JP2010138305A - Carbon nanotube (cnt) compounded resin material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin material less in bubble residue, more enhanced in strength, and preferably improved in conductivity. <P>SOLUTION: The resin material comprises a matrix resin 4 in which a CNT material comprising a plurality of CNT 1 are compounded so as to impart mainly high strength to the resin material, wherein carbon particles 3 having an aspect ratio smaller than that of the CNT 1 are mixed into spaces of the CNT 1 in such a manner that the proportion of the particles is higher than the matrix resin 4 in the spaces. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a CNT-containing resin material in which a CNT material composed of a plurality of carbon nanotubes (CNT) is mixed in a matrix resin to enhance mechanical strength, and in particular, mechanical strength of the resin material and Preferably, it relates to further improving electrical or thermal conductivity.

  CNT is a shape in which a graphene sheet with carbon atoms arranged in a hexagonal shape is wound in a cylindrical shape, and has a substantially uniform diameter shape in the length direction. The aspect ratio, which is the ratio of length to diameter, is large and the diameter is fine. However, it has high mechanical strength and excellent electrical conductivity (see Patent Document 1). And by using this property, a CNT material composed of a plurality of CNTs is mixed with a resin material to form a CNT-blended resin material (hereinafter referred to as a resin material), and this resin material is made of a high-strength resin, a conductive resin, Development of applications such as transparent conductive films has been carried out.

  The resin material shown in FIG. 2 plays a role as a binding material in which the matrix resin 4 enters the gaps 2 between the plurality of CNTs 1 constituting the CNT material, and the matrix resin 4 bonds the plurality of CNTs 1 to each other. In this configuration, the mixing ratio of CNT1 is extremely high as compared with the matrix resin 4 due to the high strength, which is a characteristic of the resin material, or due to electric and thermal conductivity. What should be noted in this configuration is that bubbles 5 are mixed in the matrix resin 4.

  The method for producing this resin material will be described below. First, a CNT-containing resin solution is prepared by mixing a CNT dispersion solution and a matrix resin solution. In this case, in order to obtain high strength and high conductivity, the mixing ratio of CNTs is set higher than that of the matrix resin. And although the said solution is drained, since the mixing rate of CNT material is high, it becomes difficult for the matrix resin 4 to enter into the clearance gap 2 of CNT1 enough. Therefore, many bubbles 5 remain in the gap 2 of the CNT 1. In such a state, in the next liquid removal process, the bubbles 5 remaining in the gap 2 of the CNT 1 remain inside without being exposed to the outside even in the liquid removal action.

  In this way, as shown in FIG. 2, a resin material in which bubbles 5 remain is obtained. The bubbles 5 cause a significant decrease in the mechanical strength, electricity and thermal conductivity of the resin material.

On the other hand, when the mixing ratio of the CNTs 1 is lowered, the contact ratio between the CNTs 1 and the formation ratio of the gaps 2 between the CNTs 1 are also reduced, and the rate of remaining bubbles 5 in the liquid removal process is also reduced. It becomes difficult to obtain a conductive resin material. Therefore, while maintaining the mixing ratio of CNT1 high and maintaining high strength and high conductivity, in addition to greatly reducing the residual ratio of the bubbles 5, the strength and conductivity are further increased. Development of a resin material that can improve the properties is required, and the inventors of the present application have conducted intensive research.
JP 2001-303250 A

  The main problem to be solved by the present invention is to reduce the residual bubbles and at least increase the strength, preferably to improve the electrical and thermal conductivity. Other issues will be apparent from the following.

  The resin material according to the present invention is a resin material in which a CNT material composed of a plurality of carbon nanotubes (CNT) is blended in a matrix resin mainly for the purpose of imparting high strength to the resin material. A plurality of small carbon particles are mixed in the gaps so that the existence ratio is higher than that of the matrix resin in the gaps of the CNTs.

  The meaning of the “mainly” means that not only high strength but also the purpose of imparting high electrical conductivity and high thermal conductivity can be included. Carbon nanotubes are generally excellent in electrical and thermal conductivity, and the presence of the carbon particles in the gaps between the CNTs reduces the residual bubbles caused by the matrix resin, and assists the properties of the carbon nanotubes. it can.

  As described above, in the present invention, since the existence ratio of the carbon particles in the gaps of the CNTs is higher than that of the matrix resin, the resin material is inevitably reduced in the residual ratio of bubbles in the matrix resin. Therefore, in this invention, the resin material which the intensity | strength improved more than before can be provided.

  Specifically, the existence significance of CNT, carbon particles, and matrix resin will be described. First, regarding mechanical strength, CNT has high tensile strength. While the matrix resin has a role of adhering CNTs to each other, in the present invention, carbon particles are contained in the gaps between the CNTs at a higher ratio than the matrix resin, so that not only the tensile strength but also the compression, bending, and processing strength are not limited. It is extremely high. Therefore, it becomes possible to provide a resin material suitable for various uses such as a reinforced gear and a reinforced case. In addition, in terms of electrical conductivity, the presence of carbon particles in a high ratio in the gaps between CNTs increases the electrical conductivity due to the increased cross-sectional area that can contribute to electrical conductivity. Regarding the thermal conductivity, carbon particles are present in the gaps between the CNTs at a higher rate than the matrix resin, so that the matrix resin having a poor thermal conductivity is larger than the resin material existing in the gaps between the CNTs. , Its thermal conductivity is higher.

  In the resin material of the present invention, the gaps between the CNTs are almost completely filled with carbon particles. Therefore, when microfabrication is performed, voids due to the gaps between the CNTs hardly appear on the processed surface. It is suitable for materials of various workpieces that require minute machining accuracy.

  From the above, in the resin material of the present invention, it is possible to obtain a resin material that has higher strength than that of the conventional material and that has greatly improved conductivity.

  It is preferable that the resin material of the present invention further aims to impart high electrical conductivity or high thermal conductivity. In this case, it can be defined as volume resistivity (Ω · cm) for high electrical conductivity and thermal conductivity (W / m · k) for high thermal conductivity.

  In the present invention, the CNT constituting the CNT material may be a single-wall CNT or a multi-wall CNT. The CNT material of the present invention can be constituted by an assembly of a plurality of multilayer CNTs that grow by the action of catalyst fine particles on the substrate surface.

  The resin material of the present invention is not limited to its use, but as an example of use, as high strength, case material, pulley material, building material, etc., high electrical conductivity, electrostatic removal material, In addition, examples of the high thermal conductivity include a radiator material.

  The resin material of the present invention can be used for a transparent conductive film material that is transparent and has a light wavelength or less when it has high strength and high electrical conductivity, and preferably high thermal conductivity. This film material can be used, for example, for an anode electrode that attracts electrons from an electron field emission emitter.

  When the resin material of the present invention is used as a case material, for example, a mobile phone case material, it is possible to make a mobile phone case that is soft and lightweight and has high strength.

  Since the resin material of the present invention has a higher proportion of carbon particles in the gap between the CNTs than the matrix resin, the residual ratio of bubbles is lower than that of the conventional resin material, and accordingly, the strength is high, preferably high conductivity. The resin material can be provided.

  Hereinafter, a resin material according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a cross-sectional configuration of the resin material of the embodiment. Referring to FIG. 1, the resin material according to the embodiment has carbon particles 3 and matrix resin 4 entering gaps 2 between a plurality of CNTs 1 constituting the CNT material, while carbon particles in gaps 2 of CNT1. The presence ratio of 3 is higher than that of the matrix resin 4. Thereby, the presence of the bubbles 5 in the matrix resin 4 is small.

  The CNT 1 is a single-layer or multi-layer CNT, and can be composed of only a single-wall CNT, only a multi-wall CNT, or a mixed CNT of both. The size of the gap 2 of the CNT 1 is, for example, about 100 μm or less, and the average cross-sectional size of each carbon particle 3 in the gap 2 of the CNT 1 is about 0.1 μm to 200 μm. It is about 20 to 80% of the volume.

  Examples of the matrix resin 4 include impact resistance and elastomer. By application, for example, a resin having a high rigidity material can be preferably exemplified for impact resistant applications, and a resin having a viscosity or an elastic body can be preferably exemplified for applications such as an elastomer.

  The carbon particles 3 are particles having an aspect ratio smaller than that of CNTs and a particle diameter of submicron order, and the shape thereof is not limited to spherical, rectangular, linear, amorphous, etc. For example, amorphous carbon, graphite, carbon Black can be applied. Examples of the carbon black include ketjen black, acetylene black, SRF, GPF, FEF, HAF, ISAF, and SAF.

  In the resin material of the present embodiment, first, CNT1 has high tensile strength with respect to mechanical strength. The matrix resin 4 bonds the CNTs 1 to each other, but in the present invention, the carbon particles 3 are contained in a higher proportion in the gaps 2 of the CNTs 1 than the matrix resin 4, so that the compressive strength is extremely high. . Therefore, it becomes possible to provide a resin material suitable for the use of a reinforced gear or a reinforced case. In terms of electrical conductivity, the carbon particles 3 are present in the gaps 2 of the CNTs 1 in a higher proportion than the matrix resin 4, so that the electrical conductivity is higher. As for thermal conductivity, since the carbon particles 3 are present in the gap 2 of the CNT 1 at a higher ratio than the matrix resin 4, there are many matrix resins 4 inferior in thermal conductivity in the gap 2 of the CNT 1. The thermal conductivity is higher than that of the resin material.

  From the above, in the resin material of the present invention, it is possible to obtain a resin material that has higher strength than that of the conventional material and that has greatly improved conductivity.

  In addition, the said resin material can be manufactured with the following manufacturing method, for example. That is, in the mixing step of mixing the matrix resin solution and the CNT dispersion solution, the carbon particles are dispersed and mixed in the dispersion solution together with the CNTs, or alternatively, a solution different from the matrix resin solution and the CNT dispersion solution. A dispersion solution in which carbon particles are dispersed is mixed. Then, the resin material of the present invention is obtained by draining this mixed solution.

  The present invention is not limited to the above-described embodiment, and includes various changes or modifications within the scope described in the claims.

FIG. 1 is a cross-sectional view schematically showing a resin material according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a conventional resin material.

Explanation of symbols

1 CNT
2 CNT gap 3 Carbon particles 4 Matrix resin 5 Air bubbles

Claims (2)

  In a resin material in which a CNT material composed of a plurality of carbon nanotubes (CNT) is blended in a matrix resin for the purpose of mainly imparting high strength to the resin material, a plurality of carbon particles having an aspect ratio smaller than CNT are A CNT-containing resin material, characterized in that the CNT-containing resin material is mixed in the gap so that the abundance ratio is higher than that of the matrix resin in the gap of each CNT.   The CNT-containing resin material according to claim 1, wherein the carbon particles have high electrical conductivity and / or high thermal conductivity.

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