JP6576074B2 - Method for producing carbon nanotube composite material - Google Patents

Description

  The present invention relates to a carbon nanotube composite material and a method for producing the carbon nanotube composite material.

  Carbon nanotubes are known to have excellent mechanical strength, thermal conductivity and electrical conductivity. It has been studied that such carbon nanotubes are combined with other materials and used for various industrial products.

  For example, a heat conductive sheet that is a composite of a polymer matrix and a carbon nanotube array in which a plurality of carbon nanotubes are arranged has been proposed (see, for example, Patent Document 1).

JP 2009-51725 A

  However, the heat conductive sheet described in Patent Document 1 is prepared by filling a carbon nanotube array with a liquid polymer precursor and then polymerizing the polymer precursor.

  For this reason, the orientation of the plurality of carbon nanotubes may be disturbed due to shrinkage or the like when the polymer precursor is polymerized, and it is possible to accurately secure the orientation of the plurality of carbon nanotubes in the heat conductive sheet. Have difficulty.

  As a result, such a heat conductive sheet has a limit in improving heat conductivity and electric conductivity with high accuracy in the thickness direction (the orientation direction of carbon nanotubes).

  Accordingly, an object of the present invention is to provide a carbon nanotube composite material capable of combining a matrix and a carbon nanotube yarn, and capable of accurately improving thermal conductivity and electrical conductivity in a predetermined direction, and a carbon nanotube composite It is in providing the manufacturing method of material.

  The carbon nanotube composite material of the present invention comprises a matrix and carbon nanotube yarns having carbon nanotubes and composited with the matrix, and the matrix has a tensile elastic modulus E at 25 ° C. of 0.01 GPa or more and 5 GPa. The carbon nanotube yarn penetrates the matrix in a predetermined direction.

  According to such a configuration, since the tensile elastic modulus E at 25 ° C. of the matrix is 5 GPa or less, the carbon nanotube yarn can penetrate the matrix, and the tensile elastic modulus E at 25 ° C. of the matrix is 0.01 GPa or more. Therefore, the matrix can be in close contact with the carbon nanotube yarns penetrating the matrix by its elastic force. Therefore, while the matrix and the carbon nanotube yarn can be reliably combined, the matrix can reliably hold the carbon nanotube yarn, and the carbon nanotube yarn can be prevented from falling off the matrix.

  And since the carbon nanotube thread | yarn has penetrated the matrix in the predetermined direction, the thermal conductivity and electrical conductivity of the carbon nanotube composite material can be improved with high precision in the predetermined direction.

  That is, according to the carbon nanotube composite material of the present invention, the matrix and the carbon nanotube yarn can be surely combined, and the characteristics of the matrix can be ensured while improving the thermal conductivity and electrical conductivity in a predetermined direction. It can be achieved with high accuracy.

  Further, it is preferable that the carbon nanotube yarn is a bundle of a plurality of carbon nanotube single yarns in which a plurality of carbon nanotubes are continuously connected in the extending direction of the carbon nanotube.

  According to such a configuration, in the carbon nanotube single yarn, since the plurality of carbon nanotubes are continuously connected in the extending direction thereof, the plurality of carbon nanotubes extend in the carbon nanotube single yarn. Oriented along the direction.

  Therefore, in the carbon nanotube yarn in which a plurality of carbon nanotube single yarns are bundled, the orientation of the carbon nanotubes can be reliably ensured.

  Further, the carbon nanotube yarn is preferably a twisted yarn in which a plurality of the carbon nanotube single yarns are twisted together.

  According to such a configuration, since the carbon nanotube yarn is a twisted yarn in which a plurality of carbon nanotube single yarns are twisted together, the strength of the carbon nanotube yarn can be reliably ensured, and the carbon nanotube yarn can be reliably used as a matrix. Can be penetrated.

  It is preferable that a plurality of the carbon nanotube yarns penetrate the matrix in the same direction.

  According to such a configuration, a plurality of carbon nanotube yarns penetrates the matrix in the same direction (predetermined direction), so that the thermal conductivity and electrical conductivity in the predetermined direction of the carbon nanotube composite material can be reliably improved. be able to.

  The carbon nanotube yarn is preferably cut so that a plurality of portions penetrating the matrix are separated from each other.

  However, when the carbon nanotube yarn is a continuous yarn that penetrates the matrix in the same direction and is continuous, the outer carbon nanotube exposed on the surface of the carbon nanotube yarn among the plurality of carbon nanotube single yarns of the carbon nanotube yarn. While the single yarn is in contact with the object, it is difficult to ensure contact between the inner (center) carbon nanotube single yarn that is not exposed on the surface of the carbon nanotube yarn and the object.

  Therefore, the carbon nanotube single yarn inside the carbon nanotube yarn may not be effectively used for heat conduction and / or electric conduction.

  On the other hand, according to the above configuration, the carbon nanotube yarn is cut so that a plurality of portions penetrating the matrix are separated from each other. Therefore, all of the plurality of carbon nanotube single yarns are cut on the cut surface of the carbon nanotube yarn. Exposed.

  Therefore, all of the plurality of carbon nanotube single yarns can be easily brought into contact with the object. As a result, a plurality of carbon nanotube single yarns of the carbon nanotube yarn can be efficiently used for heat conduction and / or electrical conduction, and thus further increase in thermal conductivity and electrical conductivity in a predetermined direction of the carbon nanotube composite material. Improvements can be made.

  The carbon nanotube is preferably a multi-walled carbon nanotube.

  According to such a configuration, the carbon nanotube is a multi-walled carbon nanotube in which a plurality of graphene sheets are laminated in the radial direction, and the carbon nanotube thread is cut. All layers (multiple graphene sheets) are exposed. Therefore, all the layers of the multi-walled carbon nanotube can be used for heat conduction and / or electric conduction, and as a result, the heat conductivity and electric conductivity in a predetermined direction of the carbon nanotube composite material can be further improved. .

  The method for producing a carbon nanotube composite of the present invention comprises a step of preparing a carbon nanotube yarn having carbon nanotubes, a step of preparing a matrix having a tensile elastic modulus E at 25 ° C. of 0.01 GPa to 5 GPa, and the carbon And a step of compositing the carbon nanotube yarn into the matrix, wherein the carbon nanotube yarn is penetrated through the matrix in a predetermined direction.

  According to such a method, since the tensile elastic modulus E at 25 ° C. of the matrix is 5 GPa or less, the carbon nanotube yarn can be penetrated through the matrix in a predetermined direction, and the tensile elastic modulus E at 25 ° C. of the matrix is 0. Since it is 0.01 GPa or more, the matrix can reliably hold the carbon nanotube yarn. Therefore, the carbon nanotube yarn can be accurately oriented in a desired direction. As a result, excellent thermal conductivity and electrical conductivity can be imparted to the matrix in the desired direction.

  Therefore, it is possible to produce a carbon nanotube composite material having excellent thermal conductivity and electrical conductivity in a desired direction while being a simple method.

  In addition, the step of preparing the carbon nanotube yarn includes a step of preparing a carbon nanotube aggregate including a plurality of carbon nanotubes arranged on a substrate and oriented perpendicularly to the substrate, and from the carbon nanotube aggregate. Preferably, the method includes a step of drawing out a plurality of carbon nanotube single yarns in which the plurality of carbon nanotubes are continuously connected in the extending direction of the carbon nanotubes, and a step of bundling the plurality of carbon nanotube single yarns.

  According to such a method, since the carbon nanotube single yarn is pulled out from the carbon nanotube aggregate including the plurality of carbon nanotubes oriented perpendicular to the substrate, the plurality of carbon nanotubes are in the carbon nanotube single yarn. The carbon nanotubes are oriented along the direction in which the single yarns extend.

  Therefore, in the carbon nanotube yarn in which a plurality of carbon nanotube single yarns are bundled, the orientation of the carbon nanotubes can be reliably ensured.

  According to the carbon nanotube composite material of the present invention, the matrix and the carbon nanotube yarn can be combined, and the thermal conductivity and electrical conductivity in a predetermined direction can be improved with high accuracy.

  Moreover, although the manufacturing method of the carbon nanotube composite material of this invention is a simple method, it can manufacture the carbon nanotube composite material which has the outstanding heat conductivity and electrical conductivity in the desired direction.

FIG. 1A is a perspective view of a first embodiment of the carbon nanotube composite of the present invention. FIG. 1B is a cross-sectional view of the carbon nanotube composite shown in FIG. 1A. FIG. 2A is an explanatory diagram for explaining a process of preparing a carbon nanotube single yarn according to the carbon nanotube yarn shown in FIG. 1A, and shows a step of forming a catalyst layer on a substrate. FIG. 2B shows a process of heating the substrate to agglomerate the catalyst layer into a plurality of granules following FIG. 2A. FIG. 2C shows a process of growing a plurality of carbon nanotubes by supplying a raw material gas to a plurality of granular bodies following FIG. 2B. FIG. 2D shows a process of drawing a plurality of carbon nanotubes and preparing a carbon nanotube single yarn following FIG. 2C. FIG. 3A is a perspective view of a spinning device for producing a carbon nanotube yarn by bundling a plurality of carbon nanotube single yarns shown in FIG. 2D. FIG. 3B is a schematic view of the carbon nanotube shown in FIG. 3A. FIG. 4A is an explanatory diagram for explaining a step of compositing the carbon nanotube yarn shown in FIG. 3A into a matrix, and shows a step of preparing the carbon nanotube yarn and the matrix. FIG. 4B shows a process of sewing the carbon nanotube thread to the matrix following FIG. 4A. FIG. 4C shows a process of cutting the carbon nanotube yarn following FIG. 4B. FIG. 4D shows a schematic configuration diagram of carbon nanotubes in the carbon nanotube yarn shown in FIG. 4B. FIG. 4E shows a schematic configuration diagram of carbon nanotubes in the carbon nanotube yarn shown in FIG. 4C. FIG. 5A is an explanatory diagram for explaining the sewing of the carbon nanotube yarn shown in FIG. 3A to the matrix by the sewing machine, and shows a step of sewing the carbon nanotube yarn to the matrix. FIG. 5B shows a process of cutting the carbon nanotube yarn following FIG. 5A. FIG. 6A is a cross-sectional view of a second embodiment of the carbon nanotube composite of the present invention. FIG. 6B is a cross-sectional view of a third embodiment of the carbon nanotube composite of the present invention. FIG. 6C is a cross-sectional view of the fourth embodiment of the carbon nanotube composite of the present invention. FIG. 7 is a perspective view of a fifth embodiment of the carbon nanotube composite of the present invention. FIG. 8 is a schematic configuration diagram of another embodiment of the spinning device (a configuration including an immersion part). FIG. 9A is a schematic configuration diagram of an electronic element unit including the carbon nanotube composite material shown in FIG. 1 as a heat conductive sheet. FIG. 9B is a schematic configuration diagram of a wearable biosensor including the carbon nanotube composite shown in FIG. 1 as an electrically conductive sheet. FIG. 10 is a graph showing the thermal conductivity with respect to the density of the carbon nanotube yarns in Examples 1 and 2 and Comparative Example 1.

1. Configuration of Carbon Nanotube Composite As shown in FIG. 1A and FIG. 1B, the carbon nanotube composite 1 includes a matrix 2 and a carbon nanotube thread 3, and preferably includes a matrix 2 and a carbon nanotube thread 3. The matrix 2 and the carbon nanotube yarn 3 are composited.

  The matrix 2 is a base material of the carbon nanotube composite material 1 and has elasticity. Specifically, the tensile elastic modulus E at 25 ° C. of the matrix 2 is 0.01 GPa or more, preferably 0.08 GPa or more, more preferably 0.5 GPa or more and 5 GPa or less, preferably 3 GPa or less. As a method for measuring the tensile elastic modulus E of the matrix 2, a known method is appropriately selected according to the material of the matrix 2. For example, when the matrix 2 is made of a thermoplastic resin (described later), it conforms to JIS K 7161 (2014), and when the matrix 2 is composed of a thermosetting resin (described later), it is determined according to JIS K 6251 (2010). Calculated from tensile stress and strain (tensile stress / strain). Moreover, the tensile elasticity modulus E of the matrix 2 can also be confirmed by various well-known literatures.

  When the tensile elastic modulus E at 25 ° C. of the matrix 2 is not more than the above upper limit, the carbon nanotube yarns 3 can be surely penetrated through the matrix 2 and the handling property of the matrix 2 can be improved. Moreover, the elasticity of the matrix 2 can be ensured reliably and the matrix 2 can hold | maintain the carbon nanotube thread | yarn 3 reliably that the tensile elasticity modulus E in 25 degreeC of the matrix 2 is more than the said minimum.

  The material of the matrix 2 is not particularly limited as long as the tensile elastic modulus E of the matrix 2 is in the above range, and examples thereof include a resin material. Examples of the resin material include a thermoplastic resin and a thermosetting resin.

  Examples of the thermoplastic resin include polyester (for example, polyethylene terephthalate), polyolefin (for example, polyethylene, polypropylene, etc.), polyamide, polystyrene, polyvinyl chloride, polyvinyl alcohol, polyvinylidene chloride, polyacrylonitrile, polyurethane, fluorine-based polymer, A thermoplastic elastomer etc. are mentioned.

  Among such thermoplastic resins, a fluorine polymer and a thermoplastic elastomer are preferable.

  Examples of the fluorine-based polymer include polytetrafluoroethylene (PTFE), polyvinyl fluoride, and polyvinylidene fluoride. Preferably, polytetrafluoroethylene (PTFE) is used.

  Examples of the thermoplastic elastomer include olefin elastomers (for example, ethylene-propylene rubber, ethylene-propylene-diene rubber, etc.), styrene elastomers, vinyl chloride elastomers, and preferably olefin elastomers. More preferably, an ethylene-propylene rubber is mentioned.

  The thermosetting resin is a cured body (thermosetting resin after curing), and examples thereof include an epoxy resin, a polyimide resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin, and a thermosetting elastomer. It is done.

  Among such thermosetting resins, a thermosetting elastomer is preferable. Examples of the thermosetting elastomer include vulcanized rubber, silicone rubber, acrylic rubber and the like, and preferably silicone rubber.

  The shape of the matrix 2 is not particularly limited and can be appropriately changed according to the application. Specifically, examples of the shape of the matrix 2 include a sheet shape, a columnar shape (for example, a columnar shape, a prismatic shape, etc.), a spherical shape, and the like, and preferably a sheet shape.

  In the first embodiment, a case where the matrix 2 has a sheet shape will be described. That is, the matrix 2 has a flat plate shape, specifically, has a predetermined thickness, extends in a surface direction (vertical direction and horizontal direction) orthogonal to the thickness direction, and has a flat front surface 2A and a flat back surface 2B. have. Further, the matrix 2 may have a circular shape in a plan view as indicated by a virtual line in FIG. 1A, and a polygonal shape (for example, a quadrangle, a hexagon, etc.) as indicated by a solid line in FIG. 1A. ).

  The thickness of the matrix 2 is not particularly limited, and is, for example, 1 μm or more, preferably 300 μm or more, more preferably 10 mm or more, for example, 500 mm or less, preferably 100 mm or less, and more preferably 50 mm or less.

In addition, the area of the front surface 2A (back surface 2B) of the matrix 2 is, for example, 1 cm ² or more, preferably 10 cm ² or more, for example, 300 cm ² or less, preferably 100 cm ² or less.

  The mass ratio of the matrix 2 is, for example, 91.04% by mass or more, preferably 96.21% by mass or more, for example, 99.99% by mass or less, with respect to 100% by mass of the carbon nanotube composite material 1. Preferably, it is 99.80 mass% or less.

  As shown in FIG. 3A, the carbon nanotube yarn 3 has a plurality of carbon nanotubes 5 and is formed in a yarn shape (linear shape). For example, the carbon nanotube yarn 3 includes (consists of) a plurality of carbon nanotube single yarns 4, and the plurality of carbon nanotube single yarns 4 are bundled.

  The carbon nanotube single yarn 4 has a plurality of carbon nanotubes 5 as shown in FIG. 2D, and the plurality of carbon nanotubes 5 are continuously linear in the extending direction of the carbon nanotube single yarn 4. It is connected. That is, the plurality of carbon nanotubes 5 are oriented along the extending direction of the carbon nanotube single yarn 4.

  Each of the plurality of carbon nanotubes 5 may be either a single-walled carbon nanotube or a multi-walled carbon nanotube, and is preferably a multi-walled carbon nanotube as shown in FIG. 3B. These carbon nanotubes 5 can be used alone or in combination of two or more.

  In FIG. 3B, FIG. 4D and FIG. 4E, for convenience, the carbon nanotubes 5 are described as being three-layer multi-wall carbon nanotubes, but the number of multi-wall carbon nanotubes 5 is not limited to this. 2 layers or more, preferably 3 layers or more, more preferably 4 layers or more, for example, 50 layers or less, preferably 40 layers or less.

  The average outer diameter of the carbon nanotube 5 is, for example, 1 nm or more, preferably 5 nm or more, for example, 100 nm or less, preferably 50 nm or less, and more preferably 20 nm or less.

  The average length (average axial dimension) of the carbon nanotube 5 is, for example, 1 μm or more, preferably 100 μm or more, more preferably 200 μm or more, for example, 1000 μm or less, preferably 500 μm or less, more preferably 400 μm or less. It is. The number of layers, the average outer diameter, and the average length of the carbon nanotube 5 are measured by a known method such as Raman spectroscopic analysis or electron microscope observation.

  The outer diameter of the carbon nanotube single yarn 4 is, for example, 30 nm or more, preferably 60 nm or more, for example, 100 nm or less, preferably 80 nm or less.

  The carbon nanotube yarn 3 may be a non-twisted yarn in which a plurality of carbon nanotube single yarns 4 are not twisted together, but is preferably a twisted yarn in which a plurality of carbon nanotube single yarns 4 are twisted together.

  The outer diameter of the carbon nanotube yarn 3 is, for example, 5 μm or more, preferably 40 μm or more, for example, 80 μm or less, preferably 60 μm or less, and more preferably 30 μm or less.

Further, the bulk density of the carbon nanotube yarn 3 is, for example, 0.6 g / cm ³ or more, preferably more than 0.6 g / cm ³ , more preferably 0.8 g / cm ³ or more, for example, 2. 0 g / cm ³ or less.

  Further, the thermal conductivity of the carbon nanotube yarn 3 is 2 W / (m · K) or more, preferably 5 W / (m · K) or more, for example, 1000 W / (m) in the extending direction of the carbon nanotube yarn 3. · K) or less, preferably 500 W / (m · K) or less. The thermal conductivity is measured by a known thermal conductivity measuring device (for example, manufactured by Mentor Graphics Japan).

  Further, the electric conductivity of the carbon nanotube yarn 3 is, for example, 1000 S / m or more, preferably 2500 S / m or more, for example, 500,000 S / m or less, preferably 250,000 S / m or less in the extending direction of the carbon nanotube yarn 3. It is. The electrical conductivity is measured by a known electrical conductivity measuring device (for example, manufactured by Yokogawa Electric Corporation).

  That is, the carbon nanotube yarn 3 has thermal conductivity and electrical conductivity in the extending direction of the carbon nanotube yarn 3.

  The carbon nanotube thread 3 penetrates the matrix 2 in the thickness direction and is held by the matrix 2 as shown in FIG. 1B. In the first embodiment, a plurality of carbon nanotube yarns 3 are held in the matrix 2, and each of the plurality of carbon nanotube yarns 3 penetrates the matrix 2 along the thickness direction. That is, a plurality of carbon nanotube yarns 3 penetrates the matrix 2 in the thickness direction, and the plurality of carbon nanotube yarns 3 extend so as to be substantially parallel independently of each other.

  Specifically, the carbon nanotube yarn 3 penetrates the matrix 2 as a carbon nanotube yarn bundle 6 in which two or more carbon nanotube yarns 3 are bundled.

  The carbon nanotube yarn bundle 6 has 2 or more, preferably 4 or more, for example, 50 or less, preferably 30 or less carbon nanotube yarns 3. 1A, 1B, and 4A to 4C show a case where the carbon nanotube yarn bundle 6 has two carbon nanotube yarns 3. FIG.

  Further, as shown in FIG. 1A and FIG. 1B, a plurality of carbon nanotube yarn bundles 6 are linearly arranged at intervals in the longitudinal direction to constitute a yarn bundle row 7. A plurality of yarn bundle rows 7 are arranged in parallel in the lateral direction at intervals.

  In the yarn bundle row 7, the interval between the carbon nanotube yarn bundles 6 adjacent to each other is, for example, 0.5 mm or more, preferably 1 mm or more, for example, 50 mm or less, preferably 10 mm or less.

  Moreover, the space | interval between the mutually adjacent thread bundle row | line | columns 7 among several yarn bundle row | line | columns 7 is 0.5 mm or more, for example, Preferably, it is 1 mm or more, for example, 50 mm or less, Preferably, it is 10 mm or less.

The density of such a plurality of carbon nanotube yarn bundles 6 is, for example, 1 bundle / cm ² or more, preferably 2 bundles / cm ² or more, for example, 360 bundles / cm ² per unit area of the surface 2A of the matrix ^2. Hereinafter, it is preferably 80 bundles / cm ² or less.

  In each carbon nanotube yarn bundle 6, both ends of the carbon nanotube yarn 3 protrude from the matrix 2. That is, the length L of the carbon nanotube yarn 3 is larger than the thickness of the matrix 2 and is, for example, 1.05 times or more, preferably 1.1 times or more, for example, 1.3 times the thickness of the matrix 2. 2 times or less, preferably 1.2 times or less.

  Specifically, the carbon nanotube yarn 3 has an embedded portion 3A, a first end portion 3B, and a second end portion 3C.

  The embedded portion 3 </ b> A is a substantially central portion of the carbon nanotube yarn 3. The embedded portion 3 </ b> A is embedded in the matrix 2 and is in close contact with the matrix 2. The length L1 of the embedded portion 3A is, for example, 76.9% or more, preferably 83.3% or more, for example, 95.2% or less, preferably 90%, with respect to the length L of the carbon nanotube yarn 3. .9% or less.

  The first end 3 </ b> B is one end in the thickness direction of the carbon nanotube yarn 3 and protrudes from the surface 2 </ b> A of the matrix 2. The length L2 of the first end 3B is, for example, 2.4% or more, preferably 4.5% or more, for example, 11.5% or less, preferably with respect to the length L of the carbon nanotube yarn 3. , 8.3% or less.

  The second end 3 </ b> C is the other end in the thickness direction of the carbon nanotube yarn 3 and protrudes from the back surface 2 </ b> B of the matrix 2. The range of the length L2 of the second end 3C is the same as the range of the length L2 of the first end 3B.

The density of the plurality of carbon nanotube yarns 3 is, for example, 5 / cm ² or more, preferably 10 / cm ² or more, for example, 1800 / cm ² or less, per unit area of the surface 2A of the matrix 2. Preferably, it is 400 / cm ² or less.

  If the density of the carbon nanotube yarn 3 is not less than the above lower limit, the carbon nanotube composite material 1 can be reliably imparted with thermal conductivity and electrical conductivity, and if the density of the carbon nanotube yarn 3 is not more than the above upper limit, In the carbon nanotube composite material 1, the characteristics of the matrix 2 can be reliably ensured. Further, by changing the density of the carbon nanotube yarn 3, the thermal conductivity and electrical conductivity of the carbon nanotube composite material 1 can be appropriately adjusted.

  Further, the mass ratio of the carbon nanotube yarns 3 (when there are a plurality of carbon nanotube yarns 3, the total mass ratio thereof) is, for example, 0.01% by mass or more with respect to 100% by mass of the carbon nanotube composite material 1. , Preferably 0.20% by mass or more, for example, 8.96% by mass or less, preferably 3.79% by mass or less. For example, 0.01 part by mass or more with respect to 100 parts by mass of the matrix 2 The amount is preferably 0.20 parts by mass or more, for example, 9.84 parts by mass or less, and preferably 3.94 parts by mass or less.

2. Next, a method for manufacturing the carbon nanotube composite material 1 will be described. In order to manufacture the carbon nanotube composite material 1, first, as shown in FIG. 4A, a matrix 2 and carbon nanotube yarns 3 are prepared.

  The matrix 2 is appropriately selected depending on the use of the carbon nanotube composite material 1. For example, when the carbon nanotube composite material 1 is a heat conductive sheet, the matrix 2 made of silicone rubber or a fluorine-based polymer and having a sheet shape is selected. When the carbon nanotube composite 1 is an electrically conductive sheet, a matrix 2 similar to the thermally conductive sheet is selected, and a matrix 2 having a sheet shape is selected. Such a matrix 2 can also use a commercial item.

  In order to prepare the carbon nanotube yarn 3, for example, as shown in FIGS. 2A to 3A, a plurality of carbon nanotubes 5 that are vertically oriented on the substrate 9 are grown by chemical vapor deposition (CVD). After that, the plurality of carbon nanotube single yarns 4 are pulled out from the plurality of carbon nanotubes 5 to bundle the plurality of carbon nanotube single yarns 4.

  More specifically, as shown in FIG. 2A, first, a substrate 9 is prepared. The board | substrate 9 is not specifically limited, For example, the well-known board | substrate used for CVD method is mentioned, A commercial item can be used.

  Specific examples of the substrate 9 include a silicon substrate, a stainless steel substrate 12 on which a silicon dioxide film 11 is laminated, and preferably a stainless steel substrate 12 on which a silicon dioxide film 11 is laminated. 2A to 2D and FIG. 3A show a case where the substrate 9 is a stainless steel substrate 12 on which a silicon dioxide film 11 is laminated.

  Then, as shown in FIG. 2A, a catalyst layer 13 is formed on the substrate 9, preferably on the silicon dioxide film 11. In order to form the catalyst layer 13 on the substrate 9, a metal catalyst is formed on the substrate 9 (preferably the silicon dioxide film 11) by a known film formation method.

  As a metal catalyst, iron, cobalt, nickel etc. are mentioned, for example, Preferably, iron is mentioned. Such metal catalysts can be used alone or in combination of two or more. Examples of the film forming method include vacuum evaporation and sputtering, and preferably vacuum evaporation.

  As a result, the catalyst layer 13 is disposed on the substrate 9. When the substrate 9 is the stainless steel substrate 12 on which the silicon dioxide film 11 is laminated, the silicon dioxide film 11 and the catalyst layer 13 are, for example, a silicon dioxide precursor as described in JP-A-2014-94856. The mixed solution in which the body solution and the metal catalyst precursor solution are mixed is applied to the stainless steel substrate 12, and then the mixed solution is phase-separated and then dried to be simultaneously formed.

  Next, the substrate 9 on which the catalyst layer 13 is disposed is heated to, for example, 700 ° C. or more and 900 ° C. or less as shown in FIG. 2B. Thereby, the catalyst layer 13 is aggregated to form a plurality of granular bodies 13A.

  Then, a source gas is supplied to the heated substrate 9 as shown in FIG. 2C. The source gas contains a hydrocarbon gas having 1 to 4 carbon atoms (lower hydrocarbon gas). Examples of the hydrocarbon gas having 1 to 4 carbon atoms include methane gas, ethane gas, propane gas, butane gas, ethylene gas, and acetylene gas, and preferably acetylene gas.

  The source gas can also contain hydrogen gas, an inert gas (for example, helium, argon, etc.), water vapor, or the like, if necessary.

  When the source gas contains hydrogen gas or inert gas, the concentration of the hydrocarbon gas in the source gas is, for example, 1% by volume or more, preferably 30% by volume or more, for example, 90% by volume or less, preferably 50% by volume. % Or less. The supply time of the source gas is, for example, 1 minute or longer, preferably 5 minutes or longer, for example, 60 minutes or shorter, preferably 30 minutes or shorter.

  As a result, a plurality of carbon nanotubes 5 grow from each of the plurality of granular bodies 13A. In FIG. 2C, for convenience, it is described that one carbon nanotube 5 grows from one granular body 13A, but the present invention is not limited to this, and a plurality of carbon nanotubes 5 are formed from one granular body 13A. You may grow up.

  Each of the plurality of carbon nanotubes 5 extends in the thickness direction of the substrate 9 so as to be substantially parallel to each other on the substrate 9. That is, the plurality of carbon nanotubes 5 are oriented (orientated vertically) so as to be orthogonal to the substrate 9.

  As a result, a carbon nanotube aggregate 10 including a plurality of carbon nanotubes 5 is formed on the substrate 9.

  As shown in FIG. 3A, such a carbon nanotube aggregate 10 includes a plurality of rows 10A in the horizontal direction in which a plurality of carbon nanotubes 5 are linearly arranged in the vertical direction. Thereby, the carbon nanotube aggregate 10 is formed in a substantially sheet shape.

In the carbon nanotube aggregate 10, the bulk density of the plurality of carbon nanotubes 5 is, for example, 10 mg / cm ³ or more, preferably 20 mg / cm ³ or more, for example, 60 mg / cm ³ or less, preferably 50 mg / cm ³ or less. It is. The bulk density of the carbon nanotubes 5 is, for example, the mass per unit area (weight per unit: mg / cm ² ) and the length of the carbon nanotube (SEM (manufactured by JEOL Ltd.)) or a non-contact film thickness meter (Keyence Corporation). Measured by).

  Next, as shown in FIG. 2D, a plurality of carbon nanotube single yarns 4 are pulled out from the carbon nanotube aggregate 10.

  In order to pull out a plurality of carbon nanotube single yarns 4 from the carbon nanotube aggregate 10, for example, the carbon nanotubes 5 positioned at the longitudinal ends of each row 10A in the carbon nanotube aggregate 10 are collectively collected by a drawing tool (not shown). And is pulled in a direction intersecting the thickness direction of the substrate 9, preferably in the vertical direction.

Then, the pulled carbon nanotubes 5 are pulled out from the corresponding granular material 13A. At this time, the carbon nanotubes 5 adjacent to the carbon nanotubes 5 to be pulled out have one end (upper end) of the carbon nanotubes 5 pulled out due to frictional force and van der Waals force with the carbon nanotubes 5 to be pulled out. It is attached to the other end (lower end) and pulled out from the corresponding granular material 13A.
Thereby, a plurality of carbon nanotubes 5 are successively drawn out from the carbon nanotube aggregate 10 to form a carbon nanotube single yarn 4 in which the plurality of carbon nanotubes 5 are continuously connected.

  More specifically, in the carbon nanotube single yarn 4, the continuous carbon nanotube 5 has the other end (lower end) of the preceding carbon nanotube 5 attached to one end (upper end) of the next continuous carbon nanotube 5.

  The drawing speed of the carbon nanotube single yarn 4 is, for example, 10 mm / min or more, preferably 30 mm / min or more, for example, 100 mm / min or less, preferably 70 mm / min or less.

  As described above, a plurality of carbon nanotube single yarns 4 are simultaneously pulled out from the carbon nanotube aggregate 10 at the same time.

  Next, a plurality of carbon nanotube single yarns 4 are bundled to prepare a carbon nanotube yarn 3. As a method of bundling a plurality of carbon nanotube single yarns 4, for example, when the carbon nanotube yarns 3 are non-twisted yarns, a method of passing the plurality of carbon nanotube single yarns 4 through a die having a hole (for example, Japanese Patent Application Laid-Open No. 2014-2014). And the like, and when the carbon nanotube yarn 3 is a twisted yarn, a method of twisting a plurality of single carbon nanotube yarns 4 is mentioned. In such a method, Preferably, the method of twisting together the several carbon nanotube single yarn 4 is mentioned.

  The method of twisting the plurality of carbon nanotube single yarns 4 is continuously performed by the spinning device 20, for example, as shown in FIG. 3A. The spinning device 20 includes a supply unit 21 and a collection unit 22 that is disposed with a space from the supply unit 21. In the following description of the spinning device 20, the direction in which the supply unit 21 and the collection unit 22 face each other is referred to as the front-rear direction, and the direction orthogonal to the front-rear direction is referred to as the left-right direction.

  The supply unit 21 is disposed in the rear portion of the spinning device 20 and is configured to send the carbon nanotube yarn 3 toward the collection unit 22. The supply unit 21 includes a carbon nanotube support 8, a drawing tool (not shown), and a converging unit 23.

  The carbon nanotube support 8 includes a substrate 9 and a carbon nanotube aggregate 10. And the carbon nanotube support body 8 is arrange | positioned so that the vertical direction of the carbon nanotube aggregate 10 may follow a front-back direction.

  The converging part 23 is disposed between the carbon nanotube support 8 and the recovery part 22. The converging part 23 includes a support plate 24 and a pair of shaft parts 25.

  The support plate 24 has a plate shape that is substantially rectangular in plan view and extends in the left-right direction. The pair of shaft portions 25 are arranged on the upper surface of the support plate 24 with a slight space therebetween in the left-right direction. Each of the pair of shaft portions 25 has a substantially cylindrical shape extending in the vertical direction, and is supported by the support plate 24 so as to be relatively rotatable around the axis.

  The collection unit 22 is disposed in the front portion of the spinning device 20 and is configured to collect the carbon nanotube yarn 3 fed from the supply unit 21. The collection unit 22 includes a rotation unit 26, a collection shaft 27, a shaft drive unit 28, and a rotation drive unit 29.

  The rotating part 26 has a substantially U-shape that is open toward the rear side. The collection shaft 27 is disposed between the left and right side walls of the rotating unit 26. The collection shaft 27 has a substantially columnar shape extending in the left-right direction, and is rotatably supported on the left and right side walls of the rotating portion 26.

  The shaft driving unit 28 is configured to supply driving force to the recovery shaft 27 when electric power is supplied from the outside. The shaft drive unit 28 includes a motor shaft 28A and a drive transmission belt 28B.

  The motor shaft 28 </ b> A is disposed between the front wall of the rotating unit 26 and the recovery shaft 27, and is rotatably supported on the right side wall of the rotating unit 26. The motor shaft 28A rotates when a driving force is input from a motor body (not shown). The drive transmission belt 28B is a known endless belt, and spans between the right end portion of the motor shaft 28A and the right end portion of the recovery shaft 27.

  The rotation drive unit 29 is configured to supply driving force to the rotation unit 26 when electric power is supplied from the outside. The rotation drive unit 29 is disposed on the front side with respect to the rotation unit 26.

  The rotation drive unit 29 is made of, for example, a known motor, and includes a motor main body 29A and a motor shaft 29B that is rotatably supported by the motor main body 29A. The rear end portion of the motor shaft 29B is fixed to the center in the left-right direction of the front wall of the rotating portion 26. As a result, the rotating unit 26 can rotate around the motor shaft 29B, that is, the axis along the front-rear direction.

  In such a spinning device 20, a plurality of carbon nanotube single yarns 4 are pulled out from the carbon nanotube aggregate 10 by a drawing tool (not shown). Then, the plurality of carbon nanotube single yarns 4 are passed between the pair of shaft portions 25. At this time, each of the pair of shaft portions 25 is driven to rotate by rubbing against the plurality of carbon nanotube single yarns 4.

  Thereby, the plurality of carbon nanotube single yarns 4 are bundled in a linear shape (yarn shape). Then, the front end portions of the bundled carbon nanotube single yarns 4 are fixed to the collection shaft 27 of the collection unit 22.

  Next, power is supplied to the rotation drive unit 29 and power is supplied to the shaft drive unit 28. Then, the motor shaft 29B and the rotation unit 26 of the rotation drive unit 29 rotate in the clockwise direction when viewed from the front side, and the motor shaft 28A and the recovery shaft 27 of the shaft drive unit 28 rotate in the clockwise direction when viewed from the left side. To do.

  As a result, the plurality of carbon nanotube single yarns 4 are continuously pulled out from the carbon nanotube aggregate 10, bundled in the converging portion 23, then rotated clockwise and twisted together as viewed from the front side, while facing the front side. And is wound around the collecting shaft 27.

  Thus, the carbon nanotube yarn 3 that is a twisted yarn is prepared (prepared) by the spinning device 20.

  At this time, the rotation speed (circumferential speed) of the rotating unit 26 is, for example, 1000 rpm or more, preferably 2000 rpm or more, for example, 5000 rpm or less, preferably 4000 rpm or less.

  Further, the moving speed of the carbon nanotube yarn 3 due to the rotation of the collection shaft 27 is, for example, 0.1 m / min or more, preferably 0.5 m / min or more, for example, 10 m / min or less, preferably 6.0 m. / Min or less.

  Next, as shown in FIGS. 4A to 4C, the carbon nanotube yarn 3 is combined with the matrix 2. Specifically, the carbon nanotube yarn 3 is penetrated through the matrix 2 in the thickness direction. Examples of the method for causing the carbon nanotube yarns 3 to penetrate the matrix 2 include a method for sewing the carbon nanotube yarns 3 to the matrix 2.

  The method for sewing the carbon nanotube thread 3 is not particularly limited, and examples thereof include normal stitching, half reverse stitching, permanent reverse stitching, and preferably normal stitching.

  In order to sew the carbon nanotube thread 3 on the matrix 2 by stitching, for example, as shown in FIGS. 4A and 4B, the single carbon nanotube thread 3 is passed through the needle hole of the sewing needle 31 so as to be doubled. The sewing needle 31 is penetrated through the matrix 2 in the thickness direction.

  Thereby, the carbon nanotube yarn 3 penetrates the matrix 2 so as to follow the thickness direction of the matrix 2. At this time, the carbon nanotube yarn 3 penetrating the matrix 2 is brought into close contact with the matrix 2 by the elastic force of the matrix 2. Then, the carbon nanotube yarns 3 are sequentially penetrated through the matrix 2 a plurality of times.

  Further, as shown in FIGS. 5A and 5B, the carbon nanotube yarn 3 can be sewn to the matrix 2 by a sewing machine.

  More specifically, the carbon nanotube yarn 3 is wound around the bobbin 33 as the lower yarn, and the upper yarn 37 is passed through the needle hole of the sewing needle 30. The upper thread 37 is not particularly limited, and may be, for example, the carbon nanotube thread 3 or a known sewing thread. Then, the tension of the upper thread 37 is adjusted and the sewing machine is driven so that the lower thread (carbon nanotube thread 3) penetrates the matrix 2 and is exposed from the surface 2A of the matrix 2. Thereby, the carbon nanotube thread | yarn 3 penetrates the matrix 2 in multiple times so that the thickness direction of the matrix 2 may be followed.

  As a result, a plurality of portions of the carbon nanotube yarn 3 penetrate the matrix 2 in the same thickness direction as shown in FIGS. 4B and 5A.

  Next, as shown in FIG. 4C and FIG. 5B, the carbon nanotube yarn 3 is cut so that a plurality of portions penetrating the matrix 2 are separated from each other. More specifically, in the carbon nanotube yarn 3, the other end portions are so arranged that the first end 3 </ b> B protrudes from the front surface 2 </ b> A of the matrix 2 and the second end 3 </ b> C protrudes from the back surface 2 </ b> B of the matrix 2. It is removed by cutting with the cutting blade 32. As shown in FIG. 5B, when the carbon nanotube thread 3 is sewn to the matrix 2 by the sewing machine, the upper thread 37 is also removed.

  Thereby, a plurality of portions of the carbon nanotube yarn 3 penetrating the matrix 2 are separated from each other, and one carbon nanotube yarn 3 is cut into a plurality of carbon nanotube yarns 3 independent of each other. The plurality of carbon nanotube yarns 3 include (consists of) a plurality of carbon nanotube yarn bundles 6 as described above.

  Thus, the carbon nanotube composite material 1 including the matrix 2 and the plurality of carbon nanotube yarns 3 (the plurality of carbon nanotube yarn bundles 6) is manufactured.

  Examples of the use of the carbon nanotube composite material 1 include a heat conductive sheet, an electric conductive sheet, and an electromagnetic wave absorber, and preferably include a heat conductive sheet and an electric conductive sheet.

  When the carbon nanotube composite material 1 is used as a heat conductive sheet, for example, the carbon nanotube composite material 1 is provided in an electronic element unit 34 as shown in FIG. 9A. The electronic element unit 34 includes an electronic element 35 and a heat sink 36 in addition to the carbon nanotube composite material 1. The carbon nanotube composite material 1 is sandwiched between the electronic element 35 and the heat sink 36 so that the carbon nanotube yarns 3 are in contact with the electronic element 35 and the heat sink 36, respectively.

  In such an electronic element unit 34, when the electronic element 35 generates heat, the heat from the electronic element 35 is transmitted to the heat sink 36 through the carbon nanotube thread 3 of the carbon nanotube composite material 1.

  Further, when the carbon nanotube composite material 1 is used as an electrically conductive sheet, for example, the carbon nanotube composite material 1 is provided in the wearable biosensor 39. The wearable biosensor 39 includes a sensor body 41 and a gel pad 40 in addition to the carbon nanotube composite material 1. In this case, the matrix 2 of the carbon nanotube composite material 1 is made of a flexible resin material (for example, a thermosetting elastomer such as silicone rubber). Moreover, although not shown in figure, the gel pad 40 has a contact part which consists of metals. The carbon nanotube composite material 1 is sandwiched between the gel pad 40 and the sensor body 41 so that the carbon nanotube yarns 3 are in contact with the contact portion of the gel pad 40 and the sensor body 41, respectively.

  Such a wearable biosensor 39 is attached to the detection target 42 such that the contact portion of the gel pad 40 contacts the detection target 42 (for example, a detection target person). At this time, the gel pad 40 is elastically deformed along the detection target 42, and the carbon nanotube composite material 1 is elastically deformed so as to follow the elastic deformation of the gel pad 40. Even in this state, the contact portion of the gel pad 40 and the sensor main body 41 are electrically connected via the carbon nanotube thread 3 of the carbon nanotube composite material 1.

3. In the carbon nanotube composite material 1, since the tensile elastic modulus E at 25 ° C. of the matrix 2 is 5 GPa or less as shown in FIG. 1B, the carbon nanotube yarn 3 can penetrate the matrix 2. Since the tensile elastic modulus E at 25 ° C. is 0.01 GPa or more, the matrix 2 can be brought into close contact with the carbon nanotube yarn 3 penetrating the matrix 2 by its elastic force. Therefore, while the matrix 2 and the carbon nanotube thread 3 can be reliably combined, the matrix 2 can reliably hold the carbon nanotube thread 3, and the carbon nanotube thread 3 can be prevented from falling off the matrix 2.

  And since the carbon nanotube thread | yarn 3 has penetrated the matrix 2 in the thickness direction, in the thickness direction of the matrix 2, each improvement of the thermal conductivity of the carbon nanotube composite material 1 and electrical conductivity can be aimed at accurately. .

  In the carbon nanotube single yarn 4, as shown in FIG. 2D, a plurality of carbon nanotubes 5 are continuously connected in the extending direction thereof. Therefore, in the carbon nanotube single yarn 4, the plurality of carbon nanotubes 5 are aligned along the extending direction of the carbon nanotube single yarn 4.

  As a result, in the carbon nanotube yarn 3 in which the plurality of carbon nanotube single yarns 4 are bundled, the orientation of the carbon nanotubes 5 can be reliably ensured.

  The carbon nanotube yarn 3 is a twisted yarn in which a plurality of carbon nanotube single yarns 4 are twisted together as shown in FIG. 3A. Therefore, the strength of the carbon nanotube yarn 3 can be ensured, and the carbon nanotube yarn 3 can be surely penetrated into the matrix 2 as shown in FIGS. 4A and 4B.

  Further, as shown in FIG. 1B, the carbon nanotube yarns 3 penetrate a plurality of the matrix 2 in the same thickness direction. Therefore, in the thickness direction of the matrix 2, it is possible to reliably improve the thermal conductivity and the electrical conductivity of the carbon nanotube composite material 1.

  As shown in FIG. 4C, the carbon nanotube yarn 3 is cut so that a plurality of portions penetrating the matrix 2 are separated from each other. Therefore, a plurality of carbon nanotube single yarns 4 are exposed at the cut surface of the carbon nanotube yarn 3.

  As a result, the plurality of carbon nanotube single yarns 4 of the carbon nanotube yarn 3 can be efficiently used for heat conduction and / or electric conduction, and consequently the heat conduction of the carbon nanotube composite material 1 in the thickness direction of the matrix 2. Further improvement of each of the electrical conductivity and the electrical conductivity can be achieved.

  The carbon nanotubes 5 are multi-walled carbon nanotubes 5 in which a plurality of graphene sheets are laminated in the radial direction, as shown in FIG. 4E. And since the carbon nanotube thread | yarn 3 is cut | disconnected, in the cut surface of the carbon nanotube thread | yarn 3, each layer (each graphene sheet) of the multi-walled carbon nanotube 5 is exposed. Therefore, each layer of the multi-walled carbon nanotube 5 can be used for heat conduction and / or electric conduction, and thus, in the thickness direction of the matrix 2, each of the heat conductivity and electric conductivity of the carbon nanotube composite material 1 is further increased. Can be improved.

  Further, in the method for manufacturing the carbon nanotube composite material 1, as shown in FIG. 4B, the tensile elastic modulus E at 25 ° C. of the matrix 2 is 5 GPa or less, so that the carbon nanotube yarn 3 is penetrated through the matrix 2 in a predetermined direction. Since the tensile elastic modulus E at 25 ° C. of the matrix 2 is 0.01 GPa or more, the matrix 2 can reliably hold the carbon nanotube yarn 3. Therefore, the carbon nanotube yarn 3 can be accurately aligned in a desired direction. As a result, excellent thermal conductivity and electrical conductivity can be imparted to the matrix 2 in a desired direction.

  Therefore, the carbon nanotube composite material 1 having excellent thermal conductivity and electrical conductivity can be produced in a desired direction while being a simple method.

  Further, as shown in FIG. 2D, the carbon nanotube single yarn 4 is drawn out from a carbon nanotube aggregate 10 including a plurality of carbon nanotubes 5 oriented perpendicular to the substrate 9. Therefore, the plurality of carbon nanotubes 5 are oriented in the carbon nanotube single yarn 4 so as to be along the extending direction of the carbon nanotube single yarn 4.

As a result, in the carbon nanotube yarn 3 in which the plurality of carbon nanotube single yarns 4 are bundled, the orientation of the carbon nanotubes 5 can be reliably ensured.
4). 2nd Embodiment-7th Embodiment Next, 2nd Embodiment-7th Embodiment of the carbon nanotube composite material 1 of this invention is described with reference to FIG. 6A-FIG. In the second embodiment to the seventh embodiment, the same members as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

(1) Second Embodiment In the first embodiment, as shown in FIG. 1B, the carbon nanotube yarn bundle 6 has two carbon nanotube yarns 3. However, the present invention is not limited to this, and the second embodiment The carbon nanotube yarn bundle 6 has three or more carbon nanotube yarns 3 as shown in FIG. 6A. In this case, for example, in the step of compounding the carbon nanotube yarns 3 into the matrix 2, a plurality of carbon nanotube yarns 3 are passed through the needle holes of the sewing needles 31, passed through the matrix 2, and then cut as described above. .

  According to such 2nd Embodiment, the improvement per unit area of the matrix 2 of the some carbon nanotube thread | yarn 3 can be aimed at reliably. Also according to the second embodiment, the same effects as those of the first embodiment can be achieved.

(2) Third Embodiment In the first embodiment, as shown in FIG. 1B, the carbon nanotube yarns 3 penetrate the matrix 2 having a sheet shape in the thickness direction. In the embodiment, as shown in FIG. 6B, the carbon nanotube yarn 3 penetrates the matrix 2 having a sheet shape in the surface direction (longitudinal direction or lateral direction). In this case, the surface direction of the matrix 2 corresponds as an example of the predetermined direction. Also according to the third embodiment, it is possible to achieve the same operational effects as those of the first embodiment.

(3) Fourth Embodiment In the first embodiment, as shown in FIG. 1B, a plurality of carbon nanotube yarn bundles 6 penetrate the matrix 2 having a sheet shape along the thickness direction so as to be parallel to each other. However, the plurality of carbon nanotube yarn bundles 6 are not limited to this as long as they penetrate the matrix 2 in the thickness direction. For example, in the fourth embodiment, as shown in FIG. 6C, each of the plurality of carbon nanotube yarn bundles 6 penetrates the matrix 2 in the thickness direction so as to intersect the thickness direction of the matrix 2, and is in different directions. It extends. Also according to the fourth embodiment, the same operational effects as those of the first embodiment can be obtained.

  Moreover, in FIG. 1B, FIG. 4C, and FIG. 5B-FIG. 7, although the several carbon nanotube thread | yarn 3 which each carbon nanotube thread bundle 6 has is mutually parallel, it is not limited to this, Each carbon nanotube thread bundle 6 has The plurality of carbon nanotube yarns 3 may extend in different directions.

(4) Fifth Embodiment In the first embodiment, the matrix 2 has a sheet shape as shown in FIG. 1A. However, the present invention is not limited to this, and in the fifth embodiment, as shown in FIG. Has a prismatic shape.

  Further, the plurality of carbon nanotube yarns 3 may penetrate the matrix 2 in a plurality of directions. Thereby, the thermal conductivity and electrical conductivity of the carbon nanotube composite material 1 can be improved in a plurality of different directions. In addition, the fifth embodiment can provide the same effects as the first embodiment.

(5) Sixth Embodiment In the sixth embodiment, a resin material is attached to the carbon nanotube yarn 3 as shown in FIG. The resin material is not particularly limited, and examples thereof include the resin materials described above, preferably a thermoplastic resin, and more preferably polyvinyl alcohol.

  In order to attach the resin material to the carbon nanotube yarn 3, for example, the carbon nanotube yarn 3 is immersed in a resin-containing liquid containing the resin material (for example, a resin solution in which the resin material is dissolved) and then dried.

  In such a case, the spinning device 20 includes an immersion unit 45 and a drying unit 46.

  The immersion part 45 is disposed between the converging part 23 and the recovery part 22. The immersion unit 45 includes an immersion tank 47 and a plurality of rollers 48. The immersion tank 47 has a substantially box shape opened upward, and a resin-containing liquid is stored therein. Each of the plurality of rollers 48 is appropriately disposed at a predetermined position so that the carbon nanotube yarn 3 (the plurality of carbon nanotube single yarns 4) is immersed in the resin-containing liquid in the immersion tank 47.

  The drying unit 46 is disposed between the immersion unit 45 and the collection unit 22. The drying unit 46 is a known dryer and is configured such that the carbon nanotube yarn 3 passes through the drying unit 46.

  As a result, the carbon nanotube yarn 3 (the plurality of carbon nanotube single yarns 4) is immersed in the resin-containing liquid in the immersion tank 47 and then dried when passing through the drying unit 46. Is attached (supported).

  Further, the resin material can be attached to the carbon nanotube yarn 3 by electrospinning the polymer solution in which the polymer material is dissolved in the carbon nanotube yarn 3.

  The timing for attaching the resin material to the carbon nanotube yarn 3 is not particularly limited as long as it is before the carbon nanotube yarn 3 is combined with the matrix 2.

  According to the sixth embodiment, since the resin material is attached to the carbon nanotube yarn 3, when the carbon nanotube yarn 3 is combined with the matrix 2, the resistance (friction force) acting between them is improved. Can be planned. Therefore, in the carbon nanotube composite material 1, the carbon nanotube yarn 3 can be reliably suppressed from falling off from the matrix 2. As a result, the thickness of the matrix 2 can be reduced, and as a result, the thermal conductivity of the carbon nanotube composite material 1 can be further improved.

  Further, the carbon nanotube yarn 3 can be surface-treated before the carbon nanotube yarn 3 is combined with the matrix 2. Examples of the surface treatment of the carbon nanotube yarn 3 include plasma treatment and UV treatment. Thereby, the surface of the carbon nanotube yarn 3 can be modified. Therefore, in the carbon nanotube composite material 1, the resistance (friction force) acting between the carbon nanotube yarns 3 and the matrix 2 can be improved.

  In addition, the sixth embodiment can provide the same operational effects as the first embodiment.

5). Modification In the first embodiment, as shown in FIG. 4C, the carbon nanotube yarn 3 is cut so that a plurality of portions penetrating the matrix 2 are separated from each other. However, the carbon nanotube yarn 3 is not limited to this. 3, as shown in FIG. 4B, a plurality of portions penetrating the matrix 2 may be continuous with each other.

  That is, the carbon nanotube yarn 3 is a continuous yarn that penetrates through the matrix 2 and is continuous. However, in such a carbon nanotube composite material 1, only the carbon nanotube single yarn 4 exposed on the surface of the carbon nanotube yarn 3 among the plurality of carbon nanotube single yarns 4 of the carbon nanotube yarn 3 is in contact with other members. . Furthermore, when the carbon nanotube 5 is the multi-walled carbon nanotube 5, only the outermost layer (graphene sheet) of the multi-walled carbon nanotube 5 is in contact with other members.

  As a result, the inner (center portion) carbon nanotube single yarn 4 that is not exposed on the surface of the carbon nanotube yarn 3 and the radially inner layer (graphene sheet) of the multi-walled carbon nanotube 5 can be thermally and / or electrically conductive. Because it cannot be used effectively. Therefore, 1st Embodiment is more preferable than this modification.

  In the first embodiment, as shown in FIG. 1A, the plurality of carbon nanotube yarn bundles 6 are arranged at intervals, but the present invention is not limited to this, and the plurality of carbon nanotube yarns 3 are spaced from each other one by one. It may be arranged with a gap.

  In the first embodiment, the plurality of carbon nanotube yarns 3 are uniformly held throughout the matrix 2, but may be held only in a part of the matrix 2. In this case, the area of the region of the matrix 2 holding the carbon nanotube yarns 3 is, for example, 10% or more, preferably 30% or more, for example 90% or less, preferably with respect to the area of the surface 2A of the matrix 2 80% or less.

  In the first embodiment, both end portions of the carbon nanotube yarn 3 protrude from the matrix 2, but the carbon nanotube yarn 3 is not particularly limited as long as the carbon nanotube yarn 3 penetrates the matrix 2 in a predetermined direction. 3 may be flush with the front surface 2A and the back surface 2B of the matrix 2, respectively. Further, either one of both end portions of the carbon nanotube yarn 3 may protrude from the matrix 2, and the other end surface may be flush with the front surface (back surface) of the matrix 2.

  In the first embodiment, a plurality of carbon nanotube yarns 3 are passed through the matrix 2 and then cut so that a plurality of portions passing through the matrix 2 are separated from each other. Each time the nanotube yarn 3 is passed through the matrix 2, the carbon nanotube yarn 3 may be cut so as to have a predetermined length L, and this may be repeated a plurality of times.

  In the first embodiment, a plurality of carbon nanotube single yarns 4 are pulled out from the carbon nanotube aggregate 10 at once. However, the carbon nanotube single yarn 4 is extracted from the carbon nanotube aggregate 10 one by one multiple times. It can also be pulled out.

  These 1st Embodiment-6th Embodiment and a modification can be combined suitably.

  The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to them. Specific numerical values such as blending ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned “Mode for Carrying Out the Invention”, and the corresponding blending ratio (content ratio) ), Physical property values, parameters, etc. The upper limit value (numerical value defined as “less than” or “less than”) or lower limit value (number defined as “greater than” or “exceeded”) may be substituted. it can.

Example 1
After a silicon dioxide film was laminated on a stainless steel substrate, iron was deposited as a catalyst layer on the silicon dioxide film. The lateral dimension of the substrate is 3 cm, the longitudinal dimension of the substrate is 12 cm, and the thickness of the substrate is 50 μm.

Next, the substrate was heated to a predetermined temperature, and a source gas (acetylene gas) was supplied to the catalyst layer. As a result, a carbon nanotube aggregate having a substantially rectangular shape in plan view was formed on the substrate. In the aggregate of carbon nanotubes, the plurality of carbon nanotubes extend so as to be substantially parallel to each other, and are aligned (vertically aligned) so as to be orthogonal to the substrate. The average outer diameter of the carbon nanotubes was about 12 nm, the average length of the carbon nanotubes was about 200 μm, and the bulk density of the plurality of carbon nanotubes 5 in the aggregate of carbon nanotubes was about 40 mg / cm ³ .

  Then, in the carbon nanotube aggregate, a plurality of carbon nanotubes arranged at one end in the vertical direction were collectively held over the entire width by the drawing tool and pulled in the vertical direction. Thus, a plurality of carbon nanotube single yarns were drawn from the carbon nanotube aggregate on the carbon nanotube support. The diameter of each of the plurality of carbon nanotube single yarns was about 60 nm to 80 nm.

  Next, a plurality of carbon nanotube single yarns were twisted together by a spinning device shown in FIG. 3A to prepare carbon nanotube yarns as twisted yarns. The rotation speed of the rotating unit of the spinning device was 3000 rpm. Further, the moving speed of the carbon nanotube yarn due to the rotation of the collecting shaft was 3.5 m / min.

  Thus, a carbon nanotube yarn that is a twisted yarn was prepared. The diameter of the carbon nanotube yarn was about 50 μm.

  In addition, a circular silicone rubber sheet (matrix) was prepared. The diameter of the silicone rubber sheet is 50 mm, and the thickness of the silicone rubber sheet is 10 mm. The tensile elastic modulus E at 25 ° C. of the silicone rubber sheet is 0.09 GPa.

  And after passing the carbon nanotube thread | yarn through the needle hole of a sewing needle so that it might become double, it sewed so that a plurality of silicone rubber sheets might penetrate in the thickness direction. Next, the carbon nanotube yarn was cut so that a plurality of portions penetrating the silicone rubber sheet were separated from each other.

  Thus, a carbon nanotube composite material including a silicone rubber sheet and a plurality of carbon nanotube yarns was prepared. Both ends of the carbon nanotube yarn protruded from the matrix. In addition, the plurality of carbon nanotube yarns included a plurality of carbon nanotube yarn bundles each having a bundle shape, and the plurality of carbon nanotube yarn bundles were arranged at intervals of 2 mm in the longitudinal direction. A plurality of yarn bundle rows in which a plurality of carbon nanotube yarn bundles are linearly arranged are arranged in parallel at intervals of 2 mm in the lateral direction.

The density of the carbon nanotube yarn bundle was 10 bundles / cm ² per unit area of the silicone rubber sheet. That is, the density of the carbon nanotube yarn was 20 pieces / cm ² per unit area of the silicone rubber sheet.

Example 2
A carbon nanotube composite material was prepared in the same manner as in Example 1 except that the carbon nanotube yarn was sewn to the matrix so that the density of the carbon nanotube yarn bundle was 20 bundles / cm ² per unit area of the matrix. did. That is, the density of the carbon nanotube yarns was 40 / cm ² per unit area of the silicone rubber sheet.

Example 3
A carbon nanotube composite was prepared in the same manner as in Example 1 except that the silicone rubber sheet was changed to a square-shaped polytetrafluoroethylene sheet (matrix). The tensile modulus E at 25 ° C. of the polytetrafluoroethylene sheet is 0.55 GPa. The dimension of one side of the polytetrafluoroethylene sheet is 5 cm, and the thickness of the polytetrafluoroethylene sheet is 500 μm.

Example 4
A carbon nanotube yarn was prepared in the same manner as in Example 1. The carbon nanotube yarn was immersed in a 10% by mass polyvinyl alcohol solution and then dried to attach the polyvinyl alcohol to the carbon nanotube yarn.

  In addition, a square-shaped silicone rubber sheet (matrix) was prepared. The dimension of one side of the silicone rubber sheet is 5 cm, and the thickness of the silicone rubber sheet is 3 cm. The tensile elastic modulus E at 25 ° C. of the silicone rubber sheet is 0.09 GPa.

  Then, the carbon nanotube yarn to which the polyvinyl alcohol adhered was sewn to the silicone rubber sheet in the same manner as in Example 1, and then cut so that a plurality of portions penetrating the silicone rubber sheet were separated from each other.

Thus, a carbon nanotube composite material was prepared. The density of the carbon nanotube yarn was 20 / cm ² per unit area of the matrix.

Example 5
A carbon nanotube composite was prepared in the same manner as in Example 4 except that the square-shaped silicone rubber sheet was changed to a square-shaped polytetrafluoroethylene sheet (matrix). The tensile modulus E at 25 ° C. of the polytetrafluoroethylene sheet is 0.55 GPa. The dimension of one side of the polytetrafluoroethylene sheet is 5 cm, and the thickness of the polytetrafluoroethylene sheet is 500 μm.

Comparative Example 1
A circular silicone rubber sheet (matrix) was prepared. The diameter of the silicone rubber sheet is 50 mm, and the thickness of the silicone rubber sheet is 10 mm.

Measurement of thermal conductivity:
For the carbon nanotube composites of Examples 1 and 2 and the silicone rubber sheet of Comparative Example 1, the thermal conductivity in the thickness direction was measured with a thermal conductivity measuring device (trade name: T3Ster DynTIM Tester, manufactured by Mentor Graphics). did. The results are shown in Table 1 and FIG.

DESCRIPTION OF SYMBOLS 1 Carbon nanotube composite material 2 Matrix 3 Carbon nanotube thread 4 Carbon nanotube single thread 5 Carbon nanotube 9 Substrate 10 Carbon nanotube aggregate

Claims (4)

Preparing a carbon nanotube yarn having carbon nanotubes;
Preparing a matrix having a tensile modulus E at 25 ° C. of 0.01 GPa to 5 GPa and having a sheet shape;
A step of compounding the carbon nanotube yarn to said matrix, by sewing the carbon nanotube yarn to said matrix, a step of Ru passed through more than once in the same direction the carbon nanotube yarn to said matrix,
Wherein such plurality of portions separated from one another through said matrix in carbon nanotube yarn, characterized in including it and a step of cutting the carbon nanotube yarn, method of manufacturing the carbon nanotube composite. The step of preparing the carbon nanotube yarn includes
Preparing a carbon nanotube assembly comprising a plurality of carbon nanotubes disposed on a substrate and oriented perpendicular to the substrate;
From the carbon nanotube aggregate, a step of pulling out a plurality of carbon nanotube single yarns in which the plurality of carbon nanotubes are continuously connected in the extending direction of the carbon nanotubes;
The method for producing a carbon nanotube composite material according to claim 1, further comprising a step of bundling a plurality of carbon nanotube single yarns.   The method for producing a carbon nanotube composite according to claim 2, wherein in the step of bundling the plurality of carbon nanotube single yarns, the plurality of carbon nanotube single yarns are twisted to prepare a twisted yarn. The said carbon nanotube is a multi-walled carbon nanotube, The manufacturing method of the carbon nanotube composite material as described in any one of Claims 1-3 characterized by the above-mentioned.

Images