JP2019179727A - Carbon nanotube wire rod, carbon nanotube covered-electric wire, method for producing carbon nanotube wire rod, and method for processing carbon nanotube covered-electric wire - Google Patents

Abstract

An object of the present invention is to provide a carbon nanotube wire capable of easily and sufficiently removing an insulating coating layer of the carbon nanotube wire and improving the reliability of electrical connection with the outside. A CNT wire rod (10) is formed from a single CNT aggregate (11) composed of a plurality of CNTs (11a), (11a), or a bundle of a plurality of CNT aggregates (11). The CNT wire 10 has a plurality of impregnation suppressing portions that suppress the impregnation of the coating material constituting the insulating coating layer 21 that covers the CNT wire 10 into the CNT wire 10 over the entire outer circumferential portion of the CNT wire 10. 31, 31, ... are provided. [Selection diagram] Fig. 1

Description

  The present invention relates to a carbon nanotube wire composed of a plurality of carbon nanotubes, a carbon nanotube-covered electric wire obtained by coating the carbon nanotube wire with an insulating material, a method for producing a carbon nanotube wire, and a method for processing a carbon nanotube-covered electric wire.

  Carbon nanotubes are materials having various characteristics and are expected to be applied in many fields.

  For example, the CNT is a single layer of a cylindrical body having a hexagonal lattice network structure, or a three-dimensional network structure composed of multiple layers arranged substantially coaxially, and is lightweight, conductive and thermally conductive. Excellent properties such as properties and mechanical strength. However, it is not easy to turn CNT into a wire, and a technique for using CNT as a wire has not been proposed.

  In addition, when applying a carbon nanotube wire formed by bundling a plurality of carbon nanotube aggregates as a conductor from a single carbon nanotube aggregate formed by bundling a plurality of carbon nanotubes, In order to ensure insulation, a carbon nanotube-coated electric wire obtained by coating a carbon nanotube wire with an insulating material is used. When connecting a carbon nanotube-coated electric wire, for example, the insulating coating layer at the longitudinal end portion of the carbon nanotube-coated electric wire is removed to expose the longitudinal end portion of the carbon nanotube wire, and this exposed portion is connected to an external terminal or the like. Thus, electrical connection between the carbon nanotube-coated electric wire and the outside is performed.

  As a method for removing the insulating coating layer of the covered electric wire, for example, a plurality of core wires exposed from the upper side are introduced into the slits provided on both the fixed side plate and the movable side plate arranged opposite to each other. The structure which pulls out an edge part coating | coated part from a core wire is proposed by making both plates isolate | separate after latching a covering electric wire of a book (patent document 1).

  In addition, as a method of removing the coating of the metal-coated electric wire, a blade support is provided on the peeling head in a movable manner, and a plurality of peeling tools are arranged in parallel at different cutting depths on the blade support to support the blade. By moving the body, it is possible to peel off various types of covered electric wires with different thicknesses of the insulation coating layer with a small number of types of peeling blades by facing and combining the peeling blades provided on both peeling heads as appropriate. The structure which can do is proposed (patent document 2).

JP 09-182233 A JP 09-046844 A

  In the case of a carbon nanotube wire formed by bundling a plurality of aggregates of carbon nanotubes, such as a carbon nanotube stranded wire, the outer diameter of one carbon nanotube is extremely small, on the order of nanometers. However, it is difficult to remove the resin impregnated in the carbon nanotube stranded wire. For example, when a carbon nanotube stranded wire is coated with an insulating varnish, the insulating varnish impregnates between the carbon nanotubes or between the carbon nanotube aggregates, making it difficult to remove the coating. In addition, when an extrusion coating layer is formed on the carbon nanotube stranded wire, the adhesion between the insulating varnish and the resin of the extrusion coating layer becomes stronger due to the presence of burrs that cannot be removed, and the coating removal becomes even more difficult. It becomes.

  In addition, the above conventional technique is a general method for removing an insulation coating layer, or a coating removal method for a coated electric wire whose conductor is a metal wire, and is a carbon nanotube coating in which a carbon nanotube stranded wire is coated. It is not assumed that the wire is removed. For this reason, the insulating coating layer between the carbon nanotubes or between the carbon nanotube aggregates cannot be sufficiently removed, and the electrical connection reliability at the connection portion between the exposed portion and the external terminal is lowered.

  An object of the present invention is to provide a carbon nanotube wire, a carbon nanotube-coated electric wire, and a carbon nanotube that can easily and sufficiently remove the insulating coating layer of the carbon nanotube wire and can improve the reliability of electrical connection with the outside. An object of the present invention is to provide a method for manufacturing a nanotube wire and a method for processing a carbon nanotube-coated electric wire.

  In order to achieve the above object, the carbon nanotube wire of the present invention is a carbon nanotube formed from a single carbon nanotube aggregate composed of a plurality of carbon nanotubes or a bundle of a plurality of the carbon nanotube aggregates. One or more wire rods that suppress impregnation of the carbon nanotube wire with a coating material that forms an insulating coating layer covering the carbon nanotube wire material over the entire circumference in the outer circumferential portion of the carbon nanotube wire material The impregnation suppression part is provided.

  It is preferable that the impregnation suppressing part has a connection structure that connects the carbon nanotubes located in the outermost layer of the carbon nanotube wire.

  The plurality of impregnation suppressing portions may be intermittently disposed in the longitudinal direction of the carbon nanotube wire.

  It is preferable that the one or more impregnation suppressing portions are formed at least at the longitudinal ends of the carbon nanotube wire.

  The impregnation suppressing unit may be made of any material selected from conductive paste, plating, and solder.

  The carbon nanotube wire may further include one or a plurality of enamel-based resin coating portions provided on an outer peripheral portion of the carbon nanotube wire and disposed in a portion other than the impregnation suppressing portion.

  In order to achieve the above object, the carbon nanotube-covered electric wire of the present invention includes a carbon nanotube wire, an insulating coating layer covering the carbon nanotube wire, and the carbon nanotube wire between the carbon nanotube wire and the insulating coating layer. One or a plurality of impregnation suppression portions that suppress the impregnation of the coating material constituting the insulating coating layer into the carbon nanotube wire over the entire circumferential direction of the nanotube wire.

  In order to achieve the above object, the method for producing a coated wire of a carbon nanotube wire according to the present invention includes a coating that forms an insulating coating layer of the carbon nanotube wire on the entire outer circumferential portion of the carbon nanotube wire. Forming one or a plurality of impregnation suppressing portions for suppressing impregnation of the material into the carbon nanotube wire, and forming the insulating coating layer on the opposite side of the carbon nanotube wire with respect to the impregnation suppressing portion; It is characterized by having.

  In order to achieve the above object, a method of processing a coated wire of a carbon nanotube wire of the present invention includes a carbon nanotube wire, an insulating coating layer that covers the carbon nanotube wire, and the carbon nanotube wire and the insulating coating layer. A carbon nanotube-covered electric wire comprising one or a plurality of impregnation suppression portions that suppress impregnation of the coating material constituting the insulating coating layer into the carbon nanotube wire over the entire circumferential direction of the carbon nanotube wire The method is characterized in that the insulating coating layer formed on the opposite side of the carbon nanotube wire from the impregnation suppressing portion is removed.

  According to the present invention, one or a plurality of impregnation suppression portions are provided on the outer peripheral portion of the carbon nanotube wire over the entire circumferential direction, and the covering material constituting the insulating coating layer that covers the carbon nanotube wire Since the impregnation of the carbon nanotube wire is suppressed, when the insulating coating layer is formed on the side opposite to the carbon nanotube wire of the impregnation suppressing portion, the insulating coating layer is interposed between the carbon nanotubes or between the carbon nanotube aggregates. It becomes difficult to invade and it is difficult to leave behind the coating material. Therefore, the insulating coating layer can be easily and sufficiently removed, and the reliability of electrical connection with the outside can be improved.

It is a perspective view which shows the structure of the carbon nanotube covering electric wire which concerns on embodiment of this invention. It is a perspective view which shows the modification of the carbon nanotube wire in FIG. It is a perspective view which shows the other modification of the carbon nanotube wire in FIG. It is a flowchart which shows an example of the manufacturing method of the carbon nanotube covering electric wire of FIG.

  Hereinafter, the carbon nanotube covering electric wire concerning the embodiment of the present invention is explained, referring to drawings.

[Configuration of carbon nanotube-coated electric wire]
As shown in FIG. 1, a carbon nanotube-coated electric wire (hereinafter also referred to as “CNT-coated electric wire”) 1 according to an embodiment of the present invention includes a carbon nanotube wire (hereinafter also referred to as “CNT wire”) 10 and a CNT. Impregnation of the CNT wire 10 with the covering material constituting the insulating coating layer 21 over the entire circumferential direction of the CNT wire 10 between the insulating coating layer 21 covering the wire 10 and the CNT wire 10 and the insulating coating layer 21. And a plurality of impregnation suppressing portions 31, 31, 31 for suppressing the above.
The CNT-coated electric wire 1 has a configuration in which an insulating coating layer 21 is coated on the outer peripheral surface of a CNT wire 10. That is, the insulating coating layer 21 is formed along the longitudinal direction of the CNT wire 10. In the CNT-coated electric wire 1, the entire outer peripheral surface of the CNT wire 10 is covered with an insulating coating layer 21. Further, in the CNT-coated electric wire 1, the insulating coating layer 21 is in direct contact with the outer peripheral surface of the CNT wire 10 at a portion other than the portion where the impregnation suppressing portion 31 is formed. In FIG. 1, the CNT wire 10 is an element wire (single wire) made of one CNT wire 10, but the CNT wire 10 may be in a twisted wire state in which a plurality of CNT wires 10 are twisted together. By making the CNT wire 10 into the form of a stranded wire, the equivalent circle diameter and cross-sectional area of the CNT wire 10 can be adjusted as appropriate.

  The CNT wire 10 is formed from a single carbon nanotube aggregate (hereinafter also referred to as “CNT aggregate”) 11 composed of a plurality of CNTs 11a, 11a,. . Here, the CNT wire means a CNT wire having a CNT ratio of 90% by mass or more. In the calculation of the CNT ratio in the CNT wire, the mass of plating or dopant is excluded. In FIG. 1, the CNT wire 10 has a configuration in which a plurality of CNT aggregates 11 are twisted together. The longitudinal direction of the CNT aggregate 11 forms the longitudinal direction of the CNT wire 10. Therefore, the CNT aggregate 11 is linear. The plurality of CNT aggregates 11, 11,... In the CNT wire 10 are arranged so that the major axis directions thereof are substantially aligned. Therefore, the plurality of CNT aggregates 11, 11,... In the CNT wire 10 are oriented. Although the circle equivalent diameter of the CNT wire 10 which is a strand is not specifically limited, For example, they are 0.01 mm or more and 4.0 mm or less. Further, the CNT wire 10 may be configured by bundling a plurality of CNT aggregates 11. The equivalent circle diameter of one CNT wire 10 made of a stranded wire is not particularly limited, but is, for example, 0.1 mm or more and 15 mm or less. When a CNT wire is composed of a plurality of CNT wires, it is also called a CNT wire, and in this case, the upper limit of the cross-sectional area is not limited.

  The CNT wire 10 in FIG. 1 has a configuration in which a plurality of CNT aggregates 11 are twisted together. However, the present invention is not limited to this, and as shown in FIG. A state in which the directions are the same or substantially the same may be included. That is, the CNT wire 10 may include a bundle of a plurality of CNT aggregates 11 that are not twisted together.

  The CNT aggregate 11 is a bundle of CNTs 11a having a layer structure of one or more layers. The longitudinal direction of the CNT 11 a forms the longitudinal direction of the CNT aggregate 11. The plurality of CNTs 11a, 11a,... In the CNT aggregate 11 are arranged so that their major axis directions are substantially aligned. Therefore, the plurality of CNTs 11a, 11a,... In the CNT aggregate 11 are oriented. The equivalent circle diameter of the CNT aggregate 11 is, for example, 20 nm or more and 1000 nm or less, and more typically 20 nm or more and 80 nm or less. The width of the outermost layer of the CNT 11a is, for example, not less than 1.0 nm and not more than 5.0 nm.

  The CNTs 11a constituting the CNT aggregate 11 are cylindrical bodies having a single-layer structure or a multi-layer structure, and are called SWNT (single-walled nanotube) and MWNT (multi-walled nanotube), respectively. The CNT aggregate 11 may include a CNT having a layer structure of three or more layers, a CNT having a layer structure of a single layer structure, or a CNT having a layer structure of three or more layers or a single layer structure. You may form from CNT which has a layer structure.

  The CNT 11a having a two-layer structure has a three-dimensional network structure in which two cylindrical bodies having a hexagonal lattice network structure are arranged substantially coaxially, and is called DWNT (Double-walled nanotube). The hexagonal lattice, which is a structural unit, is a six-membered ring in which a carbon atom is arranged at the apex, and these are continuously bonded adjacent to another six-membered ring.

  For example, a CNT with a small number of layers such as a two-layer structure or a three-layer structure has a relatively higher conductivity than a CNT with a larger number of layers, and when subjected to doping treatment, the CNT has a two-layer structure or a three-layer structure. The doping effect in the CNT having a structure is the highest. Therefore, from the viewpoint of further improving the conductivity of the CNT wire 10, it is preferable to increase the proportion of CNTs having a two-layer structure or a three-layer structure. Specifically, the ratio of CNTs having a two-layer structure or a three-layer structure to the entire CNT is preferably 50% by number or more, and more preferably 75% by number or more. The ratio of CNTs having a two-layer structure or a three-layer structure is determined by observing and analyzing the cross section of the CNT aggregate 11 with a transmission electron microscope (TEM), and selecting a predetermined number of arbitrary CNTs within a range of 100, It can be calculated by measuring the number of layers of each CNT.

Next, the impregnation suppression part provided in the outer peripheral part of the CNT wire 10 will be described.
As described above, the CNT-coated electric wire 1 includes a plurality of impregnation suppression units 31, 31, 31, but it can also be understood that the CNT wire 10 includes a plurality of impregnation suppression units 31, 31, 31. That is, the CNT wire 10 has a plurality of impregnations that suppress the impregnation of the coating material constituting the insulating coating layer 21 that covers the CNT wire 10 on the outer peripheral portion of the CNT wire 10 over the entire circumferential direction. The suppression part 31,31, ... is provided.
In FIG. 1, the CNT wire 10 includes three impregnation suppression units 31, 31, 31, but is not limited thereto, and may include one impregnation suppression unit 31. In the present embodiment, the impregnation suppressing unit 31 is provided in an annular shape on the outer peripheral portion of the CNT wire 10 so as to cover the entire outer peripheral portion of the CNT wire 10.

  As shown in FIG. 1, the impregnation suppressing portion 31 is preferably formed at least at the end in the longitudinal direction of the CNT wire 10. Moreover, the impregnation suppression part 31 may be formed in the whole CNT wire 10 ranging from the longitudinal direction one end part of the CNT wire 10 to the other end part. Thereby, the insulation coating layer 21 provided in the longitudinal direction edge part of the CNT wire 10 can be removed easily. Moreover, when the impregnation suppression part 31 is formed in the whole CNT wire 10, while being able to remove the insulation coating layer 21 easily, there is no restriction | limiting of the site | part which removes the insulation coating layer 21, and externally The degree of freedom of electrical connection can be improved. Moreover, when the impregnation suppression part 31 is formed only in the location which performs the terminal process of the CNT wire 10, the insulating coating layer 21 of the CNT wire 10 can be easily removed and the insulating coating layer 21 is removed. The peeling of the insulating coating layer 21 at a place where no electrical contact is planned can be suppressed, and the safety of electrical connection with the outside can be improved.

  Moreover, the several impregnation suppression part 31,31, ... may be arrange | positioned intermittently in the longitudinal direction of the CNT wire 10. FIG. At this time, the plurality of impregnation suppressing portions 31, 31,... May be formed at the end portion in the longitudinal direction of the CNT wire 10 (FIG. 1) or from one end portion in the longitudinal direction of the CNT wire 10 to the other end portion. It may be formed over the entire CNT wire 10. Moreover, the some impregnation suppression part 31,31, ... may be arrange | positioned at equal intervals in a longitudinal direction, and the arrangement pitch of the some impregnation suppression part 31,31, ... is 0.5 m or more and 100 m, for example. It is as follows. Accordingly, the insulating coating layer 21 can be easily removed while reducing the material constituting the impregnation suppressing portion 31 as much as possible, and the restriction on the site where the insulating coating layer 21 is removed is reduced. The degree of freedom of connection can be improved.

  More specifically, the impregnation suppressing unit 31 has a connection structure that connects the CNTs 11 a located on the outermost surface layer of the CNT wire 10. This connection structure is bonded to one outer peripheral surface of the two CNTs 11a and 11a arranged adjacent to each other on the outermost surface layer of the CNT wire 10, and is also bonded to the other outer peripheral surface. That is, since the gap between the two adjacent CNTs 11a and 11a is filled with the connection structure, the coating material constituting the insulating coating layer 21 is difficult to pass between the two CNTs 11a and 11a. Can be prevented from entering the inside of the CNT wire 10.

  The impregnation suppressing unit 31 can be made of one or more materials selected from conductive paste, plating, and solder. Examples of the conductive paste include metal paste, conductive resin, and carbon paste. Examples of plating include electric field plating, electroless plating, hot dipping, and vapor phase plating. Examples of the solder include eutectic solder and lead-free solder.

  The conductive paste can be processed at a relatively low temperature, can be applied to a portion that is easily damaged by heat, and is preferably used from the viewpoint of exhibiting durability due to high thermal stress and mechanical adaptability. Plating is suitably used from the viewpoint that a thin layer can be formed as compared with solder, and the difference in diameter between the impregnation suppressing portion and other portions can be reduced. The solder is preferably used from the viewpoint that the impregnation suppressing portion 31 can be easily formed at a local position of the CNT wire 10.

In the present embodiment, the degree of unevenness on the outer peripheral surface of the impregnation suppressing unit 31 can be defined as follows. In the radial cross section of the CNT wire 10 where the impregnation suppressing part 31 is formed in an annular shape, the outer peripheral length of the impregnation suppressing part 31 is La, and the area of the part surrounded by La is S, where S and the area are When the circumferential length of the same circle is Lb, the average value of La / Lb measured at any plural places (for example, any five places) is 3.5 or less, preferably 1.3 or less. It is. If the average value of La / Lb is small, the degree of unevenness on the outer peripheral surface of the impregnation suppressing portion 31 is small, it is easy to remove the insulating coating layer 21, and it is assumed that the reliability of electrical connection with the outside is improved. In order to reduce the degree of unevenness on the outer peripheral surface of the impregnation suppressing portion 31, the average thickness of the impregnation suppressing portion 31 is preferably 3 μm or more, and more preferably 10 μm or more. When the average thickness of the impregnation suppressing portion is less than 3 μm, the uneven shape of the CNT wire is reflected on the unevenness of the outer peripheral surface of the impregnation suppressing portion 31, and the degree of unevenness increases.
Here, the average thickness of the impregnation suppressing portion is obtained by the following method. The radius of a circle having the same area as the area S of the region surrounded by the outer periphery of the impregnation suppressing portion 31 is R, and the radius of the circle having the same area as the cross-sectional area S ′ of the CNT wire 10 in the same cross section. Is R ′, and R—R ′ is obtained from any of five cross-sections, and an average value thereof is an average thickness.

  Next, the insulating coating layer 21 that covers the outer peripheral portion of the CNT wire 10 will be described.

  As a material of the insulating coating layer 21, a material used for an insulating coating layer of a covered electric wire using a metal as a core wire can be used, and examples thereof include a thermoplastic resin and a thermosetting resin. Examples of the thermoplastic resin include polytetrafluoroethylene (PTFE), polyethylene, polypropylene, polyacetal, polystyrene, polycarbonate, polyamide, polyvinyl chloride, polymethyl methacrylate, and polyurethane. Moreover, as a thermosetting resin, a polyimide, a phenol resin, etc. can be mentioned, for example. These may be used alone, or two or more kinds may be appropriately mixed and used.

  When the CNT-coated electric wire 1 is a high-voltage electric wire, the thermoplastic resin is preferably polyethylene or polyvinyl chloride, and particularly preferably crosslinked polyethylene or soft polyvinyl chloride.

  As shown in FIG. 1, the insulating coating layer 21 may be a single layer, or alternatively, two or more layers may be used. In addition, a thermosetting resin layer may be further provided on the insulating coating layer 21 as necessary. The thermosetting resin may contain a filler having a fiber shape or a particle shape.

  3, the CNT wire 10 is provided on the outer peripheral portion of the CNT wire 10 and is provided with a plurality of enamel-based resin coating portions 41, 41,. -You may further provide. In FIG. 3, the CNT wire 10 includes four enamel resin coating portions 41, 41, 41, 41, but is not limited thereto, and may include one enamel resin coating portion 41. In the present embodiment, the enamel-based resin coating portion 41 is annularly provided on the outer periphery of the CNT wire 10 so as to cover the entire outer periphery of the CNT wire 10.

  As shown in FIG. 3, the enamel-based resin coating portion 41 is preferably formed at least at the end in the longitudinal direction of the CNT wire 10. Further, the enamel-based resin coating portion 41 may be formed on the entire CNT wire 10 from one end in the longitudinal direction of the CNT wire 10 to the other end.

  The plurality of enamel resin coating portions 41, 41,... May be intermittently arranged in the longitudinal direction of the CNT wire 10. In this case, the plurality of enamel-based resin coating portions 41, 41,... Are alternately arranged with the plurality of impregnation suppression portions 31, 31,. Further, the plurality of enamel-based resin coating portions 41, 41,... May be formed at the end portion in the longitudinal direction of the CNT wire 10 (FIG. 3) or from one end portion in the longitudinal direction of the CNT wire 10 to the other end. It may be formed on the entire CNT wire 10 across the portion.

  The enamel-based resin coating portion 41 is made of one or more materials selected from, for example, polyurethane varnish, polyester varnish, heat-resistant solder varnish, amideimide varnish, polyesterimide varnish, self-lubricating varnish, and self-bonding varnish. Can do.

  In FIG. 3, the CNT wire 10 is covered with the enamel-based resin coating portion 41 and the insulating coating layer 21 in this order, but may be covered only with the enamel-based resin coating portion 41. That is, the CNT-coated electric wire 1 may include the CNT wire 1, one or a plurality of impregnation suppression units 31, and one or a plurality of enamel-based resin coating units 41.

[Method for producing carbon nanotube-coated electric wire]
Next, an example of a method for manufacturing the CNT-coated electric wire 1 according to this embodiment will be described with reference to FIG. First, CNT 11a is manufactured, and a CNT wire formed by bundling a plurality of CNT aggregates 11, 11,... From a single CNT aggregate 11 composed of a plurality of CNTs 11a, 11a,. 10 is produced (step S1).

  The CNT 11a can be produced by a technique such as a floating catalyst method (Patent No. 5819888) or a substrate method (Patent No. 5860603). The strands of the CNT wire 10 are, for example, dry spinning (Patent No. 5819888, Patent No. 5990202, Patent No. 5350635), wet spinning (Patent No. 5135620, Patent No. 5115771, Patent No. 5288359), liquid crystal spinning, etc. (Special Table 2014-530964) etc.

  At this time, the orientation of the CNT constituting the CNT wire 10, or the orientation of the CNT constituting the CNT aggregate, or the density of the CNT aggregate 11 or CNT 11a is, for example, spinning such as dry spinning, wet spinning, and liquid crystal spinning. It can be adjusted by appropriately selecting the method and the spinning conditions of the spinning method.

  Next, the impregnation suppression part 31 which suppresses the impregnation to the CNT wire 10 of the coating material which comprises the insulating coating layer 21 of the CNT wire 10 is formed in the outer peripheral part of the CNT wire 10 over the whole circumferential direction ( Step S2). As a method for forming the impregnation suppressing portion 31 with a conductive resin, for example, a conductive paste is placed on or applied to the outer peripheral portion of the CNT wire 10 so as to have a predetermined mass per predetermined length in the longitudinal direction of the CNT wire 10. The method of doing can be mentioned. As a method for forming the impregnation suppressing portion 31 by plating, for example, a method of forming copper plating of a predetermined thickness on the outer peripheral portion of the CNT wire 10 by electroplating can be mentioned. When the impregnation suppressing portion 31 is formed of solder, for example, a method of placing or applying the solder on the outer peripheral portion of the CNT wire 10 so as to have a predetermined mass per predetermined length with respect to the longitudinal direction of the CNT wire 10 may be mentioned. it can.

  After forming the impregnation suppressing part 31 and before forming the insulating coating layer 21 described later, one or a plurality of enamels arranged on the outer peripheral part of the CNT wire 10 at portions other than the impregnation suppressing part 31 as necessary. The system resin coating portion 41 may be formed. Examples of the method for forming the enamel-based resin coating portion 41 include a method in which an enamel resin is applied and baked. When the impregnation suppression part 31 is formed on the outer peripheral part of the CNT wire 10, in this step of forming the enamel resin coating part 41, the impregnation suppression part 31 impregnates the coating material constituting the enamel resin coating part 41. It is suppressed.

  Next, the insulating coating layer 21 is formed on the side opposite to the CNT wire 10 with respect to the impregnation suppressing portion 31 (step S3). At this time, the insulating coating layer 21 is formed over the entire longitudinal direction of the CNT wire 10 so as to cover the entire outer periphery of the CNT wire 10 including the outer peripheral surface of the impregnation suppressing portion 31. As a method of forming the insulating coating layer 21, a method of coating an insulating coating layer on an aluminum or copper core wire can be used. For example, a thermoplastic resin that is a raw material of the insulating coating layer 21 is melted to surround the CNT wire 10. And a method of coating around the CNT wire 10. As described above, when the impregnation suppressing portion 31 is formed on the outer peripheral portion of the CNT wire 10, the impregnation suppressing portion 31 suppresses the impregnation of the covering material constituting the insulating coating layer 21 in this step. By passing through the said process, the CNT covering electric wire 1 which concerns on this embodiment is manufactured.

  The CNT-coated electric wire 1 according to the present embodiment can be used as a general electric wire such as a wire harness, and a cable may be produced from a general electric wire using the CNT-coated electric wire 1.

[Process for processing carbon nanotube-coated wires]
When processing the CNT-coated electric wire 1 manufactured by the above-described manufacturing method, the insulating coating layer 21 formed on the side opposite to the CNT wire 10 with respect to the impregnation suppressing portion 31 is removed. For example, in the configuration in which the impregnation suppressing portion 31 and the insulating coating layer 21 are provided in this order on the outer peripheral portion of the CNT wire 10, the insulating coating layer 21 disposed on the radially outer side of the impregnation suppressing portion 31 is physically or Chemically exfoliate. As a method for chemically peeling, for example, a release agent that peels or coats the insulating coating by dipping or applying to the CNT-coated electric wire 1 can be used. In the above-described step of forming the insulating coating layer 21, since the coating material constituting the insulating coating layer 21 is suppressed by the impregnation suppression unit 31 as described above, the insulating coating layer 21 can be easily removed from the CNT wire 10. Can do.

  As described above, according to the present embodiment, one or a plurality of impregnation suppressing portions 31 are provided on the outer peripheral portion of the CNT wire 10 over the entire circumferential direction, and the insulating coating that covers the CNT wire 10 is provided. Since the impregnation of the covering material constituting the layer 21 into the CNT wire 10 is suppressed, when the insulating covering layer 21 is formed on the opposite side of the impregnation suppressing portion 31 from the CNT wire 10, the covering material of the insulating covering layer 21 is formed. Does not easily enter between CNTs or between CNT aggregates, and it is difficult for the coating material to remain. Therefore, the insulating coating layer 21 can be easily and sufficiently removed, and the reliability of electrical connection with the outside can be improved.

  Next, examples of the present invention will be described, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.

Example 1
First, a dry spinning method (Patent No. 5819888) for directly spinning CNTs produced by the floating catalyst method or a wet spinning method (Patent No. 5135620, Patent No. 5115771, Patent No. 5288359) and an equivalent circle diameter of 0.02 mm CNT aggregate was obtained. By combining these from 76 wires, a CNT wire having an equivalent circle diameter of 0.2 mm was obtained.

  Next, at the end in the longitudinal direction of the obtained CNT wire, the entire outer periphery of the CNT wire is coated with a conductive paste (product name “DW-250H-5”, silver filler-containing thermosetting paste manufactured by Toyobo Co., Ltd.). Thus, an impregnation suppressing part was formed. At this time, the conductive paste was placed on the outer periphery of the CNT wire so as to be 0.69 mg per cm in the longitudinal direction of the CNT wire.

(Example 2)
A CNT wire was produced in the same manner as in Example 1 except that the conductive paste was 0.33 mg per cm in the longitudinal direction of the CNT wire.

(Example 3)
A CNT wire was produced in the same manner as in Example 1 except that the conductive paste was 0.16 mg per cm in the longitudinal direction of the CNT wire.

Example 4
Plating (copper plating) was used in place of the conductive paste, and the entire outer peripheral portion of the CNT wire was coated with copper plating to form an impregnation suppression portion.
Plating was performed according to the following procedure. The CNT wire body was immersed in a plating solution composed of copper sulfate, formalin, and Rochelle salt, and electroless copper plated. Thereafter, the CNT wire was immersed in a plating solution composed of an aqueous solution of copper sulfate and sulfuric acid, and electroplated with 1A (ampere) to produce a CNT wire in which the CNT wire body was subjected to electroplating. At this time, the electrolysis time was adjusted so that a plating thickness of 20 μm was obtained by electric field plating, and copper plating was formed on the outer peripheral portion of the CNT wire. Otherwise, a CNT wire was produced in the same manner as in Example 1.

(Example 5)
A CNT wire was produced in the same manner as in Example 4 except that the plating thickness was 10 μm.

(Example 6)
A CNT wire was produced in the same manner as in Example 4 except that the plating thickness was 5 μm.

(Example 7)
Instead of the conductive paste, solder (Cametics, trade name “C-Solder”, tin-based solder alloy) was used, and the entire outer periphery of the CNT wire was coated with solder to form an impregnation suppression portion. At this time, the solder was placed on the outer periphery of the CNT wire so as to be 1.0 mg per cm in the longitudinal direction of the CNT wire. Otherwise, a CNT wire was produced in the same manner as in Example 1.

(Example 8)
A CNT wire was produced in the same manner as in Example 7 except that the solder was 0.48 mg per cm in the longitudinal direction of the CNT wire.

Example 9
A CNT wire was produced in the same manner as in Example 7 except that the solder was 0.16 mg per cm in the longitudinal direction of the CNT wire.

(Comparative Example 1)
A CNT wire was produced in the same manner as in Example 1 except that no impregnation suppressing portion was formed on the CNT wire.

(Comparative Example 2)
The outer peripheral portion of the CNT wire was coated with a conductive paste so that the maximum (100%) of the impregnation suppression portion formed over the entire circumference of the CNT wire was about 80%. That is, the conductive paste was not formed annularly on the outer periphery of the CNT wire, but was placed with a gap in the circumferential direction of the CNT wire. Otherwise, a CNT wire was produced in the same manner as in Example 1.

(Comparative Example 3)
The outer periphery of the CNT wire was coated with plating. At this time, the laser beam is irradiated from the axial direction of the CNT wire to the longitudinal end of the CNT wire under the laser conditions of YAG laser (wavelength: 1064 nm), output 100 W, frequency 200 Hz, duty ratio 10%, and 30 to 150 Roughening was performed for 2 seconds, and the roughened portion of the CNT wire was impregnated with plating. As a result, there were CNTs (or CNT aggregates) that were not coated with plating at the outer periphery of the CNT wire. Otherwise, a CNT wire was produced in the same manner as in Example 1.

  Next, the following measurements and evaluations were performed on the CNT wire produced as described above.

(A) Concavities and convexities on the outer periphery of the CNT wire The longitudinal ends of the CNT wire are cut at 5 places with a uniform width and a plane perpendicular to the longitudinal direction to obtain a cross section, and the impregnation suppressing portion in each cross section of the CNT wire The outer peripheral length La was determined. Subsequently, the cross-sectional area S of each said cross section was calculated | required, and the circumference length Lb of the circle | round | yen which is the same area as the calculated | required cross-sectional area was calculated. La / Lb was calculated by dividing the outer circumferential length La of each cross section by the circumferential length Lb, and the average value of La / Lb measured at any five locations was used as the unevenness index.

(B) Average thickness of impregnation suppression part Using the same cross section as (a), the radius R of a circle having the same area as the area S of the region surrounded by the outer periphery of the impregnation suppression part was determined. Subsequently, a radius R ′ of a circle having the same area as the area S ′ of the CNT wire portion was obtained. RR ′ was calculated, and the average value of RR ′ obtained at any five locations was defined as the average thickness of the impregnation suppression portion.

(C) Connection reliability after removal of coating CNT wire is impregnated with polyurethane resin (trade name “TPU5100”, manufactured by Tohoku Paint Co., Ltd.) and repeated ten times to form an insulating coating layer on the CNT wire. did. Thereafter, the end of the CNT wire in the longitudinal direction was impregnated with a release agent (trade name “Solcoat (registered trademark)” manufactured by Meiwa Chemical Industry Co., Ltd.) to perform a coating removal treatment. And the part which carried out the coating removal process of the CNT wire and the copper terminal were connected with the solder, and the connection resistance of the CNT wire and the copper terminal was measured by the four-terminal method. Very good when connection resistance is less than 5 mΩ “◎”, “◯” when 5 mΩ or more and 20 mΩ or less, “Good” when 20 mΩ or more and 100 Ω or less, “△”, poor when larger than 100 Ω It was set as “x”.

  The results of the above measurements and evaluations of the CNT-coated wires are shown in Table 1 below.

  As shown in Table 1, in Example 1, La / Lb was 1.3, the connection resistance was 8 mΩ, and the connection reliability after removal of the coating was very good. In Example 2, La / Lb was 2.0 and the connection resistance was 11 mΩ, and the connection reliability after removal of the coating was good. Also in Example 3, La / Lb was 3.5 and the connection resistance was 16 mΩ, and the connection reliability after removal of the coating was good.

  In Example 4, La / Lb was 1.3, the connection resistance was 5 mΩ, and the connection reliability after removal of the coating was very good. In Example 5, La / Lb was 2.0 and the connection resistance was 7 mΩ, and the connection reliability after removal of the coating was good. In Example 6, La / Lb was 3.5 and the connection resistance was 10 mΩ, and the connection reliability after removal of the coating was good.

  In Example 7, La / Lb was 1.3, the connection resistance was 6 mΩ, and the connection reliability after removal of the coating was very good. In Example 8, La / Lb was 2.0 and the connection resistance was 8 mΩ, and the connection reliability after removal of the coating was good. In Example 9, La / Lb was 3.5 and the connection resistance was 12 mΩ, and the connection reliability after removal of the coating was good.

  On the other hand, in Comparative Example 1, although La / Lb is 2.5, since the impregnation suppression portion is not formed on the outer peripheral portion of the CNT wire, the coating material constituting the insulating coating layer is impregnated into the CNT wire, The material could not be removed sufficiently, the connection resistance was 1700 mΩ, and the connection reliability after removal of the coating was inferior.

  In Comparative Example 2, although La / Lb is 1.4, since the impregnation suppressing portion is formed so as to be about 80% with respect to the entire circumference of the CNT wire, the impregnation suppressing portion is not formed in the entire circumferential direction. First, the coating material impregnates the CNT wire from the part where the impregnation suppression part is not formed, and the impregnated coating material elutes at the time of coating removal, and reattachment occurs on the surface of the CNT wire, and the coating material is sufficiently removed. The connection resistance was 265 mΩ, and the connection reliability after removal of the coating was inferior.

  In Comparative Example 3, although La / Lb was 1.6, there was CNT that was not connected by the plating connection structure in the outer peripheral portion of the CNT wire after the roughening treatment. The CNT wire is impregnated into the coating material from the part where the connection structure is not formed, and the impregnated coating material elutes when the coating is removed. It could not be removed sufficiently, and the connection resistance was 374 mΩ, and the connection reliability after removal of the coating was inferior.

1 Carbon nanotube coated electric wire (CNT coated electric wire)
10 Carbon nanotube wire (CNT wire)
11 Carbon nanotube aggregate (CNT aggregate)
11a Carbon nanotube (CNT)
21 Insulation coating layer 31 Impregnation suppression part 41 Enamel resin coating part

Claims (9)

A carbon nanotube wire formed by bundling a plurality of the carbon nanotube aggregates from a single carbon nanotube aggregate composed of a plurality of carbon nanotubes,
One or a plurality of impregnation suppression portions that suppress impregnation of the coating material constituting the insulating coating layer that covers the carbon nanotube wire over the entire circumference in the outer peripheral portion of the carbon nanotube wire. A carbon nanotube wire characterized by comprising:   2. The carbon nanotube wire according to claim 1, wherein the impregnation suppressing part has a connection structure that connects the carbon nanotubes located in the outermost layer of the carbon nanotube wire.   The carbon nanotube wire according to claim 1 or 2, wherein the plurality of impregnation suppressing portions are intermittently disposed in a longitudinal direction of the carbon nanotube wire.   The carbon nanotube wire according to any one of claims 1 to 3, wherein the one or more impregnation suppressing portions are formed at least at a longitudinal end portion of the carbon nanotube wire.   The carbon nanotube wire according to any one of claims 1 to 4, wherein the impregnation suppressing portion is made of any material selected from conductive paste, plating, and solder.   The carbon according to any one of claims 1 to 5, further comprising one or a plurality of enamel-based resin coating portions provided on an outer peripheral portion of the carbon nanotube wire and disposed in a portion other than the impregnation suppressing portion. Nanotube wire. Carbon nanotube wire,
An insulating coating layer covering the carbon nanotube wire;
One or a plurality of impregnations that suppress impregnation of the coating material constituting the insulating coating layer into the carbon nanotube wire between the carbon nanotube wire and the insulating coating layer over the entire circumferential direction of the carbon nanotube wire. A suppression unit;
A carbon nanotube-coated electric wire comprising: One or a plurality of impregnation suppression portions that suppress impregnation of the coating material constituting the insulating coating layer of the carbon nanotube wire into the carbon nanotube wire is formed on the outer circumferential portion of the carbon nanotube wire. Process,
Forming the insulating coating layer on the opposite side of the carbon nanotube wire with respect to the impregnation suppressing portion;
A method for producing a carbon nanotube-coated electric wire, comprising: A carbon nanotube wire, an insulating coating layer that covers the carbon nanotube wire, and a coating that forms the insulating coating layer across the entire circumferential direction of the carbon nanotube wire between the carbon nanotube wire and the insulating coating layer A method of processing a carbon nanotube-covered electric wire comprising one or a plurality of impregnation suppression portions that suppress impregnation of the material into the carbon nanotube wire, and formed on the opposite side of the carbon nanotube wire relative to the impregnation suppression portion A method for processing a carbon nanotube-covered electric wire, comprising removing the insulating coating layer formed.