JP2002273741A - Carbon nano-tube composite molded object and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbon nano-tube composite molded object capable of developing excellent anisotropic function not obtained heretofore with respect to properties such as electrical properties, thermal properties mechanical properties or the like, and a method for manufacturing the same. SOLUTION: The carbon nano-tube composite molded object 5 is molded in such a state that carbon nano-tubes 6 are arranged in a matrix in a definite direction to be compounded with the matrix. As the matrix, at least one kind of an organic polymer selected from a thermoplastic resin, a curable resin, rubber and a thermoplastic elastomer is preferable. The composite molded object 5 is manufactured by injecting a composition, wherein the carbon nano- tubes 6 are contained in the matrix, in the molding recessed part of a mold and applying a magnetic field to the composition in a difinite direction by a magnet to arrange the carbon nano-tubes 6 in the definite direction to solidify the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing carbon nanotubes in which carbon nanotubes are arranged in a certain direction in a matrix, exhibiting anisotropic functions with respect to properties such as electrical properties, thermal properties, and mechanical properties. The present invention relates to a carbon nanotube composite molded article that can be used as a part, a heat conductive material, a high-strength material, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, carbon nanotubes and a method for producing carbon nanotubes have been disclosed in Japanese Patent Application Laid-Open Nos. 5-125619 and 7-216660. According to these publications, utilizing the specific functions of carbon nanotubes, electron-emitting devices, hydrogen storage, thin-film batteries, probes, micromachines, semiconductor integrated circuits, conductive materials, heat conductive materials, high-strength high-elastic materials, etc. Many interesting application developments are being actively considered.

[0003]

However, a carbon nanotube composite molded article obtained by solidifying a composition obtained by blending a conventional carbon nanotube with a matrix of resin, rubber, metal, ceramics, etc. Mainly those that were dispersed in random directions. Therefore, the mechanical properties obtained,
It was an isotropic material having functions such as electrical conductivity and electron emission characteristics randomly, that is, having the same function in any direction.

On the other hand, a composition containing carbon nanotubes in a matrix is formed in a flow field or a shear field,
It is possible to arrange the carbon nanotubes in the flow direction by a method of stretching the composition or the like. However, in the method of arranging the carbon nanotubes in the flow direction, it is impossible to arrange the carbon nanotubes in the thickness direction of the plate-like molded body, and it is not always possible to control the arrangement of the carbon nanotubes in any direction. Was.

Further, JP-A-11-194134 and JP-A-10-265208 disclose carbon nanotubes in a gas phase in a certain direction from catalyst molecules such as iron, cobalt and nickel arranged on a substrate. A growing manufacturing method has been proposed. However, when carbon nanotubes are arranged in a certain direction on a flat substrate using this method, only a composite molded body in which carbon nanotubes are arranged in a direction perpendicular to a plane can be obtained. Therefore,
It has been difficult to produce a carbon nanotube composite molded article of any shape.

The present invention has been made by paying attention to the problems existing in the above prior art. An object of the present invention is to provide a carbon nanotube composite molded article capable of exhibiting an excellent anisotropic function, which has not been obtained conventionally, with respect to properties such as electric properties, thermal properties, and mechanical properties, and a method for producing the same. Is to provide.

[0007]

That is, the carbon nanotube composite molded article according to the first aspect of the present invention is characterized in that carbon nanotubes are arranged in a matrix in a fixed direction and are composited. It is assumed that.

[0008] In the carbon nanotube composite molded article according to the second aspect of the present invention, in the invention according to the first aspect, the matrix is at least one kind selected from a thermoplastic resin, a curable resin, a rubber, and a thermoplastic elastomer. It is characterized by being an organic polymer.

According to a third aspect of the present invention, there is provided a method for producing a carbon nanotube composite molded article, wherein a magnetic field is applied to a composition containing a carbon nanotube in a matrix, and the composition is solidified in a state where the carbon nanotubes are arranged in a predetermined direction. It is characterized by being molded.

According to a fourth aspect of the present invention, there is provided the method for producing a carbon nanotube composite molded article according to the third aspect, wherein the matrix comprises a thermoplastic resin, a curable resin,
It is characterized by being at least one organic polymer selected from rubber and thermoplastic elastomer.

Therefore, a carbon nanotube composite molded article in which carbon nanotubes are arranged in an arbitrary direction has a function or a function that is exhibited depending on the direction, such as the electrical properties, thermal properties, and mechanical properties of the carbon nanotube. A composite molded article having anisotropy with different degrees is obtained.

For example, regarding the electrical properties, as a conductive material, the added amount of carbon nanotubes is smaller and higher than in the case where the electrical conductivity is high in a specific direction and not arranged in a certain direction. Electric conductivity can be exhibited. In addition, the electron emission characteristics of carbon nanotubes are considered to be the most efficient when electrons are emitted from the ends of the nanotubes. It is possible to arrange the parts.

With regard to thermal properties, for example, when carbon nanotubes are arranged in the thickness direction of a plate-like molded body, a difference occurs between the thermal conductivity in a direction parallel to the arrangement and the thermal conductivity in a direction perpendicular to the arrangement. In other words, the carbon nanotube itself has a higher thermal conductivity in the axial direction than in the direction perpendicular to the axis. Material. In this case, it is preferable that the carbon nanotubes be graphitized to further improve the thermal conductivity.

Regarding the mechanical properties, for example, when the carbon nanotubes are arranged in one direction perpendicular to the thickness direction of the plate-like molded body, anisotropy of the elastic modulus is generated, and the tensile strength and the resistance to resistance are higher than the other directions. Flexural strength and the like are improved.

In addition, it can exhibit anisotropy in magnetic properties, linear expansion coefficients, dielectric properties, radio wave absorption properties, etc., and can be used in various applications such as vibration damping materials and radio wave absorbers. it can.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. The carbon nanotube composite molded body is
The carbon nanotubes are arranged in a predetermined direction in a matrix and formed in a composite state. The carbon nanotube composite molded article is used after being molded into a plate, a tube, a lump, or any other shape.

The type and production method of the carbon nanotubes used in the present invention are not particularly limited. The carbon nanotubes are made of carbon and have a tube shape with a diameter on the order of nanometers. For example, Japanese Unexamined Patent Publication
Carbon nanotubes obtained by the production methods disclosed in JP-A-157016, JP-A-6-280116, JP-A-10-203810, JP-A-11-11917 and the like can be used. It has become common to use the arc discharge method to synthesize carbon nanotubes, but in addition, laser evaporation, thermal decomposition,
In recent years, methods utilizing plasma discharge have been studied, and carbon nanotubes obtained by those methods can also be used.

The carbon nanotube has a structure in which hexagonal meshes composed of carbon atoms are connected in a tube shape.
A single-walled hexagonal mesh tube is called a single-walled nanotube (hereinafter, abbreviated as SWNT), while a multi-walled hexagonal tube is called a multi-walled nanotube (MWNT).
). The structure of the carbon nanotube to be obtained is determined to some extent by the synthesis method, conditions, and the like.

In the product, amorphous carbon nanoparticles, fullerenes, metal nanoparticles, and the like are mixed as by-products together with the carbon nanotubes. These by-products may be contained. Fullerenes and the like can be extracted because they are soluble in organic solvents such as toluene, hydrogen disulfide, benzene, and chlorobenzene. In addition, since the interlayer between the carbon nanotubes is narrower than the interlayer between the carbon nanoparticles and the graphite pieces, utilizing this fact, only the nanoparticles and the graphite pieces are selectively formed as interlayer compounds,
It can be removed by sintering at lower temperatures. As a result, the consumption of nanotubes due to combustion can be suppressed by the lower processing temperature, and the recovery rate increases.

Although it depends on the method of production, the carbon nanotube is a material having a high aspect ratio, and the produced one often has a complicatedly entangled structure. These may be dispersed by ultrasonic dispersion or the like, but preferably, the carbon nanotubes may be pulverized under predetermined conditions so that the length of the carbon nanotubes is shorter than that at the time of generation. The method of the pulverization treatment is not limited, but a dry pulverization method such as shearing or grinding, or a method using a ball mill or a homogenizer containing water or an organic solvent containing a surfactant or the like is employed.

The carbon nanotube used in the present invention is not limited to either SWNT or MWNT. Furthermore, carbon nanotubes containing metals or other inorganic or organic substances, carbon nanotubes filled with carbon or other substances, carbon nanotubes in a coiled (spiral) or fibril shape, and other so-called nanofibers Can also be used. Also,
The diameter and length of the carbon nanotube are not limited, but the diameter of the carbon nanotube is preferably in the range of 1 to 20 nm, and the tube length is preferably in the range of 50 nm to 100 μm from the viewpoint of ease of production and function development.

Next, the matrix in which the carbon nanotubes are blended is a material serving as a base material in which the carbon nanotubes are blended. Examples of this matrix include resins, rubbers, thermoplastic elastomers, adhesives, paints, inks, metals, alloys, ceramics, cements, gels,
Paper, fiber, woven fabric, non-woven fabric and the like can be used. The matrix can be selected according to the required properties of the target composite molded article, such as hardness, mechanical strength, heat resistance, electrical properties, durability, and reliability. Among them, at least one organic polymer selected from a thermoplastic resin, a curable resin, a rubber, and a thermoplastic elastomer, which is easily moldable, is preferable.

Specific examples of the thermoplastic resin include polyethylene, polypropylene, ethylene-α-olefin copolymers such as ethylene-propylene copolymer, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, and ethylene acetate. -Vinyl acetate copolymer, polyvinyl alcohol, polyvinyl acetal, fluorine-based polymers such as polyvinylidene fluoride and polytetrafluoroethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polystyrene,
Polyacrylonitrile, styrene-acrylonitrile copolymer, ABS resin, polyphenylene ether and modified PPE resin, aliphatic and aromatic polyamides, polyimide, polyamideimide, polymethacrylic acid esters such as polymethacrylic acid and its methyl ester, polyacrylic Examples thereof include acids, polycarbonate, polyphenylene sulfide, polysulfone, polyether sulfone, polyether nitrile, polyether ketone, polyketone, liquid crystal polymer, silicone resin, and thermoplastic resins such as ionomer.

Examples of the curable resin include epoxy resin, phenol resin, acrylic resin, urethane resin, polyimide resin, unsaturated polyester resin, diallyl phthalate resin, dicyclopentadiene resin, benzocyclobutene resin and the like. The curing mode of the curable resin is not limited to the thermosetting property, and a resin obtained by a curing method according to an ordinary method such as photo-curing property and moisture-curing property can be used.

As the rubber, natural rubber or synthetic rubber can be used. As synthetic rubber, butadiene rubber, isoprene rubber, styrene butadiene copolymer rubber,
Nitrile rubber, hydrogenated nitrile rubber, chloroprene rubber,
Examples include ethylene-propylene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, butyl rubber and halogenated butyl rubber, fluorine rubber, urethane rubber, and silicone rubber.

Examples of the thermoplastic elastomer include a styrene-butadiene or styrene-isoprene block copolymer and a hydrogenated polymer thereof, a styrene-based thermoplastic elastomer, an olefin-based thermoplastic elastomer, a vinyl chloride-based thermoplastic elastomer, and a polyester-based thermoplastic elastomer. , A polyurethane-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, and the like. In consideration of recyclability, it is preferable to use the above-mentioned thermoplastic resin or thermoplastic elastomer.

Among them, at least one selected from silicone rubber, epoxy resin, polyimide resin, bismaleimide resin, benzocyclobutene resin, fluorine resin and polyphenylene ether resin, particularly at least one selected from silicone rubber, epoxy resin and polyimide resin It is preferable to use one type from the viewpoint of reliability.

Further, a polymer alloy comprising a plurality of organic polymers selected from the above may be blended, a known plasticizer, a filler, a curing agent, organic fibers such as carbon fiber, glass fiber, and aramid fiber, and a stabilizer. An additive such as a coloring material may be blended.

For the purpose of facilitating the incorporation of carbon nanotubes to be added into the matrix and the ease of alignment when a magnetic field is applied, it is preferable to reduce the viscosity of the composition by adding an organic solvent or water. is there. further,
A dispersion stabilizer such as a surfactant may be used for the purpose of improving the dispersion state.

The amount of carbon nanotubes to be mixed in the matrix is as follows:
The range of 0.01 to 100 parts by weight is preferred. If the amount is less than 0.01 part by weight, the anisotropic function cannot be sufficiently exhibited, and if it exceeds 100 parts by weight, the dispersibility of the carbon nanotubes in the matrix is undesirably reduced. Actually, the amount of carbon nanotubes varies depending on the type of matrix material used, other additives, etc., and the strength of the magnetic field used. The practical range is 0.1 to 20 parts by weight.

Further, in order to improve the wettability and adhesion between the carbon nanotube and the matrix material, the surface of the carbon nanotube is subjected to a degreasing treatment or a washing treatment in advance, an ultraviolet irradiation treatment, a corona discharge treatment, a plasma treatment, a flame treatment, or the like. It is preferable to perform an activation treatment such as a treatment or an ion implantation treatment. In addition, by treating with a silane-based, titanium-based, or aluminum-based coupling agent after these surface treatments, a larger amount of carbon nanotubes can be easily dispersed and mixed. Functionalization can be achieved.

The method for dispersing the carbon nanotubes in the matrix is not particularly limited. For example, in the case of a liquid polymer, a predetermined amount of carbon nanotubes may be added and mixed with an ordinary mixer or blender. Further, a treatment using ultrasonic waves or vibration may be performed for the purpose of improving the mixed and dispersed state. It is preferable to perform a defoaming operation by vacuum or pressure for the purpose of removing mixed air. In the case of a solid polymer such as a pellet or powder, a predetermined amount of carbon nanotubes can be added and kneaded and dispersed using a conventional kneading machine such as an extruder, kneader, or roll.

The strength of the magnetic field applied to arrange the carbon nanotubes in a certain direction is preferably in the range of 0.05 to 30 Tesla as the magnetic flux density. When the magnetic flux density is less than 0.05 Tesla, the carbon nanotubes cannot be arranged in a certain direction sufficiently. When the magnetic flux density exceeds 30 Tesla, the strength of the magnetic field is excessive and the effect of the arrangement is not further improved. Actually, it can be set experimentally according to the type and amount of matrix and carbon nanotubes used, the shape of the carbon nanotube composite molded product to be obtained, and the required performance of the final product. As a magnetic flux density that can be arranged in a uniform manner, a range of 5 to 20 Tesla is practical.

As a means for generating a magnetic field applied from the outside, a permanent magnet, an electromagnet, a coil, or the like can be used. In the present invention, since the diamagnetic carbon nanotubes can be arranged in a direction parallel to the magnetic field lines, the direction of the magnetic field may be such that the N pole and the S pole of the magnet are arranged according to the desired arrangement direction. . In addition, the magnets may be arranged so that the N poles face each other, the magnets may be arranged only on one side, or the magnetic force lines may be arranged in a curved line. That is, the direction of the lines of magnetic force may be adjusted to apply the magnetic field so that the anisotropy of the desired function is exhibited.

The obtained mixed composition is formed into a desired shape such as a plate, a tube, a block, or the like by a press molding method, an extrusion molding method, a transfer molding method, a calendar molding method, or the like to produce a composite molded body. Can be. Further, it can be processed into a thin film by a process such as painting or printing. In the carbon nanotube composite molded article thus obtained, the carbon nanotubes are arranged in an arbitrary fixed direction, and this fact can be confirmed by an enlarged photograph by an electron microscope.

The effects exerted by the above-described embodiment will be summarized below. In the carbon nanotube composite molded article described in the embodiment, the carbon nanotubes are arranged in an arbitrary fixed direction. For this reason, properties such as electrical properties, thermal properties, and mechanical properties are different between the direction in which the carbon nanotubes extend and the other directions, and an excellent anisotropic function, which has not been obtained conventionally, can be exhibited. Moreover, since the carbon nanotube is a very minute material, the minute composite molded body can exhibit an anisotropic function.

In such a carbon nanotube composite molded article, by applying a magnetic field to the composition containing carbon nanotubes, the carbon nanotubes in the matrix can be efficiently arranged in any given direction.

In addition, the carbon nanotube composite molded article has magnetic properties, electromagnetic properties, linear expansion coefficients,
Anisotropy can be exhibited in dielectric properties and the like. Therefore, it can be used for various applications such as a pressure sensor, a pressure-sensitive switch, a magnetic shield material, a magnetic recording material, and a magnetic filter.

[0039]

EXAMPLES Hereinafter, the above-described embodiment will be described more specifically with reference to examples. In each of the examples, the carbon nanotubes produced based on the following synthesis examples were used. In each of the examples and comparative examples, a carbon nanotube composite molded article molded in a plate shape will be described, but the present invention is not limited to this.

Hereinafter, a thermal decomposition method using a catalyst will be described as an example of a method for synthesizing carbon nanotubes used in each example. This method is almost the same as the carbon fiber vapor deposition method.

That is, first, ethylene and propane are introduced into the thermostat together with hydrogen as a raw material gas. In this case, the raw material gas may be methane, ethane,
Raw materials containing saturated hydrocarbons such as propane, butane, hexane, and cyclohexanone, unsaturated hydrocarbons such as ethylene, propylene, benzene, and toluene, and oxygen such as acetone, methanol, and carbon monoxide may be used.

Next, the above-mentioned raw material gas introduced into the constant temperature bath is heated or cooled to control the vapor pressure, and further introduced into the pyrolysis furnace by a hydrogen gas flow, and ethylene or propane as the raw material gas is heated. Decomposition produces carbon nanotubes. (Example 1) A manufacturing apparatus and a manufacturing method for manufacturing a plate-like carbon nanotube composite molded article of the present example will be described with reference to FIGS.

As shown in FIG. 2, a pair of dies 1a, 1b
Are formed facing each other, and a molding concave portion 2 corresponding to a target plate-like carbon nanotube composite molded body is formed in the facing surface of one mold 1a. Both molds 1a, 1
b is formed of aluminum, and the inner surface of the molded concave portion 2 is coated with a fluororesin. Then, a composition 3 obtained by adding 1 part by weight of carbon nanotubes to 100 parts by weight of a thermosetting unsaturated polyester resin (trade name: Epolak G-157MB, manufactured by Nippon Shokubai Co., Ltd.) and stirring was added to a mold 1a. , 1b.

Next, as shown in FIG.
b was clamped with a constant pressure to seal the molding recess 2. Thereafter, as shown in FIG. 4, a pair of magnets 4a, 4b are disposed at both ends of the molds 1a, 1b, and the N poles of the magnets 4a, 4b and the S
The pole was opposed. That is, a magnetic field of 10 Tesla was applied in one direction parallel to the inner bottom surface of the molding concave portion 2 and cured at room temperature for 30 minutes. Thereafter, the molds 1a and 1b were opened, and the carbon nanotube composite molded body 5 was taken out from the molding concave portion 2.

As shown in FIG. 1, the carbon nanotubes 6 in the obtained plate-shaped composite molded body 5 are formed on the upper and lower surfaces (FIG. 1).
(Upper surface or lower surface) of the substrate. (Embodiment 2) 1 in the direction perpendicular to the inner bottom surface of the molding recess 2
A carbon nanotube composite molded body 5 was obtained in the same manner as in Example 1 except that a magnetic field of 0 Tesla was applied. The carbon nanotubes 6 in the obtained plate-shaped composite molded body 5 are:
As shown in FIG. 5, the composite molded bodies 5 were arranged vertically with the upper and lower surfaces. (Example 3) Thermosetting epoxy resin (EPO-TEC)
A composition obtained by adding 1 part by weight of carbon nanotubes to 100 parts by weight of Epotek 310 (trade name, manufactured by Company H) and stirring the mixture was filled in the molding concave portion 2 of the mold shown in FIG. Thereafter, the same operation as in Example 1 was performed to obtain a carbon nanotube composite molded body 5. (Example 4) Thermosetting epoxy resin (EPO-TEC)
A composition obtained by adding 2 parts by weight of carbon nanotubes to 100 parts by weight of Epotek 310 (manufactured by Company H) and stirring the mixture was filled in the molding recess 2 of the mold 1a shown in FIG. Thereafter, the same operation as in Example 1 was performed to obtain a carbon nanotube composite molded body. (Example 5) A composition in which 1 part by weight of carbon nanotubes was kneaded with a screw extruder per 100 parts by weight of a thermoplastic polycarbonate resin (trade name: Iupilon S-2000 manufactured by Mitsubishi Engineering-Plastics Corporation) was used. Methylene chloride was added and stirred until dissolved into a homogeneous liquid. The obtained solution was filled in the molding recess 2 of the mold 1a shown in FIG. Thereafter, while applying a magnetic field of 10 Tesla in one direction parallel to the inner bottom surface of the molding recess 2,
The mixture was solidified by heating at 0 ° C. for 1 hour to obtain a carbon nanotube composite molded body 5. (Example 6) A carbon nanotube composite molded body 5 was obtained in the same manner as in Example 5 except that a magnetic field of 10 Tesla was applied in a direction perpendicular to the inner bottom surface of the molding concave portion 2 of the mold 1a. (Comparative Example 1) Thermosetting unsaturated polyester resin [trade name: Epolac G-157MB manufactured by Nippon Shokubai Co., Ltd.] 10
Composition 1 obtained by adding 1 part by weight of carbon nanotubes to 0 part by weight and stirring was filled in the molding recess 2 of the mold 1a shown in FIG. After that, without applying a magnetic field,
The mixture was allowed to stand for 0 minutes and cured to obtain a carbon nanotube composite molded article. The carbon nanotubes in the obtained composite molded body were dispersed in random directions. (Comparative Example 2) Thermosetting epoxy resin (EPO-TEC)
A composition obtained by adding 1 part by weight of carbon nanotubes to 100 parts by weight of Epotek 310 (manufactured by Company H) and stirring the mixture was filled in the molding recess 2 of the mold 1a shown in FIG. Thereafter, without applying a magnetic field, the mixture was allowed to stand at room temperature for 30 minutes to be cured to obtain a carbon nanotube composite molded body. (Comparative Example 3) Thermosetting epoxy resin (EPO-TEC)
A composition obtained by adding 2 parts by weight of carbon nanotubes to 100 parts by weight of Epotek 310 (manufactured by Company H) and stirring the mixture was filled in the molding recess 2 of the mold 1a shown in FIG. Thereafter, without applying a magnetic field, the mixture was left standing at room temperature for 30 minutes to be cured, thereby producing a carbon nanotube composite molded body. (Comparative Example 4) 100 parts by weight of a thermoplastic polycarbonate resin (trade name: Iupilon S-2000 manufactured by Mitsubishi Engineering-Plastics Corporation) and 100 parts by weight of pellets obtained by kneading 1 part by weight of carbon nanotubes with a screw extruder Then, 70 parts by weight of methylene chloride was added, and the mixture was stirred until the pellets were completely dissolved. The obtained solution was filled in the molding recess 2 of the mold 1a shown in FIG.
Thereafter, the mixture was heated and solidified at 120 ° C. for 1 hour without applying a magnetic field to obtain a carbon nanotube composite molded body.

The carbon nanotube composite molded articles obtained in Examples 1, 2, 5 and 6 and Comparative Examples 1 and 4 were subjected to a dynamic viscoelasticity measuring apparatus [Ryovibron DDV-III manufactured by Orientec Co., Ltd.] ], The storage elastic modulus E, the loss elastic modulus E, and the loss tangent tan at a frequency of 11 Hz.
δ was measured. The results are shown in Table 1.

[0047]

[Table 1] In addition, the magnetic susceptibility カ ー ボ ン at 0 to 5 T of the carbon nanotube composite molded products obtained in Examples 3 and 4 and Comparative Examples 2 and 3 was measured with a SQUID magnetization measuring device (manufactured by Quantum Design, MPMS-7). Table 2 shows the results. The measurement directions in Tables 2 to 4 below have the following meanings.

Parallel: Measured in a direction parallel to the direction of the carbon nanotube. Vertical: Measured in the direction perpendicular to the direction of the carbon nanotube. None: A sample in which the carbon nanotubes were not arranged in a certain direction but were randomly dispersed was measured.

[0049]

[Table 2] Further, the electrical resistance value of the carbon nanotube composite molded body obtained in Example 3 and Comparative Example 2 was measured, and the results were shown in Table 3.
It was shown to. The electric resistance is a value calculated by measuring a voltage between two terminals when a current of 1 mA DC is applied at a distance between terminals of 1 mm.

[0050]

[Table 3] Further, the carbon nanotube composite molded articles obtained in Examples 1 and 2 and Comparative Example 1 were subjected to a thermomechanical analysis and measurement apparatus (TMA-40, manufactured by METTLER COMPANY, TA-3000) to obtain a coefficient of linear expansion at a temperature of 30 to 200 ° C. Was measured. Table 4 shows the results.

[0051]

[Table 4] In particular, in Example 3 in Table 2, magnetic anisotropy is recognized from the change in the magnetic susceptibility χ. Further, in Example 3 of Table 3, anisotropy in electric resistance is recognized from a change in electric resistance value. Further, for Example 1 in Table 4, the anisotropy of linear expansion is recognized from the change in the coefficient of linear expansion. In addition, as shown in Table 1, in Example 1, regarding the storage elastic modulus E and the loss elastic modulus E, the direction parallel to the upper and lower surfaces of the molded body was larger than the direction perpendicular to the molded body, and the elastic modulus was excellent. Was.

The present invention can be configured by modifying the above embodiment as follows. The direction of the magnetic field applied to the composition 3 containing carbon nanotubes in the matrix may be set obliquely to the inner bottom surface of the molding recess 2 of the mold 1a.

A coating of a ferromagnetic material or the like may be formed on the surface of the carbon nanotube so that the carbon nanotubes are arranged effectively. With this configuration, the anisotropy can be more effectively exerted.

Carbon fibers such as graphitized carbon fibers can be blended with the carbon nanotubes in the matrix. With this configuration, it is possible to exhibit anisotropy in thermal conductivity and electrical insulation.

Using a metal, ceramics or other inorganic substance or a precursor thereof as a matrix, applying a magnetic field in a molten state or a solvent-dispersed state, then cooling and solidifying or drying and firing to produce a composite molded article be able to. For example, an aluminum alloy composition containing carbon nanotubes is accommodated in a container having a predetermined shape and melted, and in this state, a magnetic field is applied to arrange the carbon nanotubes in a certain direction. Can be manufactured. Furthermore, a composition such as a phenolic resin or an epoxy resin containing the carbon nanotubes is contained in a container having a predetermined shape and melted.A magnetic field is applied in this state to arrange the carbon nanotubes in a certain direction. The matrix is carbonized or graphitized by firing to produce a carbon nanotube-carbon composite molded article. With such a configuration, anisotropy such as hardness, mechanical strength, heat resistance, electrical characteristics, and durability of the composite molded body can be exhibited.

Further, the technical idea grasped from the embodiment will be described below. The carbon nanotube has a diameter of 1 to 20 nm and a length of 50 nm to 100 μm.
2. The carbon nanotube composite molded article according to item 1. With this configuration, the carbon nanotubes can be easily produced, and the anisotropic function of the carbon nanotube composite molded article can be effectively exhibited.

The compounding amount of the carbon nanotube is 0.1 to 20 parts by weight based on the matrix.
Or the carbon nanotube composite molded product according to claim 2. With this configuration, the carbon nanotubes can be arranged by the magnetic field, and the anisotropic function can be effectively exhibited.

The strength of the magnetic field is 5 to 2 as a magnetic flux density.
The method for producing a carbon nanotube composite molded article according to claim 3, wherein the carbon nanotube composite is 0 tesla. According to this method, the carbon nanotubes can be effectively arranged.

[0059]

As described above, according to the present invention, the following effects can be obtained.

According to the carbon nanotube composite molded article of the first aspect of the present invention, an excellent anisotropic function, which has not been obtained conventionally, is exhibited in properties such as electric properties, thermal properties and mechanical properties. can do.

According to the carbon nanotube composite molded article of the second aspect of the present invention, in addition to the effects of the first aspect of the present invention, the moldability for obtaining a desired shape is excellent. According to the method for producing a carbon nanotube composite molded article according to the third aspect of the present invention, it is possible to efficiently obtain a carbon nanotube composite molded article exhibiting the effects of the first aspect.

According to the method for producing a carbon nanotube composite molded article of the invention described in claim 4, in addition to the effect of the invention described in claim 3, the molding processability for obtaining a desired shape is excellent.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a carbon nanotube composite molded body of Example 1.

FIG. 2 is a sectional view showing a state in which a molding die is opened.

FIG. 3 is a cross-sectional view showing a state in which a composition is injected into a molding recess of a mold and the mold is clamped.

FIG. 4 is a cross-sectional view showing a state in which a pair of magnets are arranged at both ends of the mold and a magnetic field is applied to the composition in the molding concave portion, following the state of FIG. 3;

FIG. 5 is a schematic explanatory view showing a carbon nanotube composite molded body of Example 2.

[Explanation of symbols]

5: Carbon nanotube composite molded article, 6: Carbon nanotube.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 101/00 C08L 101/00 // B29K 21:00 B29K 21:00 101: 10 101: 10 (72) Inventor Toru Kimura 5-10-5 Tabata, Kita-ku, Tokyo Polymerec R & D Center (72) Inventor Morio Yumura 1-1, Higashi, Tsukuba, Ibaraki Pref. In-house (72) Inventor Tetsu Oshima 1-1 East Higashi Tsukuba, Ibaraki Pref. Ministry of Economy, Trade and Industry, National Institute of Advanced Industrial Science and Technology (72) Inventor Hiroki Ago 1-1 East East Tsukuba, Ibaraki Pref. (72) Inventor Kunio Uchida 1-1, Higashi 1-1, Tsukuba, Ibaraki Pref., Ministry of Economy, Trade and Industry (72) Inventor, Yozo Kakudate 1-1, Higashi, Tsukuba, Ibaraki, Japan Ministry of Economy, Trade and Industry, National Institute of Advanced Industrial Science and Technology (72) Inventor, Hiroyuki Yokoi, East 1, Tsukuba, Ibaraki -1 Ministry of Economy, Trade and Industry, National Institute of Advanced Industrial Science and Technology (AIST) Material Engineering and Industrial Technology Research Institute F-term (reference) DA036 FD116

Claims (4)

[Claims] 1. A carbon nanotube composite molded article characterized in that carbon nanotubes are arranged in a matrix in a matrix and formed in a composite state. 2. The carbon nanotube composite molded article according to claim 1, wherein the matrix is at least one organic polymer selected from a thermoplastic resin, a curable resin, a rubber, and a thermoplastic elastomer. 3. A method for producing a carbon nanotube composite molded body, comprising applying a magnetic field to a composition containing carbon nanotubes in a matrix, solidifying and molding the carbon nanotubes in a state where the carbon nanotubes are arranged in a certain direction. Method. 4. The carbon nanotube composite molded article according to claim 3, wherein the matrix is at least one organic polymer selected from a thermoplastic resin, a curable resin, a rubber, and a thermoplastic elastomer. Production method.