JP2020164382A - Carbon nanotube wire - Google Patents
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本発明は、カーボンナノチューブ線材に関し、特に、平均長さが１５μｍ以上である複数のカーノンナノチューブを含み、且つ、配向性、導電性及び強度に優れたカーボンナノチューブ線材に関する。 The present invention relates to a carbon nanotube wire rod, and more particularly to a carbon nanotube wire rod containing a plurality of carnon nanotubes having an average length of 15 μm or more and having excellent orientation, conductivity and strength.
カーボンナノチューブ（以下、「ＣＮＴ」ということがある。）は、様々な特性を有する素材であり、多くの分野への応用が期待されている。 Carbon nanotubes (hereinafter sometimes referred to as "CNTs") are materials having various properties and are expected to be applied to many fields.
例えば、ＣＮＴは、軽量であると共に、導電性、熱伝導性、機械的強度等の諸特性に優れるため、線材の材料として用いることが考えられる。 For example, CNT is considered to be used as a material for wire rods because it is lightweight and has excellent properties such as conductivity, thermal conductivity, and mechanical strength.
ＣＮＴを線材として使用する場合、ＣＮＴの高配向化・高密度化が高導電化に寄与することが知られている。また、アスペクト比が高いＣＮＴは、ＣＮＴ単体の導電性が高いことも公知であり、高いアスペクト比を有するＣＮＴの使用は高い導電性のＣＮＴ線材の作製に有効であると考えられる。しかしながら、アスペクト比が高い、すなわち長いＣＮＴを使用すると、ＣＮＴ同士の絡まりが強いため、さらなる高導電化、高強度化が期待できる一方で、高配向化が難しい。そのため、高いアスペクト比を有するＣＮＴを高配向化させる技術の開発が望まれている。 When CNTs are used as wire rods, it is known that high orientation and high density of CNTs contribute to high conductivity. It is also known that CNTs having a high aspect ratio have high conductivity of CNTs alone, and it is considered that the use of CNTs having a high aspect ratio is effective for producing highly conductive CNT wires. However, when CNTs having a high aspect ratio, that is, long CNTs are used, the CNTs are strongly entangled with each other, so that higher conductivity and higher strength can be expected, but higher orientation is difficult. Therefore, it is desired to develop a technique for highly orienting CNTs having a high aspect ratio.
また、ＣＮＴ線材の製造方法の１つに、ＣＮＴを含む分散液を作製し、その分散液を凝固液（溶剤）中にてノズル等を介して吐出し、固化しながら繊維化する湿式紡糸が知られている。湿式紡糸では、凝固液中でＣＮＴ分散液を押出（吐出）して糸状のＣＮＴ線材を形成させるため、低粘度のＣＮＴ分散液を用いることも可能である。しかしながら、電線用途として高導電性のＣＮＴ線を作製するためには、長いＣＮＴを分散させた高濃度のＣＮＴ分散液を用いてＣＮＴ密度の高い線材を作製する必要がある。また、通常の湿式紡糸で作製したＣＮＴはランダムに配向しているため、高濃度のＣＮＴ分散液を用いた場合、ＣＮＴが絡まりやすく、配向性がランダムとなる傾向がより顕著になる。さらに、ノズル内での流速の違い、凝固の速さの違い等により、押出の際、糸状のＣＮＴ線材の外側と中心部では配向度の差が生じやすく、また、押出により凝固液中に気泡が発生すると、これに起因して空隙率の増大を招き、配向ムラ・密度ムラが生じるおそれがある。そのため、従来の湿式紡糸では、高い配向性を有するＣＮＴ線材の作製は困難であった。 In addition, one of the methods for manufacturing CNT wire rods is wet spinning in which a dispersion liquid containing CNTs is prepared, and the dispersion liquid is discharged in a coagulating liquid (solvent) through a nozzle or the like to form fibers while solidifying. Are known. In wet spinning, since the CNT dispersion liquid is extruded (discharged) in the coagulation liquid to form a thread-like CNT wire rod, it is also possible to use a low-viscosity CNT dispersion liquid. However, in order to produce a highly conductive CNT wire for electric wires, it is necessary to produce a wire having a high CNT density using a high-concentration CNT dispersion liquid in which long CNTs are dispersed. Further, since the CNTs produced by ordinary wet spinning are randomly oriented, when a high-concentration CNT dispersion liquid is used, the CNTs are likely to be entangled and the orientation tends to be random. Further, due to the difference in the flow velocity in the nozzle, the difference in the speed of solidification, etc., the difference in orientation is likely to occur between the outside and the center of the filamentous CNT wire during extrusion, and bubbles are likely to occur in the coagulating liquid by extrusion. If this occurs, the void ratio may increase due to this, and uneven orientation and uneven density may occur. Therefore, it has been difficult to produce a CNT wire having high orientation by conventional wet spinning.
特許文献１には、長尺でアスペクト比が高いＣＮＴを含む分散液は、ＣＮＴが互いに絡み合いネットワーク構造を容易に形成するため、粘度が高く、また、せん断応を加えるとネットワーク構造が解体され、ＣＮＴ分散液の粘度が下がることが記載されている。しかしながら、ＣＮＴの配向性については記載されていない。また、ＣＮＴ分散液中に導電性を阻害する要因である樹脂が含まれているため、導電性が劣ってしまうことが予想される。 According to Patent Document 1, a dispersion liquid containing CNTs, which is long and has a high aspect ratio, has a high viscosity because the CNTs are entangled with each other to easily form a network structure, and the network structure is disassembled when shearing is applied. It is described that the viscosity of the CNT dispersion liquid decreases. However, the orientation of CNTs is not described. Further, since the CNT dispersion liquid contains a resin that is a factor that inhibits the conductivity, it is expected that the conductivity will be inferior.
非特許文献１には、ＣＮＴに高いせん断力を加えて作製した水平配向膜が記載されている。しかしながら、使用したＣＮＴは、平均長さが４２０ｎｍ以下の短いＣＮＴであるため、平均長さが１０μｍ以上の長いＣＮＴを含む配向膜は得られていない。そのため、ＣＮＴ同士の絡まりは比較的弱く、導電性、強度をさらに向上させる余地がある。 Non-Patent Document 1 describes a horizontally oriented film prepared by applying a high shearing force to CNT. However, since the CNTs used are short CNTs having an average length of 420 nm or less, an alignment film containing a long CNT having an average length of 10 μm or more has not been obtained. Therefore, the entanglement between the CNTs is relatively weak, and there is room for further improving the conductivity and strength.
上記事情に鑑み、本発明の目的は、比較的長いカーボンナノチューブを含み、配向性、導電性及び強度に優れたカーボンナノチューブ線材を提供することである。 In view of the above circumstances, an object of the present invention is to provide a carbon nanotube wire rod containing a relatively long carbon nanotube and having excellent orientation, conductivity and strength.
本発明者は、上記問題に対して鋭意検討を行った結果、カーボンナノチューブを含む分散液に高いせん断力を負荷しながらカーボンナノチューブの塗布膜を作製することにより、比較的長いカーボンナノチューブ同士が絡まった状態で、これらがせん断方向に沿って配向されるとの知見を得た。また、得られた塗布膜を、該塗布膜に含まれるカーボンナノチューブの配向方向がカーボンナノチューブ線材の長手方向と平行になるように半乾きの状態でロール状に巻くことで、カーボンナノチューブ線材の外側と内側で配向度の差がほとんどなく、隣り合ったカーボンナノチューブ層同士がカーボンナノチューブのファンデルワールス力により強固に結合するとの知見を得た。このような製法により得られたカーボンナノチューブ線材は、空隙率が少ない上、配向性が高く、さらには、比較的長いカーボンナノチューブ同士が互いに強く絡み合ったネットワーク構造を形成するため、導電性及び強度に優れたカーボンナノチューブ線材が得られることを見出した。 As a result of diligent studies on the above problems, the present inventor has made a coating film of carbon nanotubes while applying a high shear force to a dispersion liquid containing carbon nanotubes, whereby relatively long carbon nanotubes are entangled with each other. It was found that these are oriented along the shear direction in this state. Further, by winding the obtained coating film in a semi-dry state so that the orientation direction of the carbon nanotubes contained in the coating film is parallel to the longitudinal direction of the carbon nanotube wire, the outside of the carbon nanotube wire is wound. It was found that there is almost no difference in the degree of orientation inside and inside, and that adjacent carbon nanotube layers are firmly bonded to each other by the van der Waals force of carbon nanotubes. The carbon nanotube wire rods obtained by such a manufacturing method have a low void ratio, high orientation, and form a network structure in which relatively long carbon nanotubes are strongly entangled with each other, resulting in high conductivity and strength. It has been found that an excellent carbon nanotube wire rod can be obtained.
すなわち、本発明の要旨構成は、以下の通りである。
［１］ 複数のカーボンナノチューブで構成されるカーボンナノチューブ集合体からなるカーボンナノチューブ線材であって、
前記複数のカーボンナノチューブの平均長さが１５μｍ以上であり、
前記カーボンナノチューブ線材において、前記カーボンナノチューブ線材の円相当半径をＲ、同心円でＲ／√２の半径を有する部分の範囲をカーボンナノチューブ線材の内側、同心円で前記カーボンナノチューブ線材の内側を除いた部分の範囲をカーボンナノチューブ線材の外側としたとき、走査型電子顕微鏡で観察し得られた画像を高速フーリエ変換した画像を解析し算出されるヘルマンの配向係数が、前記カーボンナノチューブ線材の外側で０．７５以上であり、且つ前記カーボンナノチューブ線材の外側におけるヘルマンの配向係数と前記カーボンナノチューブ線材の内側におけるヘルマンの配向係数との差の絶対値が０．０５以下であり、かつ、
前記カーボンナノチューブ線材において、ラマンスペクトルのＧバンドに対する結晶性に由来するＤバンドの比であるＧ／Ｄ比が７０以上であることを特徴とするカーボンナノチューブ線材。
［２］ カーボンナノチューブ線材の径方向における任意の断面積に対する空隙率が１０％以下である、［１］に記載のカーボンナノチューブ線材。
［３］ 密度が１．４ｇ／ｃｍ３以上である、［１］又は［２］に記載のカーボンナノチューブ線材。
［４］ 前記Ｇ／Ｄ比が８０以上である、［１］乃至［３］までのいずれかに記載のカーボンナノチューブ線材。
［５］ 前記複数のカーボンナノチューブの平均長さが２０μｍ以上６０μｍ以下である、［１］乃至［４］までのいずれかに記載のカーボンナノチューブ線材。
［６］ 空隙の分散度が５．０以下である、［１］乃至［５］までのいずれかに記載のカーボンナノチューブ線材。
That is, the gist structure of the present invention is as follows.
[1] A carbon nanotube wire rod composed of an aggregate of carbon nanotubes composed of a plurality of carbon nanotubes.
The average length of the plurality of carbon nanotubes is 15 μm or more, and the average length is 15 μm or more.
In the carbon nanotube wire rod, the circle-equivalent radius of the carbon nanotube wire rod is R, the range of the portion having a radius of R / √2 in the concentric circle is the inside of the carbon nanotube wire rod, and the portion of the concentric circle excluding the inside of the carbon nanotube wire rod. When the range is outside the carbon nanotube wire, the Hermann orientation coefficient calculated by analyzing the image obtained by high-speed Fourier conversion of the image obtained by the scanning electron microscope is 0.75 outside the carbon nanotube wire. The absolute value of the difference between the Hermann orientation coefficient outside the carbon nanotube wire rod and the Hermann orientation coefficient inside the carbon nanotube wire rod is 0.05 or less, and
The carbon nanotube wire rod is characterized in that the G / D ratio, which is the ratio of the D band derived from crystallinity to the G band of the Raman spectrum, is 70 or more.
[2] The carbon nanotube wire rod according to [1], wherein the void ratio with respect to an arbitrary cross-sectional area in the radial direction of the carbon nanotube wire rod is 10% or less.
[3] The carbon nanotube wire rod according to [1] or [2], which has a density of 1.4 g / cm 3 or more.
[4] The carbon nanotube wire rod according to any one of [1] to [3], wherein the G / D ratio is 80 or more.
[5] The carbon nanotube wire rod according to any one of [1] to [4], wherein the average length of the plurality of carbon nanotubes is 20 μm or more and 60 μm or less.
[6] The carbon nanotube wire rod according to any one of [1] to [5], wherein the degree of dispersion of voids is 5.0 or less.
本発明によれば、比較的長いカーボンナノチューブ同士が互いに強く絡み合った状態で配向し、カーボンナノチューブ線材の外側と内側で配向度の差がほとんどなく、隣り合ったカーボンナノチューブ層同士がカーボンナノチューブのファンデルワールス力により強固に結合している。そのため、高配向化が図れると共に、長いカーボンナノチューブ同士がより高密度で結合する。これにより、比較的長いカーボンナノチューブを含みつつ、配向性、導電性及び強度に優れたカーボンナノチューブ線材を提供することができる。 According to the present invention, relatively long carbon nanotubes are oriented in a state of being strongly entangled with each other, there is almost no difference in the degree of orientation between the outside and the inside of the carbon nanotube wire rod, and the adjacent carbon nanotube layers are carbon nanotube fans. It is firmly connected by the Delwars force. Therefore, high orientation can be achieved, and long carbon nanotubes are bonded to each other at a higher density. Thereby, it is possible to provide a carbon nanotube wire rod having excellent orientation, conductivity and strength while containing a relatively long carbon nanotube.
以下に、本発明の実施形態例に係るカーボンナノチューブ線材について、図面を用いながら詳細に説明する。 Hereinafter, the carbon nanotube wire rod according to the embodiment of the present invention will be described in detail with reference to the drawings.
＜カーボンナノチューブ線材＞
図１に示されるように、本発明に係るカーボンナノチューブ線材１０は、複数のＣＮＴ１１ａ，１１ａ，・・・で構成されるＣＮＴ集合体１１からなる。ＣＮＴ集合体１１は、１層以上の層構造を有する複数のＣＮＴ１１ａ，１１ａ，・・・で構成されており、ＣＮＴ線材１０は、ＣＮＴ集合体１１の単数から、または複数が束ねられて形成されている。ここで、ＣＮＴ線材とはＣＮＴの割合が９０質量％以上のＣＮＴ線材を意味する。なお、ＣＮＴ線材におけるＣＮＴ割合の算定においては、メッキとドーパントは除かれる。ＣＮＴ集合体１１の長手方向が、ＣＮＴ線材１０の長手方向を形成しているため、ＣＮＴ集合体１１は、線状となっている。ＣＮＴ線材１０における複数のＣＮＴ集合体１１，１１，・・・は、その長軸方向がほぼ揃って配向している。ＣＮＴ線材１０は、１本のＣＮＴ線材１０からなる素線（単線）である。素線としてのＣＮＴ線材１０の直径は、特に限定されないが、例えば、０．００５ｍｍ以上４．０ｍｍ以下である。また、複数本のＣＮＴ線材１０をさらに撚り合わせることにより、ＣＮＴ線材１０の撚り線を形成することができる。
<Carbon nanotube wire>
As shown in FIG. 1, the carbon nanotube wire rod 10 according to the present invention is composed of a CNT aggregate 11 composed of a plurality of CNTs 11a, 11a, .... The CNT aggregate 11 is composed of a plurality of CNTs 11a, 11a, ... Having a layer structure of one or more layers, and the CNT wire rod 10 is formed from a single number of the CNT aggregates 11 or a bundle of a plurality of the CNT aggregates 11. ing. Here, the CNT wire rod means a CNT wire rod having a CNT ratio of 90% by mass or more. In addition, plating and dopants are excluded in the calculation of the CNT ratio in the CNT wire rod. Since the longitudinal direction of the CNT aggregate 11 forms the longitudinal direction of the CNT wire rod 10, the CNT aggregate 11 is linear. The plurality of CNT aggregates 11, 11, ... In the CNT wire rod 10 are oriented so that their major axis directions are substantially aligned. The CNT wire rod 10 is a wire (single wire) composed of one CNT wire rod 10. The diameter of the CNT wire rod 10 as a wire is not particularly limited, but is, for example, 0.005 mm or more and 4.0 mm or less. Further, by further twisting the plurality of CNT wire rods 10, the stranded wire of the CNT wire rod 10 can be formed.
ラマン分光法を用いて炭素系の物質を解析すると、ラマンシフト１５９０ｃｍ−１付近に、Ｇバンドと呼ばれる、六員環の面内振動に由来するスペクトルのピークが検出される。一方、Ｄバンドは、ラマンシフト１３５０ｃｍ−１付近に現れ、欠陥に由来するスペクトルのピークともいえる。ＣＮＴ線材１０における欠陥量の指標として、ラマンスペクトルのＧバンドに対する結晶性に由来するＤバンドの比であるＧ／Ｄ比が用いられる。Ｇ／Ｄ比が大きい程、ＣＮＴ線材１０に欠陥が少ないと判断できる。ＣＮＴ線材１０において、Ｇ／Ｄ比は７０以上であり、８０以上であることが好ましい。Ｇ／Ｄ比が７０以上であることにより、欠陥が少なく、導電性及び強度に優れたＣＮＴ線材１０を得ることができる。 When a carbon-based substance is analyzed using Raman spectroscopy, a peak of a spectrum derived from in-plane vibration of a six-membered ring called a G band is detected near Raman shift 1590 cm -1 . On the other hand, the D band appears near Raman shift 1350 cm -1 , and can be said to be the peak of the spectrum derived from the defect. As an index of the amount of defects in the CNT wire rod 10, the G / D ratio, which is the ratio of the D band derived from the crystallinity to the G band of the Raman spectrum, is used. It can be determined that the larger the G / D ratio, the fewer defects the CNT wire rod 10 has. In the CNT wire rod 10, the G / D ratio is 70 or more, preferably 80 or more. When the G / D ratio is 70 or more, it is possible to obtain the CNT wire rod 10 having few defects and excellent conductivity and strength.
［ＣＮＴ集合体］
ＣＮＴ集合体１１は、複数のＣＮＴ１１ａの束であり、ＣＮＴ１１ａの長手方向が、ＣＮＴ集合体１１の長手方向を形成している。ＣＮＴ集合体１１における複数のＣＮＴ１１ａ，１１ａ，・・・は、その長軸方向がほぼ揃って配向している。ＣＮＴ集合体１１の円相当直径は、例えば、２０ｎｍ以上１０００ｎｍ以下であり、より典型的には、２０ｎｍ以上８０ｎｍ以下である。
[CNT aggregate]
The CNT aggregate 11 is a bundle of a plurality of CNTs 11a, and the longitudinal direction of the CNTs 11a forms the longitudinal direction of the CNT aggregates 11. The plurality of CNTs 11a, 11a, ... In the CNT aggregate 11 are oriented so that their major axis directions are substantially aligned. 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.
［ＣＮＴ］
ＣＮＴ集合体１１を構成するＣＮＴ１１ａは、単層構造又は複層構造を有する筒状体が糸状に形成された物質であり、単層構造のＣＮＴはＳＷＮＴ（single-walled nanotube）、複層構造のＣＮＴはＭＷＮＴ（multi-walled nanotube）と呼ばれる。図１では、便宜
上、２層構造を有するＣＮＴ１１ａのみを記載しているが、ＣＮＴ集合体１１には、３層構造を有するＣＮＴまたは単層構造の層構造を有するＣＮＴも含まれていてもよく、３層構造を有するＣＮＴまたは単層構造の層構造を有するＣＮＴから形成されていてもよい。但し、ＣＮＴが４層構造以上であると、ＣＮＴの径のサイズおよび分布が大きくなり、ＣＮＴ同士が絡みにくくなる。そのため、ＣＮＴは、単層構造、２層構造または３層構造であることが好ましく、単層構造または２層構造であることがより好ましく、２層構造であることがさらに好ましい。
[CNT]
The CNT 11a constituting the CNT aggregate 11 is a substance in which a tubular body having a single-walled structure or a multi-walled structure is formed in a thread shape, and the CNT having a single-walled structure is a SWNT (single-walled nanotube) having a multi-walled structure. CNTs are called MWNTs (multi-walled nanotubes). In FIG. 1, for convenience, only CNTs 11a having a two-layer structure are shown, but the CNT aggregate 11 may also include CNTs having a three-layer structure or CNTs having a single-walled structure. It may be formed from CNTs having a three-layer structure or CNTs having a single-walled structure. However, when the CNTs have a four-layer structure or more, the size and distribution of the diameters of the CNTs become large, and the CNTs are less likely to be entangled with each other. Therefore, the CNT preferably has a single-layer structure, a two-layer structure, or a three-layer structure, more preferably a single-layer structure or a two-layer structure, and further preferably a two-layer structure.
２層構造を有するＣＮＴ１１ａでは、六角形格子の網目構造を有する２つの筒状体Ｔ１、Ｔ２が略同軸で配された３次元網目構造体となっており、ＤＷＮＴ（double-walled nanotube）と呼ばれる。構成単位である六角形格子は、その頂点に炭素原子が配された六員環であり、他の六員環と隣接してこれらが連続的に結合している。 The CNT11a having a two-layer structure is a three-dimensional network structure in which two tubular bodies T1 and T2 having a hexagonal lattice network structure are arranged substantially coaxially, and is called a DWNT (double-walled nanotube). .. The hexagonal lattice, which is a constituent unit, is a six-membered ring in which carbon atoms are arranged at its vertices, and these are continuously bonded adjacent to other six-membered rings.
ＣＮＴ１１ａの性質は、上記筒状体のカイラリティ（chirality）に依存する。カイラ
リティは、アームチェア型、ジグザグ型、及びカイラル型に大別され、アームチェア型は金属性、ジグザグ型は半導体性および半金属性、カイラル型は半導体性および半金属性の挙動を示す。従って、ＣＮＴ１１ａの導電性は、筒状体がいずれのカイラリティを有するかによって大きく異なる。
The properties of CNT11a depend on the chirality of the tubular body. Chirality is roughly classified into an armchair type, a zigzag type, and a chiral type. The armchair type exhibits metallic behavior, the zigzag type exhibits semiconductor and semimetallic behavior, and the chiral type exhibits semiconductor and semimetallic behavior. Therefore, the conductivity of the CNT 11a varies greatly depending on which chirality the tubular body has.
一方で、半導体性の挙動を示すカイラル型のＣＮＴ１１ａに電子供与性もしくは電子受容性を持つ物質（異種元素）をドープすることにより、カイラル型のＣＮＴ１１ａが金属性の挙動を示すことが分かっている。また、一般的な金属では、異種元素をドープすることによって金属内部での伝導電子の散乱が起こって導電性が低下するが、これと同様に、金属性の挙動を示すＣＮＴ１１ａに異種元素をドープした場合には、導電性の低下を引き起こす。 On the other hand, it is known that the chiral type CNT11a exhibits metallic behavior by doping the chiral type CNT11a exhibiting semiconducting behavior with a substance (dissimilar element) having electron donating property or electron accepting property. .. Further, in a general metal, by doping a dissimilar element, conduction electrons are scattered inside the metal and the conductivity is lowered. Similarly, CNT11a exhibiting a metallic behavior is doped with a dissimilar element. If so, it causes a decrease in conductivity.
［ＣＮＴの長さ］
複数のＣＮＴ１１ａ，１１ａ，・・・において、複数のＣＮＴ１１ａ，１１ａ，・・・の平均長さ（以下、単に「平均長さ」ともいう）の下限値は１５μｍ以上であり、２０μｍ以上であることが好ましい。平均長さが１５μｍ未満であると、長いＣＮＴが少な過ぎるため、ＣＮＴ線材１０において、長さ方向（長手方向）の導電パスが短く、優れた導電性を得ることが困難である。また、長いＣＮＴ同士の繋がりが少ないため、優れた強度を得ることも困難となる。一方、ＣＮＴの平均長さが長いほど、高アスペクト比を有するＣＮＴ同士が互いに絡まって繋がりを形成しやすい。これにより、ＣＮＴ線材１０の長さ方向（長手方向）に沿って安定して導電性が付与され、また、ＣＮＴ同士の絡み合いにより強度も向上する。複数のＣＮＴ１１ａ，１１ａ，・・・において、平均長さの上限値は特に制限はないが、長いＣＮＴ同士が過剰に絡み合うことを抑制するため、平均長さの上限値は１２０μｍ以下であることが好ましく、６０μｍ以下であることが好ましい。特に、複数のＣＮＴ１１ａ，１１ａ，・・・の平均長さが２０μｍ以上６０μｍ以下であることにより、ＣＮＴ線材１０の長さ方向（長手方向）の導電パスが高まるため、優れた導電性を確保しやすく、また、複数のＣＮＴ１１ａ，１１ａ，・・・が一定の方向に適度に配向しやすい長さであるため、後述する配向性を高めることができる。
[Length of CNT]
In a plurality of CNTs 11a, 11a, ..., The lower limit of the average length of the plurality of CNTs 11a, 11a, ... (hereinafter, also simply referred to as "average length") is 15 μm or more, and 20 μm or more. Is preferable. If the average length is less than 15 μm, there are too few long CNTs, so that the conductive path in the length direction (longitudinal direction) is short in the CNT wire rod 10, and it is difficult to obtain excellent conductivity. Further, since there are few connections between long CNTs, it is difficult to obtain excellent strength. On the other hand, the longer the average length of CNTs, the easier it is for CNTs having a high aspect ratio to be entangled with each other to form a connection. As a result, conductivity is stably imparted along the length direction (longitudinal direction) of the CNT wire rod 10, and the strength is also improved by the entanglement of the CNTs. The upper limit of the average length of a plurality of CNTs 11a, 11a, ... Is not particularly limited, but the upper limit of the average length may be 120 μm or less in order to prevent excessive entanglement of long CNTs. It is preferably 60 μm or less. In particular, when the average length of the plurality of CNTs 11a, 11a, ... Is 20 μm or more and 60 μm or less, the conductive path in the length direction (longitudinal direction) of the CNT wire rod 10 is enhanced, so that excellent conductivity is ensured. It is easy, and since the plurality of CNTs 11a, 11a, ... Are long enough to be appropriately oriented in a certain direction, the orientation described later can be enhanced.
［ＣＮＴの径］
複数のＣＮＴ１１ａ，１１ａ，・・・において、複数のＣＮＴ１１ａ，１１ａ，・・・
の平均径（以下、単に「平均径」ともいう）は特に限定されるものではないが、２．０ｎｍ以下であることが好ましい。これにより、高アスペクト比を有するＣＮＴの割合が増大し、長いＣＮＴ同士が互いに絡まって繋がったネットワーク構造を形成しやすくなる。複数のＣＮＴ１１ａ，１１ａ，・・・において、平均径の下限値は特に制限はないが、１．０ｎｍ以上であることが好ましい。
[Diameter of CNT]
In a plurality of CNTs 11a, 11a, ..., A plurality of CNTs 11a, 11a, ...
The average diameter of the above (hereinafter, also simply referred to as “average diameter”) is not particularly limited, but is preferably 2.0 nm or less. As a result, the proportion of CNTs having a high aspect ratio increases, and it becomes easy to form a network structure in which long CNTs are entwined and connected to each other. In the plurality of CNTs 11a, 11a, ..., The lower limit of the average diameter is not particularly limited, but is preferably 1.0 nm or more.
［ＣＮＴの配向性］
ＣＮＴ線材１０において、複数のＣＮＴ１１ａ，１１ａ，・・・の配向性は、ヘルマンの配向係数により評価することができる。図２にＣＮＴ線材１０における配向性の測定部分を示す。図２（ａ）は、ＣＮＴ線材１０の短軸方向（径方向）の断面図であり、図２（ｂ）は、ＣＮＴ線材１０の長軸方向（長さ方向）の断面図である。具体的には、ＣＮＴ線材１０において、ＣＮＴ線材１０の円相当半径をＲ、同心円でＲ／√２の半径を有する部分の範囲をＣＮＴ線材１０の内側２０、同心円でＣＮＴ線材１０の内側２０を除いた部分、すなわち、Ｒ−（Ｒ／√２）の厚さを有する中空円部分の範囲をＣＮＴ線材１０の外側３０としたとき、ＣＮＴ線材１０の外側３０における配向度と、ＣＮＴ線材１０の外側３０における配向度とＣＮＴ線材１０の内側２０における配向度の差を測定する。これらの配向度は、ヘルマンの配向係数によって評価される。ＣＮＴ線材１０において、ヘルマンの配向係数が、ＣＮＴ線材１０の外側３０で０．７５以上であり、且つＣＮＴ線材１０の外側３０におけるヘルマンの配向係数とＣＮＴ線材１０の内側２０におけるヘルマンの配向係数との差の絶対値が０．０５以下であることにより、ＣＮＴ線材１０は高い配向性を有していると判断される。ヘルマンの配向係数の上限値は１未満であり、ヘルマンの配向係数が１に近いほど高い配向性を有していることを意味する。また、ＣＮＴ線材１０の外側３０におけるヘルマンの配向係数とＣＮＴ線材１０の内側２０におけるヘルマンの配向係数との差の絶対値が０に近いほど、複数のＣＮＴ１１ａ，１１ａ・・・がＣＮＴ線材１０の外側３０と内側２０のそれぞれで均一に配向していると判断できる。ＣＮＴ線材１０の外側３０におけるヘルマン配向係数および内側２０におけるヘルマンの配向係数は、走査型電子顕微鏡で観察し得られた画像（ＳＥＭ画像）を高速フーリエ変換した画像を解析（ＦＦＴ解析）して算出される。例えば、イオンミリングを用いてＣＮＴ線材１０を長軸方向に沿って切断し、その切断面をＳＥＭ（走査型電子顕微鏡）で観察し、当該切断面におけるＳＥＭ画像のＦＦＴ配向解析を行うことでこれらの配向係数を測定できる。
[Orientation of CNT]
In the CNT wire rod 10, the orientation of the plurality of CNTs 11a, 11a, ... Can be evaluated by the orientation coefficient of Hermann. FIG. 2 shows a measurement portion of orientation in the CNT wire rod 10. FIG. 2A is a cross-sectional view of the CNT wire rod 10 in the minor axis direction (diameter direction), and FIG. 2B is a cross-sectional view of the CNT wire rod 10 in the major axis direction (longitudinal direction). Specifically, in the CNT wire 10, the circle-equivalent radius of the CNT wire 10 is R, the range of the concentric circles having a radius of R / √2 is the inside 20 of the CNT wire 10, and the concentric circles are the inside 20 of the CNT wire 10. When the range of the excluded portion, that is, the hollow circular portion having a thickness of R- (R / √2) is defined as the outer side 30 of the CNT wire rod 10, the degree of orientation of the CNT wire rod 10 on the outer side 30 and the degree of orientation of the CNT wire rod 10 The difference between the degree of orientation on the outer side 30 and the degree of orientation on the inner side 20 of the CNT wire rod 10 is measured. These degrees of orientation are evaluated by Hermann's alignment coefficient. In the CNT wire 10, the Hermann orientation coefficient is 0.75 or more on the outside 30 of the CNT wire 10, and the Hermann orientation coefficient on the outside 30 of the CNT wire 10 and the Hermann orientation coefficient on the inside 20 of the CNT wire 10. It is judged that the CNT wire rod 10 has high orientation when the absolute value of the difference between the two is 0.05 or less. The upper limit of the Hermann orientation coefficient is less than 1, and the closer the Hermann orientation coefficient is to 1, the higher the orientation. Further, the closer the absolute value of the difference between the Hermann orientation coefficient on the outer side 30 of the CNT wire 10 and the Hermann orientation coefficient on the inner side 20 of the CNT wire 10 is to 0, the more a plurality of CNTs 11a, 11a ... It can be determined that the outer side 30 and the inner side 20 are uniformly oriented. The Hermann orientation coefficient on the outer side 30 and the Hermann orientation coefficient on the inner side 20 of the CNT wire 10 are calculated by analyzing (FFT analysis) an image obtained by fast Fourier transforming an image (SEM image) obtained by observing with a scanning electron microscope. Will be done. For example, the CNT wire rod 10 is cut along the long axis direction using ion milling, the cut surface is observed with an SEM (scanning electron microscope), and the FFT orientation analysis of the SEM image on the cut surface is performed. Orientation coefficient can be measured.
ＣＮＴ線材１０の外側３０におけるヘルマンの配向係数が０．７５以上であることにより、ＣＮＴ線材１０の外側３０では、平均長さが１５μｍ以上の複数のＣＮＴ１１ａ，１１ａ，・・・がＣＮＴ線材１０の長軸方向にほぼ揃って配向していると判断できる。すなわち、ＣＮＴ線材１０の外側３０には、高い配向性が付与されている。また、ＣＮＴ線材１０の外側３０におけるヘルマンの配向係数とＣＮＴ線材１０の内側２０におけるヘルマンの配向係数との差の絶対値が０．０５以下であることにより、ＣＮＴ線材１０の外側３０と内側２０において、複数のＣＮＴ１１ａ，１１ａ，・・・が均一に配向されていると判断できる。すなわち、ＣＮＴ線材１０の空隙率が低く、平均長さが１５μｍ以上の複数のＣＮＴ１１ａ，１１ａ，・・・がより高密度に配向されている。このように、ＣＮＴ線材１０が所定の配向性を満たすことにより、導電性及び強度に優れたＣＮＴ線材１０を得ることができる。特に、ＣＮＴ線材１０の外側３０におけるヘルマンの配向係数が０．８５以上であり、且つＣＮＴ線材１０の外側３０におけるヘルマンの配向係数とＣＮＴ線材１０の内側２０におけるヘルマンの配向係数との差の絶対値が０．０３以下であることにより、より配向性に優れたＣＮＴ線材１０を得ることができ、ＣＮＴ１１ａの平均長さが２０μｍ以上６０μｍ以下の場合、効果がより顕著になる。 Since the orientation coefficient of Hermann on the outer side 30 of the CNT wire 10 is 0.75 or more, on the outer side 30 of the CNT wire 10, a plurality of CNTs 11a, 11a, ... With an average length of 15 μm or more are formed on the CNT wire 10. It can be judged that the orientation is almost aligned in the long axis direction. That is, the outer side 30 of the CNT wire rod 10 is provided with high orientation. Further, since the absolute value of the difference between the Hermann orientation coefficient on the outer side 30 of the CNT wire 10 and the Hermann orientation coefficient on the inner side 20 of the CNT wire 10 is 0.05 or less, the outer 30 and the inner 20 of the CNT wire 10 are 20 or less. It can be determined that the plurality of CNTs 11a, 11a, ... Are uniformly oriented. That is, a plurality of CNTs 11a, 11a, ... With a low void ratio of the CNT wire rod 10 and an average length of 15 μm or more are oriented at a higher density. By satisfying the predetermined orientation of the CNT wire 10 in this way, the CNT wire 10 having excellent conductivity and strength can be obtained. In particular, the Hermann orientation coefficient on the outer side 30 of the CNT wire 10 is 0.85 or more, and the absolute difference between the Hermann orientation coefficient on the outer side 30 of the CNT wire 10 and the Hermann orientation coefficient on the inner side 20 of the CNT wire 10 is absolute. When the value is 0.03 or less, the CNT wire rod 10 having more excellent orientation can be obtained, and when the average length of the CNT 11a is 20 μm or more and 60 μm or less, the effect becomes more remarkable.
［密度］
ＣＮＴ線材１０は、密度が０．８ｇ／ｃｍ３以上であることが好ましく、１．０ｇ／ｃｍ３以上であることがより好ましく、１．４ｇ／ｃｍ３以上であることがさらに好ましい
。密度が０．８ｇ／ｃｍ３以上であれば、ＣＮＴ線材１０に優れた強度を付与することができ、密度が１．０ｇ／ｃｍ３以上であることにより、より強度を向上させることができ、特に、密度が１．４ｇ／ｃｍ３以上であることにより、顕著に優れた強度が付与される。
[density]
The density of the CNT wire rod 10 is preferably 0.8 g / cm 3 or more, more preferably 1.0 g / cm 3 or more, and further preferably 1.4 g / cm 3 or more. When the density is 0.8 g / cm 3 or more, excellent strength can be imparted to the CNT wire rod 10, and when the density is 1.0 g / cm 3 or more, the strength can be further improved. In particular, when the density is 1.4 g / cm 3 or more, remarkably excellent strength is imparted.
［ＣＮＴ線材の製造方法］
ＣＮＴ１１ａは、浮遊触媒法（特許第５８１９８８８号公報）、基板法（特許第５５９０６０３号公報）等の方法により作製することができ、好ましくは浮遊触媒法により作製される。浮遊触媒法の条件は、特に限定されるものではなく、従来公知の方法により適宜設計することができる。これにより、複数のＣＮＴ１１ａ，１１ａ，・・・を含む分散液が作製される。
[Manufacturing method of CNT wire]
CNT11a can be produced by a method such as a floating catalyst method (Patent No. 5819888) or a substrate method (Patent No. 5590603), and is preferably produced by a floating catalyst method. The conditions of the floating catalyst method are not particularly limited, and can be appropriately designed by a conventionally known method. As a result, a dispersion liquid containing a plurality of CNTs 11a, 11a, ... Is produced.
ＣＮＴ線材１０の製造方法は、ＣＮＴ分散液を作製する工程と、塗布膜を作製する工程と、ＣＮＴを線材化する工程を含む。ＣＮＴ分散液を作製する工程では、例えば、上述の浮遊触媒法で作製した複数のＣＮＴ１１ａ，１１ａ，・・・を使用してもよい。ＣＮＴ分散液には、溶媒としての水と、所定の平均長さを有する複数のＣＮＴ１１ａ，１１ａ，・・・と、所定量の分散剤（界面活性剤）とが含まれている。但し、ＣＮＴ分散液には、導電性が阻害され、配向性を劣化させる要因となるポリビニルピロリドン（ＰＶＰ）等の樹脂、危険が伴う硫酸、クロロスルホン酸等の強酸は含まない。これらを含む溶液を超音波分散等の分散処理を行うことによりＣＮＴ分散液を作製する。ＣＮＴ分散液中に含まれる複数のＣＮＴ１１ａ，１１ａ，・・・の含有量は、水の量（１００質量％）に対して０．０５質量％以上５．０質量％以下であることが好ましい。また、ＣＮＴ分散液は、水の量（１００質量）に対して０．５質量％以上１０質量％以下の分散剤を含んでいる。 The method for producing the CNT wire rod 10 includes a step of preparing a CNT dispersion liquid, a step of preparing a coating film, and a step of converting CNT into a wire rod. In the step of producing the CNT dispersion liquid, for example, a plurality of CNTs 11a, 11a, ... Produced by the above-mentioned floating catalyst method may be used. The CNT dispersion liquid contains water as a solvent, a plurality of CNTs 11a, 11a, ... Having a predetermined average length, and a predetermined amount of a dispersant (surfactant). However, the CNT dispersion liquid does not contain a resin such as polyvinylpyrrolidone (PVP), which inhibits conductivity and causes deterioration of orientation, and a strong acid such as sulfuric acid and chlorosulfonic acid, which are dangerous. A CNT dispersion liquid is prepared by subjecting a solution containing these to a dispersion treatment such as ultrasonic dispersion. The content of the plurality of CNTs 11a, 11a, ... Contained in the CNT dispersion is preferably 0.05% by mass or more and 5.0% by mass or less with respect to the amount of water (100% by mass). Further, the CNT dispersion liquid contains 0.5% by mass or more and 10% by mass or less of the dispersant with respect to the amount of water (100% by mass).
分散剤として使用される界面活性剤は、特に限定されるものではないが、例えば、陰イオン性界面活性剤等が挙げられ、特にコール酸ナトリウムが好ましい。このような界面活性剤は、１種単独であってもよく、２種以上を併用してもよい。 The surfactant used as the dispersant is not particularly limited, and examples thereof include anionic surfactants, and sodium cholic acid is particularly preferable. Such a surfactant may be used alone or in combination of two or more.
ＣＮＴ線材１０が、１５μｍ以上の平均長さを有する複数のＣＮＴ１１ａ，１１ａ，・・・から形成されるようにするため、ＣＮＴ分散液中に含まれる複数のＣＮＴ１１ａ，１１ａ，・・・の平均長さは１５μｍ以上である。ＣＮＴ分散液中に含まれる複数のＣＮＴ１１ａ，１１ａ，・・・の大きさは、ＣＮＴ分散液中で制御してもよく、複数のＣＮＴ１１ａ，１１ａ，・・・の作製段階で制御してもよい。このように、ＣＮＴ分散液は、比較的長い複数のＣＮＴ１１ａ，１１ａ，・・・を含むため、ゲル状またはペースト状の比較的高粘度のＣＮＴ分散液として存在する。尚、後述する塗布膜の作製工程において負荷する所定のせん断力にはＣＮＴ同士の絡まりを解き、高配向化させる効果があるが、ＣＮＴの短尺化には影響を与えないことを確認している。したがって、分散液中のＣＮＴの平均長さと塗布膜に含まれるＣＮＴが有する平均長さは実質変化しない。 The average length of the plurality of CNTs 11a, 11a, ... Contained in the CNT dispersion liquid so that the CNT wire 10 is formed of the plurality of CNTs 11a, 11a, ... With an average length of 15 μm or more. The size is 15 μm or more. The size of the plurality of CNTs 11a, 11a, ... Contained in the CNT dispersion liquid may be controlled in the CNT dispersion liquid, or may be controlled at the production stage of the plurality of CNTs 11a, 11a, ... .. As described above, since the CNT dispersion liquid contains a plurality of relatively long CNTs 11a, 11a, ..., It exists as a gel-like or paste-like relatively high-viscosity CNT dispersion liquid. It has been confirmed that the predetermined shearing force applied in the process of producing the coating film, which will be described later, has the effect of untangling the CNTs and making them highly oriented, but does not affect the shortening of the CNTs. .. Therefore, the average length of the CNTs in the dispersion and the average length of the CNTs contained in the coating film do not substantially change.
塗布膜を作製する工程では、得られたＣＮＴ分散液を、フッ素樹脂等の基材上に所定のせん断力を負荷しながら塗布し、ＣＮＴ１１ａ，１１ａ，・・・がせん断方向に沿って配向された膜を作製する。所定のせん断力を負荷しつつＣＮＴ分散液を塗布する方法は、特に限定されるものではないが、例えば、バーコーター塗工法等の一般的に公知の方法において、塗布速度を調整することにより、塗布膜に負荷されるせん断力を変更することができる。また、塗布膜の厚さは、その後の乾燥工程における乾燥時間および剥離工程における剥離の容易さの点から、１０μｍ以上１０００μｍ以下であることが好ましく、５０μｍ以上５００μｍ以下であることがより好ましい。 In the step of producing the coating film, the obtained CNT dispersion liquid is applied onto a base material such as fluororesin while applying a predetermined shearing force, and the CNTs 11a, 11a, ... Are oriented along the shearing direction. Shear membrane is prepared. The method of applying the CNT dispersion liquid while applying a predetermined shearing force is not particularly limited, but for example, in a generally known method such as a bar coater coating method, by adjusting the coating rate, the CNT dispersion liquid is applied. The shear force applied to the coating film can be changed. The thickness of the coating film is preferably 10 μm or more and 1000 μm or less, and more preferably 50 μm or more and 500 μm or less, from the viewpoint of the drying time in the subsequent drying step and the ease of peeling in the peeling step.
ＣＮＴ分散液は、高いせん断速度域で低粘度を示す。低いせん断速度域では、複数のＣＮＴ１１ａ，１１ａ，・・・同士が絡み合っているものの、高いせん断速度域では、せん
断により絡み合いが適度に解れ、せん断方向に沿ってＣＮＴが配向する。これにより、複数のＣＮＴ１１ａ，１１ａ，・・・同士が適度に絡まった状態で、これらがせん断方向に沿って配向した高配向膜を得ることができる。塗布膜の形成の際、高いせん断力を負荷させるため、塗布速度は０．００１ｍ／ｓ以上５ｍ／ｓ以下であることが好ましい。尚、高いせん断速度とは、低いせん断速度よりも大きいことを意味し、低いせん断速度は、０．１［１／ｓ］以上１［１／ｓ］未満の範囲を意味する。
The CNT dispersion liquid exhibits low viscosity in a high shear rate range. In the low shear rate range, a plurality of CNTs 11a, 11a, ... Are entangled with each other, but in the high shear rate range, the entanglement is appropriately disentangled by shearing, and the CNTs are oriented along the shear direction. As a result, it is possible to obtain a highly oriented film in which a plurality of CNTs 11a, 11a, ... Are appropriately entangled with each other and oriented along the shear direction. When forming the coating film, a high shearing force is applied, so that the coating speed is preferably 0.001 m / s or more and 5 m / s or less. The high shear rate means that the shear rate is higher than the low shear rate, and the low shear rate means a range of 0.1 [1 / s] or more and less than 1 [1 / s].
ＣＮＴを線材化する工程では、得られた塗布膜を半乾きの状態にし、塗布膜に含まれる複数のＣＮＴ１１ａ，１１ａ，・・・の配向方向がＣＮＴ線材１０の長手方向と平行（同じ方向）になるようにロール状に巻く。例えば、まず、得られた塗布膜を一晩乾燥させる。その後、塗布膜の淵をピンセット等で剥がし、ピンセットを用いて塗布膜をロール状に巻く。ロール状の塗布膜を蒸留水に浸して引き上げ、乾燥させる。乾燥条件は、特に限定されるものではないが、例えば、室温（２５℃前後）で１時間〜一晩放置させる自然乾燥が挙げられる。 In the step of converting the CNT into a wire, the obtained coating film is made semi-dry, and the orientation directions of the plurality of CNTs 11a, 11a, ... Contained in the coating film are parallel to the longitudinal direction of the CNT wire 10 (the same direction). Roll it into a roll so that it becomes. For example, first, the obtained coating film is dried overnight. After that, the edge of the coating film is peeled off with tweezers or the like, and the coating film is rolled into a roll using tweezers. The roll-shaped coating film is immersed in distilled water, pulled up, and dried. The drying conditions are not particularly limited, and examples thereof include natural drying in which the product is left to stand at room temperature (around 25 ° C.) for 1 hour to overnight.
塗布膜に含まれる複数のＣＮＴ１１ａ，１１ａ，・・・の配向方向は、得られるＣＮＴ線材１０の長手方向と平行（同じ）であり、塗布膜の配向性に従いＣＮＴ線材１０には高配向性が付与される。また、塗布膜を半乾きの状態でロール状に巻き、乾燥させることにより、隣り合ったＣＮＴ層同士がＣＮＴのファンデルワールス力により強固に結合する。塗布膜が濡れている状態では、ＣＮＴ層表面に水層が存在するため、ファンデルワールス力による引力が阻害される。一方、塗布膜が乾燥して水分が抜けることにより、ＣＮＴのファンデルワールス力によりＣＮＴ層間の距離が縮まり、最終的にはＣＮＴ層同士が絡まって、ファンデルワールス力により強固に結合する。また、樹脂等の接着剤を用いることなくＣＮＴ層同士が強固に結合するため、導電性も阻害されない。 The orientation direction of the plurality of CNTs 11a, 11a, ... Contained in the coating film is parallel (same) to the longitudinal direction of the obtained CNT wire rod 10, and the CNT wire rod 10 has high orientation according to the orientation of the coating film. Granted. Further, by winding the coating film in a roll shape in a semi-dry state and drying it, adjacent CNT layers are firmly bonded to each other by the van der Waals force of CNT. When the coating film is wet, an aqueous layer is present on the surface of the CNT layer, so that the attractive force due to the Van der Waals force is inhibited. On the other hand, when the coating film dries and moisture is removed, the distance between the CNT layers is shortened by the van der Waals force of the CNTs, and finally the CNT layers are entangled with each other and are firmly bonded by the van der Waals force. Further, since the CNT layers are firmly bonded to each other without using an adhesive such as a resin, the conductivity is not impaired.
従来の湿式紡糸では、押出で糸状のＣＮＴ線材を作製すると、ノズル内での流速の違い、凝固速度の違いにより糸状のＣＮＴ線材の外側と内側で密度及び配向度の差が生じやすい。また、押出で糸状のＣＮＴ線材を作製する湿式紡糸では、大きな気泡（断面観察において数十μμｍの直径）がＣＮＴ線材に混入し、空隙率が高くなりやすい。そのため、ＣＮＴ線材の切断箇所によって、配向ムラ、密度のムラが生じる傾向にあった。これに対し、本発明におけるＣＮＴ線材１０の製造方法では、一様に作製した塗布膜を巻いて糸状のＣＮＴ線材を作製するため、ＣＮＴ線材１０の外側３０と内側２０で配向度の差が生じにくい。さらに、本発明におけるＣＮＴ線材１０の製造方法では、ＣＮＴ線材１０内に大きな気泡が混入しにくく、仮にＣＮＴ線材１０内に気泡が混入しても、配向膜の厚内に存在する数μｍ程度の大きさに抑えられる。また、せん断力を負荷しながら塗布膜を作製するため、ＣＮＴ線材１０の外側３０と内側２０で複数のＣＮＴ１１ａ，１１ａ，・・・がほぼ均一に配向している。そのため、ＣＮＴ線材１０の切断箇所に応じた、配向ムラ、密度のムラが抑制される。 In conventional wet spinning, when a thread-like CNT wire is produced by extrusion, a difference in density and degree of orientation is likely to occur between the outside and the inside of the thread-like CNT wire due to a difference in flow velocity in the nozzle and a difference in solidification rate. Further, in wet spinning in which a thread-like CNT wire is produced by extrusion, large bubbles (diameter of several tens of μm in cross-sectional observation) are mixed in the CNT wire, and the void ratio tends to be high. Therefore, there is a tendency for uneven orientation and uneven density to occur depending on the cut portion of the CNT wire rod. On the other hand, in the method for producing the CNT wire rod 10 in the present invention, since the uniformly prepared coating film is wound to prepare the filamentous CNT wire rod, a difference in the degree of orientation occurs between the outer side 30 and the inner side 20 of the CNT wire rod 10. Hateful. Further, in the method for producing the CNT wire 10 in the present invention, it is difficult for large bubbles to be mixed in the CNT wire 10, and even if the bubbles are mixed in the CNT wire 10, it is about several μm existing in the thickness of the alignment film. It can be suppressed to a size. Further, in order to prepare the coating film while applying a shearing force, a plurality of CNTs 11a, 11a, ... Are oriented substantially uniformly on the outer side 30 and the inner side 20 of the CNT wire rod 10. Therefore, uneven orientation and uneven density depending on the cut portion of the CNT wire rod 10 are suppressed.
＜特性＞
［導電性］
本発明に係るＣＮＴ線材１０は、導電性として、体積抵抗率が８．０×１０−５Ω・ｃｍ未満であることが好ましく、４．０×１０−５Ω・ｃｍ未満であることがより好ましく、１．０×１０−５Ω・ｃｍ未満であることがさらに好ましい。体積抵抗率が８．０×１０−５Ω・ｃｍ未満であれば、導電性に優れていると評価できる。
<Characteristics>
[Conductivity]
The CNT wire rod 10 according to the present invention preferably has a volume resistivity of less than 8.0 × 10-5 Ω · cm and more preferably less than 4.0 × 10-5 Ω · cm in terms of conductivity. It is preferably less than 1.0 × 10-5 Ω · cm, even more preferably. If the volume resistivity is less than 8.0 × 10-5 Ω · cm, it can be evaluated that the conductivity is excellent.
［強度］
本発明に係るＣＮＴ線材１０は、引張強度が１００ＭＰａ以上であることが好ましく、１５０ＭＰａ以上であることがより好ましく、２００ＭＰａ以上であることがさらに好ましい。引張強度が１００ＭＰａ以上であれば、強度に優れていると評価できる。
[Strength]
The CNT wire rod 10 according to the present invention preferably has a tensile strength of 100 MPa or more, more preferably 150 MPa or more, and even more preferably 200 MPa or more. If the tensile strength is 100 MPa or more, it can be evaluated that the strength is excellent.
[空隙率］
本発明に係るＣＮＴ線材１０は、ＣＮＴ線材１０の径方向（短軸方向）における任意の断面積に対する空隙率が１０％以下であることが好ましく、８％以下であることがより好ましい。空隙率が１０％以下であれば、ＣＮＴ線材１０において、空隙に起因する導電パスの妨げを抑制することができ、また、局所的に強度が低い箇所が少なくなるため、ＣＮＴ線材１０の強度、耐久性が向上する。
[Void ratio]
In the CNT wire rod 10 according to the present invention, the void ratio with respect to an arbitrary cross-sectional area in the radial direction (minor axis direction) of the CNT wire rod 10 is preferably 10% or less, and more preferably 8% or less. When the void ratio is 10% or less, the CNT wire 10 can suppress the obstruction of the conductive path due to the voids, and the strength of the CNT wire 10 is reduced because the number of locally low strength points is reduced. Durability is improved.
[空隙の分散］
本発明に係るＣＮＴ線材１０は、空隙の分散度が５．０以下であることが好ましく、４．０以下であることがより好ましい。空隙の分散度が５．０以下であれば、ＣＮＴ線材１０において、空隙に起因する導電パスの妨げを抑制することができ、また、局所的に強度が低い箇所が少なくなるため、ＣＮＴ線材１０の強度、耐久性が向上する。尚、ＣＮＴ線材１０における空隙の分散度は、例えば、上記の空隙率を、ＣＮＴ線材１０の径方向における任意の５箇所の断面で測定し、その標準偏差から算出できる。
[Dispersion of voids]
The CNT wire rod 10 according to the present invention preferably has a void dispersion degree of 5.0 or less, and more preferably 4.0 or less. When the degree of dispersion of the voids is 5.0 or less, the CNT wire 10 can suppress the obstruction of the conductive path due to the voids, and the number of locally low strength points is reduced. Strength and durability are improved. The degree of dispersion of voids in the CNT wire 10 can be calculated from, for example, the above-mentioned void ratio measured at any five cross sections in the radial direction of the CNT wire 10 and its standard deviation.
本発明に係るＣＮＴ線材は、自動車、電気機器、制御機器等の様々な分野における電力線、信号線としての電線を構成する導体として使用することができ、特に、車両用のワイヤハーネス、モーター等の一般電線の導体としての使用に好適である。 The CNT wire rod according to the present invention can be used as a conductor constituting an electric wire as a power line or a signal line in various fields such as automobiles, electric devices, control devices, etc., and in particular, wire harnesses for vehicles, motors, etc. Suitable for use as a conductor for general electric wires.
以下、本発明を実施例に基づきさらに詳細に説明するが、本発明はこれらに限定されるものではない。 Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.
＜ＣＮＴ線材の作製＞
実施例１〜１２、比較例１〜７について、以下のようにしてＣＮＴ線材を作製した。
<Manufacturing of CNT wire rod>
For Examples 1 to 12 and Comparative Examples 1 to 7, CNT wire rods were prepared as follows.
［実施例１〜１２、比較例１、５〜７について］
浮遊触媒法でＣＮＴを作製した。得られたＣＮＴを遠心分離し、さらにフィルタを介して分画することにより、平均長さが異なる複数のＣＮＴサンプルを作製した。分画した複数のＣＮＴサンプルの平均長さをそれぞれ測定した。このように長さが調整された複数のＣＮＴサンプル２５ｍｇを、５ｍｌの水と、分散剤として含有量を変化させたコール酸ナトリウム（富士フィルム和光純薬社製）が溶解されている溶液に加え、超音波分散機（「ＮＲ−５０Ｍ」 マイクロテック・ニチオン社製）により、２５（室温）℃で１時間分散処理をし、ＣＮＴ分散液を作製した。作製したＣＮＴ分散液をテフロン（登録商標）板上に数滴滴下し、バーコーターを用いて所定の塗布速度でＣＮＴ分散液を塗布し、塗布膜を形成した。得られた塗布膜を２５℃で１時間自然乾燥させて半乾きの状態にした後、乾燥した塗布膜の淵をピンセットで剥がして、ピンセットを用いて塗布膜をロール状に巻き、さらに、一晩自然乾燥させることにより、ＣＮＴ線材を作製した。各実施例及び各比較例における分散剤の含有量、複数のＣＮＴサンプルの平均長さ（ＣＮＴの平均長さ）及び塗布速度を表１に示す。尚、表１中、このような製法をロール糸と表記する。
[About Examples 1-12 and Comparative Examples 1 and 5-7]
CNTs were prepared by the floating catalyst method. The obtained CNTs were centrifuged and further fractionated through a filter to prepare a plurality of CNT samples having different average lengths. The average lengths of the plurality of fractionated CNT samples were measured. A plurality of 25 mg of CNT samples whose lengths have been adjusted in this manner are added to a solution in which 5 ml of water and sodium cholic acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) having a varied content as a dispersant are dissolved. , An ultrasonic disperser (“NR-50M” manufactured by Microtech Nithion Co., Ltd.) was used for dispersion treatment at 25 (room temperature) ° C. for 1 hour to prepare a CNT dispersion solution. A few drops of the prepared CNT dispersion were dropped onto a Teflon (registered trademark) plate, and the CNT dispersion was applied at a predetermined coating rate using a bar coater to form a coating film. The obtained coating film is naturally dried at 25 ° C. for 1 hour to make it semi-dry, then the edge of the dried coating film is peeled off with tweezers, and the coating film is rolled into a roll using tweezers. The CNT wire was prepared by air-drying at night. Table 1 shows the content of the dispersant, the average length of the plurality of CNT samples (average length of CNTs), and the coating rate in each Example and each Comparative Example. In Table 1, such a manufacturing method is referred to as a roll yarn.
［比較例２〜４］
比較例２〜４では、上記のような工程を経て作製したＣＮＴ分散液をシリンジに入れ、０．１ｍｌ／分の吐出速度でイソプロパノールの凝固液（富士フィルム和光純薬社製）に吐出し、ＣＮＴが凝固するまで数分放置し、糸状のＣＮＴ紡糸線を作製した。その後、得られた糸状のＣＮＴ紡糸線を取り出し、一晩自然乾燥させることにより、ＣＮＴ線材を作製した。複数のＣＮＴサンプルの平均長さは、上記の実施例１〜１２及び比較例１、５〜７と同様にそれぞれ測定した。比較例２〜４における分散剤の含有量及び複数のＣＮＴサンプルの平均長さ（ＣＮＴの平均長さ）を表１に示す。尚、表１中、このような製法を湿
式紡糸と表記する。
[Comparative Examples 2 to 4]
In Comparative Examples 2 to 4, the CNT dispersion liquid prepared through the above steps was put into a syringe and discharged into a coagulating liquid of isopropanol (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) at a discharge rate of 0.1 ml / min. It was left for several minutes until the CNT solidified to prepare a thread-like CNT spun wire. Then, the obtained filamentous CNT spun wire was taken out and air-dried overnight to prepare a CNT wire. The average lengths of the plurality of CNT samples were measured in the same manner as in Examples 1 to 12 and Comparative Examples 1 and 5 to 7, respectively. Table 1 shows the content of the dispersant in Comparative Examples 2 to 4 and the average length of a plurality of CNT samples (average length of CNT). In Table 1, such a manufacturing method is referred to as wet spinning.
＜測定項目＞
［ＣＮＴの平均長さ］
実施例１〜１２および比較例１〜６で使用したＣＮＴの平均長さは、ＣＮＴ分散液中に存在するＣＮＴを、ＳＥＭ（走査型電子顕微鏡）を用いてＳＥＭ画像から算出した。具体的には、倍率が１００００倍であるＳＥＭ画像に存在する任意のＣＮＴの長さを測定した。これを別のＣＮＴでも同様に行い、２００本のＣＮＴの長さの平均値を平均長さとして算出した。尚、ＣＮＴ分散液中に存在するＣＮＴの平均長さとＣＮＴ線材に存在するＣＮＴの平均長さは、紡糸の影響を受けないため同等であると評価した。
<Measurement item>
[Average length of CNT]
The average length of the CNTs used in Examples 1 to 12 and Comparative Examples 1 to 6 was calculated from the SEM image of the CNTs present in the CNT dispersion liquid using an SEM (scanning electron microscope). Specifically, the length of any CNT present in the SEM image having a magnification of 10000 times was measured. This was done in the same manner for another CNT, and the average value of the lengths of 200 CNTs was calculated as the average length. The average length of CNTs present in the CNT dispersion liquid and the average length of CNTs present in the CNT wire rod were evaluated to be equivalent because they were not affected by spinning.
［密度］
ＣＮＴ線材の密度を測定した。具体的には、超高速・高精度寸法測定器（ＫＥＹＥＮＣＥ社製）を用いてＣＮＴ線材の素線径を測定し、さらに、ノギスでＣＮＴ線材の長さを測定してＣＮＴ線材の体積を計算した。得られた体積の値と、分析てんびん（「ＸＰ６」 ＭＥＴＴＬＥＲ ＴＯＬＥＤＯ社製）で測定したＣＮＴ線材の重さからＣＮＴ線材の密度を算出した。
[density]
The density of the CNT wire was measured. Specifically, the wire diameter of the CNT wire is measured using an ultra-high-speed, high-precision dimensional measuring device (manufactured by KEYENCE), and the length of the CNT wire is measured with a caliper to calculate the volume of the CNT wire. did. The density of the CNT wire was calculated from the value of the obtained volume and the weight of the CNT wire measured with an analytical balance (“XP6” manufactured by METTLER TOLEDO).
［Ｇ／Ｄ比］
ラマン分光装置（Thermo Fisher Scientific社製、「ＡＬＭＥＧＡ ＸＲ」）により、励起レーザ：５３２ｎｍ、レーザ強度：１０％に減光、対物レンズ：５０倍、露光時間：1秒×６０回の条件にて測定し、ラマンスペクトルを得た。次に、スペクトル解析ソフト
ウェア（日本分光社製、「Spectra Manager」）により、ラマンスペクトルの１０００〜
２０００ｃｍ−１のデータを切り出し、この範囲で検出されるピーク群をCurve Fitting
により分離解析を行った。尚、ベースラインは１０００ｃｍ−１と２０００ｃｍ−１での検出強度を結んだ線とする。このように切り出したラマンスペクトルにおいて、ＧバンドとＤバンドそれぞれのピークトップ高さ（ピークトップからベースラインの値を差し引いた検出強度）を求め、その値からＧ／Ｄ比の値を算出した。
[G / D ratio]
Measured with a Raman spectrometer ("ALMEGA XR" manufactured by Thermo Fisher Scientific) under the conditions of excitation laser: 532 nm, laser intensity: dimmed to 10%, objective lens: 50 times, exposure time: 1 second x 60 times. Then, a Raman spectrum was obtained. Next, using spectrum analysis software (manufactured by JASCO Corporation, "Spectra Manager"), Raman spectra of 1000 to
Data of 2000 cm -1 is cut out, and the peak group detected in this range is Curve Fitting.
Separation analysis was performed by. The baseline is a line connecting the detection intensities at 1000 cm -1 and 2000 cm -1 . In the Raman spectrum cut out in this way, the peak top heights (detection intensity obtained by subtracting the baseline value from the peak top) of each of the G band and the D band were obtained, and the G / D ratio value was calculated from the values.
［配向性］
ＣＮＴ線材の円相当半径をＲ、同心円でＲ／√２の半径を有する部分の範囲をＣＮＴ線材の内側、同心円でＲ−（Ｒ／√２）の厚さを有する中空円部分の範囲をＣＮＴ線材の外側として定め、ＣＮＴ線材の外側におけるヘルマンの配向係数（外側の配向係数）とＣＮＴ線材の内側におけるヘルマンの配向係数（内側の配向係数）をそれぞれ測定した。外側の配向係数及び内側の配向係数は、イオンミリングを用いてＣＮＴ線材を長軸方向に沿って切断し、その切断面をＳＥＭ（走査型電子顕微鏡）で観察し、当該切断面におけるＳＥＭ画像をＦＦＴ（高速フーリエ変換）処理して配向解析を行うことで算出した。さらに、外側の配向係数と内側の配向係数との差の絶対値（配向係数の内外差）を算出した。
[Orientation]
The equivalent radius of the circle of the CNT wire is R, the range of the concentric circle with a radius of R / √2 is the inside of the CNT wire, and the range of the concentric circle with a thickness of R- (R / √2) is CNT. It was defined as the outside of the wire, and the Hermann's orientation coefficient on the outside of the CNT wire (outer orientation coefficient) and the Hermann's orientation coefficient on the inside of the CNT wire (inner orientation coefficient) were measured. For the outer orientation coefficient and the inner orientation coefficient, the CNT wire is cut along the long axis using ion milling, the cut surface is observed with an SEM (scanning electron microscope), and the SEM image on the cut surface is obtained. It was calculated by performing FFT (Fast Fourier Transform) processing and orientation analysis. Furthermore, the absolute value of the difference between the outer orientation coefficient and the inner orientation coefficient (inner / outer difference of the orientation coefficient) was calculated.
＜評価項目＞
上記のようにして作製したＣＮＴ線材について、以下の評価を行った。
<Evaluation items>
The CNT wire rods produced as described above were evaluated as follows.
［空隙率］
イオンミリングを用いてＣＮＴ線材の任意の箇所で径方向に沿って切断し、その切断面をＳＥＭ（走査型電子顕微鏡）で観察し、当該切断面におけるＳＥＭ画像を解析し、切断面内に存在する全空隙の面積の合計を測定した。すなわち、空隙率は、以下の式により算出される。
[Void ratio]
Cut along the radial direction at any point on the CNT wire using ion milling, observe the cut surface with a SEM (scanning electron microscope), analyze the SEM image on the cut surface, and exist in the cut surface. The total area of all voids was measured. That is, the void ratio is calculated by the following formula.
空隙率［％］＝（全空隙の面積の和／ＣＮＴ線材の断面積）×１００ Void ratio [%] = (sum of total void areas / cross-sectional area of CNT wire) x 100
［空隙の分散度］
上記の空隙率の測定法で、任意に５箇所の切断面に対する空隙率をそれぞれ測定し、その標準偏差を算出した。空隙の分散度が５．０以下であれば、ＣＮＴ線材の外側と内側とで局所的に大きな空隙はほとんどなく、配向ムラが抑制されていると評価した。
[Dispersity of voids]
By the above-mentioned measuring method of void ratio, the void ratio with respect to the cut surface at five points was arbitrarily measured, and the standard deviation thereof was calculated. When the degree of dispersion of the voids was 5.0 or less, it was evaluated that there were almost no large voids locally on the outside and the inside of the CNT wire, and the uneven orientation was suppressed.
［導電性］
ＣＮＴ線材の導電性の評価として、四端子法により体積抵抗率を測定した。具体的には、抵抗測定機にＣＮＴ線材を接続し、四端子法により抵抗測定を実施した。体積抵抗率ｒは、ｒ＝ＲＡ／Ｌ（Ｒ：抵抗、Ａ：ＣＮＴ線材の断面積、Ｌ：測定長さ）の計算式に基づいて算出した。体積抵抗率が１．０×１０−５Ω・ｃｍ未満の場合を「◎」、１．０×１０−５Ω・ｃｍ以上４．０×１０−５Ω・ｃｍ未満の場合を「○」、４．０×１０−５Ω・ｃｍ以上８．０×１０−５Ω・ｃｍ未満の場合を「△」、８．０×１０−５Ω・ｃｍ以上の場合を「×」と評価し、「△」以上であれば、導電性に優れていると評価した。
[Conductivity]
As an evaluation of the conductivity of the CNT wire, the volume resistivity was measured by the four-terminal method. Specifically, the CNT wire was connected to the resistance measuring machine, and the resistance was measured by the four-terminal method. The volume resistivity r was calculated based on the formula of r = RA / L (R: resistance, A: cross-sectional area of CNT wire, L: measurement length). The case where the volume resistivity is less than 1.0 × 10 -5 Ω · cm "◎", the case of less than 1.0 × 10 -5 Ω · cm or more 4.0 × 10 -5 Ω · cm "○" , in the case of less than 4.0 × 10 -5 Ω · cm or more 8.0 × 10 -5 Ω · cm "△", the case of more than 8.0 × 10 -5 Ω · cm was evaluated as "×" , “Δ” or more, it was evaluated as having excellent conductivity.
［強度］
ＣＮＴ線材の強度の評価として、引張強度を測定した。具体的には、ＣＮＴ線材の引張強度を万能試験機の引張試験により測定した。ロードセルは１００Ｎとし、試験速度は６ｍｍ/ｍｉｎで測定した。マイクロスコープで観察し得たＣＮＴ線材の直径から断面積を
求めた。引張強度ｓは、ｓ＝Ｆ／Ａ（Ｆ：試験力、Ａ：ＣＮＴ線材の断面積）の計算式に基づいて算出した。引張強度が２００ＭＰａ以上の場合を「◎」、１５０ＭＰａ以上２００ＭＰａ未満の場合を「○」、１００ＭＰａ以上１５０ＭＰａ未満の場合を「△」、１００ＭＰａ未満の場合を「×」と評価し、「△」以上であれば、強度に優れていると評価した。
[Strength]
Tensile strength was measured as an evaluation of the strength of the CNT wire. Specifically, the tensile strength of the CNT wire was measured by a tensile test of a universal testing machine. The load cell was 100 N, and the test speed was measured at 6 mm / min. The cross-sectional area was determined from the diameter of the CNT wire rod that could be observed with a microscope. The tensile strength s was calculated based on the formula of s = F / A (F: test force, A: cross-sectional area of CNT wire). When the tensile strength is 200 MPa or more, it is evaluated as "◎", when it is 150 MPa or more and less than 200 MPa, it is evaluated as "○", when it is 100 MPa or more and less than 150 MPa, it is evaluated as "△", and when it is less than 100 MPa, it is evaluated as "×". If so, it was evaluated as having excellent strength.
ＣＮＴ線材の測定および評価結果について、下記表１に示す。 The measurement and evaluation results of the CNT wire rod are shown in Table 1 below.
表１に示すように、平均長さが１５μｍ以上のＣＮＴを含む実施例１〜１２で作製したＣＮＴ線材は、いずれも外側の配向係数が高く、また、配向係数の内外差も低い値を示した。また、空隙率も少なく、空隙の分散度も５．０以下であるため、ＣＮＴ線材の外側と内側とで局所的に大きな空隙はほとんどなく、配向ムラも抑制されていた。そのため、得られたＣＮＴ線材は、平均長さが１５μｍ以上の比較的長いＣＮＴを含みつつ、配向性、導電性及び強度に優れていた。特に、密度が１．４ｇ／ｃｍ３以上である実施例７、１０においては、顕著に高い強度を示した。 As shown in Table 1, the CNT wires produced in Examples 1 to 12 containing CNTs having an average length of 15 μm or more all have a high outer orientation coefficient and a low inner-outer difference of the orientation coefficient. It was. Further, since the void ratio was small and the degree of dispersion of the voids was 5.0 or less, there were almost no large voids locally on the outside and inside of the CNT wire, and uneven orientation was suppressed. Therefore, the obtained CNT wire rod was excellent in orientation, conductivity and strength while containing a relatively long CNT having an average length of 15 μm or more. In particular, in Examples 7 and 10 having a density of 1.4 g / cm 3 or more, the strength was remarkably high.
一方、比較例１では、ＣＮＴの平均長さが１５μｍ未満であり、長いＣＮＴが少な過ぎるため優れた導電性が得られなかった。また、長いＣＮＴ同士の繋がりが少ないため、優れた強度も得られなかった。 On the other hand, in Comparative Example 1, the average length of CNTs was less than 15 μm, and the number of long CNTs was too small, so that excellent conductivity could not be obtained. In addition, since there are few connections between long CNTs, excellent strength cannot be obtained.
従来の湿式紡糸によりＣＮＴ線材を作製した比較例２〜４では、配向係数の内外差及び空隙率が顕著に高いため、配向ムラが顕著であり、導電性及び強度が劣っていた。 In Comparative Examples 2 to 4 in which the CNT wire rod was produced by conventional wet spinning, the difference between the inside and outside of the orientation coefficient and the void ratio were remarkably high, so that the orientation unevenness was remarkable and the conductivity and strength were inferior.
比較例５、６では、外側の配向係数が小さく、平均長さが１５μｍ以上のＣＮＴの配向性が低いため、ＣＮＴ線材に高い導電性を付与することができなかった。 In Comparative Examples 5 and 6, high conductivity could not be imparted to the CNT wire rod because the outer orientation coefficient was small and the orientation of the CNTs having an average length of 15 μm or more was low.
比較例７では、Ｇ／Ｄ比が低いため、欠陥が多く、導電性及び強度が劣っていた。 In Comparative Example 7, since the G / D ratio was low, there were many defects, and the conductivity and strength were inferior.
１０ カーボンナノチューブ線材
１１ カーボンナノチューブ集合体
１１ａ カーボンナノチューブ
２０ 内側
３０ 外側
10 Carbon Nanotube Wire 11 Carbon Nanotube Aggregate 11a Carbon Nanotube 20 Inside 30 Outside
Claims (6)
前記複数のカーボンナノチューブの平均長さが１５μｍ以上であり、
前記カーボンナノチューブ線材において、前記カーボンナノチューブ線材の円相当半径をＲ、同心円でＲ／√２の半径を有する部分の範囲をカーボンナノチューブ線材の内側、同心円で前記カーボンナノチューブ線材の内側を除いた部分の範囲をカーボンナノチューブ線材の外側としたとき、走査型電子顕微鏡で観察し得られた画像を高速フーリエ変換した画像を解析し算出されるヘルマンの配向係数が、前記カーボンナノチューブ線材の外側で０．７５以上であり、且つ前記カーボンナノチューブ線材の外側におけるヘルマンの配向係数と前記カーボンナノチューブ線材の内側におけるヘルマンの配向係数との差の絶対値が０．０５以下であり、かつ
前記カーボンナノチューブ線材におけるラマンスペクトルのＧバンドに対する結晶性に由来するＤバンドの比であるＧ／Ｄ比が７０以上であることを特徴とするカーボンナノチューブ線材。 It is a carbon nanotube wire rod composed of a carbon nanotube aggregate composed of a plurality of carbon nanotubes.
The average length of the plurality of carbon nanotubes is 15 μm or more, and the average length is 15 μm or more.
In the carbon nanotube wire rod, the circle-equivalent radius of the carbon nanotube wire rod is R, the range of the portion having a radius of R / √2 in the concentric circle is the inside of the carbon nanotube wire rod, and the portion of the concentric circle excluding the inside of the carbon nanotube wire rod. When the range is outside the carbon nanotube wire, the Hermann orientation coefficient calculated by analyzing the image obtained by high-speed Fourier conversion of the image obtained by the scanning electron microscope is 0.75 outside the carbon nanotube wire. The absolute value of the difference between the orientation coefficient of Hermann on the outside of the carbon nanotube wire and the orientation coefficient of Hermann on the inside of the carbon nanotube wire is 0.05 or less, and the Raman spectrum of the carbon nanotube wire. A carbon nanotube wire rod having a G / D ratio of 70 or more, which is the ratio of the D band derived from the crystallinity to the G band.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006027961A (en) * | 2004-07-16 | 2006-02-02 | Univ Of Tokyo | Carbon nanotube dispersion film and light emitting body |
| JP2009292664A (en) * | 2008-06-03 | 2009-12-17 | Sony Corp | Method and apparatus for producing thin film and method for manufacturing electronic device |
| WO2010076885A1 (en) * | 2008-12-30 | 2010-07-08 | 独立行政法人産業技術総合研究所 | Aligned single-walled carbon nanotube assembly, bulk aligned single-walled carbon nanotube assembly, powder-like aligned single-walled carbon nanotube assembly, and method for producing same |
| WO2015083701A1 (en) * | 2013-12-03 | 2015-06-11 | 国立大学法人静岡大学 | Carbon nanotube twisted yarn, and production method and spinning source for carbon nanotube twisted yarn |
| JP2017171546A (en) * | 2016-03-24 | 2017-09-28 | 古河電気工業株式会社 | Carbon nanotube wire and carbon nanotube wire-connected structure |
| WO2018143466A1 (en) * | 2017-02-03 | 2018-08-09 | 古河電気工業株式会社 | Carbon nanotube wire material, method for manufacturing carbon nanotube, and method for manufacturing carbon nanotube wire material |
-
2019
- 2019-03-29 JP JP2019068765A patent/JP7316822B2/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006027961A (en) * | 2004-07-16 | 2006-02-02 | Univ Of Tokyo | Carbon nanotube dispersion film and light emitting body |
| JP2009292664A (en) * | 2008-06-03 | 2009-12-17 | Sony Corp | Method and apparatus for producing thin film and method for manufacturing electronic device |
| WO2010076885A1 (en) * | 2008-12-30 | 2010-07-08 | 独立行政法人産業技術総合研究所 | Aligned single-walled carbon nanotube assembly, bulk aligned single-walled carbon nanotube assembly, powder-like aligned single-walled carbon nanotube assembly, and method for producing same |
| WO2015083701A1 (en) * | 2013-12-03 | 2015-06-11 | 国立大学法人静岡大学 | Carbon nanotube twisted yarn, and production method and spinning source for carbon nanotube twisted yarn |
| JP2017171546A (en) * | 2016-03-24 | 2017-09-28 | 古河電気工業株式会社 | Carbon nanotube wire and carbon nanotube wire-connected structure |
| WO2018143466A1 (en) * | 2017-02-03 | 2018-08-09 | 古河電気工業株式会社 | Carbon nanotube wire material, method for manufacturing carbon nanotube, and method for manufacturing carbon nanotube wire material |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021044963A1 (en) * | 2019-09-03 | 2021-03-11 | 住友電気工業株式会社 | Carbon nanotube-resin composite body and method for producing carbon nanotube-resin composite body |
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