JP2019178466A - Method for producing carbon nanotube wire rod and carbon nanotube wire rod - Google Patents

Abstract

To provide a method for producing a carbon nanotube capable of highly orienting a plurality of carbon nanotube aggregates to enhance mechanical strength of the carbon nanotube wire rod.SOLUTION: In a method for producing a carbon nanotube wire rod, a dispersion containing a plurality of CNT is discharged from a discharging part 2 such as a syringe into a coagulation bath 1 filled with a coagulation liquid to prepare a CNT raw yarn (A), and then the CNT raw yarn (A) is subjected to stretching treatment in the coagulation bath 1 to prepare a CNT raw yarn (B).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a carbon nanotube wire composed of a plurality of carbon nanotubes, and a carbon nanotube wire that is produced by the method and in which a plurality of carbon nanotube aggregates are oriented.

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

  For example, a carbon nanotube is a three-dimensional network structure composed of a single layer of a cylindrical body having a hexagonal lattice network structure or a multilayer arranged substantially coaxially, and is lightweight, conductive, thermally conductive. Excellent properties such as conductivity and mechanical strength. However, it is not easy to turn carbon nanotubes into a wire, and no technology that uses carbon nanotubes as a wire has been proposed.

  As a method for producing a carbon nanotube wire, for example, a dispersion containing a carbon nanotube and a thickener selected from the group consisting of carboxymethylcellulose and polyvinylpyrrolidone is discharged into a coagulation bath, spun, stretched, and obtained. A method of removing the thickener by treating the drawn yarn with a solvent in which the thickener can be dissolved is disclosed (Patent Document 1).

JP 2010-168679 A

  In the above-mentioned conventional technique, a spinning raw material is obtained by wet spinning by discharging a dispersion into a coagulation bath by an extrusion spinning method, and the spinning raw yarn is drawn by a drawing machine while applying hot air with a dryer. By doing so, a carbon nanotube wire is obtained. The above prior art discloses that the draw ratio is about 1.1 to 3 times. When the spinning raw yarn is taken out from the coagulation liquid and then drawn while heating, the solidification process of CNT is almost completed. Even if a force is applied in the linear direction, the arrangement of the CNTs hardly changes even when a force is applied in the linear direction, and if a force is applied more than necessary, the CNTs tend to break starting from a place where the interaction and entanglement between the CNTs is weak. For this reason, it is difficult to increase the draw ratio in the above prior art, the orientation of the plurality of carbon nanotube aggregates constituting the carbon nanotube wire becomes insufficient, and there is a limit to improving the mechanical strength of the carbon nanotube wire. is there. In addition, even if the carbon nanotube wire after the spinning process is stretched while applying heat, the spinning yarn is slightly stretched, and the orientation of the plurality of carbon nanotube aggregates constituting the carbon nanotube wire is improved. It is difficult.

  An object of the present invention is to provide a carbon nanotube wire manufacturing method and a carbon nanotube wire capable of highly orienting a plurality of carbon nanotube aggregates and increasing the mechanical strength of the carbon nanotube wire.

  In order to achieve the above object, a method for producing a carbon nanotube wire of the present invention comprises a step of producing a carbon nanotube yarn (A) by discharging a dispersion containing a plurality of carbon nanotubes into a coagulation liquid, The carbon nanotube yarn (A) is drawn in the coagulating liquid to produce the carbon nanotube yarn (B).

  The conveyance speed V2 of the second conveyance unit disposed on the downstream side in the drawing direction of the carbon nanotube raw yarn (A) is set to be larger than the conveyance speed V1 of the first conveyance unit arranged on the upstream side in the drawing direction. In addition, it is preferable that the carbon nanotube raw yarn (A) is stretched while being sandwiched by both the first transport unit and the second transport unit.

  The first transport unit is a first pair of sandwiching rollers disposed in the coagulating liquid, and the second transport unit is a second pair of sandwiching rollers disposed in the coagulating liquid, It is preferable that V2 / V1, which is a ratio of the transport speed V2 of the second pair of sandwiching rollers to the transport speed V1 of the first pair of sandwiching rollers, is 3 or more and 10 or less.

  In order to achieve the above object, a carbon nanotube wire of the present invention is a carbon nanotube wire formed by bundling a plurality of carbon nanotube aggregates composed of a plurality of carbon nanotubes, and a plurality of the carbon nanotube wires The azimuth angle half-value width Δθ in the azimuth plot by small-angle X-ray scattering indicating the orientation of the aggregate is 25 ° or more and less than 50 °.

  In the cross section of the carbon nanotube wire, a plurality of the carbon nanotube wire constituting the outer peripheral portion of the carbon nanotube wire with respect to the FWHM Δθin of the azimuth angle indicating the orientation of the plurality of carbon nanotube aggregates constituting the inside of the carbon nanotube wire It is preferable that Δθout / Δθin, which is a ratio of the half width Δθout of the azimuth angle indicating the orientation of the carbon nanotube aggregate, is larger than 0.85.

  According to the present invention, a carbon nanotube yarn (A) is formed by discharging a dispersion containing a plurality of carbon nanotubes into a coagulation solution, and the carbon nanotube yarn (A) is drawn in the coagulation solution. Thus, the carbon nanotube yarn (B) is formed, so that a plurality of carbon nanotube aggregates constituting the carbon nanotube yarn (B) can be highly oriented, and the carbon nanotube wire obtained from the CNT yarn (B) Mechanical strength can be increased.

It is a flowchart which shows an example of the manufacturing method of the carbon nanotube wire which concerns on embodiment of this invention. It is a figure explaining the process of extending | stretching a carbon nanotube raw material yarn (A) in the coagulating liquid in the manufacturing method of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a flowchart showing an example of a carbon nanotube wire manufacturing method according to this embodiment. In the present embodiment, carbon nanotubes are spun by a wet spinning method as a method for producing a carbon nanotube wire.
As shown in FIG. 1, first, carbon nanotubes (hereinafter referred to as “CNT”) prepared by a floating catalyst method (Patent No. 5819888) and a substrate method (Patent No. 5990603) are prepared, and a plurality of CNTs are prepared. And a solvent are mixed to prepare a dispersion containing a plurality of CNTs (step S1). Examples of the solvent for the dispersion include organic solvents such as toluene, N-methylpyrrolidone (NMP), sodium dodecyl sulfonate, dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), and methyl isobutyl ketone (MIBK). An aqueous solution containing a surfactant is used. As the surfactant, an anionic surfactant such as alkylbenzene sulfonate and alkyl sulfate, and a cationic surfactant such as tetraalkylammonium halide can be used. The carbon nanotube content in the dispersion is, for example, 0.05 to 20% by mass.

  The dispersion may contain a thickener for increasing the viscosity. As the thickener, for example, carboxymethylcellulose (CMC), polyvinylpyrrolidone (PVP), glycerin, and ethylene glycol are used. Content of the thickener in a dispersion liquid is 0.05-5 mass%, for example.

  Next, as shown in FIG. 2, the dispersion containing a plurality of CNTs is discharged from a discharge unit 2 such as a syringe into a coagulation bath 1 filled with a coagulation liquid, and a carbon nanotube raw yarn (hereinafter, “ (Also referred to as “CNT yarn”) (A) is produced (step S2). When the dispersion liquid is discharged into the coagulation liquid, it comes into contact with the coagulation liquid, thereby forming a plurality of CNT aggregates in a linear shape. At this time, the CNT raw yarn (A) may have a configuration in which a plurality of CNT aggregates are twisted together, and the longitudinal direction of the plurality of CNT aggregates and the longitudinal direction of the CNT raw yarn (A) are the same or substantially the same. May be included in the same state. That is, the CNT raw yarn (A) may include a bundle in which a plurality of CNT aggregates are not twisted together.

  As the coagulation liquid, for example, those having different affinity with the dispersion solvent such as NMP, N, N-dimethylacetamide (DMA), DMF, water, methanol, ethanol, propanol and the like are appropriately selected and used.

  Next, as shown in FIG. 2, the CNT yarn (A) is drawn in the coagulation bath 1 to produce a carbon nanotube yarn (hereinafter also referred to as “CNT yarn”) (B) (step S3). . For example, this stretching process is performed continuously in the coagulating liquid after the dispersion liquid is discharged into the coagulating liquid in the above-described discharging step.

  As a method of stretching the CNT raw yarn (A), for example, in the coagulation bath 1, the first conveyance unit 3 is disposed upstream in the stretching direction X of the CNT raw yarn (A), and the first conveying unit 3 is disposed downstream in the stretching direction X. The 2nd conveyance part 4 is arrange | positioned, respectively. And the conveyance speed V2 of the 2nd conveyance part arrange | positioned downstream with respect to the extending | stretching direction X of CNT original yarn (A) is compared with the conveyance speed V1 of the 1st conveyance part 3 arrange | positioned upstream with respect to the said extending | stretching direction X. The CNT raw yarn (A) is sandwiched between both the first transport unit 3 and the second transport unit 4 and stretched. Giving tensile stress along the longitudinal direction to the CNT yarn (A) in the coagulation bath 1 by making the conveyance speed V2 of the second conveyance unit 4 larger than the conveyance speed V1 of the first conveyance unit 3. Can do.

Here, in the above-described prior art, it is difficult to increase the draw ratio because of the stretching in a state where the solidified CNTs are strongly aggregated. On the other hand, in the present invention, the CNT aggregates are stretched in the coagulating liquid, and the CNT aggregates are not separated from each other through the dispersion medium even when a force is applied in the linear direction in a state surrounded by the dispersion medium. Since the arrangement can be changed, a high stretch ratio can be obtained without breaking as compared with the prior art.
Also, in the solidification treatment of the CNT wire, since the dispersion liquid oozes out from the outer periphery of the CNT wire and solidification proceeds, the density of the plurality of CNT aggregates constituting the inside of the CNT wire is determined by the outer periphery of the CNT wire. Tends to be smaller than the density of the plurality of CNT aggregates constituting the CNT. Therefore, in the case of the conventional method in which the stretching process is performed after the solidification process, in the CNT wire that has been solidified by the solidification process, the density of a plurality of CNT aggregates constituting the inside of the CNT wire constitutes the outer peripheral part of the CNT wire. It is assumed that the density is smaller than the density of the plurality of CNT aggregates. In addition, when the CNT wire having the difference in density is stretched while being heated, it is difficult to receive the force from the adjacent CNT aggregate within the CNT wire having a small density of the CNT aggregate. The orientation is lower than that of the outer peripheral portion having a large density.

  On the other hand, when the CNT yarn (A) is stretched in the coagulating liquid as in the present embodiment, the CNTs are gradually solidified from the outer peripheral portion of the CNT yarn (A) toward the inside. Since the raw yarn (A) is drawn, a decrease in density of the plurality of CNT aggregates constituting the inside of the CNT raw yarn (A) is suppressed, and a plurality of CNT aggregates constituting the inside of the CNT raw yarn (A) And the density of the plurality of CNT aggregates constituting the outer peripheral portion of the CNT raw yarn (A) become small. Further, since the CNT raw yarn (A) is not heated during the stretching process, the progress of solidification of the outer peripheral portion can be suppressed. Therefore, in the drawing process, the long axis direction of the plurality of CNT aggregates constituting the outer peripheral portion of the CNT raw yarn (A), and the long axis direction of the plurality of CNT aggregates constituting the inside of the CNT raw yarn (A) Are easily aligned, and solidification of the plurality of CNT aggregates is completed in a state where the major axis directions of the plurality of CNT aggregates in the entire CNT raw yarn (A) are substantially aligned. Thereby, the orientation of the whole several CNT aggregate | assembly which comprises CNT original yarn (B) improves.

  Said 1st conveyance part 3 is a 1st pair of clamping rollers 3a and 3b arrange | positioned in coagulating liquids, such as coagulation bath 1, for example, and the 2nd conveyance part 4 is coagulating liquids, such as coagulation bath 1, for example A second pair of sandwiching rollers 4a and 4b disposed therein. The first pair of sandwiching rollers 3a and 3b are configured to be rotatable in the coagulating liquid at a predetermined rotational speed, and the transport speed of the CNT raw yarn (A) that is the transported body is set based on the predetermined rotational speed. Or it is adjusted. Similarly, the second pair of sandwiching rollers 4a and 4b are configured to be rotatable at a predetermined rotation speed, and the conveyance speed of the CNT raw yarn (A) as a conveyed body is set or adjusted based on the predetermined rotation speed. The

  When the transport speed of the first pair of sandwiching rollers 3a and 3b is V1, and the transport speed of the second pair of sandwiching rollers 4a and 4b is V2, it corresponds to the transport speed V1 of the first pair of sandwiching rollers 3a and 3b. V2 / V1, which is the ratio of the conveyance speed V2 of the second pair of sandwiching rollers 4a and 4b, is, for example, 3 or more and 10 or less, preferably 4 or more and 10 or less, more preferably 6 or more and 10 or less. As a result, the tensile stress applied to the CNT yarn (A) is further increased, and the density of the plurality of CNT aggregates constituting the inside of the CNT yarn (A) and the outer peripheral portion of the CNT yarn (A) are reduced. The difference from the density of the plurality of CNT aggregates to be formed can be further reduced, and the orientation of the plurality of CNT aggregates constituting the CNT raw yarn (B) is further improved.

  After passing through the above steps, the CNT raw yarn (B) is dried and heated as necessary to produce the CNT wire according to this embodiment.

[Configuration of CNT wire]
The CNT wire manufactured by the above manufacturing method is formed by bundling a plurality of CNT aggregates composed of a plurality of CNTs. 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. The longitudinal direction of the CNT aggregate forms the longitudinal direction of the CNT wire. Therefore, the CNT aggregate is linear. A plurality of CNT aggregates in the CNT wire are arranged so that the major axis directions thereof are substantially aligned. Therefore, the plurality of CNT aggregates in the CNT wire are oriented. Although the circle equivalent diameter of the CNT wire which is a strand is not specifically limited, For example, it is 0.01 mm or more and 1.0 mm or less. In addition, the CNT wire may be configured by bundling a plurality of CNT aggregates. The equivalent circle diameter of one CNT wire made of a stranded wire is not particularly limited, but is, for example, 0.05 mm or more and 5 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 may have a configuration in which a plurality of CNT aggregates are twisted together, or may include a state in which the longitudinal direction of the CNT aggregates and the longitudinal direction of the CNT wires are the same or substantially the same. That is, the CNT wire may include a bundle in which a plurality of CNT aggregates are not twisted together.

  A CNT aggregate is a bundle of CNTs having a layer structure of one or more layers. The longitudinal direction of CNT forms the longitudinal direction of the CNT aggregate. The plurality of CNTs in the CNT aggregate are arranged so that their major axis directions are substantially aligned. Therefore, the plurality of CNTs in the CNT aggregate are oriented. The equivalent circle diameter of the CNT aggregate 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 dimension of the outermost layer of CNT is 1.0 nm or more and 20 nm or less, for example.

  The CNTs constituting the CNT aggregate 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 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 layer of a single layer structure You may form from CNT which has a structure.

  A CNT 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.

  Next, the orientation of CNT and CNT aggregate in the CNT wire will be described.

  Small angle X-ray scattering (SAXS) is suitable for evaluating a structure having a size of several nanometers to several tens of nanometers. For example, the orientation of a CNT aggregate having an outer diameter of several tens of nanometers can be evaluated by analyzing information of an X-ray scattering image by the following method using SAXS. Since a plurality of CNT aggregates have good orientation, mechanical strength such as tensile strength can be further increased as compared with conventional CNT wires. The orientation refers to the angle difference between the internal CNT and the CNT aggregate vector with respect to the vector V in the longitudinal direction of the stranded wire produced by twisting together the CNTs.

  In the present embodiment, the mechanical property of the CNT wire is obtained by obtaining an orientation greater than a certain value indicated by the half-value width Δθ of the azimuth angle in the azimuth plot of small angle X-ray scattering (SAXS) indicating the orientation of a plurality of CNT aggregates From the viewpoint of increasing the strength, the half width Δθ of the azimuth angle is 25 ° or more and less than 50 °, and preferably 29 ° or more and 45 ° or less.

  In the present embodiment, in the cross section of the CNT wire, a plurality of CNTs constituting the outer peripheral portion of the CNT wire with respect to the half-value width Δθin of the azimuth angle indicating the orientation of the plurality of CNT aggregates constituting the inside of the CNT wire. Δθout / Δθin, which is the ratio of the FWHM Δθout of the azimuth angle indicating the orientation of the aggregate, is greater than 0.85, and preferably 0.89 or more. The inside of the CNT wire refers to a region inside the half of the equivalent circle radius from the center in the cross section in the width direction, and the outer peripheral portion of the CNT wire is a portion other than the inside of the CNT wire, An area outside the half of the equivalent circle radius from the inner center. When Δθout / Δθin is 0.85 or more, the difference between the orientation of the CNT aggregate in the CNT wire and the orientation of the plurality of CNT aggregates in the outer peripheral portion becomes small, and the tensile strength of the CNT wire, etc. Improved mechanical properties.

  The CNT wire may be provided with an insulating coating layer that covers the outer periphery thereof. In that case, the CNT wire and the insulating coating layer constitute a CNT-coated electric wire.

  As a material of the insulating coating layer, a material used for an insulating coating layer of a coated 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, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ether ketone, polycarbonate, polyamide, polyvinyl chloride, polymethyl methacrylate, and polyurethane. Etc. 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-covered electric wire is a high-voltage electric wire, the thermoplastic resin is preferably polyethylene or polyvinyl chloride, and particularly preferably crosslinked polyethylene or soft polyvinyl chloride.

  The insulating coating layer may be a single layer, or alternatively, two or more layers. Further, if necessary, a layer of a thermosetting resin may be further provided on the insulating coating layer. The thermosetting resin may contain a filler having a fiber shape or a particle shape.

  The insulating coating layer is formed over the entire length of the CNT wire so as to cover the entire outer periphery of the CNT wire, for example. As a method of forming the insulation coating layer, a method of coating the insulation coating layer on an aluminum or copper core wire can be used. For example, a thermoplastic resin that is a raw material of the insulation coating layer is melted and extruded around the CNT wire. Examples thereof include a coating method and a method of coating around a CNT wire.

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

  As described above, according to this embodiment, a dispersion containing a plurality of CNTs is discharged into the coagulation liquid to form the CNT original yarn (A), and the CNT original yarn (A) is stretched in the coagulation liquid. Since the CNT raw yarn (B) is formed by processing, a plurality of CNT aggregates constituting the CNT raw yarn (B) can be highly oriented, and the mechanical properties of the CNT wire obtained from the CNT raw yarn (B) Strength can be increased.

  Further, the CNT wire manufactured by the above manufacturing method is formed by bundling a plurality of CNT aggregates composed of a plurality of CNTs, and azimuth by small angle X-ray scattering indicating the orientation of the plurality of CNT aggregates. Since the half width Δθ of the azimuth angle in the plot is 25 ° or more and less than 50 °, the orientation of the plurality of CNT aggregates constituting the CNT wire is good, and a CNT wire with high mechanical strength can be provided. .

  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, CNTs were prepared by a floating catalyst method, an aqueous solution containing 0.5% by mass of each of CNTs and sodium dodecyl sulfonate was prepared, and subjected to ultrasonic treatment for 30 minutes to obtain a dispersion.

  Next, ethanol was prepared as a coagulation liquid, and the dispersion containing a plurality of CNTs was discharged from a syringe into a coagulation bath to form a CNT yarn (A). Next, the transport speed V1 of the first pair of sandwiching rollers, the transport speed V2 and V2 / V1 of the second pair of sandwiching rollers are set to the values shown in Table 1, and the CNT raw yarn (A) is set. The first pair of sandwiching rollers and the second pair of sandwiching rollers were sandwiched and conveyed in this order, and the CNT raw yarn (A) was drawn in a coagulating liquid to produce the CNT raw yarn (B). Thereafter, the CNT raw yarn (B) was dried to obtain a CNT wire having an equivalent circle diameter of 50 μm to 300 μm.

(Example 2)
A CNT wire was produced in the same manner as in Example 1 except that the conveying speeds V2 and V2 / V1 of the second pair of sandwiching rollers were changed.

(Example 3)
A CNT wire was produced in the same manner as in Example 1 except that the conveying speeds V2 and V2 / V1 of the second pair of sandwiching rollers were changed.

Example 4
A CNT wire was produced in the same manner as in Example 1 except that the conveying speeds V2 and V2 / V1 of the second pair of sandwiching rollers were changed.

(Example 5)
A CNT wire was produced in the same manner as in Example 3 except that the conveyance speed V1 of the first pair of clamping rollers and the conveyance speed V2 of the second pair of clamping rollers were changed.

(Example 6)
A CNT wire was produced in the same manner as in Example 4 except that the conveyance speed V1 of the first pair of clamping rollers and the conveyance speed V2 of the second pair of clamping rollers were changed.

(Comparative Example 1)
A CNT wire was produced in the same manner as in Example 1 except that the conveying speeds V2 and V2 / V1 of the second pair of sandwiching rollers were changed.

(Comparative Example 2)
According to the manufacturing method described in JP 2010-168679 A, a stretching process was performed while heating at a stretching ratio of 1.2 to prepare a CNT wire.

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

(A) Orientation degree of CNT aggregate Using a focused ion beam (FIB), it was thinly sliced to a thickness of 50 μm in the cross-sectional direction of the CNT wire. Using a small-angle X-ray scattering device, X-rays are incident in the direction perpendicular to the surface of the slice piece, and the azimuth plot (azimuth angle) of the obtained scattering peak is fitted with a Gaussian function or Lorentz function to obtain an azimuth angle. The half-value width Δθ of was obtained.

(B) Orientation inside / outside ratio Using micro-beam small-angle X-rays, X-rays each having a beam size reduced to 10 μm are incident in a direction perpendicular to the surface of the slice piece cut out from the CNT wire in the same manner as above In the same manner as described above, the half-value width Δθ of the azimuth angle was obtained. The half width of the azimuth angle when X-rays were incident on the outer peripheral portion and the inside of the CNT wire on the above surface was evaluated as Δθout and Δθin, respectively, and Δθout / Δθin was evaluated as the orientation internal / external ratio α.

(C) Tensile strength A tensile tester was used to measure the tensile strength in the longitudinal direction of the CNT wire. Very good when the tensile strength at break is greater than 600 MPa “◎”, good when it is greater than 500 MPa and less than or equal to 600 MPa, “good”, and generally better when greater than 400 MPa and less than or equal to 500 MPa “Δ”, 400 MPa The case where it was below was set as defect "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, V2 / V1, which is the ratio of the conveyance speed V2 of the second pair of nip rollers to the conveyance speed V1 of the first pair of nip rollers, is 10, and the degree of orientation is 10. It was 29 °, the orientation ratio was 0.95, the tensile strength was 714 MPa, and the mechanical strength was very good.

  In Example 2, V2 / V1 was 6, the degree of orientation was 37 °, the orientation ratio was 0.93, the tensile strength was 625 MPa, and the mechanical strength was very good.

  In Example 3, V2 / V1 was 4, the degree of orientation was 44 °, the orientation ratio was 0.89, the tensile strength was 511 MPa, and the mechanical strength was good.

  In Example 4, V2 / V1 was 3, the degree of orientation was 48 °, the orientation ratio was 0.91, the tensile strength was 402 MPa, and the mechanical strength was generally good.

  In Example 5, V1 is 0.4 m / min, V2 is 1.6 m / min, V2 / V1 is 4, the degree of orientation is 42 °, the orientation ratio is 0.94, and the tensile strength is 523 MPa. The mechanical strength was good.

  In Example 6, V1 was 0.4 m / min, V2 was 1.2 m / min, V2 / V1 was 3, the degree of orientation was 47 °, the orientation ratio was 0.88, and the tensile strength was 419 MPa. The mechanical strength was generally good.

  On the other hand, in Comparative Example 1, the transport speed V1 of the first pair of sandwiching rollers is the same as that of Embodiment 1, but the transport speed V2 of the second pair of sandwiching rollers is smaller than that of Embodiment 1, and V2 / V1 is 1. The degree of orientation was 50 °, the orientation ratio was 0.83, the tensile strength was 376 MPa, and the mechanical strength was poor.

  In Comparative Example 2, when the stretching treatment was performed while heating at a stretching ratio of 1.2, the degree of orientation was 52 °, the orientation ratio was 0.85, the tensile strength was 345 MPa, and the mechanical strength was Was inferior.

DESCRIPTION OF SYMBOLS 1 Coagulation bath 2 Discharge part 3 1st conveyance part 3a, 3a 1st pair of clamping roller 4 2nd conveyance part 4a, 4a 2nd pair of clamping roller X Stretching direction (A) CNT original yarn (B) CNT raw material yarn

Claims (5)

A step of producing a carbon nanotube yarn (A) by discharging a dispersion containing a plurality of carbon nanotubes into a coagulating liquid;
A method for producing a carbon nanotube wire, wherein the carbon nanotube yarn (A) is drawn in the coagulating liquid to produce the carbon nanotube yarn (B).   The conveyance speed V2 of the second conveyance unit disposed on the downstream side in the drawing direction of the carbon nanotube raw yarn (A) is set to be larger than the conveyance speed V1 of the first conveyance unit arranged on the upstream side in the drawing direction. The carbon nanotube wire manufacturing method according to claim 1, wherein the carbon nanotube raw material (A) is stretched while being sandwiched between both the first transport unit and the second transport unit. The first transport unit is a first pair of sandwiching rollers disposed in the coagulating liquid, and the second transport unit is a second pair of sandwiching rollers disposed in the coagulating liquid,
The carbon nanotube wire according to claim 2, wherein V2 / V1, which is a ratio of the conveyance speed V2 of the second pair of clamping rollers to the conveyance speed V1 of the first pair of clamping rollers, is 3 or more and 10 or less. Manufacturing method. A carbon nanotube wire formed by bundling a plurality of carbon nanotube aggregates composed of a plurality of carbon nanotubes,
A carbon nanotube wire characterized by having a azimuth angle half-value width Δθ of 25 ° or more and less than 50 ° in an azimuth plot by small-angle X-ray scattering indicating the orientation of a plurality of carbon nanotube aggregates. In the cross section of the carbon nanotube wire, a plurality of the carbon nanotube wire constituting the outer peripheral portion of the carbon nanotube wire with respect to the half width Δθin of the azimuth angle indicating the orientation of the plurality of carbon nanotube aggregates constituting the inside of the carbon nanotube wire The carbon nanotube wire according to claim 4, wherein Δθout / Δθin, which is a ratio of half-value width Δθout of the azimuth angle indicating the orientation of the carbon nanotube aggregate, is larger than 0.85.