Apparatus and method for manufacturing carbon nanotube

Abstract

To provide a carbon nanotube manufacturing apparatus capable of manufacturing a large amount of high quality carbon nanotubes at a lower cost.SOLUTION: A transport line 2 that transports a long substrate sheet S, a sputtering chamber 3 that performs a process of forming a catalyst layer by a sputtering method on the substrate sheet S transported by the transport line 2, a CVD chamber 4 that performs a process of forming a CNT layer on the catalyst layer by a CVD method on the substrate sheet S transported by the transport line 2, and a pressure adjusting unit 5 that is disposed between the sputtering chamber 3 and the CVD chamber 4, the pressure adjusting unit 5 adjusts a pressure difference between the sputtering chamber 3 and the CVD chamber 4 while the base material sheet S is conveyed from the sputtering chamber 3 to the CVD chamber 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for producing carbon nanotubes. [Background technology]

[0002] Carbon nanotubes (CNTs) are nanomaterials made from graphene in the form of a tube; those with one layer are called single-walled carbon nanotubes, and those with multiple layers are called multi-walled carbon nanotubes.

[0003] Compared to steel, CNTs have properties such as 100 times the tensile strength, 5 times the Young's modulus, and one-sixth the density, surpassing carbon fiber, which is also made up of carbon atoms. Furthermore, CNTs have 10 times the thermal conductivity and 1,000 times the electrical resistance of copper, and are also excellent in flexibility, heat resistance, sliding properties, and corrosion resistance.

[0004] As CNTs are good conductors of electricity, have high heat resistance, and have excellent mechanical properties, their use in forms suited to each application, such as CNT fibers, CNT powder, and CNT films, is being considered.

[0005] Meanwhile, technological developments are being made to mass-produce the above-mentioned CNTs at lower cost (see, for example, Patent Documents 1 to 3 below). Patent Documents 1 to 3 below disclose CNT production equipment using the so-called roll-to-roll method, in which a stainless steel sheet is unwound from an unwinding roll, CNTs are formed on the surface of the unwound stainless steel sheet, and then the stainless steel sheet with the CNTs formed thereon is wound up on a winding roll. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-174097 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-032248 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-231446 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the CNT manufacturing apparatus employing the above-mentioned roll-to-roll method is required to be further improved in order to mass-produce high-quality CNTs at lower cost.

[0008] The present invention has been proposed in consideration of the above-mentioned conventional circumstances, and aims to provide a carbon nanotube manufacturing apparatus and manufacturing method that enable high-quality carbon nanotubes to be mass-produced at a lower cost. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides the following means. [1] A conveying line for conveying a long base sheet; a sputtering chamber for performing a process of forming a catalyst layer on the base sheet transported on the transport line by a sputtering method; a chemical vapor deposition (CVD) chamber for forming a carbon nanotube (CNT) layer on the catalyst layer by a chemical vapor deposition (CVD) method on the substrate sheet transported on the transport line; a pressure adjusting unit disposed between the sputtering chamber and the CVD chamber; The pressure adjusting unit adjusts the pressure difference between the sputtering chamber and the CVD chamber while the base sheet is being transported from the sputtering chamber to the CVD chamber. [2] The carbon nanotube manufacturing apparatus according to [1], wherein the pressure adjusting unit includes a buffer chamber disposed between the sputtering chamber and the CVD chamber, and adjusts the pressure difference within the buffer chamber. [3] An accumulator unit is provided between the sputtering chamber and the CVD chamber of the transfer line, The carbon nanotube manufacturing apparatus according to [1] or [2], wherein the accumulator section adjusts the feed rate of the base sheet transported from the sputtering chamber to the CVD chamber. [4] In the sputtering chamber, the base sheet is processed while the transport of the base sheet is continued; The carbon nanotube manufacturing apparatus according to [3], wherein the substrate sheet is treated in the CVD chamber while the transport of the substrate sheet is stopped. [5] The carbon nanotube manufacturing apparatus according to any one of [1] to [4], wherein the base sheets arranged in a plurality of stages are treated inside the CVD chamber. [6] The carbon nanotube manufacturing apparatus according to [5], wherein the transfer line transfers the substrate sheet in a folded manner inside the CVD chamber. [7] The carbon nanotube manufacturing apparatus according to any one of [1] to [6], further comprising a recovery section that separates and recovers the CNT layer from the base sheet. [8] The conveying line includes an unwinding roll that unwinds the base sheet and a winding roll that winds the base sheet, The carbon nanotube manufacturing apparatus according to [7], wherein the take-up roll takes up the base sheet, and then the unwinding roll unwinds the base sheet, thereby repeatedly transporting the base sheet. [9] A step of transporting a long base sheet by a transport line; a step of performing a process of forming a catalyst layer on the base sheet transported on the transport line by a sputtering method in a sputtering chamber; a step of forming a carbon nanotube (CNT) layer on the catalyst layer by chemical vapor deposition (CVD) in a CVD chamber for the base sheet transported on the transport line; and adjusting a pressure difference between the sputtering chamber and the CVD chamber while the base sheet is being transported from the sputtering chamber to the CVD chamber. [Effects of the Invention]

[0010] According to the present invention, there are provided a carbon nanotube manufacturing apparatus and method that enable high-quality carbon nanotubes to be mass-produced at lower cost. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing the configuration of a carbon nanotube manufacturing apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, characteristic portions may be enlarged for convenience in order to make the features easier to understand, and the dimensional ratios of each component may not be the same as in reality. Furthermore, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not necessarily limited to them, and can be implemented with appropriate changes within the scope of the present invention.

[0013] As one embodiment of the present invention, for example, a carbon nanotube (hereinafter referred to as CNT) manufacturing apparatus 1 shown in FIG. 1 and a CNT manufacturing method using this manufacturing apparatus 1 will be described. FIG. 1 is a schematic diagram showing the configuration of a CNT manufacturing apparatus 1.

[0014] As shown in FIG. 1, the manufacturing apparatus 1 of this embodiment is a CNT manufacturing apparatus that employs a roll-to-roll method, and enables high-quality CNTs to be mass-produced at lower cost.

[0015] Specifically, this manufacturing apparatus 1 includes a conveying line 2 for conveying a long substrate sheet S, a sputtering chamber 3 for performing a process of forming a buffer layer and a catalyst layer in sequence on the substrate sheet S conveyed on the conveying line 2 by sputtering, a CVD chamber 4 for performing a process of forming a CNT layer on the catalyst layer on the substrate sheet S conveyed on the conveying line 2 by chemical vapor deposition (CVD), a pressure adjustment unit 5 for adjusting the pressure difference between the sputtering chamber 3 and the CVD chamber 4, an accumulator unit 6 for adjusting the feed rate of the substrate sheet S conveyed from the sputtering chamber 3 to the CVD chamber 4, a recovery unit 7 for separating and recovering the CNT layer from the substrate sheet S, and a cleaning unit 8 for cleaning the substrate sheet S from which the CNT layer has been separated.

[0016] In addition, the method for manufacturing CNTs using the manufacturing apparatus 1 of this embodiment includes the steps of transporting a long substrate sheet S along a transport line 2, performing a process of forming a catalyst layer on the substrate sheet S transported along the transport line 2 by a sputtering method in a sputtering chamber 3, performing a process of forming a CNT layer on the catalyst layer on the substrate sheet S transported along the transport line 2 by a CVD method in a CVD chamber 4, and adjusting the pressure difference between the sputtering chamber 3 and the CVD chamber 4 by a pressure adjustment unit 5 while the substrate sheet S is transported from the sputtering chamber 3 to the CVD chamber 4.

[0017] In this embodiment, a process for laminating a buffer layer and a catalyst layer in this order is performed on both sides of the base sheet S. Alternatively, a process for laminating a buffer layer and a catalyst layer in this order may be performed on one side of the base sheet S.

[0018] The conveying line 2 has an unwinding roll 9 that unwinds the base sheet S and a winding roll 10 that winds up the base sheet S. The unwinding roll 9 is housed in an unwinding chamber 11 and is provided so as to be rotatable about its axis. The winding roll 10 is housed in a winding chamber 12 and is provided so as to be rotatable about its axis.

[0019] In the conveying line 2, the base sheet S is conveyed between the unwinding roll 9 and the winding roll 10. In addition, in the conveying line 2, by controlling the rotation directions of the unwinding roll 9 and the winding roll 10, it is possible to wind the base sheet S from the unwinding roll 9 onto the winding roll 10 and to rewind the base sheet S from the winding roll 10 onto the unwinding roll 9.

[0020] In this embodiment, a sheet made of a conductive metal such as stainless steel can be used as the base sheet S. The thickness of the base sheet S is, for example, about 10 to 300 μm, and the base sheet S is formed in a long foil shape with a constant width.

[0021] The sputtering chamber 3 is a chamber that can be decompressed by connecting a vacuum pump (not shown), and is connected to the unwinding chamber 11. In the sputtering chamber 3, for example, 10 -1 A process is performed on the base sheet S by sputtering in a reduced pressure atmosphere on the order of Pa to form a buffer layer and a catalyst layer in this order. In the sputtering chamber 3, the base sheet S is processed while being transported.

[0022] The buffer layer is a layer interposed between the base sheet S and the catalyst layer to prevent chromium (Cr) deposited from the base sheet S, for example made of stainless steel, when heated during thermal CVD, which will be described later, from adversely affecting the catalyst layer. In this embodiment, an insulating film such as silica (SiO2) is formed as a thin film on both sides of the base sheet S as the buffer layer.

[0023] It should be noted that the base sheet S does not necessarily have to be made of stainless steel as described above, and other base sheets S can also be used. The buffer layer is not necessarily required, and can be omitted depending on the material of the base sheet S, etc.

[0024] The catalyst layer is a layer for promoting the growth of the CNT layer. In this embodiment, as the catalyst layer, metal particles such as iron (Fe) are carried on the base sheet S, for example, on the buffer layer.

[0025] The CVD chamber 4 is placed under an atmosphere with a higher pressure than the sputtering chamber 3, specifically, for example, 10 5 In an atmosphere of normal pressure of about Pa, a treatment is performed on both sides of the substrate sheet S to form a CNT layer on the catalyst layer by a CVD method.

[0026] It should be noted that the CVD4 may be performed in a chamber that can be depressurized by connecting a vacuum pump (not shown). The CNT layer may be formed under a reduced or pressurized atmosphere, not limited to normal pressure.

[0027] The thermal CVD method is preferably used to form the CNT layer. Specifically, a carbon-containing source gas, such as methane, ethane, ethylene, acetylene, alcohol, or carbon monoxide, is introduced into the CVD chamber 4 through a source gas inlet pipe (not shown) connected to the CVD chamber 4. The source gas is decomposed on the substrate sheet S heated to, for example, about 600 to 800°C, while growing CNTs on the catalyst layer, thereby forming the CNT layer. The substrate sheet S is heated by passing electricity through the substrate sheet S or by using a heater.

[0028] In the CVD chamber 4 of this embodiment, for example, processing is performed on base sheets S arranged in parallel in multiple stages. For this reason, the conveying line 2 is configured to convey the base sheets S by turning them over inside the CVD chamber 4, for example.

[0029] Specifically, a pair of recovery chambers 14a, 14b are connected to both sides of the CVD chamber 4 via a pair of gate valves 13a, 13b. The pair of gate valves 13a, 13b are provided with shutters (not shown) that open and close the inlet and outlet sides of the CVD chamber 4 for each of the base sheets S arranged in parallel in multiple stages. Inside the pair of recovery chambers 14a, 14b, a plurality of turn-back rolls 15a, 15b are provided, each lined up in the vertical direction.

[0030] In the conveying line 2, the base sheet S is alternately folded back between a plurality of folding back rolls 15a arranged on one side of the recovery chamber 14a and a plurality of folding back rolls 15b arranged on the other side of the recovery chamber 14b, and the base sheet S is conveyed in a folded back manner between the entrance side and exit side of the CVD chamber 4. This makes it possible to process the base sheets S arranged in parallel in multiple stages inside the CVD chamber 4.

[0031] In the CVD chamber 4, processing is performed on the base sheet S while the transport of the base sheet S is stopped. Therefore, while the base sheet S is stopped, the pair of gate valves 13a, 13b are closed with the shutters sandwiching the base sheet S. On the other hand, while the base sheet S is being transported, the pair of gate valves 13a, 13b are open with the shutters separated from the base sheet S.

[0032] The pressure adjusting unit 5 has a buffer chamber 16, the interior of which can be decompressed by connecting a vacuum pump (not shown). The buffer chamber 16 is connected to the outlet side of the sputtering chamber 3. The buffer chamber 16 adjusts the pressure difference between the sputtering chamber 3 and the CVD chamber 4 while the base sheet S is being transported from the sputtering chamber 3 to the CVD chamber 4.

[0033] The accumulator section 6 has a configuration in which a pair of guide rolls 18a located on both sides in the conveying direction of the base sheet S, a plurality of first rollers 18b located on the upper side between the pair of guide rolls 18a, and a plurality of second rollers 18c located on the lower side between the pair of guide rolls 18a are arranged alternately inside an accumulator chamber 17. The accumulator chamber 17 is connected between the buffer chamber 16 and the recovery chamber 14a.

[0034] In the accumulator section 6, the base sheet S is transported while being alternately folded back and forth between a plurality of first rollers 18b lined up on the upper side and a plurality of second rollers 18c lined up on the lower side, and by raising and lowering the first rollers 18b on the upper side and the second rollers 18c on the lower side in the vertical direction, it is possible to change the transport distance of the base sheet S without stopping the transport line 2.

[0035] Specifically, in this accumulator unit 6, the conveying distance of the base sheet S can be increased by widening the distance between the upper first roller 18b and the lower second roller 18c. On the other hand, the conveying distance of the base sheet S can be reduced by narrowing the distance between the upper first roller 18b and the lower second roller 18c.

[0036] This makes it possible to adjust the feed rate of the base sheet S transported from the sputtering chamber 3 to the CVD chamber 4, and absorb the difference in feed speed of the base sheet S that occurs between the sputtering chamber 3 and the CVD chamber 4 described above.

[0037] The recovery unit 7 uses a member (not shown) for recovering the CNT layer from the base sheet, such as a squeegee, which is arranged inside the pair of recovery chambers 14a, 14b, to peel the CNT layer from the surface of the base sheet S, and then recovers the CNTs separated from the base sheet S by sucking them with a suction machine (not shown).

[0038] In the manufacturing apparatus 1 of this embodiment, in order to process the base sheets S arranged in multiple tiers inside the CVD chamber 4 described above, a member for recovering the CNT layer from the base sheets, such as a squeegee, is provided at each outlet side of the base sheets S arranged in multiple tiers.

[0039] The recovery of the CNTs separated from the base sheet S is not limited to the recovery method using the suction machine described above, and the CNTs accumulated in the recovery chambers 14a and 14b may be collected.

[0040] The cleaning unit 8 cleans both surfaces of the base sheet S from which the CNT layer has been separated, using a brush, cleaning roll, etc. (not shown) arranged inside the cleaning chamber 19. The cleaning chamber 19 is connected between the recovery chamber 14b and the winding chamber 12.

[0041] In the manufacturing apparatus 1 of this embodiment, after the above-described winding roll 10 winds up the base sheet S, the unwinding roll 9 unwinds the base sheet S, thereby making it possible to repeatedly transport the base sheet S. In other words, it is possible to repeatedly manufacture CNTs using the base sheet S after cleaning.

[0042] Furthermore, when the base sheet S is reused after cleaning, it is possible to omit the formation of the buffer layer and catalyst layer in the sputtering chamber 3. That is, when the state of the base sheet S after cleaning is checked and it is determined that the formation of the buffer layer and catalyst layer is not necessary, it is possible to skip the process of forming the buffer layer and catalyst layer in the sputtering chamber 3 and directly perform the process of forming the CNT layer in the CVD chamber 4.

[0043] As described above, the method for producing CNTs using the production apparatus 1 of this embodiment makes it possible to mass-produce high-quality CNTs at lower cost.

[0044] The present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the pressure adjustment unit 5 is configured such that the buffer chamber 16 is arranged between the sputtering chamber 3 and the accumulator chamber 17, but the buffer chamber 16 may be arranged between the sputtering chamber 3 and the CVD chamber 4, and for example, the buffer chamber 16 may be arranged between the accumulator chamber 17 and the recovery chamber 14a.

[0045] Furthermore, the pressure adjustment unit 5 is not limited to a configuration in which the buffer chamber 16 is provided as described above, but may be configured, for example, in which a mechanism for adjusting the pressure difference between the sputtering chamber 3 and the CVD chamber 4 is provided in the accumulator chamber 17, the recovery chamber 14a, or the gate valve 13a.

[0046] Furthermore, in the manufacturing apparatus 1, the base sheet S is configured to be conveyed inside the CVD chamber 4 in a folded manner, but a configuration in which multiple base sheets S are conveyed in parallel inside the CVD chamber 4 may also be used. [Explanation of symbols]

[0047] REFERENCE SIGNS LIST 1... Manufacturing equipment 2... Transfer line 3... Sputtering chamber 4... CVD chamber 5... Pressure adjustment section 6... Accumulator section 7... Recovery section 8... Cleaning section 9... Unwinding roll 10... Winding roll 16... Buffer chamber S... Base material sheet

Claims

1. a conveying line for conveying a long base material sheet; a sputtering chamber for performing a process of forming a catalyst layer on the base sheet transported on the transport line by a sputtering method; a chemical vapor deposition (CVD) chamber for performing a process of forming a carbon nanotube (CNT) layer on the catalyst layer by a chemical vapor deposition (CVD) method on the base sheet transported on the transport line; a pressure adjusting unit disposed between the sputtering chamber and the CVD chamber; The pressure adjusting unit adjusts the pressure difference between the sputtering chamber and the CVD chamber while the base sheet is being transported from the sputtering chamber to the CVD chamber.

2. 2. The carbon nanotube manufacturing apparatus according to claim 1, wherein the pressure adjusting unit includes a buffer chamber disposed between the sputtering chamber and the CVD chamber, and adjusts the pressure difference within the buffer chamber.

3. an accumulator unit interposed between the sputtering chamber and the CVD chamber on the transfer line; 2. The carbon nanotube manufacturing apparatus according to claim 1, wherein the accumulator adjusts the feed rate of the base sheet transported from the sputtering chamber to the CVD chamber.

4. In the sputtering chamber, the base sheet is treated while the transport of the base sheet is continued; 4. The carbon nanotube manufacturing apparatus according to claim 3, wherein the substrate sheet is treated in the CVD chamber while the transport of the substrate sheet is stopped.

5. 2. The carbon nanotube manufacturing apparatus according to claim 1, wherein the substrate sheets arranged in a plurality of stages inside the CVD chamber are processed.

6. 6. The carbon nanotube manufacturing apparatus according to claim 5, wherein the transfer line transfers the base sheet in a folded manner inside the CVD chamber.

7. The carbon nanotube manufacturing apparatus according to claim 1 , further comprising a recovery unit that separates and recovers the CNT layer from the substrate sheet.

8. the conveying line includes an unwinding roll that unwinds the base sheet and a winding roll that winds the base sheet, 8. The carbon nanotube manufacturing apparatus according to claim 7, wherein the substrate sheet is repeatedly transported by the take-up roll winding the substrate sheet and then the unwinding roll unwinding the substrate sheet.

9. A step of conveying a long base material sheet by a conveying line; a step of performing a process of forming a catalyst layer on the base sheet transported on the transport line by a sputtering method in a sputtering chamber; a step of forming a carbon nanotube (CNT) layer on the catalyst layer by chemical vapor deposition (CVD) in a CVD chamber for the base sheet transported on the transport line; and adjusting a pressure difference between the sputtering chamber and the CVD chamber while the base sheet is being transported from the sputtering chamber to the CVD chamber.

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