Method for manufacturing carbon nanotube bundles and apparatus for manufacturing carbon nanotube bundles

Abstract

The method for producing a carbon nanotube strand wire of the present disclosure is a method for producing a carbon nanotube strand wire provided with a first step for growing carbon nanotubes from each of a plurality of catalyst particles by supplying carbon-containing gas to a plurality of suspended catalyst particles within a tubular carbon nanotube synthesis furnace to obtain a plurality of carbon nanotubes and a second step for aggregating the plurality of carbon nanotubes to obtain a plurality of carbon nanotube strand wires, in which the second step is provided with a step 2A for orienting and aggregating a first carbon nanotube group composed of some of the plurality of carbon nanotubes along the longitudinal direction of the carbon nanotubes within a first flow path to obtain a first carbon nanotube strand wire and a step 2B for orienting and aggregating a second carbon nanotube group composed of some of the carbon nanotubes different from the plurality of carbon nanotubes that compose the first carbon nanotube group along the longitudinal direction of the carbon nanotubes within a second flow path to obtain a second carbon nanotube strand wire.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a carbon nanotube assembly wire and a carbon nanotube assembly wire manufacturing apparatus. This application claims priority based on Japanese Patent Application No. 2021-028388, filed on February 25, 2021. All the descriptions set forth in the Japanese patent application are incorporated herein by reference.

Background Art

[0002] A carbon nanotube (hereinafter also referred to as "CNT") having a structure in which graphene sheets with carbon atoms bonded in a hexagonal shape are formed into a cylindrical shape is a material that is 1 / 5 as light as copper and has a strength 20 times that of steel and excellent electrical conductivity. Therefore, an electric wire using carbon nanotubes is expected as a material that contributes particularly to weight reduction, miniaturization, and corrosion resistance improvement of automotive motors.

[0003] Currently produced carbon nanotubes have a diameter of about 0.4 nm to 20 nm and a maximum length of about 55 cm. In order to use carbon nanotubes as electric wires or high-strength materials, it is necessary to obtain longer wire materials, and technologies for obtaining elongated wire materials using carbon nanotubes have been studied.

[0004] For example, International Publication No. 2020 / 138378 (Patent Document 1) discloses a method for obtaining an elongated carbon nanotube assembly wire by aligning and aggregating a plurality of carbon nanotubes in their longitudinal directions.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] The manufacturing method of the carbon nanotube assembly line of the present disclosure is as follows: In a tubular carbon nanotube synthesis furnace, by supplying a carbon-containing gas to a plurality of floating catalyst particles, a first step of growing carbon nanotubes from each of the plurality of catalyst particles to obtain a plurality of carbon nanotubes is carried out. It includes a second step of aggregating the plurality of carbon nanotubes to obtain a plurality of carbon nanotube assembly lines. The second step is as follows: A first carbon nanotube group composed of a part of the plurality of carbon nanotubes is oriented and aggregated along the longitudinal direction of the carbon nanotubes in a first flow path to obtain a first carbon nanotube assembly line in a first step 2A. A second carbon nanotube group composed of a part of the plurality of carbon nanotubes different from the plurality of carbon nanotubes constituting the first carbon nanotube group is oriented and aggregated along the longitudinal direction of the carbon nanotubes in a second flow path to obtain a second carbon nanotube assembly line in a second step 2B. The manufacturing method of the carbon nanotube assembly line is provided with these steps.

[0007] The carbon nanotube assembly line manufacturing apparatus is as follows: A tubular carbon nanotube synthesis furnace, A carbon-containing gas supply port provided on one end side of the carbon nanotube synthesis furnace, A first flow path and a second flow path provided on the end side opposite to the end where the carbon-containing gas supply port of the carbon nanotube synthesis furnace is provided. The carbon nanotube assembly line manufacturing apparatus is provided with these components. The first flow path and the second flow path are provided in parallel along the longitudinal direction of the carbon nanotube synthesis furnace. The cross-sectional area of each of the first flow path and the second flow path is smaller than the cross-sectional area of the carbon nanotube synthesis furnace.

Brief Description of the Drawings

[0008] [Figure 1]Figure 1 is a flowchart showing a method for manufacturing carbon nanotube bundles according to Embodiment 1. [Figure 2] Figure 2 shows an example of a carbon nanotube bundle wire manufacturing apparatus according to Embodiment 2. [Figure 3] Figure 3 is a flowchart showing the method for manufacturing carbon nanotube bundles according to Embodiment 3. [Figure 4] Figure 4 shows an example of a carbon nanotube bundle wire manufacturing apparatus according to Embodiment 4. [Figure 5] Figure 5 shows an example of the main surface of the 1-1 structure. [Figure 6] Figure 6 is a cross-sectional view of the first and second channels provided in the CNT bundle wire manufacturing apparatus shown in Figure 4, in a direction along the longitudinal direction of the CNT synthesis furnace. [Figure 7] Figure 7 shows an example of a carbon nanotube bundle wire manufacturing apparatus according to Embodiment 5. [Figure 8] Figure 8 shows an example of the main surface on the carbon-containing gas supply port side of the 1-3 structure. [Figure 9] Figure 9 shows an example of the main surface on the carbon-containing gas supply port side and the main surface on the opposite side of the 1-3 structure. [Figure 10] Figure 10 shows an example of a cross-section of the first to third structures. [Figure 11] Figure 11 shows apparatus 4 (a comparative example of a carbon nanotube bundled wire manufacturing apparatus). [Figure 12] Figure 12 shows a cross-section of the 1-1 structure of apparatus 5 (a comparative example carbon nanotube bundle wire manufacturing apparatus). [Modes for carrying out the invention]

[0009] [Issues this disclosure aims to address] The technology described in Patent Document 1 allows for the production of one carbon nanotube bundle from a single carbon nanotube synthesis furnace. However, from the standpoint of production efficiency, a technology is desired that can produce multiple carbon nanotube bundles from a single carbon nanotube synthesis furnace.

[0010] Therefore, one of the objectives of this invention is to provide a method for producing multiple carbon nanotube bundles using a single carbon nanotube synthesis furnace. Another objective of this invention is to provide a carbon nanotube bundle manufacturing apparatus capable of producing multiple carbon nanotube bundles using a single carbon nanotube synthesis furnace.

[0011] [Effects of this disclosure] According to this disclosure, it is possible to produce multiple carbon nanotube bundles using a single carbon nanotube synthesis furnace.

[0012] [Description of Embodiments in this Disclosure] First, the embodiments of this disclosure will be listed and described. (1) The method for producing carbon nanotube bundles according to the present disclosure is: The first step involves supplying a carbon-containing gas to multiple suspended catalyst particles in a tubular carbon nanotube synthesis furnace, thereby growing carbon nanotubes from each of the multiple catalyst particles to obtain multiple carbon nanotubes. The system comprises a second step of assembling the aforementioned plurality of carbon nanotubes to obtain a plurality of carbon nanotube bundle lines, The second step is, Step 2A involves aligning and assembling a first carbon nanotube group, composed of a portion of the plurality of carbon nanotubes, in a first channel along the longitudinal direction of the carbon nanotubes to obtain a first carbon nanotube assembly line. A method for producing a carbon nanotube bundle, comprising: step 2B, which involves aligning and assembling a second carbon nanotube bundle, which is composed of a portion of the plurality of carbon nanotubes different from the plurality of carbon nanotubes that constitute the first carbon nanotube bundle, in a second channel along the longitudinal direction of the carbon nanotubes to obtain a second carbon nanotube bundle.

[0013] According to this disclosure, it is possible to produce multiple carbon nanotube bundles using a single carbon nanotube synthesis furnace.

[0014] (2) The first carbon nanotube group includes a first A carbon nanotube group composed of a portion of the plurality of carbon nanotubes constituting the first carbon nanotube group, and a first a carbon nanotube group composed of a portion of the plurality of carbon nanotubes constituting the first carbon nanotube group that are different from the plurality of carbon nanotubes constituting the first A carbon nanotube group, The first channel includes a first-1A channel and a first-1a channel arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace, and a first-2 channel provided downstream of the carbon-containing gas flow in the first-1A channel and the first-1a channel. The above-mentioned 2A step is, Step 2A-1A involves assembling the group of carbon nanotubes described above in the channel 1-1A in an orientation along the longitudinal direction of the carbon nanotubes to obtain a bundled wire of carbon nanotubes described above. Step 2A-1a involves assembling the group of carbon nanotubes in the channel 1-1a in an orientation along the longitudinal direction of the carbon nanotubes to obtain a bundled wire of carbon nanotubes, The process includes a second A-2 step of assembling a plurality of carbon nanotube bundle wires, including the first A carbon nanotube bundle wire and the first a carbon nanotube bundle wire, in the first-2 channel, oriented along the longitudinal direction of the carbon nanotube bundle wires to obtain the first carbon nanotube bundle wire, The second carbon nanotube group includes a second B carbon nanotube group composed of a portion of the multiple carbon nanotubes constituting the second carbon nanotube group, and a second b carbon nanotube group composed of a portion of the multiple carbon nanotubes constituting the second carbon nanotube group that are different from the multiple carbon nanotubes constituting the second B carbon nanotube group. The second channel includes a second-1B channel and a second-1b channel provided in parallel along the longitudinal direction of the carbon nanotube synthesis furnace, and a second-2 channel provided downstream of the carbon-containing gas flow in the second-1B channel and the second-1b channel. The 2B step is, The second B-1B step involves assembling the second B carbon nanotube group in the second B channel in an orientation along the longitudinal direction of the carbon nanotubes to obtain a second B carbon nanotube bundle wire, The second B-1b step involves assembling the second b carbon nanotube group in the second B channel in an orientation along the longitudinal direction of the carbon nanotubes to obtain a second b carbon nanotube bundle wire, Preferably, the process includes a second B-2 step, in which a plurality of carbon nanotube bundle wires, including the second B carbon nanotube bundle wire, are assembled in the second B-2 channel in an orientation along the longitudinal direction of the carbon nanotube bundle wire to obtain the second carbon nanotube bundle wire.

[0015] According to this, carbon nanotubes aggregate to form carbon nanotube aggregate wires, and these carbon nanotube aggregate wires further aggregate to form carbon nanotube aggregate lines. These carbon nanotube aggregate lines are easily made longer. It is preferable to draw the CNTs generated in the first channel into the second-first channel and the second-second channel by suction.

[0016] (3) The carbon nanotube assembly wire manufacturing apparatus of the present disclosure A tubular carbon nanotube synthesis furnace, A carbon-containing gas supply port is provided on one end side of the carbon nanotube synthesis furnace, The carbon nanotube synthesis furnace comprises a first channel and a second channel provided on the end opposite to the end where the carbon-containing gas supply port is located, The first channel and the second channel are provided in parallel along the longitudinal direction of the carbon nanotube synthesis furnace. The carbon nanotube bundle manufacturing apparatus is such that the cross-sectional areas of the first channel and the second channel are smaller than the cross-sectional area of ​​the carbon nanotube synthesis furnace.

[0017] According to this disclosure, it is possible to produce multiple carbon nanotube bundles using a single carbon nanotube synthesis furnace.

[0018] (4) The first channel includes a first-1A channel and a first-1a channel provided in parallel on the carbon-containing gas supply port side of the carbon nanotube synthesis furnace, and a first-2 channel provided on the side of the first-1A channel and the first-1a channel opposite to the carbon-containing gas supply port, Preferably, the second channel includes a second-1B channel and a second-1b channel provided in parallel on the carbon-containing gas supply port side of the carbon nanotube synthesis furnace, and a second-2 channel provided on the side of the second-1B channel and the second-1b channel opposite to the carbon-containing gas supply port.

[0019] According to this, carbon nanotubes aggregate to form carbon nanotube bundled wires, and these carbon nanotube bundled wires further aggregate to form carbon nanotube bundled wires. These carbon nanotube bundled wires are easily made into long lengths.

[0020] (5) The 1-1A channel, the 1-1a channel, the 2-1B channel, and the 2-1b channel are provided in the same 1-1 structure, The first- and second channels are provided in a first- and second structure that is different from the first- and first-first structure. It is preferable that the 2-2 channel is provided in a 2-2 structure that is different from the 1-1 structure.

[0021] According to this, carbon nanotubes and carbon nanotube aggregation lines tend to aggregate in an orientation along the longitudinal direction.

[0022] (6) The 1-1A channel, the 1-1a channel, the 1-2 channel, the 2-1B channel, the 2-1b channel and the 2-2 channel are provided in the same 1-3 structure, The ends of the 1-1A channel and the 1-1a channel opposite to the carbon-containing gas supply port are connected to the end of the 1-2 channel on the carbon-containing gas supply port side. Preferably, the ends of the 2-1B channel and the 2-1b channel opposite to the carbon-containing gas supply port are connected to the end of the 2-2 channel on the carbon-containing gas supply port side.

[0023] According to this, carbon nanotubes and carbon nanotube aggregation lines tend to aggregate in an orientation along the longitudinal direction.

[0024] [Details of the embodiments of this disclosure] Specific examples of the carbon nanotube bundle wire manufacturing method and carbon nanotube bundle wire manufacturing apparatus described herein will be explained below with reference to the drawings. In the drawings of this disclosure, the same reference numerals indicate the same or equivalent parts. Furthermore, dimensional relationships such as length, width, thickness, and depth have been appropriately modified for clarity and simplification of the drawings and do not necessarily represent actual dimensional relationships.

[0025] In this specification, the notation "A~B" means an upper and lower limit of a range (i.e., greater than or equal to A and less than or equal to B). If no unit is specified for A, but a unit is specified only for B, then the units for A and B are the same.

[0026] [Embodiment 1: Method for manufacturing carbon nanotube bundles (1)] A method for manufacturing carbon nanotube bundles according to one embodiment of the present disclosure (hereinafter also referred to as "this embodiment") will be described with reference to Figures 1 and 2. Figure 1 is a flowchart showing the method for manufacturing carbon nanotube bundles (hereinafter also referred to as "CNT bundles") according to this embodiment. Figure 2 is a diagram showing an example of a carbon nanotube bundle manufacturing apparatus used in the method for manufacturing carbon nanotube bundles according to this embodiment.

[0027] As shown in Figures 1 and 2, the method for producing a carbon nanotube bundle of wires according to this embodiment comprises: a first step of growing carbon nanotubes 1 from each of a plurality of suspended catalyst particles 27 by supplying a carbon-containing gas to a plurality of suspended catalyst particles 27 in a tubular carbon nanotube synthesis furnace (hereinafter also referred to as "CNT synthesis furnace") 60, thereby obtaining a plurality of carbon nanotubes 1; and a second step of assembling the plurality of carbon nanotubes 1 to obtain a plurality of carbon nanotube bundle of wires. The second step comprises: a second A step of assembling a first carbon nanotube group 11, composed of a portion of the plurality of carbon nanotubes, in a first channel 41 oriented along the longitudinal direction of the carbon nanotubes to obtain a first carbon nanotube bundle of wires 31; and a second B step of assembling a second carbon nanotube group 12, composed of a portion of a plurality of carbon nanotubes different from the plurality of carbon nanotubes constituting the first carbon nanotube group 11, in a second channel 42 oriented along the longitudinal direction of the carbon nanotubes to obtain a second carbon nanotube bundle of wires 32. It is preferable that the multiple carbon nanotubes constituting the first carbon nanotube group 11 remain separated before entering the first channel 41, without forming a network that inhibits separation. Similarly, it is preferable that the multiple carbon nanotubes constituting the second carbon nanotube group 12 remain separated before entering the second channel 42, without forming a network that inhibits separation. This prevents clogging of the multiple carbon nanotubes near the entrance of the first channel and near the entrance of the second channel.

[0028] According to the carbon nanotube bundle wire manufacturing method of this embodiment, multiple carbon nanotube bundle wires can be obtained using a single carbon nanotube synthesis furnace. This facilitates the scaling up of CNT synthesis furnaces and mass production of CNT bundle wires, thereby reducing the manufacturing cost of CNT bundle wires.

[0029] <1st process> In a tubular carbon nanotube synthesis furnace 60, a carbon-containing gas is supplied to a plurality of suspended catalyst particles 27, thereby growing carbon nanotubes 1 from each of the plurality of catalyst particles 27 in a first step to obtain a plurality of carbon nanotubes 1.

[0030] The first step is preferably carried out under temperature conditions of, for example, 800°C to 1500°C. Under these temperature conditions, the carbon-containing gas is thermally decomposed, and carbon crystals grow on the suspended catalyst particles to form carbon nanotubes. CNTs can also be grown between multiple catalyst particles by separating multiple catalyst particles that are in close contact within a flow of carbon-containing gas.

[0031] When the temperature is 800°C or higher, the carbon crystal growth rate is faster, and production efficiency is improved. On the other hand, when the temperature is 1500°C or lower, the content of impurity carbon decreases, and the quality of CNTs is improved. The temperature conditions for the first process are more preferably between 900°C and 1400°C, and even more preferably between 950°C and 1250°C.

[0032] In Figure 2, catalyst particles 27 are suspended in the carbon-containing gas supplied to the CNT synthesis furnace 60. These catalyst particles 27 are formed when a catalyst (not shown) obtained by spraying a slurry containing a dissolved catalyst material from a spray nozzle located near the carbon-containing gas supply port inside the CNT synthesis furnace 60 is heated and disintegrates into particles due to the air pressure of the carbon-containing gas.

[0033] Examples of catalyst materials include ferrocene (Fe(C5H5)2), nickelosene (Ni(C5H5)2), cobaltosene (Co(C5H5)2, etc.). Among these, ferrocene is preferred from the viewpoint of excellent disintegration properties and catalytic activity, and the ability to obtain long carbon nanotubes (CNTs). It is thought that when ferrocene is heated to a high temperature and exposed to a carbon-containing gas, iron carbide (Fe3C) is formed on the surface by carburization, making it easier to disintegrate from the surface, thereby sequentially releasing catalyst particles 27. In this case, the main component of the formed catalyst particles 27 is iron carbide or iron.

[0034] Other catalyst particles 27 that can be used include, for example, nickel, cobalt, molybdenum, gold, silver, copper, palladium, and platinum.

[0035] The lower limit of the average diameter of the catalyst particles 27 is preferably 0.4 nm or more, more preferably 1 nm or more, and even more preferably 2 nm or more. On the other hand, the upper limit of the average diameter of the catalyst particles 27 is preferably 20 nm or less, more preferably 10 nm or less, and even more preferably 5 nm or less.

[0036] The carbon-containing gas is supplied to the CNT synthesis furnace 60 from the carbon-containing gas supply port 62. A reducing gas such as a hydrocarbon gas is used as the carbon-containing gas. Examples of such carbon-containing gases include a mixture of methane and argon, a mixture of ethylene and argon, a mixture of ethanol and argon, a mixture of ethylene and hydrogen, a mixture of methane and hydrogen, and a mixture of ethanol and hydrogen. The carbon-containing gas preferably contains carbon disulfide (CS2) as an auxiliary catalyst.

[0037] The lower limit of the average flow velocity of the carbon-containing gas supplied from the carbon-containing gas supply port 62 in the CNT synthesis furnace is preferably 0.05 cm / sec or higher, more preferably 0.10 cm / sec or higher, and even more preferably 0.20 cm / sec or higher. On the other hand, the upper limit of the average flow velocity in the CNT synthesis furnace 60 is preferably 50 cm / sec or lower, and more preferably 5.0 cm / sec or lower. When the average flow velocity of the carbon-containing gas in the CNT synthesis furnace 60 is 0.05 cm / sec or higher, the amount of carbon-containing gas supplied to the catalyst particles 27 is sufficient, and the growth of carbon nanotubes synthesized between the catalyst particles 27 is promoted. On the other hand, when the average flow velocity of the carbon-containing gas in the CNT synthesis furnace 60 is 10.0 cm / sec or lower, it is possible to suppress the detachment of carbon nanotubes from the catalyst particles 27 and the cessation of carbon nanotube growth.

[0038] The lower limit of the Reynolds number of the flow of carbon-containing gas supplied from the carbon-containing gas supply port 62 within the CNT synthesis furnace 60 is preferably 0.01 or higher, and more preferably 0.05 or higher. On the other hand, the upper limit of the Reynolds number is preferably 1000 or lower, more preferably 100 or lower, and even more preferably 10 or lower. When the Reynolds number is 0.01 or higher, the degree of freedom in the design of the apparatus is improved. ga 1 When the value is 000 or less, it is possible to suppress the disruption of the carbon-containing gas flow, which inhibits the orientation of carbon nanotubes between catalyst particles 27.

[0039] Examples of carbon nanotubes 1 obtained in the first step include single-walled carbon nanotubes, which have only one layer of carbon (graphene) in a tubular shape, and double-walled or multi-walled carbon nanotubes, which have multiple layers of carbon stacked in a tubular shape.

[0040] The shape of the carbon nanotube is not particularly limited, and examples include those with a closed tip or an open tip. Further, catalyst particles 27 used during the synthesis of the carbon nanotube may adhere to one or both ends of the carbon nanotube 1. Also, a cone portion made of conical graphene may be formed at one or both ends of the carbon nanotube 1.

[0041] The length of the carbon nanotube is preferably, for example, 1 μm or more, and more preferably 10 μm or more. In particular, when the length of the carbon nanotube is 100 μm or more, it is suitable from the viewpoint of producing a CNT collective wire. The upper limit value of the length of the carbon nanotube is not particularly limited, but from the viewpoint of production, it is preferably 600 mm or less. The length of the CNT can be measured by observing with a scanning electron microscope.

[0042] The diameter of the carbon nanotube is preferably 0.4 nm or more and 20 nm or less, and more preferably 1 nm or more and 10 nm or less. In particular, when the diameter of the carbon nanotube is 1 nm or more and 10 nm or less, it is suitable from the viewpoints of high density and high adhesion.

[0043] In this specification, the diameter of the carbon nanotube means the average outer diameter of one CNT. The average outer diameter of the CNT is obtained by directly observing cross-sections at any two locations of the CNT with a transmission electron microscope, measuring the outer diameter, which is the distance between the two farthest points on the outer periphery of the CNT in the cross-section, and calculating the average value of the obtained outer diameters. When the CNT includes a cone portion at one or both ends, the diameter is measured at a location excluding the cone portion.

[0044] <Second Step> Next, a second step is performed in which a plurality of carbon nanotubes obtained in the first step are aggregated to obtain a plurality of carbon nanotube collective wires (hereinafter, also referred to as "CNT collective wires"). The second step includes a second A step and a second B step. The second A step and the second B step will be described below.

[0045] <Second A Step> Step 2A is a step in which a first carbon nanotube group 11, which is composed of a portion of the multiple carbon nanotubes 1 obtained in Step 1, is assembled in the first channel 41 in an orientation along the longitudinal direction of the carbon nanotubes to obtain a first carbon nanotube assembly line 31. Multiple CNTs 1 synthesized in the CNT synthesis furnace 60 enter the first channel 41 with their longitudinal direction aligned with the flow of carbon-containing gas. The first channel 41 is arranged so that its longitudinal direction is aligned with the flow of carbon-containing gas. The cross-sectional area of ​​the first channel 41 normalized to the flow of carbon-containing gas is smaller than the cross-sectional area of ​​the CNT synthesis furnace 60 normalized to the flow of carbon-containing gas. Therefore, the multiple CNTs 1 that enter the first channel 41 assemble in the first channel 41 in an orientation along the longitudinal direction of the CNTs to form a first CNT assembly line 31.

[0046] <2B process> Step 2B is a step in which a second carbon nanotube group 12, which is composed of a portion of multiple carbon nanotubes different from the multiple carbon nanotubes that make up the first carbon nanotube group 11 obtained in Step 1, is assembled in the second channel 42 in an orientation along the longitudinal direction of the carbon nanotubes to obtain a second carbon nanotube assembly line 32. Multiple CNTs 1 synthesized in the CNT synthesis furnace 60 enter the second channel 42 with their longitudinal direction aligned with the flow of carbon-containing gas. The second channel 42 is arranged so that its longitudinal direction is aligned with the flow of carbon-containing gas. The cross-sectional area of ​​the second channel 42 normalized to the flow of carbon-containing gas is smaller than the cross-sectional area of ​​the CNT synthesis furnace 60 normalized to the flow of carbon-containing gas. Therefore, the multiple CNTs 1 that enter the second channel 42 assemble in the second channel 42 in an orientation along the longitudinal direction of the CNTs to form a second CNT assembly line 32.

[0047] In the method for manufacturing CNT bundles of this embodiment, a portion of multiple CNTs synthesized in one CNT synthesis furnace is oriented and assembled in a first channel to produce a first CNT bundle 31, and another portion of the multiple CNTs is oriented and assembled in a second channel to produce a second CNT bundle 32. In other words, in the method for manufacturing CNT bundles of this embodiment, two CNT bundles can be manufactured using one CNT synthesis furnace. In this embodiment, the second step includes two steps, 2A and 2B, and the case of obtaining two CNT bundles is shown, but the form of the second step is not limited to this. The number of CNT bundles obtained can be increased by increasing the number of channels in parallel in the second step. The number of channels corresponds to the number of CNT bundles obtained. Therefore, if the number of channels is 3, 3 CNT bundles can be obtained, and if the number of channels is 4, 4 CNT bundles can be obtained.

[0048] The number of carbon nanotubes constituting each of the first carbon nanotube group 11 and the second carbon nanotube group 12 (hereinafter also referred to as "carbon nanotube group") is adjusted according to the length and diameter of the carbon nanotube bundle formed from each carbon nanotube group.

[0049] The shape of the carbon nanotube bundle obtained in the second step is a thread-like shape in which multiple carbon nanotubes are bundled together, oriented in their longitudinal directions.

[0050] The length of the carbon nanotube bundle is not particularly limited and can be adjusted as appropriate depending on the application. The lower limit of the CNT bundle length is preferably 100 μm or more, more preferably 1000 μm or more, and even more preferably 10 cm or more. The upper limit of the CNT bundle length is not particularly limited, but from a manufacturing standpoint, it can be 100 km or less. The length of the CNT bundle is preferably 100 μm or more and 100 km or less, more preferably 1000 μm or more and 10 km or less, and even more preferably 10 cm or more and 1 km or less. The length of the CNT bundle is measured by scanning electron microscopy, optical microscope, or visual observation.

[0051] The diameter of the carbon nanotube bundle is not particularly limited and can be adjusted as appropriate depending on the application. The lower limit of the diameter of the CNT bundle is preferably 1 μm or more, more preferably 10 μm or more, even more preferably greater than 100 μm, and even more preferably 1000 μm or more. The upper limit of the diameter of the CNT bundle is not particularly limited, but from a manufacturing standpoint, it can be 10000 μm or less. The diameter of the CNT bundle is preferably 1 μm or more and 10000 μm or less, more preferably 10 μm or more and 1000 μm or less, even more preferably greater than 100 μm and 1000 μm or less, and even more preferably 300 μm or more and 1000 μm or less. In this embodiment, the diameter of the CNT bundle is smaller than the length of the CNT bundle. That is, the length direction of the CNT bundle corresponds to the longitudinal direction.

[0052] In this specification, the diameter of a carbon nanotube bundle refers to the average outer diameter of a single CNT bundle. The average outer diameter of a single CNT bundle is obtained by observing the cross-section of a single CNT bundle at any two locations using a transmission electron microscope, scanning electron microscope, or optical microscope, measuring the outer diameter which is the distance between the two furthest points on the outer circumference of the CNT bundle in the cross-section, and calculating the average value of the obtained outer diameters.

[0053] In the CNT bundle line obtained in this embodiment, it can be confirmed that multiple CNTs are bundled together oriented in their longitudinal direction by the following procedure (a1) to (a6).

[0054] (a1) Imaging of CNT cluster lines The following equipment will be used to image the carbon nanotube cluster lines under the following conditions.

[0055] Transmission electron microscope (TEM): JEOL "JEM2100" (product name) Imaging conditions: Magnification 50,000x to 1,200,000x, acceleration voltage 60kV to 200kV.

[0056] (a2) Binarization of captured images The image captured in (a1) above is subjected to binarization using the following image processing program, following the procedure below.

[0057] Image processing program: Non-destructive paper surface fiber orientation analysis program "FiberOri8single03" (http: / / www.enomae.com / FiberOri / index.htm) Processing procedure: 1. Histogram average brightness correction 2. Background removal 3. Binarization using a single threshold 4. Brightness inversion.

[0058] (a3) Fourier transform of the binarized image A Fourier transform is performed on the image obtained in (a2) above using the same image processing program as above (non-destructive paper surface fiber orientation analysis program "FiberOri8single03" (http: / / www.enomae.com / FiberOri / index.htm)).

[0059] (a4) Calculation of orientation angle and orientation intensity Using the Fourier transform image, calculate the average amplitude for counterclockwise angles (θ°), with the positive X-axis direction set to 0°. Graph the relationship between the orientation angle and orientation intensity obtained from the Fourier transform image.

[0060] (a5) Measurement of full width at half maximum Based on the graph above, the full width at half maximum (FWHM) is measured.

[0061] (a6) Calculation of the degree of orientation Based on the above full width at half maximum, the degree of orientation is calculated using the following formula (1).

[0062] Orientation degree=(180°-full width at half maximum) / 180° (1) A degree of orientation of 0 means completely unoriented. A degree of orientation of 1 means completely oriented. In this specification, if the degree of orientation is 0.8 or more and 1.0 or less, it is determined that multiple CNTs are oriented in their longitudinal directions and aggregated in a CNT aggregation line.

[0063] When the degree of orientation of carbon nanotubes in a carbon nanotube bundle is between 0.8 and 1.0, the CNT bundle is made longer while maintaining the electrical conductivity and mechanical strength properties of the CNTs.

[0064] Furthermore, as far as the applicant's measurements go, it was confirmed that there is almost no variation in the measurement results when calculating the degree of orientation multiple times by changing the selected measurement area (size: 10 nm × 10 nm) on the same sample.

[0065] <Other processes> The method for manufacturing CNT bundles in this embodiment preferably includes, after the second step, a third step of attaching a volatile liquid to a plurality of carbon nanotube bundles, and a fourth step of evaporating the volatile liquid attached to the carbon nanotube bundles. This allows the carbon nanotubes to adhere to each other uniformly and at high density as the liquid that has penetrated between the carbon nanotubes evaporates.

[0066] Examples of volatile liquids that can be used include methanol, ethanol, isopropyl alcohol, acetone, methyl ethyl ketone, xylene, anisole, toluene, cresol, pyrrolidone, carbitol, carbitol acetate, water, epoxy monomer, acrylic monomer, chlorosulfonic acid, nitric acid, and sulfuric acid. The volatile liquid may also contain monomers, resins, or acids.

[0067] The third step can be carried out, for example, by atomizing a volatile liquid into vapor using a liquid deposition device 63, and spraying the vapor onto the CNT assembly line. The fourth step can be carried out by natural drying.

[0068] The third and fourth steps are preferably carried out while applying tension to the carbon nanotube bundle by winding it with the winding device 64. This improves the strength of the resulting CNT bundle.

[0069] [Embodiment 2: Carbon nanotube bundled wire manufacturing apparatus (1)] An example of a carbon nanotube bundle manufacturing apparatus used in the carbon nanotube bundle manufacturing method according to Embodiment 1 will be explained with reference to Figure 2.

[0070] As shown in Figure 2, the carbon nanotube bundle wire manufacturing apparatus 100a of this embodiment comprises a tubular carbon nanotube synthesis furnace 60, a carbon-containing gas supply port 62 provided at one end of the carbon nanotube synthesis furnace 60 (left side in Figure 2), and a first channel 41 and a second channel 42 provided at the end of the carbon nanotube synthesis furnace 60 opposite to the end where the carbon-containing gas supply port 62 is provided (right side in Figure 2). The first channel 41 and the second channel 42 are provided in parallel along the longitudinal direction of the carbon nanotube synthesis furnace 60, and the cross-sectional area of ​​the first channel 41 and the second channel 42 is smaller than the cross-sectional area of ​​the carbon nanotube synthesis furnace 60.

[0071] <Carbon nanotube synthesis furnace> The carbon nanotube synthesis furnace (hereinafter also referred to as the "CNT synthesis furnace") 60 has a tubular shape, for example, made of a quartz tube. In the CNT synthesis furnace 60, carbon nanotubes 1 are formed on catalyst particles 27 using a carbon-containing gas.

[0072] The carbon nanotube synthesis furnace 60 is heated by a heating device 61. The internal temperature of the CNT synthesis furnace 60 during heating is preferably 800°C to 1500°C, more preferably 900°C to 1400°C, and even more preferably 1000°C to 1200°C. To maintain such a temperature, heated carbon-containing gas may be supplied to the CNT synthesis furnace 60 from the carbon-containing gas supply port 62, or the carbon-containing gas may be heated in the CNT synthesis furnace 60.

[0073] The diameter (Φ) of the cross-section of the carbon nanotube synthesis furnace 60 is preferably Φ30 mm or more, more preferably Φ100 mm or more, and even more preferably Φ300 mm or more, from the viewpoint of ensuring a sufficient amount of carbon nanotubes synthesized. The upper limit of the cross-sectional area of ​​the carbon nanotube synthesis furnace 60 is not particularly limited, but from the viewpoint of apparatus design, it can be Φ1 m or less. The cross-sectional area of ​​the carbon nanotube synthesis furnace 60 is preferably Φ30 mm or more and Φ1 m or less, more preferably Φ50 mm or more and Φ500 mm or less, and even more preferably Φ100 mm or more and Φ200 mm or less. In this specification, the diameter of the cross-section of the CNT synthesis furnace 60 means the diameter of the circular hollow portion of the CNT synthesis furnace in a cross-section normalized to the longitudinal direction (centerline) of the CNT synthesis furnace.

[0074] <Carbon-containing gas supply port> The carbon-containing gas supply port 62 is located at one end of the carbon nanotube synthesis furnace 60 (the left end in Figure 2), and the carbon-containing gas is supplied to the CNT synthesis furnace 60 from the carbon-containing gas supply port 62. A catalyst (not shown) is placed near the carbon-containing gas supply port inside the CNT synthesis furnace 60.

[0075] The carbon-containing gas supply port 62 can be configured to include a gas cylinder (not shown) and a flow control valve (not shown).

[0076] <First channel and second channel> The first channel 41 and the second channel 42 are provided on the end of the carbon nanotube synthesis furnace 60 opposite to the end where the carbon-containing gas supply port 62 is located. The first channel 41 is provided in the first A structure 40A. The second channel 42 is provided in the first B structure 40B.

[0077] The first A structure 40A consists of a tubular first A-1 section 40A-1 and a funnel-shaped first A-2 section 40A-2 connected to the end of the first A-1 section 40A-1 on the carbon-containing gas supply port 62 side (left side in Figure 2). Here, the smaller diameter end of the first A-2 section 40A-2 is connected to the end of the first A-1 section 40A-1. Therefore, in the first A structure 40A, the larger diameter end of the first A-2 section 40A-2 faces the carbon-containing gas supply port 62. It is preferable that at least a part of the first A structure 40A is placed inside the CNT synthesis furnace 60. With the above configuration, CNTs are easily taken into the first flow path 41.

[0078] The first B structure 40B consists of a tubular first B-1 section 40B-1 and a funnel-shaped first B-2 section 40B-2 connected to the end of the first B-1 section 40B-1 on the carbon-containing gas supply port 62 side (left side in Figure 2). Here, the smaller diameter end of the first B-2 section 40B-2 is connected to the end of the first B-1 section 40B-1. Therefore, in the first B structure 40B, the larger diameter end of the first B-2 section 40B-2 faces the carbon-containing gas supply port 62. It is preferable that at least a part of the first B structure 40B is placed inside the CNT synthesis furnace 60. With the above configuration, CNTs are easily taken into the second flow path 42.

[0079] The first channel 41 and the second channel 42 are arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace 60, and the cross-sectional area of ​​each of the first channel 41 and the second channel 42 is smaller than the cross-sectional area of ​​the carbon nanotube synthesis furnace 60. With this configuration, multiple CNTs are oriented and aggregated along their longitudinal directions within each of the first channel 41 and the second channel 42, forming CNT aggregation lines.

[0080] In this specification, the first channel 41 and the second channel 42 being arranged in parallel along the longitudinal direction of the CNT synthesis furnace 60 means that the following conditions (i) and (ii) are met. (i) The angle between the longitudinal direction (centerline) of the CNT synthesis furnace 60 and the longitudinal direction (centerline) of the first channel 41 is 0° or more and 20° or less, and the angle between the longitudinal direction (centerline) of the CNT synthesis furnace 60 and the longitudinal direction (centerline) of the second channel 42 is 0° or more and 20° or less. (ii) The angle between the longitudinal direction (centerline) of the first channel 41 and the longitudinal direction (centerline) of the second channel 42 is 0° or more and 40° or less.

[0081] In this specification, the cross-sectional area of ​​the first channel 41 refers to the area of ​​the first channel in a cross-section normal to the longitudinal direction (centerline) of the first channel, and corresponds to the cross-sectional area of ​​the hollow portion of the first A structure. As shown in Figure 2, the first channel consists of a hollow portion of the first A structure 40A, which is composed of a tubular first A-1 section 40A-1 and a funnel-shaped first A-2 section 40A-2, and the cross-sectional area of ​​the hollow portion is not constant. In this case, "the cross-sectional area of ​​the first channel is smaller than the cross-sectional area of ​​the CNT synthesis furnace" means "the largest cross-sectional area of ​​the first channel is smaller than the cross-sectional area of ​​the hollow portion of the CNT synthesis furnace." In the first channel 41, the largest cross-sectional area of ​​the first channel corresponds to the cross-sectional area at the end of the first A-2 section 40A-2 closest to the carbon-containing gas supply port 62. The relationship between the cross-sectional area of ​​the second channel 42 and the cross-sectional area of ​​the CNT synthesis furnace 60 is defined in the same way as the relationship between the cross-sectional area of ​​the first channel 41 and the cross-sectional area of ​​the CNT synthesis furnace 60 described above.

[0082] The cross-sectional areas of the first channel 41 and the second channel 42 are smaller than the cross-sectional area of ​​the carbon nanotube synthesis furnace 60. This allows a tensile force to be applied to the CNTs in the first and second channels in the direction toward the downstream side of the carbon-containing gas. When a tensile force is applied to the ends of the carbon nanotubes, the carbon nanotubes extending from the catalyst particles 27 are pulled, undergoing plastic deformation and elongating in the longitudinal direction while decreasing in diameter. Therefore, the CNT cluster lines are easily oriented and lengthened.

[0083] The cross-sectional area of each of the first flow path 41 and the second flow path 42 can be appropriately set according to the desired diameter of the CNT collective wire. The lower limit of the cross-sectional area of each of the first flow path 41 and the second flow path 42 is 0.1 mm 2 or more, preferably 1 mm 2 or more, more preferably 10 mm 2 or more. The upper limit of the cross-sectional area of each of the first flow path 41 and the second flow path is preferably 300 mm 2 or less, more preferably 200 mm 2 or less, still more preferably 100 mm 2 or less.

[0084] In the present embodiment, two flow paths, the first flow path 41 and the second flow path 42, are provided in parallel on the end side of the CNT synthesis furnace. However, the number of flow paths is not limited to two and can be three or more. In the CNT collective wire manufacturing apparatus of the present embodiment, the number of flow paths provided in parallel corresponds to the number of CNT collective wires to be produced. Therefore, by increasing the number of flow paths provided in parallel, the number of CNT collective wires produced using one CNT synthesis furnace can be increased.

[0085] The cross-sectional area of the CNT synthesis furnace 60 is not particularly limited as long as it is large enough to provide the first flow path 41 and the second flow path 42 inside the CNT synthesis furnace. By appropriately adjusting the cross-sectional area of the CNT synthesis furnace 60 according to the number of flow paths and the cross-sectional area of the flow paths, a plurality of CNT collective wires can be produced from one CNT synthesis furnace.

[0086] The lower limit of the cross-sectional area of the CNT synthesis furnace is, for example, 500 mm 2 or more, preferably 5000 mm 2 or more, more preferably 50000 mm 2 or more, from the viewpoint of improving the manufacturing efficiency of the CNT collective wire. The upper limit of the cross-sectional area of the CNT synthesis furnace is not particularly limited, but from the viewpoint of manufacturing equipment, for example, it can be 1 m 2 or less. The cross-sectional area of the CNT synthesis furnace is 500 mm 2 or more and 1 m 2The following is preferable: 5000mm 2 Over 50,000 mm 2 The following is more preferable: 10,000 mm 2 Above 20,000 mm 2 The following is even more preferable.

[0087] It is preferable that the 1A structure and the 1B structure have the same shape. This ensures that the shape of the CNT bundle lines recovered from each structure is nearly uniform.

[0088] <Other configurations> The CNT bundled wire manufacturing apparatus of this embodiment preferably includes a liquid deposition apparatus 63 for depositing a volatile liquid onto the carbon nanotube bundled wires 31 and 32. Details of the volatile liquid are described in Embodiment 1, so that description will not be repeated.

[0089] The liquid deposition device 63 is positioned to deposit a volatile liquid onto the carbon nanotube bundle lines 31 and 32. For example, as shown in Figure 2, the liquid deposition device 63 can be positioned downstream of the carbon-containing gas from the first channel 41 and the second channel 42.

[0090] The CNT bundle wire manufacturing apparatus of this embodiment preferably includes a winding device 64 that winds the carbon nanotube bundle wires 31 and 32 while applying tension to them. By winding the CNT bundle wires while applying tension and stretching them, it is possible to obtain CNT bundle wires with high strength.

[0091] [Embodiment 3: Method for manufacturing carbon nanotube bundles (2)] The method for manufacturing carbon nanotube bundles according to this embodiment will be explained with reference to Figures 3 to 6. Figure 3 is a flowchart of the method for manufacturing carbon nanotube bundles according to this embodiment. Figure 4 is a diagram showing an example of a carbon nanotube bundle manufacturing apparatus used in the method for manufacturing carbon nanotube bundles according to this embodiment. Figure 5 is a diagram showing the main surface of the 1-1 structure provided in the CNT bundle manufacturing apparatus of Figure 4 on the carbon-containing gas supply port 62 side. Figure 6 is a cross-sectional view of the first channel and the second channel provided in the CNT bundle manufacturing apparatus of Figure 4, in the direction along the longitudinal direction of the CNT synthesis furnace.

[0092] As shown in Figures 3 to 6, the method for manufacturing a CNT bundle of wires in this embodiment is the same as the method for manufacturing a CNT bundle of wires in Embodiment 1 described above. The above-mentioned first carbon nanotube group 11 includes a first A carbon nanotube group 11A, which is composed of a portion of a plurality of carbon nanotubes constituting the first carbon nanotube group 11, and a first a carbon nanotube group 11a, which is composed of a portion of a plurality of carbon nanotubes constituting the first carbon nanotube group 11 that are different from the plurality of carbon nanotubes constituting the first A carbon nanotube group 11A. The first channel described above includes a first-1A channel 41A and a first-1a channel 41a arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace, and a first-2 channel 41C provided downstream of the carbon-containing gas flow in the first-1A channel 41A and the first-1a channel 41a. The second A step is, The second A-1A step involves assembling the first A carbon nanotube group 11A in the first-1A channel 41A in an orientation along the longitudinal direction of the carbon nanotubes to obtain the first A carbon nanotube bundle wire 21A, Step 2A-1a involves assembling the first a carbon nanotube group 11a in the first-1a channel 41a in an orientation along the longitudinal direction of the carbon nanotubes to obtain the first a carbon nanotube bundle wire 21a, The process includes a second A-2 step of assembling a plurality of carbon nanotube bundle wires, including the first A carbon nanotube bundle wire 21A and the first a carbon nanotube bundle wire 21a, in the first-second channel 41C, oriented along the longitudinal direction of the carbon nanotube bundle wires, to obtain a first carbon nanotube bundle wire 31. The above-mentioned second carbon nanotube group 12 includes a second B carbon nanotube group 12B, which is composed of a portion of the plurality of carbon nanotubes constituting the above-mentioned second carbon nanotube group, and a second b carbon nanotube group 12b, which is composed of a portion of the plurality of carbon nanotubes constituting the above-mentioned second carbon nanotube group 12, which are different from the plurality of carbon nanotubes constituting the second B carbon nanotube group 12B. The second channel described above includes a second-1B channel 42B and a second-1b channel 42b arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace, and a second-2 channel 42D provided downstream of the carbon-containing gas flow in the second-1B channel 42B and the second-1b channel 42b. The above-mentioned second B step is, The second B-1B step involves assembling the second B carbon nanotube group 12B in the second B channel 42B in an orientation along the longitudinal direction of the carbon nanotubes to obtain the second B carbon nanotube bundle wire 22B, The second B-1b step involves assembling the second b carbon nanotube group 12b in the second B channel 42b in an orientation along the longitudinal direction of the carbon nanotubes to obtain the second b carbon nanotube bundle wire 22b, The method may include a second B-2 step in which a plurality of carbon nanotube bundles, including the second B carbon nanotube bundle 22B and the second b carbon nanotube bundle 22b, are assembled in the second-2 channel 42D in an orientation along the longitudinal direction of the carbon nanotube bundles to obtain a second carbon nanotube bundle 32. It is preferable that the plurality of carbon nanotubes constituting the first carbon nanotube group 11 are in a separated state without forming a network that inhibits separation before entering the first channel 41. It is preferable that the plurality of carbon nanotubes constituting the second carbon nanotube group 12 are in a separated state without forming a network that inhibits separation before entering the second channel 42. This makes it possible to prevent clogging of the plurality of carbon nanotubes near the entrance of the first channel and near the entrance of the second channel.

[0093] In this specification, the 1-1A channel, the 1-1a channel, the 2-1B channel, and the 2-1b channel are also referred to as "upstream channels." The 1-2 channel and the 2-2 channel are also referred to as "downstream channels."

[0094] In the method for manufacturing CNT bundles of this embodiment, two CNT bundles can be manufactured using one CNT synthesis furnace. In this embodiment, the second step includes two steps, 2A and 2B, and the case where two CNT bundles are obtained is shown, but the form of the second step is not limited to this. The number of CNT bundles obtained can be increased by increasing in parallel the number of channels located downstream of the carbon-containing gas (downstream channels, corresponding to the 1st-2nd channels 41C and 2nd-2nd channels 42D in Figure 4). The number of downstream channels is equal to the number of CNT bundles obtained. Therefore, if the number of downstream channels is 3, 3 CNT bundles can be obtained, and if the number of downstream channels is 4, 4 CNT bundles can be obtained.

[0095] The method for manufacturing carbon nanotube bundles of wire according to this embodiment basically comprises all the steps of the method for manufacturing CNT bundles of wire according to Embodiment 1. The difference from the method for manufacturing CNT bundles of wire according to Embodiment 1 is that Step 2A and Step 2B each comprise a step of obtaining a plurality of carbon nanotube bundle wires (hereinafter also referred to as "CNT bundle wires") (Step 2A-1A, Step 2A-1a, Step 2B-1B, Step 2B-1b), and a step of aligning and bundling the plurality of CNT bundle wires along their longitudinal directions to obtain a CNT bundle (Step 2A-2, Step 2B-2). Accordingly, Steps 2A-1A, 2A-1a, 2A-2, 2B-1B, 2B-1b, and 2B-2 will be described below.

[0096] <2A-1A process, 2A-1a process, 2B-1B process, 2B-1b process> Steps 2A-1A, 2A-1a, 2B-1B, and 2B-1b are processes that involve assembling a group of carbon nanotubes, each consisting of multiple carbon nanotubes, in an upstream channel, oriented along the longitudinal direction of the carbon nanotubes, to obtain a carbon nanotube bundle wire. As a representative of these processes, Step 2A-1 will be described below.

[0097] In step 2A-1, the 1A carbon nanotube group 11A, consisting of multiple CNTs synthesized in the CNT synthesis furnace 60, enters the 1-1A channel 41A with the longitudinal direction of the CNTs aligned with the flow of carbon-containing gas. The 1-1A channel 41A is positioned so that its longitudinal direction aligns with the flow of carbon-containing gas. The cross-sectional area of ​​the 1-1A channel 41A normalized to the flow of carbon-containing gas is smaller than the cross-sectional area of ​​the CNT synthesis furnace 60 normalized to the flow of carbon-containing gas. Therefore, the multiple CNTs that enter the 1-1A channel 41A align and aggregate within the 1-1A channel 41A along the longitudinal direction of the CNTs to form the 1A carbon nanotube aggregate wire 21A.

[0098] The lower limit of the number of carbon nanotubes constituting the 1A carbon nanotube group is 1000, from the viewpoint of increasing the length of the carbon nanotube bundle strand. From the book The above is preferable, more preferably 1 million or more, and even more preferably 100 million or more. From the viewpoint of preventing clogging of the flow channel, the upper limit of the number of carbon nanotubes constituting the 1A carbon nanotube group is preferably 1 trillion or less, more preferably 10 billion or less, and even more preferably 1 billion or less. The number of carbon nanotubes constituting the 1A carbon nanotube group is preferably 10,000 to 1 billion, more preferably 100,000 to 100 million, and even more preferably 1 million to 100 million. Here, the number of carbon nanotubes constituting the 1A carbon nanotube group means the number of carbon nanotubes that simultaneously pass through the opening on the carbon-containing gas supply port side of the 1-1A flow channel 41A.

[0099] The shape of the 1A carbon nanotube aggregate wire 21A obtained by the 2A-1A process is a thread-like shape in which multiple carbon nanotubes are aggregated and oriented in their longitudinal directions.

[0100] The length of the carbon nanotube bundle wire (hereinafter also referred to as "CNT bundle wire") is not particularly limited as long as it is long enough to form a carbon nanotube bundle wire in the following step 2A-2.

[0101] The diameter of the carbon nanotube bundle wire is not particularly limited and can be adjusted as appropriate depending on the application. The lower limit of the diameter of the CNT bundle wire is preferably 0.1 μm or more, and more preferably 1 μm or more. The upper limit of the diameter of the CNT bundle wire is not particularly limited, but from a manufacturing standpoint, it can be 100 μm or less. The diameter of the CNT bundle wire is preferably 0.1 μm or more and 100 μm or less, and more preferably 1 μm or more and 100 μm or less. In this embodiment, the diameter of the CNT bundle wire is smaller than the length of the CNT bundle wire. That is, the length direction of the CNT bundle wire corresponds to the longitudinal direction.

[0102] In this specification, the diameter of a carbon nanotube bundle wire refers to the average outer diameter of a single CNT bundle wire. The average outer diameter of a single CNT bundle wire is obtained by observing the cross-section of a single CNT bundle wire at any two locations using a transmission electron microscope or scanning electron microscope, measuring the outer diameter which is the distance between the two furthest points on the outer circumference of the CNT bundle wire in the cross-section, and calculating the average value of the obtained outer diameters.

[0103] In the CNT bundled wire obtained in this embodiment, the fact that multiple CNTs are oriented in their longitudinal direction can be confirmed in the same way as the method for confirming "that multiple CNTs are oriented in their longitudinal direction in the CNT bundled wire" described in Embodiment 1, so that explanation will not be repeated.

[0104] The orientation degree of the carbon nanotubes (CNTs) in the carbon nanotube bundle wire is preferably between 0.8 and 1.0. The CNT bundle wire is made longer while maintaining the electrical conductivity and mechanical strength properties of the CNTs.

[0105] Processes 2A-1a, 2B-1B, and 2B-1b are essentially the same as process 2A-1 and will not be explained again.

[0106] <2A-2 process, 2B-2 process> Steps 2A-2 and 2B-2 are processes that align and assemble multiple CNT bundle wires along the longitudinal direction of the carbon nanotube bundle wire in the downstream channel to obtain a carbon nanotube bundle wire. As a representative of these processes, Step 2A-2 will be described below.

[0107] In step 2A-2, multiple carbon nanotube bundled wires, including the 1A carbon nanotube bundled wire 21A obtained in step 2A-1A and the 1a carbon nanotube bundled wire 21a obtained in step 2A-1a, enter the 1-2 channel 41C with the longitudinal direction of the CNT bundled wires aligned with the flow of carbon-containing gas. The 1-2 channel 41C is positioned so that its longitudinal direction aligns with the flow of carbon-containing gas. The multiple CNT bundled wires that enter the 1-2 channel 41C align and aggregate within the 1-2 channel 41C along the longitudinal direction of the CNT bundled wires to form the 1st carbon nanotube bundled wire 31.

[0108] By providing a downstream channel (channel 1-2 41C), multiple carbon nanotube bundle wires exiting from the upstream channels (channel 1-1A, channel 1-1a) can not become entangled in an unoriented state, but instead align longitudinally and bundle together within the downstream channel to form a carbon nanotube bundle wire.

[0109] The lower limit of the number of carbon nanotube bundle wires constituting the first carbon nanotube bundle wire is preferably 2 or more, more preferably 10 or more, and even more preferably 100 or more, from the viewpoint of lengthening the carbon nanotube bundle wire. The upper limit of the number of carbon nanotube bundle wires constituting the first carbon nanotube bundle wire is preferably 10,000 or less, more preferably 1,000 or less, and even more preferably 300 or less, from the viewpoint of preventing clogging of the flow channel. The number of carbon nanotube bundle wires constituting the first carbon nanotube bundle wire is preferably 2 or more and 10,000 or less, more preferably 10 or more and 1,000 or less, and even more preferably 100 or more and 300 or less. Here, the number of carbon nanotube bundle wires constituting the first carbon nanotube bundle wire means the number of carbon nanotube bundle wires that simultaneously pass through the opening on the carbon-containing gas supply port side of the first-to-second flow channel 41C.

[0110] The shape of a carbon nanotube bundle is a string-like structure formed by multiple carbon nanotube bundles oriented in their longitudinal directions. This string-like structure of a CNT bundle can be confirmed by observation with an optical microscope or a scanning electron microscope.

[0111] The length of the carbon nanotube bundle obtained in this embodiment is not particularly limited and can be adjusted as appropriate depending on the application. The lower limit of the CNT bundle length is preferably 100 μm or more, more preferably 1000 μm or more, and even more preferably 10 cm or more. The upper limit of the CNT bundle length is not particularly limited, but from a manufacturing standpoint, 100 km or less is preferred. The length of the CNT bundle is preferably 100 μm or more and 10 km or less, more preferably 1000 μm or more and 1 km or less, and even more preferably 10 cm or more and 100 m or less. The length of the CNT bundle can be measured by observation with an optical microscope or by visual inspection.

[0112] The diameter of the carbon nanotube bundle obtained in this embodiment is not particularly limited and can be adjusted as appropriate depending on the application. The diameter of the CNT bundle is preferably 1 μm or more, and more preferably 10 μm or more. There is no particular upper limit to the diameter of the CNT bundle, but from a manufacturing standpoint, it is preferably 10,000 μm or less. In this embodiment, the diameter of the CNT bundle is smaller than the length of the CNT bundle.

[0113] The degree of orientation of the CNT bundle strands in a carbon nanotube bundle line is basically the same as the procedure (a1) to (a6) described in the method for calculating the degree of orientation in Embodiment 1. The difference is that in procedure (a1), the CNT bundle line is imaged using the following equipment under the following conditions.

[0114] Scanning Electron Microscope (SEM): "Cry-10" (product name) manufactured by Technex Kobo Co., Ltd. Imaging conditions: Magnification 40x to 100,000x, acceleration voltage 1kV to 17kV V . Measurement field of view: 30 μm × 30 μm

[0115] The above measurements are performed in 10 or more arbitrarily selected measurement fields. If, in one or more of the measurement fields, the degree of orientation of the carbon nanotube bundle wires in the carbon nanotube bundle line is between 0.8 and 1, it is determined that the carbon nanotube bundle wires in that carbon nanotube bundle line are oriented and bundled in their longitudinal direction.

[0116] In the carbon nanotube bundle wire according to this embodiment, it is preferable that the carbon nanotubes in the carbon nanotube bundle wire are oriented with an orientation degree of 0.9 to 1, and that the carbon nanotube bundle wires are oriented with an orientation degree of 0.8 to 1. This means that the orientation of the CNT bundle wire and the CNT bundle wire is high. As a result, the CNT bundle wire can have excellent electrical conductivity and mechanical strength.

[0117] [Embodiment 4 :Carbon nanotube bundled wire manufacturing apparatus (2)] Embodiment 3 The carbon nanotube bundle manufacturing apparatus used in the method for manufacturing carbon nanotube bundles will be explained with reference to Figures 4 to 6.

[0118] The carbon nanotube bundled wire manufacturing apparatus 100b of this embodiment basically has all the components of the carbon nanotube bundled wire manufacturing apparatus of Embodiment 2. The difference from the CNT bundled wire manufacturing apparatus of Embodiment 2 is that, as shown in Figures 4 and 6, the first channel includes the 1-1A channel 41A and the 1-1a channel 41a, which are provided in parallel on the carbon-containing gas supply port 62 side of the carbon nanotube synthesis furnace 60, and the 1-2 channel 41C, which is provided on the opposite side of the 1-1A channel 41A and the 1-1a channel 41a from the carbon-containing gas supply port 62, and the second channel includes the 2-1B channel 42B and the 2-1b channel 42b, which are provided in parallel on the carbon-containing gas supply port side of the carbon nanotube synthesis furnace 60, and the 2-2 channel 42D, which is provided on the opposite side of the 2-1B channel 42B and the 2-1b channel 42b from the carbon-containing gas supply port 62. The following describes the differences between this embodiment and the CNT bundled wire manufacturing apparatus of Embodiment 2.

[0119] In this embodiment, as shown in Figure 6, the 1-1A channel 41A, the 1-1a channel 41a, the 2-1B channel 42B, and the 2-1b channel 42b are provided in the same 1-1 structure 51, the 1-2 channel 41C is provided in a 1-2 structure 52A different from the 1-1 structure 51, and the 2-2 channel 42D is provided in a 2-2 structure 52B different from the 1-1 structure 51.

[0120] <1st-1st structure> The first-first structure 51 is a porous body having numerous narrow, cylindrical through-holes. Each through-hole corresponds to a flow path. The first-first structure 51 has through-holes corresponding to the first-firstA flow path 41A, the first-firsta flow path 41a, the second-firstB flow path 42B, and the second-firstb flow path 42b.

[0121] The cross-sectional shape of each through-hole can be, for example, circular or a regular polygon (e.g., a regular n-gon with n=3 to 10). From the viewpoint of suppressing the deposition of CNTs within the through-holes and ensuring the strength of the 1-1 structure, the cross-sectional shape of each through-hole is preferably a regular hexagon.

[0122] The cross-sectional area of ​​each through-hole can be appropriately changed depending on the desired diameter and length of the CNT bundle. The lower limit of the cross-sectional area of ​​each through-hole is 0.005 mm, from the viewpoint of preventing clogging of the CNTs. 2 The above is preferable, 0.01 mm 2 The above is preferable, 0.05 mm 2 The above is preferable, 0.1 mm 2 The above is more preferable, 0.5 mm 2 The above is even more preferable. The upper limit of the cross-sectional area of ​​each through-hole is, from the viewpoint of the ease with which CNTs aggregate, for example, 100 mm. 2 The following is preferable: 50 mm 2 The following is more preferable: 10 mm 2 The following is even more preferable. In this specification, the cross-sectional area of ​​each through-hole means the area of ​​the cross section normal to the longitudinal direction of the hollow portion surrounded by the 1-1 structure that forms the outer edge of the through-hole. It is preferable that the cross-sectional area of ​​each through-hole is constant from the upstream side to the downstream side. Here, a constant cross-sectional area means that the maximum and minimum values ​​of the cross-sectional area are within ±5% of the average value.

[0123] The lower limit of the length of the through-hole in the longitudinal direction (the direction along the flow of carbon-containing gas) is preferably 5 mm or more, more preferably 10 mm or more, and even more preferably 30 mm or more, from the viewpoint of sufficient aggregation of CNTs. The upper limit of the length of the through-hole in the longitudinal direction is preferably 1000 mm or less, more preferably 300 mm or less, and even more preferably 100 mm or less, from the viewpoint of suppressing the deposition of CNTs on the inner wall of the through-hole and increasing the amount of CNT aggregated strands recovered. The length of the through-hole in the longitudinal direction is preferably 5 mm or more and 1000 mm or less, more preferably 10 mm or more and 30 mm or more and even more preferably 100 mm or more.

[0124] The number of through-holes provided in the 1-1 structure can be appropriately set considering the cross-sectional area of ​​the hollow part of the CNT synthesis furnace, the cross-sectional area of ​​each through-hole, the desired number of CNT bundled strands, etc. For example, the lower limit of the number of through-holes provided in the 1-1 structure can be set to 1 per 10 cm from the viewpoint of improving manufacturing efficiency. 2 The above is preferable, 1 piece / cm 2 The above is more preferable, 1 piece / mm2 The above is even more preferable. The upper limit of the number of through holes provided in the 1-1 structure is not particularly limited, for example, 100 holes / mm 2 The following is possible: The number of through holes provided in the 1-1 structure is 1 per 10 cm. 2 More than 100 pieces / mm 2 The following is preferable: 1 piece / cm 2 More than 100 pieces / mm 2 The following is more preferable: 1 piece / mm 2 More than 10 pieces / mm 2 The following is even more preferable.

[0125] The cross-sectional area of ​​the 1-1 structure is not limited and can be set according to the cross-sectional area of ​​the hollow part of the CNT synthesis furnace. Here, the cross-sectional area of ​​the 1-1 structure refers to the area of ​​the region surrounded by the outer edge of the 1-1 structure, and includes the area of ​​through holes. The lower limit of the cross-sectional area of ​​the 1-1 structure is 100 mm from the viewpoint of improving the manufacturing efficiency of CNT bundles. 2 The above is preferable, 1000mm 2 More preferably, 10,000 mm 2 The above is even more preferable. The upper limit of the cross-sectional area of ​​the 1-1 structure is not particularly limited, but from the viewpoint of manufacturing equipment, for example, 1 m 2 The following is possible: The cross-sectional area of ​​the 1-1 structure is 100 mm². 2 1 meter or more 2 The following is preferable, 1000mm 2 More than 0.3m 2 The following is more preferable: 10,000 mm 2 Above 0.1m 2 The following is even more preferable.

[0126] The 1-1 structure can consist of ceramics (alumina, zirconia, aluminum nitride, silicon carbide, silicon nitride, forsterite, steatite, cordierite, mullite, ferrite, gadolinium oxide, etc.), quartz glass, glass, metals, and graphite. Among these, it is preferable to use ceramics from the viewpoint of heat resistance and durability required during CNT manufacturing. Furthermore, it is preferable to form arbitrary channels using 3D printing technology.

[0127] <1st-2nd structure, 2nd-2nd structure> Since the 1-2 structure 52A and 2-2 structure 52B can be basically configured similarly to the 1A structure and 1B structure of Embodiment 2, their description will not be repeated.

[0128] [Embodiment 5: Carbon nanotube bundled wire manufacturing apparatus (3)] The carbon nanotube bundled wire manufacturing apparatus of Embodiment 5 is another example of a manufacturing apparatus used in the carbon nanotube bundled wire manufacturing method of Embodiment 3. The carbon nanotube bundled wire manufacturing apparatus of Embodiment 5 will be described with reference to Figures 7 to 10. Figure 7 is a diagram showing an example of a carbon nanotube bundled wire manufacturing apparatus used in the carbon nanotube bundled wire manufacturing method of this embodiment. Figure 8 is a diagram showing the main surface of the first-third structure 53 provided in the CNT bundled wire manufacturing apparatus of Figure 7 on the carbon-containing gas supply port 62 side. Figure 9 is a diagram showing the main surface of the first-third structure 53 provided in the CNT bundled wire manufacturing apparatus of Figure 7 on the side opposite to the main surface of the carbon-containing gas supply port 62 side. Figure 10 is a cross-sectional view of the first-third structure 53 provided in the CNT bundled wire manufacturing apparatus of Figure 7, in the direction along the longitudinal direction of the CNT synthesis furnace. The differences from the CNT bundled wire manufacturing apparatus of Embodiment 4 will be described below.

[0129] In this embodiment, as shown in Figure 10, the 1-1A channel 41A, 1-1a channel 41a, 1-2 channel 41C, 2-1B channel 42B, 2-1b channel 42b, and 2-2 channel 42D are provided in the same 1-3 structure 53. The ends of the 1-1A channel 41A and 1-1a channel 41a opposite to the carbon-containing gas supply port 62 are connected to the carbon-containing gas supply port 62 side end of the 1-2 channel 41C, and the ends of the 2-1B channel 42B and 2-1b channel 42b opposite to the carbon-containing gas supply port 62 are connected to the carbon-containing gas supply port 62 side end of the 2-2 channel 42D.

[0130] <1st-3rd structure> The first-third structure 53 is a porous body having numerous thin, cylindrical through-holes. These through-holes correspond to flow paths. The main surface of the first-third structure on the carbon-containing gas supply port 62 side is provided with a plurality of openings (hereinafter also referred to as "first openings"), including openings that form the ends of the first-firstA flow path 41A, the first-firsta flow path 41a, the second-firstB flow path 42B, and the second-firstb flow path 42b. The main surface of the first-third structure opposite to the main surface on the carbon-containing gas supply port 62 side is provided with a plurality of openings (hereinafter also referred to as "second openings"), including openings that form the ends of the first-second flow path 41C and the second-second flow path 42D.

[0131] Multiple CNTs that have entered the 1-1A channel 41A and the 1-1a channel 41a align longitudinally and assemble to form CNT bundle strands 21A and 21a. Subsequently, in the 1-2 channel 41C, multiple CNT bundle strands, including the CNT bundle strands 21A and 21a, align longitudinally and assemble to form a CNT bundle strand 31.

[0132] Multiple CNTs that have entered the 2-1B channel 42B and the 2-1b channel 42b align longitudinally and aggregate to form CNT aggregate wires 21B and 21b. Subsequently, in the 2-2 channel 41D, multiple CNT aggregate wires, including the CNT aggregate wires 21B and 21b, align longitudinally and aggregate to form a CNT aggregate wire 32.

[0133] As described above, in this embodiment, the formation of CNT bundled strands and CNT bundled lines is carried out continuously within the first-to-third structure 53. This improves the manufacturing efficiency of the CNT bundled lines.

[0134] The number of channels connected to the first-second channel 41C is not limited to the two channels, the first-first-a channel 41A and the first-first-a channel 41a, but can be appropriately set according to the desired length and diameter of the CNT bundle. The lower limit of the number of channels connected to the first-second channel 41C is preferably 2 or more, more preferably 5 or more, and even more preferably 10 or more, from the viewpoint of preventing turbulence due to turbulence, etc. The upper limit of the number of channels connected to the first-second channel 41C is not particularly limited, but can be 100 or less from the viewpoint of manufacturing the first-third structure. The number of channels connected to the first-second channel 41C is preferably 2 or more and 100 or less, more preferably 5 or more and 50 or less, and even more preferably 10 or more and 20 or less. The number of channels connected to the second-second channel 42D can be set in the same way as the number of channels connected to the first-second channel 41C.

[0135] The lower limit of the cross-sectional area of ​​the through-holes forming the 1-1A channel 41A, 1-1a channel 41a, 2-1B channel 42B, and 2-1b channel 42b is 0.005 mm, from the viewpoint of preventing clogging of CNTs. 2 The above is preferable, 0.01 mm 2 The above is preferable, 0.05 mm 2 The above is preferable, 0.1 mm 2 The above is more preferable, 0.5 mm 2 The above is even more preferable. The upper limit of the cross-sectional area of ​​each through-hole is, from the viewpoint of the ease with which CNTs aggregate, for example, 100 mm. 2 The following is preferable: 50 mm 2 The following is more preferable: 10 mm 2 The following is even more preferable. In this specification, the cross-sectional area of ​​each through-hole means the area of ​​the region surrounded by the 1st to 3rd structures that form the outer edge of the through-hole. It is preferable that the cross-sectional area of ​​each through-hole is constant from the upstream side to the downstream side. Here, a constant cross-sectional area means that the maximum and minimum values ​​of the cross-sectional area are within ±5% of the average value.

[0136] The lower limit of the longitudinal length (direction along the flow of carbon-containing gas) of the through-holes forming the 1-1A channel 41A, 1-1a channel 41a, 2-1B channel 42B, and 2-1b channel 42b is preferably 10 mm or more, more preferably 20 mm or more, and even more preferably 50 mm or more, from the viewpoint of sufficient aggregation of CNTs. The upper limit of the longitudinal length of the through-holes is preferably 1000 mm or less, more preferably 500 mm or less, and even more preferably 100 mm or less, from the viewpoint of suppressing the deposition of CNTs on the inner wall of the through-holes and increasing the amount of CNT aggregated strands recovered. The longitudinal length of the through-holes is preferably 10 mm or more and 1000 mm or less, more preferably 20 mm or more and 500 mm or less, and even more preferably 30 mm or more and 1000 mm or less.

[0137] The lower limit of the cross-sectional area of ​​the through-holes forming the first-to-second channels 41C and the second-to-second channels 42D is 0.01 mm, from the viewpoint of preventing clogging of the CNT bundled strands. 2 The above is preferable, 0.02 mm 2 The above is preferable, 0.1 mm 2 The above is preferable, 0.2 mm 2 The above is more preferable, 0.5 mm 2 The above is even more preferable. The upper limit of the cross-sectional area of ​​each through-hole is, from the viewpoint of the ease with which CNT bundled strands can be assembled, for example, 100 mm. 2 The following is preferable: 10 mm 2 The following is more preferable, 1 mm 2 The following is even more preferable.

[0138] The lower limit of the longitudinal length (direction along the flow of carbon-containing gas) of the through-holes forming the first-to-second channels 41C and the second-to-second channels 42D is preferably 5 mm or more, more preferably 10 mm or more, and even more preferably 20 mm or more, from the viewpoint of sufficiently assembling the CNT bundle wires. The upper limit of the longitudinal length of the through-holes is preferably 1000 mm or less, more preferably 100 mm or less, and even more preferably 50 mm or less, from the viewpoint of suppressing the deposition of CNT bundle wires on the inner wall of the through-holes and increasing the amount of CNT bundle wires recovered. The longitudinal length of the through-holes is preferably 5 mm or more and 1000 mm or less, more preferably 10 mm or more and 100 mm or less, and even more preferably 5 mm or more and 50 mm or less.

[0139] <Other configurations> The CNT bundle wire manufacturing apparatus of this embodiment may include a CNT bundle wire guide pipe 65 provided on the opposite side of the carbon-containing gas supply port 62 of the first-third structure 53. Preferably, the CNT bundle wire guide pipe is provided on the downstream extensions of the first-second flow path 41C and the second-second flow path 42D provided in the first-third structure. This ensures that the multiple CNT bundle wires exiting the first-third structure 53 are recovered in a separated state without becoming entangled. [Examples]

[0140] This embodiment will be described in more detail by reference to examples. However, this embodiment is not limited by these examples.

[0141] [Example 1] As apparatus 1, a carbon nanotube bundled wire manufacturing apparatus having a configuration similar to the carbon nanotube bundled wire manufacturing apparatus shown in Figure 2 is prepared. The specific configuration is as follows.

[0142] Apparatus 1 is a carbon nanotube synthesis furnace (quartz tube, hollow section diameter 50 mm (cross-sectional area approximately 2000 mm²) 2 ))The carbon nanotube synthesis furnace comprises a carbon-containing gas supply port located at one end (left side in Figure 2), and a first channel (maximum diameter 10 mm, length 500 mm) and a second channel (maximum diameter 10 mm, length 500 mm) located at the end opposite to the end with the carbon-containing gas supply port (right side in Figure 2). The first and second channels are arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace. The distance from the carbon-containing gas supply port end of the CNT synthesis furnace to the carbon-containing gas supply port end of the first and second channels is 2000 mm. A slurry sprayer containing a catalyst (ferrocene) dissolved in toluene is placed near the carbon-containing gas supply port inside the CNT synthesis furnace. A winding device for CNT bundles is placed downstream of the first and second channels.

[0143] Using apparatus 1, a carbon nanotube assembly line of sample 1 is fabricated. In apparatus 1, argon gas with a concentration of 100% by volume is supplied to the CNT synthesis furnace from the carbon-containing gas supply port at a flow rate of 1000 cc / min (flow velocity 3.4 cm / sec) for 50 minutes while the temperature inside the electric furnace is raised to 1200°C. Next, the argon gas is switched to hydrogen gas (1000 cc / min), and methane gas is supplied at a flow rate of 50 cc / min (flow velocity 0.17 cm / sec), and carbon disulfide (CS2) gas at a flow rate of 1 cc / min (flow velocity 0.003 cm / sec) for 120 minutes. The total flow velocity of the mixed gas (carbon-containing gas) containing hydrogen gas, methane gas, and carbon disulfide is 3.6 cm / sec.

[0144] The catalyst particles are released into the CNT synthesis furnace by supplying hydrogen gas, methane gas, and carbon disulfide gas as described above. Subsequently, CNTs grow in the CNT synthesis furnace, and these CNTs aggregate within the first and second channels, respectively, to form two CNT aggregation lines. These CNT aggregation lines are then wound up by a winding device, and the two CNT aggregation lines are recovered.

[0145] [Measurement of carbon nanotube cluster lines] (degree of orientation) The degree of orientation of the CNTs is measured for each of the two carbon nanotube bundle lines of sample 1. The method for calculating the degree of orientation is the same as the method described in Embodiment 1, so the explanation will not be repeated.

[0146] Two CNTs in Sample 1 collection line The degree of orientation of the CNTs in each of these is 0.8 and 0.9. This confirms that in the CNT bundle line obtained with apparatus 1, the CNTs are bundled in an orientation along their longitudinal direction.

[0147] (shape) The length and diameter of each of the two carbon nanotube bundles in sample 1 are measured. The method for measuring the length and diameter is the same as the method described in Embodiment 1, so the explanation will not be repeated.

[0148] Two CNTs in Sample 1 collection line The lengths of the two CNTs are 10m and 12m respectively. collection line The respective diameters are Φ0.1mm and Φ0.08mm.

[0149] [Example 2] As apparatus 2, a carbon nanotube bundled wire manufacturing apparatus having a configuration similar to the carbon nanotube bundled wire manufacturing apparatus shown in Figure 4 is prepared. The specific configuration is as follows.

[0150] Apparatus 2 is a carbon nanotube synthesis furnace (alumina tube, hollow section diameter 80 mm (cross-sectional area 6000 mm²) 2 (Cross-sectional shape: roughly circular) )) The carbon-containing gas supply port is located at one end of the carbon nanotube synthesis furnace (left side in Figure 4), and the 1-1 structure (1-1A channel, 1-1a channel, 2-1B channel and 2-1b channel, cross-sectional area 1 mm²) is located at the end opposite to the end of the carbon nanotube synthesis furnace where the carbon-containing gas supply port is located (right side in Figure 4). 2The structure comprises a total number of flow channels (total through-holes) of 20 per inch and a length of 50 mm, and a first-second structure (first-second flow channel: maximum diameter 30 mm, length 1000 mm) and a second-second structure (second-second flow channel: maximum diameter 30 mm, length 1000 mm) located downstream of the first-first structure. The distance from the carbon-containing gas supply port end of the CNT synthesis furnace to the carbon-containing gas supply port end of the first-first structure is 2500 mm. A catalyst (ferrocene) is placed near the carbon-containing gas supply port inside the CNT synthesis furnace. A winding device for CNT bundled wires is placed downstream of the first-second and second-second structures. It is preferable that each flow channel, such as the second-first and second-second structures, draws the CNT bundled wires coming out of the honeycomb from upstream to downstream to efficiently bundle them and promote the formation of bundled wires.

[0151] Using apparatus 2, carbon nanotube bundles of sample 2 are fabricated. In apparatus 2, argon gas with a concentration of 100% by volume is supplied to the CNT synthesis furnace from the carbon-containing gas supply port at a flow rate of 1000 cc / min (flow velocity 3.4 cm / sec) for 50 minutes while the temperature inside the electric furnace is raised to 1000°C. Next, the argon gas is switched to hydrogen gas (4000 cc / min), and ethylene gas is supplied at a flow rate of 200 cc / min (flow velocity 0.17 cm / sec), and carbon disulfide (CS2) gas at a flow rate of 4 cc / min (flow velocity 0.003 cm / sec) for 120 minutes. hydrogen gas, ethylene The overall flow velocity of the mixed gas (carbon-containing gas) including gas and carbon disulfide is 3.6 cm / sec.

[0152] The above hydrogen gas, ethylene The catalyst disintegrates upon the supply of gas and carbon disulfide gas, releasing catalyst particles into the CNT synthesis furnace. Subsequently, CNTs grow within the furnace, and these CNTs aggregate within the 1-1 structure to form CNT bundled wires. These CNT bundled wires then aggregate within the 1-2 structure and the 2-2 structure, respectively, to form two CNT bundled wires. The CNT bundled wires are then wound up using a winding device, and the two CNT bundled wires are recovered.

[0153] [Measurement of carbon nanotube cluster lines] (degree of orientation) For each of the two carbon nanotube bundles in sample 2, the degree of orientation of the CNTs and the degree of orientation of the CNT bundle strands are measured. The method for calculating the degree of orientation is the same as the method described in Embodiments 1 and 3, so the explanation will not be repeated.

[0154] The degree of orientation of CNTs in each of the two CNT cluster lines of sample 2 is 0. 82 and 0. The answer is 89. The degree of orientation of the CNT bundle strands in each of the two CNT bundle lines of sample 2 is 0. 86 and 0. The value is 92. This confirms that in the CNT bundle line obtained by apparatus 2, the CNTs and CNT bundle strands are oriented in their longitudinal direction.

[0155] (shape) The length and diameter of each of the two carbon nanotube bundles in sample 2 are measured. The method for measuring the length and diameter is the same as the method described in Embodiment 1, so the explanation will not be repeated.

[0156] Two CNTs in Sample 2 collection line The lengths of the two CNTs are 10m and 15m respectively. collection line The respective diameters are 0.8 mm and 1.2 mm.

[0157] [Example 3] As apparatus 3, a carbon nanotube bundled wire manufacturing apparatus having a configuration similar to the carbon nanotube bundled wire manufacturing apparatus shown in Figure 7 is prepared. The specific configuration is as follows.

[0158] Apparatus 3 comprises a carbon nanotube synthesis furnace (alumina tube, hollow section diameter Φ50 mm, length 1500 mm), a carbon-containing gas supply port located at one end of the carbon nanotube synthesis furnace (left side in Figure 7), and the first to third structures (1-1A channel, 1-1a channel, 1-1B channel, and 1-1b channel with a cross-sectional area of ​​2 mm²) located at the end opposite to the end of the carbon nanotube synthesis furnace where the carbon-containing gas supply port is located (right side in Figure 7). 2 , Cross-sectional area of ​​the 1st-2nd channel and the 2nd-2nd channel: 2 mm² 2 The structure comprises 100 through-holes on the upstream side connected to the 1st-2nd channel and the 2nd-2nd channel, each 50 mm long, with 100 holes on the upstream main surface and 2 holes on the downstream main surface, and two guide pipes (5 mm in diameter, 1000 mm in length) provided on the downstream side of the 1st-1st structure. The distance from the carbon-containing gas supply port end of the CNT synthesis furnace to the carbon-containing gas supply port end of the 1st-3rd structure is 2000 mm. A catalyst (ferrocene) is placed near the carbon-containing gas supply port inside the CNT synthesis furnace. A winding device for the CNT bundle is placed on the downstream side of the guide pipe.

[0159] Using apparatus 3, carbon nanotube bundles of sample 3 are fabricated. In apparatus 3, argon gas with a concentration of 100% by volume is supplied to the CNT synthesis furnace from the carbon-containing gas supply port at a flow rate of 1000 cc / min (flow velocity 3.4 cm / sec) for 50 minutes, while the temperature inside the electric furnace is raised to 1300°C. Next, the argon gas is switched to hydrogen gas (1000 cc / min), and methane gas is supplied at a flow rate of 50 cc / min (flow velocity 0.17 cm / sec), and carbon disulfide (CS2) gas at a flow rate of 1 cc / min (flow velocity 0.003 cm / sec) for 120 minutes. The total flow velocity of the mixed gas (carbon-containing gas) containing argon gas, methane gas, and carbon disulfide is 3.6 cm / sec.

[0160] The supply of hydrogen gas, methane gas, and carbon disulfide gas causes the catalyst to disintegrate, releasing catalyst particles into the CNT synthesis furnace. Subsequently, CNTs grow within the furnace, and these CNTs aggregate inside the 1st-3rd structures to form two CNT aggregation lines, which then enter the guide tube. The CNT aggregation lines are then wound up by a winding device, and the two CNT aggregation lines are recovered.

[0161] [Measurement of carbon nanotube cluster lines] (degree of orientation) For each of the two carbon nanotube bundles in sample 3, the degree of orientation of the CNTs and the degree of orientation of the CNT bundle strands are measured. The method for calculating the degree of orientation is the same as the method described in Embodiments 1 and 3, so the explanation will not be repeated.

[0162] The orientation degrees of the CNTs in each of the two CNT bundle lines of sample 3 are 0.86 and 0.93. The orientation degrees of the CNT bundle wires in each of the two CNT bundle lines of sample 3 are 0.87 and 0.91. This confirms that in the CNT bundle lines obtained with apparatus 3, the CNTs and CNT bundle wires are oriented and bundled in their longitudinal direction.

[0163] (shape) The length and diameter of each of the two carbon nanotube bundles in sample 3 are measured. The method for measuring the length and diameter is the same as the method described in Embodiment 1, so the explanation will not be repeated.

[0164] The lengths of the two CNT clusters in sample 3 are 100m and 150m, respectively. collection line The respective diameters are 0.2 mm and 0.3 mm.

[0165] [Comparative Example 1] As device 4, a device with the configuration shown in Figure 11 is prepared. Device 4 has basically the same configuration as device 1, except that it does not have a first flow path, a second flow path, and a winding device.

[0166] When CNT bundles are synthesized using apparatus 4 under the same conditions as in Example 1, the CNT bundles become entangled in an unoriented state within the CNT synthesis furnace, making it impossible to form CNT bundles in which the CNTs are oriented in the longitudinal direction.

[0167] [Comparative Example 2] Device 5 is prepared, which has basically the same configuration as device 2, except that it does not have the 1st-2 structure, the 2nd-2 structure, and the winding device.

[0168] When CNT bundles are synthesized using apparatus 5 under the same conditions as in Example 2, as shown in Figure 12, the multiple CNT bundles emitted from the 1-1 structure become entangled in an unoriented state, making it impossible to obtain a CNT bundle in which the CNT bundles are oriented in the longitudinal direction.

[0169] As described above, embodiments and examples of this disclosure have been explained, but it is also intended from the outset that the configurations of each of the above embodiments and examples may be combined as appropriate or modified in various ways. The embodiments and examples disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the embodiments and examples described above, and all modifications within the scope of the claims are intended to be included in the meaning of equivalents and within the scope. [Explanation of symbols]

[0170] 1 Carbon nanotube, 11 First carbon nanotube group, 11A First A carbon nanotube group, 11a First a carbon nanotube group, 12 Second carbon nanotube group, 12B Second B carbon nanotube group, 12b Second b carbon nanotube group, 21A First A carbon nanotube bundle wire, 21a First a carbon nanotube bundle wire, 22B Second B carbon nanotube bundle wire, 22b Second b carbon nanotube bundle wire, 27 Catalyst particle, 31 First carbon nanotube bundle wire, 32 Second carbon nanotube bundle wire, 40A First A structure, 40A-1 First A-1 part, 40A-2 First A-2 part, 40B First B structure, 40B-1 First B-1 part, 40B-2 First B-2 part, 41 First channel, 41A First-1A channel, 41a First-1a channel, 41C Channel 1-2, 42 Channel 2, 42B Channel 2-1B, 42b Channel 2-1b, 42D Channel 2-2, 51 Structure 1-1, 52A Structure 1-2, 52B Structure 2-2, 53 Structure 1-3, 60 Carbon nanotube synthesis furnace, 61 Heating device, 62 Carbon-containing gas supply port, 63 Liquid deposition device, 64 Winding device, 65 Guide tube, 100a, 100b, 100c Carbon nanotube bundled wire manufacturing apparatus

Claims

1. The first step involves supplying a carbon-containing gas to multiple suspended catalyst particles in a tubular carbon nanotube synthesis furnace, thereby growing carbon nanotubes from each of the multiple catalyst particles to obtain multiple carbon nanotubes. The system comprises a second step of assembling the plurality of carbon nanotubes to obtain a plurality of carbon nanotube bundle lines, The second step is, Step 2A involves aligning a first carbon nanotube group, composed of a portion of the plurality of carbon nanotubes, along the longitudinal direction of the carbon nanotubes within a first channel to obtain a first carbon nanotube assembly line. The process includes a second B step, in which a second carbon nanotube group, composed of a portion of the plurality of carbon nanotubes different from the plurality of carbon nanotubes constituting the first carbon nanotube group, is assembled in a second channel in an orientation along the longitudinal direction of the carbon nanotubes to obtain a second carbon nanotube assembly line, The first carbon nanotube group includes a first A carbon nanotube group composed of a portion of a plurality of carbon nanotubes constituting the first carbon nanotube group, and a first a carbon nanotube group composed of a portion of a plurality of carbon nanotubes constituting the first carbon nanotube group that is different from the plurality of carbon nanotubes constituting the first A carbon nanotube group. The first channel includes a first-1A channel and a first-1a channel arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace, and a first-2 channel provided downstream of the carbon-containing gas flow in the first-1A channel and the first-1a channel. The above step 2A is, Step 2A-1A involves assembling the group of carbon nanotubes described above in the channel 1-1A in an orientation along the longitudinal direction of the carbon nanotubes to obtain a bundled wire of carbon nanotubes described above. Step 2A-1a involves assembling the group of carbon nanotubes in the channel 1-1a in an orientation along the longitudinal direction of the carbon nanotubes to obtain a bundled wire of carbon nanotubes, The process includes a second A-2 step of assembling a plurality of carbon nanotube bundle wires, including the first A carbon nanotube bundle wire and the first a carbon nanotube bundle wire, in the first-2 channel, oriented along the longitudinal direction of the carbon nanotube bundle wires, to obtain the first carbon nanotube bundle wire. The second carbon nanotube group includes a second B carbon nanotube group composed of a portion of the plurality of carbon nanotubes constituting the second carbon nanotube group, and a second b carbon nanotube group composed of a portion of the plurality of carbon nanotubes constituting the second carbon nanotube group that are different from the plurality of carbon nanotubes constituting the second B carbon nanotube group. The second channel includes a second-1B channel and a second-1b channel provided in parallel along the longitudinal direction of the carbon nanotube synthesis furnace, and a second-2 channel provided downstream of the carbon-containing gas flow in the second-1B channel and the second-1b channel. The above-mentioned second B step is, The second B-1B step involves assembling the second B carbon nanotube group in the second B channel in an orientation along the longitudinal direction of the carbon nanotubes to obtain a second B carbon nanotube bundle wire, The second B-1b step involves assembling the second b carbon nanotube group in the second B-1b channel, oriented along the longitudinal direction of the carbon nanotubes, to obtain a second b carbon nanotube bundle wire, The process includes a second B-2 step of assembling a plurality of carbon nanotube bundle wires, including the second B carbon nanotube bundle wire and the second b carbon nanotube bundle wire, in the second B-2 channel, oriented along the longitudinal direction of the carbon nanotube bundle wires, to obtain the second carbon nanotube bundle wire, The 1-1A channel, the 1-1a channel, the 2-1B channel, and the 2-1b channel are provided in the same 1-1 structure. The first-second channel is provided in a first-second structure that is different from the first-first structure. The second-second channel is provided in a second-second structure that is different from the first-first structure. The first- and second structures consist of a tubular portion and a funnel-shaped portion connected to one end of the tubular portion. In the first and second structures, the smaller diameter end of the funnel-shaped portion is connected to the tubular portion. The larger diameter end of the funnel-shaped portion of the first-second structure is positioned facing the first-first structure. The second-second structure comprises a tubular portion and a funnel-shaped portion connected to one end of the tubular portion. In the 2-2 structure described above, the end with the smaller diameter of the funnel-shaped portion is connected to the tubular portion. A method for manufacturing a carbon nanotube bundle, wherein the larger diameter end of the funnel-shaped portion of the second-second structure is positioned facing the first-first structure.

2. A first step of obtaining a plurality of carbon nanotubes by supplying a carbon-containing gas to a plurality of suspended catalyst particles in a tubular carbon nanotube synthesis furnace, thereby growing carbon nanotubes from each of the plurality of catalyst particles, The system comprises a second step of assembling the plurality of carbon nanotubes to obtain a plurality of carbon nanotube bundle lines, The second step is, Step 2A involves aligning a first carbon nanotube group, composed of a portion of the plurality of carbon nanotubes, along the longitudinal direction of the carbon nanotubes within a first channel to obtain a first carbon nanotube assembly line. The process includes a second B step, in which a second carbon nanotube group, composed of a portion of the plurality of carbon nanotubes different from the plurality of carbon nanotubes constituting the first carbon nanotube group, is assembled in a second channel in an orientation along the longitudinal direction of the carbon nanotubes to obtain a second carbon nanotube assembly line, The first carbon nanotube group includes a first A carbon nanotube group composed of a portion of a plurality of carbon nanotubes constituting the first carbon nanotube group, and a first a carbon nanotube group composed of a portion of a plurality of carbon nanotubes constituting the first carbon nanotube group that is different from the plurality of carbon nanotubes constituting the first A carbon nanotube group. The first channel includes a first-1A channel and a first-1a channel arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace, and a first-2 channel provided downstream of the carbon-containing gas flow in the first-1A channel and the first-1a channel. The above-mentioned step 2A is, Step 2A-1A involves assembling the group of carbon nanotubes described above in the channel 1-1A in an orientation along the longitudinal direction of the carbon nanotubes to obtain a bundled wire of carbon nanotubes described above. Step 2A-1a involves assembling the group of carbon nanotubes in the channel 1-1a in an orientation along the longitudinal direction of the carbon nanotubes to obtain a bundled wire of carbon nanotubes, The process includes a second A-2 step of assembling a plurality of carbon nanotube bundle wires, including the first A carbon nanotube bundle wire and the first a carbon nanotube bundle wire, in the first-2 channel, oriented along the longitudinal direction of the carbon nanotube bundle wires, to obtain the first carbon nanotube bundle wire. The second carbon nanotube group includes a second B carbon nanotube group composed of a portion of the plurality of carbon nanotubes constituting the second carbon nanotube group, and a second b carbon nanotube group composed of a portion of the plurality of carbon nanotubes constituting the second carbon nanotube group that are different from the plurality of carbon nanotubes constituting the second B carbon nanotube group. The second channel includes a second-1B channel and a second-1b channel provided in parallel along the longitudinal direction of the carbon nanotube synthesis furnace, and a second-2 channel provided downstream of the carbon-containing gas flow in the second-1B channel and the second-1b channel. The above-mentioned second B step is, The second B-1B step involves assembling the second B carbon nanotube group in the second B channel in an orientation along the longitudinal direction of the carbon nanotubes to obtain a second B carbon nanotube bundle wire, The second B-1b step involves assembling the second b carbon nanotube group in the second B-1b channel, oriented along the longitudinal direction of the carbon nanotubes, to obtain a second b carbon nanotube bundle wire, The process includes a second B-2 step of assembling a plurality of carbon nanotube bundle wires, including the second B carbon nanotube bundle wire and the second b carbon nanotube bundle wire, in the second B-2 channel, oriented along the longitudinal direction of the carbon nanotube bundle wires, to obtain the second carbon nanotube bundle wire, The 1-1A channel, the 1-1a channel, the 1-2 channel, the 2-1B channel, the 2-1b channel, and the 2-2 channel are provided in the same 1-3 structure. The downstream ends of the carbon-containing gas flow in the 1-1A channel and the 1-1a channel are connected to the upstream end of the carbon-containing gas flow in the 1-2 channel. A method for manufacturing a carbon nanotube bundle, wherein the downstream ends of the carbon-containing gas flow in the 2-1B channel and the 2-1b channel are connected to the upstream end of the carbon-containing gas flow in the 2-2 channel.

3. A tubular carbon nanotube synthesis furnace, A carbon-containing gas supply port is provided on one end side of the carbon nanotube synthesis furnace, The carbon nanotube synthesis furnace comprises a first channel and a second channel provided on the end opposite to the end where the carbon-containing gas supply port is located, The first channel and the second channel are arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace. The cross-sectional areas of the first channel and the second channel are smaller than the cross-sectional area of ​​the carbon nanotube synthesis furnace. The first channel includes a first-1A channel and a first-1a channel provided in parallel on the carbon-containing gas supply port side of the carbon nanotube synthesis furnace, and a first-2 channel provided on the side of the first-1A channel and the first-1a channel opposite the carbon-containing gas supply port. The second channel includes a second-1B channel and a second-1b channel provided in parallel on the carbon-containing gas supply port side of the carbon nanotube synthesis furnace, and a second-2 channel provided on the side of the second-1B channel and the second-1b channel opposite to the carbon-containing gas supply port. The 1-1A channel, the 1-1a channel, the 2-1B channel, and the 2-1b channel are provided in the same 1-1 structure. The first-second channel is provided in a first-second structure that is different from the first-first structure. The second-second channel is provided in a second-second structure that is different from the first-first structure. The first- and second structures consist of a tubular portion and a funnel-shaped portion connected to the end of the tubular portion on the carbon-containing gas supply port side. In the first and second structures, the smaller diameter end of the funnel-shaped portion is connected to the tubular portion. The larger diameter end of the funnel-shaped portion of the first-second structure is positioned facing the first-first structure. The 2-2 structure comprises a tubular portion and a funnel-shaped portion connected to the end of the tubular portion on the carbon-containing gas supply port side. In the 2-2 structure described above, the end with the smaller diameter of the funnel-shaped portion is connected to the tubular portion. A carbon nanotube bundled wire manufacturing apparatus in which the larger diameter end of the funnel-shaped portion of the second-second structure is positioned facing the first-first structure.

4. A tubular carbon nanotube synthesis furnace, A carbon-containing gas supply port is provided on one end side of the carbon nanotube synthesis furnace, The carbon nanotube synthesis furnace comprises a first channel and a second channel provided on the end opposite to the end where the carbon-containing gas supply port is located, The first channel and the second channel are arranged in parallel along the longitudinal direction of the carbon nanotube synthesis furnace. The cross-sectional areas of the first channel and the second channel are smaller than the cross-sectional area of ​​the carbon nanotube synthesis furnace. The first channel includes a first-1A channel and a first-1a channel provided in parallel on the carbon-containing gas supply port side of the carbon nanotube synthesis furnace, and a first-2 channel provided on the side of the first-1A channel and the first-1a channel opposite the carbon-containing gas supply port. The second channel includes a second-1B channel and a second-1b channel provided in parallel on the carbon-containing gas supply port side of the carbon nanotube synthesis furnace, and a second-2 channel provided on the side of the second-1B channel and the second-1b channel opposite to the carbon-containing gas supply port. The 1-1A channel, the 1-1a channel, the 1-2 channel, the 2-1B channel, the 2-1b channel, and the 2-2 channel are provided in the same 1-3 structure. The ends of the 1-1A channel and the 1-1a channel opposite to the carbon-containing gas supply port are connected to the end of the 1-2 channel on the carbon-containing gas supply port side. A carbon nanotube bundle manufacturing apparatus, wherein the ends of the 2-1B channel and the 2-1b channel opposite to the carbon-containing gas supply port are connected to the end of the 2-2 channel on the carbon-containing gas supply port side.

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