WO2016152105A1 - Method for producing carbon nanostructure - Google Patents

Method for producing carbon nanostructure Download PDF

Info

Publication number
WO2016152105A1
WO2016152105A1 PCT/JP2016/001517 JP2016001517W WO2016152105A1 WO 2016152105 A1 WO2016152105 A1 WO 2016152105A1 JP 2016001517 W JP2016001517 W JP 2016001517W WO 2016152105 A1 WO2016152105 A1 WO 2016152105A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
catalyst
hydrocarbon
carbon
carbon nanostructure
Prior art date
Application number
PCT/JP2016/001517
Other languages
French (fr)
Japanese (ja)
Inventor
明慶 渋谷
Original Assignee
日本ゼオン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Priority to JP2017507481A priority Critical patent/JP6673337B2/en
Publication of WO2016152105A1 publication Critical patent/WO2016152105A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30

Definitions

  • the present invention relates to a method for producing a carbon nanostructure.
  • Carbon nanostructures are attracting attention as the core material of nanotechnology.
  • the “carbon nanostructure” is a nano-sized substance composed of carbon atoms.
  • a coiled carbon nanocoil a tube-shaped carbon nanotube (hereinafter also referred to as “CNT”)
  • CNT tube-shaped carbon nanotube
  • These carbon nanostructures are common in terms of depositing nanostructures containing carbon consisting of sp2 hybrid orbitals on the metal (catalyst) surface using chemical vapor deposition, and there are many production methods. Analogy can be applied.
  • a method of growing a carbon nanostructure by a chemical vapor deposition method (hereinafter also referred to as “CVD method”) by supplying a raw material gas to a catalyst is known.
  • CVD method a chemical vapor deposition method
  • a raw material gas containing a carbon compound is supplied to the metal fine particles of the catalyst in a high temperature atmosphere of about 500 ° C. to 1000 ° C.
  • various carbon nanostructures can be produced by variously changing the type and arrangement of the catalyst, the type of raw material gas, the reaction conditions, and the like.
  • Patent Document 1 describes a method for producing CNTs by a CVD method using methane (CH 4 ) or ethylene (C 2 H 4 ) as a source gas and containing alkyne in the gas in contact with the catalyst.
  • Patent Document 2 describes a method of producing CNTs by a CVD method by using a hydrocarbon gas such as methane, ethylene, acetylene (C 2 H 2 ), or the like as a source gas and spraying the source gas on a catalyst. .
  • the CNT manufacturing technology by the CVD method can manufacture both single-walled carbon nanotubes (SWCNT) and multi-walled carbon nanotubes (MWCNT), and is oriented perpendicular to the substrate surface by using a substrate carrying a catalyst. It has the advantage that a large number of CNTs can be produced. In addition, since the development of a super-growth method in which a catalyst activator such as water is brought into contact with a catalyst together with a raw material gas, it has attracted attention as being suitable for mass production of CNTs.
  • an object of the present invention is to provide a method for producing a carbon nanostructure capable of producing a high-quality carbon nanostructure with high efficiency.
  • the present inventor obtained the following knowledge as a result of intensive studies. That is, the present inventor paid attention to the composition of the gas that actually contacts the catalyst (hereinafter also simply referred to as “contact gas”), not the raw material gas.
  • contact gas the composition of the gas that actually contacts the catalyst
  • CNT precursors other than acetylene were newly identified from a large number of hydrocarbon gases produced by the thermal decomposition of ethylene, which is one of the raw material gases conventionally used.
  • the efficiency of CNT synthesis can be greatly improved by bringing a gas obtained by mixing these CNT precursors at a predetermined volume concentration into contact with the catalyst.
  • a mixed gas containing hydrocarbon A having at least one acetylene skeleton and hydrocarbon B having at least one 1,3-butadiene skeleton in a predetermined volume concentration is effective. It was.
  • composition of the raw material gas capable of setting the gas components of the CNT precursor in the contact gas to a predetermined volume concentration or higher was also specified. From the above knowledge, a method capable of producing a high-quality carbon nanostructure with high efficiency has been established, and the present invention has been completed.
  • the present invention does not merely specify the composition of the gas that comes into contact with the catalyst in conventional CNT production.
  • the source gas used in the present invention is different from Patent Documents 1 and 2, and the contact gas is also different from Patent Document 1.
  • Patent Document 2 does not focus on contact gas at all.
  • the gist configuration of the present invention completed based on the above findings is as follows.
  • the present invention A method for producing a carbon nanostructure in which a raw material gas is supplied to a catalyst and a carbon nanostructure is grown by chemical vapor deposition, Gas X derived from the raw material gas and contacting the catalyst contains hydrocarbon A having at least one acetylene skeleton and hydrocarbon B having at least one 1,3-butadiene skeleton, The total volume concentration [A] of the hydrocarbon A exceeds 0.1%, and the total volume concentration [B] of the hydrocarbon B is 0.28% or more.
  • the gas X preferably satisfies 0.1 ⁇ [A] / [B] ⁇ 8.
  • the gas X further includes a catalyst activation material and / or a hydrogen molecule.
  • the gas X further includes hydrocarbon C having at least one cyclopentadiene skeleton.
  • the present invention also provides: A method for producing a carbon nanostructure in which a raw material gas is supplied to a catalyst and a carbon nanostructure is grown by chemical vapor deposition,
  • the source gas contains hydrocarbon A ′ having at least one acetylene skeleton and hydrocarbon B ′ having at least one 1,3-butadiene skeleton.
  • the raw material gas is 0.1 ⁇ [A ′. ] / [B ′] ⁇ 6 is preferably satisfied.
  • the source gas further includes a catalyst activation material and / or a hydrogen molecule.
  • the source gas further includes a hydrocarbon C ′ having at least one carbon ring having 5 carbon atoms.
  • the catalyst is supported on the surface of a base material, and the raw material gas is supplied to the catalyst by a gas shower.
  • the carbon nanostructure is preferably a carbon nanotube.
  • a high-quality carbon nanostructure can be produced with high efficiency.
  • a raw material gas is supplied to a substrate having a catalyst layer on the surface (hereinafter referred to as “catalyst substrate”), and CNTs are grown on the catalyst layer by chemical vapor deposition.
  • a large number of CNTs are oriented in a direction substantially perpendicular to the substrate to form an aggregate. In the present invention, this is referred to as “CNT aligned aggregate”.
  • the base material used for the catalyst base material is, for example, a flat plate-like member, and a material that can maintain the shape even at a high temperature of 500 ° C. or higher is preferable.
  • 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, or nonmetals such as silicon, quartz, glass, mica, graphite, and diamond, and ceramics.
  • the metal material is preferable because it is low in cost and easy to process as compared with silicon and ceramic, and in particular, Fe—Cr (iron-chromium) alloy, Fe—Ni (iron-nickel) alloy, Fe—Cr—Ni ( An iron-chromium-nickel alloy or the like is preferred.
  • Examples of the form of the substrate include a flat plate shape, a thin film shape, a block shape, a wire shape, a mesh shape, or a particle / fine particle / powder shape.
  • a shape that can take a large surface area for a large volume produces a large amount of CNT.
  • limiting in particular in the thickness of a flat base material For example, the thing from about several micrometers thin film to about several cm can be used.
  • the thickness of the flat substrate is preferably 0.05 mm or more and 3 mm or less.
  • a catalyst layer is formed on the base material (when the carburization prevention layer is provided on the base material, on the carburization prevention layer).
  • the catalyst may be any as long as it can produce CNTs, and examples thereof include iron, nickel, cobalt, molybdenum, and chlorides and alloys thereof. A plurality of these may be combined or layered, and these may be further combined or layered with aluminum, alumina, titania, titanium nitride, or silicon oxide.
  • iron-molybdenum thin film, alumina-iron thin film, alumina-cobalt thin film, alumina-iron-molybdenum thin film, aluminum-iron thin film, 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.
  • the film thickness is preferably 0.1 nm or more and 100 nm or less, and 0.5 nm or more and 5 nm or less. More preferably, it is 0.8 nm or more and 2 nm or less.
  • a wet process or a dry process (such as sputtering deposition) may be applied. It is preferable to apply a wet process from the viewpoints of the convenience of the film formation apparatus (no vacuum process is required), the throughput speed, the low raw material costs, and the like.
  • the wet process for forming the catalyst layer includes a step of applying a coating agent obtained by dissolving a metal organic compound and / or metal salt containing an element serving as a catalyst in an organic solvent, and then a step of heating. You may add the stabilizer for suppressing the excessive condensation polymerization reaction of a metal organic compound and a metal salt to a coating agent.
  • any method such as spray coating, brush coating, spin coating, and dip coating may be used, but dip coating is preferred from the viewpoint of productivity and film thickness control.
  • the heating temperature is preferably in the range of about 50 ° C. or more and 400 ° C. or less, and the heating time is preferably in the range of 5 minutes or more and 3 hours or less.
  • the iron thin film is formed after the alumina film is formed.
  • Examples of the metal organic compound for forming the alumina thin film include aluminum trimethoxide, aluminum triethoxide, aluminum tri-n-propoxide, aluminum tri-i-propoxide, aluminum tri-n-butoxide, aluminum tri-sec. -Aluminum alkoxides such as butoxide and aluminum tri-tert-butoxide.
  • Other examples of the metal organic compound containing aluminum include complexes such as tris (acetylacetonato) aluminum (III).
  • Examples of the metal salt for forming the alumina thin film include aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum bromide, aluminum iodide, aluminum lactate, basic aluminum chloride, basic aluminum nitrate and the like. Among these, it is preferable to use aluminum alkoxide. These can be used alone or as a mixture of two or more.
  • Examples of the metal organic compound for forming the iron thin film include iron pentacarbonyl, ferrocene, acetylacetone iron (II), acetylacetone iron (III), trifluoroacetylacetone iron (II), trifluoroacetylacetone iron (III) and the like.
  • Examples of metal salts for forming an iron thin film include iron sulfate, iron nitrate, iron phosphate, iron chloride, iron bromide and other inorganic acid iron, iron acetate, iron oxalate, iron citrate, lactic acid
  • Examples thereof include organic acid irons such as iron. Among these, it is preferable to use organic acid iron. These can be used alone or as a mixture of two or more.
  • the stabilizer is preferably at least one selected from the group consisting of ⁇ -diketones and alkanolamines. These compounds may be used alone or in combination of two or more.
  • ⁇ -diketones include acetylacetone, methyl acetoacetate, ethyl acetoacetate, benzoylacetone, dibenzoylmethane, benzoyltrifluoroacetone, furoylacetone, and trifluoroacetylacetone. preferable.
  • alkanolamines include monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylaminoethanol, diisopropanolamine, and triisopropanolamine.
  • a secondary alkanolamine is preferred.
  • organic solvent various organic solvents such as alcohols, glycols, ketones, ethers, esters, hydrocarbons and the like can be used, but alcohols or glycols are used because of the good solubility of metal organic compounds and metal salts. Is preferred. These organic solvents may be used alone or in combination of two or more.
  • alcohol methanol, ethanol, isopropyl alcohol, and the like are preferable in terms of handling properties and storage stability.
  • the content of the metal organic compound and / or metal salt in the coating agent is usually 0.05% by mass or more and 0.5% by mass or less, preferably 0.1% by mass or more and 0.5% by mass. It is as follows.
  • the formation step is a step of heating at least one of the catalyst and the reducing gas while setting the environment surrounding the catalyst as the reducing gas environment.
  • the formation step at least one of the effects of reducing the catalyst, promoting the atomization of the catalyst in a state suitable for the growth of CNT, and improving the activity of the catalyst appears.
  • the catalyst is an alumina-iron thin film
  • the iron catalyst is reduced into fine particles, and a large number of nanometer-sized iron fine particles are formed on the alumina layer.
  • the catalyst is in a state suitable for the production of the aligned CNT aggregate. Even if this step is omitted, CNTs can be produced.
  • the production amount and quality of the aligned CNT aggregate can be dramatically improved.
  • the reducible gas a gas capable of producing CNTs may be used.
  • a gas capable of producing CNTs may be used.
  • hydrogen gas, ammonia, water vapor, and a mixed gas thereof can be applied.
  • a mixed gas obtained by mixing hydrogen gas with an inert gas such as helium gas, argon gas, and nitrogen gas may be used.
  • the reducing gas may be used in the growth process as appropriate in addition to the formation process.
  • the growth step is a step of growing an aligned CNT aggregate on the catalyst by setting the surrounding environment of the catalyst as a raw material gas environment and heating at least one of the catalyst and the raw material gas. From the viewpoint of growing high-quality CNTs, it is preferable to heat at least the catalyst.
  • the heating temperature is preferably 400 ° C. or higher and 1100 ° C. or lower.
  • the growth step is performed by introducing a raw material gas containing an inert gas and, optionally, a reducing gas and / or a catalyst activation material into a CNT growth furnace containing the catalyst substrate.
  • the present invention has one major feature in the gas X that contacts the catalyst during the growth process.
  • the gas X is composed of various hydrocarbon gases obtained by decomposing the raw material gas, a raw material gas that has reached the catalyst without being decomposed, an inert gas, and a reducing gas and / or a catalyst activation material optionally contained. .
  • the gas X includes hydrocarbon A having at least one acetylene skeleton and hydrocarbon B having at least one 1,3-butadiene skeleton, and the total volume concentration [A] of the hydrocarbon A is 0. It is important that the total volume concentration [B] of hydrocarbon B exceeds 0.28%.
  • acetylenes a hydrocarbon having at least one acetylene skeleton
  • 1,3-butadiene skeleton referred to as “1,3-butadienes”. is there.
  • hydrocarbon A having at least one acetylene skeleton examples include acetylene, methylacetylene (propyne), vinylacetylene, 1-butyne (ethylacetylene), 2-butyne, diacetylene, isopropylacetylene, isopropenylacetylene, 1- Examples thereof include at least one selected from the group consisting of pentyne, 2-pentyne, isopentine, cyclopropenylacetylene, methylvinylacetylene, propenylacetylene, phenylacetylene, hexynes, hexadiynes, and radicals thereof.
  • acetylene, methylacetylene, vinylacetylene, 2-butyne, and phenylacetylene are preferred from the viewpoint of structural stability at the CNT growth temperature.
  • hydrocarbon B having at least one 1,3-butadiene skeleton examples include at least one selected from the group consisting of 1,3-butadiene, isoprene, c-piperylene, and t-piperylene, and radicals thereof. Is mentioned. However, 1,3-butadiene is preferred from the viewpoint of CNT production efficiency.
  • the total volume concentration [A] of the hydrocarbon A in the gas X in contact with the catalyst is more than 0.1%.
  • [A] is more preferably 0.3% or more, and further preferably 0.5% or more.
  • the upper limit concentration of [A] tends to be proportional to the spatial density of the catalyst installed in the furnace, and can be increased to 88%.
  • a flat plate is used as the catalyst base, it is usually preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less. If the concentration of hydrocarbon A is excessive with respect to the catalyst density, the amount of carbon impurities such as amorphous carbon produced increases, and these impurities cannot be ignored depending on the application.
  • the total volume concentration [B] of hydrocarbon B in gas X is 0.28% or more.
  • [B] is more preferably 0.5% or more, and even more preferably 0.6% or more.
  • the upper limit concentration of [B] tends to be proportional to the spatial density of the catalyst installed in the furnace, and can be increased to 90%.
  • a flat plate is used as the catalyst base, it is usually preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less. If the concentration of hydrocarbon B is excessive with respect to the catalyst density, the amount of carbon impurities such as amorphous carbon produced increases, and these impurities cannot be ignored depending on the application.
  • [A] / [B] is preferably 0.1 or more and 8 or less from the viewpoint of obtaining the effect of the present invention more sufficiently. More preferably, they are 0.2 or more and 6 or less, More preferably, they are 0.5 or more and 2 or less.
  • the gas X preferably further contains a hydrocarbon C having at least one cyclopentadiene skeleton.
  • the hydrocarbon C is, for example, selected from the group consisting of cyclopentadiene, indene, methylcyclopentadiene, dimethylcyclopentadiene, trimethylcyclopentadiene, tetramethylcyclopentadiene, pentamethylcyclopentadiene, and ethylcyclopentadiene, and radicals thereof. And at least one of them.
  • cyclopentadiene and methylcyclopentadiene are preferred from the viewpoint of structural stability at the CNT growth temperature.
  • hydrocarbon C By including the hydrocarbon C in the gas X, it is possible to reduce the required hydrocarbon A while maintaining the yield and quality of CNT. Since acetylenes have high chemical reactivity, there is a problem in handling and safety compared to other gases, and there is a tendency that operation costs increase. Therefore, it is preferable to reduce the amount of hydrocarbon A used as much as possible.
  • the total volume concentration [C] of hydrocarbon C in gas X is preferably 0.06% or more, more preferably 0.2% or more, and still more preferably, from the viewpoint of sufficiently obtaining the above effect. It is 0.3% or more. Further, the total volume concentration [C] of the hydrocarbons C in the gas X tends to be proportional to the spatial density of the catalyst installed in the furnace, and can be increased to 99%. From the viewpoint of suppressing the generation of carbon impurities such as amorphous carbon, when a flat plate is used as the catalyst substrate, it is usually preferably 10% or less, more preferably 5% or less, and further preferably 2% or less. In the present specification, a hydrocarbon having at least one cyclopentadiene skeleton may be referred to as “cyclopentadiene”.
  • the identification of the contact gas and the measurement of the volume concentration are performed by sucking and sampling a predetermined amount of gas in the vicinity of the substrate installation position and performing gas analysis by gas chromatography (GC).
  • GC gas chromatography
  • the gas is rapidly cooled to a temperature at which pyrolysis does not proceed (about 200 ° C.) in a short time, and then immediately introduced into the GC. This prevents chemical changes in the sample gas and makes it possible to correctly measure the composition of the gas in contact with the catalyst.
  • the source gas preferably contains a hydrocarbon A ′ having at least one acetylene skeleton and a hydrocarbon B ′ having at least one 1,3-butadiene skeleton. .
  • the hydrocarbon A ′ is preferably at least one selected from the group consisting of acetylene, methylacetylene, vinylacetylene, 1-butyne, 2-butyne, isopropylacetylene and isopropenylacetylene.
  • the total volume concentration [A ′] of the hydrocarbon A ′ in the raw material gas is preferably 0.1% or more, more preferably 0.2% or more, and further preferably 0.3% or more.
  • [A '] can be increased to 86%, and is usually preferably 10% or less, more preferably 5% or less, and still more preferably 2% or less. If the concentration of the hydrocarbon A ′ is too low, it is difficult to obtain the effect of the present invention. If the concentration is too high, carbon impurities such as amorphous carbon are generated, and depending on the application, these impurities tend not to be negligible.
  • the hydrocarbon B ′ is preferably at least one selected from the group consisting of 1,3-butadiene, isoprene, c-piperylene, and t-piperylene.
  • the total volume concentration [B ′] of hydrocarbon B ′ is preferably 0.3% or more, more preferably 0.4% or more, and further preferably 0.5% or more.
  • [B ′] can be increased to 90%, and is usually preferably 10% or less, more preferably 5% or less, and further preferably 2% or less. If the concentration of the hydrocarbon B ′ is too low, it is difficult to obtain the effect of the present invention. If the concentration is too high, carbon impurities such as amorphous carbon are generated, and depending on the use, these impurities cannot be ignored.
  • [A ′] / [B ′] is preferably 0.1 or more and 6 or less. More preferably, they are 0.2 or more and 3 or less, More preferably, they are 0.3 or more and 2 or less. By setting it within this range, the gas X can be more reliably set within the range of the present invention.
  • the source gas preferably contains hydrocarbon C ′ having at least one carbon ring having 5 carbon atoms.
  • the hydrocarbon C ′ is preferably at least one selected from the group consisting of cyclopentadiene, dicyclopentadiene, cyclopentene, norbornene, norbornadiene, and cyclopentane.
  • the total volume concentration [C ′] of hydrocarbon C ′ in the raw material gas is preferably 0.1% or more, more preferably 0.2% or more, and still more preferably. It is 0.3% or more. If the concentration of the hydrocarbon C ′ is too low, it is difficult to obtain the effects of the present invention. If the concentration is too high, carbon impurities such as amorphous carbon are generated, and these impurities tend not to be negligible depending on the application.
  • the total volume concentration [C ′] of hydrocarbons C ′ in the raw material gas tends to be proportional to the spatial density of the catalyst installed in the furnace, and can be increased to 99%. From the viewpoint of suppressing the generation of carbon impurities such as amorphous carbon, when a flat plate is used as the catalyst substrate, it is usually preferably 10% or less, more preferably 5% or less, and further preferably 2% or less.
  • the source gas is usually diluted with an inert gas.
  • the inert gas may be any gas that is inert at the temperature at which the CNT grows and does not react with the growing CNT, and preferably does not reduce the activity of the catalyst.
  • noble gases such as helium, argon, neon, and krypton, nitrogen, hydrogen, and mixed gas thereof can be exemplified.
  • a catalyst activator may be added.
  • the catalyst activator used here is generally a substance containing oxygen, and is preferably a substance that does not significantly damage the CNT at the growth temperature.
  • low carbon number oxygen-containing compounds such as water, oxygen, ozone, acidic gas, nitrogen oxide, carbon monoxide, and carbon dioxide; alcohols such as ethanol and methanol; ethers such as tetrahydrofuran; ketones such as acetone Aldehydes; esters; as well as mixtures thereof are useful.
  • water, oxygen, carbon monoxide, carbon dioxide, and ethers are preferable, and water, carbon monoxide, carbon dioxide, and a mixture thereof are particularly preferable.
  • the volume concentration of the catalyst activator is not particularly limited, but may be a very small amount.
  • the content is usually 0.001% or more and 1% or less, preferably in the raw material gas introduced into the furnace. 0.005% or more and 0.1% or less.
  • the gas X is usually 0.001% or more and 1% or less, preferably 0.005% or more and 0.1% or less.
  • the catalyst activation material is carbon dioxide
  • the content of the raw material gas introduced into the furnace is usually 0.5% or more and 20% or less, preferably 2% or more and 8% or less.
  • the gas X is usually 0.5% or more and 20% or less, preferably 2% or more and 8% or less.
  • the gas X preferably further contains a hydrogen gas composed of hydrogen molecules as a catalyst activator and / or a reducing gas from the viewpoint of obtaining the effects of the present invention more sufficiently.
  • the partial pressure (volume fraction ⁇ total pressure) of the components involved in the reaction affects the reaction rate in the CVD method.
  • the total pressure does not directly affect, it can be changed in a wide range. Therefore, it is accurate to use the partial pressure as a unit for defining the gas component concentration in the CVD condition.
  • the gas component concentration of the source gas and the contact gas is set to the total pressure in the growth reactor of 1 atm. Describe the volume fraction under the assumption. Therefore, when the present invention is applied when the total pressure in the growth furnace is other than 1 atm, the partial pressure equal to the partial pressure under the above-mentioned assumption is used as the gas component concentration of the source gas and the contact gas in the environment. A corrected volume fraction should be used as shown. Such modifications will be apparent to those skilled in the art when the total pressure in the growth reactor is other than 1 atm. Therefore, such cases are also included in the scope of the present invention.
  • the pressure in the reactor and the treatment time in the growth step may be appropriately set in consideration of other conditions.
  • the pressure is 10 2 Pa or more and 10 7 Pa or less
  • the treatment time is 0.1 minutes or more and It can be about 120 minutes or less.
  • the cooling step is a step of cooling the aligned CNT aggregate, the catalyst, and the base material under a cooling gas after the growth step. Since the aligned CNT aggregate, the catalyst, and the substrate after the growth step are in a high temperature state, they may be oxidized when placed in an oxygen-existing environment. In order to prevent this, the aligned CNT aggregate, the catalyst, and the substrate are cooled to, for example, 400 ° C. or lower, more preferably 200 ° C. or lower, in a cooling gas environment. As the cooling gas, an inert gas is preferable, and nitrogen is particularly preferable from the viewpoints of safety and cost.
  • the manufacturing apparatus used for carrying out the present invention is not particularly limited as long as it has a growth furnace (reaction chamber) for receiving a catalyst base material and can grow CNTs by a CVD method.
  • Equipment such as a reactor can be used.
  • a gas flow can be ejected so as to be substantially orthogonal to the catalyst base.
  • An example of an apparatus provided with a shower head will also be described.
  • the apparatus 100 includes a reaction furnace 102 made of quartz, a heater 104 made of, for example, a resistance heating coil provided so as to surround the reaction furnace 102, and a reaction furnace 102 for supplying a reducing gas and a source gas. It includes a gas supply port 106 connected to one end, an exhaust port 108 connected to the other end of the reaction furnace 102, and a holder 110 made of quartz for fixing the substrate.
  • a control device including a flow rate control valve, a pressure control valve, and the like is provided at an appropriate place in order to control the flow rates of the reducing gas and the raw material gas.
  • a CNT manufacturing apparatus 200 applied to the present invention is schematically shown in FIG.
  • the apparatus 200 has the same configuration as the apparatus shown in FIG. 1 except that a shower head 112 that injects a reducing gas, a raw material gas, a catalyst activation material, and the like is used.
  • the shower head 112 is disposed so that the spray axis of each spray hole is in a direction substantially perpendicular to the catalyst coating surface of the base material. That is, the direction of the gas flow ejected from the ejection holes provided in the shower head is substantially orthogonal to the base material.
  • the reducing gas When the reducing gas is injected using the shower head 112, the reducing gas can be uniformly sprayed on the substrate, and the catalyst can be reduced efficiently. As a result, the uniformity of the aligned CNT aggregates grown on the substrate can be improved, and the consumption of reducing gas can also be reduced.
  • the raw material gas When the raw material gas is injected using such a shower head, the raw material gas can be uniformly sprayed on the substrate, and the raw material 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.
  • a catalyst activation material When a catalyst activation material is injected using such a showerhead, the catalyst activation material can be uniformly sprayed on the substrate, and the activity of the catalyst is increased and the lifetime is extended. It becomes possible to make it.
  • a CNT production apparatus 300 applied to the present invention is schematically shown in FIG.
  • the manufacturing apparatus 300 includes an inlet purge unit 1, a formation unit 2, a growth unit 3, a cooling unit 4, an outlet purge unit 5, a transport unit 6, connection units 7, 8, 9, and gas mixture prevention. Means 11, 12, and 13 are included.
  • the inlet purge unit 1 is a set of devices for preventing outside air from entering the furnace from the inlet of the catalyst base 10. It has a function of replacing the surrounding environment of the catalyst substrate 10 conveyed into the manufacturing apparatus 300 with an inert purge gas such as nitrogen. Specifically, a chamber for holding the purge gas, an injection unit for injecting the purge gas, and the like are included.
  • the formation unit 2 is a set of devices for realizing the formation process. Specifically, it includes a formation furnace 2A for holding the reducing gas, a reducing gas injection unit 2B for injecting the reducing gas, and a heater 2C for heating at least one of the catalyst and the reducing gas.
  • the growth unit 3 is a set of apparatuses for realizing a growth process. Specifically, a growth furnace 3A, a raw material gas injection unit 3B for injecting a raw material gas onto the catalyst base 10, and a heater 3C for heating at least one of the catalyst and the raw material gas are included. An exhaust port 3 ⁇ / b> D is provided in the upper part of the growth unit 3.
  • the cooling unit 4 is a set of devices that realizes a cooling process for cooling the catalyst base 10 on which the aligned CNT aggregate has grown. Specifically, the cooling furnace 4A for holding the cooling gas, in the case of the water-cooled type, the water-cooled cooling pipe 4C disposed so as to surround the space in the cooling furnace, and in the case of the air-cooled type, the cooling gas is injected into the cooling furnace. It has the cooling gas injection part 4B.
  • the outlet purge unit 5 is a set of devices for preventing outside air from being mixed into the furnace from the outlet of the catalyst base 10. It has a function to make the surrounding environment of the catalyst substrate 10 an inert purge gas environment such as nitrogen. Specifically, a chamber for holding the purge gas, an injection unit for injecting the purge gas, and the like are included.
  • the transport unit 6 is a set of apparatuses for transporting the catalyst base 10 into the furnace of the manufacturing apparatus. Specifically, a mesh belt 6A in a belt conveyor system, a belt driving unit 6B using an electric motor with a reduction gear, and the like are included.
  • connection portions 7, 8, and 9 are a set of devices that spatially connect the furnace space of each unit. Specifically, a furnace or a chamber that can block the ambient environment of the catalyst base 10 and the outside air and allow the catalyst base 10 to pass from unit to unit can be used.
  • the gas mixing prevention means 11, 12, 13 are a set of devices for preventing gas from being mixed with each other between adjacent furnaces (formation furnace 2 ⁇ / b> A, growth furnace 3 ⁇ / b> A, cooling furnace 4 ⁇ / b> A) in the manufacturing apparatus 300. Yes, installed in the connecting parts 7, 8, 9.
  • the gas mixing preventing means 11, 12, 13 are mainly injected with seal gas injection portions 11B, 12B, 13B for injecting a seal gas such as nitrogen along the opening surfaces of the inlet and outlet of the catalyst base 10 in each furnace. Exhaust portions 11A, 12A and 13A for exhausting the sealed gas to the outside are provided.
  • the catalyst base 10 placed on the mesh belt 6A is transported from the apparatus inlet to the furnace of the inlet purge unit 1, and after being treated in each furnace, from the outlet purge unit 5 through the apparatus outlet. It is transported outside the device.
  • CNTs Carbon nanostructure
  • the production method is not limited to CNTs.
  • various carbon nanostructures including a coil composed of sp2 hybrid orbits that can be grown on the catalyst surface by a CVD method, such as a coil can be produced.
  • Examples of the known literature include, for example, Japanese Unexamined Patent Application Publication No. 2009-127059 (diamond-like carbon), Japanese Unexamined Patent Application Publication No. 2013-86993 (graphene), Japanese Unexamined Patent Application Publication No. 2001-192204 (coil twist), and Japanese Unexamined Patent Application Publication No. 2003-2003. No. 277029 (fullerene).
  • CNT obtained by the production method of the present invention will be described as an example of the carbon nanostructure obtained by the production method of the present invention.
  • CNTs are directly obtained as aligned CNT aggregates by the production method of the present invention.
  • a physical, chemical or mechanical peeling method specifically, a method of peeling using an electric field, a magnetic field, centrifugal force or surface tension, or mechanical using tweezers or a cutter blade.
  • the CNT in the bulk state or the CNT in the powder state can be obtained by peeling off from the catalyst substrate by a method of peeling directly onto the catalyst substrate or a method of peeling off by pressure or heat such as suction by a vacuum pump.
  • the yield of CNTs by the production method of the present invention is preferably 2.4 mg / cm 2 or more, and more preferably 2.8 mg / cm 2 or more.
  • the carbon conversion efficiency is preferably 1.6% or more, and more preferably 2.8% or more.
  • “carbon conversion efficiency” means (weight of manufactured CNT) / (total carbon weight introduced into the furnace) ⁇ 100 [%], and “total carbon weight introduced into the furnace” Can be calculated from the above three values of the gas flow rate, the carbon concentration of the source gas, and the growth time under the assumption of an ideal gas approximation.
  • the carbon concentration in the raw material gas is preferably 1.3% or more, more preferably 2.0% or more, and further preferably 3.0% or more from the viewpoint of obtaining the effects of the present invention more sufficiently.
  • the upper limit of the carbon concentration tends to be proportional to the catalyst density in the furnace and can be increased to 380%.
  • the carbon concentration is usually preferably 60% or less, more preferably 30% or less, and particularly preferably 20% or less. If the carbon concentration is excessive with respect to the amount of catalyst density, carbon impurities such as amorphous carbon are generated, and these impurities cannot be ignored depending on the application.
  • CNTs may be single-walled carbon nanotubes or multi-walled carbon nanotubes, but according to the production method of the present invention, single-walled carbon nanotubes can be more suitably produced.
  • the average diameter (Av) of CNTs is preferably 0.5 nm or more, more preferably 1 nm or more, preferably 15 nm or less, and more preferably 10 nm or less.
  • the average diameter (Av) of the carbon nanotubes is usually determined by measuring 100 carbon nanotubes using a transmission electron microscope.
  • CNT is obtained as an aligned CNT aggregate by the production method of the present invention, and its specific surface area is preferably 600 m 2 / g or more, more preferably 800 m 2 / g or more, and 2500 m 2 / g. Or less, more preferably 1400 m 2 / g or less. Furthermore, when the CNTs are mainly opened, the specific surface area is preferably 1300 m 2 / g or more. In the present invention, the “specific surface area” refers to the BET specific surface area measured using the BET method.
  • the weight density of the aligned CNT aggregate 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, since the CNTs constituting the aligned CNT aggregate are weakened, it is easy to uniformly disperse the aligned CNT aggregate in a solvent or the like. become. Further, if the weight density is 0.002 g / cm 3 or more, the integrity of the aligned CNT aggregate can be improved, and the handling can be easily performed since it is possible to suppress the variation.
  • the aligned CNT aggregate has a high degree of orientation. Whether or not it has a high degree of orientation is as follows. To 3. It can be evaluated by at least one of the following methods.
  • 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.
  • the Hermann orientation coefficient is greater than 0 and less than 1, more preferably 0.25 or more and 1 or less.
  • the height (length) of the aligned CNT aggregate is preferably in the range of 10 ⁇ m to 10 cm.
  • the height is 10 ⁇ m or more, the degree of 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 the aligned CNT aggregate is preferably 2 or more, more preferably 4 or more.
  • the G / D ratio is an index generally used for evaluating the quality of CNTs.
  • the G band is a vibration mode derived from a hexagonal lattice structure of graphite, which is a cylindrical surface of CNT
  • 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.
  • the purity of the aligned CNT aggregate is usually 98% by mass or more, and preferably 99.9% by mass or more, even if no purification treatment is performed. Impurities are hardly mixed in the aligned CNT aggregate obtained by the production method of the present invention, and the various characteristics inherent to CNT can be fully exhibited.
  • the purity can be determined by elemental analysis using fluorescent X-rays.
  • Base material A flat plate of Fe—Cr alloy SUS430 (manufactured by JFE Steel Co., Ltd., Cr: 18% by mass) having a length of 500 mm ⁇ width of 500 mm and a thickness of 0.6 mm was prepared.
  • the surface roughness at a plurality of locations was measured using a laser microscope, the arithmetic average roughness Ra was approximately 0.063 ⁇ m.
  • a catalyst was formed on the above substrate by the following method. First, 1.9 g of aluminum tri-sec-butoxide was dissolved in 100 mL (78 g) of 2-propanol, and 0.9 g of triisopropanolamine was added and dissolved as a stabilizer to prepare an alumina film-forming coating agent. By the dip coating, the above-mentioned coating agent for forming an alumina film was applied onto the substrate in an environment of room temperature of 25 ° C. and relative humidity of 50%. As the coating conditions, the substrate was immersed, held for 20 seconds, the substrate was lifted at a pulling rate of 10 mm / second, and then air-dried for 5 minutes. Next, after heating for 30 minutes in 300 degreeC air environment, it cooled to room temperature. Thereby, an alumina film having a film thickness of 40 nm was formed on the substrate.
  • an iron film coating agent was applied on a substrate on which an alumina film was formed in an environment at room temperature of 25 ° C. and a relative humidity of 50%.
  • the substrate was immersed, held for 20 seconds, the substrate was lifted at a lifting speed of 3 mm / second, and then air-dried for 5 minutes.
  • the mixture was cooled to room temperature. Thereby, a catalyst generation film having a film thickness of 3 nm was formed.
  • Example 1 CNTs were manufactured by sequentially performing a formation process and a growth process in a batch growth furnace as shown in FIG. Using the catalyst substrate cut out to a size of 40 mm in length and 40 mm in width as the catalyst substrate, a formation process and a growth process were sequentially performed to produce CNTs on the substrate surface.
  • Table 1 shows the gas flow rate, gas composition, heater set temperature, and processing time in each step.
  • the raw material gas heating time was adjusted by changing the position where the catalyst base material was installed, and the base material position with the best balance between the yield and specific surface area of the produced CNTs was determined.
  • the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 2.
  • the “raw material gas heating time” is an approximate average time from when the raw material gas enters the in-furnace heating region until it reaches the catalyst substrate, and is obtained by the following equation.
  • Raw material gas heating time [min] (heating area volume [mL] upstream from the substrate) / ⁇ (gas flow rate [sccm]) ⁇ (furnace temperature [K]) ⁇ 1 / (273 [K]) ⁇
  • CPD is cyclopentadiene
  • pC 3 H 4 is methylacetylene (propyne)
  • VA vinylacetylene
  • 2B 2-butyne
  • aC 3 H 4 is propadiene (allene)
  • 13BD is 1,3-butadiene
  • t -PPL means t-piperylene
  • C 10 H 8 means naphthalene.
  • acetylenes are 1-butyne, diacetylene, phenylacetylene, 1,3-butadienes isoprene, c-piperylene, cyclopentadiene is methylcyclopentadiene, and allenes are 1,2-butadiene was detected, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than 10 ppm) as PAHs mainly composed of exhaust tar. Further, hydrogen, methane, ethylene, ethane, propylene, benzene, toluene, styrene and the like were detected as other components. In this experimental example, since the total volume concentration [B] of hydrocarbon B is less than 0.28%, it is referred to as “Comparative Example 1.” The characteristics of the CNT obtained under the above conditions were evaluated. The results are shown in Table 3.
  • Example 2 Using the same production apparatus as in Experimental Example 1, the composition of the raw material gas in the growth process was changed as shown in Table 4 to produce CNTs. Various conditions not described in Table 4 were the same as those in Experimental Example 1.
  • the concentration ratio ([A ′] / [B ′]) of C 2 H 2 and 13BD of the source gas is constant (0.4), and the concentration of carbon atoms contained in the source gas (hereinafter referred to as “carbon concentration”). ")."
  • carbon concentration concentration of carbon atoms contained in the source gas
  • the raw material gas heating time was adjusted by changing the position where the catalyst base was installed. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 5.
  • IP means isoprene
  • c-PPL means c-piperylene
  • 12BD means 1,2-butadiene.
  • diacetylene, methylvinylacetylene, and phenylacetylene were detected as acetylenes, and methylcyclopentadiene was detected as trace amounts (several ppm or less) as cyclopentadienes.
  • naphthalene was the most, and several tens ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than 10 ppm) as other components. Further, hydrogen, methane, ethylene, propylene, acetone, benzene, toluene, styrene and the like were detected as other components.
  • Example 2-1 in which C 2 H 2 concentration (hydrocarbon A concentration [A]) in the contact gas exceeds 0.1% and 13BD concentration (hydrocarbon B concentration [B]) is 0.28% or more
  • Examples 2-4 it was shown that the yield increased by about 1.4 to 2.5 times compared with Comparative Example 1 while maintaining the specific surface area at 1000 m 2 / g or more. It was also shown that the carbon conversion efficiency was improved by about 1.7 to 2.8 times.
  • Example 3 Using the same production apparatus as in Experimental Example 1, the composition of the raw material gas in the growth process was changed as shown in Table 7 to produce CNTs. Various conditions not described in Table 7 were the same as those in Experimental Example 2.
  • the carbon concentration was constant (6.0%), and the C 2 H 2 and 13BD concentration ratio ([A ′] / [B ′]) of the source gas was changed as shown in Table 7 to perform the production. It was.
  • the concentration of hydrogen H 2 added to the raw material gas was constant at 2.00%, and the concentration of the catalyst activation material H 2 O was constant at 0.02%.
  • the position where the catalyst base is installed is the same as in Experimental Example 2.
  • the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis.
  • the analysis results are shown in Table 8.
  • diacetylene, phenylacetylene and methylvinylacetylene were detected as acetylenes, and methylcyclopentadiene was detected as trace amounts (less than several ppm) as cyclopentadienes.
  • the exhaust tar main component PAHs naphthalene was the most, and several tens of ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm) as other components.
  • hydrogen, methane, ethylene, acetone, benzene, etc. were detected as other components.
  • Example 4 Using the same production apparatus as in Experimental Example 1, CNTs were produced using IP as the 1,3-butadienes (hydrocarbon B ′) with the composition of the raw material gas in the growth process as shown in Table 10. Various conditions not listed in Table 10 were the same as those in Experimental Example 1.
  • the carbon concentration was 6.0%, and the concentration ratio ([A ′] / [B ′]) of C 2 H 2 and IP of the source gas was 0.4.
  • the position where the catalyst base is installed is the same as in Experimental Example 2.
  • the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis.
  • the analysis results are shown in Table 11.
  • 1-butyne, methylvinylacetylene, and phenylacetylene were detected as acetylenes, and trace amounts (10 ppm or less) of methylcyclopentadiene were detected as cyclopentadienes.
  • the exhaust tar main component PAHs naphthalene was the most, and several tens of ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm) as other components. Further, hydrogen, methane, ethylene, propylene, benzene, toluene and the like were detected as other components.
  • Example 5 Using the same production apparatus as in Experimental Example 1, the composition of the raw material gas in the growth process is pC 3 H 4 , 1,3-butadienes (hydrocarbon B ′) as acetylenes (hydrocarbon A ′) as shown in Table 13. ) was used to produce CNTs using IP. The various conditions not listed in Table 13 were the same as in Experimental Example 1.
  • Manufacture was performed by setting the carbon concentration in the source gas to 6.0% and the concentration ratio ([A ′] / [B ′]) of pC 3 H 4 and IP in the source gas to 0.4.
  • the position where the catalyst base is installed is the same as in Experimental Example 2.
  • the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis.
  • the analysis results are shown in Table 14.
  • 1-butyne, methylvinylacetylene, and phenylacetylene were detected as acetylenes, and trace amounts (10 ppm or less) of methylcyclopentadiene were detected as cyclopentadienes.
  • the exhaust tar main component PAHs naphthalene was the most, and several tens of ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm) as other components. Further, hydrogen, methane, ethylene, propylene, benzene, toluene and the like were detected as other components.
  • Example 6 Using the same production apparatus as in Experimental Example 1, the composition of the raw material gas in the growth process was changed as shown in Table 16 to produce CNTs. Various conditions not described in Table 16 were the same as those in Experimental Example 1.
  • the carbon concentration is constant (4.0%), and the ratio [A ′] / [B ′] of the volume concentration [A ′] of C 2 H 2 of the source gas and the volume concentration [B ′] of 13BD.
  • Table 16 Were manufactured as shown in Table 16.
  • the concentration of hydrogen H 2 added to the raw material gas was constant at 1.33%, and the concentration of the catalyst activation material H 2 O was constant at 0.01%.
  • the position where the catalyst base is installed is the same as in Experimental Example 2.
  • the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis.
  • the analysis results are shown in Table 17.
  • diacetylene and phenylacetylene were detected as acetylenes, and methylcyclopentadiene was detected as trace amounts (less than several ppm) as cyclopentadienes.
  • methylcyclopentadiene was detected as trace amounts (less than several ppm) as cyclopentadienes.
  • PAHs acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm).
  • hydrogen, methane, ethylene, benzene and the like were detected as other components.
  • Example 7 Using the same production equipment as in Experimental Example 1, the composition of the raw material gas in the growth process is as shown in Table 19 to produce CNTs by adding cyclopentene (CPE) as hydrocarbon C ′ in addition to C 2 H 2 and 13BD. did. Various conditions not described in Table 19 were the same as those in Experimental Example 1.
  • CPE cyclopentene
  • the carbon concentration in the raw material gas was constant (6.0%), and the concentration ratio of C 2 H 2 and 13BD ([A ′] / [B ′]) and the concentration of CPE in the raw material gas are shown in Table 19.
  • the production was carried out by changing as shown in FIG.
  • the position where the catalyst base is installed is the same as in Experimental Example 2.
  • the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis.
  • the analysis results are shown in Table 20.
  • trace amounts (10 ppm or less) of diacetylene and phenylacetylene as acetylenes and methylcyclopentadiene as cyclopentadiene were detected.
  • As other components of the exhaust tar main component PAHs, acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm). Further, hydrogen, methane, ethylene, cyclopentene, benzene and the like were detected as other components.
  • Example 8 CNTs were manufactured by sequentially performing a formation process and a growth process in a batch type growth furnace as shown in FIG. A CNT was produced on the surface of the base material by sequentially performing a formation process and a growth process using the above-mentioned catalyst base material cut into a size of 40 mm long ⁇ 120 mm wide as a catalyst base material.
  • Table 22 shows the gas flow rate, gas composition, heater set temperature, and processing time in each step.
  • the carbon concentration was 6.0%, and the concentration ratio ([A ′] / [B ′]) of C 2 H 2 and 13BD of the raw material gas was 0.4.
  • the raw material gas heating time was adjusted by changing the position where the catalyst base was installed. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 23.
  • diacetylene, methylvinylacetylene, and phenylacetylene were detected as acetylenes, and methylcyclopentadiene was detected as a trace amount (less than several ppm) as cyclopentadienes, respectively.
  • Naphthalene was the most abundant and several tens of ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm) as other components.
  • hydrogen, methane, ethylene, propylene, benzene, toluene and the like were detected as other components.
  • Example 9 In the continuous growth furnace as shown in FIG. 3, an aligned CNT aggregate was manufactured by continuously performing a process including a formation process and a growth process.
  • the above-mentioned catalyst base material was placed on the mesh belt of the production apparatus as it was (length: 500 mm ⁇ width: 500 mm), and an aligned CNT aggregate was produced on the base material while changing the conveying speed of the mesh belt.
  • Table 25 shows the conditions of each part of the manufacturing apparatus.
  • the equipment is operated under the same conditions as in the case of producing aligned CNT aggregates, except that a probe for gas sampling is installed in the growth unit 3 in the vicinity of the position where the catalyst substrate passes, and the catalyst substrate is not allowed to pass.
  • a probe for gas sampling is installed in the growth unit 3 in the vicinity of the position where the catalyst substrate passes, and the catalyst substrate is not allowed to pass.
  • a high-quality carbon nanostructure can be produced with high efficiency.

Abstract

The present invention is a method for producing a carbon nanostructure with which a high quality carbon nanostructure can be produced with high efficiency by supplying material gas to a catalyst and growing the carbon nanostructure by chemical vapor deposition. This method for producing a carbon nanostructure is characterized in that (1) a gas X which originates from the material gas and comes into contact with the catalyst comprises hydrocarbon A having at least one acetylene backbone and hydrocarbon B having at least one 1,3-butadiene backbone, a total volume concentration [A] of the hydrocarbon A being over 0.1% and a total volume concentration [B] of the hydrocarbon B being 0.28% or more, or in that (2) the material gas comprises hydrocarbon A' having at least one acetylene backbone and hydrocarbon B' having at least one 1,3-butadiene backbone.

Description

炭素ナノ構造体の製造方法Method for producing carbon nanostructure
　本発明は、炭素ナノ構造体の製造方法に関する。 The present invention relates to a method for producing a carbon nanostructure.
　炭素ナノ構造体がナノテクノロジーの中核物質として注目を集めている。本発明において「炭素ナノ構造体」とは、炭素原子から構成されるナノサイズの物質であり、例えば、コイル状のカーボンナノコイル、チューブ状のカーボンナノチューブ（以下、「ＣＮＴ」とも称する。）、ＣＮＴが捩れを有したカーボンナノツイスト、ＣＮＴにビーズが形成されたビーズ付ＣＮＴ、ＣＮＴが多数林立したカーボンナノブラシ、球殻状のフラーレン、グラフェン、ダイヤモンドライクカーボン薄膜などがある。これら炭素ナノ構造体は、化学気相成長法を用いて金属（触媒）表面上にｓｐ２混成軌道からなる炭素を含むナノ構造体を析出させるという観点において共通しており、製造方法には多くのアナロジーが適応できる。 Carbon nanostructures are attracting attention as the core material of nanotechnology. In the present invention, the “carbon nanostructure” is a nano-sized substance composed of carbon atoms. For example, a coiled carbon nanocoil, a tube-shaped carbon nanotube (hereinafter also referred to as “CNT”), There are carbon nano twists in which CNTs are twisted, CNTs with beads in which beads are formed on CNTs, carbon nano brushes with many CNTs, spherical shell fullerenes, graphene, diamond-like carbon thin films, and the like. These carbon nanostructures are common in terms of depositing nanostructures containing carbon consisting of sp2 hybrid orbitals on the metal (catalyst) surface using chemical vapor deposition, and there are many production methods. Analogy can be applied.
　これまでに、原料ガスを触媒に供給し、化学気相成長法（以下、「ＣＶＤ法」とも称する。）によって炭素ナノ構造体を成長させる方法が知られている。この方法では、約５００℃～１０００℃の高温雰囲気下で炭素化合物を含む原料ガスを触媒の金属微粒子に供給する。当該方法において、触媒の種類及び配置、原料ガスの種類、反応条件などを様々に変化させることで、種々の炭素ナノ構造体を製造することができる。 So far, a method of growing a carbon nanostructure by a chemical vapor deposition method (hereinafter also referred to as “CVD method”) by supplying a raw material gas to a catalyst is known. In this method, a raw material gas containing a carbon compound is supplied to the metal fine particles of the catalyst in a high temperature atmosphere of about 500 ° C. to 1000 ° C. In this method, various carbon nanostructures can be produced by variously changing the type and arrangement of the catalyst, the type of raw material gas, the reaction conditions, and the like.
　たとえば、特許文献１には、原料ガスとしてメタン（ＣＨ４）やエチレン（Ｃ２Ｈ４）を用い、触媒と接触するガスにアルキンを含む条件にて、ＣＶＤ法によりＣＮＴを製造する方法が記載されている。また、特許文献２には、原料ガスとしてメタン、エチレン、アセチレン（Ｃ２Ｈ２）等の炭化水素ガスを用い、原料ガスを触媒に吹き付けてＣＶＤ法によりＣＮＴを製造する方法が記載されている。 For example, Patent Document 1 describes a method for producing CNTs by a CVD method using methane (CH 4 ) or ethylene (C 2 H 4 ) as a source gas and containing alkyne in the gas in contact with the catalyst. Has been. Patent Document 2 describes a method of producing CNTs by a CVD method by using a hydrocarbon gas such as methane, ethylene, acetylene (C 2 H 2 ), or the like as a source gas and spraying the source gas on a catalyst. .
　ＣＶＤ法によるＣＮＴの製造技術は、単層カーボンナノチューブ（ＳＷＣＮＴ）と多層カーボンナノチューブ（ＭＷＣＮＴ）とのいずれも製造可能である上、触媒を担持した基板を用いることで、基板面に垂直に配向した多数のＣＮＴを製造することができる、という利点を備えている。また、原料ガスと共に水等の触媒賦活物質を触媒に接触させるスーパーグロース法が開発されて以降、ＣＮＴの大量生産に適したものとして注目されている。 The CNT manufacturing technology by the CVD method can manufacture both single-walled carbon nanotubes (SWCNT) and multi-walled carbon nanotubes (MWCNT), and is oriented perpendicular to the substrate surface by using a substrate carrying a catalyst. It has the advantage that a large number of CNTs can be produced. In addition, since the development of a super-growth method in which a catalyst activator such as water is brought into contact with a catalyst together with a raw material gas, it has attracted attention as being suitable for mass production of CNTs.
　ところで、ＣＶＤ法によるＣＮＴ合成の化学反応メカニズムについて、その全容は未だ明確になっていないが、アセチレン（アルキン類）がＣＮＴ合成に有効な分子（すなわち、実際にＣＮＴ前駆体として機能する分子）であるとの研究結果が複数報告されている。 By the way, the chemical reaction mechanism of CNT synthesis by CVD method has not been clarified yet, but acetylene (alkynes) is an effective molecule for CNT synthesis (that is, a molecule that actually functions as a CNT precursor). Several research results have been reported.
特表２０１２－５３０６６３号公報Special table 2012-530663 gazette 国際公開第０５／１１８４７３号International Publication No. 05/118473
　しかしながら、ＣＶＤ法によるＣＮＴの製造において、触媒に供給するアセチレンの体積濃度を増加させてもある濃度（０．５～１．５％程度）以上では、合成されるＣＮＴ収量はほぼ飽和してしまうことが知られていた。また、合成されるＣＮＴの収量と品質（比表面積や後述のＧ／Ｄ）とは逆相関の関係にあり、収量を高くしようと飽和体積濃度以上のアセチレンを触媒に供給しても、収量はあまり上がらずに、比表面積及びＧ／Ｄは急激に低下するという問題があった。そのため、品質を維持しつつ収量を上げることが可能なＣＶＤ法による製造技術が望まれており、この点において、ＣＮＴ合成に有効な分子としてアセチレンを単に含むガスを触媒に供給する従来技術は不十分であった。 However, in the production of CNTs by the CVD method, even if the volume concentration of acetylene supplied to the catalyst is increased above a certain concentration (about 0.5 to 1.5%), the synthesized CNT yield is almost saturated. It was known. In addition, the yield and quality (specific surface area and G / D described later) of the synthesized CNT have an inverse correlation, and even if acetylene having a saturated volume concentration or higher is supplied to the catalyst to increase the yield, the yield is There was a problem that the specific surface area and G / D decreased rapidly without increasing so much. Therefore, there is a demand for a manufacturing technique based on the CVD method that can increase the yield while maintaining the quality. In this respect, the conventional technique that simply supplies the catalyst with a gas that simply contains acetylene as a molecule effective for CNT synthesis is not possible. It was enough.
　そこで本発明は、上記課題に鑑み、高品質な炭素ナノ構造体を高効率に製造可能な炭素ナノ構造体の製造方法を提供することを目的とする。 Therefore, in view of the above problems, an object of the present invention is to provide a method for producing a carbon nanostructure capable of producing a high-quality carbon nanostructure with high efficiency.
　この目的を達成すべく本発明者は鋭意検討の結果、以下の知見を得た。すなわち、本発明者は、原料ガスではなく実際に触媒に接触するガス（以下、単に「接触ガス」とも称する。）の組成に着目した。具体的には、ＣＶＤ法において、従来用いられている原料ガスの一種であるエチレンが熱分解されることで生成する多数の炭化水素ガスの中から、アセチレン以外のＣＮＴ前駆体を新規に特定した。さらに、それらのＣＮＴ前駆体をそれぞれ所定の体積濃度で混合したガスを触媒に接触させることでＣＮＴ合成の効率を大きく向上できることを見出した。具体的には、アセチレン骨格を少なくとも１つ有する炭化水素Ａと、１，３－ブタジエン骨格を少なくとも１つ有する炭化水素Ｂと、を、所定の体積濃度で含む混合ガスが有効であることを見出した。 In order to achieve this object, the present inventor obtained the following knowledge as a result of intensive studies. That is, the present inventor paid attention to the composition of the gas that actually contacts the catalyst (hereinafter also simply referred to as “contact gas”), not the raw material gas. Specifically, in the CVD method, CNT precursors other than acetylene were newly identified from a large number of hydrocarbon gases produced by the thermal decomposition of ethylene, which is one of the raw material gases conventionally used. . Furthermore, it has been found that the efficiency of CNT synthesis can be greatly improved by bringing a gas obtained by mixing these CNT precursors at a predetermined volume concentration into contact with the catalyst. Specifically, it has been found that a mixed gas containing hydrocarbon A having at least one acetylene skeleton and hydrocarbon B having at least one 1,3-butadiene skeleton in a predetermined volume concentration is effective. It was.
　また、接触ガス中の上記ＣＮＴ前駆体のガス成分をそれぞれ所定の体積濃度以上とすることができる原料ガスの組成をも特定した。以上の知見から、高品質な炭素ナノ構造体を高効率に製造できる方法を確立し、本発明を完成するに至った。 In addition, the composition of the raw material gas capable of setting the gas components of the CNT precursor in the contact gas to a predetermined volume concentration or higher was also specified. From the above knowledge, a method capable of producing a high-quality carbon nanostructure with high efficiency has been established, and the present invention has been completed.
　このように本発明は、従来のＣＮＴ製造における触媒と接触するガスの組成を単に規定したものではない。本発明において用いられる原料ガスは、特許文献１、２とは異なり、接触ガスも特許文献１とは異なる。特許文献２は、何ら接触ガスに着目するものではない。 Thus, the present invention does not merely specify the composition of the gas that comes into contact with the catalyst in conventional CNT production. The source gas used in the present invention is different from Patent Documents 1 and 2, and the contact gas is also different from Patent Document 1. Patent Document 2 does not focus on contact gas at all.
　上記知見に基づき完成した本発明の要旨構成は以下のとおりである。
　本発明は、
　原料ガスを触媒に供給し、化学気相成長法によって炭素ナノ構造体を成長させる炭素ナノ構造体の製造方法であって、
　前記原料ガスに由来し、前記触媒に接触するガスＸが、アセチレン骨格を少なくとも１つ有する炭化水素Ａと、１，３－ブタジエン骨格を少なくとも１つ有する炭化水素Ｂと、を含み、
　前記炭化水素Ａの合計体積濃度［Ａ］が０．１％超過、前記炭化水素Ｂの合計体積濃度［Ｂ］が０．２８％以上であることを特徴とする。 The gist configuration of the present invention completed based on the above findings is as follows.
The present invention
A method for producing a carbon nanostructure in which a raw material gas is supplied to a catalyst and a carbon nanostructure is grown by chemical vapor deposition,
Gas X derived from the raw material gas and contacting the catalyst contains hydrocarbon A having at least one acetylene skeleton and hydrocarbon B having at least one 1,3-butadiene skeleton,
The total volume concentration [A] of the hydrocarbon A exceeds 0.1%, and the total volume concentration [B] of the hydrocarbon B is 0.28% or more.
　本発明において、前記ガスＸは、０．１≦［Ａ］／［Ｂ］≦８を満たすことが好ましい。 In the present invention, the gas X preferably satisfies 0.1 ≦ [A] / [B] ≦ 8.
　本発明において、前記ガスＸが、触媒賦活物質及び／又は水素分子をさらに含むことが好ましい。 In the present invention, it is preferable that the gas X further includes a catalyst activation material and / or a hydrogen molecule.
　本発明において、前記ガスＸが、シクロペンタジエン骨格を少なくとも１つ有する炭化水素Ｃをさらに含むことが好ましい。 In the present invention, it is preferable that the gas X further includes hydrocarbon C having at least one cyclopentadiene skeleton.
　また、本発明は、
　原料ガスを触媒に供給し、化学気相成長法によって炭素ナノ構造体を成長させる炭素ナノ構造体の製造方法であって、
　前記原料ガスが、アセチレン骨格を少なくとも１つ有する炭化水素Ａ’と、１，３－ブタジエン骨格を少なくとも１つ有する炭化水素Ｂ’と、を含むことを特徴とする。 The present invention also provides:
A method for producing a carbon nanostructure in which a raw material gas is supplied to a catalyst and a carbon nanostructure is grown by chemical vapor deposition,
The source gas contains hydrocarbon A ′ having at least one acetylene skeleton and hydrocarbon B ′ having at least one 1,3-butadiene skeleton.
　本発明において、前記炭化水素Ａ’の合計体積濃度を［Ａ’］、前記炭化水素Ｂ’の合計体積濃度を［Ｂ’］としたときに、前記原料ガスが、０．１≦［Ａ’］／［Ｂ’］≦６を満たすことが好ましい。 In the present invention, when the total volume concentration of the hydrocarbon A ′ is [A ′] and the total volume concentration of the hydrocarbon B ′ is [B ′], the raw material gas is 0.1 ≦ [A ′. ] / [B ′] ≦ 6 is preferably satisfied.
　本発明において、前記原料ガスが、触媒賦活物質及び／又は水素分子をさらに含むことが好ましい。 In the present invention, it is preferable that the source gas further includes a catalyst activation material and / or a hydrogen molecule.
　本発明において、前記原料ガスが、炭素数５の炭素環を少なくとも１つ有する炭化水素Ｃ’をさらに含むことが好ましい。 In the present invention, it is preferable that the source gas further includes a hydrocarbon C ′ having at least one carbon ring having 5 carbon atoms.
　本発明において、前記触媒が基材表面に担持されており、前記原料ガスをガスシャワーによって前記触媒に供給することが好ましい。 In the present invention, it is preferable that the catalyst is supported on the surface of a base material, and the raw material gas is supplied to the catalyst by a gas shower.
　本発明において、前記炭素ナノ構造体がカーボンナノチューブであることが好ましい。 In the present invention, the carbon nanostructure is preferably a carbon nanotube.
　本発明の炭素ナノ構造体の製造方法によれば、高品質な炭素ナノ構造体を高効率に製造することができる。 According to the method for producing a carbon nanostructure of the present invention, a high-quality carbon nanostructure can be produced with high efficiency.
本発明に適用可能なＣＮＴ製造装置の構成の一例を示す模式図である。It is a schematic diagram which shows an example of a structure of the CNT manufacturing apparatus applicable to this invention. 本発明に適用可能なＣＮＴ製造装置の構成の別の一例を示す模式図である。It is a schematic diagram which shows another example of a structure of the CNT manufacturing apparatus applicable to this invention. 本発明に適用可能なＣＮＴ製造装置の構成の更に別の一例を示す模式図である。It is a schematic diagram which shows another example of a structure of the CNT manufacturing apparatus applicable to this invention.
　以下、図面を参照しつつ本発明の炭素ナノ構造体の製造方法の実施形態を説明する。本実施形態の製造方法では、触媒層を表面に有する基材（以下、「触媒基材」という。）に原料ガスを供給し、化学気相成長法によって触媒層上にＣＮＴを成長させる。触媒層上には多数のＣＮＴが基材に略垂直な方向に配向して集合体を形成する。本発明において、これを「ＣＮＴ配向集合体」という。 Hereinafter, embodiments of the method for producing a carbon nanostructure of the present invention will be described with reference to the drawings. In the manufacturing method of the present embodiment, a raw material gas is supplied to a substrate having a catalyst layer on the surface (hereinafter referred to as “catalyst substrate”), and CNTs are grown on the catalyst layer by chemical vapor deposition. On the catalyst layer, a large number of CNTs are oriented in a direction substantially perpendicular to the substrate to form an aggregate. In the present invention, this is referred to as “CNT aligned aggregate”.
　（基材）
　触媒基材に用いる基材は、例えば平板状の部材であり、５００℃以上の高温でも形状を維持できるものが好ましい。具体的には、鉄、ニッケル、クロム、モリブデン、タングステン、チタン、アルミニウム、マンガン、コバルト、銅、銀、金、白金、ニオブ、タンタル、鉛、亜鉛、ガリウム、インジウム、ゲルマニウム、及びアンチモン等の金属、並びにこれらの金属を含む合金及び酸化物、又はシリコン、石英、ガラス、マイカ、グラファイト、及びダイヤモンド等の非金属、並びにセラミック等が挙げられる。金属材料はシリコン及びセラミックと比較して、低コスト且つ加工が容易であるから好ましく、特に、Ｆｅ－Ｃｒ（鉄－クロム）合金、Ｆｅ－Ｎｉ（鉄－ニッケル）合金、Ｆｅ－Ｃｒ－Ｎｉ（鉄－クロム－ニッケル）合金等は好適である。 (Base material)
The base material used for the catalyst base material is, for example, a flat plate-like member, and a material that can maintain the shape even at a high temperature of 500 ° C. or higher is preferable. 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, or nonmetals such as silicon, quartz, glass, mica, graphite, and diamond, and ceramics. The metal material is preferable because it is low in cost and easy to process as compared with silicon and ceramic, and in particular, Fe—Cr (iron-chromium) alloy, Fe—Ni (iron-nickel) alloy, Fe—Cr—Ni ( An iron-chromium-nickel alloy or the like is preferred.
　基材の形態は、平板状、薄膜状、ブロック状、ワイヤー状、メッシュ状あるいは粒子・微粒子・粉末状等が挙げられ、特に体積の割に表面積を大きくとれる形状がＣＮＴを大量に製造する場合において有利である。平板状の基材の厚さに特に制限はなく、例えば数μｍ程度の薄膜から数ｃｍ程度までのものを用いることができる。平板状の基材の厚さとしては、好ましくは、０．０５ｍｍ以上且つ３ｍｍ以下である。 Examples of the form of the substrate include a flat plate shape, a thin film shape, a block shape, a wire shape, a mesh shape, or a particle / fine particle / powder shape. In particular, a shape that can take a large surface area for a large volume produces a large amount of CNT. Is advantageous. There is no restriction | limiting in particular in the thickness of a flat base material, For example, the thing from about several micrometers thin film to about several cm can be used. The thickness of the flat substrate is preferably 0.05 mm or more and 3 mm or less.
　（触媒）
　触媒基材において、基材上（基材上に浸炭防止層を備える場合には当該浸炭防止層の上）には、触媒層が形成されている。触媒としては、ＣＮＴの製造が可能であればよく、例えば、鉄、ニッケル、コバルト、モリブデン、及び、これらの塩化物及び合金が挙げられる。これらの複数が複合化あるいは層状になっていてもよく、これらが、さらにアルミニウム、アルミナ、チタニア、窒化チタン、酸化シリコンと複合化あるいは層状になっていてもよい。例えば、鉄－モリブデン薄膜、アルミナ－鉄薄膜、アルミナ－コバルト薄膜、及びアルミナ－鉄－モリブデン薄膜、アルミニウム－鉄薄膜、アルミニウム－鉄－モリブデン薄膜等を例示することができる。触媒の存在量としては、ＣＮＴの製造が可能な範囲であればよく、例えば、鉄を用いる場合、製膜厚さは、０．１ｎｍ以上且つ１００ｎｍ以下が好ましく、０．５ｎｍ以上且つ５ｎｍ以下がさらに好ましく、０．８ｎｍ以上且つ２ｎｍ以下が特に好ましい。 (catalyst)
In the catalyst base material, a catalyst layer is formed on the base material (when the carburization prevention layer is provided on the base material, on the carburization prevention layer). The catalyst may be any as long as it can produce CNTs, and examples thereof include iron, nickel, cobalt, molybdenum, and chlorides and alloys thereof. A plurality of these may be combined or layered, and these may be further combined or layered with aluminum, alumina, titania, titanium nitride, or silicon oxide. For example, iron-molybdenum thin film, alumina-iron thin film, alumina-cobalt thin film, alumina-iron-molybdenum thin film, aluminum-iron thin film, 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 film thickness is preferably 0.1 nm or more and 100 nm or less, and 0.5 nm or more and 5 nm or less. More preferably, it is 0.8 nm or more and 2 nm or less.
　基材表面への触媒層の形成は、ウェットプロセス又はドライプロセス（スパッタリング蒸着法等）のいずれを適用してもよい。成膜装置の簡便さ（真空プロセスを要しない）、スループットの速さ、原材料費の安さ等の観点から、ウェットプロセスを適用するのが好ましい。 For the formation of the catalyst layer on the substrate surface, either a wet process or a dry process (such as sputtering deposition) may be applied. It is preferable to apply a wet process from the viewpoints of the convenience of the film formation apparatus (no vacuum process is required), the throughput speed, the low raw material costs, and the like.
　（触媒形成ウェットプロセス）
　触媒層を形成するウェットプロセスは、触媒となる元素を含んだ金属有機化合物及び／又は金属塩を有機溶剤に溶解したコーティング剤を基材上へ塗布する工程と、その後加熱する工程から成る。コーティング剤には金属有機化合物及び金属塩の過度な縮合重合反応を抑制するための安定剤を添加してもよい。 (Catalyst formation wet process)
The wet process for forming the catalyst layer includes a step of applying a coating agent obtained by dissolving a metal organic compound and / or metal salt containing an element serving as a catalyst in an organic solvent, and then a step of heating. You may add the stabilizer for suppressing the excessive condensation polymerization reaction of a metal organic compound and a metal salt to a coating agent.
　塗布工程としては、スプレー、ハケ塗り等により塗布する方法、スピンコーティング、及びディップコーティング等、いずれの方法を用いてもよいが、生産性及び膜厚制御の観点からディップコーティングが好ましい。 As the coating step, any method such as spray coating, brush coating, spin coating, and dip coating may be used, but dip coating is preferred from the viewpoint of productivity and film thickness control.
　塗布工程の後に加熱工程を行なうことが好ましい。加熱することで金属有機化合物及び金属塩の加水分解及び縮重合反応が開始され、金属水酸化物及び／又は金属酸化物を含む硬化皮膜が基材表面に形成される。加熱温度はおよそ５０℃以上且つ４００℃以下の範囲で、加熱時間は５分以上且つ３時間以下の範囲で、形成する触媒薄膜の種類によって適宜調整することが好ましい。 It is preferable to perform a heating process after the coating process. By heating, hydrolysis and polycondensation reaction of the metal organic compound and the metal salt are started, and a cured film containing the metal hydroxide and / or the metal oxide is formed on the substrate surface. The heating temperature is preferably in the range of about 50 ° C. or more and 400 ° C. or less, and the heating time is preferably in the range of 5 minutes or more and 3 hours or less.
　例えば、触媒としてアルミナ－鉄薄膜を形成する場合、アルミナ膜を形成した後に鉄薄膜を形成する。 For example, when an alumina-iron thin film is formed as a catalyst, the iron thin film is formed after the alumina film is formed.
　アルミナ薄膜を形成するための金属有機化合物としては、アルミニウムトリメトキシド、アルミニウムトリエトキシド、アルミニウムトリ－ｎ－プロポキシド、アルミニウムトリ－ｉ－プロポキシド、アルミニウムトリ－ｎ－ブトキシド、アルミニウムトリ－ｓｅｃ－ブトキシド、アルミニウムトリ－ｔｅｒｔ－ブトキシド等のアルミニウムアルコキシドが挙げられる。アルミニウムを含む金属有機化合物としては他に、トリス（アセチルアセトナト）アルミニウム（ＩＩＩ）等の錯体が挙げられる。また、アルミナ薄膜を形成するための金属塩としては、硫酸アルミニウム、塩化アルミニウム、硝酸アルミニウム、臭化アルミニウム、よう化アルミニウム、乳酸アルミニウム、塩基性塩化アルミニウム、塩基性硝酸アルミニウム等が挙げられる。これらのなかでも、アルミニウムアルコキシドを用いることが好ましい。これらは、それぞれ単独で、又は２種以上の混合物として用いることができる。 Examples of the metal organic compound for forming the alumina thin film include aluminum trimethoxide, aluminum triethoxide, aluminum tri-n-propoxide, aluminum tri-i-propoxide, aluminum tri-n-butoxide, aluminum tri-sec. -Aluminum alkoxides such as butoxide and aluminum tri-tert-butoxide. Other examples of the metal organic compound containing aluminum include complexes such as tris (acetylacetonato) aluminum (III). Examples of the metal salt for forming the alumina thin film include aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum bromide, aluminum iodide, aluminum lactate, basic aluminum chloride, basic aluminum nitrate and the like. Among these, it is preferable to use aluminum alkoxide. These can be used alone or as a mixture of two or more.
　鉄薄膜を形成するための金属有機化合物としては、鉄ペンタカルボニル、フェロセン、アセチルアセトン鉄（ＩＩ）、アセチルアセトン鉄（ＩＩＩ）、トリフルオロアセチルアセトン鉄（ＩＩ）、トリフルオロアセチルアセトン鉄（ＩＩＩ）等が挙げられる。また、鉄薄膜を形成するための金属塩としては、例えば、硫酸鉄、硝酸鉄、リン酸鉄、塩化鉄、臭化鉄等の無機酸鉄、酢酸鉄、シュウ酸鉄、クエン酸鉄、乳酸鉄等の有機酸鉄等が挙げられる。これらのなかでも、有機酸鉄を用いることが好ましい。これらは、それぞれ単独で、又は２種以上の混合物として用いることができる。 Examples of the metal organic compound for forming the iron thin film include iron pentacarbonyl, ferrocene, acetylacetone iron (II), acetylacetone iron (III), trifluoroacetylacetone iron (II), trifluoroacetylacetone iron (III) and the like. . Examples of metal salts for forming an iron thin film include iron sulfate, iron nitrate, iron phosphate, iron chloride, iron bromide and other inorganic acid iron, iron acetate, iron oxalate, iron citrate, lactic acid Examples thereof include organic acid irons such as iron. Among these, it is preferable to use organic acid iron. These can be used alone or as a mixture of two or more.
　安定剤としては、β－ジケトン類及びアルカノールアミン類からなる群より選ばれる少なくとも１つであることが好ましい。これらの化合物は単独で用いてもよいし、２種類以上を混合して用いてもよい。β－ジケトン類ではアセチルアセトン、アセト酢酸メチル、アセト酢酸エチル、ベンゾイルアセトン、ジベンゾイルメタン、ベンゾイルトリフルオルアセトン、フロイルアセトン、及びトリフルオルアセチルアセトン等があるが、特にアセチルアセトン及びアセト酢酸エチルを用いることが好ましい。アルカノールアミン類ではモノエタノールアミン、ジエタノールアミン、トリエタノールアミン、Ｎ－メチルジエタノールアミン、Ｎ－エチルジエタノールアミン、Ｎ，Ｎ－ジメチルアミノエタノール、ジイソプロパノールアミン、トリイソプロパノールアミン等があるが、第２級又は第３級アルカノールアミンであることが好ましい。 The stabilizer is preferably at least one selected from the group consisting of β-diketones and alkanolamines. These compounds may be used alone or in combination of two or more. Examples of β-diketones include acetylacetone, methyl acetoacetate, ethyl acetoacetate, benzoylacetone, dibenzoylmethane, benzoyltrifluoroacetone, furoylacetone, and trifluoroacetylacetone. preferable. Examples of alkanolamines include monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylaminoethanol, diisopropanolamine, and triisopropanolamine. A secondary alkanolamine is preferred.
　有機溶剤としては、アルコール、グリコール、ケトン、エーテル、エステル類、炭化水素類等の種々の有機溶剤が使用できるが、金属有機化合物及び金属塩の溶解性が良いことから、アルコール又はグリコールを用いることが好ましい。これらの有機溶剤は単独で用いてもよいし、２種類以上を混合して用いてもよい。アルコールとしては、メタノール、エタノール、イソプロピルアルコール等が、取り扱い性、保存安定性といった点で好ましい。 As the organic solvent, various organic solvents such as alcohols, glycols, ketones, ethers, esters, hydrocarbons and the like can be used, but alcohols or glycols are used because of the good solubility of metal organic compounds and metal salts. Is preferred. These organic solvents may be used alone or in combination of two or more. As the alcohol, methanol, ethanol, isopropyl alcohol, and the like are preferable in terms of handling properties and storage stability.
　前記コーティング剤中の前記金属有機化合物及び／又は金属塩の含有量としては、通常、０．０５質量％以上且つ０．５質量％以下、好ましくは０．１質量％以上且つ０．５質量％以下である。 The content of the metal organic compound and / or metal salt in the coating agent is usually 0.05% by mass or more and 0.5% by mass or less, preferably 0.1% by mass or more and 0.5% by mass. It is as follows.
　（フォーメーション工程）
　本発明の製造方法では、成長工程の前にフォーメーション工程を行なうことが好ましい。フォーメーション工程とは、触媒の周囲環境を還元ガス環境とすると共に、触媒及び還元ガスの少なくとも一方を加熱する工程である。この工程により、触媒の還元、ＣＮＴの成長に適合した状態としての触媒の微粒子化促進、触媒の活性向上の少なくとも１つの効果が現れる。例えば、触媒がアルミナ－鉄薄膜である場合、鉄触媒は還元されて微粒子化し、アルミナ層上にナノメートルサイズの鉄微粒子が多数形成される。これにより触媒はＣＮＴ配向集合体の製造に好適な状態となる。この工程を省略してもＣＮＴを製造することは可能であるが、この工程を行なうことでＣＮＴ配向集合体の製造量及び品質を飛躍的に向上させることができる。 (Formation process)
In the production method of the present invention, it is preferable to perform the formation step before the growth step. The formation step is a step of heating at least one of the catalyst and the reducing gas while setting the environment surrounding the catalyst as the reducing gas environment. By this step, at least one of the effects of reducing the catalyst, promoting the atomization of the catalyst in a state suitable for the growth of CNT, and improving the activity of the catalyst appears. For example, when the catalyst is an alumina-iron thin film, the iron catalyst is reduced into fine particles, and a large number of nanometer-sized iron fine particles are formed on the alumina layer. As a result, the catalyst is in a state suitable for the production of the aligned CNT aggregate. Even if this step is omitted, CNTs can be produced. However, by performing this step, the production amount and quality of the aligned CNT aggregate can be dramatically improved.
　還元性を有するガス（還元ガス）としては、ＣＮＴの製造が可能なものを用いればよく、例えば水素ガス、アンモニア、及び水蒸気、並びにそれらの混合ガスを適用することができる。また、水素ガスをヘリウムガス、アルゴンガス、及び窒素ガス等の不活性ガスと混合した混合ガスでもよい。還元ガスは、フォーメーション工程の他、適宜成長工程に用いてもよい。 As the reducible gas (reducing gas), a gas capable of producing CNTs may be used. For example, hydrogen gas, ammonia, water vapor, and a mixed gas thereof can be applied. Alternatively, a mixed gas obtained by mixing hydrogen gas with an inert gas such as helium gas, argon gas, and nitrogen gas may be used. The reducing gas may be used in the growth process as appropriate in addition to the formation process.
　（成長工程）
　成長工程とは、触媒の周囲環境を原料ガス環境とすると共に、触媒及び原料ガスの少なくとも一方を加熱することにより、触媒上にＣＮＴ配向集合体を成長させる工程である。高品質なＣＮＴを成長させる観点からは、少なくとも触媒を加熱することが好ましい。加熱の温度は、４００℃以上且つ１１００℃以下が好ましい。成長工程は、触媒基材を収容するＣＮＴ成長炉内に、不活性ガスと、随意に還元ガス及び／又は触媒賦活物質と、を含む原料ガスを導入して行う。 (Growth process)
The growth step is a step of growing an aligned CNT aggregate on the catalyst by setting the surrounding environment of the catalyst as a raw material gas environment and heating at least one of the catalyst and the raw material gas. From the viewpoint of growing high-quality CNTs, it is preferable to heat at least the catalyst. The heating temperature is preferably 400 ° C. or higher and 1100 ° C. or lower. The growth step is performed by introducing a raw material gas containing an inert gas and, optionally, a reducing gas and / or a catalyst activation material into a CNT growth furnace containing the catalyst substrate.
　＜接触ガス＞
　本発明は、成長工程で触媒に接触するガスＸに１つの大きな特徴を有する。当該ガスＸは、原料ガスが分解された各種炭化水素ガスと、分解されることなく触媒に到達した原料ガスと、不活性ガスと、随意に含まれる還元ガス及び／又は触媒賦活物質とからなる。 <Contact gas>
The present invention has one major feature in the gas X that contacts the catalyst during the growth process. The gas X is composed of various hydrocarbon gases obtained by decomposing the raw material gas, a raw material gas that has reached the catalyst without being decomposed, an inert gas, and a reducing gas and / or a catalyst activation material optionally contained. .
　本発明においてガスＸは、アセチレン骨格を少なくとも１つ有する炭化水素Ａと、１，３－ブタジエン骨格を少なくとも１つ有する炭化水素Ｂと、を含み、炭化水素Ａの合計体積濃度［Ａ］が０．１超過、炭化水素Ｂの合計体積濃度［Ｂ］が０．２８％以上とすることが肝要である。ガスＸ内に、炭化水素Ａ及び炭化水素Ｂを併存させ、かつ、体積濃度を上記のとおりとすることにより、ＣＮＴの品質を維持しつつ収量を上げることができる。
　なお、本明細書において、アセチレン骨格を少なくとも１つ有する炭化水素を「アセチレン類」と、１，３－ブタジエン骨格を少なくとも１つ有する炭化水素を「１，３－ブタジエン類」と、いう場合がある。 In the present invention, the gas X includes hydrocarbon A having at least one acetylene skeleton and hydrocarbon B having at least one 1,3-butadiene skeleton, and the total volume concentration [A] of the hydrocarbon A is 0. It is important that the total volume concentration [B] of hydrocarbon B exceeds 0.28%. By making hydrocarbon A and hydrocarbon B coexist in gas X and making the volume concentration as described above, the yield can be increased while maintaining the quality of CNT.
In the present specification, a hydrocarbon having at least one acetylene skeleton is referred to as “acetylenes”, and a hydrocarbon having at least one 1,3-butadiene skeleton is referred to as “1,3-butadienes”. is there.
　アセチレン骨格を少なくとも１つ有する炭化水素Ａとしては、例えば、アセチレン、メチルアセチレン（プロピン）、ビニルアセチレン、１－ブチン（エチルアセチレン）、２－ブチン、ジアセチレン、イソプロピルアセチレン、イソプロペニルアセチレン、１－ペンチン、２－ペンチン、イソペンチン、シクロプロペニルアセチレン、メチルビニルアセチレン、プロペニルアセチレン、フェニルアセチレン、ヘキシン類、及びヘキサジイン類、並びにそれらのラジカルからなる群から選択される少なくとも１種が挙げられる。ただし、ＣＮＴ成長温度における構造安定性の観点から、アセチレン、メチルアセチレン、ビニルアセチレン、２－ブチン、及びフェニルアセチレンが好ましい。 Examples of the hydrocarbon A having at least one acetylene skeleton include acetylene, methylacetylene (propyne), vinylacetylene, 1-butyne (ethylacetylene), 2-butyne, diacetylene, isopropylacetylene, isopropenylacetylene, 1- Examples thereof include at least one selected from the group consisting of pentyne, 2-pentyne, isopentine, cyclopropenylacetylene, methylvinylacetylene, propenylacetylene, phenylacetylene, hexynes, hexadiynes, and radicals thereof. However, acetylene, methylacetylene, vinylacetylene, 2-butyne, and phenylacetylene are preferred from the viewpoint of structural stability at the CNT growth temperature.
　１，３－ブタジエン骨格を少なくとも１つ有する炭化水素Ｂとしては、例えば、１，３－ブタジエン、イソプレン、ｃ－ピペリレン、及びｔ－ピペリレン、並びにそれらのラジカルからなる群から選択される少なくとも１種が挙げられる。ただし、ＣＮＴ製造効率の観点から、１，３－ブタジエンが好ましい。 Examples of the hydrocarbon B having at least one 1,3-butadiene skeleton include at least one selected from the group consisting of 1,3-butadiene, isoprene, c-piperylene, and t-piperylene, and radicals thereof. Is mentioned. However, 1,3-butadiene is preferred from the viewpoint of CNT production efficiency.
　本発明では、触媒に接触するガスＸ中の炭化水素Ａの合計体積濃度［Ａ］は０．１％超過である。ＣＮＴの品質を維持しつつ収量をより上げる効果として、［Ａ］は、より好ましくは０．３％以上、さらに好ましくは０．５％以上である。［Ａ］の上限濃度は炉内に設置する触媒の空間密度に比例する傾向があり、８８％まで上げることが可能である。触媒基材として平板を用いた場合、通常は１０％以下が好ましく、より好ましくは５％以下、さらに好ましくは２％以下である。触媒密度に対して炭化水素Ａの濃度が過剰であると、アモルファスカーボンなど炭素不純物の生成量が多くなり、用途によってはそれら不純物が無視できなくなってくる。 In the present invention, the total volume concentration [A] of the hydrocarbon A in the gas X in contact with the catalyst is more than 0.1%. As an effect of increasing the yield while maintaining the quality of CNT, [A] is more preferably 0.3% or more, and further preferably 0.5% or more. The upper limit concentration of [A] tends to be proportional to the spatial density of the catalyst installed in the furnace, and can be increased to 88%. When a flat plate is used as the catalyst base, it is usually preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less. If the concentration of hydrocarbon A is excessive with respect to the catalyst density, the amount of carbon impurities such as amorphous carbon produced increases, and these impurities cannot be ignored depending on the application.
　ガスＸ中の炭化水素Ｂの合計体積濃度［Ｂ］は０．２８％以上である。ＣＮＴの品質を維持しつつ収量をより上げる効果として、［Ｂ］は、より好ましくは０．５％以上、さらに好ましくは０．６％以上である。［Ｂ］の上限濃度は炉内に設置する触媒の空間密度に比例する傾向があり、９０％まで上げることが可能である。触媒基材として平板を用いた場合、通常は１０％以下が好ましく、より好ましくは５％以下、さらに好ましくは２％以下である。触媒密度に対して炭化水素Ｂの濃度が過剰であると、アモルファスカーボンなど炭素不純物の生成量が多くなり、用途によってはそれら不純物が無視できなくなってくる。 The total volume concentration [B] of hydrocarbon B in gas X is 0.28% or more. As an effect of increasing the yield while maintaining the quality of CNT, [B] is more preferably 0.5% or more, and even more preferably 0.6% or more. The upper limit concentration of [B] tends to be proportional to the spatial density of the catalyst installed in the furnace, and can be increased to 90%. When a flat plate is used as the catalyst base, it is usually preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less. If the concentration of hydrocarbon B is excessive with respect to the catalyst density, the amount of carbon impurities such as amorphous carbon produced increases, and these impurities cannot be ignored depending on the application.
　本発明の効果をより十分に得る観点から、［Ａ］／［Ｂ］は、０．１以上且つ８以下であることが好ましい。より好ましくは、０．２以上且つ６以下、さらに好ましくは、０．５以上且つ２以下である。 [A] / [B] is preferably 0.1 or more and 8 or less from the viewpoint of obtaining the effect of the present invention more sufficiently. More preferably, they are 0.2 or more and 6 or less, More preferably, they are 0.5 or more and 2 or less.
　ガスＸは、シクロペンタジエン骨格を少なくとも１つ有する炭化水素Ｃをさらに含むことが好ましい。該炭化水素Ｃとしては、例えば、シクロペンタジエン、インデン、メチルシクロペンタジエン、ジメチルシクロペンタジエン、トリメチルシクロペンタジエン、テトラメチルシクロペンタジエン、ペンタメチルシクロペンタジエン、及びエチルシクロペンタジエン、並びにそれらのラジカルからなる群から選択される少なくとも１種が挙げられる。ただし、ＣＮＴ成長温度における構造安定性の観点から、シクロペンタジエン及びメチルシクロペンタジエンが好ましい。ガスＸが炭化水素Ｃを含むことによって、ＣＮＴの収量および品質を維持しつつ、必要な炭化水素Ａを低減することが可能になる。アセチレン類は化学反応性が高いため、他のガスと比較して取扱や安全性に課題があり運用コストが増加する傾向がある。それゆえ、炭化水素Ａの使用量を可能な限り低減することが好ましい。 The gas X preferably further contains a hydrocarbon C having at least one cyclopentadiene skeleton. The hydrocarbon C is, for example, selected from the group consisting of cyclopentadiene, indene, methylcyclopentadiene, dimethylcyclopentadiene, trimethylcyclopentadiene, tetramethylcyclopentadiene, pentamethylcyclopentadiene, and ethylcyclopentadiene, and radicals thereof. And at least one of them. However, cyclopentadiene and methylcyclopentadiene are preferred from the viewpoint of structural stability at the CNT growth temperature. By including the hydrocarbon C in the gas X, it is possible to reduce the required hydrocarbon A while maintaining the yield and quality of CNT. Since acetylenes have high chemical reactivity, there is a problem in handling and safety compared to other gases, and there is a tendency that operation costs increase. Therefore, it is preferable to reduce the amount of hydrocarbon A used as much as possible.
　ガスＸ中の炭化水素Ｃの合計体積濃度［Ｃ］は、上記効果を十分に得る観点から、０．０６％以上であることが好ましく、より好ましくは、０．２％以上、さらに好ましくは、０．３％以上である。また、ガスＸ中の炭化水素Ｃの合計体積濃度［Ｃ］は、炉内に設置する触媒の空間密度に比例する傾向があり、９９％まで上げることが可能である。アモルファスカーボンなど炭素不純物の生成を抑える観点から、触媒基材として平板を用いた場合、通常は１０％以下が好ましく、より好ましくは、５％以下、さらに好ましくは、２％以下である。
　なお、本明細書において、シクロペンタジエン骨格を少なくとも１つ有する炭化水素を「シクロペンタジエン類」という場合がある。 The total volume concentration [C] of hydrocarbon C in gas X is preferably 0.06% or more, more preferably 0.2% or more, and still more preferably, from the viewpoint of sufficiently obtaining the above effect. It is 0.3% or more. Further, the total volume concentration [C] of the hydrocarbons C in the gas X tends to be proportional to the spatial density of the catalyst installed in the furnace, and can be increased to 99%. From the viewpoint of suppressing the generation of carbon impurities such as amorphous carbon, when a flat plate is used as the catalyst substrate, it is usually preferably 10% or less, more preferably 5% or less, and further preferably 2% or less.
In the present specification, a hydrocarbon having at least one cyclopentadiene skeleton may be referred to as “cyclopentadiene”.
　なお、本発明において、接触ガスの同定及び体積濃度の測定は、基材設置位置近傍のガスを所定量吸引サンプリングして、ガスクロマトグラフィー（ＧＣ）によりガス分析することで行うものとする。サンプリングにおいて、ガスは熱分解が進行しない温度（約２００℃）まで短時間に急冷された後に、直ちにＧＣへ導入される。これによって、サンプルガスの化学変化を防止し、触媒に接触しているガスの組成を正しく測定することが可能になる。 In the present invention, the identification of the contact gas and the measurement of the volume concentration are performed by sucking and sampling a predetermined amount of gas in the vicinity of the substrate installation position and performing gas analysis by gas chromatography (GC). In sampling, the gas is rapidly cooled to a temperature at which pyrolysis does not proceed (about 200 ° C.) in a short time, and then immediately introduced into the GC. This prevents chemical changes in the sample gas and makes it possible to correctly measure the composition of the gas in contact with the catalyst.
　＜原料ガス＞
　ガスＸを上記のようにするために、原料ガスは、アセチレン骨格を少なくとも１つ有する炭化水素Ａ’と、１，３－ブタジエン骨格を少なくとも１つ有する炭化水素Ｂ’と、を含むことが好ましい。 <Raw gas>
In order to make the gas X as described above, the source gas preferably contains a hydrocarbon A ′ having at least one acetylene skeleton and a hydrocarbon B ′ having at least one 1,3-butadiene skeleton. .
　炭化水素Ａ’は、アセチレン、メチルアセチレン、ビニルアセチレン、１－ブチン、２－ブチン、イソプロピルアセチレン及びイソプロペニルアセチレンからなる群から選択される少なくとも１種とすることが好ましい。原料ガス中、炭化水素Ａ’の合計体積濃度［Ａ’］は、０．１％以上であることが好ましく、より好ましくは、０．２％以上、さらに好ましくは０．３％以上である。また、［Ａ’］は８６％まで上げることが可能であり、通常は１０％以下であることが好ましく、より好ましくは、５％以下、さらに好ましくは、２％以下である。炭化水素Ａ’の濃度が低すぎると本発明の効果が得にくく、高すぎるとアモルファスカーボン等の炭素不純物が生成し、用途によってはそれら不純物が無視できなくなる傾向がある。 The hydrocarbon A ′ is preferably at least one selected from the group consisting of acetylene, methylacetylene, vinylacetylene, 1-butyne, 2-butyne, isopropylacetylene and isopropenylacetylene. The total volume concentration [A ′] of the hydrocarbon A ′ in the raw material gas is preferably 0.1% or more, more preferably 0.2% or more, and further preferably 0.3% or more. [A '] can be increased to 86%, and is usually preferably 10% or less, more preferably 5% or less, and still more preferably 2% or less. If the concentration of the hydrocarbon A ′ is too low, it is difficult to obtain the effect of the present invention. If the concentration is too high, carbon impurities such as amorphous carbon are generated, and depending on the application, these impurities tend not to be negligible.
　炭化水素Ｂ’は、１，３－ブタジエン、イソプレン、ｃ－ピペリレン、及びｔ－ピペリレンからなる群から選択される少なくとも１種とすることが好ましい。原料ガス中、炭化水素Ｂ’の合計体積濃度［Ｂ’］は、０．３％以上であることが好ましく、より好ましくは、０．４％以上、さらに好ましくは、０．５％以上である。また、［Ｂ’］は９０％まで上げることが可能であり、通常は１０％以下であることが好ましく、より好ましくは５％以下、さらに好ましくは２％以下である。炭化水素Ｂ’の濃度が低すぎると本発明の効果が得にくく、高すぎるとアモルファスカーボン等の炭素不純物が生成し、用途によってはそれら不純物が無視できなくなる傾向がある。 The hydrocarbon B ′ is preferably at least one selected from the group consisting of 1,3-butadiene, isoprene, c-piperylene, and t-piperylene. In the raw material gas, the total volume concentration [B ′] of hydrocarbon B ′ is preferably 0.3% or more, more preferably 0.4% or more, and further preferably 0.5% or more. . [B ′] can be increased to 90%, and is usually preferably 10% or less, more preferably 5% or less, and further preferably 2% or less. If the concentration of the hydrocarbon B ′ is too low, it is difficult to obtain the effect of the present invention. If the concentration is too high, carbon impurities such as amorphous carbon are generated, and depending on the use, these impurities cannot be ignored.
　また、［Ａ’］／［Ｂ’］は、０．１以上且つ６以下であることが好ましい。より好ましくは、０．２以上且つ３以下、さらに好ましくは、０．３以上且つ２以下である。この範囲内とすることにより、ガスＸをより確実に本発明の範囲に設定することができる。 [A ′] / [B ′] is preferably 0.1 or more and 6 or less. More preferably, they are 0.2 or more and 3 or less, More preferably, they are 0.3 or more and 2 or less. By setting it within this range, the gas X can be more reliably set within the range of the present invention.
　さらに、原料ガスは、炭素数５の炭素環を少なくとも１つ有する炭化水素Ｃ’を含むことが好ましい。 Furthermore, the source gas preferably contains hydrocarbon C ′ having at least one carbon ring having 5 carbon atoms.
　炭化水素Ｃ’は、シクロペンタジエン、ジシクロペンタジエン、シクロペンテン、ノルボルネン、ノルボルナジエン及びシクロペンタンからなる群から選択される少なくとも１種とすることが好ましい。上記効果を十分に得る観点から、原料ガス中、炭化水素Ｃ’の合計体積濃度［Ｃ’］は０．１％以上であることが好ましく、より好ましくは、０．２％以上、さらに好ましくは０．３％以上である。炭化水素Ｃ’の濃度が低すぎると本発明の効果が得にくく、高すぎるとアモルファスカーボンなど炭素不純物が生成し、用途によってはそれら不純物が無視できなくなる傾向がある。また、原料ガス中、炭化水素Ｃ’の合計体積濃度［Ｃ’］は、炉内に設置する触媒の空間密度に比例する傾向があり、９９％まで上げることが可能である。アモルファスカーボンなど炭素不純物の生成を抑える観点から、触媒基材として平板を用いた場合、通常は１０％以下が好ましく、より好ましくは、５％以下、さらに好ましくは、２％以下である。 The hydrocarbon C ′ is preferably at least one selected from the group consisting of cyclopentadiene, dicyclopentadiene, cyclopentene, norbornene, norbornadiene, and cyclopentane. From the viewpoint of sufficiently obtaining the above effect, the total volume concentration [C ′] of hydrocarbon C ′ in the raw material gas is preferably 0.1% or more, more preferably 0.2% or more, and still more preferably. It is 0.3% or more. If the concentration of the hydrocarbon C ′ is too low, it is difficult to obtain the effects of the present invention. If the concentration is too high, carbon impurities such as amorphous carbon are generated, and these impurities tend not to be negligible depending on the application. Further, the total volume concentration [C ′] of hydrocarbons C ′ in the raw material gas tends to be proportional to the spatial density of the catalyst installed in the furnace, and can be increased to 99%. From the viewpoint of suppressing the generation of carbon impurities such as amorphous carbon, when a flat plate is used as the catalyst substrate, it is usually preferably 10% or less, more preferably 5% or less, and further preferably 2% or less.
　＜不活性ガス＞
　原料ガスは、通常、不活性ガスで希釈されることになる。不活性ガスとしては、ＣＮＴが成長する温度で不活性であり、且つ成長するＣＮＴと反応しないガスであればよく、触媒の活性を低下させないものが好ましい。例えば、ヘリウム、アルゴン、ネオン、及びクリプトン等の希ガス、窒素、水素、並びにこれらの混合ガスを例示できる。
　また、不活性ガスを用いずに、炉内全体を減圧し、各種ガス濃度の分圧を減らすことで、不活性ガス希釈と同等の効果を得ることも可能である。 <Inert gas>
The source gas is usually diluted with an inert gas. The inert gas may be any gas that is inert at the temperature at which the CNT grows and does not react with the growing CNT, and preferably does not reduce the activity of the catalyst. For example, noble gases such as helium, argon, neon, and krypton, nitrogen, hydrogen, and mixed gas thereof can be exemplified.
Moreover, it is also possible to obtain the same effect as dilution of an inert gas by reducing the pressure inside the furnace and reducing the partial pressure of various gas concentrations without using an inert gas.
　＜触媒賦活物質＞
　ＣＮＴの成長工程において、触媒賦活物質を添加してもよい。触媒賦活物質の添加によって、ＣＮＴの生産効率や純度をより一層改善することができる。ここで用いる触媒賦活物質としては、一般には酸素を含む物質であり、成長温度でＣＮＴに多大なダメージを与えない物質であることが好ましい。例えば、水、酸素、オゾン、酸性ガス、酸化窒素、一酸化炭素、及び二酸化炭素等の低炭素数の含酸素化合物；エタノール、メタノール等のアルコール類；テトラヒドロフラン等のエーテル類；アセトン等のケトン類；アルデヒド類；エステル類；並びにこれらの混合物が有効である。この中でも、水、酸素、一酸化炭素、二酸化炭素、及びエーテル類が好ましく、特に水、一酸化炭素、二酸化炭素、並びにこれらの混合物が好適である。 <Catalyst activation material>
In the CNT growth process, a catalyst activator may be added. By adding a catalyst activator, the production efficiency and purity of CNTs can be further improved. The catalyst activator used here is generally a substance containing oxygen, and is preferably a substance that does not significantly damage the CNT at the growth temperature. For example, low carbon number oxygen-containing compounds such as water, oxygen, ozone, acidic gas, nitrogen oxide, carbon monoxide, and carbon dioxide; alcohols such as ethanol and methanol; ethers such as tetrahydrofuran; ketones such as acetone Aldehydes; esters; as well as mixtures thereof are useful. Among these, water, oxygen, carbon monoxide, carbon dioxide, and ethers are preferable, and water, carbon monoxide, carbon dioxide, and a mixture thereof are particularly preferable.
　触媒賦活物質の体積濃度は、特に限定されないが微量でよく、例えば水の場合、炉内に導入される原料ガス中、その含有量は、通常、０．００１％以上且つ１％以下、好ましくは０．００５％以上且つ０．１％以下とする。この場合、ガスＸにおいては、通常、０．００１％以上且つ１％以下、好ましくは０．００５％以上且つ０．１％以下となる。触媒賦活物質が二酸化炭素の場合、炉内に導入される原料ガス中、その含有量は、通常、０．５％以上且つ２０％以下、好ましくは２％以上且つ８％以下とする。この場合、ガスＸにおいては、通常、０．５％以上且つ２０％以下、好ましくは２％以上且つ８％以下となる。 The volume concentration of the catalyst activator is not particularly limited, but may be a very small amount. For example, in the case of water, the content is usually 0.001% or more and 1% or less, preferably in the raw material gas introduced into the furnace. 0.005% or more and 0.1% or less. In this case, the gas X is usually 0.001% or more and 1% or less, preferably 0.005% or more and 0.1% or less. When the catalyst activation material is carbon dioxide, the content of the raw material gas introduced into the furnace is usually 0.5% or more and 20% or less, preferably 2% or more and 8% or less. In this case, the gas X is usually 0.5% or more and 20% or less, preferably 2% or more and 8% or less.
　本発明においてガスＸとしては、本発明の効果をより充分に得る観点から、触媒賦活物質及び／又は還元ガスとして水素分子からなる水素ガスをさらに含むことが好ましい。 In the present invention, the gas X preferably further contains a hydrogen gas composed of hydrogen molecules as a catalyst activator and / or a reducing gas from the viewpoint of obtaining the effects of the present invention more sufficiently.
　なお、一般的にＣＶＤ法における反応速度に影響を与えるのは、反応に関与する成分の分圧（体積分率×全圧）であることが知られている。一方、全圧は直接に影響を与えないので、広い範囲で変更することが可能である。よって、ＣＶＤ条件においてガス成分濃度を規定する単位としては分圧を用いることが正確であるが、本発明においては、原料ガス及び接触ガスのガス成分濃度を、成長炉内全圧が１気圧の前提の下での体積分率で記述することとする。よって、成長炉内全圧が１気圧以外の場合に本発明を適用する際は、原料ガス及び接触ガスのガス成分濃度として、その環境下、前記前提の下での分圧に等しい分圧を示しうるように修正した体積分率を用いなければならない。成長炉内全圧が１気圧以外の場合におけるそのような修正は当業者にとって明らかであり、従って、かかる場合も本発明の範囲に包含される。 Note that it is generally known that the partial pressure (volume fraction × total pressure) of the components involved in the reaction affects the reaction rate in the CVD method. On the other hand, since the total pressure does not directly affect, it can be changed in a wide range. Therefore, it is accurate to use the partial pressure as a unit for defining the gas component concentration in the CVD condition. However, in the present invention, the gas component concentration of the source gas and the contact gas is set to the total pressure in the growth reactor of 1 atm. Describe the volume fraction under the assumption. Therefore, when the present invention is applied when the total pressure in the growth furnace is other than 1 atm, the partial pressure equal to the partial pressure under the above-mentioned assumption is used as the gas component concentration of the source gas and the contact gas in the environment. A corrected volume fraction should be used as shown. Such modifications will be apparent to those skilled in the art when the total pressure in the growth reactor is other than 1 atm. Therefore, such cases are also included in the scope of the present invention.
　＜その他の条件＞
　成長工程における反応炉内の圧力、処理時間は、他の条件を考慮して適宜設定すればよいが、例えば、圧力は１０２Ｐａ以上且つ１０７Ｐａ以下、処理時間は０．１分以上且つ１２０分以下程度とすることができる。炉内に導入される原料ガスの流量については、例えば、後述する実施例を参照して適宜設定することができる。 <Other conditions>
The pressure in the reactor and the treatment time in the growth step may be appropriately set in consideration of other conditions. For example, the pressure is 10 2 Pa or more and 10 7 Pa or less, the treatment time is 0.1 minutes or more and It can be about 120 minutes or less. About the flow volume of the raw material gas introduce | transduced in a furnace, it can set suitably with reference to the Example mentioned later, for example.
　（冷却工程）
　冷却工程とは、成長工程後にＣＮＴ配向集合体、触媒、基材を冷却ガス下に冷却する工程である。成長工程後のＣＮＴ配向集合体、触媒、基材は高温状態にあるため、酸素存在環境下に置かれると酸化してしまうおそれがある。それを防ぐために冷却ガス環境下でＣＮＴ配向集合体、触媒、基材を例えば４００℃以下、更に好ましくは２００℃以下に冷却する。冷却ガスとしては不活性ガスが好ましく、特に安全性、コスト等の点から窒素であることが好ましい。 (Cooling process)
The cooling step is a step of cooling the aligned CNT aggregate, the catalyst, and the base material under a cooling gas after the growth step. Since the aligned CNT aggregate, the catalyst, and the substrate after the growth step are in a high temperature state, they may be oxidized when placed in an oxygen-existing environment. In order to prevent this, the aligned CNT aggregate, the catalyst, and the substrate are cooled to, for example, 400 ° C. or lower, more preferably 200 ° C. or lower, in a cooling gas environment. As the cooling gas, an inert gas is preferable, and nitrogen is particularly preferable from the viewpoints of safety and cost.
　（製造装置）
　本発明の実施に用いる製造装置は、触媒基材を受容する成長炉（反応チャンバ）を備え、ＣＶＤ法によりＣＮＴを成長させることができるものであれば、特に限定されず、熱ＣＶＤ炉、ＭＯＣＶＤ反応炉等の装置を使用できる。ＣＮＴの製造効率を高める観点からは、還元ガス及び原料ガスをガスシャワーによって触媒基材上の触媒に供給することが好ましく、以下、触媒基材に対し概ね直交するようにガス流を噴出可能なシャワーヘッドを備えた装置の例も挙げて説明する。 (Manufacturing equipment)
The manufacturing apparatus used for carrying out the present invention is not particularly limited as long as it has a growth furnace (reaction chamber) for receiving a catalyst base material and can grow CNTs by a CVD method. Equipment such as a reactor can be used. From the viewpoint of increasing the production efficiency of CNTs, it is preferable to supply the reducing gas and the raw material gas to the catalyst on the catalyst base by a gas shower. Hereinafter, a gas flow can be ejected so as to be substantially orthogonal to the catalyst base. An example of an apparatus provided with a shower head will also be described.
　＜バッチ式製造装置の一例＞
　本発明に適用されるＣＮＴ製造装置１００を図１に模式的に示す。この装置１００は、石英からなる反応炉１０２と、反応炉１０２を外囲するように設けられた例えば抵抗発熱コイル等からなる加熱器１０４と、還元ガス及び原料ガスを供給すべく反応炉１０２の一端に接続されたガス供給口１０６と、反応炉１０２の他端に接続された排気口１０８と、基材を固定する石英からなるホルダー１１０とを含んで構成される。さらに図示していないが、還元ガス及び原料ガスの流量を制御するため、流量制御弁及び圧力制御弁等を含む制御装置を適所に付設してなる。 <Example of batch production equipment>
A CNT manufacturing apparatus 100 applied to the present invention is schematically shown in FIG. The apparatus 100 includes a reaction furnace 102 made of quartz, a heater 104 made of, for example, a resistance heating coil provided so as to surround the reaction furnace 102, and a reaction furnace 102 for supplying a reducing gas and a source gas. It includes a gas supply port 106 connected to one end, an exhaust port 108 connected to the other end of the reaction furnace 102, and a holder 110 made of quartz for fixing the substrate. Although not shown, a control device including a flow rate control valve, a pressure control valve, and the like is provided at an appropriate place in order to control the flow rates of the reducing gas and the raw material gas.
　＜バッチ式製造装置の他の例＞
　本発明に適用されるＣＮＴ製造装置２００を図２に模式的に示す。この装置２００は、還元ガス、原料ガス、触媒賦活物質等を噴射するシャワーヘッド１１２を用いる以外は、図１に示す装置と同じ構成である。 <Other examples of batch manufacturing equipment>
A CNT manufacturing apparatus 200 applied to the present invention is schematically shown in FIG. The apparatus 200 has the same configuration as the apparatus shown in FIG. 1 except that a shower head 112 that injects a reducing gas, a raw material gas, a catalyst activation material, and the like is used.
　シャワーヘッド１１２は、各噴出孔の噴射軸線が基材の触媒被膜形成面に概ね直交する向きとなるように配置される。つまりシャワーヘッドに設けられた噴出孔から噴出するガス流の方向が、基材に概ね直交する。 The shower head 112 is disposed so that the spray axis of each spray hole is in a direction substantially perpendicular to the catalyst coating surface of the base material. That is, the direction of the gas flow ejected from the ejection holes provided in the shower head is substantially orthogonal to the base material.
　シャワーヘッド１１２を用いて還元ガスを噴射すると、還元ガスを基材上に均一に散布することができ、効率良く触媒を還元することができる。結果、基材上に成長するＣＮＴ配向集合体の均一性を高めることができ、且つ還元ガスの消費量を削減することもできる。このようなシャワーヘッドを用いて原料ガスを噴射すると、原料ガスを基材上に均一に散布することができ、効率良く原料ガスを消費することができる。結果、基材上に成長するＣＮＴ配向集合体の均一性を高めることができ、且つ原料ガスの消費量を削減することもできる。このようなシャワーヘッドを用いて触媒賦活物質を噴射すると、触媒賦活物質を基板上に均一に散布することができ、触媒の活性が高まると共に寿命が延長するので、配向ＣＮＴの成長を長時間継続させることが可能となる。 When the reducing gas is injected using the shower head 112, the reducing gas can be uniformly sprayed on the substrate, and the catalyst can be reduced efficiently. As a result, the uniformity of the aligned CNT aggregates grown on the substrate can be improved, and the consumption of reducing gas can also be reduced. When the raw material gas is injected using such a shower head, the raw material gas can be uniformly sprayed on the substrate, and the raw material 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. When a catalyst activation material is injected using such a showerhead, the catalyst activation material can be uniformly sprayed on the substrate, and the activity of the catalyst is increased and the lifetime is extended. It becomes possible to make it.
　＜連続製造装置の一例＞
　本発明に適用されるＣＮＴ製造装置３００を図３に模式的に示す。
　図３に示すように、製造装置３００は、入口パージ部１、フォーメーションユニット２、成長ユニット３、冷却ユニット４、出口パージ部５、搬送ユニット６、接続部７、８、９、及びガス混入防止手段１１、１２、１３を有する。 <Example of continuous production equipment>
A CNT production apparatus 300 applied to the present invention is schematically shown in FIG.
As shown in FIG. 3, the manufacturing apparatus 300 includes an inlet purge unit 1, a formation unit 2, a growth unit 3, a cooling unit 4, an outlet purge unit 5, a transport unit 6, connection units 7, 8, 9, and gas mixture prevention. Means 11, 12, and 13 are included.
　〔入口パージ部１〕
　入口パージ部１は、触媒基材１０の入口から炉内へ外気が混入することを防止するための装置一式である。製造装置３００内に搬送された触媒基材１０の周囲環境を窒素等の不活性パージガスで置換する機能を有する。具体的には、パージガスを保持するためのチャンバ、パージガスを噴射するための噴射部等を有する。 [Inlet purge section 1]
The inlet purge unit 1 is a set of devices for preventing outside air from entering the furnace from the inlet of the catalyst base 10. It has a function of replacing the surrounding environment of the catalyst substrate 10 conveyed into the manufacturing apparatus 300 with an inert purge gas such as nitrogen. Specifically, a chamber for holding the purge gas, an injection unit for injecting the purge gas, and the like are included.
　〔フォーメーションユニット２〕
　フォーメーションユニット２は、フォーメーション工程を実現するための装置一式である。具体的には、還元ガスを保持するためのフォーメーション炉２Ａ、還元ガスを噴射するための還元ガス噴射部２Ｂ、並びに触媒及び還元ガスの少なくとも一方を加熱するためのヒーター２Ｃなどを有する。 [Formation unit 2]
The formation unit 2 is a set of devices for realizing the formation process. Specifically, it includes a formation furnace 2A for holding the reducing gas, a reducing gas injection unit 2B for injecting the reducing gas, and a heater 2C for heating at least one of the catalyst and the reducing gas.
　〔成長ユニット３〕
　成長ユニット３は、成長工程を実現するための装置一式である。具体的には、成長炉３Ａ、原料ガスを触媒基材１０上に噴射するための原料ガス噴射部３Ｂ、並びに触媒及び原料ガスの少なくとも一方を加熱するためのヒーター３Ｃを含んでいる。成長ユニット３の上部には排気口３Ｄが設けられている。 [Growth unit 3]
The growth unit 3 is a set of apparatuses for realizing a growth process. Specifically, a growth furnace 3A, a raw material gas injection unit 3B for injecting a raw material gas onto the catalyst base 10, and a heater 3C for heating at least one of the catalyst and the raw material gas are included. An exhaust port 3 </ b> D is provided in the upper part of the growth unit 3.
　〔冷却ユニット４〕
　冷却ユニット４は、ＣＮＴ配向集合体が成長した触媒基材１０を冷却する冷却工程を実現する装置一式である。具体的には、冷却ガスを保持するための冷却炉４Ａ、水冷式の場合は冷却炉内空間を囲むように配置した水冷冷却管４Ｃ、空冷式の場合は冷却炉内に冷却ガスを噴射する冷却ガス噴射部４Ｂを有する。 [Cooling unit 4]
The cooling unit 4 is a set of devices that realizes a cooling process for cooling the catalyst base 10 on which the aligned CNT aggregate has grown. Specifically, the cooling furnace 4A for holding the cooling gas, in the case of the water-cooled type, the water-cooled cooling pipe 4C disposed so as to surround the space in the cooling furnace, and in the case of the air-cooled type, the cooling gas is injected into the cooling furnace. It has the cooling gas injection part 4B.
　〔出口パージ部５〕
　出口パージ部５は、触媒基材１０の出口から炉内へ外気が混入することを防止するための装置一式である。触媒基材１０の周囲環境を窒素等の不活性パージガス環境にする機能を有する。具体的には、パージガスを保持するためのチャンバ、パージガスを噴射するための噴射部等を有する。 [Outlet purge section 5]
The outlet purge unit 5 is a set of devices for preventing outside air from being mixed into the furnace from the outlet of the catalyst base 10. It has a function to make the surrounding environment of the catalyst substrate 10 an inert purge gas environment such as nitrogen. Specifically, a chamber for holding the purge gas, an injection unit for injecting the purge gas, and the like are included.
　〔搬送ユニット６〕
　搬送ユニット６は、製造装置の炉内に触媒基材１０を搬送するための装置一式である。具体的には、ベルトコンベア方式におけるメッシュベルト６Ａ、減速機付き電動モータを用いたベルト駆動部６Ｂ等を有する。 [Transport unit 6]
The transport unit 6 is a set of apparatuses for transporting the catalyst base 10 into the furnace of the manufacturing apparatus. Specifically, a mesh belt 6A in a belt conveyor system, a belt driving unit 6B using an electric motor with a reduction gear, and the like are included.
　〔接続部７、８、９〕
　接続部７、８、９は、各ユニットの炉内空間を空間的に接続する装置一式である。具体的には、触媒基材１０の周囲環境と外気を遮断し、触媒基材１０をユニットからユニットへ通過させることができる炉又はチャンバ等が挙げられる。 [ Connections 7, 8, 9]
The connection portions 7, 8, and 9 are a set of devices that spatially connect the furnace space of each unit. Specifically, a furnace or a chamber that can block the ambient environment of the catalyst base 10 and the outside air and allow the catalyst base 10 to pass from unit to unit can be used.
　〔ガス混入防止手段１１、１２、１３〕
　ガス混入防止手段１１、１２、１３は、製造装置３００内の隣接する炉（フォーメーション炉２Ａ、成長炉３Ａ、冷却炉４Ａ）間でガス同士が相互に混入することを防止するための装置一式であり、接続部７、８、９に設置される。ガス混入防止手段１１、１２、１３は、各炉における触媒基材１０の入口及び出口の開口面に沿って窒素等のシールガスを噴出するシールガス噴射部１１Ｂ、１２Ｂ、１３Ｂと、主に噴射されたシールガスを外部に排気する排気部１１Ａ、１２Ａ、１３Ａとを、それぞれ有する。 [Gas mixing prevention means 11, 12, 13]
The gas mixing prevention means 11, 12, 13 are a set of devices for preventing gas from being mixed with each other between adjacent furnaces (formation furnace 2 </ b> A, growth furnace 3 </ b> A, cooling furnace 4 </ b> A) in the manufacturing apparatus 300. Yes, installed in the connecting parts 7, 8, 9. The gas mixing preventing means 11, 12, 13 are mainly injected with seal gas injection portions 11B, 12B, 13B for injecting a seal gas such as nitrogen along the opening surfaces of the inlet and outlet of the catalyst base 10 in each furnace. Exhaust portions 11A, 12A and 13A for exhausting the sealed gas to the outside are provided.
　メッシュベルト６Ａに載置された触媒基材１０は装置入口から入口パージ部１の炉内へと搬送され、以降、各炉内で処理を受けた後、出口パージ部５から装置出口を介して装置外部に搬送される。 The catalyst base 10 placed on the mesh belt 6A is transported from the apparatus inlet to the furnace of the inlet purge unit 1, and after being treated in each furnace, from the outlet purge unit 5 through the apparatus outlet. It is transported outside the device.
　（炭素ナノ構造体）
　本発明の製造方法によれば、上述のようにして高品質なＣＮＴを高効率に製造可能であるが、ＣＮＴに限られず、公知文献を参照して適宜製造条件を設定することにより、カーボンナノコイル等その他、ＣＶＤ法により触媒表面上に成長させることが可能な、ｓｐ２混成軌道からなる炭素を含む、種々の炭素ナノ構造体を製造することができる。前記公知文献としては、例えば、特開２００９－１２７０５９号公報（ダイヤモンドライクカーボン）、特開２０１３－８６９９３号公報（グラフェン）、特開２００１－１９２２０４号公報（コイル・ツイスト）、及び特開２００３－２７７０２９号公報（フラーレン）等が挙げられる。 (Carbon nanostructure)
According to the production method of the present invention, high-quality CNTs can be produced with high efficiency as described above. However, the production method is not limited to CNTs. In addition, various carbon nanostructures including a coil composed of sp2 hybrid orbits that can be grown on the catalyst surface by a CVD method, such as a coil, can be produced. Examples of the known literature include, for example, Japanese Unexamined Patent Application Publication No. 2009-127059 (diamond-like carbon), Japanese Unexamined Patent Application Publication No. 2013-86993 (graphene), Japanese Unexamined Patent Application Publication No. 2001-192204 (coil twist), and Japanese Unexamined Patent Application Publication No. 2003-2003. No. 277029 (fullerene).
　以下、本発明の製造方法により得られる炭素ナノ構造体の一例として、本発明の製造方法により得られるＣＮＴについて説明する。なお、ＣＮＴは、本発明の製造方法により直接的にはＣＮＴ配向集合体として得られる。当該集合体を、例えば、物理的、化学的又は機械的な剥離方法、具体的には、電場、磁場、遠心力又は表面張力を用いて剥離する方法や、ピンセットやカッターブレードを用いて機械的に直接剥ぎ取る方法や、真空ポンプによる吸引等の圧力や熱により剥離する方法等により、触媒基材から剥離することで、バルク状態のＣＮＴや、粉体状態のＣＮＴを得ることができる。 Hereinafter, CNT obtained by the production method of the present invention will be described as an example of the carbon nanostructure obtained by the production method of the present invention. CNTs are directly obtained as aligned CNT aggregates by the production method of the present invention. For example, a physical, chemical or mechanical peeling method, specifically, a method of peeling using an electric field, a magnetic field, centrifugal force or surface tension, or mechanical using tweezers or a cutter blade. The CNT in the bulk state or the CNT in the powder state can be obtained by peeling off from the catalyst substrate by a method of peeling directly onto the catalyst substrate or a method of peeling off by pressure or heat such as suction by a vacuum pump.
　本発明の製造方法によるＣＮＴの収量は、２．４ｍｇ／ｃｍ２以上であることが好ましく、２．８ｍｇ／ｃｍ２以上であることが更に好ましい。なお、本発明において収量は以下の式により算出するものとする。
　　（収量）＝（ＣＮＴ製造前後での基材重量差）／（基材の触媒担持面積） The yield of CNTs by the production method of the present invention is preferably 2.4 mg / cm 2 or more, and more preferably 2.8 mg / cm 2 or more. In the present invention, the yield is calculated by the following formula.
(Yield) = (Substrate weight difference before and after CNT production) / (Catalyst carrying area of substrate)
　本発明の製造方法において、炭素変換効率は、１．６％以上であることが好ましく、２．８％以上であることが更に好ましい。なお、本発明において「炭素変換効率」とは、（製造されたＣＮＴ重量）／（炉内に導入した全炭素重量）×１００［％］を意味し、「炉内に導入した全炭素重量」は、理想気体近似の仮定のもと、ガス流量、原料ガスの炭素濃度及び成長時間の、以上３つの値から算出することができる。 In the production method of the present invention, the carbon conversion efficiency is preferably 1.6% or more, and more preferably 2.8% or more. In the present invention, “carbon conversion efficiency” means (weight of manufactured CNT) / (total carbon weight introduced into the furnace) × 100 [%], and “total carbon weight introduced into the furnace” Can be calculated from the above three values of the gas flow rate, the carbon concentration of the source gas, and the growth time under the assumption of an ideal gas approximation.
　なお、本発明において炭素濃度は、ガスに含まれる炭素原子濃度を示し、ガス中の各炭化水素ガス種（ｉ＝１、２、・・・）に対して、濃度（ｖｏｌ％）をＤ１、Ｄ２、・・・、分子１つに含まれる炭素原子数をＣ１、Ｃ２、・・・として下記数式で計算している。
　　（炭素濃度）＝ΣＤｉＣｉ In the present invention, the carbon concentration indicates the concentration of carbon atoms contained in the gas, and the concentration (vol%) is D1, for each hydrocarbon gas species (i = 1, 2,...) In the gas. D2,..., The number of carbon atoms contained in one molecule is calculated as C1, C2,.
(Carbon concentration) = ΣDiCi
　原料ガス中の炭素濃度は、本発明の効果をより十分に得る観点から、好ましくは１．３％以上、より好ましくは２．０％以上、更に好ましくは３．０％以上とする。炭素濃度の上限は炉内の触媒密度に比例する傾向があり、３８０％まで上げることが可能である。触媒基材として平板を用いた場合、炭素濃度は、通常は６０％以下が好ましく、更に好ましくは３０％以下、特に好ましくは２０％以下である。触媒密度の量に対して炭素濃度が過剰であるとアモルファスカーボンなど炭素不純物が生成し、用途によってはそれら不純物が無視できなくなってくる。 The carbon concentration in the raw material gas is preferably 1.3% or more, more preferably 2.0% or more, and further preferably 3.0% or more from the viewpoint of obtaining the effects of the present invention more sufficiently. The upper limit of the carbon concentration tends to be proportional to the catalyst density in the furnace and can be increased to 380%. When a flat plate is used as the catalyst substrate, the carbon concentration is usually preferably 60% or less, more preferably 30% or less, and particularly preferably 20% or less. If the carbon concentration is excessive with respect to the amount of catalyst density, carbon impurities such as amorphous carbon are generated, and these impurities cannot be ignored depending on the application.
　ＣＮＴは、単層カーボンナノチューブであっても良いし、多層カーボンナノチューブであってもよいが、本発明の製造方法によれば単層カーボンナノチューブをより好適に製造することができる。 CNTs may be single-walled carbon nanotubes or multi-walled carbon nanotubes, but according to the production method of the present invention, single-walled carbon nanotubes can be more suitably produced.
　ＣＮＴの平均直径（Ａｖ）としては、０．５ｎｍ以上であることが好ましく、１ｎｍ以上であることが更に好ましく、１５ｎｍ以下であることが好ましく、１０ｎｍ以下であることが更に好ましい。カーボンナノチューブの平均直径（Ａｖ）は、通常、透過型電子顕微鏡を用いてカーボンナノチューブを１００本測定して求める。 The average diameter (Av) of CNTs is preferably 0.5 nm or more, more preferably 1 nm or more, preferably 15 nm or less, and more preferably 10 nm or less. The average diameter (Av) of the carbon nanotubes is usually determined by measuring 100 carbon nanotubes using a transmission electron microscope.
　ＣＮＴは、本発明の製造方法によりＣＮＴ配向集合体として得られるが、その比表面積は、６００ｍ２／ｇ以上であることが好ましく、８００ｍ２／ｇ以上であることが更に好ましく、２５００ｍ２／ｇ以下であることが好ましく、１４００ｍ２／ｇ以下であることが更に好ましい。更に、ＣＮＴが主として開口したものにあっては、比表面積が１３００ｍ２／ｇ以上であることが好ましい。なお、本発明において、「比表面積」とは、ＢＥＴ法を用いて測定したＢＥＴ比表面積を指す。 CNT is obtained as an aligned CNT aggregate by the production method of the present invention, and its specific surface area is preferably 600 m 2 / g or more, more preferably 800 m 2 / g or more, and 2500 m 2 / g. Or less, more preferably 1400 m 2 / g or less. Furthermore, when the CNTs are mainly opened, the specific surface area is preferably 1300 m 2 / g or more. In the present invention, the “specific surface area” refers to the BET specific surface area measured using the BET method.
　ＣＮＴ配向集合体としての重量密度は０．００２ｇ／ｃｍ３以上、０．２ｇ／ｃｍ３以下であることが好ましい。重量密度が０．２ｇ／ｃｍ３以下であれば、ＣＮＴ配向集合体を構成するＣＮＴ同士の結びつきが弱くなるので、ＣＮＴ配向集合体を溶媒等に攪拌した際に、均質に分散させることが容易になる。また、重量密度が０．００２ｇ／ｃｍ３以上であれば、ＣＮＴ配向集合体の一体性を向上させ、バラけることを抑制できるため取扱いが容易になる。 The weight density of the aligned CNT aggregate 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, since the CNTs constituting the aligned CNT aggregate are weakened, it is easy to uniformly disperse the aligned CNT aggregate in a solvent or the like. become. Further, if the weight density is 0.002 g / cm 3 or more, the integrity of the aligned CNT aggregate can be improved, and the handling can be easily performed since it is possible to suppress the variation.
　ＣＮＴ配向集合体は高い配向度を有していることが好ましい。高い配向度を有するか否かは、以下の１．から３．の少なくともいずれか１つの方法によって評価することができる。 It is preferable that the aligned CNT aggregate has a high degree of orientation. Whether or not it has a high degree of orientation is as follows. To 3. It can be evaluated by at least one of the following methods.
　１．ＣＮＴの長手方向に平行な第１方向と、第１方向に直交する第２方向とからＸ線を入射してＸ線回折強度を測定（θ－２θ法）した場合に、第２方向からの反射強度が、第１方向からの反射強度より大きくなるθ角と反射方位とが存在し、かつ第１方向からの反射強度が、第２方向からの反射強度より大きくなるθ角と反射方位とが存在すること。 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 perpendicular 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．ＣＮＴの長手方向に直交する方向からＸ線を入射して得られた２次元回折パターン像でＸ線回折強度を測定（ラウエ法）した場合に、異方性の存在を示す回折ピークパターンが出現すること。 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．ヘルマンの配向係数が、θ－２θ法又はラウエ法で得られたＸ線回折強度を用いると０より大きく１より小さいこと、より好ましくは０．２５以上且つ１以下であること。 3. When the X-ray diffraction intensity obtained by the θ-2θ method or the Laue method is used, the Hermann orientation coefficient is greater than 0 and less than 1, more preferably 0.25 or more and 1 or less.
　ＣＮＴ配向集合体の高さ（長さ）としては、１０μｍ以上且つ１０ｃｍ以下の範囲にあることが好ましい。高さが１０μｍ以上であると、配向度が向上する。また高さが１０ｃｍ以下であると、生成を短時間で行なえるため炭素系不純物の付着を抑制でき、比表面積を向上できる。 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 degree of 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.
　ＣＮＴ配向集合体のＧ／Ｄ比は好ましくは２以上、更に好ましくは４以上である。Ｇ／Ｄ比とはＣＮＴの品質を評価するのに一般的に用いられている指標である。ラマン分光装置によって測定されるＣＮＴのラマンスペクトルには、Ｇバンド（１６００ｃｍ－１付近）とＤバンド（１３５０ｃｍ－１付近）と呼ばれる振動モードが観測される。ＧバンドはＣＮＴの円筒面であるグラファイトの六方格子構造由来の振動モードであり、Ｄバンドは非晶箇所に由来する振動モードである。よって、ＧバンドとＤバンドのピーク強度比（Ｇ／Ｄ比）が高いものほど、結晶性の高いＣＮＴと評価できる。 The G / D ratio of the aligned CNT aggregate is preferably 2 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.
　また、ＣＮＴ配向集合体は、精製処理を行わなくても、その純度は、通常、９８質量％以上、好ましくは９９．９質量％以上である。本発明の製造方法により得られるＣＮＴ配向集合体には不純物が殆ど混入しておらず、ＣＮＴ本来の諸特性を充分に発揮することができる。なお、純度は、蛍光Ｘ線を用いた元素分析により求めることができる。 Moreover, the purity of the aligned CNT aggregate is usually 98% by mass or more, and preferably 99.9% by mass or more, even if no purification treatment is performed. Impurities are hardly mixed in the aligned CNT aggregate obtained by the production method of the present invention, and the various characteristics inherent to CNT can be fully exhibited. The purity can be determined by elemental analysis using fluorescent X-rays.
　以下に実施例を挙げて、本発明を具体的に説明するが、本発明はこれらの実施例に限定されるものではない。 EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
　（基材）
　縦５００ｍｍ×横５００ｍｍ、厚さ０．６ｍｍのＦｅ－Ｃｒ合金ＳＵＳ４３０（ＪＦＥスチール株式会社製、Ｃｒ：１８質量％）の平板を用意した。レーザ顕微鏡を用いて複数個所の表面粗さを測定したところ、算術平均粗さＲａ≒０．０６３μｍであった。 (Base material)
A flat plate of Fe—Cr alloy SUS430 (manufactured by JFE Steel Co., Ltd., Cr: 18% by mass) having a length of 500 mm × width of 500 mm and a thickness of 0.6 mm was prepared. When the surface roughness at a plurality of locations was measured using a laser microscope, the arithmetic average roughness Ra was approximately 0.063 μm.
　（触媒の形成）
　上記の基材上に以下のような方法で触媒を形成した。まず、アルミニウムトリ－ｓｅｃ－ブトキシド１．９ｇを２－プロパノール１００ｍＬ（７８ｇ）に溶解させ、安定剤としてトリイソプロパノールアミン０．９ｇを加えて溶解させて、アルミナ膜形成用コーティング剤を調製した。ディップコーティングにより、室温２５℃、相対湿度５０％の環境下で基材上に上述のアルミナ膜形成用コーティング剤を塗布した。塗布条件としては、基材を浸漬後、２０秒間保持して、１０ｍｍ／秒の引き上げ速度で基板を引き上げた後、５分間風乾した。次に、３００℃の空気環境下で３０分間加熱した後、室温まで冷却した。これにより、基材上に膜厚４０ｎｍのアルミナ膜を形成した。 (Catalyst formation)
A catalyst was formed on the above substrate by the following method. First, 1.9 g of aluminum tri-sec-butoxide was dissolved in 100 mL (78 g) of 2-propanol, and 0.9 g of triisopropanolamine was added and dissolved as a stabilizer to prepare an alumina film-forming coating agent. By the dip coating, the above-mentioned coating agent for forming an alumina film was applied onto the substrate in an environment of room temperature of 25 ° C. and relative humidity of 50%. As the coating conditions, the substrate was immersed, held for 20 seconds, the substrate was lifted at a pulling rate of 10 mm / second, and then air-dried for 5 minutes. Next, after heating for 30 minutes in 300 degreeC air environment, it cooled to room temperature. Thereby, an alumina film having a film thickness of 40 nm was formed on the substrate.
　続いて、酢酸鉄１７４ｍｇを２－プロパノール１００ｍＬに溶解させ、安定剤としてトリイソプロパノールアミン１９０ｍｇを加えて溶解させて、鉄膜コーティング剤を調製した。ディップコーティングにより、室温２５℃、相対湿度５０％の環境下で、アルミナ膜が成膜された基材上に鉄膜コーティング剤を塗布した。塗布条件としては、基材を浸漬後、２０秒間保持して、３ｍｍ／秒の引き上げ速度で基板を引き上げた後、５分間風乾した。次に、１００℃の空気環境下で、３０分加熱した後、室温まで冷却した。これにより、膜厚３ｎｍの触媒生成膜を形成した。 Subsequently, 174 mg of iron acetate was dissolved in 100 mL of 2-propanol, and 190 mg of triisopropanolamine was added and dissolved as a stabilizer to prepare an iron film coating agent. By dip coating, an iron film coating agent was applied on a substrate on which an alumina film was formed in an environment at room temperature of 25 ° C. and a relative humidity of 50%. As the coating conditions, the substrate was immersed, held for 20 seconds, the substrate was lifted at a lifting speed of 3 mm / second, and then air-dried for 5 minutes. Next, after heating for 30 minutes in an air environment at 100 ° C., the mixture was cooled to room temperature. Thereby, a catalyst generation film having a film thickness of 3 nm was formed.
　以下、全ての実験例において、このように触媒が形成された基材を用いた。 Hereinafter, in all the experimental examples, the base material on which the catalyst was formed in this way was used.
　（実験例１）
　図１に示すようなバッチ式成長炉内でフォーメーション工程と成長工程とを順次行うことでＣＮＴを製造した。前述の触媒基材を縦４０ｍｍ×横４０ｍｍの大きさに切り出したものを触媒基材として用い、フォーメーション工程、成長工程を順次行なって基材表面にＣＮＴを製造した。各工程におけるガス流量、ガスの組成、加熱器の設定温度、及び処理時間を表１に示す。 (Experimental example 1)
CNTs were manufactured by sequentially performing a formation process and a growth process in a batch growth furnace as shown in FIG. Using the catalyst substrate cut out to a size of 40 mm in length and 40 mm in width as the catalyst substrate, a formation process and a growth process were sequentially performed to produce CNTs on the substrate surface. Table 1 shows the gas flow rate, gas composition, heater set temperature, and processing time in each step.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　触媒基材を設置する位置を変更することで原料ガス加熱時間を調整し、製造されるＣＮＴの収量及び比表面積のバランスが最も良い基材位置を決定した。まず始めに、触媒基材を設置しないで成長工程を実施し、基材設置位置近傍のガスを約２００ｓｃｃｍ吸引サンプリングしてガス分析を実施した。分析結果を表２に示す。 The raw material gas heating time was adjusted by changing the position where the catalyst base material was installed, and the base material position with the best balance between the yield and specific surface area of the produced CNTs was determined. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 2.
　なお、「原料ガス加熱時間」とは、原料ガスが炉内加熱領域に入ってから触媒基材に到達するまでの概算平均時間であり、以下の式により求められる。
　　原料ガス加熱時間［ｍｉｎ］＝（基材より上流側の加熱領域体積［ｍＬ］）／｛（ガス流量［ｓｃｃｍ］）×（炉温度［Ｋ］）×１／（２７３［Ｋ］）｝ The “raw material gas heating time” is an approximate average time from when the raw material gas enters the in-furnace heating region until it reaches the catalyst substrate, and is obtained by the following equation.
Raw material gas heating time [min] = (heating area volume [mL] upstream from the substrate) / {(gas flow rate [sccm]) × (furnace temperature [K]) × 1 / (273 [K])}
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２中、ＣＰＤはシクロペンタジエン、ｐＣ３Ｈ４はメチルアセチレン（プロピン）、ＶＡはビニルアセチレン、２Ｂは２－ブチン、ａＣ３Ｈ４はプロパジエン（アレン）、１３ＢＤは１，３－ブタジエン、ｔ－ＰＰＬはｔ－ピペリレン、Ｃ１０Ｈ８はナフタレンを意味する。以下の表においても同様である。表２以外の成分として、アセチレン類としては１－ブチン、ジアセチレン、フェニルアセチレンが、１，３－ブタジエン類としてはイソプレン、ｃ－ピペリレンが、シクロペンタジエン類としてはメチルシクロペンタジエンが、アレン類としては１，２－ブタジエンが、排気タール主成分のＰＡＨｓとしてはアセナフチレン、ビフェニル、フルオレン、フェナントレン、アントラセンが、それぞれ微量（１０ｐｐｍ以下）検出された。また、その他の成分として、水素、メタン、エチレン、エタン、プロピレン、ベンゼン、トルエン、スチレンなどが検出された。この実験例は、炭化水素Ｂの合計体積濃度［Ｂ］が０．２８％未満であるため、「比較例１」とする。
　上記条件で得られたＣＮＴの特性を評価した。結果を表３に示す。 In Table 2, CPD is cyclopentadiene, pC 3 H 4 is methylacetylene (propyne), VA is vinylacetylene, 2B is 2-butyne, aC 3 H 4 is propadiene (allene), 13BD is 1,3-butadiene, t -PPL means t-piperylene and C 10 H 8 means naphthalene. The same applies to the following tables. As components other than Table 2, acetylenes are 1-butyne, diacetylene, phenylacetylene, 1,3-butadienes isoprene, c-piperylene, cyclopentadiene is methylcyclopentadiene, and allenes are 1,2-butadiene was detected, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than 10 ppm) as PAHs mainly composed of exhaust tar. Further, hydrogen, methane, ethylene, ethane, propylene, benzene, toluene, styrene and the like were detected as other components. In this experimental example, since the total volume concentration [B] of hydrocarbon B is less than 0.28%, it is referred to as “Comparative Example 1.”
The characteristics of the CNT obtained under the above conditions were evaluated. The results are shown in Table 3.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　以下、比較例１の収量および炭素変換効率を基準として各実験例の収量および炭素変換効率を評価した。 Hereinafter, the yield and carbon conversion efficiency of each experimental example were evaluated based on the yield and carbon conversion efficiency of Comparative Example 1.
　（実験例２）
　実験例１と同様の製造装置を用い、成長工程における原料ガスの組成を表４のように変更してＣＮＴを製造した。表４に記載しない諸条件は実験例１と同様とした。 (Experimental example 2)
Using the same production apparatus as in Experimental Example 1, the composition of the raw material gas in the growth process was changed as shown in Table 4 to produce CNTs. Various conditions not described in Table 4 were the same as those in Experimental Example 1.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　各条件において、原料ガスのＣ２Ｈ２と１３ＢＤの濃度比（［Ａ’］／［Ｂ’］）を一定（０．４）とし、原料ガスに含まれる炭素原子濃度（以下、「炭素濃度」と呼ぶ。）を変えて実験を行った。また、各条件において、原料ガスに添加する水素Ｈ２および触媒賦活物質Ｈ２Ｏの濃度は、炭素濃度に比例するように変更した。 Under each condition, the concentration ratio ([A ′] / [B ′]) of C 2 H 2 and 13BD of the source gas is constant (0.4), and the concentration of carbon atoms contained in the source gas (hereinafter referred to as “carbon concentration”). ")." In each condition, the concentrations of hydrogen H 2 and catalyst activation material H 2 O added to the source gas were changed so as to be proportional to the carbon concentration.
　触媒基材を設置する位置を変更することで原料ガス加熱時間を調整した。まず始めに、触媒基材を設置しないで成長工程を実施し、基材設置位置近傍のガスを約２００ｓｃｃｍ吸引サンプリングしてガス分析を実施した。分析結果を表５に示す。 The raw material gas heating time was adjusted by changing the position where the catalyst base was installed. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 5.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　表５中、ＩＰはイソプレン、ｃ－ＰＰＬはｃ－ピペリレン、１２ＢＤは１，２－ブタジエンを意味する。以下の表においても同様である。表５以外の成分として、アセチレン類としてはジアセチレン、メチルビニルアセチレン、フェニルアセチレンが、シクロペンタジエン類としてはメチルシクロペンタジエンが、それぞれ極微量（数ｐｐｍ以下）検出された。排気タール主成分のＰＡＨｓとしてはナフタレンが最も多く数１０ｐｐｍ以下、その他成分はアセナフチレン、ビフェニル、フルオレン、フェナントレン、アントラセンが微量（１０ｐｐｍ以下）検出された。また、その他成分として、水素、メタン、エチレン、プロピレン、アセトン、ベンゼン、トルエン、スチレン等が検出された。 In Table 5, IP means isoprene, c-PPL means c-piperylene, and 12BD means 1,2-butadiene. The same applies to the following tables. As components other than those shown in Table 5, diacetylene, methylvinylacetylene, and phenylacetylene were detected as acetylenes, and methylcyclopentadiene was detected as trace amounts (several ppm or less) as cyclopentadienes. As the exhaust tar main component PAHs, naphthalene was the most, and several tens ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than 10 ppm) as other components. Further, hydrogen, methane, ethylene, propylene, acetone, benzene, toluene, styrene and the like were detected as other components.
　各条件で得られたＣＮＴの特性を評価した。結果を表６に示す。 The characteristics of the CNT obtained under each condition were evaluated. The results are shown in Table 6.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　接触ガスにおけるＣ２Ｈ２濃度（炭化水素Ａの濃度［Ａ］）が０．１％超過、且つ１３ＢＤ濃度（炭化水素Ｂの濃度［Ｂ］）が０．２８％以上の実施例２－１～実施例２－４では、比表面積を１０００ｍ２／ｇ以上に維持しつつ、比較例１と比較して、収量が約１．４倍～２．５倍に増加することが示された。また、炭素変換効率も約１．７倍～２．８倍に向上することが示された。 Example 2-1 in which C 2 H 2 concentration (hydrocarbon A concentration [A]) in the contact gas exceeds 0.1% and 13BD concentration (hydrocarbon B concentration [B]) is 0.28% or more In Examples 2-4, it was shown that the yield increased by about 1.4 to 2.5 times compared with Comparative Example 1 while maintaining the specific surface area at 1000 m 2 / g or more. It was also shown that the carbon conversion efficiency was improved by about 1.7 to 2.8 times.
　（実験例３）
　実験例１と同様の製造装置を用い、成長工程における原料ガスの組成を表７のように変更してＣＮＴを製造した。表７に記載しない諸条件は実験例２と同様とした。 (Experimental example 3)
Using the same production apparatus as in Experimental Example 1, the composition of the raw material gas in the growth process was changed as shown in Table 7 to produce CNTs. Various conditions not described in Table 7 were the same as those in Experimental Example 2.
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　各条件において、炭素濃度を一定（６．０％）とし、原料ガスのＣ２Ｈ２と１３ＢＤ濃度比（［Ａ’］／［Ｂ’］）を表７に示す通りに変えて製造を行った。また、各条件において、原料ガスに添加する水素Ｈ２の濃度は２．００％で一定とし、触媒賦活物質Ｈ２Ｏの濃度は０．０２％で一定とした。 Under each condition, the carbon concentration was constant (6.0%), and the C 2 H 2 and 13BD concentration ratio ([A ′] / [B ′]) of the source gas was changed as shown in Table 7 to perform the production. It was. In each condition, the concentration of hydrogen H 2 added to the raw material gas was constant at 2.00%, and the concentration of the catalyst activation material H 2 O was constant at 0.02%.
　触媒基材を設置する位置は実験例２と同じとした。まず始めに、触媒基材を設置しないで成長工程を実施し、基材設置位置近傍のガスを約２００ｓｃｃｍ吸引サンプリングしてガス分析を実施した。分析結果を表８に示す。 The position where the catalyst base is installed is the same as in Experimental Example 2. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 8.
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
　表８以外の成分として、アセチレン類としてはジアセチレン、フェニルアセチレン、メチルビニルアセチレンが、シクロペンタジエン類としてはメチルシクロペンタジエンが、それぞれ極微量（数ｐｐｍ以下）検出された。排気タール主成分のＰＡＨｓとしてはナフタレンが最も多く数１０ｐｐｍ以下、その他成分はアセナフチレン、ビフェニル、フルオレン、フェナントレン、アントラセンが極微量（数ｐｐｍ以下）検出された。また、その他成分として、水素、メタン、エチレン、アセトン、ベンゼン等が検出された。 As components other than Table 8, diacetylene, phenylacetylene and methylvinylacetylene were detected as acetylenes, and methylcyclopentadiene was detected as trace amounts (less than several ppm) as cyclopentadienes. As the exhaust tar main component PAHs, naphthalene was the most, and several tens of ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm) as other components. Moreover, hydrogen, methane, ethylene, acetone, benzene, etc. were detected as other components.
　各条件で得られたＣＮＴの特性を評価した。結果を表９に示す。 The characteristics of the CNT obtained under each condition were evaluated. The results are shown in Table 9.
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
　［Ａ］が０．１％超過且つ［Ｂ］が０．２８％以上である実施例３－１～実施例３－６では、比較例１よりも収量が１．２～２．０倍ほど増加し、且つ比表面積を９００ｍ２／ｇ以上に維持できることが示された。また、炭素変換効率も約１．６～２．７倍に向上することが示された。さらに、［Ａ］／［Ｂ］が０．１～８の範囲では特にこの傾向が顕著であった。 In Examples 3-1 to 3-6 in which [A] exceeds 0.1% and [B] is 0.28% or more, the yield is about 1.2 to 2.0 times that in Comparative Example 1. It was shown that the specific surface area can be increased and maintained at 900 m 2 / g or more. It was also shown that the carbon conversion efficiency was improved by about 1.6 to 2.7 times. Further, this tendency was particularly remarkable when [A] / [B] was in the range of 0.1 to 8.
　（実験例４）
　実験例１と同様の製造装置を用い、成長工程における原料ガスの組成を表１０のように、１，３－ブタジエン類（炭化水素Ｂ’）としてＩＰを用いてＣＮＴを製造した。表１０に記載しない諸条件は実験例１と同様とした。 (Experimental example 4)
Using the same production apparatus as in Experimental Example 1, CNTs were produced using IP as the 1,3-butadienes (hydrocarbon B ′) with the composition of the raw material gas in the growth process as shown in Table 10. Various conditions not listed in Table 10 were the same as those in Experimental Example 1.
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
　炭素濃度は６．０％とし、原料ガスのＣ２Ｈ２とＩＰの濃度比（［Ａ’］／［Ｂ’］）は０．４として製造を行った。 The carbon concentration was 6.0%, and the concentration ratio ([A ′] / [B ′]) of C 2 H 2 and IP of the source gas was 0.4.
　触媒基材を設置する位置は実験例２と同じとした。まず始めに、触媒基材を設置しないで成長工程を実施し、基材設置位置近傍のガスを約２００ｓｃｃｍ吸引サンプリングしてガス分析を実施した。分析結果を表１１に示す。 The position where the catalyst base is installed is the same as in Experimental Example 2. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 11.
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000011
　表１１以外の成分として、アセチレン類としては１－ブチン、メチルビニルアセチレン、フェニルアセチレンが、シクロペンタジエン類としてはメチルシクロペンタジエンが、それぞれ微量（１０ｐｐｍ以下）検出された。排気タール主成分のＰＡＨｓとしてはナフタレンが最も多く数１０ｐｐｍ以下、その他成分はアセナフチレン、ビフェニル、フルオレン、フェナントレン、アントラセンが極微量（数ｐｐｍ以下）検出された。また、その他成分として、水素、メタン、エチレン、プロピレン、ベンゼン、トルエンなどが検出された。 As components other than Table 11, 1-butyne, methylvinylacetylene, and phenylacetylene were detected as acetylenes, and trace amounts (10 ppm or less) of methylcyclopentadiene were detected as cyclopentadienes. As the exhaust tar main component PAHs, naphthalene was the most, and several tens of ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm) as other components. Further, hydrogen, methane, ethylene, propylene, benzene, toluene and the like were detected as other components.
　得られたＣＮＴの特性を評価した。結果を表１２に示す。 The characteristics of the obtained CNT were evaluated. The results are shown in Table 12.
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
　原料ガスの炭化水素Ｂ’をＩＰに変えても、比較例１と比較して収量が１．７倍に増加し、且つ比表面積を１０００ｍ２／ｇ以上に維持できることが示された。また、炭素変換効率も２．３倍に向上することが示された。 It was shown that even when the hydrocarbon B ′ of the source gas was changed to IP, the yield increased 1.7 times compared to Comparative Example 1, and the specific surface area could be maintained at 1000 m 2 / g or more. It was also shown that the carbon conversion efficiency was improved 2.3 times.
　（実験例５）
　実験例１と同様の製造装置を用い、成長工程における原料ガスの組成を表１３のように、アセチレン類（炭化水素Ａ’）としてｐＣ３Ｈ４、１，３－ブタジエン類（炭化水素Ｂ’）としてＩＰを用いてＣＮＴを製造した。表１３に記載しない諸条件は実験例１と同様とした。 (Experimental example 5)
Using the same production apparatus as in Experimental Example 1, the composition of the raw material gas in the growth process is pC 3 H 4 , 1,3-butadienes (hydrocarbon B ′) as acetylenes (hydrocarbon A ′) as shown in Table 13. ) Was used to produce CNTs using IP. The various conditions not listed in Table 13 were the same as in Experimental Example 1.
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
　原料ガス中の炭素濃度を６．０％とし、原料ガスのｐＣ３Ｈ４とＩＰの濃度比（［Ａ’］／［Ｂ’］）を０．４として製造を行った。 Manufacture was performed by setting the carbon concentration in the source gas to 6.0% and the concentration ratio ([A ′] / [B ′]) of pC 3 H 4 and IP in the source gas to 0.4.
　触媒基材を設置する位置は実験例２と同じとした。まず始めに、触媒基材を設置しないで成長工程を実施し、基材設置位置近傍のガスを約２００ｓｃｃｍ吸引サンプリングしてガス分析を実施した。分析結果を表１４に示す。 The position where the catalyst base is installed is the same as in Experimental Example 2. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 14.
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000014
　表１４以外の成分として、アセチレン類としては１－ブチン、メチルビニルアセチレン、フェニルアセチレンが、シクロペンタジエン類としてはメチルシクロペンタジエンが、それぞれ微量（１０ｐｐｍ以下）検出された。排気タール主成分のＰＡＨｓとしてはナフタレンが最も多く数１０ｐｐｍ以下、その他成分はアセナフチレン、ビフェニル、フルオレン、フェナントレン、アントラセンが極微量（数ｐｐｍ以下）検出された。また、その他成分として、水素、メタン、エチレン、プロピレン、ベンゼン、トルエンなどが検出された。 As components other than Table 14, 1-butyne, methylvinylacetylene, and phenylacetylene were detected as acetylenes, and trace amounts (10 ppm or less) of methylcyclopentadiene were detected as cyclopentadienes. As the exhaust tar main component PAHs, naphthalene was the most, and several tens of ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm) as other components. Further, hydrogen, methane, ethylene, propylene, benzene, toluene and the like were detected as other components.
　得られたＣＮＴの特性を評価した。結果を表１５に示す。 The characteristics of the obtained CNT were evaluated. The results are shown in Table 15.
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
　原料ガスの炭化水素Ａ’をｐＣ３Ｈ４、炭化水素Ｂ’をＩＰに変えても、比較例１と比較して収量が１．４倍に増加し、且つ比表面積を１０００ｍ２／ｇ以上に維持できることが示された。また、炭素変換効率も１．８倍に向上することが示された。 Even if the hydrocarbon A ′ of the source gas is changed to pC 3 H 4 and the hydrocarbon B ′ is changed to IP, the yield is increased by a factor of 1.4 compared with Comparative Example 1, and the specific surface area is 1000 m 2 / g or more. It was shown that it can be maintained. It was also shown that the carbon conversion efficiency was improved by 1.8 times.
　（実験例６）
　実験例１と同様の製造装置を用い、成長工程における原料ガスの組成を表１６のように変更してＣＮＴを製造した。表１６に記載しない諸条件は実験例１と同様とした。 (Experimental example 6)
Using the same production apparatus as in Experimental Example 1, the composition of the raw material gas in the growth process was changed as shown in Table 16 to produce CNTs. Various conditions not described in Table 16 were the same as those in Experimental Example 1.
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000016
　各条件において、炭素濃度を一定（４．０％）とし、原料ガスのＣ２Ｈ２の体積濃度［Ａ’］と１３ＢＤの体積濃度［Ｂ’］の比［Ａ’］／［Ｂ’］を表１６に示す通りに変えて製造を行った。また、各条件において、原料ガスに添加する水素Ｈ２の濃度は１．３３％で一定とし、触媒賦活物質Ｈ２Ｏの濃度は０．０１％で一定とした。 Under each condition, the carbon concentration is constant (4.0%), and the ratio [A ′] / [B ′] of the volume concentration [A ′] of C 2 H 2 of the source gas and the volume concentration [B ′] of 13BD. Were manufactured as shown in Table 16. In each condition, the concentration of hydrogen H 2 added to the raw material gas was constant at 1.33%, and the concentration of the catalyst activation material H 2 O was constant at 0.01%.
　触媒基材を設置する位置は実験例２と同じとした。まず始めに、触媒基材を設置しないで成長工程を実施し、基材設置位置近傍のガスを約２００ｓｃｃｍ吸引サンプリングしてガス分析を実施した。分析結果を表１７に示す。 The position where the catalyst base is installed is the same as in Experimental Example 2. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 17.
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000017
　表１７以外の成分として、アセチレン類としてはジアセチレン、フェニルアセチレンが、シクロペンタジエン類としてはメチルシクロペンタジエンが、それぞれ極微量（数ｐｐｍ以下）検出された。排気タール主成分ＰＡＨｓのその他成分としてはアセナフチレン、ビフェニル、フルオレン、フェナントレン、アントラセンが極微量（数ｐｐｍ以下）検出された。また、その他成分として、水素、メタン、エチレン、ベンゼンなどが検出された。 As components other than those shown in Table 17, diacetylene and phenylacetylene were detected as acetylenes, and methylcyclopentadiene was detected as trace amounts (less than several ppm) as cyclopentadienes. As other components of the exhaust tar main component PAHs, acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm). In addition, hydrogen, methane, ethylene, benzene and the like were detected as other components.
　各条件で得られたＣＮＴの特性を評価した。結果を表１８に示す。 The characteristics of the CNT obtained under each condition were evaluated. The results are shown in Table 18.
Figure JPOXMLDOC01-appb-T000018
Figure JPOXMLDOC01-appb-T000018
　原料ガスがエチレンの場合（比較例１）とで比較して、［Ａ’］／［Ｂ’］が０．１～６の範囲になる実施例６－１～実施例６－４では、比表面積、Ｇ／Ｄ、収量のいずれもほぼ同等以上を維持しつつ、炭素変換効率が１．８倍～２．８倍に向上しつつ、排気タール主成分であるナフタレン濃度が比較例１の約１／２０以下に低減していることが示された。 In Examples 6-1 to 6-4 in which [A ′] / [B ′] is in the range of 0.1 to 6, compared with the case where the source gas is ethylene (Comparative Example 1), the ratio is While maintaining almost the same surface area, G / D, and yield, the carbon conversion efficiency is improved by 1.8 to 2.8 times, and the concentration of naphthalene, which is the main component of exhaust tar, is about that of Comparative Example 1. It was shown that it was reduced to 1/20 or less.
　（実験例７）
　実験例１と同様の製造装置を用い、成長工程における原料ガスの組成を表１９のように、Ｃ２Ｈ２と１３ＢＤの他に炭化水素Ｃ’としてシクロペンテン（ＣＰＥ）を添加してＣＮＴを製造した。表１９に記載しない諸条件は実験例１と同様とした。 (Experimental example 7)
Using the same production equipment as in Experimental Example 1, the composition of the raw material gas in the growth process is as shown in Table 19 to produce CNTs by adding cyclopentene (CPE) as hydrocarbon C ′ in addition to C 2 H 2 and 13BD. did. Various conditions not described in Table 19 were the same as those in Experimental Example 1.
Figure JPOXMLDOC01-appb-T000019
Figure JPOXMLDOC01-appb-T000019
　各条件において、原料ガス中の炭素濃度を一定（６．０％）とし、原料ガスのＣ２Ｈ２と１３ＢＤの濃度比（［Ａ’］／［Ｂ’］）及びＣＰＥの濃度を表１９に示す通りに変えて製造を行った。 Under each condition, the carbon concentration in the raw material gas was constant (6.0%), and the concentration ratio of C 2 H 2 and 13BD ([A ′] / [B ′]) and the concentration of CPE in the raw material gas are shown in Table 19. The production was carried out by changing as shown in FIG.
　触媒基材を設置する位置は実験例２と同じとした。まず始めに、触媒基材を設置しないで成長工程を実施し、基材設置位置近傍のガスを約２００ｓｃｃｍ吸引サンプリングしてガス分析を実施した。分析結果を表２０に示す。 The position where the catalyst base is installed is the same as in Experimental Example 2. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 20.
Figure JPOXMLDOC01-appb-T000020
Figure JPOXMLDOC01-appb-T000020
　表２０以外の成分として、アセチレン類としてはジアセチレン、フェニルアセチレンが、シクロペンタジエン類としてはメチルシクロペンタジエンが、それぞれ微量（１０ｐｐｍ以下）検出された。排気タール主成分ＰＡＨｓのその他成分としてはアセナフチレン、ビフェニル、フルオレン、フェナントレン、アントラセンが極微量（数ｐｐｍ以下）検出された。また、その他成分として、水素、メタン、エチレン、シクロペンテン、ベンゼン等が検出された。 As components other than Table 20, trace amounts (10 ppm or less) of diacetylene and phenylacetylene as acetylenes and methylcyclopentadiene as cyclopentadiene were detected. As other components of the exhaust tar main component PAHs, acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm). Further, hydrogen, methane, ethylene, cyclopentene, benzene and the like were detected as other components.
　得られたＣＮＴの特性を評価した。結果を表２１に示す。 The characteristics of the obtained CNT were evaluated. The results are shown in Table 21.
Figure JPOXMLDOC01-appb-T000021
Figure JPOXMLDOC01-appb-T000021
　原料ガスに炭化水素Ｃ’を添加することで、比較例１と比較して、収量が２．１倍以上に増加し、且つ比表面積を８００ｍ２／ｇ以上に維持できることが示された。また、比較例１と比較して、炭素変換効率も２．７倍以上に向上することが示された。また、排気タール主成分であるナフタレン濃度が比較例１の約１／１６以下に低減していることが示された。 It was shown that by adding hydrocarbon C ′ to the raw material gas, the yield increased 2.1 times or more and the specific surface area could be maintained at 800 m 2 / g or more as compared with Comparative Example 1. Moreover, compared with the comparative example 1, it was shown that carbon conversion efficiency improves 2.7 times or more. Further, it was shown that the concentration of naphthalene, which is a main component of exhaust tar, is reduced to about 1/16 or less of that of Comparative Example 1.
　（実験例８）
　図２に示すようなバッチ式成長炉内でフォーメーション工程と成長工程とを順次行うことでＣＮＴを製造した。前述の触媒基材を縦４０ｍｍ×横１２０ｍｍの大きさに切り出したものを触媒基材として用い、フォーメーション工程、成長工程を順次行なって基材表面にＣＮＴを製造した。各工程におけるガス流量、ガスの組成、加熱器の設定温度、および処理時間を表２２に示す。 (Experimental example 8)
CNTs were manufactured by sequentially performing a formation process and a growth process in a batch type growth furnace as shown in FIG. A CNT was produced on the surface of the base material by sequentially performing a formation process and a growth process using the above-mentioned catalyst base material cut into a size of 40 mm long × 120 mm wide as a catalyst base material. Table 22 shows the gas flow rate, gas composition, heater set temperature, and processing time in each step.
Figure JPOXMLDOC01-appb-T000022
Figure JPOXMLDOC01-appb-T000022
　炭素濃度は６．０％とし、原料ガスのＣ２Ｈ２と１３ＢＤの濃度比（［Ａ’］／［Ｂ’］）は０．４として製造を行った。 The carbon concentration was 6.0%, and the concentration ratio ([A ′] / [B ′]) of C 2 H 2 and 13BD of the raw material gas was 0.4.
　触媒基材を設置する位置を変更することで原料ガス加熱時間を調整した。まず始めに、触媒基材を設置しないで成長工程を実施し、基材設置位置近傍のガスを約２００ｓｃｃｍ吸引サンプリングしてガス分析を実施した。分析結果を表２３に示す。 The raw material gas heating time was adjusted by changing the position where the catalyst base was installed. First, the growth process was carried out without installing the catalyst base material, and the gas in the vicinity of the base material installation position was sampled by suction at about 200 sccm for gas analysis. The analysis results are shown in Table 23.
Figure JPOXMLDOC01-appb-T000023
Figure JPOXMLDOC01-appb-T000023
　表２３以外の成分として、アセチレン類としてはジアセチレン、メチルビニルアセチレン、フェニルアセチレンが、シクロペンタジエン類としてはメチルシクロペンタジエンが、それぞれ極微量（数ｐｐｍ以下）検出され、排気タール主成分のＰＡＨｓとしてはナフタレンが最も多く数１０ｐｐｍ以下、その他成分はアセナフチレン、ビフェニル、フルオレン、フェナントレン、アントラセンが極微量（数ｐｐｍ以下）検出された。また、その他成分として、水素、メタン、エチレン、プロピレン、ベンゼン、トルエンなどが検出された。 As components other than Table 23, diacetylene, methylvinylacetylene, and phenylacetylene were detected as acetylenes, and methylcyclopentadiene was detected as a trace amount (less than several ppm) as cyclopentadienes, respectively. Naphthalene was the most abundant and several tens of ppm or less, and acenaphthylene, biphenyl, fluorene, phenanthrene, and anthracene were detected in trace amounts (less than several ppm) as other components. Further, hydrogen, methane, ethylene, propylene, benzene, toluene and the like were detected as other components.
　上記条件で得られたＣＮＴの特性を評価した。結果を表２４に示す。 The characteristics of the CNT obtained under the above conditions were evaluated. The results are shown in Table 24.
Figure JPOXMLDOC01-appb-T000024
Figure JPOXMLDOC01-appb-T000024
　比較例１と比較して収量が１．８倍ほど増加し、且つ比表面積を１０００ｍ２／ｇ以上に維持し、炭素変換効率においては約１７倍に向上することが示された。 It was shown that the yield increased by about 1.8 times compared with Comparative Example 1, the specific surface area was maintained at 1000 m 2 / g or more, and the carbon conversion efficiency was improved about 17 times.
　（実験例９）
　図３に示すような連続式成長炉内で、フォーメーション工程と成長工程を含む工程を連続的に行なうことでＣＮＴ配向集合体を製造した。前述の触媒基材をそのまま（縦５００ｍｍ×横５００ｍｍ）製造装置のメッシュベルト上に載置し、メッシュベルトの搬送速度を変更しながら基材上にＣＮＴ配向集合体を製造した。製造装置の各部の条件を表２５に示す。 (Experimental example 9)
In the continuous growth furnace as shown in FIG. 3, an aligned CNT aggregate was manufactured by continuously performing a process including a formation process and a growth process. The above-mentioned catalyst base material was placed on the mesh belt of the production apparatus as it was (length: 500 mm × width: 500 mm), and an aligned CNT aggregate was produced on the base material while changing the conveying speed of the mesh belt. Table 25 shows the conditions of each part of the manufacturing apparatus.
Figure JPOXMLDOC01-appb-T000025
Figure JPOXMLDOC01-appb-T000025
　成長ユニット３内、触媒基材が通過する位置近傍にガスサンプリングのためのプローブを設置し、触媒基材を通過させないこと以外は、ＣＮＴ配向集合体を製造する場合と同様の条件で装置を作動させて空炉のまま炉内を加熱し、前記プローブでガスをサンプリングし、得られたガスのガス分析を行った結果、接触ガスの組成は実施例８とほぼ同等の結果であり、５００ｍｍ×５００ｍｍの大型基材上に実験例８とほぼ同等のＣＮＴが均一に製造できることが確認できた。 The equipment is operated under the same conditions as in the case of producing aligned CNT aggregates, except that a probe for gas sampling is installed in the growth unit 3 in the vicinity of the position where the catalyst substrate passes, and the catalyst substrate is not allowed to pass. As a result of heating the inside of the furnace with an empty furnace, sampling the gas with the probe, and performing a gas analysis of the obtained gas, the composition of the contact gas is almost the same as in Example 8, 500 mm × It was confirmed that CNTs substantially equivalent to Experimental Example 8 could be uniformly produced on a 500 mm large substrate.
　本発明の炭素ナノ構造体の製造方法によれば、高品質な炭素ナノ構造体を高効率に製造することができる。 According to the method for producing a carbon nanostructure of the present invention, a high-quality carbon nanostructure can be produced with high efficiency.
　１００、２００、３００　ＣＮＴ製造装置
　１０２　反応炉
　１０４　加熱器
　１０６　ガス供給口
　１０８　排気口
　１１０　ホルダー
　１１２　シャワーヘッド
　１　入り口パージ部
　２　フォーメーションユニット
　２Ａ　フォーメーション炉
　２Ｂ　還元ガス噴射部
　２Ｃ　ヒーター
　３　成長ユニット
　３Ａ　成長炉
　３Ｂ　原料ガス噴射部
　３Ｃ　ヒーター
　３Ｄ　排気口
　４　冷却ユニット
　４Ａ　冷却炉
　４Ｂ　冷却ガス噴射部
　４Ｃ　水冷冷却管
　５　出口パージ部
　６　搬送ユニット
　６Ａ　メッシュベルト
　６Ｂ　ベルト駆動部
　７、８、９　接続部
　１０　触媒基材
　１１、１２、１３　ガス混入防止手段
　１１Ａ、１２Ａ、１３Ａ　排気部
　１１Ｂ、１２Ｂ、１３Ｂ　シールガス噴射部 100, 200, 300 CNT manufacturing apparatus 102 Reactor 104 Heater 106 Gas supply port 108 Exhaust port 110 Holder 112 Shower head 1 Entrance purge unit 2 Formation unit 2A Formation furnace 2B Reducing gas injection unit 2C Heater 3 Growth unit 3A Growth reactor 3B Raw material gas injection unit 3C heater 3D exhaust port 4 cooling unit 4A cooling furnace 4B cooling gas injection unit 4C water cooling cooling pipe 5 outlet purge unit 6 transport unit 6A mesh belt 6B belt driving unit 7, 8, 9 connection unit 10 catalyst base 11 , 12, 13 Gas mixing prevention means 11A, 12A, 13A Exhaust part 11B, 12B, 13B Seal gas injection part

Claims (10)

  1. 　原料ガスを触媒に供給し、化学気相成長法によって炭素ナノ構造体を成長させる炭素ナノ構造体の製造方法であって、
    　前記原料ガスに由来し、前記触媒に接触するガスＸが、アセチレン骨格を少なくとも１つ有する炭化水素Ａと、１，３－ブタジエン骨格を少なくとも１つ有する炭化水素Ｂと、を含み、
    　前記炭化水素Ａの合計体積濃度［Ａ］が０．１％超過、前記炭化水素Ｂの合計体積濃度［Ｂ］が０．２８％以上である
    　ことを特徴とする炭素ナノ構造体の製造方法。     A method for producing a carbon nanostructure in which a raw material gas is supplied to a catalyst and a carbon nanostructure is grown by chemical vapor deposition,
    Gas X derived from the raw material gas and contacting the catalyst contains hydrocarbon A having at least one acetylene skeleton and hydrocarbon B having at least one 1,3-butadiene skeleton,
    The method for producing a carbon nanostructure, wherein the total volume concentration [A] of the hydrocarbon A exceeds 0.1%, and the total volume concentration [B] of the hydrocarbon B is 0.28% or more.
  2. 　前記ガスＸが、
    　０．１≦［Ａ］／［Ｂ］≦８
    　を満たす請求項１に記載の炭素ナノ構造体の製造方法。     The gas X is
    0.1 ≦ [A] / [B] ≦ 8
    The manufacturing method of the carbon nanostructure of Claim 1 which satisfy | fills.
  3. 　前記ガスＸが、触媒賦活物質及び／又は水素分子をさらに含む請求項１又は２に記載の炭素ナノ構造体の製造方法。 The method for producing a carbon nanostructure according to claim 1 or 2, wherein the gas X further contains a catalyst activator and / or a hydrogen molecule.
  4. 　前記ガスＸが、シクロペンタジエン骨格を少なくとも１つ有する炭化水素Ｃをさらに含む請求項１～３のいずれか１項に記載の炭素ナノ構造体の製造方法。 The method for producing a carbon nanostructure according to any one of claims 1 to 3, wherein the gas X further includes a hydrocarbon C having at least one cyclopentadiene skeleton.
  5. 　原料ガスを触媒に供給し、化学気相成長法によって炭素ナノ構造体を成長させる炭素ナノ構造体の製造方法であって、
    　前記原料ガスが、アセチレン骨格を少なくとも１つ有する炭化水素Ａ’と、１，３－ブタジエン骨格を少なくとも１つ有する炭化水素Ｂ’と、を含む
    　ことを特徴とする炭素ナノ構造体の製造方法。     A method for producing a carbon nanostructure in which a raw material gas is supplied to a catalyst and a carbon nanostructure is grown by chemical vapor deposition,
    The method for producing a carbon nanostructure, wherein the source gas contains a hydrocarbon A ′ having at least one acetylene skeleton and a hydrocarbon B ′ having at least one 1,3-butadiene skeleton.
  6. 　前記炭化水素Ａ’の合計体積濃度を［Ａ’］、前記炭化水素Ｂ’の合計体積濃度を［Ｂ’］としたときに、前記原料ガスが、
    　０．１≦［Ａ’］／［Ｂ’］≦６
    　を満たす請求項５に記載の炭素ナノ構造体の製造方法。     When the total volume concentration of the hydrocarbon A ′ is [A ′] and the total volume concentration of the hydrocarbon B ′ is [B ′], the source gas is
    0.1 ≦ [A ′] / [B ′] ≦ 6
    The manufacturing method of the carbon nanostructure of Claim 5 which satisfy | fills.
  7. 　前記原料ガスが、触媒賦活物質及び／又は水素分子をさらに含む請求項５又は６に記載の炭素ナノ構造体の製造方法。 The method for producing a carbon nanostructure according to claim 5 or 6, wherein the source gas further contains a catalyst activator and / or hydrogen molecules.
  8. 　前記原料ガスが、炭素数５の炭素環を少なくとも１つ有する炭化水素Ｃ’をさらに含む請求項５～７のいずれか１項に記載の炭素ナノ構造体の製造方法。 The method for producing a carbon nanostructure according to any one of claims 5 to 7, wherein the source gas further contains a hydrocarbon C 'having at least one carbon ring having 5 carbon atoms.
  9. 　前記触媒が基材表面に担持されており、前記原料ガスをガスシャワーによって前記触媒に供給する請求項１～８のいずれか１項に記載の炭素ナノ構造体の製造方法。 The method for producing a carbon nanostructure according to any one of claims 1 to 8, wherein the catalyst is supported on a substrate surface, and the source gas is supplied to the catalyst by a gas shower.
  10. 　前記炭素ナノ構造体がカーボンナノチューブである請求項１～９のいずれか１項に記載の炭素ナノ構造体の製造方法。 The method for producing a carbon nanostructure according to any one of claims 1 to 9, wherein the carbon nanostructure is a carbon nanotube.
PCT/JP2016/001517 2015-03-25 2016-03-16 Method for producing carbon nanostructure WO2016152105A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2017507481A JP6673337B2 (en) 2015-03-25 2016-03-16 Method for producing carbon nanostructure

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2015-062940 2015-03-25
JP2015062940 2015-03-25

Publications (1)

Publication Number Publication Date
WO2016152105A1 true WO2016152105A1 (en) 2016-09-29

Family

ID=56978233

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2016/001517 WO2016152105A1 (en) 2015-03-25 2016-03-16 Method for producing carbon nanostructure

Country Status (2)

Country Link
JP (1) JP6673337B2 (en)
WO (1) WO2016152105A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016183058A (en) * 2015-03-25 2016-10-20 日本ゼオン株式会社 Method of producing carbon nano structure

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007261895A (en) * 2006-03-29 2007-10-11 Toray Ind Inc Method and apparatus for manufacturing carbon nanotube
JP2008056523A (en) * 2006-08-30 2008-03-13 Toray Ind Inc Method for producing carbon nanotube
JP2010173889A (en) * 2009-01-29 2010-08-12 Showa Denko Kk Carbon nanotube production apparatus and carbon nanotube production method
WO2011108269A1 (en) * 2010-03-02 2011-09-09 昭和電工株式会社 Process for production of carbon fibers
JP2012530663A (en) * 2009-06-17 2012-12-06 マサチューセッツ インスティテュート オブ テクノロジー Growth of carbon nanostructures assisted by alkynes

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007261895A (en) * 2006-03-29 2007-10-11 Toray Ind Inc Method and apparatus for manufacturing carbon nanotube
JP2008056523A (en) * 2006-08-30 2008-03-13 Toray Ind Inc Method for producing carbon nanotube
JP2010173889A (en) * 2009-01-29 2010-08-12 Showa Denko Kk Carbon nanotube production apparatus and carbon nanotube production method
JP2012530663A (en) * 2009-06-17 2012-12-06 マサチューセッツ インスティテュート オブ テクノロジー Growth of carbon nanostructures assisted by alkynes
WO2011108269A1 (en) * 2010-03-02 2011-09-09 昭和電工株式会社 Process for production of carbon fibers

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016183058A (en) * 2015-03-25 2016-10-20 日本ゼオン株式会社 Method of producing carbon nano structure

Also Published As

Publication number Publication date
JPWO2016152105A1 (en) 2018-01-11
JP6673337B2 (en) 2020-03-25

Similar Documents

Publication Publication Date Title
JP6365547B2 (en) Carbon nanostructure manufacturing method and carbon nanotube
JP5649225B2 (en) Equipment for producing aligned carbon nanotubes
JP5574265B2 (en) Equipment for producing aligned carbon nanotubes
WO2009128349A1 (en) Equipment and method for producing orientated carbon nano-tube aggregates
JP5590603B2 (en) Equipment for producing aligned carbon nanotubes
WO2009107603A1 (en) Process and apparatus for producing carbon nanotube, carbon nanotube fiber, and the like
JP6079539B2 (en) Method for producing carbon nanostructure
JPWO2014208097A1 (en) Method for producing carbon nanotube
WO2017170579A1 (en) Method for producing carbon nanostructure aggregate and carbon nanostructure aggregate
JP5622101B2 (en) Method for producing aligned carbon nanotube assembly
JP5700819B2 (en) Method for producing aligned carbon nanotube assembly
JP6673337B2 (en) Method for producing carbon nanostructure
JP6171805B2 (en) Method for producing carbon nanostructure
JP6387878B2 (en) Method for producing carbon nanostructure
JP6458594B2 (en) Method for producing carbon nanostructure including carbon nanotube
JP6673339B2 (en) Method for producing carbon nanostructure including carbon nanotube
WO2016072096A1 (en) Carbon nano structure aggregate and method for producing same
JP2016088814A (en) Graphene nano tape, carbon nano structure aggregate, and method for producing the same

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16768012

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2017507481

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16768012

Country of ref document: EP

Kind code of ref document: A1