JP2015003848A - Peeling device, carbon nanotube peeling method, and carbon nanotube manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently peel a carbon nanotube (CNT) from a substrate, and to prevent the damage of the substrate.SOLUTION: A plurality of blades provided in a peeling device 100 are arranged along a relative movement direction with respect to a substrate 30. The Rockwell hardness HR1 of a first blade 11 on the most downstream side in the relative movement direction and the Rockwell hardness HR2 of a second blade 12 on the most upstream side satisfy the relation of HR1>HR2.

Description

  The present invention relates to a peeling apparatus for peeling carbon nanotubes, a carbon nanotube peeling method, and a carbon nanotube manufacturing method.

  Patent Document 1 describes a scraper as an object for scraping carbon nanotubes (hereinafter also referred to as “CNT”) grown on a substrate from the substrate.

  Although the application is different from Patent Document 1, Patent Document 2 describes a blade cleaning device for cleaning a photosensitive drum used in an electronic copying machine or the like.

JP 2005-67916 A JP 59-24875 A

  In the scraper described in Patent Document 1, when the CNT on the base material cannot be peeled off at once, it is necessary to peel off the CNT remaining on the base material by repeating the scraping operation. At this time, the number of repetitions of the scraping operation by the scraper increases, so that the process time is increased, and the base material is easily damaged, and the CNT growth failure occurs when the base material is reused. obtain. Similar problems can occur when using the blade cleaning device of Patent Document 2.

  The present invention has been made in view of such a problem, and provides a peeling device capable of efficiently peeling CNT from a base material and preventing damage to the base material, and using the peeling device. An object of the present invention is to provide a method for peeling off CNTs and a method for producing CNTs.

  In order to solve the above-mentioned problems, a peeling apparatus according to the present invention is a peeling apparatus for peeling carbon nanotubes on a substrate, the end of which is the side on which the carbon nanotubes on the substrate are present. A plurality of blades that move relative to the substrate and peel off the carbon nanotubes in contact with the surface of the substrate, the plurality of blades being aligned along a relative movement direction with respect to the substrate, The Rockwell hardness HR1 of the most downstream blade in the relative movement direction and the Rockwell hardness HR2 of the most upstream blade satisfy the relationship HR1> HR2.

  In the peeling apparatus according to the present invention, it is more preferable that the HR1 and HR2 satisfy a relationship of 1 ≦ HR1-HR2 ≦ 70.

  In the peeling apparatus according to the present invention, it is more preferable that the plurality of blades are aligned so that the Rockwell hardness of the blades decreases in the order from the most downstream side to the most upstream side in the relative movement direction.

  The carbon nanotube peeling method according to the present invention is such that, among the plurality of blades of any of the peeling devices, the most downstream blade is brought into contact with a carbon nanotube on a substrate, and the plurality of blades and the substrate Is included, and includes a peeling step of peeling the carbon nanotube from the base material.

  The method for producing carbon nanotubes according to the present invention includes a peeling step of peeling carbon nanotubes on a substrate by any one of the peeling devices, and growing carbon nanotubes on the substrate from which carbon nanotubes have been peeled in the peeling step. And a growth process.

  According to the present invention, when the CNT grown on the base material is peeled, the base material is prevented from being damaged, and the CNT can be peeled efficiently from the base material.

It is a figure which shows typically the peeling apparatus which concerns on one Embodiment of this invention.

[Peeling device]
A peeling apparatus according to an embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a diagram schematically showing a peeling apparatus according to an embodiment of the present invention. As shown in FIG. 1, the peeling device 100 is a device for peeling carbon nanotubes (CNT) on a base material 30 and includes a plurality of blades. The peeling apparatus 100 includes a peeling unit 10 that holds the first blade 11 and the second blade 12.

  CNTs are present on the substrate 30. The CNTs on the substrate 30 are preferably aligned CNT aggregates grown on the substrate 30, and more preferably aligned CNTs grown so as to be vertically aligned on the substrate 30. . That is, the peeling apparatus 100 is particularly suitable for peeling the aligned CNT aggregate from the base material 30.

(CNT aligned aggregate)
The aligned CNT aggregate is a structure in which a large number of CNTs grown from the substrate 30 are aligned in a specific direction. The preferable specific surface area of the aligned CNT aggregate is 600 m ² / g or more, more preferably 800 m ² / g or more when the CNT is mainly unopened. A higher specific surface area is preferable because impurities such as metals or carbon impurities can be kept lower than several tens of percent (about 40%) of the weight.

The weight density is preferably 0.002 g / cm ³ or more and 0.2 g / cm ³ or less. If the weight density is 0.2 g / cm ³ or less, the connection between the CNTs constituting the aligned CNT aggregate is weakened, so it is easy to uniformly disperse the aligned CNT aggregate in a solvent or the like. become. That is, when the weight density is 0.2 g / cm ³ or less, it is easy to obtain a homogeneous dispersion. Further, when the weight density is 0.002 g / cm ³ or more, the integrity of the aligned CNT aggregate can be improved and the variation can be suppressed, so that handling becomes easy.

The aligned CNT aggregate oriented in a specific direction preferably has a high degree of orientation. High degree of orientation means
1. When X-ray diffraction intensity is measured by incident X-rays from a first direction parallel to the longitudinal direction of the CNT and a second direction orthogonal to the first direction (θ-2θ method), There exists a θ angle and a reflection direction in which the reflection intensity is greater than the reflection intensity from the first direction, and a θ angle and a reflection direction in which the reflection intensity from the first direction is greater than the reflection intensity from the second direction. Exist.

    2. A diffraction peak pattern showing the presence of anisotropy appears when X-ray diffraction intensity is measured (Laue method) using a two-dimensional diffraction pattern image obtained by X-ray incidence from a direction perpendicular to the longitudinal direction of CNT. To do.

    3. The Herman orientation coefficient is greater than 0 and less than 1 using the X-ray diffraction intensity obtained by the θ-2θ method or the Laue method. More preferably, it is 0.25 or more and 1 or less.

  1 above. To 3. It can be evaluated by at least one of the following methods. In the X-ray diffraction method described above, the diffraction intensity of the (CP) diffraction peak and the (002) peak due to packing between single-walled CNTs and the carbon six-membered ring structure constituting the single-walled CNTs (100 ), (110) Another feature is that the degree of diffraction peak intensity in the incident direction of the parallel and perpendicular to the peak is different.

  In order for the aligned CNT aggregate to exhibit orientation and a high specific surface area, the height (length) of the aligned CNT aggregate is preferably in the range of 10 μm to 10 cm. When the height is 10 μm or more, the orientation is improved. Further, when the height is 10 cm or less, the production can be performed in a short time, so that adhesion of carbon-based impurities can be suppressed and the specific surface area can be improved.

The G / D ratio of CNT is preferably 3 or more, more preferably 4 or more. The G / D ratio is an index generally used for evaluating the quality of CNTs. The Raman spectra of CNT measured by Raman spectroscopy system, the vibration mode is observed, called G band (1600 cm ^-1 vicinity) and D-band (1350 cm around ^-1). The G band is a vibration mode derived from a hexagonal lattice structure of graphite, which is a cylindrical surface of CNT, and the D band is a vibration mode derived from an amorphous part. Therefore, a higher peak intensity ratio (G / D ratio) between the G band and the D band can be evaluated as CNT having higher crystallinity.

(First blade 11 and second blade 12)
The first blade 11 and the second blade 12 move from the base material 30 by moving relative to the base material 30 with their end portions in contact with the surface on the side where the CNTs on the base material 30 exist. It is a thing for scraping off CNT. The first blade 11 and the second blade 12 are aligned along the direction of relative movement with respect to the substrate 30 (the direction of arrow B in the figure). Here, the relative movement means that one or both of the first blade 11 and the second blade 12 and the base material 30 move, so that the relative positional relationship between them changes continuously.

  The first blade 11 is located downstream of the second blade 12 in the relative movement direction described above. That is, the first blade 11 is located on the most downstream side in the relative movement direction, and the second blade 12 is located on the most upstream side in the relative movement direction. The Rockwell hardness HR1 of the first blade 11 and the Rockwell hardness HR2 of the second blade 12 satisfy the relationship of HR1> HR2. That is, the first blade 11 that first contacts the substrate 30 is harder than the second blade 12 that subsequently contacts the substrate 30.

  When the CNT on the base material is scraped off by one blade or the like and peeled off at once, it is necessary to peel off the CNT remaining on the base material by repeating the scraping operation. At this time, the number of repetitions of the scraping operation by the blade increases, so that the process time increases, and the substrate is easily damaged, and CNT growth failure occurs when the substrate is reused. obtain.

  Since the peeling apparatus 100 includes the first blade 11 and the second blade 12, even if there is CNT remaining on the base material 30 that cannot be completely peeled off by the first blade 11, it can be peeled off by the second blade 12. it can. Thereby, it is possible to peel more CNTs than a conventional peeling apparatus having only one blade by only relatively moving the peeling part 10 and the base material 30 once. That is, the peeling apparatus 100 can peel CNT more efficiently.

  The blade used for peeling the CNTs on the base material is preferably hard to some extent, but the harder the blade, the more easily the base material is damaged. In the peeling apparatus 100, the first blade 11 that first contacts the substrate 30 is harder than the second blade 12, and then the second blade 12 that contacts the substrate 30 is softer than the first blade 11. Therefore, it is possible to prevent the substrate 30 from being damaged as compared with the case where only a hard blade is used repeatedly. Further, since the CNT remaining on the base material 30 without being peeled off by the first blade 11 is in a state of being easily peeled off by the first blade 11, even if the second blade 12 is soft, the CNT remains on the base material 30. The remaining CNT can be peeled off.

  Thus, since the 1st braid | blade 11 located in the most downstream side is harder than the 2nd braid | blade 12 located in the most upstream side, the peeling apparatus 100 peels CNT from a base material efficiently. In addition, the substrate 30 can be prevented from being damaged.

  In the peeling apparatus 100, it is preferable that the Rockwell hardness HR1 of the first blade 11 and the Rockwell hardness HR2 of the second blade 12 satisfy the relationship of 1 ≦ HR1-HR2 ≦ 70. Thereby, the peeling apparatus 100 can more efficiently prevent the CNTs from being peeled off and more preferably prevent the base material 30 from being damaged. HR1-HR2 is more preferably 5 or more and 40 or less, and further preferably 10 or more and 20 or less.

  HR1 is preferably 70 or more and 130 or less, more preferably 90 or more and 125 or less, and further preferably 100 or more and 120 or less. With this configuration, the first blade 11 has a hardness that is more suitable for peeling of CNTs from the substrate 30. Furthermore, HR2 is preferably 50 or more and 120 or less, more preferably 70 or more and 115 or less, and further preferably 80 or more and 110 or less. With this configuration, the second blade 12 is hard to damage the base material 30 and has a hardness suitable for peeling off the CNT remaining on the base material 30.

  Note that HR1 and HR2 can be set as appropriate in consideration of the ease of peeling of the CNT, the ease of scratching the substrate, and the like. That is, as long as HR1> HR2 is satisfied, when the CNT is easily peeled off, blades having low HR1 and HR2 may be used as the first blade 11 and the second blade 12, respectively, and the substrate is not easily damaged. In this case, blades having high HR1 and HR2 may be used as the first blade 11 and the second blade 12, respectively.

  The material forming the first blade 11 and the second blade 12 is not particularly limited as long as it satisfies the relationship of HR1> HR2, and for example, metal or resin can be used. The material forming the first blade 11 and the second blade 12 is preferably a resin from the viewpoint of preventing damage to the substrate, and specific examples thereof include nylon, polyvinyl chloride, polypropylene (PP), polyethylene terephthalate (PET). ), Polyethylene (PE), ABS resin and the like.

  Here, the Rockwell hardness representing the hardness of the first blade 11 and the second blade 12 can be measured according to JIS B 7726 or JIS Z 2245.

  In the present embodiment, the configuration in which the peeling apparatus 100 includes two blades of the first blade 11 and the second blade 12 is described as an example, but the number is particularly limited as long as it includes a plurality of blades. Not.

  The plurality of blades included in the peeling apparatus 100 may be such that the most downstream blade is harder than the most upstream blade, but is arranged so that the Rockwell hardness of the blades decreases in order from the most downstream to the most upstream blade. More preferably. That is, for example, a third blade (Rockwell hardness HR3) and a fourth blade (Rockwell hardness HR4) are provided between the first blade 11 and the second blade 12, and the first blade 11, the third blade, When the four blades and the second blade 12 are aligned in this order, it is more preferable that these Rockwell hardnesses satisfy the relationship of HR1> HR3> HR4> HR2. Thereby, while being able to peel CNT from the base material 30 more efficiently, damage to the base material 30 can be prevented more reliably.

  As shown in FIG. 1, the first blade 11 and the second blade 12 are provided together in one peeling portion 10 so that the two blades move together as the peeling portion 10 moves. The blades may be configured, or may be provided in different peeling portions, and the two blades may be configured to move independently of each other. Here, in the plurality of blades provided in the peeling apparatus 100, it is preferable that the interval between the blades is narrow because the CNTs can be efficiently peeled. A preferable interval between the blades is 1 mm or more and 50 mm or less, more preferably 3 mm or more and 30 mm or less, and further preferably 5 mm or more and 20 mm or less.

  When the CNTs on the base material 30 are peeled using the peeling device 100, the angle formed by the first blade 11 and the second blade 12 with respect to the surface of the mounting table 20 is not limited. It is preferably at most 0 °, more preferably at least 30 ° and at most 60 °.

  The first blade 11 and the second blade 12 may be processed so that the tips thereof are parallel to the surface of the substrate 30 when contacting the surface of the substrate 30. In order to obtain such a structure, the tips of the first blade 11 and the second blade 12 are once sharply formed and then the tips are appropriately cut. At this time, the width of the tip in contact with the substrate 30 may be preferably 1 mm or more and 3 mm or less.

(Peeling part 10)
The peeling unit 10 holds the first blade 11 and the second blade 12 and moves in the direction of arrow A in FIG. 1, so that the CNTs on the substrate 30 are moved between the ends of the first blade 11 and the second blade 12. It can be brought into contact with the existing surface. Further, the peeling unit 10 may include a moving mechanism for moving the first blade 11 and the second blade 12 so that the first blade 11 and the second blade 12 move in the direction of arrow B in FIG. Good. As such a moving mechanism, a known moving mechanism such as a belt conveyor can be used.

(Mounting table 20)
The mounting table 20 is a table for mounting the base material 30 on which the CNTs are grown. FIG. 1 shows a state where the base material 30 is placed on the mounting table 20. The mounting table 20 may include a mechanism for moving the base material 30 so that the first blade 11 and the second blade 12 move relative to the base material 30 in the direction of arrow B in FIG. As such a moving mechanism, a known moving mechanism such as a belt conveyor can be used.

(Substrate 30)
The base material 30 is a base material for growing CNTs. For example, a base material 30 is provided with a catalyst layer that catalyzes the growth of CNTs on a flat substrate. As a material used for the substrate, it is preferable that the shape can be maintained even at a high temperature of 400 ° C. or higher. Specifically, metals such as iron, nickel, chromium, molybdenum, tungsten, titanium, aluminum, manganese, cobalt, copper, silver, gold, platinum, niobium, tantalum, lead, zinc, gallium, indium, germanium, and antimony And alloys and oxides containing these metals; nonmetals such as silicon, quartz, glass, mica, graphite, and diamond; and ceramics. Metals are preferable because they are low in cost compared to silicon and ceramics, and in particular, Fe-Cr (iron-chromium) alloys, Fe-Ni (iron-nickel) alloys, Fe-Cr-Ni (iron-chromium-nickel). ) Alloys are preferred.

  When a flat substrate is used, the thickness of the substrate is not particularly limited, and for example, a thin film having a thickness of about several μm to about several cm can be used. Preferably, it is 0.05 mm or more and 3 mm or less. If the thickness of the substrate is 3 mm or less, the substrate can be sufficiently heated in the CVD process, so that the CNT growth failure can be suppressed and the cost of the substrate can be reduced. If the thickness of the substrate is 0.05 mm or more, the deformation of the substrate due to carburization is suppressed, and the substrate itself is less likely to bend, which is advantageous for transport and reuse of the substrate. In addition, the carburization referred to in this specification means that the carbon component penetrates into the substrate.

  Although there is no restriction | limiting in particular in the shape and magnitude | size of a flat substrate, As a shape, a rectangular or square thing can be used.

(Carburization prevention layer)
A carburizing prevention layer may be formed on at least one of the front surface and the back surface of the substrate. It is desirable that carburization prevention layers are formed on both the front and back surfaces. This carburizing prevention layer is a protective layer for preventing the substrate from being carburized and deformed in the CNT growth process.

  The carburizing prevention layer is preferably made of a metal or a ceramic material, and particularly preferably a ceramic material having a high carburizing prevention effect. Examples of the metal include copper and aluminum. Examples of the ceramic material include aluminum oxide, silicon oxide, zirconium oxide, magnesium oxide, titanium oxide, silica alumina, chromium oxide, boron oxide, calcium oxide, zinc oxide and other oxides, aluminum nitride, and silicon nitride. Nitride can be exemplified, and aluminum oxide and silicon oxide are preferable because they have a high carburization prevention effect.

(catalyst)
When a carburization prevention layer is provided on the substrate or on the substrate, a catalyst is supported on the carburization prevention layer to form a catalyst layer. The catalyst only needs to be able to produce CNT. For example, iron, nickel, cobalt, molybdenum, and chlorides and alloys thereof, and these may be aluminum, alumina, titania, titanium nitride, and silicon oxide. It may be compounded or layered. For example, an iron-molybdenum thin film, an alumina-iron thin film, an alumina-cobalt thin film, an alumina-iron-molybdenum thin film, an aluminum-iron thin film, an aluminum-iron-molybdenum thin film, and the like can be exemplified. The amount of the catalyst may be within a range in which CNT can be produced, for example. When iron is used, the thickness of the catalyst layer is preferably 0.1 nm or more and 100 nm or less, and more preferably 0.5 nm or more and 5 nm or less. Preferably, it is 0.8 nm or more and 2 nm or less.

  In the present embodiment, a case where CNT has already grown on the base material 30 will be described. After the CNTs are peeled off by the peeling device 100, the base material 30 may be reused for the growth of CNTs.

  Next, the operation of the peeling apparatus 100 will be described.

  After the base material 30 is placed on the mounting table 20, the peeling part 10 is moved in the direction of arrow A, and the end portions of the first blade 11 and the second blade 12 are placed on the side where the CNTs on the base material 30 are present. Touch the surface. At this time, although the force which presses the 1st blade 11 and the 2nd blade 12 to the base material 30 is not limited, For example, it is preferable that they are 8N or more and 700N or less, and it is more preferable that they are 15N or more and 100N or less.

  If the force for pressing the blade against the substrate is weak, there is a gap between the surface of the substrate and the end of the blade, and the CNT may remain on the substrate without being peeled off. On the other hand, if the force for pressing the blade against the substrate is too strong, the substrate may be damaged or the end of the blade may be easily worn. By appropriately adjusting the force for pressing the blade against the base material, it is possible to prevent the CNT from remaining on the base material and to peel the CNT without damaging the base material.

  The first blade 11 and the second blade 12 are moved by moving at least one of the peeling unit 10 and the mounting table 20 in a state where the end portions of the first blade 11 and the second blade 12 are in contact with the surface of the substrate 30. Is moved relative to the substrate 30 in the direction of arrow B in FIG. At this time, the speed at which the first blade 11 and the second blade 12 move relative to the base material 30 is preferably, for example, 50 mm / s or more and 500 mm / s or less.

  Here, the peeling unit 10 and the mounting table 20 may be configured such that one is fixed and the other is moved, or both may be configured to move. For example, fixing the peeling unit 10 and moving the mounting table 20 on which the CNT-grown base material 30 is placed is advantageous when the peeling device 100 is incorporated into an apparatus that continuously manufactures CNTs. . That is, the CNT can be continuously peeled if the substrate is transported by a belt conveyor or the like, passed through a furnace for growing CNT, and then passed under the blade.

  By operating the peeling device 100 in this manner, the CNTs on the base material 30 are first scraped off by the first blade 11 on the downstream side in the relative movement direction, and the CNTs that remain on the base material 30 without being scraped off also. The second blade 12 on the upstream side in the relative movement direction is scraped off. The substrate from which the CNTs have been peeled can be reused for the growth of CNTs after a new catalyst layer is formed as necessary.

[Peeling method]
The stripping method according to the present invention is a stripping method for stripping CNTs, and of the plurality of blades of the stripping apparatus according to the present invention, the blade on the most downstream side is brought into contact with the CNTs on the substrate, It includes a peeling step in which the CNT is peeled from the base material by moving the base material relative to the base material.

  That is, since one embodiment of the peeling method according to the present invention is realized by the peeling device 100 described above, the description of one embodiment of the peeling method according to the present invention is the description of the peeling device 100 described above. Follow.

〔Production method〕
The manufacturing method according to the present invention is a manufacturing method for manufacturing CNTs, and includes a peeling step of peeling CNTs on a substrate by a peeling device according to the present invention, and a substrate from which CNTs have been peeled in the peeling step. And a growth step of growing CNTs.

(Peeling process)
Since one embodiment of the peeling process of the manufacturing method according to the present invention is realized by the above-described peeling device 100, the description of one embodiment of the peeling process of the manufacturing method according to the present invention is the above-described peeling device. According to the description of 100.

(Initialization process)
The manufacturing method according to an embodiment of the present invention may include an initialization process after the peeling process and before the growth process. In the initialization step, carbon impurities remaining on the substrate from which the CNTs have been peeled are removed.

  When the catalyst layer contains a carbon component when the substrate is reused, the growth of CNTs may become unstable, or the quality of the produced CNTs may deteriorate. This carbon component is considered to be derived from carbon impurities adhering to the substrate or the catalyst layer. Therefore, by removing the carbon impurities adhering to the base material or the catalyst layer, it is possible to stabilize the growth of the CNT when the base material is reused and to repeatedly produce high-quality CNT.

  Examples of the method for removing carbon impurities attached to the base material or the catalyst layer include a method of evaporating by heating at a high temperature, a method of acid cleaning, and the like.

The fact that the carbon component is removed from the substrate or the catalyst layer and does not contain the carbon component can be evaluated, for example, by measuring the Raman spectrum of the substrate surface. The carbon component can be detected in the vibration mode of graphite near 1593 cm ⁻¹ or the vibration mode of an amorphous carbon compound having low crystallinity near 1350 cm ⁻¹ . Therefore, it is preferable that these peaks are not observed in the substrate after the initialization step.

  The catalyst layer may remain on the substrate after the initialization step, or may be removed along with the removal of the carbon component. Even if the catalyst layer is removed in the initialization step, if the catalyst layer is formed in the catalyst layer formation step described later, the subsequent CNT generation will not be adversely affected. On the other hand, if the removal of carbon impurities is insufficient in the initialization step, even if a catalyst layer is formed thereon, the production and quality of CNT may be reduced in the subsequent CNT generation.

(Cleaning process)
The manufacturing method according to an embodiment of the present invention may further include a cleaning step after the initialization step and before the growth step. In the cleaning process, the substrate after the initialization process is cleaned. In the cleaning process, for example, the surface of the substrate is cleaned by a method of wiping the substrate surface with a cloth, a method of washing the substrate surface with water, or the like. The carbon component may remain on the surface of the substrate after the initialization step without being completely evaporated, but the remaining carbon component can be removed by cleaning the substrate after the initialization step. Since the adhesive force between the carbon component remaining on the substrate surface and the substrate or the catalyst fine particles is reduced by the initialization process, the carbon component can be easily removed by wiping, washing with water, or the like.

  In addition, the catalyst layer may remain on the base material after the cleaning step, or may be removed along with the cleaning of the base material surface. Even if the catalyst layer is removed in the cleaning process, it is only necessary to form the catalyst layer in the catalyst layer forming process to be described later.

(Catalyst layer formation process)
The manufacturing method according to an embodiment of the present invention may further include a catalyst layer forming step after the cleaning step and before the growth step. In the catalyst layer forming step, the catalyst layer is provided on the substrate after the initialization step or after the cleaning step is further performed after the initialization step. Thereby, even if it is a base material which used for manufacture of CNT once and peeled CNT, it can be used for manufacture of CNT again more suitably.

  When the CNT growth process is performed for the second time using the substrate with the catalyst layer on the outermost surface as it is after the initialization process, the growth of the CNT becomes unstable or the quality of the generated CNT deteriorates. There is a case. Possible causes are that the density and diameter of the catalyst fine particles in the catalyst layer are not maintained in the same optimum state as the first CNT growth process, or the catalyst fine particles in the catalyst layer have been removed in the initialization process. And so on.

  By performing the catalyst layer forming step, a new catalyst layer is formed on the outermost surface of the substrate by newly laminating the catalyst layer so as to cover the substrate or the catalyst layer after the initialization step. Thereby, when implementing the next CVD, the catalyst layer on a base material can be made into an optimal state.

  Either the wet process or the dry process may be applied to the formation of the catalyst layer on the substrate, that is, the catalyst forming step referred to in the present invention. For example, a sputtering vapor deposition method or a liquid coating / firing method in which metal fine particles are dispersed in an appropriate solvent can be applied. In addition, the catalyst layer can be formed into an arbitrary shape by combining patterning using well-known photolithography, nanoimprinting, or the like.

  By adjusting the patterning of the catalyst deposited on the substrate, the shape of the aligned single-walled CNT aggregate can be controlled arbitrarily, such as thin film, cylindrical, prismatic, and other complicated shapes. it can. In particular, the aligned single-walled CNT aggregate is extremely small in thickness (height) compared to its length and width, but the length and width can be controlled arbitrarily by patterning the catalyst. The thickness dimension can be arbitrarily controlled by the growth time of each single-walled CNT constituting the single-walled aligned CNT aggregate.

(Formation process)
The manufacturing method according to an embodiment of the present invention may further include a formation step after the catalyst layer forming step and before the growth step. The formation process is a process of heating the catalyst and / or the reducing gas while setting the environment surrounding the catalyst layer on the substrate as the reducing gas environment. By this step, at least one of the effects of reduction of the catalyst, promotion of atomization that is suitable for the growth of CNT of the catalyst, and improvement of the activity of the catalyst appears.

  The temperature of the catalyst and / or reducing gas in the formation step is preferably 400 ° C. or higher and 1100 ° C. or lower. The time for the formation step is preferably 3 minutes or more and 30 minutes or less, and more preferably 3 minutes or more and 8 minutes or less. If the time of the formation step is within this range, the coarsening of the catalyst fine particles can be prevented, and the generation of multi-walled carbon nanotubes in the growth step can be suppressed.

  For example, when iron is used as a catalyst, an iron hydroxide thin film or an iron oxide thin film is formed, and at the same time or after that, reduction and fine particle formation occur to form iron fine particles. When the material of the carburizing prevention layer is alumina and the catalyst metal is iron, the iron catalyst layer is reduced to fine particles, and many nanometer-sized iron fine particles are formed on the alumina layer. As a result, the catalyst is prepared as a catalyst suitable for production of CNTs.

(Growth process)
In the growth step, the surrounding environment of the substrate from which the CNTs were peeled in the peeling step is set as a source gas environment, and at least one of the catalyst and the source gas on the substrate is heated to grow the CNTs on the substrate. . That is, in the growth process, CNTs are grown on the substrate by a chemical vapor deposition (CVD) method.

  In the growth step, for example, the source gas is injected onto the substrate from a plurality of source gas injection ports arranged at positions facing the substrate. By configuring the injection port in this way, the source gas can be uniformly dispersed on the substrate, and the source gas can be consumed efficiently. As a result, the uniformity of the aligned CNT aggregates grown on the substrate can be improved, and the consumption of the raw material gas can be reduced.

  In the growth process, at least one of the catalyst and the source gas is heated. From the viewpoint of growing CNTs with a uniform density, it is preferable to heat at least the raw material gas. The heating temperature is more preferably 400 ° C to 1100 ° C.

  In the growth step, it is preferable to inject the raw material gas while the base material and the injection port move relatively. Here, the relative movement means that one or both of the base material and the injection port move, and the relative positional relationship between the two continuously changes. Specifically, there is a method in which the substrate is placed on a belt conveyor and continuously conveyed under the injection port from which the raw material gas is injected.

  The growth process can be performed using a synthesis furnace (reaction chamber) that receives a substrate carrying a catalyst and a heating means, for example, a thermal CVD furnace, a thermal heating furnace, an electric furnace, a drying furnace, a thermostat. , Atmosphere furnace, gas replacement furnace, muffle furnace, oven, vacuum heating furnace, plasma reactor, microplasma reactor, RF plasma reactor, electromagnetic heating reactor, microwave irradiation reactor, infrared irradiation heating furnace, ultraviolet heating reaction Any known production apparatus such as a furnace, an MBE reaction furnace, an MOCVD reaction furnace, or a laser heating apparatus can be used.

  The CNTs grown on the substrate were peeled and collected using the peeling devices each having the first blade and the second blade shown in Table 1.

  The peeling apparatus of Example 1 includes a nylon blade as the first blade and a PP blade as the second blade. The hardness (HR1) of the first blade is 120, the hardness (HR2) of the second blade is 105, and HR1-HR2 is 15.

  The peeling apparatus of Example 2 includes a polyvinyl chloride blade as the first blade and a PET blade as the second blade. HR1 is 118, HR2 is 100, and HR1-HR2 is 18.

  The peeling apparatus of Example 3 includes a polyvinyl chloride blade as the first blade and a PP blade as the second blade. HR1 is 118, HR2 is 105, and HR1-HR2 is 13.

  The peeling apparatus of Example 4 includes a nylon blade as the first blade and a PET blade as the second blade. HR1 is 120, HR2 is 100, and HR-HR2 is 20.

  The peeling device of Comparative Example 1 includes a nylon blade as the first blade and a nylon blade as the second blade. HR1 is 120, HR2 is 120, and HR1-HR2 is 0.

  The peeling device of Comparative Example 2 includes a PP blade as the first blade and a nylon blade as the second blade. HR1 is 105, HR2 is 120, and HR1-HR2 is -15.

(substrate)
As the substrate, a flat plate of Fe—Cr alloy SUS430 (manufactured by JFE Steel Corporation, Cr 18%) having a width of 100 mm × a length of 100 mm and a thickness of 0.3 mm was used. When the surface roughness at a plurality of locations was measured using a laser microscope, the arithmetic average roughness Ra≈0.063 μm.

(Catalyst formation)
A catalyst was formed on the substrate by the following method. A silicon dioxide film (carburization prevention layer) having a thickness of 100 nm was formed on both the front and back surfaces of the substrate using a sputtering apparatus. Next, an aluminum oxide film (catalyst support layer) having a thickness of 10 nm and an iron film (catalyst) having a thickness of 1.0 nm were formed only on the surface of the substrate using a sputtering apparatus to obtain a base material.

(CNT growth conditions)
The obtained base material was placed in a reactor of a CVD apparatus maintained at a furnace temperature: 750 ° C. and a furnace pressure: 1.02 × 10 ⁵ Pa. In this furnace, He: 100 sccm and H ₂ : 900 sccm of mixed gas was introduced for 6 minutes. As a result, the catalyst made of iron oxide was reduced to promote the formation of fine particles in a state suitable for the growth of single-walled CNTs, and a large number of nanometer-sized iron fine particles were formed on the catalyst support layer (formation step).

Next, in a reactor maintained at a furnace temperature: 750 ° C. and a furnace pressure: 1.02 × 10 ⁵ Pa, He: 850 sccm, C ₂ H ₄ : 100 sccm and H ₂ O-containing He (relative (Humidity 23%): A mixed gas of 50 sccm was supplied for 600 seconds. Thereby, single-walled CNT grew from each iron catalyst fine particle (growth process).

  After the growth step, He: 1000 sccm was supplied into the reaction furnace, and the remaining raw material gas and catalyst activator were removed (flash step). Thereby, an aggregate of single-walled CNTs aligned on the substrate was obtained.

(CNT peeling and recovery)
The first blade and the second blade were attached at an angle of 45 ° with respect to the surface of the mounting table. The distance between the first blade and the second blade was 2 mm. The blade pressing pressure of the first blade and the second blade against the substrate was 20 N, the moving speed of the first blade and the second blade was 50 mm / sec, and CNT was peeled and collected.

(Substrate cleaning)
After the separation and recovery of the CNT, the CNT remaining on the substrate was removed and the substrate was washed. The substrate was washed using a sponge impregnated with water and ethanol. After washing the substrate, moisture remaining on the substrate was dried by air drying.

(Reuse of base material)
After the catalyst was formed on the cleaned substrate by the same method as described above, CNTs were grown by the same method as described above. The grown CNTs were peeled and collected in the same manner as described above.

  Table 2 shows the amount of growth and exfoliation of CNT before and after the reuse of the substrate.

  As shown in Table 2, when the CNTs were peeled off and collected using the peeling devices of Examples 1 to 4, there was no significant change in the amount of CNT grown and peeled back and forth before and after the reuse of the base material. The CNTs were successfully grown, stripped and recovered both before and after reuse. That is, in the stripping apparatuses of Examples 1 to 4, even when the reuse of the substrate is repeated, the decrease in the amount of CNT growth is small and the stripping recovery rate can be maintained high.

  On the other hand, in the peeling apparatus of Comparative Example 1, since both of the hard blades are used, the peeling recovery rate is high, but it is presumed that the substrate is easily scratched and the CNT growth amount at the time of reuse is reduced. Is done.

  Moreover, in the peeling apparatus of Comparative Example 2, since the first blade was soft, the CNT could not be peeled much with the first blade, and the CNT peeling recovery rate was lower than that of the peeling apparatuses of Examples 1 to 4. That is, in the peeling apparatus of Comparative Example 2, since the first blade is soft, there are many CNTs that cannot be peeled off by the first blade, and the remaining CNTs are not easily peeled off. For this reason, it is presumed that the second blade cannot be sufficiently peeled even if it is hard. However, since the degree of damage to the base material is less than that of the peeling device of Comparative Example 1, the amount of CNT grown at the time of recycling was difficult to decrease.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be used in a carbon nanotube manufacturing technique.

DESCRIPTION OF SYMBOLS 10 Peeling part 11 1st blade 12 2nd blade 20 Mounting stand 30 Base material 100 Peeling apparatus

Claims (5)

A peeling device for peeling carbon nanotubes on a substrate,
A plurality of blades that move relative to the substrate and peel off the carbon nanotubes in a state where the end portion is in contact with the surface on the side where the carbon nanotubes exist on the substrate,
The plurality of blades are aligned along a direction of relative movement with respect to the substrate;
The peeling apparatus according to claim 1, wherein the Rockwell hardness HR1 of the most downstream blade and the Rockwell hardness HR2 of the most upstream blade in the relative movement direction satisfy a relationship of HR1> HR2.   The peeling apparatus according to claim 1, wherein the HR1 and HR2 satisfy a relationship of 1 ≦ HR1-HR2 ≦ 70.   3. The peeling device according to claim 1, wherein the plurality of blades are aligned so that the Rockwell hardness of the blades decreases in order from the most downstream side to the most upstream side in the relative movement direction. .   The blades on the most downstream side of the plurality of blades of the peeling apparatus according to any one of claims 1 to 3 are brought into contact with carbon nanotubes on a base material, and the plurality of blades and the base material are brought into contact with each other. A carbon nanotube peeling method characterized by including a peeling step of peeling carbon nanotubes from a base material by relative movement. A peeling step of peeling the carbon nanotubes on the substrate by the peeling device according to any one of claims 1 to 3,
And a growth step of growing the carbon nanotubes on the substrate from which the carbon nanotubes have been peeled in the peeling step.

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