the fibrous carbon material 32. The fibrous carbon material adheres to the surface of 31 and impurities 33b derived from the catalyst that has not contributed to the growth of the fibrous carbon material 32, and the end of the fibrous carbon material 32 opposite to the substrate 31. And impurities 33c derived from the catalyst that contributed to the growth at the tip of 32.
Therefore, in the collection method shown in FIGS. 5 and 6 above, the catalyst-derived impurities 33 are also collected at the same time as the fibrous carbon material 32, so that the collection rate of the fibrous carbon material 32 is lowered.

  As a method for suppressing a decrease in the recovery rate of the fibrous carbon material due to the inclusion of impurities, as described in Non-Patent Document 1, removing impurities derived from the catalyst from the fibrous carbon material using a strong acid. Conceivable.

Japanese Patent No. 3985029 JP 2011-84446 A

J.G.Wiltshire et al., Chem. Phys. Lett. 386, 239-243 (2004)

  However, the method described in Non-Patent Document 1 has a problem in that the fibrous carbon material itself is damaged because the fibrous carbon material comes into contact with a chemical having strong oxidizing power.

  Then, an object of this invention is to provide the manufacturing method of the fibrous carbon material which can collect | recover a fibrous carbon material efficiently, without damaging a fibrous carbon material.

The present invention is as follows.
[1] (1) A step of growing a fibrous carbon material with a catalyst attached to the surface of the substrate as a nucleus;
(2) a step of curing the transfer film after embedding the end portion of the fibrous carbon material opposite to the substrate side and the catalyst-derived impurities attached to the end portion in the softened transfer film;
(3) after the step (2), transferring the fibrous carbon material from the substrate to a transfer film and separating the substrate and impurities derived from the catalyst attached to the surface of the substrate;
(4) The vicinity of the base in the portion exposed from the transfer film in the fibrous carbon material transferred to the transfer film is cut using a cutting means, and most of the fibrous carbon material is transferred to the transfer film in the fibrous carbon material. Separating and recovering from the transfer film embedded with the catalyst-derived impurities attached to the edge and the edge;
The manufacturing method of the fibrous carbon material characterized by including.

[2] The transfer film is a resin film having a thickness of 10 to 1000 μm,
The method for producing a fibrous carbon material according to [1], wherein the resin film is made of a thermoplastic resin or a thermosetting resin.
[3] The method for producing a fibrous carbon material according to [2], wherein the thermoplastic resin is at least one selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyimide, and polyvinylidene fluoride.
[4] The method for producing a fibrous carbon material according to [2], wherein the thermosetting resin is an epoxy resin.
[5] The method for producing a fibrous carbon material according to any one of [1] to [4], wherein the cutting means is a laser or a blade.

[6] The fiber according to any one of [1] to [5], wherein the fibrous carbon material is grown in step (1) by reusing the substrate separated in step (3). Method for producing a carbonaceous material.
[7] The average length of the fibrous carbon material grown on one surface of the substrate in the step (1) is 10 to 1000 μm, as described in any one of [1] to [6] Manufacturing method of fibrous carbon material.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the fibrous carbon material which can collect | recover a fibrous carbon material efficiently can be provided, without damaging a fibrous carbon material.

(A)-(e) is a schematic longitudinal cross-sectional view which shows an example of the manufacturing method of the fibrous carbon material of this invention, (a) is the state of process (1), (b) is process (2). The state, (c) shows the state in step (3), (d) shows the state in step (4), and (e) shows the state in which the fibrous carbon material cut in step (4) has been recovered. It is a schematic longitudinal cross-sectional view which shows another example of the process (4) in the manufacturing method of FIG. It is a schematic longitudinal cross-sectional view which shows an example of the method of manufacturing the fibrous carbon material of this invention continuously. It is a schematic longitudinal cross-sectional view which shows another example of the method of manufacturing the fibrous carbon material of this invention continuously. (A), (b) is a schematic longitudinal cross-sectional view which shows the collection process of the fibrous carbon material in the manufacturing method of the conventional fibrous carbon material, (a) is fibrous carbon on the surface of the board | substrate which carried the catalyst. A state where the material is generated is shown, and (b) shows a state where the fibrous carbon material is peeled off from the substrate using a spatula. (A), (b) is a schematic longitudinal cross-sectional view which shows the collection | recovery process of the fibrous carbon material in the other conventional manufacturing method of fibrous carbon material, (a) is a fiber on the surface of the board | substrate which supported the catalyst. (B) shows a state in which the fibrous carbon material is peeled from the substrate by jetting water.

The present invention relates to a method for producing a fibrous carbon material, and includes the following steps (1) to (4).
Step (1): A fibrous carbon material is grown using the catalyst attached to the surface of the substrate as a nucleus.
Step (2): After embedding the end portion of the fibrous carbon material opposite to the substrate side and the catalyst-derived impurities attached to the end portion in the softened transfer film, the transfer film is cured.
Step (3): After the step (2), the fibrous carbon material is transferred from the substrate to the transfer film, and separated from the substrate and the catalyst-derived impurities attached to the surface of the substrate.
Step (4): The vicinity of the base in the portion of the fibrous carbon material transferred to the transfer film that is exposed from the transfer film is cut using a cutting means, so that most of the fibrous carbon material is in the fibrous carbon material. The transfer film is separated from the transfer film side end and the transfer film embedded with the catalyst-derived impurities attached to the end and collected.

In the present invention, the fibrous carbon material can be separated and recovered from impurities adhering to the substrate. Further, the fibrous carbon material can be separated and recovered from impurities attached to the tip of the fibrous carbon material. For this reason, the recovery rate of the fibrous carbon material can be increased.
In the present invention, since impurities can be separated without using a strong oxidizing agent, the fibrous carbon material does not come into contact with the strong oxidizing agent and damage the side walls of the fibrous carbon material.

Examples of the fibrous carbon material include carbon nanotube (CNT), carbon nanofiber, carbon nanocoil, carbon nanowall, and carbon nanohorn.
For example, CNT has electrical properties that change depending on how the graphene sheet is wound, high thermal conductivity, and mechanical strength, and is expected to be used in various ways. For example, it is used for the probe of a reinforced plastic or a scanning probe microscope by taking advantage of high mechanical strength. Utilizing excellent electrical characteristics, it is used as a field emission source for field emission displays. Utilizing the size of the surface area, it is used for gas absorbers, fuel cell electrode catalysts, and capacitor electrodes.

[Step (1)]
For the production of the fibrous carbon material, a chemical vapor deposition method (CVD method) is used. By supplying the reaction gas to the substrate carrying the catalyst in a high temperature environment, a fibrous carbon material grows with the catalyst as a nucleus. At this time, with the catalyst attached to the end of the fibrous carbon material opposite to the substrate side, the fibrous carbon material grows from the end of the fibrous carbon material opposite to the substrate side, or the fibrous carbon material The fibrous carbon material may grow from the end of the fibrous carbon material on the substrate side in a state where the catalyst is attached to the end of the material on the substrate side.
The fibrous carbon material grows so as to extend in a substantially vertical direction from the substrate. A fibrous carbon material oriented in a substantially vertical direction from the substrate is formed densely, so that a layer of the fibrous carbon material is formed on the surface of the substrate.

As a method for producing the fibrous carbon material, in addition to the method using the substrate carrying the catalyst in the present invention, the catalyst particles are filled in the fluidized bed type reaction vessel, and the catalyst particles are flowed to the surface of the catalyst particles. A technique for generating a fibrous carbon material is mentioned.
However, in the method using the fluidized bed reaction vessel, the catalyst particles to which the fibrous carbon material in the growing process collides with each other, or the catalyst particles collide with the inner wall of the reaction vessel. Material growth may be suppressed. Further, since the CNT is synthesized while the catalyst passes through the fluidized bed type reaction vessel, the reaction time is short. Therefore, the obtained fibrous carbon material has a short length. In addition, there is a problem that the recovered fibrous carbon material contains a large amount of impurities derived from the catalyst.
On the other hand, in the method of the present invention in which the fibrous carbon material is grown on the substrate to which the catalyst is attached, it is possible to generate a fibrous carbon material that is as long as about 50 to 1000 μm.

  A known substrate may be used as the substrate. For example, silicon, stainless steel, or quartz glass is used as the material of the substrate. The thickness of the substrate is, for example, 50 to 1000 μm.

  A known catalyst may be used as the catalyst. A catalyst contains metals, such as iron and nickel, for example. A known method may be used as a catalyst loading method. A layered catalyst (for example, a thickness of 0.5 to 5 nm) may be supported on the surface of the substrate, or a particulate catalyst (for example, an average particle diameter (D50) of 1 to 50 nm) may be supported on the surface of the substrate. Good.

Here, FIG. 1A shows an example of the state of the step (1).
A fibrous carbon material 2 is formed on the surface of the substrate 1. After the fibrous carbon material 2 is generated by the CVD method, impurities 3 derived from the catalyst are attached to the substrate 1 and the fibrous carbon material 2. Impurity 3 derived from the catalyst adheres to the surface of the substrate 1 and the end of the fibrous carbon material 2 on the substrate 1 side, and contributes to the growth at the base of the fibrous carbon material 2, and the impurity 3a derived from the catalyst, Impurities 3b derived from a catalyst that has adhered to the surface of the substrate 1 and did not contribute to the growth of the fibrous carbon material 2, and adhered to the end of the fibrous carbon material 2 opposite to the substrate 1 side. And impurities 3 c derived from the catalyst that contributed to the growth at the tip of the material 2.

[Step (2)]
In step (2), for example, a predetermined pressure is applied to the laminate obtained by superimposing the softened transfer film on the substrate on which the fibrous carbon material is generated, so that a part of the fibrous carbon material is obtained. Embedded in the transfer film. After embedding a part of the fibrous carbon material in the transfer film, the transfer film is cured. The softened state here includes a melted state.

  Reliability for transfer from substrate to transfer film in step (3), recovery rate of fibrous carbon material in step (4) (fiber length of recovered fibrous carbon material), fibrous carbon in step (4) From the viewpoint of the reliability of separation of the material from impurities and the reuse of the transfer film separated from the majority of the fibrous carbon material in step (4), the end of the fibrous carbon material opposite to the substrate side, The impurities adhering to the end are preferably embedded in a region from the outermost surface of the transfer film to a depth of about 1 to 10 μm.

The viscosity of the softened transfer film is preferably 0.1 to 5 Pa · s. As for the pressure added to said laminated body, 1-2 kg / cm < ² > is preferable. If it is the range of the said viscosity and pressure, the edge part of fibrous carbon material and the impurity adhering to the said edge part are embedded in the appropriate area | region from the outermost surface of the transfer film mentioned above to the depth of about 1-10 micrometers. Can do.

  Examples of the method for adjusting the softness of the transfer film include a method of changing the temperature of the transfer film and utilizing a chemical reaction (for example, a polymerization reaction or a crosslinking reaction) of a compound contained in the transfer film.

  From the viewpoint of reliability with respect to transfer from the substrate to the transfer film in the step (3), the thickness of the transfer film is preferably 10 to 1000 μm.

For example, a resin film is used as the transfer film.
Examples of the material of the resin film include a thermoplastic resin or a thermosetting resin.
Examples of the thermoplastic resin include polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyimide (PI), and polyvinylidene fluoride (PVDF).
In the case of a thermoplastic resin, a part of the fibrous carbon material is embedded in a resin film heated to a predetermined temperature and softened or melted, and then cured by cooling the resin film to a predetermined temperature. .
Examples of the thermosetting resin include an epoxy resin. In the case of a thermosetting resin, after a part of the fibrous carbon material is embedded in the resin film, the resin film can be heated to a predetermined temperature to advance the curing reaction.

Since it is easy to control embedding within an appropriate region from the outermost surface of the transfer film described above to a depth of about 10 to 1000 μm, the transfer film is a resin film having a thickness of 10 to 1000 μm. It is preferably a thermoplastic resin such as polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyimide (PI), polyvinylidene fluoride (PVDF), or a thermosetting resin.
Furthermore, the heating temperature of the resin film for softening the resin film is preferably equal to or higher than the softening temperature of the thermoplastic resin.
Moreover, since it is easy to control embedding within an appropriate region from the outermost surface of the resin film to a depth of about 10 to 1000 μm, when the material of the resin film is PE, the heating temperature of the PE film is 100 to 150 ° C. Preferably, when the material of the resin film is PP, the heating temperature of the PP film is preferably 130 to 160 ° C.

Moreover, you may use the laminated | multilayer film which consists of a resin layer or the rubber layer formed in the one surface of a metal plate and a metal plate for a transfer film. The metal plate is used for the purpose of supporting the resin layer or the rubber layer. Part of the fibrous carbon material and impurities are embedded in the resin layer or rubber layer.
The resin layer or rubber layer is formed, for example, by applying a solution containing resin or rubber to one surface of a metal plate and then drying it.

As resin used for a resin layer, the same material as said resin film is used. Among these, PE, PC, and PP are preferable as the resin used for the resin layer because of excellent transferability to CNT.
As the rubber, for example, silicon rubber, butadiene, or fluorine rubber is used. Among these, silicon rubber is preferable because of its excellent affinity with CNT.

  The strength of the transfer layer is obtained, and the flexibility of a degree that can be applied to an apparatus that continuously performs the manufacturing process of the present invention is obtained. Therefore, the thickness of the resin layer or the rubber layer is preferably 10 to 1000 μm. .

As the metal used for the metal plate, Al, Cu, Ag, or Au is used.
Among these, since it is inexpensive, the metal used for the metal plate is preferably Al or Cu.

  The thickness of the metal plate is preferably 10 to 1000 μm because strength for transfer can be obtained and flexibility that can be applied to an apparatus that continuously performs the manufacturing process of the present invention can be obtained.

  The layer of the fibrous carbon material is formed of a large number of fibrous carbons having a very fine structure of nano size on the surface of the substrate. Many fibrous carbons are oriented in a direction substantially perpendicular to the surface of the substrate. For this reason, softened resin or rubber does not penetrate deeply between the adjacent fibrous carbon materials, and the state where the resin film or laminated film is placed on the upper surface of the fibrous carbon material layer is maintained. The

Here, FIG. 1B shows an example of the state of the step (2).
The end portion of the fibrous carbon material 2 opposite to the substrate 1 side and the catalyst-derived impurities 3 c attached to the end portion are embedded in the transfer film 4.

[Step (3)]
In the step (3), since a part of the fibrous carbon material is embedded in the transfer film, the fibrous carbon material is fixed to the transfer film side when the transfer film is pulled away from the substrate. The end on the substrate side is separated from the substrate. At this time, impurities adhering to the surface of the substrate (including impurities derived from the catalyst that contributed to the growth of the fibrous carbon material) originate from the catalyst supported on the substrate, and thus remain on the surface of the substrate.

  The height of the free end portion (the end portion opposite to the substrate side) of the fibrous carbon material generated on the surface of the substrate varies slightly, but the surface of the substrate is extremely smooth. Therefore, after transferring the fibrous carbon material from the substrate to the transfer film, the height of the fibrous carbon material in the portion exposed from the transfer film is substantially constant. That is, the upper surface of the fibrous carbon material layer formed by densely gathering a number of fibrous carbon materials oriented in a direction substantially perpendicular to the surface of the transfer film covering the surface of the transfer film (the side opposite to the transfer film side) The surface formed by the gathering of the end portions of the surfaces is smooth.

Here, FIG. 1C shows an example of the state of the step (3).
The fibrous carbon material 2 generated on the surface of the substrate 1 is transferred to the transfer film 4. By this transfer, the fibrous carbon material 2 is separated from the substrate 1 and the impurities 3a and 3b derived from the catalyst attached to the substrate 1.
The substrate 1 separated from the fibrous carbon material 2 in the step (3) can be reused as it is as a substrate carrying a catalyst for producing the fibrous carbon material 2. Alternatively, the impurities 3a and 3b adhering to the substrate 1 may be removed using a chemical or the like having a strong oxidizing power, and then reused as a substrate before supporting the catalyst.

[Step (4)]
In the step (4), impurities are removed from the fibrous carbon material by physically cutting a predetermined portion of the fibrous carbon material without using a chemical having strong oxidizing power. For this reason, the fibrous carbon material can be efficiently recovered while maintaining the crystallinity and properties of the fibrous carbon material without damaging the original characteristics of the fibrous carbon material.

  As a cutting means for cutting the fibrous carbon material transferred to the resin film, it is preferable to use a blade, a razor blade, a glass knife having a sharp edge.

In addition, it is preferable to use a laser as the cutting means because the fibrous carbon material can be recovered with higher accuracy and can be recovered by microfabrication. By heating and burning off a portion of the fibrous carbon material at a certain distance from the base of the transfer film by irradiating with a laser, variation in fiber length of the fibrous carbon material can be greatly reduced. Examples of the type of laser include a neutral particle laser, a He—Ne laser, and a femtosecond laser. For example, a femtosecond laser having a pulse width of 100 fs may be continuously irradiated.
The laser irradiation apparatus used for laser irradiation preferably includes a minute position control mechanism capable of controlling the laser irradiation position in the X-axis, Y-axis, and Z-axis directions. As shown in FIG. 2, the distance from the transfer film 4 of the fibrous carbon material 2 irradiated with the laser 5 can be controlled to be constant, and the cut surface of the layer of the fibrous carbon material 2 can be smoothed. . When viewed from the cross section along the thickness direction of the transfer film 4, the fibrous carbon material 2 can be linearly cut in the direction of the arrow in the diagram on the left side in FIG. 2.

  Alternatively, the fibrous carbon material may be cut by high-pressure injection of an inert gas (for example, nitrogen gas, argon gas, helium gas), water (for example, ion exchange water) or alcohol to a predetermined portion of the fibrous carbon material. Good.

Here, (d) of FIG. 1 shows an example of the state of a process (4). (E) of FIG. 1 shows the fibrous carbon material 2 recovered in the step (4).
The vicinity of the base portion of the fibrous carbon material 2 exposed from the transfer film 4 is cut by the blade 6.
Thereby, most of the fibrous carbon material 2 is separated from the transfer film 4 side end portion in the fibrous carbon material 2 and the transfer film 4 embedded with the catalyst-derived impurities 3c attached to the end portion, Collected.
As shown to (e) of FIG. 1, the collect | recovered fibrous carbon material 2 does not contain the impurities 3a-3c.

  As a method for collecting the fibrous carbon material 2, for example, a method of sucking and collecting the fibrous carbon material 2 so that the fibrous carbon material 2 does not scatter when the fibrous carbon material 2 is collected, A method of recovering the fibrous carbon material 2 by using it is mentioned.

  The transfer film 4 separated from the fibrous carbon material 2 in the step (4) can be reused as it is for transferring the fibrous carbon material 2 produced in the step (1) from the substrate 1. The transfer film should just have the role which hold | maintains the fibrous carbon material 2 through a process, and even if a certain amount of impurities adheres, it does not have a bad influence on the fibrous carbon material 2. If the amount of impurities adhering to the transfer film increases, the edge of the fibrous carbon material 2 embedded in the transfer film 4 and the impurities 3c can be removed from the transfer film 4 using a chemical or the like having a strong oxidizing power. That's fine. Any material embedded in a region from the outermost surface of the transfer film 4 to a depth of about 1 to 10 μm can be easily removed using a chemical or the like having strong oxidizing power.

Examples of the present invention will be described in detail below, but the present invention is not limited to the examples.
Example 1
[Step (1)]
A catalyst thin film (thickness 2 μm) was formed on the surface of a Si substrate (thickness 1000 μm) by sputtering to obtain a substrate carrying the catalyst. As the catalyst, a metal catalyst containing Fe as a main component and Ni and Co in addition to Fe was used. The molar ratio of various metals in the catalyst was Ni: Fe: Co = 1: 4: 1.
After setting the substrate carrying the catalyst in a predetermined electric furnace, the electric furnace was held at 700 ° C. for 10 minutes in a hydrogen atmosphere. Thereafter, acetylene gas was supplied as CVD gas (carbon source) into the electric furnace, and the inside of the electric furnace was heated to 700 ° C. to grow CNTs on the surface of the substrate (thin film). The CNTs formed on the surface of the substrate had an average fiber length of about 100 μm and a bulk density of about 15 mg / cm ³ .

[Step (2)]
A load of 1 kg / cm ² was applied to the laminate obtained by overlaying a PE film (thickness 50 μm) on the CNT layer formed on the surface of the substrate. At this time, the laminate was heated at 200 ° C. for 10 minutes. Thereafter, the laminate was cooled to room temperature.

[Step (3)]
CNTs were transferred from the substrate to the PE film.

[Step (4)]
The vicinity of the CNT base was irradiated with a laser to separate most of the CNT from the PE film and collect it. At this time, the laser was irradiated to the position of about 20 μm in height from the surface of the PE film in CNT.

<< Comparative Example 1 >>
In the same manner as in Example 1, CNTs were grown on the surface of the substrate carrying the catalyst ((a) of FIG. 6). Thereafter, as shown in FIG. 6B, ion-exchanged water was sprayed onto the substrate to separate and dry the CNTs from the substrate. In this way, CNTs were collected.

<< Comparative Example 2 >>
In Comparative Example 1, the CNT separated from the substrate (containing catalyst-derived impurities) was added into a mixed acid (sulfuric acid: nitric acid = 3: 1) and stirred for 10 minutes. Thereafter, the CNTs were washed with water and dried. In this way, CNTs were collected.

The CNTs collected in Example 1 and Comparative Examples 1 and 2 were evaluated as follows.
(1) Measurement of amount of impurities contained in CNT Using impurity energy dispersive X-ray analysis (EDX), the amount of impurities derived from the catalyst contained in the collected CNTs was determined as the Fe concentration.

(2) Evaluation of damage on the CNT surface Using Raman spectroscopy, the presence or absence of damage on the CNT surface was examined. Specifically, in the Raman spectrum of CNT, a G-band peak derived from a graphite structure appears in the vicinity of 1590 cm ⁻¹ , and a defect-derived D band peak appears in the vicinity of 1350 cm ⁻¹ . The degree of damage on the CNT surface was evaluated using the ratio of the peak of the G band to the peak of the D band (hereinafter referred to as G / D ratio). In addition, it shows that the degree of the defect of CNT is so small that G / D ratio is large.

As a result, in Example 1, the Fe content in the recovered CNT was 0.1% by weight, and the amount of impurities contained in the recovered CNT was greatly reduced. On the other hand, in Comparative Example 1, the Fe content in the recovered CNT was 1% by weight, and many impurities were contained in the recovered CNT.
In Example 1, the recovered CNT had a G / D ratio of about 1, and there was almost no damage on the CNT surface (side surface), whereas in Comparative Example 2, the recovered CNT G / D The D ratio was about 0.6, and it was found that much damage on the CNT surface (side surface) occurred.

Example 2
In this example, a method of manufacturing CNTs by continuously performing the steps of Example 1 using the manufacturing apparatus shown in FIG. The manufacturing apparatus shown in FIG. 3 includes a CNT generation unit 21, a CNT transfer unit 22, and a CNT collection unit 23.

In the CNT generating unit 21, a step (1) of growing CNTs on the surface of the substrate carrying the catalyst is performed.
In the CNT transfer section 22, a step of curing the resin film 14 after embedding the end of the CNT 12 opposite to the substrate 11 and the catalyst-derived impurities attached to the end in the softened resin film 14 (2 And after the step (2), the CNT 12 is transferred from the substrate 11 to the resin film 14 and separated from the substrate 11 and catalyst-derived impurities attached to the surface of the substrate 11. Is done.

  In the CNT collection part 23, the vicinity of the base part in the part exposed from the resin film 14 in the CNT 12 transferred to the resin film 14 is cut, and the most part of the CNT 12 is divided into the end part on the resin film 14 side in the CNT 12 and the end part. A step (4) of separating and recovering from the resin film 14 embedded with catalyst-derived impurities attached to the substrate is performed.

The manufacturing apparatus supplies a supply roller 14 a for supplying the substrate 1 carrying the catalyst in the CNT generating unit 11, a heater (not shown) for heating the CNT generating unit 11, and a reactive gas in the CNT generating unit 11. And a reactive gas supply unit 7.
The manufacturing apparatus also includes a vacuum pump (not shown) for discharging the gas in the generation unit 11.

The manufacturing apparatus includes a supply roller 15a for supplying the resin film 14 on the CNT 12 layer formed on the surface of the substrate 11, the substrate 11 on which the CNT 12 layer is formed, and the softened resin film 14. A pair of rollers 8 for passing the stacked laminate and applying a predetermined pressure to the laminate, and a recovery roller 14b for peeling the substrate 11 from the laminate and winding the substrate 11 are provided. . The recovered substrate 11 can be reused for the generation of the CNTs 12.
By applying pressure to the laminated body by the pair of rollers 8, the end of the CNT 12 generated by the generation unit 21 on the side opposite to the substrate 11 side and the catalyst-derived impurities attached to the end are added to the resin film 14. Embedded.

  The manufacturing apparatus includes a heater (not shown) for softening the resin film 14 immediately before the substrate 11 having the CNT 12 layer formed on the surface is overlapped with the resin film 14, and a laminate that includes a plurality of rollers 8. A cooling device (not shown) for cooling and curing the resin film 14 in the latter half of the passage is provided.

The manufacturing apparatus includes a laser irradiation device 9 that cuts the vicinity of the base portion in the portion of the CNT 12 transferred to the resin film 14 that is exposed from the resin film 14.
By the laser irradiation of the laser irradiation device 9, most of the CNTs 12 are separated from the resin film 14 in which the resin film 14 side end of the CNT 12 and the catalyst-derived impurities attached to the end are embedded. A roller 18 is provided at a position where the laser 5 is irradiated so that the laser 5 can be easily irradiated from the side surface of the CNT 12.

  The laser irradiation device 9 includes a minute position control mechanism for accurately controlling the laser position in the X-axis, Y-axis, and Z-axis directions. The length of the CNT 12 collected by the position control of this mechanism can be adjusted, and variations in the length can be reduced. Thereby, it is not necessary to adjust the length of the CNT 12 or adjust the variation in the length of the CNT 12 when generating the CNT.

The manufacturing apparatus includes an end portion on the resin film 14 side of the CNT 12 and a collection roller 15b for winding up the resin film 14 in which impurities derived from the catalyst attached to the end portion are embedded. The collected resin film 14 can be reused to transfer the CNTs 12 generated by the generation unit 21 from the substrate 11.
The manufacturing apparatus includes a suction device 20 for sucking and collecting most of the CNTs 12 cut by laser irradiation. By sucking and collecting the CNTs 12 with the suction device 20, it is possible to prevent a reduction in the recovery rate of the CNTs 12 due to scattering of the CNTs 12 when the CNTs 12 are collected.

CNT12 was manufactured on the conditions shown below using said manufacturing apparatus.
A long stainless steel foil (thickness 50 μm, width 300 mm) was used for the substrate 11. Fe was used as a catalyst. The heating temperature by the heater in the CNT generation unit 21 was set to 700 ° C. An acetylene gas was used as the reaction gas supplied from the reaction gas supply unit 7 into the CNT generation unit 21. The pressure applied to the laminate by the pair of rollers 8 was 1 kg / cm ² . A long PE film (thickness 50 μm, width 300 mm) was used for the resin film 14. In the transfer part 22, the resin film 14 was heated to 200 ° C. with a heater and softened. In the transfer part 22, the resin film 14 was cooled to room temperature with a cooling device and cured. In the collection part 23, the irradiation position of the laser 5 was fixed so that the laser 5 was irradiated to a portion of the CNT 12 having a height of about 20 μm from the surface of the resin film 14.

Evaluation similar to Example 1 was performed about obtained CNT12.
As a result, the Fe content in the CNT 12 recovered in Example 2 was 0.1% by weight, and the amount of impurities contained in the recovered CNT 12 was greatly reduced. The recovered CNT12 had a G / D ratio of about 1, and there was no damage on the surface (side surface) of the CNT12 as in Comparative Example 2.
In the present embodiment, the manufacturing apparatus shown in FIG. 3 is used for manufacturing CNTs, but can be used as a manufacturing apparatus for fibrous carbon materials other than CNTs.

Example 3
In this example, a method of manufacturing CNTs by continuously performing the steps of Example 1 using the manufacturing apparatus shown in FIG. The manufacturing apparatus shown in FIG. 4 includes a CNT generation unit 24, a CNT transfer unit 25, and a CNT collection unit 26. The CNT generation unit 24 has the same configuration as the CNT generation unit 21 of FIG. The CNT transfer unit 25 has the same configuration as the CNT transfer unit 22 of FIG. 3 except that it includes a molten resin supply unit 19 that supplies the molten resin 16 instead of the supply roller 15a that supplies the softened resin film 14. The CNT collection unit 26 has the same configuration as the CNT collection unit 23 in FIG. 3 except that the blade 6 is provided instead of the laser irradiation device 9.

Using the manufacturing apparatus shown in FIG. 4, CNTs were manufactured under the conditions shown below.
A long stainless steel foil (thickness 50 μm, width 300 mm) was used for the substrate 21. Fe was used as a catalyst. The heating temperature by the heater in the CNT generation unit 24 was set to 700 ° C. Acetylene gas was used as the reaction gas supplied from the reaction gas supply unit 7 into the CNT generation unit 11. The pressure applied to the laminate by the pair of rollers 8 was 1 kg / cm ² . As the molten resin 16, molten PE (temperature of 200 ° C.) was used, and the coating amount of the molten resin 16 to be supplied was adjusted so that the thickness of the layer of the molten resin applied on the substrate 1 was 0.5 mm. In the transfer unit 25, the molten resin 16 was cooled to room temperature with a cooling device and cured to obtain a resin film 14. In the collection unit 26, the blade 6 was fixed so that the blade edge of the blade 6 hits the position of about 20 μm in height from the surface of the resin film 14 in the CNT 12.

Evaluation similar to Example 1 was performed about obtained CNT12.
As a result, the Fe content in the CNT 12 recovered in Example 3 was 0.1% by weight, and the amount of impurities contained in the recovered CNT 12 was greatly reduced. The recovered CNT12 had a G / D ratio of about 1, and there was no damage on the surface (side surface) of the CNT12 as in Comparative Example 2.
In this embodiment, the manufacturing apparatus shown in FIG. 4 is used for manufacturing CNTs, but can be used as a manufacturing apparatus for fibrous carbon materials other than CNTs.

1, 11 Substrate 2 Fibrous carbon material 3 Catalyst-derived impurities 4 Transfer film 14 Resin film 5 Laser 6 Blade 7 Reactive gas supply unit 8 Pressure roller 9 Laser irradiation device 12 CNT
14a, 15a Supply rollers 14b, 15b Recovery roller 16 Molten resin 18 Roller 19 Molten resin supply unit 20 Suction device 21, 24 CNT generation unit 22, 25 CNT transfer unit 23, 26 CNT recovery unit

Claims (7)

(1) a step of growing a fibrous carbon material using a catalyst attached to the surface of the substrate as a nucleus;
(2) a step of curing the transfer film after embedding the end portion of the fibrous carbon material opposite to the substrate side and the catalyst-derived impurities attached to the end portion in the softened transfer film;
(3) after the step (2), transferring the fibrous carbon material from the substrate to a transfer film and separating the substrate and impurities derived from the catalyst attached to the surface of the substrate;
(4) The vicinity of the base in the portion exposed from the transfer film in the fibrous carbon material transferred to the transfer film is cut using a cutting means, and most of the fibrous carbon material is transferred to the transfer film in the fibrous carbon material. Separating and recovering from the transfer film embedded with the catalyst-derived impurities attached to the edge and the edge;
The manufacturing method of the fibrous carbon material characterized by including. The transfer film is a resin film having a thickness of 10 to 1000 μm,
2. The method for producing a fibrous carbon material according to claim 1, wherein the resin film is made of a thermoplastic resin or a thermosetting resin.   The method for producing a fibrous carbon material according to claim 2, wherein the thermoplastic resin is at least one selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyimide, and polyvinylidene fluoride.   The method for producing a fibrous carbon material according to claim 2, wherein the thermosetting resin is an epoxy resin.   The method for producing a fibrous carbon material according to any one of claims 1 to 4, wherein the cutting means is a laser or a blade.   The fibrous carbon material according to any one of claims 1 to 5, wherein the fibrous carbon material is grown in the step (1) by reusing the substrate separated in the step (3). Method.   The fibrous carbon material according to any one of claims 1 to 6, wherein an average length of the fibrous carbon material grown on one surface of the substrate in the step (1) is 10 to 1000 µm. Manufacturing method.