WO2014084042A1 - Complex containing double-walled carbon nanotubes - Google Patents

Complex containing double-walled carbon nanotubes Download PDF

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Publication number
WO2014084042A1
WO2014084042A1 PCT/JP2013/080607 JP2013080607W WO2014084042A1 WO 2014084042 A1 WO2014084042 A1 WO 2014084042A1 JP 2013080607 W JP2013080607 W JP 2013080607W WO 2014084042 A1 WO2014084042 A1 WO 2014084042A1
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Prior art keywords
carbon nanotube
double
walled carbon
carbon nanotubes
resin
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PCT/JP2013/080607
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French (fr)
Japanese (ja)
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史郎 本田
佐藤　謙一
秀和 西野
真史 須藤
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東レ株式会社
ザ・ユニバーシティ・オブ・マンチェスター
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Priority to JP2013555673A priority Critical patent/JPWO2014084042A1/en
Publication of WO2014084042A1 publication Critical patent/WO2014084042A1/en

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    • 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
    • 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
    • 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
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/16—Preparation
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/04—Carbon
    • C08K3/041—Carbon nanotubes
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2202/00—Structure or properties of carbon nanotubes
    • C01B2202/04—Nanotubes with a specific amount of walls
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/011—Nanostructured additives

Definitions

  • the present invention relates to a composite containing a double-walled carbon nanotube.
  • a carbon nanotube is a substance having a structure in which a graphite sheet having a hexagonal network of carbon atoms arranged in a cylindrical shape is wound.
  • a single-walled carbon nanotube is a single-walled carbon nanotube, and a multi-walled carbon is wound in multiple layers. It is called a nanotube.
  • multi-walled carbon nanotubes those wound in two layers are called double-walled carbon nanotubes.
  • Carbon nanotubes have excellent conductivity and high mechanical strength, and are expected to be used as conductive materials and reinforcing materials.
  • the present invention has been made in view of the above, and an object of the present invention is to provide a composite having a high affinity between a double-walled carbon nanotube and a resin and a high mechanical strength.
  • a double-walled carbon nanotube-containing composite includes a double-walled carbon nanotube comprising an inner-layer side carbon nanotube and an outer-layer side carbon nanotube, and a resin
  • a ratio of the slope of the straight line derived from the inner-wall-side carbon nanotube to the slope of the straight line derived from the nanotube is from 0.5 to 1.5.
  • the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the double-walled carbon nanotube is modified with a functional group containing oxygen.
  • the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the functional group is a hydroxyl group or a carboxyl group.
  • the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above-mentioned invention, a ratio of oxygen atoms to carbon atoms in the double-walled carbon nanotube is 0.1 at% or more and 20 at% or less. To do.
  • the double-walled carbon nanotube-containing composite according to the present invention is the value of the ratio of the G-band height to the D-band height when the double-walled carbon nanotube is subjected to Raman spectroscopic analysis at a wavelength of 633 nm. Is 20 or more.
  • the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the resin is a thermosetting resin.
  • the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the resin is an epoxy resin.
  • the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the double-walled carbon nanotube is contained in an amount of 0.001 wt% to 10 wt% with respect to the resin. To do.
  • double-walled carbon nanotube-containing composite of the present invention in the above invention, the absolute value of the slope of the line from the outer side carbon nanotubes, is 10 cm -1 /% or more 50 cm -1 /% or less It is characterized by that.
  • the affinity between the double-walled carbon nanotube and the resin is high, and furthermore, the inner layer and the outer layer of the double-walled carbon nanotube propagate stress.
  • a composite exhibiting good mechanical properties can be obtained.
  • FIG. 1 is a diagram for explaining Raman spectroscopic analysis for a double-walled carbon nanotube-containing composite according to an embodiment of the present invention.
  • FIG. 2 is a schematic diagram showing a configuration example of a carbon nanotube production apparatus for producing a carbon nanotube of a double-walled carbon nanotube-containing composite according to an embodiment of the present invention.
  • FIG. 3 is a graph showing the relationship between strain and G ′ band shift in carbon nanotubes of a double-walled carbon nanotube-containing composite according to an example of the present invention.
  • FIG. 4 is a graph showing the relationship between strain and G ′ band shift in carbon nanotubes of a double-walled carbon nanotube-containing composite according to an example of the present invention.
  • FIG. 1 is a diagram for explaining Raman spectroscopic analysis for a double-walled carbon nanotube-containing composite according to an embodiment of the present invention.
  • FIG. 2 is a schematic diagram showing a configuration example of a carbon nanotube production apparatus for producing a carbon nanotube
  • FIG. 5 is a graph showing the relationship between strain and G ′ band shift in carbon nanotubes of a double-walled carbon nanotube-containing composite according to an example of the present invention.
  • FIG. 6 is a graph showing the relationship between strain and G ′ band shift in a carbon nanotube of a double-walled carbon nanotube-containing composite according to an example of the present invention.
  • FIG. 7 is a graph showing the relationship between strain and G ′ band shift in a carbon nanotube of a double-walled carbon nanotube-containing composite according to an example of the present invention.
  • FIG. 8 is a graph showing the relationship between strain and G ′ band shift in a carbon nanotube of a double-walled carbon nanotube-containing composite according to an example of the present invention.
  • the double-walled carbon nanotube-containing composite according to the present invention includes a double-walled carbon nanotube in which two carbon nanotubes having different diameters (inner-wall side carbon nanotube and outer-layer side carbon nanotube) are concentrically overlapped, and a resin. Is the body.
  • the double-walled carbon nanotube is a graph showing the relationship between the distortion of the composite and the G ′ band shift obtained when a Raman spectroscopic analysis is applied to the composite.
  • the ratio of the slope of the straight line derived from the inner-layer-side carbon nanotube (the slope of the inner layer / the slope of the outer layer) is 0.5 or more and 1.5 or less.
  • the carbon nanotubes have a shape in which one surface of graphite is wound into a cylindrical shape, and a single-walled carbon nanotube is a single-walled carbon nanotube and a multi-walled carbon nanotube is a single-walled carbon nanotube.
  • multi-walled carbon nanotubes those wound in two layers are called double-walled carbon nanotubes.
  • the double-walled carbon nanotube used in the present invention means a total of a plurality of double-walled carbon nanotubes, and the form of existence thereof is not particularly limited, and each is independent or bundled or entangled. It may exist in the form or a mixed form thereof.
  • the impurity for example, catalyst
  • the thing comprised substantially by carbon is shown.
  • the thing of various diameter may be contained.
  • the morphology of carbon nanotubes can be examined with a high-resolution transmission electron microscope.
  • the graphite layer is preferred so that it can be seen straight and clearly in a transmission electron microscope, but the graphite layer may be disordered.
  • the carbon nanotubes used in the present invention may contain carbon nanotubes having various numbers of layers, but are mainly composed of double-walled carbon nanotubes.
  • the main component means that 50 or more (half or more) of the 100 carbon nanotubes are double-walled carbon nanotubes when observed with a transmission electron microscope. Furthermore, it is preferable that 70 or more of 100 carbon nanotubes are double-walled carbon nanotubes.
  • the number here refers to the evaluation of the number of double-walled carbon nanotubes by observing 100 arbitrary carbon nanotubes contained in the aggregate of carbon nanotubes.
  • the number of layers and the number of the arbitrary carbon nanotubes can be counted by, for example, observing with a transmission electron microscope at a magnification of 400,000, and in a visual field in which 10% or more of the visual field area is a carbon nanotube in a visual field of 75 nm square.
  • the number of layers is evaluated for 100 carbon nanotubes arbitrarily extracted from. When 100 lines cannot be measured in one field of view, measurement is performed from a plurality of fields until 100 lines are obtained. At this time, one carbon nanotube is counted as one if a part of the carbon nanotube is visible in the field of view, and both ends are not necessarily visible. In addition, even if it is recognized as two in the field of view, it may be connected outside the field of view and become one, but in that case, it is counted as two.
  • the carbon nanotubes used in the present invention are preferably those having an average outer diameter in the range of 1.0 nm to 3.0 nm.
  • the average value of the outer diameter was observed with the transmission electron microscope at a magnification of 400,000, and 100 pieces arbitrarily extracted from a field where 10% or more of the field area was a carbon nanotube in a field of view of 75 nm square. It is an arithmetic mean value when a sample is observed by the same method as that for evaluating the number of layers of carbon nanotubes and the outer diameter of the carbon nanotubes is measured.
  • the double-walled carbon nanotube used in the present invention is modified with a functional group containing oxygen.
  • the functional group containing oxygen includes a hydroxyl group, a carboxyl group, a carbonyl group, an ether group, and the like, but is not particularly limited as long as it contains oxygen. Among these, a hydroxyl group and a carboxyl group are preferable.
  • XPS X-ray photoelectron spectroscopy
  • the double-walled carbon nanotube of the present invention has a functional group containing oxygen as described above, and the ratio of the oxygen atom to the carbon atom in the double-walled carbon nanotube is 0.1 at% (atomic%) or more and 20 at%. % Or less.
  • a ratio of oxygen atoms to carbon atoms can be evaluated by using surface composition analysis of X-ray photoelectron spectroscopy (XPS).
  • XPS X-ray photoelectron spectroscopy
  • the ratio of oxygen atoms to carbon atoms is 0.1 at% or more and 20 at% or less, and the carbon nanotube assembly exhibiting excellent conductivity Since it becomes a body, it is preferable.
  • the ratio of oxygen atoms to carbon atoms is 1 at% or more and 15 at% or less.
  • the carbon nanotubes used in the present invention preferably have a ratio of the G band height to the D band height (G / D ratio) by Raman spectroscopy of 20 or more. More preferably, it is 40 or more and 200 or less, More preferably, it is 50 or more and 150 or less.
  • the G / D ratio is a value when carbon nanotubes are evaluated by Raman spectroscopy.
  • a microscopic laser Raman spectrophotometer analyzer JASCO NRS2100 manufactured by JASCO Corporation
  • the laser wavelength used in the Raman spectroscopic analysis method is 633 nm.
  • the Raman shift observed in the vicinity of 1590 cm ⁇ 1 in the Raman spectrum obtained by Raman spectroscopy is called a graphite-derived G band
  • the Raman shift observed in the vicinity of 1350 cm ⁇ 1 is derived from defects in amorphous carbon or graphite. Called the D band.
  • a carbon nanotube having a higher height ratio of G band and D band and a higher G / D ratio indicates a higher degree of graphitization and higher quality.
  • solid Raman spectroscopy such as carbon nanotubes may vary depending on sampling. Therefore, at least three places and another place are subjected to Raman spectroscopic analysis, and an arithmetic average thereof is taken.
  • a G / D ratio of 20 or more indicates a considerably high quality carbon nanotube.
  • the G / D ratio is 20 or less, the original double-walled carbon nanotubes are too low in graphite and the stress of the inner layer and the outer layer does not propagate well.
  • the resin used in the present invention may be either a thermosetting resin or a thermoplastic resin. Preferably, it is a thermosetting resin.
  • thermosetting resin is not particularly limited, and any thermosetting resin can be suitably used. Specifically, unsaturated polyester resins, vinyl ester resins, epoxy resins, phenol resins, urea resins, melamine resins, polyimides, copolymers thereof, modified products, and resins obtained by blending two or more types are used. be able to. Among these, an epoxy resin having an excellent balance of heat resistance, mechanical properties, and adhesiveness can be preferably used.
  • the epoxy resin is not particularly limited, and any epoxy resin can be suitably used. Specifically, it is obtained by oxidizing a glycidyl ether obtained from polyol, a glycidyl amine obtained from an amine having a plurality of active hydrogens, a glycidyl ester obtained from a polycarboxylic acid, or a compound having a plurality of double bonds in the molecule. Polyepoxides that can be used are used.
  • glycidyl ether examples include the following. First, bisphenol A type epoxy resin obtained from bisphenol A, bisphenol F type epoxy resin obtained from bisphenol F, bisphenol S type epoxy resin obtained from bisphenol S, tetrabromobisphenol A type epoxy resin obtained from tetrabromobisphenol A, etc. Bisphenol type epoxy resin.
  • bisphenol F type epoxy resins include “Epicoat” 806, “Epicoat” 807, “Epicoat” E4002P, “Epicoat” E4003P, “Epicoat” E4004P, “Epicoat” E4007P, “Epicoat” E4009P, “Epicoat” E4010P (Made by Japan Epoxy Resin Co., Ltd.), “Epiclon” 830 (Dainippon Ink Chemical Co., Ltd.), “Epototo” YDF-2001, “Epototo” YDF-2004 (above, manufactured by Toto Kasei Co., Ltd.) Can be mentioned.
  • bisphenol S-type epoxy resins include “Denacol (registered trademark, the same shall apply hereinafter)” EX-251 (manufactured by Nagase Kasei Kogyo Co., Ltd.) and “Epiclon” EXA-1514 (manufactured by Dainippon Ink & Chemicals, Inc.). Can be mentioned.
  • tetrabromobisphenol A type epoxy resins include “Epicoat” 5050 (manufactured by Japan Epoxy Resin Co., Ltd.), “Epicron” 152 (manufactured by Dainippon Ink & Chemicals, Inc.), and “Sumiepoxy” ESB-400T (Sumitomo Chemical). And “Epototo” YBD-360 (manufactured by Toto Kasei Co., Ltd.).
  • novolak type epoxy resins which are glycidyl ethers of novolac obtained from phenol derivatives such as phenol, alkylphenol and halogenated phenol, are “Epicoat” 152, “Epicoat” 154, “Epicoat” 157 (above, Japan).
  • Epoxy Resin Co., Ltd. Epoxy Resin Co., Ltd.
  • DER 438 Down Chemical Co., Ltd.
  • Aldite registered trademark, the same applies hereinafter
  • EPN1138 BASF Corp.
  • Araldite EPN1139
  • BREN-105 BREN-105
  • glycidylamine examples include diglycidylaniline, “Sumiepoxy” ELM434 (manufactured by Sumitomo Chemical Co., Ltd.), which is tetraglycidyldiaminodiphenylmethane, and TETRAD (registered trademark, the same applies hereinafter) —tetraglycidyl-m-xylylenediamine— X (manufactured by Mitsubishi Gas Chemical Co., Inc.) can be used, and the resin can be used within a range that does not significantly impair the elongation of the resin.
  • epoxy resins having both glycidyl ether and glycidyl amine structures “Sumiepoxy” ELM120 (manufactured by Sumitomo Chemical Co., Ltd.), which is triglycidyl-m-aminophenol, and “Araldite, which is triglycidyl-p-aminophenol” "MY0510 (manufactured by Ciba-Geigy Corporation) can be mentioned, and it can be used within a range that does not significantly impair the elongation of the resin.
  • glycidyl ester examples include phthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, and dimer acid diglycidyl ester.
  • triglycidyl isocyanurate can be mentioned as an epoxy resin having a glycidyl group other than these.
  • Examples of the epoxy resin obtained by oxidizing a compound having a plurality of double bonds in the molecule include epoxy resins having an epoxycyclohexane ring. Specific examples thereof include ERL-4206 and ERL-4221 of Union Carbide. , ERL-4234, and the like. Furthermore, epoxidized soybean oil can also be mentioned.
  • epoxy resins it is preferable to include one or more epoxy resins having at least one skeleton selected from biphenyl, naphthalene, fluorene, dicyclopentadiene, and an oxazolidone ring.
  • the mechanical properties are remarkably improved by the synergistic effect with the carbon nanofibers, and the heat resistance of the cured resin can also be improved.
  • Examples of commercially available epoxy resins having a biphenyl skeleton include “Epicoat” YX4000, YX4000H, YL6121 (above, Japan Epoxy Resin Co., Ltd.), NC3000, NC3000H (above, Nippon Kayaku Co., Ltd.). it can.
  • epoxy resins having a naphthalene skeleton include “Epiclon” HP4032, HP4032D, H4032H, EXA4750, EXA4700, EXA4701 (above, manufactured by Dainippon Ink Industries, Ltd.), NC7000L, NC7300L (above, manufactured by Nippon Kayaku Co., Ltd.) ) And the like.
  • epoxy resins having a fluorene skeleton include “Epon (registered trademark, the same shall apply hereinafter)”, HPT resin 1079 (manufactured by Shell), “Ogsol (registered trademark, same shall apply hereinafter)” PG, EG (hereinafter referred to as Nagase ChemteX) And the like).
  • epoxy resins having a dicyclopentadiene skeleton include “Epiclon” HP7200L, HP7200, HP7200H, HP7200HH (above, manufactured by Dainippon Ink & Chemicals, Inc.), XD-1000-L, XD-1000-2L (above , Nippon Kayaku Co., Ltd.), “Tactix (registered trademark, the same applies hereinafter)” 556 (manufactured by Huntsman), and the like.
  • Examples of commercially available epoxy resins having an oxazolidone ring skeleton include “Araldite” AER4152, XAC4151, and the like, manufactured by Asahi Kasei Epoxy Corporation.
  • a curing agent may be used.
  • Curing agents bring about a curing reaction in the presence of thermosetting resins and include not only general curing agents but also initiators, catalysts, curing accelerators, curing aids, and combinations thereof. But you can.
  • the curing agent includes activities such as 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, m-phenylenediamine, and m-xylylenediamine.
  • Tertiary amines such as phenol and 1-substituted imidazole that do not have active hydrogen, dicyandiamide, tetramethylguanidine, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic acid Carboxy
  • curing agents can be combined with a curing aid as appropriate in order to increase the curing activity.
  • Preferred examples include dicyandiamide, 3-phenyl-1,1-dimethylurea, 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU), 3- (3-chloro-4-methylphenyl).
  • DCMU 3-(,4-dichlorophenyl) -1,1-dimethylurea
  • DCMU 3- (3-chloro-4-methylphenyl).
  • urea derivatives such as 1,1-dimethylurea and 2,4-bis (3,3-dimethylureido) toluene
  • tertiary amines on carboxylic anhydrides and novolac resins Examples of combinations as agents are given.
  • the compound used as a curing aid is preferably a compound having the ability to cure an epoxy resin alone.
  • thermoplastic resin is not particularly limited, and any thermoplastic resin can be suitably used. Specifically, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl acetate resin, acrylonitrile-butadiene-styrene (ABS) resin, poly (methyl methacrylate) resin, polyamide resin, polycarbonate resin, polybutylene terephthalate resin, polyethylene terephthalate resin, Polyphenylene sulfide resin, polyether ether ketone resin, polyimide resin, polyamideimide resin, polyvinyl alcohol resin and the like can be used.
  • ABS acrylonitrile-butadiene-styrene
  • ABS acrylonitrile-butadiene-styrene
  • poly (methyl methacrylate) resin polyamide resin
  • polycarbonate resin polybutylene terephthalate resin
  • polyethylene terephthalate resin polyethylene terephthalate resin
  • Polyphenylene sulfide resin polyether
  • the double-walled carbon nanotube-containing composite of the present invention is a composite containing 0.001 wt% (wt%) to 10 wt% of double-walled carbon nanotubes with respect to such a resin. Preferably, it is contained at 0.005 wt% or more and 5 wt% or less. Thereby, the resin characteristic of a double-walled carbon nanotube containing composite can be improved suitably.
  • FIG. 1 is a diagram for explaining Raman spectroscopic analysis for a double-walled carbon nanotube-containing composite according to an embodiment of the present invention.
  • the double-walled carbon nanotube-containing composite is subjected to Raman spectroscopic analysis with a predetermined load applied, and a graph showing the relationship between strain and G ′ band shift is obtained.
  • the G ′ band shift with respect to the distortion is acquired by performing the following operation.
  • the composite 1 of the double-walled carbon nanotube and the resin is fixed on the base 10 and stress is applied to the base 10 to distort the composite 1 (see FIG. 1).
  • the stress applied to the base material 10 is a direction in which each surface is pressed from the front surface (upper surface in the figure) and the back surface (lower surface in the figure) in the sheet-like base material 10, and the pressing position on the back surface side is These are applied so as to be located in the center portion from the pressurizing position on the surface side.
  • Due to the distortion of the base material 10, the composite 1 is distorted in an arc shape having a convex surface side.
  • the strain (ratio) at this time is measured with a strain gauge and plotted on the horizontal axis of the graph.
  • the Raman spectroscopic analysis is performed using a laser having a wavelength of 514 nm or 633 nm in a state where the composite 1 is distorted.
  • scattered light from the complex 1 corresponding to the irradiated laser is detected.
  • a G ′ band derived from a double-walled carbon nanotube appears around 2600 cm ⁇ 1 .
  • the G ′ band derived from the inner layer side carbon nanotube is detected in the vicinity of 2590 cm ⁇ 1
  • the G ′ band derived from the outer layer side carbon nanotube is detected in the vicinity of 2630 cm ⁇ 1 .
  • the strain is plotted on the horizontal axis as the pressing rate (Strain (%)), and the G ′ band shift of each of the inner layer and the outer layer is expressed by (G′ ⁇ Band frequency (cm -1 )) is plotted on the vertical axis.
  • the composite containing a double-walled carbon nanotube according to the present invention has a G ′ band shift (plot) with respect to the tensile strain when the graph is prepared in a tensile strain range of 0% to 0.4%.
  • Each of the side carbon nanotubes is located near the approximate straight line.
  • the method of producing the approximate straight line is preferably the least square method.
  • the respective inclinations (cm ⁇ 1 /%) can be obtained. Using this slope value, when the ratio of the slope of the inner carbon nanotube to the slope of the outer carbon nanotube (the slope of the inner layer / the slope of the outer layer) was determined, the composite according to the present invention was 0.5 It is 1.5 or less.
  • the value of the inner layer inclination / outer layer inclination is 0.8 or more and 1.2 or less.
  • the value of the inclination of the inner layer / the inclination of the outer layer is not less than 0.5 and not more than 1.5, indicating that the stress between the inner layer and the outer layer propagates in the double-walled carbon nanotube.
  • the same G ′ band shift occurs, and this inclination becomes nearly parallel. If this inclination exceeds the specified range, it indicates that the force applied to the outer layer is not propagated to the inner layer.
  • the outer layer of the double-walled carbon nanotube exhibits affinity with the resin, and the externally applied force propagates stress between the resin, the outer layer, and the inner layer, thereby demonstrating the high mechanical strength of the very high-quality carbon nanotube of the inner layer itself. Therefore, it exhibits a very high mechanical strength as a composite.
  • the absolute value of the inclination derived from the outer layer is preferably 10 cm ⁇ 1 /% to 50 cm ⁇ 1 /%, and preferably 15 cm ⁇ 1 /% to 30 cm ⁇ 1. /% Or less is more preferable.
  • the inclination within the specified range means that in the double-walled carbon nanotube-containing composite, the stress propagates between the matrix resin and the outer layer of the double-walled carbon nanotube, and the elastic modulus of the double-walled carbon nanotube is high. Indicates.
  • the method for producing a double-walled carbon nanotube preferably used in the present invention is produced, for example, as follows.
  • a fluidized bed made of powdered catalyst with iron supported on magnesia is formed on the entire horizontal cross-sectional direction of the reactor, and methane is circulated in the vertical direction in the reactor. Is obtained by contacting the catalyst at 500 to 1200 ° C. with the catalyst to produce carbon nanotubes, and then purifying the obtained carbon nanotubes.
  • magnesia which is a carrier
  • magnesia a commercially available product may be used, or a synthesized product may be used.
  • magnesium metal is heated in air, magnesium hydroxide is heated to 850 ° C. or higher, or magnesium carbonate 3MgCO 3 .Mg (OH) 2 .3H 2 O is heated to 950 ° C. or higher. There are ways to do it.
  • magnesia light magnesia is preferable.
  • Light magnesia is magnesia having a low bulk density, specifically 0.20 g / mL or less, preferably 0.05 to 0.16 (g / mL). It is preferable from the point.
  • Bulk density is the mass of powder per unit bulk volume. The bulk density measurement method is shown below. The bulk density of the powder may be affected by the temperature and humidity at the time of measurement. The bulk density referred to here is a value measured at a temperature of 20 ⁇ 10 ° C. and a humidity of 60 ⁇ 10%. For the measurement, a 50 mL graduated cylinder is used as a measurement container, and the powder is added so as to occupy a predetermined volume while tapping the bottom of the graduated cylinder.
  • the iron carried on the carrier is not always in a zero-valent state. Although it can be estimated that the metal is in a zero-valent state during the reaction, it may be a compound containing iron or an iron species.
  • organic salts or inorganic salts such as iron formate, iron acetate, iron trifluoroacetate, iron iron citrate, iron nitrate, iron sulfate, and iron halide, complex salts such as ethylenediaminetetraacetic acid complex and acetylacetonate complex, etc. Used.
  • Iron is preferably fine particles. The particle diameter of the fine particles is preferably 0.5 to 10 nm. When iron is a fine particle, a carbon nanotube with a small outer diameter is likely to be generated.
  • the method for producing the carbon nanotube production catalyst is not particularly limited.
  • magnesia is impregnated in a non-aqueous solution (for example, a methanol solution) or an aqueous solution in which a metal salt of iron is dissolved, sufficiently dispersed and mixed, and then dried. Thereafter, it may be heated at a high temperature (100 ° C. to 600 ° C.) in the atmosphere or in an inert gas such as nitrogen, argon or helium or in vacuum (impregnation method).
  • a carrier such as magnesia is impregnated in an aqueous solution in which an iron metal salt is dissolved, sufficiently dispersed and mixed, and reacted under heat and pressure (100 ° C.
  • a catalyst for carbon nanotube production by a hydrothermal method is prepared by mixing and stirring an iron compound and an Mg compound in water, heating the mixture, and hydrothermal reaction by pressurization to obtain a catalyst precursor. Obtained by heating the body at a specific temperature.
  • the iron compound and the Mg compound are each hydrolyzed to become a composite hydroxide via dehydration polycondensation. This becomes a catalyst precursor in a state where iron is highly dispersed in Mg hydroxide.
  • Mg compound nitrate, nitrite, sulfate, ammonium sulfate, carbonate, acetate, citrate, oxide and hydroxide are preferable, and oxide is more preferable.
  • the amount of the iron compound and the Mg compound used may be mixed in two layers so that the amount of the iron component in the iron compound is 0.1 wt% or more and 1 wt% or less with respect to the MgO equivalent amount of the Mg compound. It is preferable in terms of easy production of the contained relatively thin carbon nanotube, and more preferably in the range of 0.2 wt% or more and 0.6 wt% or less.
  • the water and Mg compound are preferably mixed at a molar ratio of 4: 1 to 100: 1, more preferably 9: 1 to 50: 1, and further preferably 9: 1 to 30: 1.
  • the iron compound and Mg compound may be mixed and stirred in water after mixing, concentrating and drying in advance, and the hydrothermal reaction may be carried out. However, in order to simplify the process, the iron compound and Mg compound are directly combined.
  • it is preferably subjected to a hydrothermal reaction.
  • the hydrothermal reaction is carried out under heating and pressure, but it is preferable to generate a self-generated pressure by heating the mixed water containing the suspension in a pressure vessel such as an autoclave in the range of 100 ° C to 250 ° C.
  • the heating temperature is more preferably in the range of 100 ° C to 200 ° C. It is also possible to apply pressure by adding an inert gas.
  • the heating time at the time of hydrothermal reaction is closely related to the heating temperature, usually 30 minutes to 10 hours, and the higher the temperature, the shorter the hydrothermal reaction. Is short. For example, when it is performed at 250 ° C., 30 minutes to 2 hours are preferable, and when it is performed at 100 ° C., 2 hours to 10 hours are preferable.
  • the catalyst precursor is a slurry suspension.
  • the recovery method is not particularly limited, but the catalyst precursor can be easily recovered preferably by filtration or centrifugation. More preferably, filtration is performed, and either suction filtration or natural filtration may be performed.
  • the catalyst precursor subjected to solid-liquid separation is a composite hydroxide of iron and Mg, and when heated, becomes a composite oxide of iron and Mg.
  • the heat treatment is performed in the atmosphere or in an inert gas such as nitrogen, argon, helium, etc., and is preferably heated in the range of 400 ° C. to 1000 ° C., more preferably in the range of 400 ° C. to 700 ° C.
  • the heating time is preferably in the range of 1 to 5 hours. Since the catalyst precursor before heating is mainly composed of Mg hydroxide, it has a flaky primary structure.
  • the reaction system is not particularly limited, but the reaction is preferably carried out using a vertical fluidized bed reactor.
  • the vertical fluidized bed reactor is a reactor installed so that methane as a raw material (carbon source) flows in a vertical direction (hereinafter sometimes referred to as “longitudinal direction”). Methane flows in the direction from one end of the reactor toward the other end and passes through the catalyst layer.
  • a reactor having a tube shape can be preferably used.
  • the vertical direction includes a direction having a slight inclination angle with respect to the vertical direction (for example, 90 ° ⁇ 15 °, preferably 90 ° ⁇ 10 ° with respect to the horizontal plane).
  • the methane supply section and the discharge section do not necessarily have to be end portions of the reactor, and methane may flow in the above-described direction and pass through the catalyst layer in the flow process.
  • FIG. 2 is a schematic diagram showing a configuration example of a carbon nanotube production apparatus for producing a carbon nanotube of a double-walled carbon nanotube-containing composite according to the present embodiment.
  • a synthesis apparatus 100 shown in FIG. 2 is provided on the outer periphery of a reaction tube 101 that synthesizes carbon nanotubes using a carbon source such as methane, and generates heat when energized.
  • a carrier gas supply for supplying a carrier gas as a mobile phase connected to a linear velocity control unit 104 for controlling the linear velocity of the carbon source from the source supply unit 104a and a side pipe 103a branched at the center of the introduction pipe 103
  • Catalyst holding unit having a linear velocity control unit 105 that controls the linear velocity of the carrier gas from the unit 105a and a quartz sintered plate 106a that is provided at the end of the introduction tube 103 on the reaction tube 101 side and that holds the catalyst.
  • Comprising 106 a recovery unit 107 for recovering the carbon nanotubes produced in the reaction tube 101, a thermometer 108 for measuring the temperature of the catalyst retaining section 106, a.
  • the recovery unit 107 is provided with a gas exhaust pipe 107 a that exhausts the carrier gas and the like that has passed through the reaction tube 101 and the recovery unit 107.
  • the catalyst is in a state of being present in the entire horizontal cross-sectional direction of the reactor in the vertical fluidized bed reactor, and a fluidized bed is formed during the reaction. By doing in this way, a catalyst and methane can be made to contact effectively.
  • a quartz sintered plate 106a which is a table for placing the catalyst, is installed in the reaction tube 101, and the catalyst layer formed thereon exists over the entire horizontal cross-sectional direction of the reaction tube 101. .
  • the fluidized bed type is preferable because continuous synthesis is possible by continuously supplying a catalyst and continuously removing the catalyst and carbon nanotubes after the reaction, and carbon nanotubes can be obtained efficiently.
  • the carbon nanotube synthesis reaction is performed uniformly, the catalyst coating by impurities such as amorphous carbon is suppressed, and the catalyst activity is expected to continue for a long time. .
  • a horizontal reactor In contrast to a vertical reactor, a horizontal reactor has a laterally (horizontal) reactor in which a catalyst placed on a quartz plate is placed, and methane passes over the catalyst. It refers to a reaction device in a mode of contacting and reacting. In this case, carbon nanotubes are generated on the catalyst surface, but methane does not reach the inside of the catalyst, so that the yield tends to be lower than that of the vertical reactor. In contrast, in the vertical reactor, the raw material methane can be brought into contact with the entire catalyst, so that a large amount of carbon nanotubes can be efficiently synthesized.
  • the reactor is preferably heat resistant and is preferably made of a heat resistant material such as quartz or alumina.
  • Methane is distributed at a linear speed of 8 cm / sec or higher.
  • the carbon nanotube synthesis reaction in order to increase the decomposition efficiency of methane and increase the yield, it was usual to circulate methane at a low linear velocity.
  • the aggregate of the catalyst is larger than the conventional one. is doing. Therefore, when flowing at a low linear velocity and at a heating temperature, the catalyst layer does not flow, and a problem of so-called short path occurs in which methane passes only through the most easily passing portion of the catalyst layer. Therefore, the linear velocity is preferably 8 cm / sec or more and 10 cm / sec or less.
  • the synthesized double-walled carbon nanotubes are usually removed from the catalyst and subjected to complex formation through purification, oxidation treatment or the like, if necessary.
  • the inner layer side with respect to the slope of the straight line derived from the outer layer side carbon nanotubes Since the ratio of the slope of the straight line derived from the carbon nanotube is 0.5 or more and 1.5 or less, the double-walled carbon nanotube has high mechanical strength and high affinity between the double-walled carbon nanotube and the resin. A complex can be obtained.
  • the autoclave container was allowed to cool, the slurry-like cloudy substance was taken out from the container, and excess water was separated by suction filtration.
  • the moisture content in the filtered product at this time was 2.16.
  • the filtered product was dried by heating in a dryer at 120 ° C. to evaporate water.
  • a catalyst having a particle size in the range of 0.85 mm to 2.36 mm was recovered by using a sieve while refining the obtained solid content in a mortar.
  • the obtained catalyst contained 27.5% of a catalyst having a particle size in the range of 2.0 mm to 2.36 mm.
  • These granular catalysts were introduced into an electric furnace and heated at 600 ° C. for 3 hours in the atmosphere.
  • the iron content in the catalyst was 0.40 wt%.
  • Carbon nanotubes were synthesized using the synthesis apparatus 100 shown in FIG.
  • a cylindrical quartz tube having an inner diameter of 75 mm and a length in the central axis direction of 1100 mm was used.
  • three electric furnaces 102 having an annular shape surrounding the circumference of the reaction tube 101 were arranged so that the reaction tube 101 could be maintained at an arbitrary temperature.
  • the prepared solid catalyst 132 g is taken and introduced onto the quartz sintered plate 106 a at the center of the reaction tube 101 installed in the vertical direction to form a catalyst layer on the catalyst holding unit 106. It was. While the catalyst layer is heated until the temperature in the reaction tube 101 reaches about 860 ° C., 21.6 L of nitrogen gas is controlled from the bottom of the reaction tube 101 toward the top of the reaction tube 101 under the control of the linear velocity control unit 105. / Min, and allowed to pass through the catalyst layer. Thereafter, while supplying nitrogen gas, under the control of the linear velocity control unit 104, methane gas was introduced at 1.0 L / min for 46 minutes, vented so as to pass through the catalyst layer, and reacted.
  • the linear velocity (v) of the gas containing methane at this time was 8.55 cm / sec.
  • the introduction of methane gas was stopped, and the inside of the reaction tube 101 was cooled to room temperature while supplying nitrogen gas at 21.6 L / min.
  • the heating was stopped and the mixture was allowed to stand at room temperature, and after reaching room temperature, the catalyst and carbon nanotubes were taken out from the reactor.
  • Concentrated nitric acid (first grade Assay 60% manufactured by Kishida Chemical Co., Ltd.) about 0.3 times the weight was added to the dry weight of the obtained carbon nanotubes in the wet state. Thereafter, the mixture was heated to reflux with stirring in an oil bath heated to about 140 ° C. for 24 hours. After heating to reflux, the mixture was allowed to cool to room temperature, a nitric acid solution containing carbon nanotubes was diluted 3 times with ion-exchanged water, and an omnipore membrane filter (Millipore, filter type: 1.0 ⁇ m JA) was installed. Suction filtration was performed using a filter (liquid phase oxidation treatment). After washing with ion-exchanged water until the suspension of the filtered material became neutral, carbon nanotubes (first wet cake) were obtained in a wet state containing water.
  • the obtained first wet cake was added to 0.3 L of a 28% aqueous ammonia solution (special grade, manufactured by Kishida Chemical Co., Ltd.) and stirred at room temperature for 1 hour. Thereafter, the solution was subjected to suction filtration (ammonia treatment) using a filter having an inner diameter of 90 mm provided with an omnipore membrane filter (manufactured by Millipore, filter type: 1.0 ⁇ m JA). Thereafter, the membrane was washed with ion-exchanged water until the wet cake on the membrane filter became near neutral, and carbon nanotubes (second wet cake) were obtained in a wet state containing water.
  • a 28% aqueous ammonia solution special grade, manufactured by Kishida Chemical Co., Ltd.
  • the obtained 2nd wet cake was added in 0.3 L of 60% nitric acid aqueous solution (Kishida Chemical Co., Ltd. grade 1 Assay 60%). After stirring at room temperature for 24 hours, suction filtration was performed using a filter having an inner diameter of 90 mm equipped with an Omnipore membrane filter (filter type: 1.0 ⁇ m JA) manufactured by Millipore (nitric acid dope). Thereafter, the membrane was washed with ion-exchanged water until the wet cake on the membrane filter became near neutral. Wet carbon nanotubes (third wet cake) containing water obtained by this washing treatment were stored.
  • the obtained wet carbon nanotubes (third wet cake) were used in a dried form by appropriately evaporating water with a 120 ° C. drier.
  • purification treatment was performed as follows. First, a 6N aqueous hydrochloric acid solution was added to the calcined carbon nanotube aggregate, and the mixture was stirred in a water bath at 80 ° C. for 2 hours. The recovered material obtained by filtration using a filter having a pore diameter of 1 ⁇ m was added to a 6N aqueous hydrochloric acid solution, and stirred in a water bath at 80 ° C. for 60 minutes. This was filtered using a filter having a pore diameter of 1 ⁇ m, washed with water several times, and then the filtrate was dried in an oven at 120 ° C. overnight to remove magnesia and metal, thereby purifying the carbon nanotubes.
  • Raman spectroscopy measurement was performed on the double-walled carbon nanotubes obtained as described above.
  • a powder sample was placed on a Raman spectrometer (INF-300 manufactured by Horiba Joban Yvon), and measurement was performed using a laser wavelength of 633 nm.
  • the analysis was performed at three different locations, and an arithmetic average was taken.
  • the G / D ratio was 52, and it was a high-quality double-walled carbon nanotube with a high degree of graphitization.
  • XPS analysis of double-walled carbon nanotubes obtained by purification step 1 XPS (X-ray Photoelectron Spectroscopy, X-ray photoelectron spectroscopy) measurement was performed on the double-walled carbon nanotubes produced as described above. XPS measurement was performed under the following conditions. Excitation X-ray: Monochromatic Al K 1, 2 wire X-ray diameter: 1000 ⁇ m Photoelectron escape angle: 90 ° (inclination of detector with respect to sample surface)
  • the nanotube composite was prepared using a two-component mixed epoxy composed of an epoxy resin (Araldite (registered trademark) LY 5052) and a curing agent (Araldite (registered trademark) HY 5052).
  • the carbon nanotubes were dispersed in the curing agent using an ultrasonic probe (Ultrasonic Processor CPX 750 manufactured by Cole-Parmer, amplitude 35%, output 750 W).
  • Ultrasonic Processor CPX 750 manufactured by Cole-Parmer, amplitude 35%, output 750 W.
  • the carbon nanotube-epoxy composite was cast on an epoxy cured material having the same composition and not containing carbon nanotubes, and allowed to stand at room temperature for 7 days to be cured.
  • the carbon nanotube concentration of the composite was about 0.01 wt%.
  • the carbon nanotube-epoxy composite was mechanically strained by 4-point bending with the epoxy material supporting it (see FIG. 1).
  • the distortion to the composite film was given to be equivalent to the surface distortion of the epoxy material, and the distortion was measured with a strain gauge.
  • Raman spectra from carbon nanotubes were collected at different strain levels in the 0-0.4% tensile strain range.
  • FIG. 3 is a graph showing the relationship between strain and G ′ band shift in carbon nanotubes of a double-walled carbon nanotube-containing composite according to an example of the present invention. Raman spectroscopic analysis was performed using a laser wavelength of 633 nm. As shown in FIG. 3, G ′ 1 band shift and G ′ 2 band shift, which are G ′ band shifts divided into two peaks, are plotted against the added distortion.
  • the inclination corresponding to G ′ 1 indicating the outer layer side carbon nanotube was ⁇ 18.2 cm ⁇ 1 /%
  • the inclination corresponding to G ′ 2 indicating the inner layer side carbon nanotube was ⁇ 17.0 cm ⁇ 1 /%.
  • the inclination of the straight line derived from the inner layer side carbon nanotubes (inclination of the inner layer / inclination of the outer layer) with respect to the inclination of the straight line derived from the outer layer side carbon nanotubes was 0.93. This not only indicates that the stress transmission between the inner-layer side carbon nanotubes and the outer-layer side carbon nanotubes when strain is applied to the composite is large, and bears almost the same stress. In contrast, the stress transmission between the matrix epoxy resin and the outer-layer side carbon nanotubes is large.
  • FIG. 4 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotubes of the double-walled carbon nanotube-containing composite according to this example.
  • Raman spectroscopic analysis was performed using a laser wavelength of 633 nm.
  • G ′ 1 band shift and G ′ 2 band shift which are G ′ band shifts divided into two peaks, are plotted against the added distortion.
  • the slope corresponding to G ′ 2 indicating the inner layer side carbon nanotube was ⁇ 23.0 cm ⁇ 1 /%
  • the slope corresponding to G ′ 1 indicating the outer layer side carbon nanotube was ⁇ 29.0 cm ⁇ 1 /%.
  • FIG. 5 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotubes of the double-walled carbon nanotube-containing composite according to this example.
  • G ′ 1 band shift and G ′ 2 band shift which are G ′ band shifts divided into two peaks, are plotted against the added distortion.
  • the slope corresponding to G ′ 2 indicating the inner layer side carbon nanotube was ⁇ 19.0 cm ⁇ 1 /%
  • the slope corresponding to G ′ 1 indicating the outer layer side carbon nanotube was ⁇ 26.0 cm ⁇ 1 /%.
  • FIG. 6 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotubes of the double-walled carbon nanotube-containing composite according to this example. As shown in FIG. 6, G ′ 1 band shift and G ′ 2 band shift, which are G ′ band shifts divided into two peaks, are plotted against the added distortion.
  • the slope corresponding to G ′ 2 indicating the inner-layer side carbon nanotube was ⁇ 20.0 cm ⁇ 1 /%
  • the slope corresponding to G ′ 1 indicating the outer-layer side carbon nanotube was ⁇ 24.0 cm ⁇ 1 /%.
  • FIG. 7 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotubes of the double-walled carbon nanotube-containing composite according to this example.
  • G ′ 1 band shift and G ′ 2 band shift which are G ′ band shifts divided into two peaks, were plotted against the added distortion.
  • the slope corresponding to G ′ 2 indicating the inner layer side carbon nanotube was ⁇ 18.0 cm ⁇ 1 /%
  • the slope corresponding to G ′ 1 indicating the outer layer side carbon nanotube was ⁇ 24.0 cm ⁇ 1 /%.
  • Double-walled carbon nanotubes were produced from commercially available arc discharge single-walled carbon nanotubes (Nanocarblab). First, single-walled carbon nanotubes were supplied after being purified through nitric acid treatment, heat treatment in air, and heat treatment at 1000 ° C. in argon. In order to minimize the fragmentation (shortening) effect of the single-walled carbon nanotube and to facilitate the subsequent dispersion step in the polymer, the drying step was performed by freeze drying.
  • the material resulting from this treatment was a powder containing about 70% single-walled carbon nanotubes and about 30% multi-walled carbon shell (for details see S.Cui, et.al., Advanced Materials, 21 ( 2009) See 3591 Supporting Information).
  • the single-walled carbon nanotubes (SWNTs) were mixed with a commercially available fullerene (manufactured by ALFA AESAR, 98% C 60 + 2% C 70 , purity> 98%) and then introduced into a quartz ampoule. In order to facilitate water dispersibility, nitrogen replacement and evacuation were repeated while maintaining the inside of the ampoule at 200 ° C., and finally, sealing was performed in a vacuum state.
  • Ampoule was placed in a heat treatment furnace maintained at about 500 ° C., for 24 hours so that the (SWNTs containing C 60) peapods material. The yield of peapod material was about 75%. The other components remained as single-walled carbon nanotubes.
  • the quartz ampoule was opened, placed in a heat treatment furnace and processed in vacuum up to 1300 ° C. By this treatment, fullerenes were combined to form single-walled carbon nanotubes, and single-walled carbon nanotubes, that is, double-walled carbon nanotubes were synthesized in the single-walled carbon nanotubes. Excess fullerene that was not introduced into the single-walled carbon nanotubes was removed by sublimation in the heat treatment temperature rising process.
  • FIG. 8 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotube of the double-walled carbon nanotube-containing composite according to this example (Comparative Example 1).
  • G ′ 1 band shift and G ′ 2 band shift which are G ′ band shifts divided into two peaks, are plotted against the added distortion.
  • the inclination according to G ′ 1 indicating the outer layer side carbon nanotube was ⁇ 11 cm ⁇ 1 /%
  • the inclination according to G ′ 2 indicating the inner layer side carbon nanotube was ⁇ 0.7 cm ⁇ 1 /%.
  • the double-walled carbon nanotube-containing composite of the present invention can be suitably used to obtain a double-walled carbon nanotube-containing composite having high affinity between the double-walled carbon nanotube and the resin and high mechanical strength.

Abstract

A complex containing double-walled carbon nanotubes, which comprises: double-walled carbon nanotubes each composed of an inner-layer-side carbon nanotube and an outer-layer-side carbon nanotube; and a resin. In a graph illustrating the relationship between the strain and the G' band shift of the complex containing double-walled carbon nanotubes, which is a graph produced by carrying out a Raman spectroscopic analysis of the complex containing double-walled carbon nanotubes while applying a load to the complex containing double-walled carbon nanotubes, the ratio of the slope of a line derived from the inner-layer-side carbon nanotube to the slope of a line derived from the outer-layer-side carbon nanotube is 0.5 to 1.5 inclusive.

Description

２層カーボンナノチューブ含有複合体Double-walled carbon nanotube-containing composite
　本発明は、２層カーボンナノチューブ含有複合体に関する。 The present invention relates to a composite containing a double-walled carbon nanotube.
　カーボンナノチューブは、六角網目状の炭素原子配列のグラファイトシートが円筒状に巻かれた構造を有する物質であり、１層に巻かれたものを単層カーボンナノチューブ、多層に巻かれたものを多層カーボンナノチューブという。多層カーボンナノチューブの中でも特に２層に巻かれたものを２層カーボンナノチューブという。カーボンナノチューブは、優れた導電性や高い機械強度を有し、導電性材料や補強材料として使用されることが期待されている。 A carbon nanotube is a substance having a structure in which a graphite sheet having a hexagonal network of carbon atoms arranged in a cylindrical shape is wound. A single-walled carbon nanotube is a single-walled carbon nanotube, and a multi-walled carbon is wound in multiple layers. It is called a nanotube. Among multi-walled carbon nanotubes, those wound in two layers are called double-walled carbon nanotubes. Carbon nanotubes have excellent conductivity and high mechanical strength, and are expected to be used as conductive materials and reinforcing materials.
　通常、カーボンナノチューブのうち、層数の少ない単層カーボンナノチューブや２層カーボンナノチューブが、高グラファイト構造を有しているために導電性や熱伝導性などの特性が高いことが知られている。 Usually, among carbon nanotubes, single-walled carbon nanotubes and double-walled carbon nanotubes with a small number of layers are known to have high properties such as conductivity and thermal conductivity because they have a high graphite structure.
　一方、カーボンナノチューブを樹脂に添加し、樹脂特性を向上させる技術が知られている（例えば、特許文献１を参照）。この技術において、層数の少ない単層カーボンナノチューブが、添加量に対して最も複合体特性を向上させる効果が高いと考えられる。 On the other hand, a technique for improving the resin characteristics by adding carbon nanotubes to a resin is known (for example, see Patent Document 1). In this technique, single-walled carbon nanotubes with a small number of layers are considered to have the highest effect of improving composite properties with respect to the amount added.
　ここで、複合体の特性を向上させるためには、カーボンナノチューブと樹脂との親和性を向上させることが重要である。これに対し、カーボンナノチューブと樹脂との親和性向上のために、カーボンナノチューブ側壁に官能基を導入して、複合体の特性を向上させる技術が知られている（例えば、特許文献２を参照）。 Here, in order to improve the properties of the composite, it is important to improve the affinity between the carbon nanotube and the resin. On the other hand, in order to improve the affinity between the carbon nanotube and the resin, a technique for improving the properties of the composite by introducing a functional group into the side wall of the carbon nanotube is known (for example, see Patent Document 2). .
特表２００９－５３２５３１号公報Special table 2009-532531 特開２００６－２４０９３８号公報JP 2006-240938 A
　ところで、特許文献２に記載の技術において、単層カーボンナノチューブを用いた場合、側壁の官能基化により単層カーボンナノチューブ自身のグラファイト性が低下する。このため、単層カーボンナノチューブ自身が有する機械強度などの特性が大きく低下するという課題を抱えていた。一方、２層カーボンナノチューブなどの多層カーボンナノチューブを用いると、外層を官能基化しても、内層が保持するグラファイト性により、カーボンナノチューブ特性が維持できると期待されていた。 By the way, in the technique described in Patent Document 2, when single-walled carbon nanotubes are used, the graphite properties of the single-walled carbon nanotubes themselves are lowered due to functionalization of the side walls. For this reason, there has been a problem that characteristics such as mechanical strength of the single-walled carbon nanotube itself are greatly deteriorated. On the other hand, when multi-walled carbon nanotubes such as double-walled carbon nanotubes are used, it has been expected that even if the outer layer is functionalized, the carbon nanotube characteristics can be maintained due to the graphite property retained by the inner layer.
　しかしながら、２層カーボンナノチューブを用いた場合、十分な特性を発揮できていないのが現状であった。なお、２層カーボンナノチューブの側壁の官能基化では、２層カーボンナノチューブの外層と内層とがそれぞれ相互作用せず、応力伝搬していないことが十分な特性を発揮できていない原因として考えられる。 However, when double-walled carbon nanotubes are used, the present situation is that sufficient characteristics cannot be exhibited. In addition, in the functionalization of the side wall of the double-walled carbon nanotube, it is considered that the outer layer and the inner layer of the double-walled carbon nanotube do not interact with each other and the stress is not propagated as a cause of insufficient performance.
　本発明は、上記に鑑みてなされたものであり、２層カーボンナノチューブと樹脂の親和性が高く、かつ高い機械強度を有する複合体を提供することを目的とする。 The present invention has been made in view of the above, and an object of the present invention is to provide a composite having a high affinity between a double-walled carbon nanotube and a resin and a high mechanical strength.
　上述した課題を解決し、目的を達成するために、本発明にかかる２層カーボンナノチューブ含有複合体は、内層側カーボンナノチューブおよび外層側カーボンナノチューブからなる２層カーボンナノチューブと、樹脂とを含む２層カーボンナノチューブ含有複合体であって、荷重を加えた状態でラマン分光分析した場合に得られる当該２層カーボンナノチューブ含有複合体の歪みとＧ’バンドシフトとの関係を示すグラフにおいて、前記外層側カーボンナノチューブに由来する直線の傾きに対する前記内層側カーボンナノチューブに由来する直線の傾きの比の値が、０．５以上１．５以下であることを特徴とする。 In order to solve the above-described problems and achieve the object, a double-walled carbon nanotube-containing composite according to the present invention includes a double-walled carbon nanotube comprising an inner-layer side carbon nanotube and an outer-layer side carbon nanotube, and a resin In the graph showing the relationship between the strain of the double-walled carbon nanotube-containing composite and the G ′ band shift, which is obtained when a Raman spectroscopic analysis is performed in a state where a load is applied, The ratio of the slope of the straight line derived from the inner-wall-side carbon nanotube to the slope of the straight line derived from the nanotube is from 0.5 to 1.5.
　また、本発明にかかる２層カーボンナノチューブ含有複合体は、上記の発明において、前記２層カーボンナノチューブは、酸素を含む官能基で修飾されていることを特徴とする。 Further, the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the double-walled carbon nanotube is modified with a functional group containing oxygen.
　また、本発明にかかる２層カーボンナノチューブ含有複合体は、上記の発明において、前記官能基は、水酸基またはカルボシキル基であることを特徴とする。 The double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the functional group is a hydroxyl group or a carboxyl group.
　また、本発明にかかる２層カーボンナノチューブ含有複合体は、上記の発明において、前記２層カーボンナノチューブ中の炭素原子に対する酸素原子の割合が、０．１ａｔ％以上２０ａｔ％以下であることを特徴とする。 Further, the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above-mentioned invention, a ratio of oxygen atoms to carbon atoms in the double-walled carbon nanotube is 0.1 at% or more and 20 at% or less. To do.
　また、本発明にかかる２層カーボンナノチューブ含有複合体は、上記の発明において、前記２層カーボンナノチューブを波長６３３ｎｍでラマン分光分析した場合のＤバンドの高さに対するＧバンドの高さの比の値が、２０以上であることを特徴とする。 Further, the double-walled carbon nanotube-containing composite according to the present invention is the value of the ratio of the G-band height to the D-band height when the double-walled carbon nanotube is subjected to Raman spectroscopic analysis at a wavelength of 633 nm. Is 20 or more.
　また、本発明にかかる２層カーボンナノチューブ含有複合体は、上記の発明において、前記樹脂は、熱硬化性樹脂であることを特徴とする。 Further, the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the resin is a thermosetting resin.
　また、本発明にかかる２層カーボンナノチューブ含有複合体は、上記の発明において、前記樹脂は、エポキシ樹脂であることを特徴とする。 Further, the double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the resin is an epoxy resin.
　また、本発明にかかる２層カーボンナノチューブ含有複合体は、上記の発明において、前記２層カーボンナノチューブは、前記樹脂に対して、０．００１重量％以上１０重量％以下で含まれることを特徴とする。 The double-walled carbon nanotube-containing composite according to the present invention is characterized in that, in the above invention, the double-walled carbon nanotube is contained in an amount of 0.001 wt% to 10 wt% with respect to the resin. To do.
　また、本発明にかかる２層カーボンナノチューブ含有複合体は、上記の発明において、前記外層側カーボンナノチューブに由来する直線の傾きの絶対値が、１０ｃｍ－１／％以上５０ｃｍ－１／％以下であることを特徴とする。 Also, double-walled carbon nanotube-containing composite of the present invention, in the above invention, the absolute value of the slope of the line from the outer side carbon nanotubes, is 10 cm -1 /% or more 50 cm -1 /% or less It is characterized by that.
　本発明によれば、ある特定の２層カーボンナノチューブと樹脂の複合体とを用いることで、２層カーボンナノチューブと樹脂の親和性が高く、さらには２層カーボンナノチューブの内層と外層が応力伝搬し、良好な力学特性を示す複合体を得ることができる。 According to the present invention, by using a specific composite of a double-walled carbon nanotube and a resin, the affinity between the double-walled carbon nanotube and the resin is high, and furthermore, the inner layer and the outer layer of the double-walled carbon nanotube propagate stress. A composite exhibiting good mechanical properties can be obtained.
図１は、本発明の実施の形態にかかる２層カーボンナノチューブ含有複合体に対するラマン分光分析を説明するための図である。FIG. 1 is a diagram for explaining Raman spectroscopic analysis for a double-walled carbon nanotube-containing composite according to an embodiment of the present invention. 図２は、本発明の実施の形態にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブを製造するカーボンナノチューブ製造装置の構成例を示す模式図である。FIG. 2 is a schematic diagram showing a configuration example of a carbon nanotube production apparatus for producing a carbon nanotube of a double-walled carbon nanotube-containing composite according to an embodiment of the present invention. 図３は、本発明の実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。FIG. 3 is a graph showing the relationship between strain and G ′ band shift in carbon nanotubes of a double-walled carbon nanotube-containing composite according to an example of the present invention. 図４は、本発明の実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。FIG. 4 is a graph showing the relationship between strain and G ′ band shift in carbon nanotubes of a double-walled carbon nanotube-containing composite according to an example of the present invention. 図５は、本発明の実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。FIG. 5 is a graph showing the relationship between strain and G ′ band shift in carbon nanotubes of a double-walled carbon nanotube-containing composite according to an example of the present invention. 図６は、本発明の実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。FIG. 6 is a graph showing the relationship between strain and G ′ band shift in a carbon nanotube of a double-walled carbon nanotube-containing composite according to an example of the present invention. 図７は、本発明の実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。FIG. 7 is a graph showing the relationship between strain and G ′ band shift in a carbon nanotube of a double-walled carbon nanotube-containing composite according to an example of the present invention. 図８は、本発明の実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。FIG. 8 is a graph showing the relationship between strain and G ′ band shift in a carbon nanotube of a double-walled carbon nanotube-containing composite according to an example of the present invention.
　以下、本発明を実施するための形態を詳細に説明する。なお、以下の実施の形態により本発明が限定されるものではない。 Hereinafter, embodiments for carrying out the present invention will be described in detail. In addition, this invention is not limited by the following embodiment.
　本発明にかかる２層カーボンナノチューブ含有複合体は、直径の異なる２本のカーボンナノチューブ（内層側カーボンナノチューブおよび外層側カーボンナノチューブ）が同心円状に重なってなる２層カーボンナノチューブと、樹脂とを含む複合体である。また、２層カーボンナノチューブは、複合体に荷重を加えてラマン分光分析した時に得られる複合体の歪みとＧ’バンドシフトとの関係を示すグラフにおいて、外層側カーボンナノチューブに由来する直線の傾きに対する内層側カーボンナノチューブに由来する直線の傾きの比（内層の傾き／外層の傾き）の値が、０．５以上１．５以下である。 The double-walled carbon nanotube-containing composite according to the present invention includes a double-walled carbon nanotube in which two carbon nanotubes having different diameters (inner-wall side carbon nanotube and outer-layer side carbon nanotube) are concentrically overlapped, and a resin. Is the body. In addition, the double-walled carbon nanotube is a graph showing the relationship between the distortion of the composite and the G ′ band shift obtained when a Raman spectroscopic analysis is applied to the composite. The ratio of the slope of the straight line derived from the inner-layer-side carbon nanotube (the slope of the inner layer / the slope of the outer layer) is 0.5 or more and 1.5 or less.
　ここで、カーボンナノチューブは、グラファイトの１枚面を巻いて筒状にした形状をなしており、１層に巻いたものを単層カーボンナノチューブ、多層に巻いたものを多層カーボンナノチューブという。多層カーボンナノチューブの中でも特に２層に巻いたものを２層カーボンナノチューブという。本発明において用いられる２層カーボンナノチューブとは、複数の２層カーボンナノチューブが存在している総体を意味し、その存在形態は特に限定されず、それぞれが独立で、あるいは束状、絡まり合うなどの形態あるいはこれらの混合形態で存在していてもよい。また、カーボンナノチューブ製造法由来の不純物（例えば触媒）を含み得るが、実質的には炭素で構成されたものを示す。また、種々の直径のものが含まれていてもよい。 Here, the carbon nanotubes have a shape in which one surface of graphite is wound into a cylindrical shape, and a single-walled carbon nanotube is a single-walled carbon nanotube and a multi-walled carbon nanotube is a single-walled carbon nanotube. Among multi-walled carbon nanotubes, those wound in two layers are called double-walled carbon nanotubes. The double-walled carbon nanotube used in the present invention means a total of a plurality of double-walled carbon nanotubes, and the form of existence thereof is not particularly limited, and each is independent or bundled or entangled. It may exist in the form or a mixed form thereof. Moreover, although the impurity (for example, catalyst) derived from a carbon nanotube manufacturing method may be included, the thing comprised substantially by carbon is shown. Moreover, the thing of various diameter may be contained.
　カーボンナノチューブの形態は、高分解能透過型電子顕微鏡で調べることができる。グラファイトの層は、透過型電子顕微鏡でまっすぐにはっきりと見えるほど好ましいが、グラファイトの層は乱れていても構わない。 The morphology of carbon nanotubes can be examined with a high-resolution transmission electron microscope. The graphite layer is preferred so that it can be seen straight and clearly in a transmission electron microscope, but the graphite layer may be disordered.
　本発明において用いられるカーボンナノチューブは、種々の層数のカーボンナノチューブを含んでいてもよいが、２層カーボンナノチューブを主成分とする。主成分とは透過型電子顕微鏡で観測した時に１００本中５０本以上（半数以上）のカーボンナノチューブが２層カーボンナノチューブであることを言う。更には１００本中７０本以上のカーボンナノチューブが２層カーボンナノチューブであることが好ましい。ここでいう本数は、カーボンナノチューブ集合体中に含まれる任意のカーボンナノチューブの１００本を観察し、２層カーボンナノチューブの本数を評価するものとする。 The carbon nanotubes used in the present invention may contain carbon nanotubes having various numbers of layers, but are mainly composed of double-walled carbon nanotubes. The main component means that 50 or more (half or more) of the 100 carbon nanotubes are double-walled carbon nanotubes when observed with a transmission electron microscope. Furthermore, it is preferable that 70 or more of 100 carbon nanotubes are double-walled carbon nanotubes. The number here refers to the evaluation of the number of double-walled carbon nanotubes by observing 100 arbitrary carbon nanotubes contained in the aggregate of carbon nanotubes.
　上記任意のカーボンナノチューブの層数と本数の数え方は、例えば、透過型電子顕微鏡にて４０万倍で観察し、７５ｎｍ四方の視野の中で視野面積の１０％以上がカーボンナノチューブである視野中から任意に抽出した１００本のカーボンナノチューブについて層数を評価する。一つの視野中で１００本の測定ができない場合は、１００本になるまで複数の視野から測定する。このとき、カーボンナノチューブ１本とは視野中で一部カーボンナノチューブが見えていれば１本と計上し、必ずしも両端が見えている必要はない。また視野中で２本と認識されても視野外でつながって１本となっていることもあり得るが、その場合は２本と計上する。 The number of layers and the number of the arbitrary carbon nanotubes can be counted by, for example, observing with a transmission electron microscope at a magnification of 400,000, and in a visual field in which 10% or more of the visual field area is a carbon nanotube in a visual field of 75 nm square. The number of layers is evaluated for 100 carbon nanotubes arbitrarily extracted from. When 100 lines cannot be measured in one field of view, measurement is performed from a plurality of fields until 100 lines are obtained. At this time, one carbon nanotube is counted as one if a part of the carbon nanotube is visible in the field of view, and both ends are not necessarily visible. In addition, even if it is recognized as two in the field of view, it may be connected outside the field of view and become one, but in that case, it is counted as two.
　本発明において用いられるカーボンナノチューブは、その外径の平均値が１．０ｎｍ以上３．０ｎｍ以下の範囲内であるものが好ましく用いられる。この外径の平均値は、上記透過型電子顕微鏡にて４０万倍で観察し、７５ｎｍ四方の視野の中で視野面積の１０％以上がカーボンナノチューブである視野中から任意に抽出した１００本のカーボンナノチューブについて層数を評価するのと同様の方法でサンプルを観察し、カーボンナノチューブの外径を測定したときの算術平均値である。 The carbon nanotubes used in the present invention are preferably those having an average outer diameter in the range of 1.0 nm to 3.0 nm. The average value of the outer diameter was observed with the transmission electron microscope at a magnification of 400,000, and 100 pieces arbitrarily extracted from a field where 10% or more of the field area was a carbon nanotube in a field of view of 75 nm square. It is an arithmetic mean value when a sample is observed by the same method as that for evaluating the number of layers of carbon nanotubes and the outer diameter of the carbon nanotubes is measured.
　本発明において用いられる２層カーボンナノチューブは、酸素を含む官能基で修飾されている。酸素を含む官能基とは、水酸基やカルボキシル基、カルボニル基、エーテル基などがあるが、酸素を含んでいれば特に限定されるものではない。これらの中でも水酸基、カルボキシル基が好ましい。 The double-walled carbon nanotube used in the present invention is modified with a functional group containing oxygen. The functional group containing oxygen includes a hydroxyl group, a carboxyl group, a carbonyl group, an ether group, and the like, but is not particularly limited as long as it contains oxygen. Among these, a hydroxyl group and a carboxyl group are preferable.
　これら官能基量は、Ｘ線光電子分光法（ＸＰＳ）によって確認することができる。例えば、以下の条件でＯ　１ｓのピークを解析することによって確認することができる。
　励起Ｘ線：Ｍｏｎｏｃｈｒｏｍａｔｉｃ　Ａｌ　Ｋ１，２線
　Ｘ線径：１０００μｍ
　光電子脱出角度：９０°（試料表面に対する検出器の傾き） The amount of these functional groups can be confirmed by X-ray photoelectron spectroscopy (XPS). For example, it can be confirmed by analyzing the peak of O 1s under the following conditions.
Excitation X-ray: Monochromatic Al K 1, 2 wire X-ray diameter: 1000 μm
Photoelectron escape angle: 90 ° (inclination of detector with respect to sample surface)
　また、本発明の２層カーボンナノチューブは、上記のような酸素を含む官能基を有しており、２層カーボンナノチューブ中の炭素原子に対する酸素原子の割合が０．１ａｔ％（ａｔｏｍｉｃ％）以上２０ａｔ％以下である。このような炭素原子に対する酸素原子の割合はＸ線光電子分光法（ＸＰＳ）の表面組成解析を用いることで評価が可能である。本発明においては、Ｘ線光電子分光法（ＸＰＳ）の表面組成解析の結果、炭素原子に対する酸素原子の割合が０．１ａｔ％以上２０ａｔ％以下であることが、優れた導電性を示すカーボンナノチューブ集合体となるため好ましい。酸素原子の割合があまりに多い場合は、２層カーボンナノチューブの外層自身がグラファイト性を維持できず、もろくなり内層へ応力がうまく伝搬しない。また酸素原子が少なすぎても、２層カーボンナノチューブと樹脂の親和性が低下し、樹脂からの応力が２層カーボンナノチューブに伝搬しない。より好ましくは炭素原子に対する酸素原子の割合が１ａｔ％以上１５ａｔ％以下である。 In addition, the double-walled carbon nanotube of the present invention has a functional group containing oxygen as described above, and the ratio of the oxygen atom to the carbon atom in the double-walled carbon nanotube is 0.1 at% (atomic%) or more and 20 at%. % Or less. Such a ratio of oxygen atoms to carbon atoms can be evaluated by using surface composition analysis of X-ray photoelectron spectroscopy (XPS). In the present invention, as a result of surface composition analysis by X-ray photoelectron spectroscopy (XPS), the ratio of oxygen atoms to carbon atoms is 0.1 at% or more and 20 at% or less, and the carbon nanotube assembly exhibiting excellent conductivity Since it becomes a body, it is preferable. When the proportion of oxygen atoms is too large, the outer layer of the double-walled carbon nanotube itself cannot maintain the graphitic property and becomes brittle, and the stress does not propagate well to the inner layer. Even if there are too few oxygen atoms, the affinity between the double-walled carbon nanotube and the resin is lowered, and the stress from the resin does not propagate to the double-walled carbon nanotube. More preferably, the ratio of oxygen atoms to carbon atoms is 1 at% or more and 15 at% or less.
　本発明において用いられるカーボンナノチューブは、ラマン分光分析によるＤバンドの高さに対するＧバンドの高さの比（Ｇ／Ｄ比）の値が２０以上であることが好ましい。より好ましくは４０以上２００以下であり、さらに好ましくは５０以上１５０以下である。Ｇ／Ｄ比とはカーボンナノチューブをラマン分光分析法により評価した時の値である。この際、測定装置としては、例えば顕微レーザーラマン分光光度計分析装置（日本分光株式会社製JＡSCO　NRS2100）を使うことができる。また、ラマン分光分析法で使用するレーザー波長は６３３ｎｍである。一般に、ラマン分光分析法により得られるラマンスペクトルにおいて１５９０ｃｍ－１付近に見られるラマンシフトはグラファイト由来のＧバンドと呼ばれ、１３５０ｃｍ－１付近に見られるラマンシフトはアモルファスカーボンやグラファイトの欠陥に由来のＤバンドと呼ばれる。このＧバンド、Ｄバンドの高さ比、Ｇ／Ｄ比が高いカーボンナノチューブほど、グラファイト化度が高く、高品質であることを示している。また、カーボンナノチューブのような固体のラマン分光分析法は、サンプリングによってばらつくことがある。そこで少なくとも３カ所、別の場所をラマン分光分析し、その相加平均をとるものとする。Ｇ／Ｄ比が２０以上とは相当な高品質カーボンナノチューブであることを示している。Ｇ／Ｄ比が２０以下では、元々の２層カーボンナノチューブのグラファイト性が低すぎて内層と外層の応力がうまく伝搬しない。 The carbon nanotubes used in the present invention preferably have a ratio of the G band height to the D band height (G / D ratio) by Raman spectroscopy of 20 or more. More preferably, it is 40 or more and 200 or less, More preferably, it is 50 or more and 150 or less. The G / D ratio is a value when carbon nanotubes are evaluated by Raman spectroscopy. At this time, for example, a microscopic laser Raman spectrophotometer analyzer (JASCO NRS2100 manufactured by JASCO Corporation) can be used as a measuring apparatus. The laser wavelength used in the Raman spectroscopic analysis method is 633 nm. In general, the Raman shift observed in the vicinity of 1590 cm −1 in the Raman spectrum obtained by Raman spectroscopy is called a graphite-derived G band, and the Raman shift observed in the vicinity of 1350 cm −1 is derived from defects in amorphous carbon or graphite. Called the D band. A carbon nanotube having a higher height ratio of G band and D band and a higher G / D ratio indicates a higher degree of graphitization and higher quality. In addition, solid Raman spectroscopy such as carbon nanotubes may vary depending on sampling. Therefore, at least three places and another place are subjected to Raman spectroscopic analysis, and an arithmetic average thereof is taken. A G / D ratio of 20 or more indicates a considerably high quality carbon nanotube. When the G / D ratio is 20 or less, the original double-walled carbon nanotubes are too low in graphite and the stress of the inner layer and the outer layer does not propagate well.
　本発明で用いられる樹脂とは、熱硬化性樹脂、熱可塑性樹脂のいずれでも構わない。好ましくは、熱硬化性樹脂である。 The resin used in the present invention may be either a thermosetting resin or a thermoplastic resin. Preferably, it is a thermosetting resin.
　熱硬化性樹脂は、特に限定されるものではなく、いずれの熱硬化性樹脂も好適に使用することができる。具体的には、不飽和ポリエステル樹脂、ビニルエステル樹脂、エポキシ樹脂、フェノール樹脂、尿素樹脂、メラミン樹脂、ポリイミド等や、これらの共重合体、変性体、および２種類以上ブレンドした樹脂などを使用することができる。中でも、耐熱性、力学特性、および接着性のバランスに優れるエポキシ樹脂が好ましく使用できる。 The thermosetting resin is not particularly limited, and any thermosetting resin can be suitably used. Specifically, unsaturated polyester resins, vinyl ester resins, epoxy resins, phenol resins, urea resins, melamine resins, polyimides, copolymers thereof, modified products, and resins obtained by blending two or more types are used. be able to. Among these, an epoxy resin having an excellent balance of heat resistance, mechanical properties, and adhesiveness can be preferably used.
　エポキシ樹脂としては、特に限定されるものではなく、いずれのエポキシ樹脂も好適に使用することができる。具体的には、ポリオールから得られるグリシジルエーテル、活性水素を複数有するアミンより得られるグリシジルアミン、ポリカルボン酸より得られるグリシジルエステルや、分子内に複数の２重結合を有する化合物を酸化して得られるポリエポキシドなどが用いられる。 The epoxy resin is not particularly limited, and any epoxy resin can be suitably used. Specifically, it is obtained by oxidizing a glycidyl ether obtained from polyol, a glycidyl amine obtained from an amine having a plurality of active hydrogens, a glycidyl ester obtained from a polycarboxylic acid, or a compound having a plurality of double bonds in the molecule. Polyepoxides that can be used are used.
　グリシジルエーテルの具体例としては、以下のようなものが挙げられる。まず、ビスフェノールＡから得られるビスフェノールＡ型エポキシ樹脂、ビスフェノールＦから得られるビスフェノールＦ型エポキシ樹脂、ビスフェノールＳから得られるビスフェノールＳ型エポキシ樹脂、テトラブロモビスフェノールＡから得られるテトラブロモビスフェノールＡ型エポキシ樹脂などのビスフェノール型エポキシ樹脂が挙げられる。ビスフェノールＡ型エポキシ樹脂の市販品としては、“エピコート(登録商標、以下同じ)”８２５、“エピコート”８２８、“エピコート”８３４、“エピコート”１００１、“エピコート”１００２、“エピコート”１００３、“エピコート”１００４、“エピコート”１００７、“エピコート”１００９、“エピコート”１０１０（以上、ジャパンエポキシレジン株式会社製）、“エポトート(登録商標、以下同じ)”ＹＤ－１２８、“エポトート”ＹＤ－０１１、“エポトート”ＹＤ－０１４、“エポトート”ＹＤ－０１７、“エポトート”ＹＤ－０１９、“エポトート”ＹＤ－０２２（以上、東都化成株式会社製）、“エピクロン(登録商標、以下同じ)”８４０、“エピクロン”８５０、“エピクロン”８３０、“エピクロン”１０５０、“エピクロン”３０５０、“エピクロン”ＨＭ－１０１（以上、大日本インキ化学工業株式会社製）、“スミエポキシ(登録商標、以下同じ)”ＥＬＡ－１２８（住友化学株式会社製）、ＤＥＲ３３１（ダウケミカル社製）等を挙げることができる。ビスフェノールＦ型エポキシ樹脂の市販品としては、“エピコート”８０６、“エピコート”８０７、“エピコート”Ｅ４００２Ｐ、“エピコート”Ｅ４００３Ｐ、“エピコート”Ｅ４００４Ｐ、“エピコート”Ｅ４００７Ｐ、“エピコート”Ｅ４００９Ｐ、“エピコート”Ｅ４０１０Ｐ（以上、ジャパンエポキシレジン株式会社製）、“エピクロン”８３０（大日本インキ化学工業株式会社製）、“エポトート”ＹＤＦ－２００１、“エポトート”ＹＤＦ－２００４（以上、東都化成株式会社製）などを挙げることができる。ビスフェノールＳ型エポキシ樹脂の市販品としては、“デナコール(登録商標、以下同じ)”ＥＸ－２５１（ナガセ化成工業株式会社製）、“エピクロン”ＥＸＡ－１５１４（大日本インキ化学工業株式会社製）を挙げることができる。テトラブロモビスフェノールＡ型エポキシ樹脂の市販品としては、“エピコート”５０５０（ジャパンエポキシレジン株式会社製）、“エピクロン”１５２（大日本インキ化学工業株式会社製）、“スミエポキシ”ＥＳＢ－４００Ｔ（住友化学工業株式会社製）、“エポトート”ＹＢＤ－３６０（東都化成株式会社製）を挙げることができる。 Specific examples of glycidyl ether include the following. First, bisphenol A type epoxy resin obtained from bisphenol A, bisphenol F type epoxy resin obtained from bisphenol F, bisphenol S type epoxy resin obtained from bisphenol S, tetrabromobisphenol A type epoxy resin obtained from tetrabromobisphenol A, etc. Bisphenol type epoxy resin. Commercially available bisphenol A type epoxy resins include “Epicoat (registered trademark)” 825, “Epicoat” 828, “Epicoat” 834, “Epicoat” 1001, “Epicoat” 1002, “Epicoat” 1003, “Epicoat” “1004”, “Epicoat” 1007, “Epicoat” 1009, “Epicoat” 1010 (above, manufactured by Japan Epoxy Resin Co., Ltd.), “Epototo (registered trademark, the same applies hereinafter)” YD-128, “Epototo” YD-011, "Epototo" YD-014, "Epototo" YD-017, "Epototo" YD-019, "Epototo" YD-022 (manufactured by Tohto Kasei Co., Ltd.), "Epicron (registered trademark, the same applies hereinafter)" 840, "Epicron "850," Epicron "830," Epicron "1050 “Epicron” 3050, “Epicron” HM-101 (above, Dainippon Ink & Chemicals, Inc.), “Sumiepoxy (registered trademark, the same applies hereinafter)” ELA-128 (Sumitomo Chemical Co., Ltd.), DER331 (Dow Chemical) Manufactured). Commercially available bisphenol F type epoxy resins include “Epicoat” 806, “Epicoat” 807, “Epicoat” E4002P, “Epicoat” E4003P, “Epicoat” E4004P, “Epicoat” E4007P, “Epicoat” E4009P, “Epicoat” E4010P (Made by Japan Epoxy Resin Co., Ltd.), “Epiclon” 830 (Dainippon Ink Chemical Co., Ltd.), “Epototo” YDF-2001, “Epototo” YDF-2004 (above, manufactured by Toto Kasei Co., Ltd.) Can be mentioned. Commercially available bisphenol S-type epoxy resins include “Denacol (registered trademark, the same shall apply hereinafter)” EX-251 (manufactured by Nagase Kasei Kogyo Co., Ltd.) and “Epiclon” EXA-1514 (manufactured by Dainippon Ink & Chemicals, Inc.). Can be mentioned. Commercially available tetrabromobisphenol A type epoxy resins include “Epicoat” 5050 (manufactured by Japan Epoxy Resin Co., Ltd.), “Epicron” 152 (manufactured by Dainippon Ink & Chemicals, Inc.), and “Sumiepoxy” ESB-400T (Sumitomo Chemical). And "Epototo" YBD-360 (manufactured by Toto Kasei Co., Ltd.).
　また、フェノールやアルキルフェノール、ハロゲン化フェノールなどのフェノール誘導体から得られるノボラックのグリシジルエーテルであるノボラック型エポキシ樹脂の市販品としては、“エピコート”１５２、“エピコート”１５４、“エピコート”１５７（以上、ジャパンエポキシレジン株式会社製）、ＤＥＲ４３８（ダウケミカル社製）、“アラルダイト(登録商標、以下同じ)”ＥＰＮ１１３８（ＢＡＳＦ社製）、“アラルダイト”ＥＰＮ１１３９（ＢＡＳＦ社製）、“エポトート”ＹＣＰＮ－７０２（東都化成株式会社製）、ＢＲＥＮ－１０５（日本化薬株式会社製）を挙げることができる。 In addition, commercially available products of novolak type epoxy resins, which are glycidyl ethers of novolac obtained from phenol derivatives such as phenol, alkylphenol and halogenated phenol, are “Epicoat” 152, “Epicoat” 154, “Epicoat” 157 (above, Japan). Epoxy Resin Co., Ltd.), DER 438 (Dow Chemical Co., Ltd.), “Araldite (registered trademark, the same applies hereinafter)” EPN1138 (BASF Corp.), “Araldite” EPN1139 (BASF Corp.), “Epototo” YCPN-702 (Tokyo) And BREN-105 (manufactured by Nippon Kayaku Co., Ltd.).
　その他にも、レゾルシンジグリシジルエーテルである“デナコール”ＥＸ－２０１（ナガセ化成工業株式会社製）、ヒドロキノンジグリシジルエーテルである“デナコール”ＥＸ－２０３（ナガセ化成工業株式会社製）、トリス(ｐ－ヒドロキシフェニル)メタンのトリグリシジルエーテルであるＴＡＣＴＩＸ７４２（ダウケミカル社製）、テトラキス(ｐ－ヒドロキシフェニル)エタンのテトラグリシジルエーテルである“エピコート”１０３１Ｓ（ジャパンエポキシレジン株式会社製）、グリセリンのトリグリシジルエーテルである“デナコール”ＥＸ－３１４（ナガセ化成工業株式会社製）、ペンタエリスリトールのテトラグリシジルエーテルである“デナコール”ＥＸ－４１１（ナガセ化成工業株式会社製）などを挙げることができる。 In addition, “Denacol” EX-201 (manufactured by Nagase Kasei Kogyo Co., Ltd.) which is resorcin diglycidyl ether, “Denacol” EX-203 (manufactured by Nagase Kasei Kogyo Co., Ltd.), hydroquinone diglycidyl ether, Tris (p- TACTIX 742 which is triglycidyl ether of hydroxyphenyl) methane (manufactured by Dow Chemical Co.), “Epicoat” 1031S which is tetraglycidyl ether of tetrakis (p-hydroxyphenyl) ethane, and triglycidyl ether of glycerin “Denacol” EX-314 (manufactured by Nagase Kasei Kogyo Co., Ltd.), “Denacol” EX-411 (manufactured by Nagase Kasei Kogyo Co., Ltd.), which is a tetraglycidyl ether of pentaerythritol, and the like.
　グリシジルアミンの具体例としては、ジグリシジルアニリン、テトラグリシジルジアミノジフェニルメタンである“スミエポキシ”ＥＬＭ４３４（住友化学工業株式会社製）、テトラグリシジル－ｍ－キシリレンジアミンであるＴＥＴＲＡＤ(登録商標、以下同じ)－Ｘ（三菱ガス化学株式会社製）などを挙げることができ、樹脂の伸度を著しく損なわない範囲で使用できる。 Specific examples of glycidylamine include diglycidylaniline, “Sumiepoxy” ELM434 (manufactured by Sumitomo Chemical Co., Ltd.), which is tetraglycidyldiaminodiphenylmethane, and TETRAD (registered trademark, the same applies hereinafter) —tetraglycidyl-m-xylylenediamine— X (manufactured by Mitsubishi Gas Chemical Co., Inc.) can be used, and the resin can be used within a range that does not significantly impair the elongation of the resin.
　さらに、グリシジルエーテルとグリシジルアミンの両構造を併せ持つエポキシ樹脂として、トリグリシジル－ｍ－アミノフェノールである“スミエポキシ”ＥＬＭ１２０（住友化学工業株式会社製）、およびトリグリシジル－ｐ－アミノフェノールである“アラルダイト”ＭＹ０５１０（チバガイギー社製）を挙げることができ、樹脂の伸度を著しく損なわない範囲で使用できる。 Furthermore, as epoxy resins having both glycidyl ether and glycidyl amine structures, “Sumiepoxy” ELM120 (manufactured by Sumitomo Chemical Co., Ltd.), which is triglycidyl-m-aminophenol, and “Araldite, which is triglycidyl-p-aminophenol” "MY0510 (manufactured by Ciba-Geigy Corporation) can be mentioned, and it can be used within a range that does not significantly impair the elongation of the resin.
　グリシジルエステルの具体例としては、フタル酸ジグリシジルエステル、テレフタル酸ジグリシジルエステル、ダイマー酸ジグリシジルエステルなどを挙げることができる。 Specific examples of the glycidyl ester include phthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, and dimer acid diglycidyl ester.
　さらに、これら以外のグリシジル基を有するエポキシ樹脂として、トリグリシジルイソシアヌレートを挙げることができる。 Furthermore, triglycidyl isocyanurate can be mentioned as an epoxy resin having a glycidyl group other than these.
　分子内に複数の２重結合を有する化合物を酸化して得られるエポキシ樹脂としては、エポキシシクロヘキサン環を有するエポキシ樹脂が挙げられ、具体例としては、ユニオン・カーバイド社のＥＲＬ－４２０６、ＥＲＬ－４２２１、ＥＲＬ－４２３４などを挙げることができる。さらにエポキシ化大豆油なども挙げることができる。 Examples of the epoxy resin obtained by oxidizing a compound having a plurality of double bonds in the molecule include epoxy resins having an epoxycyclohexane ring. Specific examples thereof include ERL-4206 and ERL-4221 of Union Carbide. , ERL-4234, and the like. Furthermore, epoxidized soybean oil can also be mentioned.
　これらエポキシ樹脂の中でも、ビフェニル、ナフタレン、フルオレン、ジシクロペンタジエン、およびオキサゾリドン環から選ばれる少なくとも１つの骨格を有する１種以上のエポキシ樹脂を含むことが好ましい。かかるエポキシ樹脂を１種以上含むことにより、カーボンナノファイバーとの相乗効果により力学特性が著しく向上し、樹脂硬化物の耐熱性も向上できる。 Among these epoxy resins, it is preferable to include one or more epoxy resins having at least one skeleton selected from biphenyl, naphthalene, fluorene, dicyclopentadiene, and an oxazolidone ring. By including one or more of such epoxy resins, the mechanical properties are remarkably improved by the synergistic effect with the carbon nanofibers, and the heat resistance of the cured resin can also be improved.
　ビフェニル骨格を有するエポキシ樹脂の市販品としては、例えば“エピコート”ＹＸ４０００、ＹＸ４０００Ｈ、ＹＬ６１２１（以上、ジャパンエポキシレジン株式会社製）、ＮＣ３０００、ＮＣ３０００Ｈ（以上、日本化薬株式会社製）などを挙げることができる。 Examples of commercially available epoxy resins having a biphenyl skeleton include “Epicoat” YX4000, YX4000H, YL6121 (above, Japan Epoxy Resin Co., Ltd.), NC3000, NC3000H (above, Nippon Kayaku Co., Ltd.). it can.
　ナフタレン骨格を有するエポキシ樹脂の市販品としては、“エピクロン”ＨＰ４０３２、ＨＰ４０３２Ｄ、Ｈ４０３２Ｈ、ＥＸＡ４７５０、ＥＸＡ４７００、ＥＸＡ４７０１（以上、大日本インキ工業株式会社製）、ＮＣ７０００Ｌ、ＮＣ７３００Ｌ（以上、日本化薬株式会社製）などが挙げられる。 Commercially available epoxy resins having a naphthalene skeleton include “Epiclon” HP4032, HP4032D, H4032H, EXA4750, EXA4700, EXA4701 (above, manufactured by Dainippon Ink Industries, Ltd.), NC7000L, NC7300L (above, manufactured by Nippon Kayaku Co., Ltd.) ) And the like.
　フルオレン骨格を有するエポキシ樹脂の市販品としては、“エポン(登録商標、以下同じ)”　ＨＰＴレジン１０７９（シェル社製）、“オグソール(登録商標、以下同じ)”ＰＧ、ＥＧ（以上、ナガセケムテックス株式会社製）などを挙げることができる。 Commercially available epoxy resins having a fluorene skeleton include “Epon (registered trademark, the same shall apply hereinafter)”, HPT resin 1079 (manufactured by Shell), “Ogsol (registered trademark, same shall apply hereinafter)” PG, EG (hereinafter referred to as Nagase ChemteX) And the like).
　ジシクロペンタジエン骨格を有するエポキシ樹脂の市販品としては、“エピクロン”ＨＰ７２００Ｌ、ＨＰ７２００、ＨＰ７２００Ｈ、ＨＰ７２００ＨＨ（以上、大日本インキ化学工業株式会社製）、ＸＤ－１０００－Ｌ、ＸＤ－１０００－２Ｌ（以上、日本化薬株式会社製）、“Ｔａｃｔｉｘ(登録商標、以下同じ)”５５６（Ｈｕｎｔｓｍａｎ社製）などを挙げることができる。 Commercially available epoxy resins having a dicyclopentadiene skeleton include “Epiclon” HP7200L, HP7200, HP7200H, HP7200HH (above, manufactured by Dainippon Ink & Chemicals, Inc.), XD-1000-L, XD-1000-2L (above , Nippon Kayaku Co., Ltd.), “Tactix (registered trademark, the same applies hereinafter)” 556 (manufactured by Huntsman), and the like.
　オキサゾリドン環骨格を有するエポキシ樹脂の市販品としては、“アラルダイト”ＡＥＲ４１５２、ＸＡＣ４１５１（以上、旭化成エポキシ株式会社製）などを挙げることができる。 Examples of commercially available epoxy resins having an oxazolidone ring skeleton include “Araldite” AER4152, XAC4151, and the like, manufactured by Asahi Kasei Epoxy Corporation.
　また、これら樹脂をブレンドしたものなども使用できる。例えば“アラルダイト　ＬＹ５０５２”（Ｈｕｎｔｓｍａｎ社製）等がある。 Also, a blend of these resins can be used. For example, there is “Araldite LY5052” (manufactured by Huntsman).
　本発明において、硬化剤を用いてもよい。硬化剤とは、熱硬化性樹脂との共存下で硬化反応をもたらすものであり、一般的な硬化剤のみならず、開始剤、触媒、硬化促進剤、硬化助剤、およびこれらの組み合わせを含んでもよい。具体的には、硬化剤としては、４，４’-ジアミノジフェニルメタン、４，４’－ジアミノジフェニルスルホン、３，３’－ジアミノジフェニルスルホン、ｍ－フェニレンジアミン、ｍ－キシリレンジアミンのような活性水素を有する芳香族アミン、ジエチレントリアミン、トリエチレンテトラミン、イソホロンジアミン、ビス（アミノメチル）ノルボルナン、ビス（４－アミノシクロヘキシル）メタン、ポリエチレンイミンのダイマー酸エステルのような活性水素を有する脂肪族アミン、これらの活性水素を有するアミンにエポキシ化合物、アクリロニトリル、フェノールとホルムアルデヒド、チオ尿素などの化合物を反応させて得られる変性アミン、ジメチルアニリン、ジメチルベンジルアミン、２，４，６－トリス（ジメチルアミノメチル）フェノールや１－置換イミダゾールのような活性水素を持たない第三アミン、ジシアンジアミド、テトラメチルグアニジン、ヘキサヒドロフタル酸無水物、テトラヒドロフタル酸無水物、メチルヘキサヒドロフタル酸無水物、メチルナジック酸無水物のようなカルボン酸無水物、アジピン酸ヒドラジドやナフタレンジカルボン酸ヒドラジドのようなポリカルボン酸ヒドラジド、ノボラック樹脂などのポリフェノール化合物、チオグリコール酸とポリオールのエステルのようなポリメルカプタン、三フッ化ホウ素エチルアミン錯体のようなルイス酸錯体、芳香族スルホニウム塩などが挙げられるが、特にこれに限定されるものではない。 In the present invention, a curing agent may be used. Curing agents bring about a curing reaction in the presence of thermosetting resins and include not only general curing agents but also initiators, catalysts, curing accelerators, curing aids, and combinations thereof. But you can. Specifically, the curing agent includes activities such as 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, m-phenylenediamine, and m-xylylenediamine. Aromatic amines having hydrogen, aliphatic amines having active hydrogen such as dimer acid ester of diethylenetriamine, diethylenetriamine, triethylenetetramine, isophoronediamine, bis (aminomethyl) norbornane, bis (4-aminocyclohexyl) methane, polyethyleneimine, and the like Modified amines obtained by reacting an amine having active hydrogen with an epoxy compound, acrylonitrile, a compound such as phenol and formaldehyde, thiourea, dimethylaniline, dimethylbenzylamine, 2,4,6-tris (dimethylaminomethyl) E) Tertiary amines such as phenol and 1-substituted imidazole that do not have active hydrogen, dicyandiamide, tetramethylguanidine, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic acid Carboxylic anhydrides such as anhydrides, polycarboxylic acid hydrazides such as adipic acid hydrazide and naphthalenedicarboxylic acid hydrazide, polyphenol compounds such as novolak resins, polymercaptans such as esters of thioglycolic acid and polyols, boron trifluoride Examples include Lewis acid complexes such as ethylamine complexes and aromatic sulfonium salts, but are not particularly limited thereto.
　これらの硬化剤には、硬化活性を高めるために適宜硬化助剤を組み合わせることができる。好ましい例としては、ジシアンジアミドに、３－フェニル－１,１－ジメチル尿素、３－（３，４－ジクロロフェニル）－１，１－ジメチル尿素（ＤＣＭＵ）、３－（３－クロロ－４－メチルフェニル）－１，１－ジメチル尿素、２，４－ビス（３，３－ジメチルウレイド）トルエンのような尿素誘導体を硬化助剤として組み合わせる例、カルボン酸無水物やノボラック樹脂に第三アミンを硬化助剤として組み合わせる例などがあげられる。硬化助剤として使用される化合物は、単独でもエポキシ樹脂を硬化させる能力を持つものが好ましい。 These curing agents can be combined with a curing aid as appropriate in order to increase the curing activity. Preferred examples include dicyandiamide, 3-phenyl-1,1-dimethylurea, 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU), 3- (3-chloro-4-methylphenyl). ) Examples of combining urea derivatives such as 1,1-dimethylurea and 2,4-bis (3,3-dimethylureido) toluene as curing aids, tertiary amines on carboxylic anhydrides and novolac resins Examples of combinations as agents are given. The compound used as a curing aid is preferably a compound having the ability to cure an epoxy resin alone.
　また、熱可塑性樹脂は、特に限定されるものではなく、いずれの熱可塑性樹脂も好適に使用することができる。具体的には、ポリエチレン樹脂、ポリプロピレン樹脂、ポリスチレン樹脂、ポリビニルアセテート樹脂、アクリロニトリル－ブタジエン－スチレン（ＡＢＳ）樹脂、ポリ（メチルメタクリレート）樹脂、ポリアミド樹脂、ポリカーボネート樹脂、ポリブチレンテレフタレート樹脂、ポリエチレンテレフタレート樹脂、ポリフェニレンサルファイド樹脂、ポリエーテルエーテルケトン樹脂、ポリイミド樹脂、ポリアミドイミド樹脂、ポリビニルアルコール樹脂などを使用することができる。 Further, the thermoplastic resin is not particularly limited, and any thermoplastic resin can be suitably used. Specifically, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl acetate resin, acrylonitrile-butadiene-styrene (ABS) resin, poly (methyl methacrylate) resin, polyamide resin, polycarbonate resin, polybutylene terephthalate resin, polyethylene terephthalate resin, Polyphenylene sulfide resin, polyether ether ketone resin, polyimide resin, polyamideimide resin, polyvinyl alcohol resin and the like can be used.
　本発明の２層カーボンナノチューブ含有複合体は、このような樹脂に対して２層カーボンナノチューブを０．００１ｗｔ％（重量％）以上１０ｗｔ％以下で含む複合体である。好ましくは０．００５ｗｔ％以上５ｗｔ％以下で含む。これにより、２層カーボンナノチューブ含有複合体の樹脂特性を好適に向上させることができる。 The double-walled carbon nanotube-containing composite of the present invention is a composite containing 0.001 wt% (wt%) to 10 wt% of double-walled carbon nanotubes with respect to such a resin. Preferably, it is contained at 0.005 wt% or more and 5 wt% or less. Thereby, the resin characteristic of a double-walled carbon nanotube containing composite can be improved suitably.
　図１は、本発明の実施の形態にかかる２層カーボンナノチューブ含有複合体に対するラマン分光分析を説明するための図である。２層カーボンナノチューブ含有複合体に対して、所定の荷重を加えた状態でラマン分光分析し、歪みと、Ｇ’バンドシフトとの関係を示すグラフを取得する。この場合、次の様な操作を行って歪みに対するＧ’バンドシフトを取得する。 FIG. 1 is a diagram for explaining Raman spectroscopic analysis for a double-walled carbon nanotube-containing composite according to an embodiment of the present invention. The double-walled carbon nanotube-containing composite is subjected to Raman spectroscopic analysis with a predetermined load applied, and a graph showing the relationship between strain and G ′ band shift is obtained. In this case, the G ′ band shift with respect to the distortion is acquired by performing the following operation.
　まず、２層カーボンナノチューブと樹脂の複合体１を基材１０の上に固定し、基材１０に応力を掛けて複合体１を歪ませる（図１参照）。このとき、基材１０に加える応力は、シート状の基材１０において、表面（図中上面）および裏面（図中下面）から各表面を押圧する方向であって、裏面側における加圧位置が、表面側における加圧位置より中央部に位置するようにそれぞれ加えられる。この基材１０の歪みにより、複合体１は、表面側が凸となる弧状をなして歪む。この時の歪み（割合）を歪みゲージで測定し、グラフの横軸にプロットする。 First, the composite 1 of the double-walled carbon nanotube and the resin is fixed on the base 10 and stress is applied to the base 10 to distort the composite 1 (see FIG. 1). At this time, the stress applied to the base material 10 is a direction in which each surface is pressed from the front surface (upper surface in the figure) and the back surface (lower surface in the figure) in the sheet-like base material 10, and the pressing position on the back surface side is These are applied so as to be located in the center portion from the pressurizing position on the surface side. Due to the distortion of the base material 10, the composite 1 is distorted in an arc shape having a convex surface side. The strain (ratio) at this time is measured with a strain gauge and plotted on the horizontal axis of the graph.
　ラマン分光分析は、複合体１が歪んだ状態で波長５１４ｎｍまたは６３３ｎｍのレーザーを用いて行う。ラマン分光分析では、照射されたレーザーに応じた複合体１からの散乱光を検出する。このとき、約２６００ｃｍ－１付近に２層カーボンナノチューブ由来のＧ’バンドが出現する。ここで、内層側カーボンナノチューブ由来のＧ’バンドは２５９０ｃｍ－１付近に検出され、外層側カーボンナノチューブ由来のＧ’バンドは２６３０ｃｍ－１付近に検出される。歪みとＧ’バンドシフトとの関係を示すグラフにおいて、歪みを加圧率（Strain（％））として横軸にプロットし、内層、外層それぞれのＧ’バンドシフトを（Ｇ’－Band　frequency（ｃｍ－１））として縦軸にプロットする。 The Raman spectroscopic analysis is performed using a laser having a wavelength of 514 nm or 633 nm in a state where the composite 1 is distorted. In the Raman spectroscopic analysis, scattered light from the complex 1 corresponding to the irradiated laser is detected. At this time, a G ′ band derived from a double-walled carbon nanotube appears around 2600 cm −1 . Here, the G ′ band derived from the inner layer side carbon nanotube is detected in the vicinity of 2590 cm −1 , and the G ′ band derived from the outer layer side carbon nanotube is detected in the vicinity of 2630 cm −1 . In the graph showing the relationship between the strain and the G ′ band shift, the strain is plotted on the horizontal axis as the pressing rate (Strain (%)), and the G ′ band shift of each of the inner layer and the outer layer is expressed by (G′−Band frequency (cm -1 )) is plotted on the vertical axis.
　本発明にかかる２層カーボンナノチューブ含有複合体は、引張歪み範囲が０％～０．４％においてグラフを作製したときに、引張歪みに対するＧ’バンドシフト（プロット）が、内層側カーボンナノチューブ、外層側カーボンナノチューブにおいてそれぞれ近似直線近傍に位置する。近似直線の作製法は、最小二乗法が好ましい。また、このような直線を作製したときに、それぞれの傾き（ｃｍ－１／％）を求めることができる。この傾きの値を用いて、外層側カーボンナノチューブの傾きに対する内層側カーボンナノチューブの傾きの比（内層の傾き／外層の傾き）の値を求めたとき、本発明にかかる複合体は、０．５以上１．５以下となる。さらに好ましくは内層の傾き／外層の傾きの値が、０．８以上１．２以下である。内層の傾き／外層の傾きの値が、０．５以上１．５以下であることは、２層カーボンナノチューブにおいて内層と外層との応力が伝搬していることを示している。外層に加えられた応力が内層に応力伝搬している場合には、同じようなＧ’バンドのシフトが起こり、この傾きが平行に近くなる。この傾きが規定範囲を超えると外層に加わった力が内層へ伝搬されていないことを示す。２層カーボンナノチューブの外層が樹脂との親和性を発揮し、外部から加わった力が樹脂－外層－内層と応力伝搬することで、内層の非常に高品質なカーボンナノチューブ自身の高機械強度を発揮するため、複合体として非常に高い機械強度を発揮するのである。 The composite containing a double-walled carbon nanotube according to the present invention has a G ′ band shift (plot) with respect to the tensile strain when the graph is prepared in a tensile strain range of 0% to 0.4%. Each of the side carbon nanotubes is located near the approximate straight line. The method of producing the approximate straight line is preferably the least square method. In addition, when such a straight line is produced, the respective inclinations (cm −1 /%) can be obtained. Using this slope value, when the ratio of the slope of the inner carbon nanotube to the slope of the outer carbon nanotube (the slope of the inner layer / the slope of the outer layer) was determined, the composite according to the present invention was 0.5 It is 1.5 or less. More preferably, the value of the inner layer inclination / outer layer inclination is 0.8 or more and 1.2 or less. The value of the inclination of the inner layer / the inclination of the outer layer is not less than 0.5 and not more than 1.5, indicating that the stress between the inner layer and the outer layer propagates in the double-walled carbon nanotube. When the stress applied to the outer layer propagates to the inner layer, the same G ′ band shift occurs, and this inclination becomes nearly parallel. If this inclination exceeds the specified range, it indicates that the force applied to the outer layer is not propagated to the inner layer. The outer layer of the double-walled carbon nanotube exhibits affinity with the resin, and the externally applied force propagates stress between the resin, the outer layer, and the inner layer, thereby demonstrating the high mechanical strength of the very high-quality carbon nanotube of the inner layer itself. Therefore, it exhibits a very high mechanical strength as a composite.
　本発明にかかる２層カーボンナノチューブ含有複合体は、この外層に由来する傾きの絶対値が１０ｃｍ－１／％以上５０ｃｍ－１／％以下であることが好ましく、１５ｃｍ－１／％以上３０ｃｍ－１／％以下であることがさらに好ましい。この傾きが規定範囲内であるとは、２層カーボンナノチューブ含有複合体において、マトリックス樹脂と２層カーボンナノチューブの外層との応力が伝搬していること、および２層カーボンナノチューブの弾性率が高いことを示す。 In the double-walled carbon nanotube-containing composite according to the present invention, the absolute value of the inclination derived from the outer layer is preferably 10 cm −1 /% to 50 cm −1 /%, and preferably 15 cm −1 /% to 30 cm −1. /% Or less is more preferable. The inclination within the specified range means that in the double-walled carbon nanotube-containing composite, the stress propagates between the matrix resin and the outer layer of the double-walled carbon nanotube, and the elastic modulus of the double-walled carbon nanotube is high. Indicates.
　ここで、本発明で好ましく用いられる２層カーボンナノチューブの製造方法は、例えば以下のように製造される。 Here, the method for producing a double-walled carbon nanotube preferably used in the present invention is produced, for example, as follows.
　縦型流動床型反応器中、反応器の水平断面方向全面に、マグネシアに鉄を担持した粉末状の触媒による流動床を形成し、該反応器内にメタンを鉛直方向に流通させ、該メタンを５００～１２００℃で、該触媒に接触させ、カーボンナノチューブを製造した後、得られたカーボンナノチューブを精製処理することにより得られる。 In a vertical fluidized bed reactor, a fluidized bed made of powdered catalyst with iron supported on magnesia is formed on the entire horizontal cross-sectional direction of the reactor, and methane is circulated in the vertical direction in the reactor. Is obtained by contacting the catalyst at 500 to 1200 ° C. with the catalyst to produce carbon nanotubes, and then purifying the obtained carbon nanotubes.
　触媒である鉄を、担体であるマグネシアに担持させることにより、鉄の粒径をコントロールしやすく、また高密度で鉄が存在しても高温下でシンタリングが起こりにくい。そのため、高品質なカーボンナノチューブを効率よく多量に合成することができる。さらに、マグネシアは酸性水溶液に溶けるので、酸性水溶液で処理するだけでマグネシアおよび鉄の両者を取り除くこともできるため、精製工程を簡便化することができる。 By supporting iron, which is a catalyst, on magnesia, which is a carrier, it is easy to control the particle size of iron, and even when iron is present at high density, sintering is unlikely to occur at high temperatures. Therefore, a large amount of high-quality carbon nanotubes can be efficiently synthesized. Furthermore, since magnesia dissolves in an acidic aqueous solution, both the magnesia and iron can be removed simply by treating with an acidic aqueous solution, so that the purification process can be simplified.
　マグネシアは、市販品を使用しても良いし、合成したものを使用しても良い。マグネシアの好ましい製法としては、金属マグネシウムを空気中で加熱する、水酸化マグネシウムを８５０℃以上に加熱する、または炭酸水酸化マグネシウム３ＭｇＣＯ３・Ｍｇ（ＯＨ）２・３Ｈ２Ｏを９５０℃以上に加熱する等の方法がある。 As magnesia, a commercially available product may be used, or a synthesized product may be used. As a preferable production method of magnesia, magnesium metal is heated in air, magnesium hydroxide is heated to 850 ° C. or higher, or magnesium carbonate 3MgCO 3 .Mg (OH) 2 .3H 2 O is heated to 950 ° C. or higher. There are ways to do it.
　マグネシアの中でも軽質マグネシアが好ましい。軽質マグネシアとは、かさ密度が小さいマグネシアであり、具体的には０．２０ｇ／ｍＬ以下であることが好ましく、０．０５～０．１６（ｇ／ｍＬ）であることが触媒の流動性の点から好ましい。かさ密度とは単位かさ体積あたりの粉体質量のことである。以下にかさ密度の測定方法を示す。粉体のかさ密度は、測定時の温度および湿度に影響されることがある。ここで言うかさ密度は、温度２０±１０℃、湿度６０±１０％で測定したときの値である。測定は、５０ｍＬメスシリンダーを測定容器として用い、メスシリンダーの底を軽く叩きながら、予め定めた容積を占めるように粉末を加える。かさ密度の測定に際しては１０ｍＬの粉末を加えるものとするが、測定可能な試料が不足している場合には、可能な限り１０ｍＬに近い量で行う。その後、メスシリンダーの底を床面１ｃｍの高さから落とすことを２０回繰り返した後、目視にて粉末が占める容積値の変化率が±０．２ｍＬ（試料が少ない場合は±２％）以内であることを確認し、詰める操作を終了する。もし容積値に目視にて±０．２ｍＬ（±２％）を越える変化があれば、メスシリンダーの底を軽く叩きながら粉末を追加し、再度メスシリンダーの底を床面１ｃｍの高さから落とすことを２０回繰り返し、目視にて粉末が占める容積値に±０．２ｍＬ（±２％）を越える変化がないことを確認して操作を終了する。上記の方法で詰めた一定量の粉末の重量を求めることを３回繰り返し、その平均重量を粉末が占める容積で割った値（＝重量（ｇ）／体積（ｍＬ））を粉末のかさ密度とする。 Of magnesia, light magnesia is preferable. Light magnesia is magnesia having a low bulk density, specifically 0.20 g / mL or less, preferably 0.05 to 0.16 (g / mL). It is preferable from the point. Bulk density is the mass of powder per unit bulk volume. The bulk density measurement method is shown below. The bulk density of the powder may be affected by the temperature and humidity at the time of measurement. The bulk density referred to here is a value measured at a temperature of 20 ± 10 ° C. and a humidity of 60 ± 10%. For the measurement, a 50 mL graduated cylinder is used as a measurement container, and the powder is added so as to occupy a predetermined volume while tapping the bottom of the graduated cylinder. When measuring the bulk density, 10 mL of powder is added. However, if there is a shortage of measurable samples, the amount is as close to 10 mL as possible. Then, after dropping the bottom of the graduated cylinder from the height of 1 cm on the floor 20 times, the change rate of the volume value occupied by the powder is within ± 0.2 mL (± 2% when there are few samples). Is confirmed, and the stuffing operation is terminated. If there is a visual change in the volume value that exceeds ± 0.2 mL (± 2%), add the powder while tapping the bottom of the graduated cylinder, and drop the graduated cylinder from the height of 1 cm on the floor again. This is repeated 20 times, and it is confirmed that there is no change exceeding ± 0.2 mL (± 2%) in the volume value occupied by the powder, and the operation is finished. The determination of the weight of a certain amount of powder packed by the above method is repeated three times, and the value obtained by dividing the average weight by the volume occupied by the powder (= weight (g) / volume (mL)) is the bulk density of the powder. To do.
　担体に担持する鉄は、０価の状態とは限らない。反応中は０価の金属状態になっていると推定できるが、広く鉄を含む化合物または鉄種でよい。例えば、ギ酸鉄、酢酸鉄、トリフルオロ酢酸鉄、クエン酸アンモニウム鉄、硝酸鉄、硫酸鉄、ハロゲン化物鉄などの有機塩または無機塩、エチレンジアミン４酢酸錯体やアセチルアセトナート錯体のような錯塩などが用いられる。また鉄は微粒子であることが好ましい。微粒子の粒径は０．５～１０ｎｍであることが好ましい。鉄が微粒子であると外径の細いカーボンナノチューブが生成しやすい。 The iron carried on the carrier is not always in a zero-valent state. Although it can be estimated that the metal is in a zero-valent state during the reaction, it may be a compound containing iron or an iron species. For example, organic salts or inorganic salts such as iron formate, iron acetate, iron trifluoroacetate, iron iron citrate, iron nitrate, iron sulfate, and iron halide, complex salts such as ethylenediaminetetraacetic acid complex and acetylacetonate complex, etc. Used. Iron is preferably fine particles. The particle diameter of the fine particles is preferably 0.5 to 10 nm. When iron is a fine particle, a carbon nanotube with a small outer diameter is likely to be generated.
　カーボンナノチューブ製造用触媒の製造方法は、特に限定されない。例えば、鉄の金属塩を溶解させた非水溶液中（例えばメタノール溶液）又は水溶液中に、マグネシアを含浸し、充分に分散混合した後、乾燥させる。またその後、大気中あるいは窒素、アルゴン、ヘリウムなどの不活性ガス中あるいは真空中において高温（１００℃～６００℃）で加熱してもよい（含浸法）。あるいは鉄の金属塩を溶解させた水溶液中に、マグネシアなどの担体を含浸して十分に分散混合し、加熱加圧下（１００℃～２００℃、４～１５（ｋｇｆ／ｃｍ２））で反応させた後に、大気中あるいは窒素などの不活性ガス中で、高温（４００℃～７００℃）で加熱しても良い（水熱法）。水熱法によるカーボンナノチューブ製造用触媒の製造方法は、鉄化合物とＭｇ化合物とを水中で混合撹拌し、該混合液を加熱、加圧による水熱反応で触媒前駆体が得られ、該触媒前駆体を特定の温度で加熱することで得られる。水熱反応を行うことで、鉄化合物とＭｇ化合物とがそれぞれ加水分解され、脱水重縮合を経由して複合水酸化物となる。これにより鉄が水酸化Ｍｇ中に高度に分散された状態の触媒前駆体になる。 The method for producing the carbon nanotube production catalyst is not particularly limited. For example, magnesia is impregnated in a non-aqueous solution (for example, a methanol solution) or an aqueous solution in which a metal salt of iron is dissolved, sufficiently dispersed and mixed, and then dried. Thereafter, it may be heated at a high temperature (100 ° C. to 600 ° C.) in the atmosphere or in an inert gas such as nitrogen, argon or helium or in vacuum (impregnation method). Alternatively, a carrier such as magnesia is impregnated in an aqueous solution in which an iron metal salt is dissolved, sufficiently dispersed and mixed, and reacted under heat and pressure (100 ° C. to 200 ° C., 4 to 15 (kgf / cm 2 )). Then, it may be heated at a high temperature (400 ° C. to 700 ° C.) in the air or in an inert gas such as nitrogen (hydrothermal method). A catalyst for carbon nanotube production by a hydrothermal method is prepared by mixing and stirring an iron compound and an Mg compound in water, heating the mixture, and hydrothermal reaction by pressurization to obtain a catalyst precursor. Obtained by heating the body at a specific temperature. By carrying out the hydrothermal reaction, the iron compound and the Mg compound are each hydrolyzed to become a composite hydroxide via dehydration polycondensation. This becomes a catalyst precursor in a state where iron is highly dispersed in Mg hydroxide.
　Ｍｇ化合物としては硝酸塩、亜硝酸塩、硫酸塩、硫酸アンモニウム塩、炭酸塩、酢酸塩、クエン酸塩、酸化物および水酸化物が好ましく、酸化物がより好ましい。 As the Mg compound, nitrate, nitrite, sulfate, ammonium sulfate, carbonate, acetate, citrate, oxide and hydroxide are preferable, and oxide is more preferable.
　鉄化合物とＭｇ化合物との使用量は、鉄化合物中の鉄成分量が、Ｍｇ化合物のＭｇＯ換算量に対して、０．１ｗｔ％以上１ｗｔ％以下となるよう混合しておくことが２層を含有する比較的細いカーボンナノチューブを製造しやすい点で好ましく、より好ましくは０．２ｗｔ％以上０．６ｗｔ％以下の範囲である。上記範囲より鉄成分量が多い場合には、担持される鉄粒子の粒子径が大きくなり、得られるカーボンナノチューブも太くなる傾向にあるため、比較的細いカーボンナノチューブを製造しようとする場合には注意を要するが、水熱反応後、加熱して薄片状ＭｇＯ触媒を製造する場合には、直接ＭｇＯに鉄化合物を担持する場合に比較して鉄粒子の粒度のバラツキも少なく、比較的直径の揃った２層カーボンナノチューブを得ることができる。 The amount of the iron compound and the Mg compound used may be mixed in two layers so that the amount of the iron component in the iron compound is 0.1 wt% or more and 1 wt% or less with respect to the MgO equivalent amount of the Mg compound. It is preferable in terms of easy production of the contained relatively thin carbon nanotube, and more preferably in the range of 0.2 wt% or more and 0.6 wt% or less. When the amount of iron component is larger than the above range, the particle size of the supported iron particles increases, and the resulting carbon nanotubes also tend to be thick, so be careful when trying to produce relatively thin carbon nanotubes However, when a flaky MgO catalyst is produced by heating after a hydrothermal reaction, there is less variation in the particle size of the iron particles compared to the case where the iron compound is directly supported on MgO, and the diameters are relatively uniform. In addition, a double-walled carbon nanotube can be obtained.
　また水とＭｇ化合物とはモル比で４：１～１００：１で混合することが好ましく、より好ましくは９：１～５０：１であり、更に好ましくは９：１～３０：１である。 The water and Mg compound are preferably mixed at a molar ratio of 4: 1 to 100: 1, more preferably 9: 1 to 50: 1, and further preferably 9: 1 to 30: 1.
　尚、鉄化合物とＭｇ化合物とはあらかじめ混合、濃縮乾固したものを水中で混合撹拌して水熱反応を行っても良いが、工程を簡略化するために、鉄化合物とＭｇ化合物とを直接水中に加えて、水熱反応に供することが好ましい。水熱反応は加熱、加圧下で行われるが、オートクレーブなどの耐圧容器中で懸濁状態を含む混合水を１００℃～２５０℃の範囲で加熱し、自生圧を発生させることが好ましい。加熱温度は１００℃～２００℃の範囲がより好ましい。尚、不活性ガスを加えて圧力をかけてもかまわない。カーボンナノチューブ製造用触媒の製造方法において、水熱反応時の加熱時間は加熱温度と密接に関係しており、通常は３０分～１０時間程度で行われ、温度が高いほど短時間で水熱反応は短くてすむ。例えば２５０℃で行う場合は３０分～２時間が好ましく、１００℃で行う場合は２時間～１０時間が好ましい。 The iron compound and Mg compound may be mixed and stirred in water after mixing, concentrating and drying in advance, and the hydrothermal reaction may be carried out. However, in order to simplify the process, the iron compound and Mg compound are directly combined. In addition to water, it is preferably subjected to a hydrothermal reaction. The hydrothermal reaction is carried out under heating and pressure, but it is preferable to generate a self-generated pressure by heating the mixed water containing the suspension in a pressure vessel such as an autoclave in the range of 100 ° C to 250 ° C. The heating temperature is more preferably in the range of 100 ° C to 200 ° C. It is also possible to apply pressure by adding an inert gas. In the method for producing a catalyst for producing carbon nanotubes, the heating time at the time of hydrothermal reaction is closely related to the heating temperature, usually 30 minutes to 10 hours, and the higher the temperature, the shorter the hydrothermal reaction. Is short. For example, when it is performed at 250 ° C., 30 minutes to 2 hours are preferable, and when it is performed at 100 ° C., 2 hours to 10 hours are preferable.
　水熱反応後、触媒前駆体は、スラリー状の懸濁液になっている。回収方法はこだわらないが、好ましくは濾過あるいは遠心分離することにより、容易に触媒前駆体を回収することができる。より好ましくは濾別であり、吸引濾過または自然濾過のどちらで行ってもかまわない。 After the hydrothermal reaction, the catalyst precursor is a slurry suspension. The recovery method is not particularly limited, but the catalyst precursor can be easily recovered preferably by filtration or centrifugation. More preferably, filtration is performed, and either suction filtration or natural filtration may be performed.
　水熱処理後、固液分離した触媒前駆体は、鉄とＭｇとの複合水酸化物であり、加熱することにより鉄とＭｇとの複合酸化物となる。加熱処理は大気または窒素、アルゴン、ヘリウムなどの不活性ガス中で行われ、４００℃～１０００℃の範囲で加熱することが好ましく、４００℃～７００℃の範囲がさらに好ましい。加熱時間は１時間～５時間の範囲で行うことが好ましい。加熱前の触媒前駆体は、水酸化Ｍｇが主体であるため、薄片状の１次構造をとっている。加熱温度が高すぎると脱水の際に焼結が起こり、薄片状の２次構造を維持できず、球形あるいは立方体、直方体の構造をとってしまう。これにより、鉄がＭｇＯ内部に取り込まれ、カーボンナノチューブの合成に際しては不効率となる可能性がある。 After the hydrothermal treatment, the catalyst precursor subjected to solid-liquid separation is a composite hydroxide of iron and Mg, and when heated, becomes a composite oxide of iron and Mg. The heat treatment is performed in the atmosphere or in an inert gas such as nitrogen, argon, helium, etc., and is preferably heated in the range of 400 ° C. to 1000 ° C., more preferably in the range of 400 ° C. to 700 ° C. The heating time is preferably in the range of 1 to 5 hours. Since the catalyst precursor before heating is mainly composed of Mg hydroxide, it has a flaky primary structure. If the heating temperature is too high, sintering occurs during dehydration, and the flaky secondary structure cannot be maintained, resulting in a spherical, cubic, or cuboid structure. As a result, iron is taken into MgO, which may be inefficient when synthesizing carbon nanotubes.
　本発明において反応方式は特に限定しないが、縦型流動床型反応器を用いて反応させることが好ましい。縦型流動床型反応器とは、原料（炭素源）となるメタンが、鉛直方向（以下「縦方向」と称する場合もある）に流通するように設置された反応器である。該反応器の一方の端部から他方の端部に向けた方向にメタンが流通し、触媒層を通過する。反応器は、例えば管形状を有する反応器を好ましく用いることができる。なお、上記において、鉛直方向とは、鉛直方向に対して若干傾斜角度を有する方向も含む（例えば水平面に対し９０°±１５°、好ましくは９０°±１０°）。なお、横型（水平方向）であっても反応させることができるが、好ましいのは縦型（鉛直方向）である。なお、メタンの供給部および排出部は、必ずしも反応器の端部である必要はなく、メタンが前記方向に流通し、その流通過程で触媒層を通過すればよい。 In the present invention, the reaction system is not particularly limited, but the reaction is preferably carried out using a vertical fluidized bed reactor. The vertical fluidized bed reactor is a reactor installed so that methane as a raw material (carbon source) flows in a vertical direction (hereinafter sometimes referred to as “longitudinal direction”). Methane flows in the direction from one end of the reactor toward the other end and passes through the catalyst layer. As the reactor, for example, a reactor having a tube shape can be preferably used. In the above, the vertical direction includes a direction having a slight inclination angle with respect to the vertical direction (for example, 90 ° ± 15 °, preferably 90 ° ± 10 ° with respect to the horizontal plane). In addition, although it can be made to react even if it is a horizontal type (horizontal direction), a vertical type (vertical direction) is preferable. Note that the methane supply section and the discharge section do not necessarily have to be end portions of the reactor, and methane may flow in the above-described direction and pass through the catalyst layer in the flow process.
　図２は、本実施の形態にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブを製造するカーボンナノチューブ製造装置の構成例を示す模式図である。図２に示す合成装置１００は、メタンなどの炭素源を用いてカーボンナノチューブを合成する反応管１０１と、反応管１０１の外周に設けられ、通電により発熱し、発生した熱によって反応管１０１内を加熱する電気炉１０２と、一端が反応管１０１に連通し、反応管１０１内に炭素源を導入する導入管１０３と、導入管１０３の他端に接続し、気体状の炭素源を供給する炭素源供給部１０４ａからの炭素源の線速を制御する線速制御部１０４と、導入管１０３の中央部で分岐された側管１０３ａに接続し、移動相としてのキャリアガスを供給するキャリアガス供給部１０５ａからのキャリアガスの線速を制御する線速制御部１０５と、導入管１０３の反応管１０１側の端部に設けられ、触媒を保持する石英焼結板１０６ａを有する触媒保持部１０６と、反応管１０１内で生成されたカーボンナノチューブを回収する回収部１０７と、触媒保持部１０６の温度を計測する温度計１０８と、を備える。また、回収部１０７には、反応管１０１および回収部１０７を通過したキャリアガスなどを排出するガス排出管１０７ａが設けられている。 FIG. 2 is a schematic diagram showing a configuration example of a carbon nanotube production apparatus for producing a carbon nanotube of a double-walled carbon nanotube-containing composite according to the present embodiment. A synthesis apparatus 100 shown in FIG. 2 is provided on the outer periphery of a reaction tube 101 that synthesizes carbon nanotubes using a carbon source such as methane, and generates heat when energized. An electric furnace 102 to be heated, one end communicating with the reaction tube 101, an introduction tube 103 for introducing a carbon source into the reaction tube 101, and a carbon connected to the other end of the introduction tube 103 to supply a gaseous carbon source A carrier gas supply for supplying a carrier gas as a mobile phase connected to a linear velocity control unit 104 for controlling the linear velocity of the carbon source from the source supply unit 104a and a side pipe 103a branched at the center of the introduction pipe 103 Catalyst holding unit having a linear velocity control unit 105 that controls the linear velocity of the carrier gas from the unit 105a and a quartz sintered plate 106a that is provided at the end of the introduction tube 103 on the reaction tube 101 side and that holds the catalyst. Comprising 106, a recovery unit 107 for recovering the carbon nanotubes produced in the reaction tube 101, a thermometer 108 for measuring the temperature of the catalyst retaining section 106, a. The recovery unit 107 is provided with a gas exhaust pipe 107 a that exhausts the carrier gas and the like that has passed through the reaction tube 101 and the recovery unit 107.
　触媒は、縦型流動床型反応器中、反応器の水平断面方向全面に存在させた状態にあり、反応時には流動床を形成した状態とする。このようにすることにより、触媒とメタンを有効に接触させることができる。触媒保持部１０６では、反応管１０１の中に触媒を置く台である石英焼結板１０６ａが設置され、その上に形成された触媒層が、反応管１０１の水平断面方向全体に存在している。 The catalyst is in a state of being present in the entire horizontal cross-sectional direction of the reactor in the vertical fluidized bed reactor, and a fluidized bed is formed during the reaction. By doing in this way, a catalyst and methane can be made to contact effectively. In the catalyst holding unit 106, a quartz sintered plate 106a, which is a table for placing the catalyst, is installed in the reaction tube 101, and the catalyst layer formed thereon exists over the entire horizontal cross-sectional direction of the reaction tube 101. .
　流動床型は、触媒を連続的に供給し、反応後の触媒とカーボンナノチューブを連続的に取り出すことにより、連続的な合成が可能であり、カーボンナノチューブを効率よく得ることができ好ましい。 The fluidized bed type is preferable because continuous synthesis is possible by continuously supplying a catalyst and continuously removing the catalyst and carbon nanotubes after the reaction, and carbon nanotubes can be obtained efficiently.
　流動床型反応において、原料のメタンと触媒が均一に効率よく接触するためにカーボンナノチューブ合成反応が均一に行われ、アモルファスカーボンなどの不純物による触媒被覆が抑制され、触媒活性が長く続くと考えられる。 In the fluidized bed type reaction, since the raw material methane and the catalyst are uniformly and efficiently contacted, the carbon nanotube synthesis reaction is performed uniformly, the catalyst coating by impurities such as amorphous carbon is suppressed, and the catalyst activity is expected to continue for a long time. .
　縦型反応器とは対照的に、横型反応器は横方向（水平方向）に設置された反応器内に、石英板上に置かれた触媒が設置され、該触媒上をメタンが通過して接触、反応する態様の反応装置を指す。この場合、触媒表面ではカーボンナノチューブが生成されるが、触媒内部にはメタンが到達しないため、縦型反応器に比較して収量が少なくなる傾向にある。これに対して、縦型反応器では触媒全体に原料のメタンが接触することが可能となるため、効率的に、多量のカーボンナノチューブを合成することが可能である。反応器は耐熱性であることが好ましく、石英製、アルミナ製等の耐熱材質からなることが好ましい。 In contrast to a vertical reactor, a horizontal reactor has a laterally (horizontal) reactor in which a catalyst placed on a quartz plate is placed, and methane passes over the catalyst. It refers to a reaction device in a mode of contacting and reacting. In this case, carbon nanotubes are generated on the catalyst surface, but methane does not reach the inside of the catalyst, so that the yield tends to be lower than that of the vertical reactor. In contrast, in the vertical reactor, the raw material methane can be brought into contact with the entire catalyst, so that a large amount of carbon nanotubes can be efficiently synthesized. The reactor is preferably heat resistant and is preferably made of a heat resistant material such as quartz or alumina.
　メタンの線速は８ｃｍ／ｓｅｃ以上で流通させる。カーボンナノチューブ合成反応においては、メタンの分解効率をあげて、収率を上げるためにメタンを低線速にて流通させることが通常であったが、本発明では触媒の凝集体を従来よりも大きくしている。そのため、低線速にて加熱温度下流通させると触媒層が流動せず、メタンは触媒層の最も通りやすい箇所だけを通ってしまうという、いわゆるショートパスの問題が生じる。よって、線速は、８ｃｍ／ｓｅｃ以上、１０ｃｍ／ｓｅｃ以下が好ましい。 Methane is distributed at a linear speed of 8 cm / sec or higher. In the carbon nanotube synthesis reaction, in order to increase the decomposition efficiency of methane and increase the yield, it was usual to circulate methane at a low linear velocity. However, in the present invention, the aggregate of the catalyst is larger than the conventional one. is doing. Therefore, when flowing at a low linear velocity and at a heating temperature, the catalyst layer does not flow, and a problem of so-called short path occurs in which methane passes only through the most easily passing portion of the catalyst layer. Therefore, the linear velocity is preferably 8 cm / sec or more and 10 cm / sec or less.
　合成された２層カーボンナノチューブは、通常触媒を除去し、必要に応じ、精製や酸化処理等を経て複合体形成に供される。 The synthesized double-walled carbon nanotubes are usually removed from the catalyst and subjected to complex formation through purification, oxidation treatment or the like, if necessary.
　上述した実施の形態によれば、荷重を加えた状態でラマン分光分析した場合に得られる歪みとＧ’バンドシフトとの関係を示すグラフにおいて、外層側カーボンナノチューブに由来する直線の傾きに対する内層側カーボンナノチューブに由来する直線の傾きの比が、０．５以上１．５以下となるようにしたので、２層カーボンナノチューブと樹脂の親和性が高く、かつ高い機械強度を有する２層カーボンナノチューブ含有複合体を得ることができる。 According to the above-described embodiment, in the graph showing the relationship between the strain obtained when Raman spectroscopic analysis is performed with a load applied and the G ′ band shift, the inner layer side with respect to the slope of the straight line derived from the outer layer side carbon nanotubes Since the ratio of the slope of the straight line derived from the carbon nanotube is 0.5 or more and 1.5 or less, the double-walled carbon nanotube has high mechanical strength and high affinity between the double-walled carbon nanotube and the resin. A complex can be obtained.
　以下、実施例により本発明を具体的に説明するが、下記の実施例は例示のために示すものであって、いかなる意味においても、本発明を限定的に解釈するものとして使用してはならない。 EXAMPLES Hereinafter, the present invention will be specifically described by way of examples. However, the following examples are given for illustrative purposes and should not be used in any way as a limited interpretation of the present invention. .
＜参考例＞
[カーボンナノチューブ製造例]
（触媒調製）
　約２４．６ｇのクエン酸鉄（ＩＩＩ）アンモニウム（和光純薬工業株式会社製）をイオン交換水６．７ｋｇに溶解した。この溶液に、酸化マグネシウム（岩谷化学工業株式会社製　ＭＪ－３０）を約１０００ｇ加え、撹拌機で６０分間激しく撹拌処理した後に、得られた懸濁液を、容量が１０Ｌのオートクレーブ容器中に導入した。密閉した状態で撹拌しながら、１６０℃に加熱し６時間保持した。その後オートクレーブ容器を放冷し、容器からスラリー状の白濁物質を取り出し、過剰の水分を吸引濾過により濾別した。このときの濾取物中の含水分率は２．１６であった。さらに、濾取物を１２０℃の乾燥機中で加熱乾燥し、水分を蒸発させた。その後、得られた固形分を乳鉢で細粒化しながら、篩いを用いることによって０．８５ｍｍ～２．３６ｍｍの範囲の粒径の触媒を回収した。得られた触媒中、２．０ｍｍ～２．３６ｍｍの範囲の粒径の触媒は２７．５％含まれていた。これらの顆粒状触媒を電気炉中に導入し、大気下６００℃で３時間加熱した。また、エネルギー分散型Ｘ線分析装置（ＥＤＸ）により触媒に含まれる鉄含有量を分析した結果、触媒中の鉄含有率は０．４０ｗｔ％であった。 <Reference example>
[Examples of carbon nanotube production]
(Catalyst preparation)
About 24.6 g of iron (III) ammonium citrate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 6.7 kg of ion exchange water. About 1000 g of magnesium oxide (MJ-30 manufactured by Iwatani Chemical Industry Co., Ltd.) was added to this solution, and after vigorously stirring for 60 minutes with a stirrer, the resulting suspension was introduced into an autoclave container having a capacity of 10 L. did. While stirring in a sealed state, the mixture was heated to 160 ° C. and held for 6 hours. Thereafter, the autoclave container was allowed to cool, the slurry-like cloudy substance was taken out from the container, and excess water was separated by suction filtration. The moisture content in the filtered product at this time was 2.16. Further, the filtered product was dried by heating in a dryer at 120 ° C. to evaporate water. Thereafter, a catalyst having a particle size in the range of 0.85 mm to 2.36 mm was recovered by using a sieve while refining the obtained solid content in a mortar. The obtained catalyst contained 27.5% of a catalyst having a particle size in the range of 2.0 mm to 2.36 mm. These granular catalysts were introduced into an electric furnace and heated at 600 ° C. for 3 hours in the atmosphere. Moreover, as a result of analyzing the iron content contained in the catalyst with an energy dispersive X-ray analyzer (EDX), the iron content in the catalyst was 0.40 wt%.
（カーボンナノチューブ製造）
　図２に示した合成装置１００を用いてカーボンナノチューブの合成を行った。反応管１０１には、内径７５ｍｍ、中心軸方向の長さ１１００ｍｍである円筒形石英管を用いた。また、反応管１０１を任意温度に保持できるように、反応管１０１の円周を取り囲む円環状をなす電気炉１０２を３台配置した。 (Production of carbon nanotubes)
Carbon nanotubes were synthesized using the synthesis apparatus 100 shown in FIG. As the reaction tube 101, a cylindrical quartz tube having an inner diameter of 75 mm and a length in the central axis direction of 1100 mm was used. Further, three electric furnaces 102 having an annular shape surrounding the circumference of the reaction tube 101 were arranged so that the reaction tube 101 could be maintained at an arbitrary temperature.
　上述したような合成装置１００において、調製した固体触媒１３２ｇをとり、鉛直方向に設置した反応管１０１の中央部の石英焼結板１０６ａ上に導入することで触媒保持部１０６に触媒層を形成させた。反応管１０１内の温度が約８６０℃になるまで、触媒層を加熱しながら、反応管１０１底部から反応管１０１上部方向へ向けて線速制御部１０５の制御のもと窒素ガスを２１．６Ｌ／ｍｉｎで供給し、触媒層を通過するように流通させた。その後、窒素ガスを供給しながら、さらに線速制御部１０４の制御のもとメタンガスを１．０Ｌ／ｍｉｎで４６分間導入して触媒層を通過するように通気し、反応させた。この際のメタンを含むガスの線速（ｖ）は８．５５ｃｍ／ｓｅｃであった。メタンガスの導入を止め、窒素ガスを２１．６Ｌ／ｍｉｎ通気させながら、反応管１０１の内部を室温まで冷却した。加熱を停止させ室温まで放置し、室温になってから反応器から触媒とカーボンナノチューブを取り出した。 In the synthesizing apparatus 100 as described above, the prepared solid catalyst 132 g is taken and introduced onto the quartz sintered plate 106 a at the center of the reaction tube 101 installed in the vertical direction to form a catalyst layer on the catalyst holding unit 106. It was. While the catalyst layer is heated until the temperature in the reaction tube 101 reaches about 860 ° C., 21.6 L of nitrogen gas is controlled from the bottom of the reaction tube 101 toward the top of the reaction tube 101 under the control of the linear velocity control unit 105. / Min, and allowed to pass through the catalyst layer. Thereafter, while supplying nitrogen gas, under the control of the linear velocity control unit 104, methane gas was introduced at 1.0 L / min for 46 minutes, vented so as to pass through the catalyst layer, and reacted. The linear velocity (v) of the gas containing methane at this time was 8.55 cm / sec. The introduction of methane gas was stopped, and the inside of the reaction tube 101 was cooled to room temperature while supplying nitrogen gas at 21.6 L / min. The heating was stopped and the mixture was allowed to stand at room temperature, and after reaching room temperature, the catalyst and carbon nanotubes were taken out from the reactor.
（精製工程１：液相酸化処理＋アンモニア処理＋硝酸ドープ）
　得られたカーボンナノチューブが付着した触媒担体を約１３０ｇ用いて４．８Ｎの塩酸水溶液２０００ｍＬ中で１時間撹拌することで触媒金属である鉄とその担体であるＭｇＯを溶解した。得られた黒色懸濁液は濾過した後、濾取物を再度４．８Ｎの塩酸水溶液４００ｍＬに投入し脱ＭｇＯ処理をし、濾取した。本実施例では、この操作を２回繰り返して脱ＭｇＯ処理を行った。その後、イオン交換水で濾取物の懸濁液が中性となるまで水洗後、水を含んだウェット状態のままカーボンナノチューブを得た。 (Purification Step 1: Liquid Phase Oxidation Treatment + Ammonia Treatment + Nitric Acid Dope)
About 130 g of the obtained catalyst carrier with attached carbon nanotubes was stirred in 2000 mL of a 4.8N hydrochloric acid aqueous solution for 1 hour to dissolve the catalyst metal iron and the carrier MgO. The resulting black suspension was filtered, and the filtered material was again poured into 400 mL of a 4.8N hydrochloric acid aqueous solution, treated with MgO, and collected by filtration. In this example, this operation was repeated twice to remove MgO. Thereafter, the nanotubes were washed with ion exchange water until the suspension of the filtered material became neutral, and carbon nanotubes were obtained in a wet state containing water.
　得られたウェット状態のカーボンナノチューブの乾燥重量分に対して、約０．３倍の重量の濃硝酸（キシダ化学株式会社製　１級　Ａｓｓａｙ６０%）を添加した。その後、約１４０℃に加熱したオイルバスで２４時間攪拌しながら加熱還流した。加熱還流後、室温まで放冷し、カーボンナノチューブを含む硝酸溶液をイオン交換水で３倍に希釈して、オムニポアメンブレンフィルター（ミリポア社製、フィルタータイプ：１．０μｍＪＡ）を設置した内径９０ｍｍの濾過器を用いて吸引濾過した（液相酸化処理）。イオン交換水で濾取物の懸濁液が中性となるまで水洗後、水を含んだウェット状態のままカーボンナノチューブ（第１ウェットケーク）を得た。 Concentrated nitric acid (first grade Assay 60% manufactured by Kishida Chemical Co., Ltd.) about 0.3 times the weight was added to the dry weight of the obtained carbon nanotubes in the wet state. Thereafter, the mixture was heated to reflux with stirring in an oil bath heated to about 140 ° C. for 24 hours. After heating to reflux, the mixture was allowed to cool to room temperature, a nitric acid solution containing carbon nanotubes was diluted 3 times with ion-exchanged water, and an omnipore membrane filter (Millipore, filter type: 1.0 μm JA) was installed. Suction filtration was performed using a filter (liquid phase oxidation treatment). After washing with ion-exchanged water until the suspension of the filtered material became neutral, carbon nanotubes (first wet cake) were obtained in a wet state containing water.
　得られた第１ウェットケークを２８％アンモニア水溶液（キシダ化学株式会社製　特級）０．３Ｌに添加し、室温下で１時間撹拌した。その後、該溶液をオムニポアメンブレンフィルター（ミリポア社製、フィルタータイプ：１．０μｍＪＡ）を設置した内径９０ｍｍの濾過器を用いて吸引濾過した（アンモニア処理）。その後メンブレンフィルター上のウェットケークが中性付近になるまでイオン交換水で洗浄し、水を含んだウェット状態のままカーボンナノチューブ（第２ウェットケーク）を得た。 The obtained first wet cake was added to 0.3 L of a 28% aqueous ammonia solution (special grade, manufactured by Kishida Chemical Co., Ltd.) and stirred at room temperature for 1 hour. Thereafter, the solution was subjected to suction filtration (ammonia treatment) using a filter having an inner diameter of 90 mm provided with an omnipore membrane filter (manufactured by Millipore, filter type: 1.0 μm JA). Thereafter, the membrane was washed with ion-exchanged water until the wet cake on the membrane filter became near neutral, and carbon nanotubes (second wet cake) were obtained in a wet state containing water.
　得られた第２ウェットケークを６０％硝酸水溶液（キシダ化学株式会社製　１級　Ａｓｓａｙ６０%）０．３Ｌ中に添加した。室温で２４時間撹拌した後にミリポア社製オムニポアメンブレンフィルター（フィルタータイプ：１．０μｍＪＡ）を設置した内径９０ｍｍの濾過器を用いて吸引濾過した（硝酸ドープ）。その後メンブレンフィルター上のウェットケークが中性付近になるまでイオン交換水で洗浄した。この洗浄処理により得られた水を含んだウェット状態のカーボンナノチューブ（第３ウェットケーク）を保存した。 The obtained 2nd wet cake was added in 0.3 L of 60% nitric acid aqueous solution (Kishida Chemical Co., Ltd. grade 1 Assay 60%). After stirring at room temperature for 24 hours, suction filtration was performed using a filter having an inner diameter of 90 mm equipped with an Omnipore membrane filter (filter type: 1.0 μm JA) manufactured by Millipore (nitric acid dope). Thereafter, the membrane was washed with ion-exchanged water until the wet cake on the membrane filter became near neutral. Wet carbon nanotubes (third wet cake) containing water obtained by this washing treatment were stored.
　得られたウェット状態のカーボンナノチューブ（第３ウェットケーク）は適宜、１２０℃の乾燥機にて水分を蒸発させ、乾燥した形で用いた。 The obtained wet carbon nanotubes (third wet cake) were used in a dried form by appropriately evaporating water with a 120 ° C. drier.
（精製工程２：気相酸化処理）
　得られたカーボンナノチューブが付着した触媒担体３０ｇを磁性皿（φ１５０ｍｍ）に取り、マッフル炉（ヤマト科学株式会社製、ＦＰ４１）にて大気下、５００℃まで６０分かけて昇温し、さらに５００℃を維持した状態で６０分保持した後、自然放冷し、焼成したカーボンナノチューブ集合体を得た。 (Purification Step 2: Gas Phase Oxidation Treatment)
30 g of the obtained catalyst carrier with attached carbon nanotubes is placed in a magnetic dish (φ150 mm), heated in a muffle furnace (FP41, manufactured by Yamato Scientific Co., Ltd.) to 500 ° C. over 60 minutes, and further 500 ° C. Was maintained for 60 minutes, and then allowed to cool naturally to obtain a baked carbon nanotube aggregate.
　さらに、上記の焼成したカーボンナノチューブ集合体から触媒を除去するため、次のように精製処理を行った。まず、６Ｎの塩酸水溶液を焼成したカーボンナノチューブ集合体に添加し、８０℃のウォーターバス内で２時間攪拌した。孔径１μｍのフィルターを用いて濾過して得られた回収物を、６Ｎの塩酸水溶液に添加し、８０℃のウォーターバス内で６０分攪拌した。これを孔径１μｍのフィルターを用いて濾過し、数回水洗した後、濾過物を１２０℃のオーブンで一晩乾燥することでマグネシアおよび金属を除去でき、カーボンナノチューブを精製した。 Furthermore, in order to remove the catalyst from the above-mentioned calcined carbon nanotube aggregate, purification treatment was performed as follows. First, a 6N aqueous hydrochloric acid solution was added to the calcined carbon nanotube aggregate, and the mixture was stirred in a water bath at 80 ° C. for 2 hours. The recovered material obtained by filtration using a filter having a pore diameter of 1 μm was added to a 6N aqueous hydrochloric acid solution, and stirred in a water bath at 80 ° C. for 60 minutes. This was filtered using a filter having a pore diameter of 1 μm, washed with water several times, and then the filtrate was dried in an oven at 120 ° C. overnight to remove magnesia and metal, thereby purifying the carbon nanotubes.
　本実施例において、カーボンナノチューブの合成と各種物性評価は以下の方法で行った。 In this example, synthesis of carbon nanotubes and evaluation of various physical properties were performed by the following methods.
［カーボンナノチューブの分析］
　上述した参考例により製造した２層カーボンナノチューブについて各種分析を行った。 [Analysis of carbon nanotubes]
Various analyzes were performed on the double-walled carbon nanotubes produced according to the reference examples described above.
（精製工程１により得られた２層カーボンナノチューブの高分解能透過型電子顕微鏡分析）
　上記のようにして得た２層カーボンナノチューブを高分解能透過型電子顕微鏡で観察したところ、カーボンナノチューブはきれいなグラファイト層で構成されており、層数が２層のカーボンナノチューブが観察された。またカーボンナノチューブ１００本中、９１本を２層のカーボンナノチューブが占めていた。また任意に抽出した１００本のカーボンナノチューブについてカーボンナノチューブの外径を測定したときの算術平均値は１．７ｎｍであった。 (High-resolution transmission electron microscope analysis of double-walled carbon nanotubes obtained in purification step 1)
When the double-walled carbon nanotubes obtained as described above were observed with a high-resolution transmission electron microscope, the carbon nanotubes were composed of a clean graphite layer, and carbon nanotubes with two layers were observed. In addition, of the 100 carbon nanotubes, 91 carbon nanotubes were occupied by two-layer carbon nanotubes. Moreover, the arithmetic average value when the outer diameter of the carbon nanotube was measured for 100 arbitrarily extracted carbon nanotubes was 1.7 nm.
（精製工程１により得られた２層カーボンナノチューブのラマン分光分析）
　上記のようにして得た２層カーボンナノチューブに対し、ラマン分光測定を行った。ラマン分光計（ホリバ　ジョバンイボン社製　ＩＮＦ-３００）に粉末試料を設置し、６３３ｎｍのレーザー波長を用いて測定を行った。測定に際しては３箇所、別の場所にて分析を行い、相加平均をとった。その結果、Ｇ／Ｄ比は５２であり、グラファイト化度の高い高品質２層カーボンナノチューブであった。 (Raman spectroscopic analysis of double-walled carbon nanotubes obtained in purification step 1)
Raman spectroscopy measurement was performed on the double-walled carbon nanotubes obtained as described above. A powder sample was placed on a Raman spectrometer (INF-300 manufactured by Horiba Joban Yvon), and measurement was performed using a laser wavelength of 633 nm. In the measurement, the analysis was performed at three different locations, and an arithmetic average was taken. As a result, the G / D ratio was 52, and it was a high-quality double-walled carbon nanotube with a high degree of graphitization.
（精製工程１により得られた２層カーボンナノチューブのＸＰＳ分析）
　上記のようにして製造した２層カーボンナノチューブに対し、ＸＰＳ（X-ray　Photoelectron　Spectroscopy、Ｘ線光電子分光）測定を行った。ＸＰＳ測定は以下の条件で測定を行った。
　励起Ｘ線：Ｍｏｎｏｃｈｒｏｍａｔｉｃ　Ａｌ　Ｋ１，２線
　Ｘ線径：１０００μｍ
　光電子脱出角度：９０°（試料表面に対する検出器の傾き） (XPS analysis of double-walled carbon nanotubes obtained by purification step 1)
XPS (X-ray Photoelectron Spectroscopy, X-ray photoelectron spectroscopy) measurement was performed on the double-walled carbon nanotubes produced as described above. XPS measurement was performed under the following conditions.
Excitation X-ray: Monochromatic Al K 1, 2 wire X-ray diameter: 1000 μm
Photoelectron escape angle: 90 ° (inclination of detector with respect to sample surface)
　ＸＰＳ測定による表面組成（ａｔ％）解析の結果、Ｃ；９４．４％、Ｎ；０．２％、Ｏ；５．１％であった。したがって、カーボンナノチューブ中の炭素原子に対する酸素原子の割合は５．４％（ａｔ％）であった。 As a result of analyzing the surface composition (at%) by XPS measurement, C: 94.4%, N: 0.2%, O: 5.1%. Therefore, the ratio of oxygen atoms to carbon atoms in the carbon nanotube was 5.4% (at%).
［コンポジットの調製１］
　ナノチューブコンポジットは、エポキシ樹脂（Ａｒａｌｄｉｔｅ（登録商標）　ＬＹ　５０５２）と硬化剤（Ａｒａｌｄｉｔｅ（登録商標）　ＨＹ　５０５２）とからなる２液混合型エポキシを用いて調製した。超音波プローブ（Ｃｏｌｅ－Ｐａｒｍｅｒ社製　Ｕｌｔｒａｓｏｎｉｃ　Ｐｒｏｃｅｓｓｏｒ　ＣＰＸ　７５０、振幅　３５％、出力　７５０Ｗ)を用いてカーボンナノチューブを硬化剤に分散した。サンプルの過熱を避けるため、３０秒のプローブの使用後は次のプローブ処理までの間隔を３分間とし、この処理を６回繰り返して計５分の超音波を照射した。その後、樹脂：硬化剤が１００：３８の重量部割合となるよう、エポキシ樹脂を硬化剤に加えた。カーボンナノチューブ－エポキシコンポジットを、カーボンナノチューブを含まない同組成のエポキシ硬化物材の上にキャストし、室温で７日間静置して硬化させた。コンポジットのカーボンナノチューブ濃度は約０．０１ｗｔ％とした。 [Preparation of composite 1]
The nanotube composite was prepared using a two-component mixed epoxy composed of an epoxy resin (Araldite (registered trademark) LY 5052) and a curing agent (Araldite (registered trademark) HY 5052). The carbon nanotubes were dispersed in the curing agent using an ultrasonic probe (Ultrasonic Processor CPX 750 manufactured by Cole-Parmer, amplitude 35%, output 750 W). In order to avoid overheating of the sample, after using the probe for 30 seconds, the interval until the next probe treatment was 3 minutes, and this treatment was repeated 6 times to irradiate ultrasonic waves for a total of 5 minutes. Thereafter, an epoxy resin was added to the curing agent so that the resin: curing agent had a weight part ratio of 100: 38. The carbon nanotube-epoxy composite was cast on an epoxy cured material having the same composition and not containing carbon nanotubes, and allowed to stand at room temperature for 7 days to be cured. The carbon nanotube concentration of the composite was about 0.01 wt%.
［コンポジットの調製２］
　２ｍｇのカーボンナノチューブを超音波プローブ（Ｃｏｌｅ－Ｐａｒｍｅｒ社製　Ｕｌｔｒａｓｏｎｉｃ　Ｐｒｏｃｅｓｓｏｒ　ＣＰＸ　７５０、振幅　３５％、出力　７５０Ｗ)を用いて３０分間、超音波により５ｇの水に分散させた。カーボンナノチューブの懸濁液を１５ｇのＰＶＡ（Polyvinyl　Alcohol）水溶液に混合し、超音波バスを用いて１５時間超音波照射した。このとき、ＰＶＡの濃度は１０％であり、投入したカーボンナノチューブは０．１ｗｔ％（ポリマーに対して）である。ＰＶＡ／２層カーボンナノチューブ複合体フィルム（コンポジット）はＰＭＭＡ（Poly　Methyl　Methacrylate）上に超音波処理液をキャストし、１２時間乾燥することで作製した。 [Preparation of composite 2]
2 mg of carbon nanotubes were dispersed in 5 g of water by ultrasound for 30 minutes using an ultrasonic probe (Cole-Parmer Ultrasonic Processor CPX 750, amplitude 35%, output 750 W). The suspension of carbon nanotubes was mixed with 15 g of a PVA (Polyvinyl Alcohol) aqueous solution and subjected to ultrasonic irradiation for 15 hours using an ultrasonic bath. At this time, the concentration of PVA is 10%, and the input carbon nanotubes are 0.1 wt% (relative to the polymer). The PVA / 2-wall carbon nanotube composite film (composite) was prepared by casting an ultrasonic treatment solution on PMMA (Poly Methyl Methacrylate) and drying for 12 hours.
［ラマン分光分析法によるＧ’バンドシフト測定］
　ラマンスペクトルは、波長６３３ｎｍまたは５１４ｎｍを用いたＲｅｎｉｓｈａｗ　２０００（Ｒｅｎｉｓｈａｗ社製）で測定した。このとき、サンプルの加熱を避けるために、レーザーパワー密度は１４μＷ、スポットサイズは２μｍとした。Ｇ’バンドスペクトルについては、ＧｒａｍｓＡＩソフトウェアを使ってカーブフィッティングした。カーブフィッティングでは、Ｇ’バンドを、外層側カーボンナノチューブを示す２６３０ｃｍ－１（Ｇ’１）付近のピークと、内層側カーボンナノチューブを示す２５９０ｃｍ－１（Ｇ’２）付近のピークとにフィッティングした。カーボンナノチューブ－エポキシコンポジットに対し、それをサポートするエポキシ材ごと４点曲げにより機械的に歪みを与えた（図１参照）。コンポジットフィルムへの歪みはエポキシ材の表面歪みと同等に与えられ、歪みゲージで歪みを測定した。カーボンナノチューブからのラマンスペクトルを０～０．４％引張歪み範囲の異なる歪みレベルで採取した。 [G 'band shift measurement by Raman spectroscopy]
The Raman spectrum was measured with Renishaw 2000 (manufactured by Renishaw) using a wavelength of 633 nm or 514 nm. At this time, in order to avoid heating the sample, the laser power density was 14 μW and the spot size was 2 μm. For the G ′ band spectrum, curve fitting was performed using the GramsAI software. In curve fitting, the G ′ band was fitted to a peak near 2630 cm −1 (G ′ 1 ) indicating the outer layer side carbon nanotubes and a peak near 2590 cm −1 (G ′ 2 ) indicating the inner layer side carbon nanotubes. The carbon nanotube-epoxy composite was mechanically strained by 4-point bending with the epoxy material supporting it (see FIG. 1). The distortion to the composite film was given to be equivalent to the surface distortion of the epoxy material, and the distortion was measured with a strain gauge. Raman spectra from carbon nanotubes were collected at different strain levels in the 0-0.4% tensile strain range.
＜実施例１＞
　参考例（精製工程１）で記載した方法により得た２層カーボンナノチューブと、参考例（コンポジットの調製１）により得た２層カーボンナノチューブコンポジットとを用いた。
　図３は、本発明の実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。ラマン分光分析は、６３３ｎｍのレーザー波長を用いて行った。図３に示すように、付加歪みに対し、２つにピーク分割したＧ’バンドシフトであるＧ’１バンドシフトおよびＧ’２バンドシフトをプロットした。外層側カーボンナノチューブを示すＧ’１に応じた傾きは－１８．２ｃｍ－１／％、内層側カーボンナノチューブを示すＧ’２に応じた傾きは－１７．０ｃｍ－１／％であった。これにより、外層側カーボンナノチューブに由来する直線の傾きに対する内層側カーボンナノチューブに由来する直線の傾き（内層の傾き／外層の傾き）は、０．９３であった。このことは、コンポジットに歪みを与えたときの内層側カーボンナノチューブと外層側カーボンナノチューブとの応力伝達が大きく、ほとんど同等の応力を負担していることを示すばかりでなく、後述する比較例１に対比してマトリックスエポキシ樹脂と外層側カーボンナノチューブとの応力伝達が大きいことを示している。 <Example 1>
A double-walled carbon nanotube obtained by the method described in Reference Example (Purification Step 1) and a double-walled carbon nanotube composite obtained by Reference Example (Composite Preparation 1) were used.
FIG. 3 is a graph showing the relationship between strain and G ′ band shift in carbon nanotubes of a double-walled carbon nanotube-containing composite according to an example of the present invention. Raman spectroscopic analysis was performed using a laser wavelength of 633 nm. As shown in FIG. 3, G ′ 1 band shift and G ′ 2 band shift, which are G ′ band shifts divided into two peaks, are plotted against the added distortion. The inclination corresponding to G ′ 1 indicating the outer layer side carbon nanotube was −18.2 cm −1 /%, and the inclination corresponding to G ′ 2 indicating the inner layer side carbon nanotube was −17.0 cm −1 /%. Thereby, the inclination of the straight line derived from the inner layer side carbon nanotubes (inclination of the inner layer / inclination of the outer layer) with respect to the inclination of the straight line derived from the outer layer side carbon nanotubes was 0.93. This not only indicates that the stress transmission between the inner-layer side carbon nanotubes and the outer-layer side carbon nanotubes when strain is applied to the composite is large, and bears almost the same stress. In contrast, the stress transmission between the matrix epoxy resin and the outer-layer side carbon nanotubes is large.
＜実施例２＞
　参考例（精製工程１）で記載した方法により得た２層カーボンナノチューブと、参考例（コンポジットの調製２）により得た２層カーボンナノチューブコンポジットとを用いた。
　図４は、本実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。ラマン分光分析は６３３ｎｍのレーザー波長を用いて行った。図４に示すように、付加歪みに対し、２つにピーク分割したＧ’バンドシフトであるＧ’１バンドシフトおよびＧ’２バンドシフトをプロットした。内層側カーボンナノチューブを示すＧ’2に応じた傾きは－２３．０ｃｍ－１／％、外層側カーボンナノチューブを示すＧ’1に応じた傾きは－２９．０ｃｍ－１／％であった。これにより、外層側カーボンナノチューブに由来する直線の傾きに対する内層側カーボンナノチューブに由来する直線の傾き（内層の傾き／外層の傾き）は、０．７９であった。このことは、コンポジットに歪みを与えたときの内層側カーボンナノチューブと外層側カーボンナノチューブとの応力伝達が大きく、ほとんど同等の応力を負担していることを示すばかりでなく、後述する比較例１に対比してマトリックスエポキシ樹脂と外層側カーボンナノチューブとの応力伝達が大きいことを示している。 <Example 2>
A double-walled carbon nanotube obtained by the method described in Reference Example (Purification Step 1) and a double-walled carbon nanotube composite obtained by Reference Example (Composite Preparation 2) were used.
FIG. 4 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotubes of the double-walled carbon nanotube-containing composite according to this example. Raman spectroscopic analysis was performed using a laser wavelength of 633 nm. As shown in FIG. 4, G ′ 1 band shift and G ′ 2 band shift, which are G ′ band shifts divided into two peaks, are plotted against the added distortion. The slope corresponding to G ′ 2 indicating the inner layer side carbon nanotube was −23.0 cm −1 /%, and the slope corresponding to G ′ 1 indicating the outer layer side carbon nanotube was −29.0 cm −1 /%. Thereby, the inclination of the straight line derived from the inner-layer side carbon nanotubes (inclination of the inner layer / inclination of the outer layer) relative to the inclination of the straight line derived from the outer-layer side carbon nanotubes was 0.79. This not only indicates that the stress transmission between the inner-layer side carbon nanotubes and the outer-layer side carbon nanotubes when strain is applied to the composite is large and bears almost the same stress. In contrast, the stress transmission between the matrix epoxy resin and the outer-layer side carbon nanotubes is large.
＜実施例３＞
　ラマン分光分析を５１４ｎｍのレーザー波長を用いた以外は、実施例２と同様の操作を行った。
　図５は、本実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。図５に示すように、付加歪みに対し、２つにピーク分割したＧ’バンドシフトであるＧ’１バンドシフトおよびＧ’２バンドシフトをプロットした。内層側カーボンナノチューブを示すＧ’2に応じた傾きは－１９．０ｃｍ－１／％、外層側カーボンナノチューブを示すＧ’1に応じた傾きは－２６．０ｃｍ－１／％であった。これにより、外層側カーボンナノチューブに由来する直線の傾きに対する内層側カーボンナノチューブに由来する直線の傾き（内層の傾き／外層の傾き）は、０．７３であった。 <Example 3>
The same operation as in Example 2 was performed except that the laser wavelength of 514 nm was used for Raman spectroscopic analysis.
FIG. 5 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotubes of the double-walled carbon nanotube-containing composite according to this example. As shown in FIG. 5, G ′ 1 band shift and G ′ 2 band shift, which are G ′ band shifts divided into two peaks, are plotted against the added distortion. The slope corresponding to G ′ 2 indicating the inner layer side carbon nanotube was −19.0 cm −1 /%, and the slope corresponding to G ′ 1 indicating the outer layer side carbon nanotube was −26.0 cm −1 /%. Thereby, the inclination of the straight line derived from the inner layer side carbon nanotubes (inclination of the inner layer / inclination of the outer layer) with respect to the inclination of the straight line derived from the outer layer side carbon nanotubes was 0.73.
＜実施例４＞
　参考例（精製工程２）で記載した方法により得た２層カーボンナノチューブと、参考例（コンポジットの調製２）により得た２層カーボンナノチューブコンポジットとを用いた。また、ラマン分光分析は６３３ｎｍのレーザー波長を用いて行った。
　図６は、本実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。図６に示すように、付加歪みに対し、２つにピーク分割したＧ’バンドシフトであるＧ’１バンドシフトおよびＧ’２バンドシフトをプロットした。内層側カーボンナノチューブを示すＧ’2に応じた傾きは－２０．０ｃｍ－１／％、外層側カーボンナノチューブを示すＧ’1に応じた傾きは－２４．０ｃｍ－１／％であった。これにより、外層側カーボンナノチューブに由来する直線の傾きに対する内層側カーボンナノチューブに由来する直線の傾き（内層の傾き／外層の傾き）は、０．８３であった。このことは、コンポジットに歪みを与えたときの内層側カーボンナノチューブと外層側カーボンナノチューブとの応力伝達が大きく、ほとんど同等の応力を負担していることを示すばかりでなく、後述する比較例１に対比してマトリックスエポキシ樹脂と外層側カーボンナノチューブとの応力伝達が大きいことを示している。 <Example 4>
A double-walled carbon nanotube obtained by the method described in Reference Example (Purification Step 2) and a double-walled carbon nanotube composite obtained by Reference Example (Composite Preparation 2) were used. The Raman spectroscopic analysis was performed using a laser wavelength of 633 nm.
FIG. 6 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotubes of the double-walled carbon nanotube-containing composite according to this example. As shown in FIG. 6, G ′ 1 band shift and G ′ 2 band shift, which are G ′ band shifts divided into two peaks, are plotted against the added distortion. The slope corresponding to G ′ 2 indicating the inner-layer side carbon nanotube was −20.0 cm −1 /%, and the slope corresponding to G ′ 1 indicating the outer-layer side carbon nanotube was −24.0 cm −1 /%. Thereby, the inclination of the straight line derived from the inner-layer side carbon nanotubes (inclination of the inner layer / inclination of the outer layer) relative to the inclination of the straight line derived from the outer-layer side carbon nanotubes was 0.83. This not only indicates that the stress transmission between the inner-layer side carbon nanotubes and the outer-layer side carbon nanotubes when strain is applied to the composite is large and bears almost the same stress. In contrast, the stress transmission between the matrix epoxy resin and the outer-layer side carbon nanotubes is large.
＜実施例５＞
　ラマン分光分析を５１４ｎｍのレーザー波長を用いた以外は、実施例４と同様の操作を行った。
　図７は、本実施例にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。図７に示すように、付加歪みに対し、２つにピーク分割したＧ’バンドシフトであるＧ’１バンドシフトおよびＧ’２バンドシフトをプロットした。内層側カーボンナノチューブを示すＧ’2に応じた傾きは－１８．０ｃｍ－１／％、外層側カーボンナノチューブを示すＧ’1に応じた傾きは－２４．０ｃｍ－１／％であった。これにより、外層側カーボンナノチューブに由来する直線の傾きに対する内層側カーボンナノチューブに由来する直線の傾き（内層の傾き／外層の傾き）は、０．７５であった。 <Example 5>
The same operation as in Example 4 was performed, except that Raman spectroscopy was performed using a laser wavelength of 514 nm.
FIG. 7 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotubes of the double-walled carbon nanotube-containing composite according to this example. As shown in FIG. 7, G ′ 1 band shift and G ′ 2 band shift, which are G ′ band shifts divided into two peaks, were plotted against the added distortion. The slope corresponding to G ′ 2 indicating the inner layer side carbon nanotube was −18.0 cm −1 /%, and the slope corresponding to G ′ 1 indicating the outer layer side carbon nanotube was −24.0 cm −1 /%. Thereby, the inclination of the straight line derived from the inner layer side carbon nanotubes (inclination of the inner layer / inclination of the outer layer) relative to the inclination of the straight line derived from the outer layer side carbon nanotubes was 0.75.
＜比較例１＞
［ピーポッド由来２層カーボンナノチューブの調製］
　市販のアーク放電法単層カーボンナノチューブ（Ｎａｎｏｃａｒｂｌａｂ社製）を原料に２層カーボンナノチューブを製造した。まず、単層カーボンナノチューブを硝酸処理、空気中熱処理、アルゴン中での１０００℃熱処理を経て高純度化して供給した。単層カーボンナノチューブの断片化（短尺化）効果を最小限にするため、および後に続くポリマーへの分散工程を容易にするため、乾燥工程を、フリーズドライ法により行った。この処理の結果としての材料は、約７０％の単層カーボンナノチューブと約３０％の多層炭素シェルとを含む粉末であった（詳細は、S．Cui，et．al.,　Advanced　Materials,　21　(2009)　3591のSupporting　Informationを参照）。その単層カーボンナノチューブ（ＳＷＮＴｓ）を市販のフラーレン（ＡＬＦＡ　ＡＥＳＡＲ製、９８％Ｃ６０＋２％Ｃ７０、ｐｕｒｉｔｙ＞９８％）と混合した後、石英アンプルに導入した。水分散性を容易にするためにアンプル内を２００℃に維持しつつ、窒素置換、真空引きを繰り返し、最後に真空状態でシールした。そのアンプルは約５００℃に維持された熱処理炉に入れ、ピーポッド材料（Ｃ６０を含むＳＷＮＴｓ）となるように２４時間処理した。ピーポッド材料の収率は、７５％程度であった。その他の成分は単層カーボンナノチューブのままであった。石英アンプルを開封し、熱処理炉に入れて１３００℃まで真空中で処理した。この処理でフラーレンを合一させて単層カーボンナノチューブとし、単層カーボンナノチューブ中に単層カーボンナノチューブを、すなわち２層カーボンナノチューブを合成した。単層カーボンナノチューブに導入されなかった余剰のフラーレンは熱処理昇温過程における昇華によって除去した。ピーポッド材料中のフラーレン間のスペースにより、合一させた単層カーボンナノチューブは、外層側カーボンナノチューブの全長に渡って完全な一本のチューブである内層側カーボンナノチューブに生成することは出来ず、空の部分を含む結果となった。Ｘ線回折法によって、内層側カーボンナノチューブと外層側カーボンナノチューブのナノチューブ長さ比は０．６以下と計算された。ただし、フラーレンのまま存在しているものや２０ｎｍ以下の短い内層側カーボンナノチューブはほとんど見つからなかった。 <Comparative Example 1>
[Preparation of peapod-derived double-walled carbon nanotubes]
Double-walled carbon nanotubes were produced from commercially available arc discharge single-walled carbon nanotubes (Nanocarblab). First, single-walled carbon nanotubes were supplied after being purified through nitric acid treatment, heat treatment in air, and heat treatment at 1000 ° C. in argon. In order to minimize the fragmentation (shortening) effect of the single-walled carbon nanotube and to facilitate the subsequent dispersion step in the polymer, the drying step was performed by freeze drying. The material resulting from this treatment was a powder containing about 70% single-walled carbon nanotubes and about 30% multi-walled carbon shell (for details see S.Cui, et.al., Advanced Materials, 21 ( 2009) See 3591 Supporting Information). The single-walled carbon nanotubes (SWNTs) were mixed with a commercially available fullerene (manufactured by ALFA AESAR, 98% C 60 + 2% C 70 , purity> 98%) and then introduced into a quartz ampoule. In order to facilitate water dispersibility, nitrogen replacement and evacuation were repeated while maintaining the inside of the ampoule at 200 ° C., and finally, sealing was performed in a vacuum state. Ampoule was placed in a heat treatment furnace maintained at about 500 ° C., for 24 hours so that the (SWNTs containing C 60) peapods material. The yield of peapod material was about 75%. The other components remained as single-walled carbon nanotubes. The quartz ampoule was opened, placed in a heat treatment furnace and processed in vacuum up to 1300 ° C. By this treatment, fullerenes were combined to form single-walled carbon nanotubes, and single-walled carbon nanotubes, that is, double-walled carbon nanotubes were synthesized in the single-walled carbon nanotubes. Excess fullerene that was not introduced into the single-walled carbon nanotubes was removed by sublimation in the heat treatment temperature rising process. Due to the space between fullerenes in the peapod material, united single-walled carbon nanotubes cannot be formed into inner-wall-side carbon nanotubes, which are a complete tube, over the entire length of outer-wall-side carbon nanotubes. The result including the part of. By the X-ray diffraction method, the nanotube length ratio between the inner layer side carbon nanotubes and the outer layer side carbon nanotubes was calculated to be 0.6 or less. However, few fullerenes or short inner-wall side carbon nanotubes of 20 nm or less were found.
　図８は、本実施例（比較例１）にかかる２層カーボンナノチューブ含有複合体のカーボンナノチューブにおける歪みとＧ’バンドシフトとの関係を示すグラフである。図８に示すように、付加歪みに対し、２つにピーク分割したＧ’バンドシフトであるＧ’１バンドシフトおよびＧ’２バンドシフトをプロットした。外層側カーボンナノチューブを示すＧ’１に応じた傾きは－１１ｃｍ－１／％、内層側カーボンナノチューブを示すＧ’２に応じた傾きは－０．７ｃｍ－１／％であった。これにより、外層側カーボンナノチューブに由来する直線の傾きに対する内層側カーボンナノチューブに由来する直線の傾き（内層の傾き／外層の傾き）は、０．０６であった。このことは、内層側カーボンナノチューブと外層側カーボンナノチューブとの間で応力伝搬されていないことを示している。 FIG. 8 is a graph showing the relationship between strain and G ′ band shift in the carbon nanotube of the double-walled carbon nanotube-containing composite according to this example (Comparative Example 1). As shown in FIG. 8, G ′ 1 band shift and G ′ 2 band shift, which are G ′ band shifts divided into two peaks, are plotted against the added distortion. The inclination according to G ′ 1 indicating the outer layer side carbon nanotube was −11 cm −1 /%, and the inclination according to G ′ 2 indicating the inner layer side carbon nanotube was −0.7 cm −1 /%. Thereby, the inclination of the straight line derived from the inner layer side carbon nanotubes (inclination of the inner layer / inclination of the outer layer) relative to the inclination of the straight line derived from the outer layer side carbon nanotubes was 0.06. This indicates that stress is not propagated between the inner-layer side carbon nanotubes and the outer-layer side carbon nanotubes.
　本発明の２層カーボンナノチューブ含有複合体は、２層カーボンナノチューブと樹脂との親和性が高く、かつ機械強度が高い２層カーボンナノチューブ含有複合体を取得することに好適に採用できる。 The double-walled carbon nanotube-containing composite of the present invention can be suitably used to obtain a double-walled carbon nanotube-containing composite having high affinity between the double-walled carbon nanotube and the resin and high mechanical strength.
　１　複合体
　１０　基材
　１００　合成装置
　１０１　反応管
　１０２　電気炉
　１０３　導入管
　１０３ａ　側管
　１０４，１０５　線速制御部
　１０４ａ　炭素源供給部
　１０５ａ　キャリアガス供給部
　１０６　触媒保持部
　１０６ａ　石英焼結板
　１０７　回収部
　１０７ａ　ガス排出管
　１０８　温度計 DESCRIPTION OF SYMBOLS 1 Composite 10 Base material 100 Synthesizer 101 Reaction tube 102 Electric furnace 103 Introduction tube 103a Side tube 104,105 Linear speed control unit 104a Carbon source supply unit 105a Carrier gas supply unit 106 Catalyst holding unit 106a Quartz sintered plate 107 Recovery unit 107a Gas exhaust pipe 108 Thermometer

Claims (9)

  1. 　内層側カーボンナノチューブおよび外層側カーボンナノチューブからなる２層カーボンナノチューブと、樹脂とを含む２層カーボンナノチューブ含有複合体であって、
    　荷重を加えた状態でラマン分光分析した場合に得られる当該２層カーボンナノチューブ含有複合体の歪みとＧ’バンドシフトとの関係を示すグラフにおいて、前記外層側カーボンナノチューブに由来する直線の傾きに対する前記内層側カーボンナノチューブに由来する直線の傾きの比の値が、０．５以上１．５以下である２層カーボンナノチューブ含有複合体。     A double-walled carbon nanotube-containing composite comprising a double-walled carbon nanotube composed of an inner-layer side carbon nanotube and an outer-layer side carbon nanotube, and a resin,
    In the graph showing the relationship between the strain of the double-walled carbon nanotube-containing composite and the G ′ band shift obtained when the Raman spectroscopic analysis is performed in a state where a load is applied, the slope with respect to the slope of the straight line derived from the outer-layer-side carbon nanotubes A double-walled carbon nanotube-containing composite in which the value of the ratio of the slope of the straight line derived from the inner-layer side carbon nanotube is 0.5 or more and 1.5 or less.
  2. 　前記２層カーボンナノチューブは、酸素を含む官能基で修飾されている請求項１に記載の２層カーボンナノチューブ含有複合体。 The double-walled carbon nanotube-containing composite according to claim 1, wherein the double-walled carbon nanotube is modified with a functional group containing oxygen.
  3. 　前記官能基は、水酸基またはカルボシキル基である請求項２に記載の２層カーボンナノチューブ含有複合体。 The double-walled carbon nanotube-containing composite according to claim 2, wherein the functional group is a hydroxyl group or a carboxyl group.
  4. 　前記２層カーボンナノチューブ中の炭素原子に対する酸素原子の割合が、０．１ａｔ％以上２０ａｔ％以下である請求項２または３に記載の２層カーボンナノチューブ含有複合体。 The double-walled carbon nanotube-containing composite according to claim 2 or 3, wherein a ratio of oxygen atoms to carbon atoms in the double-walled carbon nanotube is 0.1 at% or more and 20 at% or less.
  5. 　前記２層カーボンナノチューブを波長６３３ｎｍでラマン分光分析した場合のＤバンドの高さに対するＧバンドの高さの比の値が、２０以上である請求項１～４のいずれか一つに記載の２層カーボンナノチューブ含有複合体。 The ratio of the height of the G band to the height of the D band when the double-walled carbon nanotube is subjected to Raman spectroscopic analysis at a wavelength of 633 nm is 20 or more. Single-wall carbon nanotube-containing composite.
  6. 　前記樹脂は、熱硬化性樹脂である請求項１～５のいずれか一つに記載の２層カーボンナノチューブ含有複合体。 The double-walled carbon nanotube-containing composite according to any one of claims 1 to 5, wherein the resin is a thermosetting resin.
  7. 　前記樹脂は、エポキシ樹脂である請求項１～６のいずれか一つに記載の２層カーボンナノチューブ含有複合体。 The double-walled carbon nanotube-containing composite according to any one of claims 1 to 6, wherein the resin is an epoxy resin.
  8. 　前記２層カーボンナノチューブは、前記樹脂に対して、０．００１重量％以上１０重量％以下で含まれる請求項１～７のいずれか一つに記載の２層カーボンナノチューブ含有複合体。 The double-walled carbon nanotube-containing composite according to any one of claims 1 to 7, wherein the double-walled carbon nanotube is contained in an amount of 0.001 wt% to 10 wt% with respect to the resin.
  9. 　前記外層側カーボンナノチューブに由来する直線の傾きの絶対値が、１０ｃｍ－１／％以上５０ｃｍ－１／％以下である請求項１～８のいずれか一つに記載の２層カーボンナノチューブ含有複合体。 The double-walled carbon nanotube-containing composite according to any one of claims 1 to 8, wherein an absolute value of a slope of a straight line derived from the outer-layer-side carbon nanotube is 10 cm -1 /% or more and 50 cm -1 /% or less. .
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