JP2003146634A - Carbon nanotube and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new carbon nanotube characterized in that the carbon nanotube is susceptible to the addition of a functional group to the surface thereof due to the amorphous structure of the outer region of the wall portions thereof and exhibits high electric conductivity and high strength due to the crystalline structure of the inner region of the wall portion thereof. SOLUTION: The carbon nanotube has <=500 nm outer diameter and >=50 nm length and has the wall portion composed of carbon and is characterized in that the outer region of the wall portion has an amorphous structure and the inner region of the wall portion has a crystalline structure.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a carbon nanotube and a method for producing the same. The carbon nanotubes referred to here have a structure in which a graphite layer (graphene sheet) in which carbon 6-membered rings are continuous is rolled up, and the outer diameter is n.
It is a hollow carbon fiber of m size. Carbon nanotubes are used as electron emission materials, hydrogen storage materials, adsorption filtration materials, electrically conductive materials, and the like.

[0002]

2. Description of the Related Art As a conventionally known method for producing carbon nanotubes, an arc discharge method, a laser evaporation method, a vapor phase method (thermal CVD method) and the like have been proposed. Specifically, the arc discharge method is disclosed in, for example, JP-A-7-165406.
The laser evaporation method is proposed, for example, in Japanese Patent Application Laid-Open No. 10-273308, and the vapor phase method (thermal CVD method) is, for example, Japanese Patent Publication No. 3-64606. , Japanese Patent Publication No. 3-77288.

However, the arc discharge method and the laser evaporation method are low in productivity and are not suitable for mass production because of high cost. On the other hand, the vapor phase method
Mass production is possible, but Fe, Co, N
Since a transition metal such as i is used as a catalyst, there is a problem in that the product contains, for example, several% by weight of a metal component, and a post-process for removing the metal component is required. Further, since a metal component is present during the reaction, a side reaction is likely to occur, and there is a drawback that the amorphous carbon component other than carbon nanotubes is increased in the product. Furthermore, in the gas phase method, in order to control the outer diameter and wall thickness of carbon nanotubes, it is necessary to use metal fine particles whose size is controlled on a nanoscale or to add a purification step, which is industrially necessary. High-level mass production technology has a problem of high cost.

Further, when carbon nanotubes are used as industrial materials, surface modification techniques such as imparting functional groups to the surface of carbon nanotubes are important. It is considered that such a technique is indispensable not only for solubilization in a solvent but also for improving dispersibility in a resin and forming a composite material with a functional inorganic material and a biological material. Examples of the technique for solubilizing carbon nanotubes by adding a functional group to the surface include, for example,
"J. Chen, MA Hamon, HH
u, Y. Chen, A .; P. Rao, P. C. E
klund and R.K. C. Haddon, Sci
ence, 282, 95 (1998). "

At the outer peripheral portion of many conventionally known carbon nanotubes, the graphene sheet is in a cylindrical shape and has high crystallinity. Therefore, it is difficult to add a functional group to the surface of the nanotube. Even in the above-mentioned solubilization example, the functional group is added to the tip portion of the carbon nanotube, and the functional group is not added to the surface of the cylindrical portion having high crystallinity. In the method of providing a functional group only to the tip of the carbon nanotube, the number of functional groups in the entire carbon nanotube is limited, and thus it is difficult to solubilize a long carbon nanotube.

On the other hand, for example, WO 00/40509 discloses a carbon nanotube having a low overall crystallinity. Carbon nanotubes with low overall crystallinity can be synthesized, for example, by lowering the reaction conditions in the gas phase method, and it is expected that many functional groups can be added due to the low crystallinity of the surface. it can. However, for carbon nanotubes with low overall crystallinity,
It can be easily imagined that the carbon nanotubes with high crystallinity lose the advantages such as high conductivity and strong strength because the crystallinity is low to the inside.

Further, for example, according to Japanese Patent Publication No. 3-64606 and Japanese Patent Publication No. 3-77288, carbon nanotubes having a high degree of crystallinity on the outside and containing irregularly arranged carbon inside the carbon nanotubes. Is proposed. In order to impart a functional group to the irregularly arranged carbon inside the tube, a treatment for opening the tip of the tube is required in advance. Therefore, the above proposal has more technical problems than the method of imparting a functional group to the tube surface, and even if the functional group is imparted to the central portion, the functional group is imparted to the outer surface of the tube. It is difficult to expect the same effects (solubilization, etc.) as carbon nanotubes.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to easily add a functional group to the surface because the outer region of the wall of the carbon nanotube has an amorphous structure. Another object of the present invention is to provide a novel carbon nanotube, which is characterized by high electrical conductivity and strength because the inner region of the wall of the carbon nanotube has a crystalline structure. Another object of the present invention is an inexpensive solid phase method, which enables high-yield mass production of carbon nanotubes, and can easily control properties such as the outer diameter and thickness of carbon nanotubes. Another object of the present invention is to provide an industrially advantageous method for producing carbon nanotubes, in which the obtained carbon nanotubes do not contain a metal component.

[0009]

That is, the present invention comprises a plurality of related inventions, and the gist of each invention is as follows (1) to (6).

(1) Outer diameter is 500 nm or less and length is 50
A carbon nanotube having a thickness of nm or more, wherein the outer region of the wall has an amorphous structure and the inner region has a crystalline structure.

(2) Resin precursor particles which decompose and disappear by heating are coated with a carbon precursor resin, and have an average particle diameter of 10 to 100.
A method for producing a carbon nanotube, which comprises melt-spinning particles having a Cv value of 30 nm or less of 00 nm and a particle diameter, appropriately infusibilizing treatment, and then heating and firing to carbonize.

(3) Resin precursor particles which decompose and disappear by heating are coated with a carbon precursor resin, and have an average particle size of 10 to 100.
00 nm particles, particles having a Cv value of 30% or less of the particle size are dispersed in a matrix resin that decomposes and disappears by heating to obtain a dispersion, and then the obtained dispersion is melt-spun and appropriately infusibilized. After that, a method for producing carbon nanotubes, characterized by comprising heating and firing to carry out carbonization treatment.

(4) chemically grown by a polymerization method,
The surface of the resin fine particles that decompose and disappear by heating is chemically coated with a carbon precursor resin, and then dispersed in a matrix resin that decomposes and disappears by heating to obtain a dispersion.
A method for producing carbon nanotubes, characterized in that the obtained dispersion is melt-spun, appropriately infusibilized, and then heated and fired to be carbonized.

(5) Subsequent to the polymerization of the resin monomer which decomposes and disappears by heating, the component containing the monomer of the carbon precursor resin is charged and polymerized, and then the monomer of the resin which decomposes and disappears by heating is charged and polymerized. A method for producing carbon nanotubes, characterized in that the fine particles obtained by the above are subjected to melt-spinning, subjected to infusibilization treatment as appropriate, and then heat-fired for carbonization treatment.

(6) Resin fine particles which decompose and disappear by heating are coated with a carbon precursor resin, and then a resin which decomposes and disappears by heating is further coated, and then the obtained particles are melt-spun and appropriately infusibilized. After that, a method for producing carbon nanotubes, characterized by comprising heating and firing to carry out carbonization treatment.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The carbon nanotube of the present invention has an outer diameter of 500 nm or less and a length of 50 nm or more. The outer diameter of the carbon nanotube is preferably 200
nm or less, more preferably 100 nm or less. The lower limit of the outer diameter is usually 1 nm. Further, the length of the carbon nanotube is preferably 10 times or more the diameter, more preferably 100 times or more the diameter. The upper limit of the length is usually 10 cm.

The carbon nanotube of the present invention is
The outer region of the wall has an amorphous structure and the inner region of the wall has a crystalline structure. Here, the outer region of the wall means a range of 49% in the thickness direction from the outer wall, preferably 30%.
Up to 20%, more preferably up to 20%,
The inner region of the wall is 50 to 10 in the thickness direction from the outer wall.
It refers to a range of up to 0%, preferably 70 to 100%, more preferably up to 80%.

The above-mentioned structure of the carbon nanotube of the present invention uses a transmission electron microscope image of the carbon nanotube having a magnification of 1,000,000 times or more and a distance between adjacent pixels of 0.06 nm or less. The ratio of B to A (B / A) or the ratio of D to C (D / C) obtained by image analysis according to 1.
Or more (preferably 1.40 or more, more preferably 2.0
It can be characterized by being 0 or more).

(1) On the wall of the carbon nanotube in the above transmission electron microscope image, two parallel lines (line 1 and line 2 respectively) with a 3 nm interval are drawn in the wall thickness direction (see below-mentioned figure). 1).

(2) The distance (L) in the thickness direction of the wall from the intersection of the line 1 and the outside of the wall is plotted on the horizontal axis, and the line 1 from the point on the line 1 corresponding to the distance on the horizontal axis. Line 2 on the line perpendicular to
Value (P) that is the sum of the pixel densities of certain pixels before coming into contact with
Is plotted on the vertical axis to obtain a graph of the relationship between the distance (L) and the pixel density integrated value (P) (see FIG. 2).

(3) In the above graph, the average value of the difference between the adjacent maximum value and minimum value of the pixel density integrated value (P) in the region of 20% thickness from the outside of the wall is A, and the outside of the wall From the average value of the difference between the adjacent maximum value and minimum value of the pixel density integrated value (P) in the area of 50 to 100%
And Note that, here, the average value of the difference between the adjacent local maximum value and the local minimum value is the difference (Δ1) between the first local maximum value and the local minimum value adjacent thereto, the local minimum value and the next local maximum value adjacent thereto. It is a value obtained by sequentially calculating the differences between all the maximum values and the minimum values as in the difference (Δ2) ... (Δn), and averaging these differences.

(4) Alternatively, in the above graph, the average value of the difference between the adjacent maximum value and minimum value of the pixel concentration integrated value (P) in the area of 1.5 nm thickness from the outside of the wall is C.
Then, the average value of the difference between the adjacent maximum value and minimum value of the pixel concentration integrated value (P) in the region of thickness 2.0 nm to the inside from the outside of the wall is D.

FIG. 1 is a transmission electron microscope image of carbon nanotubes obtained in Example 4 described later. The magnification of the transmission electron microscope image used for the image analysis of FIG. 1 is 1.6 million times. The magnification of the transmission electron microscope image when using this image analysis method needs to be 1,000,000 times or more at which the graphene sheet can be clearly confirmed. Even if it is less than 1 million times or more than 1 million times, the crystallinity of the carbon nanotube cannot be accurately expressed in an image in which the graphene sheet is unclear.

The number of pixels between the lines 1 and 2 of the transmission electron microscope image used for the image analysis of FIG. 1 is 75, and the distance between the pixels is 0.04 nm. The distance between pixels of the transmission electron microscope image when using this image analysis method is 0.06.
It is preferably nm or less. Distance between pixels is 0.0
In a low-resolution image larger than 6 nm, the crystallinity of carbon nanotube cannot be accurately expressed.

The tip of the carbon nanotube is a region where the carbon nanotube wall has a unique structure,
It is not a region that characterizes the crystallinity of the entire carbon nanotube. Therefore, the region of the carbon nanotube wall used in the above image analysis method needs to be in a region other than the tip portion of the carbon nanotube.

In the case of a carbon nanotube wall having a high degree of crystallinity, the graphene sheet forming the wall develops in a direction perpendicular to the wall thickness direction, and that direction is the same as the above-mentioned pixel concentration integration direction. Therefore, when the pixel densities on the graphene sheet are integrated, the integrated value becomes a large value,
When the pixels between the graphene sheets are integrated, the integrated value becomes a small value.

In the case of a carbon nanotube wall having a high degree of crystallinity, since the arrangement interval of the graphene sheets is about 0.33 nm, the relationship between the distance (L) and the pixel concentration integrated value (P) is a maximum value. And the minimum value is shown periodically, and the difference between the maximum value and the minimum value becomes large. On the other hand, in the case of carbon nanotube walls with low crystallinity, the graphene sheets are not aligned and the length is short, so the maximum and minimum values obtained by applying this image analysis method The difference is small compared to the region where the crystallinity is high. Therefore, by comparing the difference between the maximum value and the minimum value of the graph obtained by the above method, the difference in crystallinity of the carbon nanotube wall can be parameterized and compared.

In the carbon nanotube of the present invention,
The total content of the transition metal, Group 13 element and lanthanoid element is preferably 0.5% by weight or less, more preferably 0.3% by weight or less, and particularly preferably 0.1% by weight or less.

The transition metals include Sc, Ti, V and C.
r, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo,
Ru, Rh, Pd, Ag, Hf, Ta, W, Re, O
s, Ir, Pt, Au, etc., and as the Group 13 element,
B, Al, Ga, In, etc., and the lanthanoid elements include La, Ce, Pr, Nd, Pm, Sm, Eu, G.
d, Tb, Dy, Ho, Er, Tm, Yb, Lu and the like.

Since the total content of the above-mentioned elements is 0.5% by weight or less, the carbon nanotube of the present invention has a wide range of applications in various composite materials, such as an electrically conductive material, a quantum wire device, and a superluminal speed. It can be used for electric elements, ultra-high density magnetic recording media, carbon films, nonlinear optical materials, electric emission materials, electrodes, hydrogen storage materials, and the like.

The method for producing carbon nanotubes of the present invention is not limited as long as it can form the above-mentioned specific structure, but the following solid phase method is recommended.

The first manufacturing method is as follows. That is, resin fine particles that decompose and disappear (hereinafter referred to as “core particles”) are coated with a carbon precursor resin, and have an average particle diameter of 10 to 10.
Particles having a Cv value of 10000 nm and a particle diameter of 30% or less are melt-spun, subjected to an infusibilization treatment as appropriate, and then heated and fired for carbonization treatment.

The average particle diameter of the core particles is appropriately selected depending on the final desired tube diameter in consideration of the thickness of the carbon precursor resin coating, melt spinning conditions, etc., but is preferably 50 to 2000 nm.

The resin that decomposes and disappears by heating means a resin that decomposes and gasifies with increasing temperature under the heat treatment conditions for carbonization described later. That is, any resin may be used as long as its decomposition temperature is lower than the heat treatment temperature for carbonization.

Specific examples of the resin that decomposes and disappears by heating include olefin polymers such as polyethylene, polypropylene and polystyrene; polyesters; diene polymers such as polybutadiene and polyisoprene; polymethyl acrylate, polyethyl acrylate and polypropyl acrylate. Polymers of polyacrylic acid ester and acrylic acid derivative; Polymers of polymethacrylic acid ester and methacrylic acid derivative such as polymethylmethacrylate, polyethylmethacrylate, polypropylmethacrylate; Polymers containing heteroatom molecules such as polyoxymethylene Is mentioned. Among these, a polymer of a methacrylic acid derivative and a polymer of an acrylic acid derivative are preferable because they have similar spinnability when a polymer of acrylonitrile is selected as a carbon precursor resin coating material described later.

As the method for forming the core particles, a polymer solution is used as a raw material, particles are formed by a spray dryer, particles are formed in a high-speed air stream (impact method), monomers are polymerized and chemically grown. Method etc. are mentioned. Among these methods, the method of polymerizing a monomer and chemically growing it is preferable because the particle size and particle properties can be easily controlled and uniform particles can be obtained. Note that it is difficult to control the particle size and particle properties in the method of forming particles by physical treatment or impact.

The polymerization method for forming the core particles may be appropriately selected depending on the kind of the polymer, and for example, solution polymerization method, suspension polymerization method, emulsion polymerization method, precipitation polymerization method, dispersion polymerization method, reverse phase emulsification method. It can be selected from a polymerization method, a microemulsion polymerization method, a miniemulsion polymerization method, a soap-free emulsion polymerization method and the like. The inner diameter and outer diameter of the carbon nanotube can be controlled by appropriately selecting the diameter of the core particle. Therefore, it is preferable to select raw materials and polymerization conditions so that fine and uniform core particles can be obtained.

In the above solution polymerization method, a polymerization degree controlling type solution polymerization method such as living polymerization, coordination polymerization, metallocene polymerization, etc. is preferable. In the emulsion polymerization method, impurity components containing an alkali metal such as K and Na derived from an emulsifier are easily mixed. Therefore, after the core particles are formed, purification treatment such as dialysis is appropriately performed, or ammonium persulfate is used without using an emulsifier. A soap-free emulsion polymerization method using a polymerization initiator such as potassium persulfate is advantageous.

The solvent used in the polymerization is water,
In addition to polar media such as alcohols such as methanol, ethanol and propanol, other organic media such as toluene, xylene, tetrahydrofuran, DMSO and n-methylpyrrolidone can be mentioned. These can also be used in combination. Among these, a polar medium such as water is advantageous from the viewpoint of treatment associated with separation and recovery.

The polymerization temperature, reaction time and monomer concentration may be appropriately selected depending on the monomer raw material used and the polymerization method in accordance with the desired particle shape. For example, using a polar medium such as water, for example, suspension polymerization, emulsion polymerization, precipitation polymerization,
The polymerization temperature in the case of performing soap-free emulsion polymerization is usually 25 ° C. or higher, preferably 40 ° C. or higher, usually 100 ° C. or lower, preferably 90 ° C. or lower, and the polymerization time is usually 5
Min or more, preferably 30 minutes or more, usually 50 hours or less, preferably 20 hours or less, and the monomer concentration in the solvent is usually 0.1% by weight or more, preferably 1% by weight or more, usually 50
It is not more than 20% by weight, preferably not more than 20% by weight, more preferably not more than 15% by weight.

The polymerization temperature in the case of carrying out living polymerization, reverse phase emulsion polymerization or the like using the other organic medium mentioned above is usually 60 ° C. or higher and 120 ° C. or lower, preferably 1 ° C.
The polymerization time is usually 5 minutes or longer, preferably 30 minutes or longer, usually 50 hours or shorter, preferably 20 hours or shorter, and the monomer concentration in the solvent is usually 0.01% by weight.
The above content is preferably 0.1% by weight or more, usually 50% by weight or less, preferably 20% by weight or less, and more preferably 10% by weight or less.

The polymerization initiator is appropriately selected depending on the polymerization method. For example, as the radical initiator, an azo compound (azobisisobutyronitrile or the like), an inorganic peroxide (persulfate such as potassium persulfate or ammonium persulfate), a metal peroxide ((C ₂ H ₅ ) ₂ BOOC ₂ H ₅ , compounds in which the boron atom is substituted with Al or Zn in the compounds on the left), organic peroxides (acyl peroxide such as benzoyl peroxide, t-butyl peroxide, alkyl peroxide such as cumyl peroxide) , Peroxyoxalate-t-butyl and other peroxides, hydroperoxides and the like) and the like.

As the redox initiator, an aqueous initiator (hydrogen peroxide-Fe ²⁺ (Fenton's reagent), persulfate + sulfite, cumene hydroperoxide-amine compound, non-aqueous initiator (benzoyl peroxide) -Dimethylaniline, methyl ethyl ketone peroxide-cobalt naphthenate, etc.).

As the above-mentioned polymerization initiator and redox initiator, it is preferable to use those containing no metal,
Even if it is contained, it is preferably adjusted to be 0.5% by weight or less, preferably 0.1% by weight or less in the carbon nanotube as a product.

As a method for producing core particles, a method of polymerizing methyl methacrylate (MMA) is preferable because uniform core particles can be obtained in good yield. For example, in the case of the soap-free emulsion polymerization method, the polymerization temperature is usually 50 ° C.
Or higher, preferably 60 ° C. or higher, usually 100 ° C. or lower, preferably 90 ° C. or lower, and the monomer concentration in the solvent is usually 0.
1 wt% or more, preferably 1 wt% or more, more preferably 5 wt% or more, usually 20 wt% or less, preferably 15
The weight% or less, the polymerization time is usually 50 minutes or more, preferably 1 hour or more, usually 20 hours or less, preferably 15 hours or less, more preferably 10 hours or less.

Next, the core particles obtained by the above method are coated with a carbon precursor resin so that the average particle size is 10 to 100.
Particles having a Cv value of 00 nm and a particle size of 30% or less are formed. At this time, it is preferable that the carbon precursor resin coat the core particles with a uniform thickness. The average thickness of the carbon precursor resin coating the core particles is appropriately selected depending on the final desired tube diameter, in consideration of the particle diameter of the core particles, the melt spinning conditions described later, and the like.

The average thickness of the carbon precursor resin coating the core particles is usually 10 nm or more, preferably 50 nm or more,
It is usually 10,000 nm or less, preferably 2000 nm or less. The average particle size of the particles coated with the carbon precursor resin is
It is preferably 50 to 2000 nm or less. Cv of particle size
The value is preferably 20% or less.

The average thickness of the above-mentioned carbon precursor resin was determined by dyeing as needed after forming the carbon precursor resin coating, and using a TEM (transmission electron microscope) photograph of the cross section of the microcapsules.
It can be statistically obtained by observing the cross section of the microcapsule in the visual field. The Cv value of the particle size is
It can be determined by obtaining the standard deviation of the particle size from a micrograph of the obtained particles, light scattering measurement, small angle X-ray scattering (SAXS), etc., and dividing by the average particle size (expressed as a percentage).

As the carbon precursor resin, for example, polyvinyl chloride, polyvinyl alcohol, polyacrylonitrile, polyimide, polyamide, phenol resin, furan resin, polyoxadiazole, poly p-phenylene vinylene, polyvinylidene chloride, high liquid crystallinity. Examples include molecules. Of these, resins having a linear structure rather than a three-dimensional structure, such as polyacrylonitrile, polyvinyl chloride, and polyvinyl alcohol, are preferable from the viewpoint of promoting crystal growth. A copolymer resin with a resin monomer that decomposes and disappears by heat can be used as the carbon precursor resin.

As a method for coating the core particles with the carbon precursor resin, a known coating method can be adopted. Since the thickness of the carbon nanotube can be controlled by the thickness of the carbon precursor resin coating, a method capable of coating with a uniform thickness is preferable. As a specific method, a physical method of immersing the core particles in a solution or dispersion of the carbon precursor resin or mechanically mixing the core particles and the carbon precursor resin particles, and a polymerization method A chemical method can be mentioned. Among these, from the viewpoint of forming a uniform coating,
A method of chemically growing by a polymerization method is preferable.

In chemically growing the carbon precursor resin coating on the surface of the core particles by the polymerization method, the polarities of the resins constituting the core particles and the coating are close to each other, and the carbon precursor resin coating in a common poor solvent is performed. It is preferable to carry out the polymerization growth of 1 in order to efficiently grow a uniform coating. Furthermore, it is preferable to select a carbon precursor resin having a higher hydrophilicity than the core particles. From that point,
It is preferable to use a polymer of a methacrylic acid derivative, a polymer of an acrylic acid derivative, polystyrene or the like as core particles, and use polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol or the like as a carbon precursor resin. It is also preferable to use a copolymer of acrylonitrile, vinyl chloride monomer, vinyl acetate, etc. with a methacrylic acid derivative, acrylic acid derivative, styrene etc. as the carbon precursor resin. The core particles do not necessarily have to be separated prior to the formation of the carbon precursor resin coating, and can be used in the state of being dispersed in a solvent for forming the carbon precursor resin coating.

When particles obtained by polymerizing a monomer of methyl methacrylate are used as the core particles, acrylonitrile (AN) and methyl methacrylate (AN) are formed on the surface of the particles as a carbon resin precursor resin under the following conditions. A thin coating can be efficiently obtained by growing MMA) by copolymerization. That is, the polymerization temperature is usually 50 ° C. or higher, preferably 60 ° C. or higher, usually 100 ° C. or lower, preferably 90 ° C. or lower, and the monomer concentration in the solvent is usually 0.0
1% by weight or more, preferably 0.1% by weight or more, more preferably 0.2% by weight or more, usually 20% or less, preferably 15% by weight or less, and the polymerization time is usually 5 minutes or more, preferably 50 minutes or more. It is usually 20 hours or less, preferably 15 hours or less, and more preferably 10 hours or less.

Next, in the present invention, the particles coated with the carbon precursor resin are dried and melt-spun. The spinning method is not particularly limited, and in addition to melt spinning by a usual winding method, a spinning method in which fibers are taken out by a force such as air flow, centrifugal force, static electricity, or the like can be adopted.

By the spinning, the carbon precursor resin is drawn extremely fine in the fiber axis direction. At this time, the outer diameter and wall thickness of the carbon nanotube can be controlled by controlling the stretching ratio. Therefore, in order to obtain homogeneous carbon nanotubes in high yield, it is important to keep the conditions such as fiber diameter and draw ratio constant.

Further, in the present invention, each of the raw material components of the core particles and the carbon precursor resin can be spun into a length of 5 cm or more when melt-spun under the same conditions (actual melt-spinning conditions). It preferably has spinning properties. That is, the outer diameter of the obtained carbon nanotube is 500 nm by measuring the diameter of the carbon nanotube.
It is important to select these raw materials to: As a result, the obtained particles are extremely well stretched in the fiber axis direction to reduce the diameter. The spinning length in a more preferable spinning property is 10 cm or more.

The actual melt spinning conditions are determined in consideration of the spinning characteristics of each raw material component. Specifically, the spinning characteristics of each raw material component are measured from the range of the above-mentioned actual melt spinning conditions (nozzle diameter, spinning speed, spinning temperature, etc.), and each raw material component has the above spinning characteristics (spinning of 5 cm or more). The common range in which the length can be achieved is selected as the actual melt spinning condition.

The melt spinning conditions may be appropriately selected depending on the spinning characteristics of the raw material components and each method. In the case of the winding method, the usual conditions are a nozzle diameter of 0.01 mm or more and 5 mm or less, and a spinning speed. Is 1m / min or more, 50
It is less than 00 m / min. The spinning temperature is 40 ° C or higher, 40
It is about 0 ° C or lower. These spinning conditions may be appropriately determined in consideration of the spinning characteristics of the raw material components described below.

Next, in the present invention, the fibers obtained above are subjected to infusibilization treatment as appropriate. The infusibilizing treatment is not particularly limited, and a general method can be adopted. For example, when a polymer of acrylonitrile is used as the carbon precursor resin, it is 160 to 250 ° C. in air or oxygen.
It may be oxidized before and after. In this case, in a dry air atmosphere at 250 ° C for 5 hours (5 ° C / from room temperature to 150 ° C /
The temperature is raised in 0.5 minutes and the temperature is raised in the range of 150 to 250 ° C. at a rate of 0.5 ° C./minute), or 220 ° C. in a pure oxygen atmosphere.
For 3 hours (from room temperature to 150 ° C, heat up at 5 ° C / min,
The temperature may be raised at a rate of 1 ° C./min between 150 and 220 ° C.).

Next, in the present invention, the infusibilized fiber is carbonized by heating and firing at high temperature. Generally, the carbonization treatment is carried out in an inert atmosphere such as nitrogen and argon at usually 500 to 2500 ° C., but in the present invention, it is usually 500 ° C. to 1500 ° C., preferably 900 ° C. or more and 1200 ° C. or less, usually 0-24
It is held for a time. The temperature rising rate during firing is usually 0.
1 ° C / min or more, preferably 1 ° C / min or more, usually 100 ° C
/ Min or less, preferably 40 ° C / min or less.

The second manufacturing method of the present invention is as follows. That is, the core particles obtained by the first manufacturing method are coated with a carbon precursor resin, and the average particle size is 10 to 10,000.
nm particles, particles having a Cv value of 30% or less of the particle size are dispersed in a matrix resin that decomposes and disappears by heating to obtain a dispersion, and then the obtained dispersion is melt-spun and appropriately infusibilized. After that, it is heated and baked to be carbonized.

The matrix resin means a resin that decomposes and disappears under the heat treatment conditions for carbonization. That is, any polymer may be used as long as it has a decomposition temperature lower than the carbonization temperature. As these matrix resins, specifically, the resins listed above as the resin of the core particles can be used.

The matrix resin and the core particle resin may be the same kind or different kinds of combinations.
The use of the same resin as the core particles is industrially advantageous because the manufacturing process of the carbon nanotube can be simplified.

The dispersion ratio of the particles obtained by coating the surface of the core particles with the carbon precursor resin in the matrix resin is usually 5 parts by weight or more based on 100 parts by weight of the matrix resin.
It is preferably 10 parts by weight or more, more preferably 20 parts by weight or more, usually 1000 parts by weight or less, preferably 500 parts by weight or less, and more preferably 200 parts by weight or less.

As a dispersion method, a known method can be adopted. Specifically, a suspension of particles coated with a carbon precursor resin on the surface of the core particles, a decantation of the particles coated with a carbon precursor resin on the surface of the core particles from the suspension, filtered and separated. It is carried out by dispersing a substance, a centrifuged substance, a dialyzed substance, or a mixture thereof in a matrix resin.

For the melt spinning, the infusibilizing treatment and the carbonizing treatment, which are appropriately performed in the second production method, the same methods as those described in the first production method can be adopted.

In the second production method, each of the raw material components of the core particles, the carbon precursor resin and the matrix resin has a length of 5 cm or more when melt-spun under the same conditions (actual melt-spinning conditions). In addition, it is preferable to have a spinning property capable of spinning, more preferably 10 cm.
That is all.

The third production method of the present invention is as follows: "After the carbon precursor resin is chemically coated on the surface of the resin fine particles which are chemically grown by the polymerization method and decompose and disappear by heating,
A dispersion is obtained by dispersing in a matrix resin that decomposes and disappears by heating, and then the obtained dispersion is melt-spun.
It is characterized in that it is subjected to infusibilization treatment as appropriate, and then heated and fired to be carbonized, which is already mentioned in the above-mentioned production method.

The fourth manufacturing method of the present invention is as follows. That is, after the polymerization of the resin monomer that decomposes and disappears by heating, the component containing the monomer of the carbon precursor resin is charged and polymerized, and subsequently, the resin monomer that decomposes and disappears by heating is charged and polymerized. The fine particles are melt-spun, subjected to infusibilization treatment as appropriate, and then heat-fired to carbonize.

As the resin and carbon precursor resin used in the fourth production method which decompose and disappear by heating, the same resins as those described in the first production method can be used, and the same method is adopted for the polymerization method. it can. Thus, the fine particles obtained by sequentially charging monomers and polymerizing them stepwise are melt-spun, appropriately infusibilized, and then heat-fired to carbonize the present invention. Specific carbon nanotubes can be manufactured. Further, as the method of melt spinning, infusibilization treatment appropriately performed, and carbonization treatment, the same method as the method described in the above-mentioned first manufacturing method can be adopted.

The fifth manufacturing method of the present invention is as follows. That is, after coating the carbon precursor resin on the resin fine particles that decompose and disappear by heating, further coat the resin that decomposes and disappears by heating, and then melt-spin the obtained particles, and after performing infusibilization treatment appropriately. Then, it is heated and baked to be carbonized.

In the fifth manufacturing method, the operation until the carbon precursor resin is coated on the resin fine particles which decompose and disappear by heating can be performed in the same manner as in the case of the first manufacturing method described above. Then, in the method of coating a resin that decomposes and disappears by heating, the resin that can be used for the core particles described in the first manufacturing method can be adopted as the resin that decomposes and disappears by heating. The coating method may be the same as the method for coating the carbon precursor resin described in the first manufacturing method. For the melt spinning, the infusibilizing treatment and the carbonizing treatment, which are appropriately performed, the method described in the first production method can be adopted.

In the above-mentioned production method, the particles in which the surface of the core particles is coated with the carbon precursor resin, the core particles or the resin for the matrix are washed with distilled water or the like before and after the separation and / or the dialysis operation, and then polymerized. It is preferable to perform a treatment for removing impurities such as an initiator.

[0073]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Also, the ratio of B to A (B / A) and D to C as defined herein.
The ratio (D / C) was determined by a method defined in the text using a transmission electron microscope image of carbon nanotubes having a magnification of 1.6 million times and a distance between adjacent pixels of 0.04 nm.

Example 1 In 350 ml of deionized water, 35 ml of MMA monomer and 35 mg of potassium persulfate (hereinafter referred to as KPS) as a radical polymerization initiator were added and mixed, and nitrogen gas was bubbled for 30 minutes. Then, while stirring at 300 rpm, the mixture was stirred at 70 ° C. for 4.5 hours, and then at 80 ° C. for 3 hours.
Reaction was carried out for 0 minutes to obtain a suspension of PMMA core particles.

To 90 ml of the above suspension, 4 ml of acrylonitrile monomer, 5 mg of KPS and 270 ml of deionized water.
ml was added, and nitrogen gas was bubbled for 30 minutes. Then, while stirring at 300 rpm, the mixture was reacted at 70 ° C. for 7.5 hours, and then at 80 ° C. for 30 minutes to react with PMM.
A suspension of particles in which the A core particles were coated with the carbon precursor resin was obtained.

FIG. 3 shows a drawing-substitute SEM (scanning electron microscope) photograph of average particles obtained by freeze-drying a part of the above suspension. By visual inspection of FIG. 3, the average particle size of the particles is 33.
The Cv value of 0 nm and the particle size is about 15%.

As a matrix resin, a suspension of PMMA core particles and a suspension of particles in which PMMA particles were coated with a carbon precursor resin were mixed in a weight ratio of 4: 6. Then, after homogenizing treatment by ultrasonic waves for 30 minutes, it was freeze-dried. The obtained powder was melt-spun at 310 to 320 ° C. to obtain a fiber. The nozzle diameter of the spinning device is 0.
It was 5 mm and the spinning speed was about 10 m / min.

250 ° C. in dry air for the above fibers
For 5 hours (up to 150 ° C at 5 ° C / min, then 2
An infusibilizing treatment was carried out in which the temperature was raised to 50 ° C. at 0.5 ° C./min. After that, the temperature is raised at 5 ° C./min in a nitrogen atmosphere to 10
It was kept at 00 ° C. for 1 hour to carbonize it. As a result, both the core particles and the matrix resin were decomposed and disappeared, and carbon nanotubes were obtained.

The average size of the carbon nanotubes is 15.4 nm in diameter, the diameter of the central cavity is 1.4 nm,
Wall thickness: 7 nm. Figures 4 to 6 show TEM photographs of the obtained carbon nanotubes as substitutes for drawings. These TE
From the M photograph, it was observed that the outer region of the wall of the carbon nanotube had an amorphous structure and the inner region had the crystal structure of the graphene sheet, and no shadow derived from the inclusion of the metal was observed. Further, an image containing amorphous carbon other than carbon nanotubes was also observed.

Example 2 In Example 1, the amount of acrylonitrile added during the polymerization of the carbon precursor resin was 2 ml, and the carbonization temperature was 90%.
A carbon nanotube was produced in the same manner as in Example 1 except that the temperature was 0 ° C. and the time was 30 minutes. The average size of the obtained carbon nanotubes was 10 nm in diameter, the diameter of the central cavity was 2.4 nm, and the wall thickness was about 4 nm.
Fig. 7 TEM for substitute drawing of average carbon nanotube
Show a photo. From this TEM photograph, it was observed that the outer region of the wall of the carbon nanotube has an amorphous structure and the inner region has a crystal structure of the graphene sheet,
No shadow due to the inclusion of metal was observed. Further, an image containing amorphous carbon other than carbon nanotubes was also observed.

Example 3 In 350 ml of deionized water, 35 ml of MMA monomer and 35 mg of KPS as a radical polymerization initiator were added and mixed, and nitrogen gas was bubbled for 30 minutes. Then, it was made to react at 70-80 degreeC for 8 hours, stirring at 300 rpm, and the suspension of PMMA-ized particles was obtained.

To 90 ml of the above suspension, 2 ml of acrylonitrile monomer, 5 mg of KPS and 260 of deionized water were added.
ml was added, and nitrogen gas was bubbled for 30 minutes. Then, while stirring at 300 rpm, 70-80
The reaction was carried out at 8 ° C. for 8 hours to obtain a suspension of particles in which PMMA core particles were coated with the carbon precursor resin.

To 350 ml of the above suspension, 35 ml of M
MA monomer and KPS 5mg and deionized water 350ml
Was added and nitrogen gas was bubbled for 30 minutes. Then, while stirring at 300 rpm, 8 at 70-80 ° C.
A reaction was carried out for a time to obtain a suspension.

FIG. 8 shows a SEM photograph as a drawing substitute of the particles obtained by freeze-drying a part of the above suspension. By visually observing this SEM photograph, the average particle size of the particles was 770 nm, and the C
The v value was about 15%.

After freeze-drying the above particles, the obtained powder was melt-spun at about 300 ° C. in an Ar gas atmosphere to obtain fibers. The nozzle diameter of the spinning device was 0.5 mm, and the spinning speed was about 60 m / min.

The above fiber was heated in pure oxygen at 220 ° C. for 3 hours (up to 150 ° C. at 5 ° C./minute, and then 22
An infusibilizing treatment was carried out in which the temperature was raised to 0 ° C. at 1 ° C./min. Then, the temperature is raised at 5 ° C./min in a nitrogen atmosphere to 1000
It was kept at 30 ° C for 30 minutes for carbonization. As a result, a polymer that decomposed and disappeared by heating was decomposed and disappeared to obtain a carbon nanotube.

The average size of the carbon nanotubes was 11 nm in diameter, the diameter of the central cavity was 1.4 nm, and the wall thickness was 5 nm. A TEM photograph of the obtained carbon nanotubes as a substitute for a drawing is shown in FIG. From this TEM photograph, it was observed that the outer region of the wall of the carbon nanotube had an amorphous structure and the inner region had a crystal structure of the graphene sheet, and no shadow derived from the inclusion of the metal was observed. Further, an image containing amorphous carbon other than carbon nanotubes was also observed.

Example 4 In 350 ml of deionized water, 35 ml of MMA monomer and 35 mg of KPS as a radical polymerization initiator were added and mixed, and nitrogen gas was bubbled for 30 minutes. Then, the mixture was reacted at 70 to 80 ° C. for 8 hours with stirring at 300 rpm to obtain a suspension of PMMA core particles.

In 90 ml of the above suspension, 3 ml of acrylonitrile monomer, 1 ml of methyl methacrylate and K were added.
PS (5 mg) and deionized water (260 ml) were added, and nitrogen gas was bubbled for 30 minutes. After that, 300 rp
After reacting at 70 to 80 ° C. for 8 hours with stirring at m, 24 ml of MMA monomer, 35 mg of KPS and 350 ml of deionized water were added to 350 ml of the suspension, and nitrogen gas was bubbled for 30 minutes. . afterwards,
While stirring at 300 rpm, reaction was carried out at 70 to 80 ° C. for 8 hours to obtain a suspension of fine particles.

After freeze-drying the above suspension, the obtained powder was melt-spun at about 300 ° C. in an Ar gas atmosphere to obtain a fiber. The nozzle diameter of the spinning device was 0.5 mm, and the spinning speed was about 60 m / min.

The above fibers were heated in pure oxygen at 220 ° C. for 4 hours (up to 150 ° C. at 5 ° C./minute, and then 22
After the infusibilizing treatment of holding the temperature up to 0 ° C. at a rate of 1 ° C./minute), the temperature is raised at a rate of 5 ° C./minute in a nitrogen atmosphere and then at 1000 ° C.
It was held for carbonization. As a result, a polymer that decomposed and disappeared by heating was decomposed and disappeared to obtain a carbon nanotube.

The average size of carbon nanotubes is 15 nm in diameter, the diameter of the central cavity is 3 nm, and the wall thickness is 6
was nm. Figures 10 to 13 show TEM photographs of the obtained carbon nanotubes as substitutes for drawings. From these TEM photographs, it was observed that the outer region of the wall of the carbon nanotube had an amorphous structure and the inner region had the crystal structure of the graphene sheet, and no shadow derived from the inclusion of the metal was observed. It was Further, an image containing amorphous carbon other than carbon nanotubes was also observed.

14 and 15 are partial views of FIGS. 10 and 11, respectively. The entire area between two parallel lines drawn on the carbon nanotube wall in FIGS. 14 and 15 at intervals of 3 nm in the wall thickness direction (3 places in each FIG.)
16 and 17 are graphs obtained by performing image analysis by the above method.

Clearly from FIGS. 16 and 17, there is a large difference between the adjacent maximum and minimum values of the pixel concentration integrated values in the inner region of the carbon nanotube wall, and in the outer region the adjacent maximum and minimum values of the pixel concentration integrated values are large. It can be seen that the difference between is small.
This indicates that the crystallinity inside the carbon nanotube wall is high and the crystallinity outside is low.

The results of calculating B / A from FIGS. 16 and 17 are 4.21, 1.45, 1.81, 4.14, 3.
It became 30, 2.73. Both values are greater than 1.20. This indicates that the inner region of the carbon nanotube wall has a higher degree of crystallinity than the outer region.

The results of calculating D / C from FIGS. 16 and 17 are 3.45, 1.41, 2.18 and 3.9.
It became 4, 3.42 and 2.33. Both values are 1.20
Greater than This indicates that the inner region of the carbon nanotube wall has a higher degree of crystallinity than the outer region.

Comparative Example 1 Commercial Hyperion Catalysis Internation by Gas Phase Method
al, Inc. Carbon nanotube "Graphite Fibril
s "(Hyperion Catalysis International, Inc. registered trademark) CC type drawing substitute TEM photographs are shown in Fig. 18 and Fig. 19. From these TEM photographs, shadows derived from the inclusion of metal are shown. It can be seen that many have been observed.

FIG. 20 is a partial view of FIG. It was obtained by performing an image analysis by the above method on the entire region (3 places each) between two parallel lines drawn on the carbon nanotube wall in FIG. 20 at intervals of 3 nm in the wall thickness direction. The graphs are shown in FIG. 21, respectively.

As a result of calculating B / A from FIG. 21, it is 0.6
It became 7, 0.68 and 0.80. Both values are 1.20
Smaller than This indicates that the crystallinity of the inner region of the carbon nanotube wall is not higher than that of the outer region.

Further, as a result of calculating D / C from FIG. 21,
It became 0.76, 0.77, and 0.98. Both values are smaller than 1.20. This indicates that the crystallinity of the inner region of the carbon nanotube wall is not higher than that of the outer region.

FIG. 22 is obtained from FIG. 14, FIG. 15, and FIG.
It is explanatory drawing which extracts the image analysis area | region of each 1 place, and compares the graph obtained according to the said method. The data obtained by extracting from FIG. 14 and FIG. 15, which are the results of Example 4, reveal that the difference between the adjacent maximum value and minimum value of the pixel concentration integrated value in the inner region of the carbon nanotube wall is clearer than that in the outer region. It shows that it is getting larger. On the other hand, the data extracted from FIG. 20 of the comparative example shows that the difference between the adjacent maximum value and minimum value of the pixel concentration integrated values in the inner region of the carbon nanotube wall is not larger than that in the outer region. And in contrast to the above.

[0102]

EFFECTS OF THE INVENTION The carbon nanotube of the present invention is characterized in that the outer region of its wall has an amorphous structure, so that a functional group is easily added to the surface, and the inner region has a crystalline structure, and thus has high electrical conductivity and strength. It is a novel carbon nanotube having Such a carbon nanotube of the present invention utilizes the characteristics thereof to make an electrically conductive material,
It can be used for a quantum wire device, a superluminous electric device, a super high density magnetic recording medium, a carbon film, a non-linear optical material, an electric emission material, an electrode and a hydrogen storage material.

Further, the production method of the present invention is an inexpensive solid phase method, enables high-yield mass production of carbon nanotubes, and is easy to obtain properties such as outer diameter and thickness of carbon nanotubes. This is an industrially advantageous method that can be controlled and that the obtained carbon nanotube does not contain a metal component.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing regions used for image analysis in a transmission electron microscope image of carbon nanotubes.

FIG. 2 is a schematic explanatory diagram showing an image analysis method for evaluating the crystallinity of the wall of the carbon nanotube.

FIG. 3 is a drawing-substitute SEM (scanning electron microscope) photograph of particles obtained by coating the PMMA core particles obtained in Example 1 with a carbon precursor resin.

FIG. 4 is a drawing-substituting TEM photograph of the carbon nanotubes obtained in Example 1.

5 is a drawing-substituting TEM photograph of carbon nanotubes obtained in Example 1. FIG.

6 is a drawing-substituting TEM photograph of the carbon nanotubes obtained in Example 1. FIG.

7 is a drawing-substitute TEM photograph of the carbon nanotubes obtained in Example 2. FIG.

8 is a drawing-substitute SEM photograph of particles obtained by freeze-drying a part of the suspension obtained in Example 3. FIG.

9 is a drawing-substituting TEM photograph of carbon nanotubes obtained in Example 3. FIG.

10 is a drawing-substituting TEM photograph of carbon nanotubes obtained in Example 4. FIG.

11 is a drawing-substituting TEM photograph of the carbon nanotubes obtained in Example 4. FIG.

FIG. 12 is a drawing-substituting TEM photograph of the carbon nanotubes obtained in Example 4.

13 is a drawing-substituting TEM photograph of carbon nanotubes obtained in Example 4. FIG.

FIG. 14 is an explanatory view showing a region used for image analysis in a TEM photograph of the carbon nanotube obtained in Example 4.

FIG. 15 is an explanatory diagram showing a region used for image analysis in a TEM photograph of the carbon nanotube obtained in Example 4.

16 is a graph obtained from image analysis of the region of FIG.

FIG. 17 is a graph obtained from image analysis of the region of FIG.

FIG. 18 is a drawing-substitute TEM photograph of the carbon nanotube obtained in Comparative Example 1.

19 is a drawing-substitute TEM photograph of carbon nanotubes obtained in Comparative Example 1. FIG.

20 is an explanatory view showing a region used for image analysis in a TEM photograph of the carbon nanotube obtained in Comparative Example 1. FIG.

FIG. 21 is a graph obtained from image analysis of the region of FIG.

22 is an explanatory diagram comparing graphs obtained from image analysis of Example 4 and Comparative Example 1. FIG.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4G146 AA11 AA16 AB08 AC03A                       AC03B AD16 BA04 BA13                       BB12 BB15 BC03 BC07 BC33A                       BC33B BC34A BC34B                 4L037 CS03 FA02 FA04 FA05 FA20                       PA31 PA53 PC11 PS02 PS12                       UA04

Claims (17)

[Claims] 1. An outer diameter of 500 nm or less and a length of 50 nm
A carbon nanotube as described above, wherein the outer region of the wall has an amorphous structure and the inner region has a crystalline structure. 2. A transmission electron microscope image of carbon nanotubes, which has a magnification of 1,000,000 times or more and a distance between adjacent pixels is 0.06 nm or less, and is obtained by image analysis according to the following procedure: The carbon nanotube according to claim 1, wherein a ratio of B to A (B / A) defined below is 1.20 or more. (1) Draw two parallel lines (line 1 and line 2, respectively) at intervals of 3 nm in the wall thickness direction on the wall of the carbon nanotube in the transmission electron microscope image. (2) The distance (L) in the thickness direction of the wall from the point where the line 1 intersects the outside of the wall is plotted on the horizontal axis, and the point on the line 1 corresponding to the distance on the horizontal axis is perpendicular to the line 1. A value (P) obtained by integrating the pixel densities of pixels existing on the line until the line 2 is in contact with the line is plotted on the vertical axis to obtain a graph of the relationship between the distance (L) and the pixel density integrated value (P). (3) In the above graph, the average value of the difference between the adjacent maximum value and minimum value of the pixel concentration integrated value (P) in the region of 20% thickness from the outside of the wall is A, and 50 to 50% from the outside of the wall.
Let B be the average value of the difference between the adjacent maximum value and minimum value of the pixel density integrated value (P) in the area of 100% thickness. 3. A transmission electron microscope image of carbon nanotubes, which has a magnification of 1,000,000 times or more and a distance between adjacent pixels is 0.06 nm or less, and is obtained by image analysis according to the following procedure: The carbon nanotube according to claim 1, wherein a ratio of D to C (D / C) defined below is 1.20 or more. (1) Draw two parallel lines (line 1 and line 2, respectively) at intervals of 3 nm in the wall thickness direction on the wall of the carbon nanotube in the transmission electron microscope image. (2) The distance (L) in the thickness direction of the wall from the point where the line 1 intersects the outside of the wall is plotted on the horizontal axis, and the point on the line 1 corresponding to the distance on the horizontal axis is perpendicular to the line 1. A value (P) obtained by integrating the pixel densities of pixels existing on the line until the line 2 is in contact with the line is plotted on the vertical axis to obtain a graph of the relationship between the distance (L) and the pixel density integrated value (P). (3) In the above graph, 1.5 nm from the outside of the wall
The average value of the difference between the adjacent maximum value and minimum value of the pixel density integrated value (P) in the thickness area of is defined as C, and the pixel density integrated value in the area of thickness 2.0 nm to the inside from the outside of the wall ( The average value of the differences between the adjacent maximum value and minimum value of P) is defined as D. 4. The total content of the transition metal, the 13th group element and the lanthanoid element is 0.5% by weight or less.
4. The carbon nanotube according to any one of 3 to 3. 5. The carbon nanotube according to claim 1, which is obtained by a solid phase method. 6. A carbon precursor resin is coated on resin fine particles which decompose and disappear by heating, and have an average particle diameter of 10 to 10,000.
nm, and particles having a Cv value of 30% or less are melt-spun,
A method for producing a carbon nanotube, which comprises performing an infusibilization treatment as appropriate and then heating and firing to carry out a carbonization treatment. 7. An average particle diameter of 10 to 10000, which is obtained by coating resin precursor particles which decompose and disappear by heating with a carbon precursor resin.
nm particles, particles having a Cv value of 30% or less of the particle size are dispersed in a matrix resin that decomposes and disappears by heating to obtain a dispersion, and the obtained dispersion is melt-spun and appropriately infusibilized. After that, a method for producing carbon nanotubes, characterized by comprising heating and firing to carry out carbonization treatment. 8. The resin fine particles which decompose and disappear by heating,
The manufacturing method according to claim 6 or 7, which is formed by chemically growing by a polymerization method. 9. The production method according to claim 6, wherein the particles coated with the carbon precursor resin are formed by chemically coating the resin fine particles with the carbon precursor resin. 10. Particles obtained by coating resin particles which decompose and disappear by heating with a carbon precursor resin, are charged with a monomer of a carbon precursor resin after polymerization of a monomer of a resin which decomposes and disappears by heating, and chemically react with the carbon precursor. The manufacturing method according to claim 6 or 7, which is obtained by coating a body resin. 11. The production method according to claim 6, wherein the carbonization treatment by heating and firing after melt spinning is performed at a temperature of 1500 ° C. or lower. 12. A carbon precursor resin is chemically coated on the surface of resin fine particles which are chemically grown by a polymerization method and decompose and disappear by heating, and then dispersed in a matrix resin which decomposes and disappears by heating. To obtain a dispersion, and then melt-spin the obtained dispersion and appropriately infusibilize it,
A method for producing a carbon nanotube, which comprises heating and firing to perform carbonization treatment. 13. The production method according to claim 12, wherein the carbonization treatment by heating and firing after melt spinning is performed at a temperature of 1500 ° C. or lower. 14. Polymerization of a monomer of a resin which decomposes and disappears by heating, followed by charging a component containing a monomer of a carbon precursor resin and polymerization, and then charging and polymerization of a monomer of a resin which decomposes and disappears by heating. A method for producing carbon nanotubes, which comprises melt-spinning the fine particles obtained as described above, appropriately infusibilizing treatment, and then heating and firing to carbonize. 15. The production method according to claim 14, wherein the carbonization treatment by heating and firing after melt spinning is performed at a temperature of 1500 ° C. or lower. 16. A resin fine particle which decomposes and disappears by heating is coated with a carbon precursor resin, and then a resin which decomposes and disappears by heating is further coated, and then the obtained particles are melt-spun and appropriately infusibilized. A method for producing carbon nanotubes, characterized by comprising performing heating and baking to carry out carbonization treatment. 17. The production method according to claim 16, wherein the carbonization treatment by heating and firing after melt spinning is performed at a temperature of 1500 ° C. or lower.