JP5622278B2 - Base material for manufacturing aligned carbon nanotube aggregate, method for manufacturing aligned carbon nanotube assembly, and method for manufacturing base material for manufacturing aligned carbon nanotube assembly - Google Patents

Description

  The present invention relates to a substrate for manufacturing an aligned carbon nanotube assembly, a method for manufacturing an aligned carbon nanotube assembly, and a method for manufacturing a substrate for manufacturing an aligned carbon nanotube assembly.

  A carbon nanotube (hereinafter, also referred to as “CNT”) is a carbon structure having a structure in which a carbon sheet configured by arranging carbon atoms in a hexagonal shape in a plane is closed in a cylindrical shape. There are multi-layered and single-layered CNTs, all of which are in terms of mechanical strength, optical properties, electrical properties, thermal properties, molecular adsorption functions, etc., from electronic device materials, optical element materials, conductive materials. Development as functional materials such as functional materials is expected. Among CNTs, single-walled CNTs have electrical characteristics (very high current density), thermal characteristics (thermal conductivity comparable to diamond), optical characteristics (light emission in the optical communication band wavelength region), hydrogen storage capacity, and metals. In addition to being excellent in various properties such as catalyst supporting ability, and having both properties of a semiconductor and a metal, it has attracted attention as a material for nanoelectronic devices, nanooptical elements, energy storage bodies, and the like.

  As a method for producing an oriented CNT film, a technique described in Patent Document 1 is known as a conventional technique.

  Patent Document 1 describes producing a CNT film by producing a sol-gel porous carrier having 0.1 to 50 nm pores and decomposing a carbon compound using a catalyst supported on the carrier. ing.

JP 2004-2182 A (published January 8, 2004)

  However, the above conventional techniques are not sufficient from the viewpoint of productivity, and new carbon nanotube production techniques are required.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a substrate for manufacturing an aligned carbon nanotube assembly for manufacturing an aligned carbon nanotube assembly more efficiently.

  In order to solve the above problems, a substrate for manufacturing an aligned carbon nanotube assembly according to the present invention includes a substrate, a catalyst support layer, and a catalyst layer, and the catalyst support layer is on the substrate, and has a plate-like structure. The surface of the aluminum oxide is porous, and the catalyst layer selectively exposes at least a part of the pores on the surface where no pores are formed. It is characterized by a layer of catalyst particles.

  In the substrate for producing an aligned carbon nanotube aggregate according to the present invention, the catalyst support layer is more preferably porous.

  In the substrate for producing an aligned carbon nanotube aggregate according to the present invention, it is more preferable that the catalyst support layer has mesopores having a pore diameter of 1 to 50 nm.

  In the base material for producing an aligned carbon nanotube aggregate according to the present invention, the arithmetic mean roughness Ra of the surface is more preferably 0.05 μm or less.

  In the base material for producing an aligned carbon nanotube aggregate according to the present invention, the thickness of the catalyst supporting layer is more preferably 10 nm or more and 100 nm or less.

In the base material for producing an aligned carbon nanotube aggregate according to the present invention, the density of the catalyst particles in the catalyst layer is 1.0 × 10 ¹¹ particles / cm ² or more and 2.0 × 10 ¹² particles / cm ^2. The following is more preferable.

  In addition, the method for producing an aligned carbon nanotube aggregate according to the present invention includes the base material for manufacturing an aligned carbon nanotube assembly in which the surrounding environment of the base material for manufacturing the aligned carbon nanotube is an environment containing a raw material gas for carbon nanotubes. And a growth step in which at least one of the source gases is heated to grow an aligned carbon nanotube aggregate by chemical vapor deposition, and the base material for manufacturing the aligned carbon nanotube aggregate includes a substrate, a catalyst support layer, and a catalyst. The catalyst support layer is on the substrate and is an aluminum oxide having a plate-like structure, and the surface has pores, and the catalyst layer is on the surface and has pores. It is characterized by a layer of catalyst particles in an unoccupied location.

  In the method for producing an aligned carbon nanotube assembly according to the present invention, it is more preferable that the surrounding environment further includes a catalyst activator.

  The method for producing a substrate for manufacturing an aligned carbon nanotube assembly according to the present invention is a method for manufacturing the substrate for manufacturing an aligned carbon nanotube assembly according to the present invention, wherein the catalyst supporting layer contains an organoaluminum compound. A catalyst supporting layer forming step of applying a coating agent on a substrate and providing a catalyst supporting layer on the substrate; and a catalyst layer coating agent comprising at least one selected from the group consisting of an organometallic compound and a metal salt. And a catalyst layer forming step of applying the catalyst layer on the support layer and providing the catalyst layer on the catalyst support layer.

  In the method for producing a substrate for producing an aligned carbon nanotube assembly according to the present invention, in the catalyst supporting layer forming step, after applying the catalyst supporting layer coating agent, heating at 200 ° C. or more and 400 ° C. or less is more preferable. preferable.

  In the method for producing a base material for producing an aligned carbon nanotube aggregate according to the present invention, it is more preferable to heat in a time of 5 minutes or more and 3 hours or less.

  In the method for manufacturing a base material for manufacturing an aligned carbon nanotube assembly according to the present invention, after the catalyst layer forming step, the surrounding environment of the substrate is an environment containing a reducing gas, and at least one of the substrate and the reducing gas is used. More preferably, it further includes a formation step of heating and reducing and granulating the catalyst layer.

  According to the present invention, it is possible to produce an aligned carbon nanotube aggregate more efficiently.

It is a figure which shows typically the structure of the catalyst support layer of the base material for CNT alignment assembly manufacture which is one Embodiment of the base material for CNT alignment assembly manufacture which concerns on this invention, the structure of a catalyst layer, and a mode that CNT grows. It is a figure which shows typically the mode of the growth of CNT when producing CNT using the porous support | carrier of a prior art. FIG. 4 is a diagram showing the results of SEM observation of the surface of the catalyst support layer of Example 1. It is a figure which shows the result of having measured the BJH plot of the solid produced as a model of a catalyst support layer for BET specific surface area measurement in Example 1. FIG. In Example 1, it is a figure which shows the result of having observed the surface of the catalyst support layer after manufacturing a CNT oriented assembly once and removing this once by SEM. It is a figure which shows the result of having observed the surface of the catalyst support layer of Example 4 by SEM. In Example 4, it is a figure which shows the result of having observed the surface of the catalyst support layer after manufacturing an aligned CNT aggregate once and removing this once by SEM. 6 is a diagram showing the result of SEM observation of the surface of a catalyst support layer of Comparative Example 1. FIG.

(CNT aligned aggregate)
By the method for producing an aligned aggregate of carbon nanotubes according to the present invention (hereinafter simply referred to as the production method according to the present invention), CNTs can be grown on a substrate with high efficiency. Aligned in a specific direction to form an aligned CNT aggregate.

The single-walled aligned CNT aggregate obtained by the production method according to the present invention has a high specific surface area, each CNT is oriented in a regular direction, and has a low bulk density. It has the characteristic that it has the outstanding characteristic which is not in. Monolayer aligned CNT aggregate, the specific surface area as large as 600m ² / g~2600m ² / g. Such a large specific surface area is effective as a catalyst carrier and energy / material storage material, and is suitable for applications such as supercapacitors and actuators. In addition, each CNT constituting the aligned CNT aggregate is oriented in a regular direction. Therefore, the directionality of the function of each CNT can be aligned, and as a result, a highly functional CNT aggregate can be obtained.

Further monolayer aligned CNT aggregate, the weight density is low density ^{0.002g / cm 3 ~0.2g / cm 3} . Thus, the single-walled aligned CNT aggregates grown on the substrate at a low density are weakly linked with each other, and the single-walled aligned CNT aggregates removed from the substrate can be used as a solvent. It is easy to disperse uniformly. In addition to these, the single-walled aligned CNT aggregate of the present invention, which is moderately oriented and has a low density, can be easily adjusted in density by a post-treatment process after generation. Like a cocoon made by bundling cocoons, it is possible to fill adjacent CNTs with high density without any gaps. At this time, it can be formed into various shapes by controlling the densification process.

(Orientation)
As for the orientation evaluation method, for example, an image obtained by fast Fourier transform of an X-ray diffraction intensity, SEM image or atomic force microscope (also referred to as “AMF”) image obtained by the θ-2θ method or the Laue method. In the aligned single-walled CNT aggregate obtained by the present invention, the orientation coefficient of Hermann calculated using the intensity profile obtained from is, for example, −0.5 or more and 1 or less, preferably more than 0 and 1 or less. More preferably, it is 0.25 or more and 1 or less. Single-walled aligned CNT aggregates in such a range of orientation exhibit good electrical properties, good mechanical properties, good thermal properties, a large specific surface area, high unity, easy handling, and shape processing The property is also good. Moreover, it exhibits sufficient thermodynamic, electrical, and mechanical anisotropy and is suitable for various applications.

  On the other hand, single-walled aligned CNT aggregates whose Hermann orientation coefficient is less than 0 do not exhibit orientation. When the Herman orientation coefficient is less than 0.25, the CNT inclination is 45 °, and the orientation effect is reduced. A single-walled aligned CNT aggregate having a Herman orientation coefficient of 1 is completely aligned.

  In order for the aligned single-walled CNT aggregate to exhibit orientation and a high specific surface area, the height (length) of the aligned single-walled CNT aggregate is preferably in the range of 10 μm to 10 cm. A single-walled aligned CNT aggregate in this height range has good orientation and a large specific surface area. The orientation is improved by setting the height to 10 μm or more. Further, if the height is 10 cm or less, the production can be performed in a short time, so that adhesion of carbon impurities can be suppressed and the specific surface area can be improved. Furthermore, the single-walled aligned CNT aggregate having this height range has high integrity, is easy to handle, and has good shape workability.

The orientation of the aligned CNT aggregate can be evaluated by, for example, at least one of the following methods 1 to 3. That is,
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.

  In the above-mentioned X-ray diffraction method, (CP) diffraction peak due to packing between single-walled CNTs, (002) peak diffraction intensity, and carbon six-membered ring structure constituting single-walled CNTs (100) , (110) The intensity of diffraction peaks in the incident directions of the parallel and perpendicular peaks is also different from each other.

[Base material for producing aligned carbon nanotube assemblies]
A substrate for producing an aligned CNT aggregate according to the present invention includes a substrate, a catalyst support layer, and a catalyst layer, and the catalyst support layer is on the substrate and is a plate-shaped aluminum oxide on the surface thereof. Is perforated, and the catalyst layer is a layer of catalyst particles that is selectively exposed on at least a portion of the pores and is located on the surface in a non-porous location.

  If the base material for manufacturing an aligned CNT aggregate according to the present invention is used, CNTs can be produced more efficiently than when the porous carrier described in Patent Document 1 is used. The reason for this will be described with reference to FIGS. FIG. 1 is a diagram schematically showing the structure of a catalyst-supporting layer and a catalyst layer of a substrate for producing an aligned CNT aggregate, which is an embodiment of the substrate for producing an aligned CNT aggregate according to the present invention, and how CNT grows. It is. FIG. 2 is a diagram schematically showing the state of CNT growth when producing CNTs using the porous carrier described in Patent Document 1.

  As shown in FIG. 1, the substrate for manufacturing an aligned CNT aggregate has a catalyst-supporting layer 1-1 formed on a substrate (not shown).

  The catalyst support layer 1-1 has a plate-like structure. The catalyst support layer 1-1 is provided with a plurality of holes 1-2.

  The catalyst particles 1-4 are on the catalyst support layer 1-1, in a place where the holes 1-2 are not vacant, and a plurality of catalyst particles 1-4 form a catalyst layer.

  The CNTs 1-3 grow upward from the catalyst particles 1-4. At this time, it is considered that the raw material gas and the catalyst activator are easily absorbed by the catalyst particles 1-4 because they are adsorbed on the inner wall of the hole 1-2. Further, as in Patent Document 1, the catalyst particles 1-4 are not clogged with the inner walls of the holes 1-2 and the CNTs already grown thereon. Therefore, it is considered that the area of the catalyst particles 1-4 that can contact the raw material gas and the catalyst activation material is larger than that of the catalyst of Patent Document 1.

  On the other hand, as shown in FIG. 2, in the porous carrier 2-1 described in Patent Document 1, the catalyst 2-4 is supported in the pores 2-2. Therefore, the catalyst 2-4 is surrounded by the inner walls of the pores and the CNTs 2-3 already grown on the pores, and it is considered that the source gas or the like is difficult to contact the catalyst 2-4.

  That is, in the present invention, catalyst particles are not supported in the holes 1-2, and at least some of the holes on the surface of the catalyst support layer 1-1 are formed by, for example, the method described in Examples described later. By selectively exposing and selectively supporting the catalyst particles 1-4 in a place where there are no holes, the area of the catalyst particles 1-4 that can be in contact with the raw material gas and the catalyst activator is increased. .

  Therefore, if the substrate for manufacturing an aligned CNT aggregate according to the present invention is used, CNTs can be more efficiently manufactured because the raw material gas or the like is more likely to come into contact with the catalyst particles as compared with the conventional technique.

  In Patent Document 1, the catalyst solution (catalyst layer coating agent) is an aqueous solution, which is neutralized with ammonia water. The higher the pH, the more the catalyst is supported inside the pores (reference: Japanese Patent Laid-Open No. 60-44055). In order to manufacture the base material for manufacturing an aligned CNT aggregate according to the present invention, the catalyst layer coating agent is more preferably manufactured by manufacturing according to the manufacturing method of the base material for manufacturing an aligned CNT aggregate according to the present invention described later. By including an organic solvent, it is possible to more suitably prevent catalyst particles from being supported in the pores.

(substrate)
The substrate may be any member that can carry a CNT catalyst on its surface, and it is preferable that the shape can be maintained even at a high temperature of 400 ° C. or higher. Examples of the material include iron, nickel, chromium, molybdenum, tungsten, titanium, aluminum, manganese, cobalt, copper, silver, gold, platinum, niobium, tantalum, lead, zinc, gallium, germanium, indium, and antimony. Examples thereof include metals and alloys and oxides containing these metals, or nonmetals such as silicon, quartz, glass, mica, graphite, diamond and phosphorus, 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.

  Examples of the substrate include a flat plate shape, a thin film shape, and a block shape, and a flat plate shape is preferable.

  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 base material can be sufficiently heated in the CVD process, and CNT growth defects 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. There is no particular limitation on the size of one side of the substrate, but it is more desirable as it is larger from the viewpoint of mass productivity of CNT.

(Carburization prevention layer)
A carburization prevention layer may be formed on at least one of the front surface and the back surface of the base material, and it is desirable that the carburization prevention layer is formed on both the front surface and the back surface. This carburizing prevention layer is a protective layer for preventing the base material from being carburized and deformed in the carbon nanotube production 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, and nitrides such as aluminum nitride and silicon nitride. Among them, aluminum oxide and silicon oxide are preferable because they have a high effect of preventing carburization.

(Catalyst support layer)
The catalyst supporting layer is an aluminum oxide having a plate-like structure on the substrate. There are holes in the surface.

  The catalyst support layer may be a plate-like aluminum oxide having pores on the surface, but is more preferably porous. It can be confirmed that the catalyst-carrying layer is porous by observing pores on the surface of the catalyst-carrying layer by observation with a scanning electron microscope (SEM). Since the catalyst support layer is porous, CNT production stability is improved. Although the mechanism is not clear, it is presumed that the catalyst activation material is easily supplied to the catalyst by adsorbing the catalyst activation material to the pores existing on the surface of the catalyst support layer, and the catalyst is difficult to deactivate. The

  The size and density of the pores on the surface of the catalyst support layer are not particularly limited. For example, the pore diameter of the catalyst support layer is preferably 1 to 50 nm, more preferably 2 to 20 nm. These pore characteristics can be calculated by BJH plotting data obtained by the nitrogen gas adsorption method. By setting the diameter of the pores in the above range, it is presumed that the raw material gas and the catalyst activator can be easily adsorbed and the growth of CNT can be promoted. The ratio of the area of the pores on the surface of the catalyst support layer is preferably 5% or more and 30% or less. Within this range, the production stability of CNTs is improved without lowering the yield of CNTs. The ratio of the area of the pores can be determined from the ratio of the area of the portions (pores) that appear to be black in a circular shape to the total area of the catalyst support layer, as observed with a scanning electron microscope (SEM).

The catalyst-supporting layer preferably has a specific surface area of 300 m ² / g or more as a BET specific surface area by nitrogen adsorption. When the BET specific surface area is 300 m ² / g or more, CNTs can be grown with higher efficiency. The BET specific surface area of the catalyst supporting layer surface can be controlled by the heating temperature and heating time after applying the catalyst supporting layer coating agent described later. By setting the heating temperature and the heating time in the ranges described below, a catalyst-carrying layer having a BET specific surface area of 300 m ² / g or more can be obtained efficiently. Further, the upper limit of the BET specific surface area on the surface of the catalyst support layer is not particularly limited, but is preferably 800 m ² / g or less.

  The surface of the catalyst support layer is preferably smooth. When the surface of the catalyst supporting layer is smooth, it is possible to suppress an increase in the particle size of the catalyst fine particles when forming the catalyst layer, thereby obtaining a CNT having a large specific surface area. The arithmetic average roughness Ra of the surface of the catalyst support layer is not particularly limited, but is more preferably 0.05 μm or less, and further preferably 0.03 μm or less.

  The thickness of the catalyst support layer is preferably 10 nm or more and 100 nm or less. According to the catalyst supporting layer forming step described later, it is easy to form a uniform and uniform catalyst supporting layer within this thickness range. When the thickness is 100 nm or less, it is easy to form a homogeneous catalyst support layer without cracks. It becomes easy to generate CNTs at a film thickness of 10 nm or more.

  The catalyst support layer may be made of aluminum oxide, but preferably contains carbon atoms. The form of carbon atoms contained in the catalyst support layer may be any form. That is, a carbon compound may be included in the catalyst supporting layer, and a carbon simple substance may be included in the catalyst supporting layer. For example, when an organometallic compound containing aluminum is applied onto a substrate and heated to form a catalyst support layer, carbon atoms remain in the catalyst support layer so that carbon atoms are contained in the catalyst support layer. Can be.

  The composition ratio of carbon atoms in the catalyst support layer is preferably in the range of 8% to 30% in elemental analysis measured by X-ray electron analysis (ESCA). The lower limit of the composition ratio of carbon atoms is more preferably 10%, still more preferably 15%, and the upper limit is more preferably 25%, still more preferably 20%. Within this range, it is possible to obtain an aligned CNT aggregate that is less likely to aggregate and is excellent in dispersibility. In addition, the catalyst support layer having a carbon atom composition ratio of 30% or less can be obtained by, for example, heating an organometallic compound containing aluminum so that carbon atoms remain. Has the advantage of low.

  Regarding the content of oxygen atoms in the aluminum oxide constituting the catalyst supporting layer, for example, in the elemental analysis measured by X-ray electron analysis (ESCA), the composition ratio of oxygen atoms to aluminum atoms (O / Al) Is more preferably in the range of 1.8 to 2.7. Within this range, it is possible to obtain an aligned CNT aggregate that is less likely to aggregate and is excellent in dispersibility. Moreover, since it is easy to make the composition ratio in this range by adjusting the heating conditions of the organometallic compound containing aluminum, it is advantageous from the viewpoint of production.

(Catalyst layer)
The catalyst layer is a layer of catalyst particles provided on the surface of the catalyst support layer so as to selectively expose at least a part of the pores. In other words, the catalyst particles are on the surface of the catalyst support layer and not on the inner wall surface of the hole. When the catalyst particles are present at this location, the raw material gas and the catalyst activator can be easily supplied to the catalyst particles, and the aligned CNT aggregate can be produced more efficiently.

  Any catalyst that can catalyze the growth of CNTs may be used. For example, iron is more preferable.

  As the particle diameter of the catalyst, the maximum diameter is more preferably 30 nm or less. Further, the average diameter is more preferably 20 nm or less, and further preferably 15 nm or less. The average diameter of the catalyst fine particles can be estimated by measuring the diameter of each catalyst fine particle with an SEM image and taking the arithmetic average value. When the particle diameter of the catalyst fine particles is within the above range, the production of multi-walled CNTs can be suppressed and single-walled CNTs can be easily used as the main product.

In the catalyst layer, the density of the catalyst particles, for example, 1.0 × ^{10 11} / cm ² or more, and more preferably 2.0 × ^{10 12} / cm ² or less. If it is below this range, the density of the obtained CNTs becomes small, and the CNTs may be difficult to vertically align with the substrate. On the other hand, if it is above this range, the density of CNTs will increase, and it will be difficult for the raw material gas and the catalyst activation material to reach the catalyst fine particles in the growth process, which may inhibit the growth of CNTs.

[Manufacturing method of substrate for manufacturing aligned carbon nanotube assembly]
The method for producing a substrate for producing an aligned CNT aggregate according to the present invention includes a catalyst carrying layer forming step of applying a catalyst carrying layer coating agent containing an organoaluminum compound on a substrate and providing the catalyst carrying layer on the substrate; And a catalyst layer forming step of applying a catalyst layer coating agent containing at least one selected from the group consisting of an organic metal compound and a metal salt on the catalyst support layer and providing the catalyst layer on the catalyst support layer.

  As a result, a catalyst support layer having a plate structure with holes can be formed. In addition, the catalyst layer can be formed by forming catalyst particles on the surface of the catalyst support layer where no pores are formed. That is, the above-mentioned base material for producing an aligned CNT aggregate according to the present invention can be formed.

(Catalyst support layer forming process)
In the catalyst supporting layer forming step, a catalyst supporting layer coating agent containing an organoaluminum compound is applied on the substrate, and the catalyst supporting layer is provided on the substrate. When the catalyst-carrying layer coating agent is applied on the substrate, a catalyst-carrying layer is formed on the substrate. Moreover, it is good to heat after apply | coating. The catalyst-supporting layer makes it easy to control the particle size of the catalyst to be supported, and makes it difficult for sintering to occur at high temperatures even when catalyst fine particles are present. Moreover, it has a role which improves the activity of a catalyst.

(Organic aluminum compound)
The catalyst support layer coating agent may contain an organoaluminum compound. This is because the organoaluminum compound contains carbon atoms in advance, and a substrate containing aluminum atoms and carbon atoms can be easily produced in the catalyst support layer.

  The organoaluminum compound is preferably thermally decomposed at a temperature of 50 ° C. or higher and 350 ° C. or lower. If the thermal decomposition temperature is 50 ° C. or higher, the stability as a coating agent can be maintained. If the thermal decomposition temperature is 350 ° C. or lower, a high temperature is not required, so that the heating temperature at which CNT growth is most favorable can be achieved in the heating step described later.

  An alkoxide is mentioned as an organoaluminum compound. More specifically, aluminum trimethoxide, aluminum triethoxide, aluminum tri-n-propoxide, aluminum tri-i-propoxide, aluminum tri-n-butoxide, aluminum tri-sec-butoxide, aluminum tri-tert -Butoxide etc. are mentioned. These can be used alone or as a mixture. Other examples of the organoaluminum compound include complexes such as tris (acetylacetonato) aluminum (III). Among these, it is preferable to use aluminum alkoxide because wettability to a metal substrate is good and the growth of carbon nanotubes is good.

(Organic solvent)
In the catalyst carrying layer coating agent, for example, an organoaluminum compound may be dissolved in an organic solvent. As the organic solvent, various organic solvents such as alcohols, glycols, ketones, ethers, esters, hydrocarbons and the like can be used, but it is preferable to use alcohols or glycols because the solubility of the organoaluminum compound is good. These organic solvents may be used alone or in combination of two or more.

  Examples of the alcohol include methanol, ethanol, isopropyl alcohol, n-butanol, isobutanol, octanol, and n-propyl alcohol. As glycols, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol mono n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol Examples thereof include monoethyl ether, propylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate and the like. Among the alcohols, methanol, ethanol, isopropyl alcohol, and the like are preferable in terms of handleability and storage stability.

  When the organoaluminum compound is difficult to dissolve in alcohol or glycol, other solvents such as hydrocarbons can be used in combination.

(Stabilizer)
More preferably, the catalyst-carrying layer coating agent contains a stabilizer for suppressing the condensation polymerization reaction of the organoaluminum compound.

  The stabilizer is not particularly limited as long as it suppresses the condensation polymerization reaction of the organoaluminum compound, but is preferably at least one selected from the group consisting of β-diketone and alkanolamine. These compounds may be used alone or in combination of two or more. By adding such a stabilizer, an active reactive group that causes a condensation polymerization reaction is capped by the stabilizer, so that the condensation polymerization reaction does not proceed and a coating agent with little viscosity change over a long period of time can be obtained. In addition, since the degree of polymerization of the polymer oxide can be controlled, it is possible to obtain a coating agent that is stable over a long period of time without causing precipitation of metal oxide due to the generation of particles having a high molecular weight and a large particle size. . Using the same catalyst-supporting layer coating agent over a long period of time, it becomes possible to stably produce CNTs of the same quality. If the stabilizer is not blended, for example, the quality of the synthesized CNT may change between the solution immediately after preparation and the solution after storage for 1 month.

  According to the present invention, the condensation polymerization reaction does not proceed and the solification does not proceed, or the state of the solification can be controlled, so that large particles are not generated in the liquid. Therefore, it is possible to form a flat and uniform catalyst support layer. In addition, the catalyst particles can be controlled to an optimum state.

  As the solification of the organoaluminum compound proceeds, the thickness of the catalyst support layer becomes non-uniform, the catalyst particle size increases, and as a result, multi-walled CNTs are easily generated. Since the multi-walled CNT has a small specific surface area, an aligned CNT aggregate having a large specific surface area cannot be obtained.

  In addition, the present invention is capable of forming a catalyst-carrying layer having a uniform film thickness by preventing agglomeration of organoaluminum compounds when coated on a substrate by blending a stabilizer with a solution of the organoaluminum compound. They found out. At the same time, the present inventors have found that there is a role of improving the wettability to the metal substrate, and it is possible to form a catalyst supporting layer having a uniform film thickness by preventing application failure such as repellency.

  Examples of β-diketones used as stabilizers include acetylacetone, methyl acetoacetate, ethyl acetoacetate, benzoylacetone, dibenzoylmethane, benzoyltrifluoroacetone, furoylacetone, and trifluoroacetylacetone. It is preferable to use ethyl acetoacetate.

  Examples of alkanolamines used as stabilizers include monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N.I. N-dimethylaminoethanol, diisopropanolamine, triisopropanolamine and the like. Among these, a secondary or tertiary alkanolamine is preferable because wettability to a metal substrate is improved and CNT growth is improved.

  The stabilizer is preferably one that thermally decomposes or volatilizes at a temperature of 50 ° C. or higher and 350 ° C. or lower. If the thermal decomposition temperature or boiling point is 50 ° C. or higher, the stability as a coating agent can be maintained. When the thermal decomposition temperature or boiling point is 350 ° C. or lower, when performing the heating step described later, the growth of CNTs can be made to the most favorable heating temperature, and productivity is improved because a high temperature is not required. By having a pyrolysis temperature or boiling point lower than the temperature in the heating step described later, the amount remaining in the film after the heating step can be reduced, and defective growth of CNTs can be suppressed.

  The compounding molar ratio of the organoaluminum compound and the stabilizer contained in the catalyst-carrying layer coating agent is not particularly limited, but in the range of 1: 0.01 to 3.0 with respect to the number of moles of the organoaluminum compound. When added, an excellent effect appears, and it is particularly preferable to add in the range of 1: 0.5 or more and 1.5 or less with respect to the number of moles of the organoaluminum compound. If the added amount of the stabilizer is 0.01 or more with respect to the organoaluminum compound, the stabilizing function is sufficiently exhibited, and if it is 3.0 or less, adverse effects such as whitening of the film can be suppressed. By adjusting the compounding molar ratio of the organoaluminum compound and the stabilizer, it is possible to more reliably prevent the hydrolysis and condensation reaction of the organoaluminum compound from starting before the heating step, and under the subsequent heating step conditions. It is possible to adjust the hydrolysis and condensation reaction of

  The amount of the organoaluminum compound contained in the catalyst-carrying layer coating agent is in the range of 0.5 wt% or more and 10 wt% or less because the film thickness unevenness when applied and the smoothness of the surface are excellent. It is preferable that the range be 0.5 wt% or more and 5 wt% or less.

  In the catalyst support layer coating agent, the water content with respect to the total amount of the coating agent is preferably 2.0% or less. When the water content is 2.0% or less, it is possible to suppress the progress of aggregation and sol formation of the organoaluminum compound in the coating agent. When the aggregation and solification of the organoaluminum compound proceeds, large-sized fine particles are likely to be generated in the liquid, which may reduce the specific surface area of the CNT. Further, the condensation reaction proceeds gradually, it is difficult to maintain a uniform sol state for a long time, and it becomes difficult to stably obtain the same quality CNT.

(Application)
By applying the catalyst carrying layer coating agent, a film containing an organoaluminum compound is formed on the substrate, and a catalyst carrying layer is obtained.

  The condensation polymerization reaction of the organoaluminum compound may be accelerated by moisture present in the atmosphere. Therefore, controlling the temperature and humidity during coating and drying is important in producing a uniform film. As application | coating and drying conditions, it is more preferable that they are 20 degreeC or more and 25 degrees C or less and 60% or less of relative humidity. When the relative humidity is 60% or less, the reaction between the organoaluminum compound and water vapor in the atmosphere can be suppressed, and the applied film can be made more uniform.

  As a method for applying the coating agent to the substrate surface, any method such as a method of applying by spraying, brush coating, spin coating, dip coating or the like may be used.

(Heating process)
More preferably, the method for producing a substrate for producing an aligned CNT aggregate according to the present invention includes a heating step of heating the substrate after the catalyst-carrying layer coating agent is applied on the substrate. By heating the substrate on which the catalyst-carrying layer coating agent is applied, hydrolysis and polycondensation reaction of the organoaluminum compound is started, and a cured film containing the organoaluminum compound is formed on the substrate surface.

  Moreover, an aluminum oxide thin film is formed by heating. Aluminum oxide (alumina) is preferably amorphous alumina because CNT grows well. Alternatively, transition alumina such as α-alumina, γ-alumina, δ-alumina, χ-alumina, κ-alumina, θ-alumina, and ρ-alumina may be contained.

  After applying the catalyst-carrying layer coating agent, it is preferable to dry it, and then a heating step is preferably performed. The adhesion between the substrate and the catalyst support layer is improved, and the stability of coating when the catalyst layer coating agent is applied in the next step is improved.

  The heating temperature is more preferably 200 ° C. or more and 400 ° C. or less, and further preferably 250 ° C. or more and 350 ° C. or less. Usually, the baking of the organoaluminum compound requires a high temperature of 500 ° C. to 1200 ° C., but in the present invention, since it is carried out at a low temperature, the productivity is excellent. When heating temperature is 400 degrees C or less, it suppresses that the crystallinity of an aluminum oxide film becomes high. Further, carbon atoms contained in the organoaluminum compound can be left in the catalyst support layer. As a result, it is possible to form a catalyst that is optimal for producing an aligned CNT aggregate having a large average outer diameter (2 nm or more) and a wide outer diameter distribution range (half-value width of 1 nm or more). If the crystallinity of the aluminum oxide film becomes high, the catalyst fine particles cannot be brought into an optimum state, and the activity as the catalyst support layer and the catalyst becomes small, and the CNT growth may be deteriorated. In addition, when a metal substrate is used, the heating temperature is 400 ° C. or lower, so that the oxidation of the substrate surface can be prevented and deterioration of CNT growth can be prevented.

  The heating time is preferably as short as possible from the viewpoint of suppressing the crystallinity of the aluminum oxide film from becoming high, from the viewpoint of remaining carbon atoms contained in the organoaluminum compound in the catalyst support layer, and from the viewpoint of production efficiency. More preferably, it is 5 minutes or more and 3 hours or less. The upper limit of the heating time is more preferably 1 hour, particularly preferably 30 minutes.

  The film thickness of the catalyst support layer after the heating step is more preferably 10 nm or more and 100 nm or less. It is easy to form a uniform and uniform catalyst support layer within this thickness range. In a film thickness of 100 nm or less, it is easy to form a homogeneous catalyst support layer without cracks. It becomes easy to generate CNTs at a film thickness of 10 nm or more.

(Catalyst layer formation process)
In the catalyst layer forming step, a catalyst layer coating agent containing at least one selected from the group consisting of an organometallic compound and a metal salt is applied on the catalyst support layer, and the catalyst layer is provided on the catalyst support layer.

  A catalyst layer is formed on the catalyst support layer by applying the catalyst layer coating agent on the catalyst support layer. It is more preferable to dry after application. Moreover, it is more preferable to perform the formation process mentioned later after forming a catalyst layer. Thereby, the catalyst of the catalyst layer is reduced and finely divided, and functions more suitably as a catalyst for CNT generation. In addition, by finely applying the catalyst layer coating agent in this way, the catalyst support layer is prevented from clogging the pores of the catalyst support layer and the catalyst particles are uniformly formed around the pores. It is speculated that you can. The fine particles of the catalyst formed by the method for producing a base material for producing an aligned CNT aggregate according to the present invention have a wide diameter distribution and a fine particle density on the substrate, so that the outer diameter distribution of the CNT is wide, Furthermore, it is presumed that CNTs with many bending points can be obtained. As a result, compared to conventional CNTs, it is difficult for CNTs to form a strong bundle and it is possible to produce CNTs with excellent dispersibility.

(Organic metal compounds, metal salts)
The catalyst layer coating agent contains at least one selected from the group consisting of an organometallic compound and a metal salt. When these compounds are subjected to the heating step described later, they change to metal hydroxides or metal oxides on the catalyst support layer. The organometallic compound and the metal salt are preferably thermally decomposed at a temperature of 50 ° C. or higher and 350 ° C. or lower. If the thermal decomposition temperature is 50 ° C. or higher, the stability as a coating agent can be maintained. When the thermal decomposition temperature is 350 ° C. or lower, the heating temperature most suitable for the growth of CNTs can be achieved in the heating step described later, and productivity is improved without requiring a high temperature.

  As the metal constituting the organometallic compound or metal salt for forming the catalyst layer, it is preferable that iron is contained since the growth of CNTs is remarkably improved.

  Examples of the organometallic compound containing iron include iron pentacarbonyl, ferrocene, acetylacetone iron (II), acetylacetone iron (III), trifluoroacetylacetone iron (II), and trifluoroacetylacetone iron (III).

  Examples of the metal salt containing iron include inorganic acid irons such as iron sulfate, iron nitrate, iron phosphate, iron chloride, and iron bromide, and organic acid irons such as iron acetate, iron oxalate, iron citrate, and iron lactate. Etc. You may mix 1 type, or 2 or more types of compounds.

  Among these, it is preferable to use organic acid iron because wettability to a metal substrate is good and CNT growth is good.

(Organic solvent)
In the catalyst layer coating agent, for example, at least one selected from the group consisting of an organometallic compound and a metal salt may be dissolved in an organic solvent. Various organic solvents such as alcohols, glycols, ketones, ethers, esters, hydrocarbons and the like can be used, but alcohols or glycols are preferably used because of the good solubility of organometallic compounds and metal salts. These organic solvents may be used alone or in combination of two or more.

  Examples of the alcohol include methanol, ethanol, isopropyl alcohol, n-butanol, isobutanol, octanol, and n-propyl alcohol. As glycols, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol mono n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol Examples thereof include monoethyl ether, propylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate and the like. Among the alcohols, methanol, ethanol, isopropyl alcohol, and the like are preferable in terms of handleability and storage stability.

(Stabilizer)
More preferably, the catalyst layer coating agent includes a stabilizer for suppressing at least one condensation polymerization reaction selected from the group consisting of an organometallic compound and a metal salt.

  The stabilizer is not particularly limited as long as it suppresses the condensation polymerization reaction of the organometallic compound and the metal salt, but is preferably at least one selected from the group consisting of β-diketone and alkanolamine. These compounds may be used alone or in combination of two or more. By adding such a stabilizer, an active reactive group that causes a condensation polymerization reaction is capped by the stabilizer, so that the condensation polymerization reaction does not proceed and a coating agent with little viscosity change over a long period of time can be obtained. In addition, since the degree of polymerization of the polymer oxide can be controlled, it is possible to obtain a coating agent that is stable over a long period of time without causing precipitation of metal oxide due to the generation of particles having a high molecular weight and a large particle size. . By using the same catalyst layer coating agent over a long period of time, it becomes possible to stably produce CNTs of the same quality. If the stabilizer is not blended, for example, the quality of the synthesized CNT may change between the solution immediately after preparation and the solution after storage for 1 month.

  According to the present invention, the condensation polymerization reaction does not proceed and the solification does not proceed, or the state of the solification can be controlled, so that large particles are not generated in the liquid. Therefore, it is possible to form a flat and uniform catalyst layer. In addition, the catalyst particles can be controlled to an optimum state.

  When the solification of the organometallic compound and the metal salt proceeds, the catalyst becomes non-uniform in film thickness, the catalyst particle size increases, and as a result, multi-walled CNTs are easily generated. Since the multi-walled CNT has a small specific surface area, an aligned CNT aggregate having a large specific surface area cannot be obtained.

  In addition, by adding a stabilizer to the solution of the organometallic compound and / or metal salt, the organometallic compound and the metal salt are prevented from aggregating with each other when coated on the catalyst support layer. It is possible to form a catalyst layer.

  Examples of β-diketones used as stabilizers include acetylacetone, methyl acetoacetate, ethyl acetoacetate, benzoylacetone, dibenzoylmethane, benzoyltrifluoroacetone, furoylacetone, and trifluoroacetylacetone. It is preferable to use ethyl acetoacetate.

  Examples of alkanolamines used as stabilizers include monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N.I. N-dimethylaminoethanol, diisopropanolamine, triisopropanolamine and the like. Among these, a secondary or tertiary amine is preferable because the growth of CNT is improved.

  The stabilizer is preferably one that thermally decomposes or volatilizes at a temperature of 50 ° C. or higher and 350 ° C. or lower. If the thermal decomposition temperature or boiling point is 50 ° C. or higher, the stability as a coating agent can be maintained. If the thermal decomposition temperature or boiling point is 350 ° C. or lower, when the heating step described later is performed, the heating temperature most suitable for the growth of CNT can be achieved, and productivity is improved because a high temperature is not required. By having a pyrolysis temperature or boiling point lower than the temperature in the heating step described later, the amount remaining in the film after the heating step can be reduced, and defective growth of CNTs can be suppressed.

  The compounding molar ratio of the total amount of the organometallic compound and metal salt contained in the catalyst layer coating agent and the stabilizer is not particularly limited, but is 1: 0.01 or more with respect to the number of moles of the organometallic compound and metal salt. When it is added in the range of 3.0 or less, a more excellent effect appears. In particular, it is preferably added in the range of 1: 0.5 or more and 1.5 or less with respect to the number of moles of the organometallic compound and the metal salt. . If the added amount of the stabilizer is 0.01 or more relative to the total amount of the organometallic compound and the metal salt, the stabilizing function is sufficiently exerted, and if it is 3.0 or less, adverse effects such as whitening of the film are suppressed. can do. By adjusting the mixing molar ratio of the total amount of the organometallic compound and metal salt and the stabilizer, it is possible to reliably prevent the hydrolysis and condensation reaction of the organometallic compound or metal salt from starting before the heating step, It becomes possible to adjust the hydrolysis and condensation reaction under the subsequent heating process conditions.

  The total amount of the organometallic compound and metal salt contained in the catalyst layer coating agent reduces the unevenness of the film thickness when applied and has excellent surface smoothness. It is preferable to set it as the range of 0.1 weight% or more and 0.5 weight% or less.

(Application)
By applying the catalyst layer coating agent, a film containing an organometallic compound and / or metal salt and a stabilizer is formed on the substrate to form a catalyst layer.

  In some cases, the condensation polymerization reaction of the organometallic compound and the metal salt is accelerated by moisture present in the atmosphere. Therefore, controlling the temperature and humidity during coating and drying is important in producing a uniform film. As application | coating and drying conditions, it is preferable that they are 20 degreeC or more and 25 degrees C or less and 60% or less of relative humidity. When the relative humidity is 60% or less, the reaction between the organometallic compound and the metal salt and water vapor in the atmosphere can be suppressed, and the applied film can be made more uniform.

  In the catalyst layer coating agent, the water content with respect to the total amount of the coating agent is preferably 2.0% or less. When the water content is 2.0% or less, it is possible to suppress the progress of aggregation and solification of the organometallic compound or metal salt in the coating agent. When aggregation or solification of the organometallic compound or metal salt proceeds, fine particles having a large size are likely to be generated in the liquid, so that the specific surface area of the CNT may be reduced. Further, the condensation reaction proceeds gradually, it is difficult to maintain a uniform sol state for a long time, and it becomes difficult to stably obtain the same quality CNT.

  As a method for applying the coating agent to the substrate surface, any method such as a method of applying by spraying, brush coating, spin coating, dip coating or the like may be used.

  According to the present invention, since the catalyst can be disposed on the substrate by a coating method, the area can be increased, the scalability is excellent, and the cost can be reduced as compared with a method in which a metal thin film is disposed using a sputtering apparatus. Aligned CNT aggregates can be provided.

(Heating process)
In the catalyst layer forming step, it is preferable to perform a heating step in order to remove the organic solvent remaining in the layer. The heating temperature is preferably 50 ° C. or higher and 200 ° C. or lower. Since the heating temperature is a low temperature of 200 ° C. or lower, the hydrolysis and polycondensation reaction of the catalyst layer does not need to proceed at this point. The temperature of the catalyst layer heating step, which is performed before the formation step described later, can be performed at a low temperature of 200 ° C. or less, and is excellent in productivity.

  The heating time is preferably as short as possible from the viewpoint of suppressing the increase in crystallinity of the metal oxide film and from the viewpoint of production efficiency, and is preferably 5 minutes or longer and 30 minutes or shorter.

  The film thickness of the catalyst after the heating step is preferably 1 nm or more and 10 nm or less, and more preferably 2 nm or more and 6 nm or less. When the thickness is 2 nm or more and 6 nm or less, a single-walled aligned CNT aggregate is obtained.

(Formation process)
In the method for producing a substrate for producing an aligned CNT aggregate according to the present invention, the formation step is performed after the step of providing the catalyst layer on the catalyst support layer, more preferably after the heating step in the catalyst layer forming step. Is more preferable.

  The formation process means a process of heating the substrate and / or the reducing gas while making the environment surrounding the catalyst supported on the substrate an environment containing the reducing gas. By this step, at least one of the effects of reduction of the catalyst, promotion of atomization suitable for the growth of the 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 production of multi-walled carbon nanotubes can be suppressed. During the formation process, hydrolysis and polycondensation reaction of the catalyst layer is started, and a cured film containing a metal hydroxide and / or metal oxide is formed on the substrate surface. At the same time or after, a catalyst that is the main purpose of the formation process It is preferable to perform reduction and micronization.

  For example, when the catalyst is iron, an iron hydroxide thin film or an iron oxide thin film is formed, and at the same time or thereafter, reduction and fine particle formation occur to form iron fine particles. Further, for example, when the metal of the catalyst support layer is alumina and the catalyst metal is iron, the iron catalyst layer is reduced to form fine particles, and a large number of nanometer-size iron fine particles are formed on the alumina layer. As a result, the catalyst is prepared as a catalyst suitable for production of aligned CNT aggregates.

(Reducing gas)
The reducing gas is generally in the form of a gas at the growth temperature of CNT, which has at least one of the following effects: reduction of the catalyst, promotion of atomization that is suitable for the growth of the catalyst CNT, and improvement of the activity of the catalyst. Gas. Any suitable material can be used as long as it can produce CNTs. Typically, it is a gas having a reducing property. For example, hydrogen gas, ammonia, water vapor, and a mixed gas thereof can be applied. it can. Alternatively, a mixed gas obtained by mixing hydrogen gas with an inert gas such as helium gas, argon gas, or nitrogen gas may be used. The reducing gas is generally used in the formation process, but may be appropriately used in a growth process described later.

[Method for producing aligned carbon nanotube assembly]
In the method for producing an aligned CNT aggregate according to the present invention, the surrounding environment of the aligned CNT aggregate manufacturing substrate is an environment containing the CNT source gas, and the CNT aligned aggregate manufacturing substrate and the source gas are included. Including a growth step in which at least one is heated to grow an aligned CNT aggregate by a chemical vapor deposition (CVD) method, and the substrate for manufacturing an aligned CNT aggregate includes a substrate, a catalyst support layer, and a catalyst layer, The catalyst support layer is on the substrate and is a plate-like aluminum oxide, and the surface thereof has holes, and the catalyst layer is on the surface and has no holes. A layer of catalyst particles.

(Growth process)
In the growth step, the surrounding environment of the substrate for manufacturing an aligned CNT aggregate is set to an environment containing a raw material gas for CNT, and at least one of the base material for manufacturing an aligned CNT aggregate and the source gas is heated to form a CVD method. To grow the aligned CNT aggregate.

  For example, a substrate with a catalyst support layer and a catalyst layer is placed in a CVD furnace, and after supplying the source gas or while supplying the source gas of CNT, grow the aligned CNT aggregate on the substrate by the CVD method You can do it.

  The raw material gas may be any material that is a raw material for CNT, and is, for example, a gas having a raw carbon source at the growth temperature. Of these, hydrocarbons such as methane, ethane, ethylene, propane, butane, pentane, hexane, heptanepropylene, and acetylene are preferable. In addition, lower alcohols such as methanol and ethanol may be used. Mixtures of these can also be used. The source gas may be diluted with an inert gas.

  The inert gas may be any gas that is inert at the temperature at which CNT grows, does not reduce the activity of the catalyst, and does not react with the growing carbon nanotubes. For example, what can be used for the production of CNTs may be used as appropriate, and helium, argon, nitrogen, neon, krypton, and the like, and mixed gas thereof can be exemplified, particularly nitrogen, helium, argon, and a mixture thereof. Gas is preferred.

  In heating at least one of the base material for manufacturing an aligned CNT aggregate and the source gas, it is more preferable to heat both. The heating temperature may be any temperature at which CNT can grow, but is preferably 400 ° C. or higher and 1100 ° C. or lower. The effect of the catalyst activator described later is well expressed at 400 ° C. or higher, and the reaction of the catalyst activator with CNT can be suppressed at 1100 ° C. or lower.

(Catalyst activation material)
In the CNT growth step, the ambient environment in which the CNT growth reaction is performed more preferably further includes a catalyst activation material. By adding a catalyst activator to the surrounding environment, the production efficiency and purity of CNTs can be further improved. The catalyst activation material is, for example, a material containing oxygen, and is preferably a material that does not significantly damage CNT at the growth temperature of CNT. In addition to water vapor, for example, hydrogen sulfide, oxygen, ozone, acidic gas , Low carbon number oxygen-containing compounds such as nitrogen oxide, carbon monoxide and carbon dioxide, alcohols such as ethanol and methanol, ethers such as tetrahydrofuran, ketones such as acetone, aldehydes, esters, nitrogen oxides, Mixtures of these are also effective. Among these, water vapor, oxygen, carbon dioxide, carbon monoxide, and ethers are preferable, and water vapor is particularly preferable.

  There is no particular limitation on the amount of the catalyst activator added. For example, in the case of water vapor, the amount is preferably 10 ppm to 10000 ppm, more preferably 50 ppm to 1000 ppm, and still more preferably 200 ppm to 700 ppm. It is good to do.

  The function mechanism of the catalyst activator is presumed as follows at present. During the CNT growth process, if amorphous carbon, graphite, or the like generated as a secondary material adheres to the catalyst, the catalyst is deactivated and the growth of the CNT is inhibited. However, in the presence of a catalyst activator, amorphous carbon and graphite are gasified by oxidizing them to carbon monoxide, carbon dioxide, etc., so the catalyst layer is cleaned, increasing the activity of the catalyst and extending the active life. It is thought that the action (catalyst activation action) appears.

  As a result of the addition of the catalyst activator, the activity of the catalyst is increased and the life is extended. In the case of the conventional technique, the growth of CNTs that can be completed in about 2 minutes is continued for several tens of minutes. Compared to technology, it increases more than 100 times and even 1000 times. As a result, an aligned CNT aggregate whose height is remarkably increased is obtained.

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

(Specific surface area measurement)
The specific surface area is a value measured by the Brunauer, Emmett, and Teller method from an adsorption / desorption isotherm of liquid nitrogen measured at 77K. The specific surface area was measured using a specific surface area measuring apparatus (Bersorp mini II manufactured by Nippon Bell Co., Ltd.).

(G / D ratio)
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.

  In this example, using a microscopic laser Raman system (Nicolet Almega XR manufactured by Thermo Fisher Scientific Co., Ltd.), part of the aligned CNT aggregate near the center of the base material was peeled off from the base material of the aligned CNT aggregate. A laser was applied to the peeled surface, a Raman spectrum was measured, and a G / D ratio was obtained.

(Average outer diameter of CNT)
The CNTs were observed with a transmission electron microscope, the outer diameters of 50 CNTs were measured from the obtained images, and the arithmetic average value was taken as the average outer diameter.

(Carbon purity)
Carbon purity was measured by using a thermogravimetric analyzer (TG) to raise the temperature of CNTs to 1800C / min in air up to 800 ° C (weight reduced by burning to reach 800 ° C / initial weight) x 100 was defined as carbon purity (%).

(Scanning electron microscope analysis)
The pores of the catalyst support layer were observed using an extremely low acceleration voltage SEM (ULTRA 55 manufactured by ZEISS).

(Arithmetic mean roughness)
Arithmetic mean roughness Ra was measured with a laser microscope (VK-9700 manufactured by KEYENCE) at an objective magnification of 50 times.

(Catalyst fine particle density)
An arbitrary 100 nm square region was selected in the image obtained by SEM observation, and the number of catalyst fine particles in the region was counted. The number of catalysts per 100 nm square obtained was multiplied by 10 ¹⁰ to convert to the number of catalysts per cm ² . The same operation was performed in five regions, and the arithmetic average was taken as the catalyst fine particle density.

[Example 1]
1.9 g of aluminum tri-sec-butoxide was dissolved in 100 ml of 2-propanol. Further, 0.9 g of triisopropanolamine as a stabilizer was added and dissolved to prepare a catalyst-supporting layer coating agent.

  Separately, 174 mg of iron acetate was dissolved in 100 ml of 2-propanol. Further, 190 mg of triisopropanolamine as a stabilizer was added and dissolved to prepare a catalyst layer coating agent.

  As a substrate, a Fe—Cr alloy SUS430 (manufactured by JFE Steel Co., Ltd., Cr 18%) having a size of 40 mm × 100 mm and a thickness of 0.3 mm was used. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra≈0.063 μm.

  The above-mentioned catalyst supporting layer coating agent was applied on the substrate by dip coating in an environment of room temperature of 25 ° C. and relative humidity of 50%. As coating conditions, the substrate was dipped and held for 20 seconds, and the substrate was pulled up at a pulling rate of 10 mm / sec. Thereafter, it was air-dried for 5 minutes.

  Next, it heated for 30 minutes in 300 degreeC air environment. After heating, it was cooled to room temperature. As a result, a catalyst support layer having a thickness of 40 nm was formed on the substrate. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra was approximately 0.050 μm.

  SEM observation of the surface of the obtained catalyst support layer was performed. The results are shown in FIG. FIG. 3 is a diagram showing the result of SEM observation of the surface of the catalyst support layer of this example. As shown in FIG. 3, it was observed that the surface of the catalyst-carrying layer had pores (black portions of the image), and it was confirmed to have a porous structure.

The catalyst-carrying layer was thin and could not obtain a weight sufficient for measuring the BET specific surface area. Therefore, the following measurements were performed on the porosity of the catalyst support layer. 1.0 ml of the above catalyst-carrying layer coating agent was dropped on a glass plate and then air-dried for 5 minutes. Next, after heating for 30 minutes in an air environment of 300 ° C., the mixture was cooled to room temperature. The BET specific surface area of the solid obtained on the glass plate was 450 m ² / g. Moreover, the result of having measured the BJH plot is shown in FIG. FIG. 4 is a diagram showing a result of measuring a BJH plot of a solid produced as a model of the catalyst support layer for measuring the BET surface area in this example. It has mesopores of 2 to 20 nm with a pore diameter of 4 to 6 nm as the center, and coincided with the pore diameter estimated from the SEM image of FIG. The solid obtained here has the same type of catalyst-supporting layer coating agent and heating conditions as when the catalyst-supporting layer obtained in this example was formed. Therefore, the solid is estimated to have a BET specific surface area comparable to that of the catalyst support layer obtained in this example.

  Next, the above-mentioned catalyst layer coating agent was applied by dip coating on the catalyst support layer of the substrate in an environment of room temperature of 25 ° C. and relative humidity of 50%. As application conditions, after dipping the substrate, the substrate was held for 20 seconds, and the substrate was pulled up at a lifting speed of 3 mm / sec. Thereafter, it was air-dried for 5 minutes.

  Next, it heated for 30 minutes in 100 degreeC air environment. After heating, the mixture was cooled to room temperature to form a catalyst layer having a thickness of 3 nm.

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 5 minutes. 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 oriented single-walled CNTs was obtained.

The properties of the aligned single-walled CNT aggregate were as follows: production 1.4 mg / cm ² , G / D ratio 4.0, density: 0.030 g / cm ³ , BET-specific surface area: 1100 m ² / g, CNT Outer diameter: 0.8-8.0 nm, CNT average outer diameter 2.8 nm, carbon purity 99.9%. The average height of the aligned CNT aggregate calculated from the production amount and density is 470 μm.

The aligned CNT aggregate was peeled from the substrate, and the substrate surface was washed with a non-woven cloth soaked with ethanol. SEM observation of the substrate surface after washing was performed. The results are shown in FIG. FIG. 5 is a diagram showing the results of SEM observation of the surface of the catalyst-supporting layer after the CNT aligned aggregate was once manufactured and removed in this example. It was observed that catalyst fine particles were generated on the entire surface, and no catalyst fine particles were formed in the pores. As a result of selecting five arbitrary 100 nm square regions in the image and calculating the density of the catalyst fine particles in each region and taking the arithmetic average, the density of the catalyst fine particles is 7.8 × 10 ¹¹ particles / cm ² . there were. Further, the ratio of the area of the pores determined as the ratio of the area (pores) that looked black in the image to the total area of the catalyst supporting layer was 9%.

Preparation of a base material similar to the method described so far and production of an aligned CNT aggregate by a CVD method were performed on 30 substrates, and stability was evaluated. As a result of the growth failure when the production amount was 0.4 mg / cm ² or less, growth failure (7%) occurred in 2 out of 30 substrates.

  Table 1 summarizes the materials and the like of the catalyst support layer in this example, Example 4 described later, and Comparative Examples 1 to 3.

[Examples 2 and 3]
In the preparation of the catalyst support layer coating agent, the amounts of aluminum tri-sec-butoxide and triisopropanolamine were changed to 1/2 times and 2 times the amount of Example 1, and dissolved in 100 ml of 2-propanol. Four types of catalyst-supporting layer coating agents with different concentrations were prepared. An aligned CNT aggregate was produced in the same manner as in Example 1 except that each catalyst-supporting layer coating agent was used. The film thicknesses of the catalyst support layers formed in Examples 2 and 3 were 20 nm and 80 nm, respectively. The yield of the aligned CNT aggregate, in Example 2 (film thickness 20 nm), 1.0 mg / cm ^2, in Example 3 (film thickness 80 nm), was 1.0 mg / cm ^2, and the good growth.

[Example 4]
As a substrate, a Fe—Cr alloy SUS430 (manufactured by JFE Steel Co., Ltd., Cr 18%) having a size of 40 mm × 100 mm and a thickness of 0.3 mm was used. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra≈0.063 μm. The surface of this substrate was polished using # 1500 polishing paper. Thereafter, finish polishing was performed with a polishing solution of # 4800. The arithmetic average roughness Ra after surface polishing was Ra≈0.014 μm.

  On the substrate whose surface was polished, a catalyst support layer was produced in the same manner as in Example 1. The film thickness was 40 nm, and the arithmetic average roughness Ra was 0.020 μm.

  SEM observation of the surface of the obtained catalyst support layer was performed. The results are shown in FIG. FIG. 6 is a diagram showing the results of SEM observation of the surface of the catalyst support layer of this example. As shown in FIG. 6, it was observed that the surface had pores (black portions of the image), and the porous structure was confirmed.

  In FIG. 6 and FIG. 7 described later, the magnification at the time of observation is 100,000 times, and in FIGS. 3, 5, and 8, the magnification at the time of observation is 150,000 times. The pores appear smaller than in FIGS.

  Next, in the same manner as in Example 1, a catalyst layer was produced on the catalyst support layer, and a formation process was performed.

CVD was performed using the obtained base material to synthesize an aligned CNT aggregate. The characteristics of the obtained single-walled aligned CNT aggregate were as follows: production amount 1.6 mg / cm ² , G / D ratio 4.0, density: 0.030 g / cm ³ , BET-specific surface area: 1100 m ² / g, CNT Outer diameter: 0.8-8.0 nm, CNT average outer diameter 2.8 nm, carbon purity 99.9%. There was a tendency that the production amount was improved as compared with Example 1. The average height of the aligned CNT aggregate calculated from the production amount and density is 530 μm.

The aligned CNT aggregate was peeled from the substrate, and the substrate surface was washed with a non-woven cloth soaked with ethanol. SEM observation of the surface after washing was performed. The results are shown in FIG. FIG. 7 is a diagram showing the result of SEM observation of the surface of the catalyst-supporting layer after the CNT aligned aggregate is once manufactured and removed in this example. It was observed that catalyst fine particles were generated on the entire surface and no catalyst fine particles were formed in the pores. As a result of selecting five arbitrary 100 nm square regions in the image and calculating the density of the catalyst fine particles in each region and taking the arithmetic average, the catalyst fine particle density was 8.8 × 10 ¹¹ particles / cm ² . .

Preparation of the base material described so far in this example and production of the aligned CNT aggregate by the CVD method were performed on 30 substrates, and the stability was evaluated. As a result of the growth failure when the production amount was 0.4 mg / cm ² or less, 3 growth failures (10%) occurred among 30 substrates.

[Comparative Example 1]
As a substrate, a Fe—Cr alloy SUS430 (manufactured by JFE Steel Co., Ltd., Cr 18%) having a size of 40 mm × 100 mm and a thickness of 0.3 mm was used. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra≈0.063 μm.

  Using a sputtering apparatus, aluminum oxide 10 nm was formed on the substrate to form a catalyst support layer. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra≈0.055 μm. SEM observation of the surface of the obtained catalyst support layer was performed. The results are shown in FIG. FIG. 8 is a diagram showing the results of SEM observation of the surface of the catalyst support layer of this comparative example. No pores were observed on the surface, and the surface was flat.

  Then, 1.0 nm of iron was laminated | stacked on the catalyst support layer using the sputtering device, and the catalyst layer was formed.

Using the obtained base material, CVD was performed under the same conditions as in Example 1 to obtain an aggregate of oriented single-walled CNTs. The properties of the aligned single-walled CNT aggregate were as follows: production amount 1.8 mg / cm ² , G / D ratio 6.0, density: 0.030 g / cm ³ , BET-specific surface area: 1100 m ² / g, CNT The outer diameter was 0.8-5.0 nm, the CNT average outer diameter was 2.8 nm, and the carbon purity was 99.9%. The average height of the aligned CNT aggregate calculated from the production amount and density is 600 μm.

Preparation of the base material explained so far in this comparative example and production of the aligned CNT aggregate by the CVD method were performed on 30 substrates, and the stability was evaluated. As a result of the growth failure when the production amount was 0.4 mg / cm ² or less, 8 growth failures (27%) out of 30 substrates were generated.

[Comparative Example 2]
1.6 g of tetraethyl orthosilicate was dissolved in 100 ml of ethanol. Further, 0.98 g of ethyl acetoacetate as a stabilizer was added and dissolved to prepare a catalyst-supporting layer coating agent.

  As a substrate, a Fe—Cr alloy SUS430 (manufactured by JFE Steel Co., Ltd., Cr 18%) having a size of 40 mm × 100 mm and a thickness of 0.3 mm was used. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra≈0.063 μm.

  The above-mentioned catalyst supporting layer coating agent was applied on the substrate by dip coating in an environment of room temperature of 25 ° C. and relative humidity of 50%. As application conditions, the substrate was dipped, held for 20 seconds, and the substrate was lifted at a pulling rate of 10 mm / second. Thereafter, it was air-dried for 5 minutes.

  Next, it heated for 120 minutes in 900 degreeC air environment. After heating, it was cooled to room temperature. As a result, a catalyst support layer having a thickness of 30 nm was formed on the substrate. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra≈0.040 μm.

  Next, in the same manner as in Example 1, formation of a catalyst layer and synthesis of CNTs by a CVD method were attempted. However, no CNT was produced on the substrate.

[Comparative Example 3]
Alumina sol (aluminum sol-10D, Kawaken Fine Chemical Co., Ltd., 10% boehmite alumina DMF solution) was diluted with DMF (dimethylformamide) to prepare 3% alumina sol (boehmite alumina DMF solution).

  Iron (III) nitrate nonahydrate 1.52 g (3.75 mmol) was dissolved in about 40 ml of ethanol and placed in a separatory funnel. About 200 ml of ethanol is put in a 300 ml Erlenmeyer flask and heated and boiled with an electric heater, and the above-mentioned iron nitrate solution is dropped at a rate of about 10 ml / min while continuing to boil. After completion of dropping, the Erlenmeyer flask was immersed in cold water to cool to room temperature, and ethanol was added to make the total volume 250 ml. As described above, a dark reddish brown and transparent iron oxide sol having an iron concentration of 15 mmol / l was prepared.

  A Fe-Ni-Cr alloy YEF426 (manufactured by Hitachi Metals, Ni 42%, Cr 6%) having a size of 40 mm square and a thickness of 0.3 mm was used as the substrate. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra≈0.24 μm.

  The above-mentioned alumina sol was applied onto the substrate by spin coating in an environment of room temperature of 25 ° C. and relative humidity of 50%. As application conditions, 0.1 ml of the solution was dropped on the substrate, and then rotated at 500 rpm for 10 seconds and then at 2000 rpm for 20 seconds. Thereafter, it was air-dried for 5 minutes.

  Next, it heated for 30 minutes in 700 degreeC air environment. After heating, it was cooled to room temperature. As a result, a catalyst support layer made of aluminum oxide having a thickness of 110 nm was formed on the substrate. When the surface roughness was measured using a laser microscope, the arithmetic average roughness Ra≈0.20 μm.

The catalyst-carrying layer was thin and could not obtain a sufficient weight for measuring the BET specific surface area. Therefore, the following measurements were performed on the porosity of the catalyst support layer. 1.0 ml of the above-mentioned alumina sol was dropped on a glass plate, and then air-dried for 5 minutes. Next, after heating for 30 minutes in an air environment at 700 ° C., the mixture was cooled to room temperature. The BET specific surface area of the solid obtained on the glass plate was 150 m ² / g. The solid obtained here has the same type of catalyst-supporting layer coating agent and heating conditions as when the catalyst-supporting layer obtained in this comparative example was formed. Therefore, it is estimated that the solid has a BET specific surface area comparable to that of the catalyst support layer obtained in this comparative example.

  The iron oxide sol described above was applied by spin coating on the catalyst support layer of the substrate in an environment of room temperature of 25 ° C. and relative humidity of 50%. As application conditions, 0.1 ml of the solution was dropped on the substrate, and then rotated at 500 rpm for 10 seconds and then at 2000 rpm for 20 seconds. Thereafter, it was air-dried for 5 minutes.

  Next, it heated in the air for 30 minutes in 700 degreeC air environment. After heating, it was cooled to room temperature. As a result, a catalyst layer made of iron oxide was formed on the substrate.

Using this substrate, CVD was performed under the same conditions as in Example 1. The characteristics of the obtained aligned CNT aggregate depend on the details of production conditions, but as typical values, the production amount is 0.5 mg / cm ² , the G / D ratio is 2.0, the density is 0.030 g / cm ³ , BET-specific surface area: 550 m ² / g, production was low, and BET-specific surface area was also significantly low. The average height of the aligned CNT aggregate calculated from the production amount and density is 170 μm.

  Comparative Example 3 is similar to the method described in Patent Document 1 except that the catalyst layer is formed by a sol-gel method. And in Examples 1-4, since the aligned CNT aggregate having a much higher height than that of Comparative Example 3 was obtained, the present invention is more efficient than the Patent Document 1 in that the aligned CNT aggregate is obtained. It was confirmed that it could be manufactured. Furthermore, since the thickness (CNT height) of the CNT film obtained in the example of Patent Document 1 is 5 to 15 μm, according to the present invention, the aligned CNT aggregate can be produced more efficiently than Patent Document 1. It was confirmed that it was obtained.

  The aligned CNT aggregate obtained by using the substrate for manufacturing an aligned CNT aggregate according to the present invention can be suitably used in fields such as electronic device materials, optical element materials, and conductive materials.

1-1 Catalyst support layer 1-2 Hole 1-3 CNT
1-4 Catalyst particles

Claims (12)

A substrate, a catalyst support layer and a catalyst layer;
The catalyst supporting layer, Ri greens by applying a catalyst supporting layer coating comprising a stabilizer for preventing the condensation polymerization reaction of the organoaluminum compound and the organoaluminum compound on the substrate, aluminum oxide plate structure It has a hole on its surface,
The carbon nanotube orientation characterized in that the catalyst layer is a layer of catalyst particles that selectively exposes at least a portion of the pores and is on the surface and in a non-porous location. Base material for assembly production.   The base material for producing an aligned carbon nanotube aggregate according to claim 1, wherein the catalyst support layer is porous.   The base material for producing an aligned carbon nanotube aggregate according to claim 1 or 2, wherein the catalyst support layer has mesopores having a pore diameter of 1 to 50 nm.   4. The substrate for producing an aligned carbon nanotube aggregate according to claim 1, wherein the surface of the catalyst support layer has an arithmetic average roughness Ra of 0.05 μm or less.   5. The substrate for producing an aligned carbon nanotube aggregate according to claim 1, wherein the catalyst supporting layer has a thickness of 10 nm or more and 100 nm or less. In the catalyst layer, the density of the particles of the catalyst, 1.0 × ^{10 11} / cm ² or more, any of the preceding claims, characterized in that 2.0 × is ^{10 12} / cm ² or less 2. A substrate for producing an aligned carbon nanotube aggregate according to claim 1. The surrounding environment of the substrate for manufacturing an aligned carbon nanotube assembly is set to an environment containing a raw material gas for carbon nanotubes, and at least one of the base material for manufacturing an aligned carbon nanotube assembly and the source gas is heated, Including a growth step of growing an aligned aggregate of carbon nanotubes by growth,
The base material for producing an aligned aggregate of carbon nanotubes includes a substrate, a catalyst support layer, and a catalyst layer,
The catalyst supporting layer is Ri greens by coating a catalyst supporting layer coating comprising a stabilizer for preventing the condensation polymerization reaction of the organoaluminum compound and the organoaluminum compound on the substrate, aluminum oxide plate structure And the surface has a hole,
The method for producing an aligned aggregate of carbon nanotubes, wherein the catalyst layer is a layer of catalyst particles on the surface and in a non-porous location.   The method of manufacturing an aligned carbon nanotube assembly according to claim 7, wherein the ambient environment further includes a catalyst activator. It is a manufacturing method of the substrate for carbon nanotube alignment aggregate manufacture according to any one of claims 1 to 6,
A catalyst-carrying layer forming step of applying a catalyst-carrying layer coating agent containing an organoaluminum compound and a stabilizer for suppressing the condensation polymerization reaction of the organoaluminum compound on the substrate, and providing the catalyst-carrying layer on the substrate;
A catalyst layer forming step of applying a catalyst layer coating agent containing at least one selected from the group consisting of an organometallic compound and a metal salt on the catalyst support layer, and providing a catalyst layer on the catalyst support layer;
A method for producing a base material for producing an aligned carbon nanotube aggregate, comprising:   In the said catalyst carrying layer formation process, after apply | coating the said catalyst carrying layer coating agent, it heats at 200 degreeC or more and 400 degrees C or less, The carbon nanotube aligned assembly manufacturing base material of Claim 9 characterized by the above-mentioned. Production method.   It heats for 5 minutes or more and 3 hours or less, The manufacturing method of the base material for carbon nanotube aligned assembly manufacture of Claim 10 characterized by the above-mentioned. After the catalyst layer forming step, the method further includes a formation step of setting at least one of the substrate and the reducing gas as an environment including a reducing gas as an environment surrounding the substrate, and reducing and granulating the catalyst layer. The method for producing a substrate for producing an aligned carbon nanotube aggregate according to any one of claims 9 to 11, wherein: