Method and apparatus for manufacturing carbon nanotube coated materials

Abstract

To provide a novel method and apparatus for manufacturing carbon nanotube coated articles, which involves coating articles with carbon nanotube fibers. [Solution] A method for manufacturing a carbon nanotube coated object, comprising: a first step of preparing an article and a carbon nanotube forest; and a second step of attaching carbon nanotube fibers or bundles drawn from the carbon nanotube forest to the surface of the article, and then rotating the carbon nanotube forest around the article to coat the surface of the article with the carbon nanotube fibers or bundles.

Description

Technical Field

[0001] The present disclosure relates to a method and an apparatus for manufacturing a carbon nanotube coating.

Background Art

[0002] From the viewpoints of heat resistance and mechanical properties, etc., an article having its surface coated with carbon nanotubes may be used (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a novel method and an apparatus for manufacturing a carbon nanotube coating that coats an article with carbon nanotube fibers.

Means for Solving the Problems

[0005] One aspect of the method for manufacturing a carbon nanotube coating of the present disclosure includes a first step of preparing an article and a carbon nanotube forest, and a second step of attaching carbon nanotube fibers or a bundle thereof drawn from the carbon nanotube forest to the surface of the article, and then rotating the carbon nanotube forest around the article to coat the surface of the article with the carbon nanotube fibers or the bundle thereof.

[0006] One embodiment of the apparatus for manufacturing a carbon nanotube coated article according to the present disclosure comprises a rotatable, hollow rotating member, a carbon nanotube substrate mounted on the rotating member, and a moving device for moving an article to be coated with carbon nanotube fibers relative to the rotating member in the direction of the rotation axis. The carbon nanotube substrate has a substrate and a carbon nanotube forest on the substrate. In the manufacturing apparatus, the carbon nanotube forest is rotated around an article moving relative to the article in the inner space of the rotating member by rotating the rotating member, thereby coating the surface of the article with carbon nanotube fibers. [Effects of the Invention]

[0007] According to this disclosure, a novel method and apparatus for manufacturing carbon nanotube coated articles, in which an article is coated with carbon nanotube fibers, can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a top view of a carbon nanotube forest and a carbon nanotube web illustrating a method for manufacturing carbon nanotube webs. [Figure 2] Figure 2 is a cross-sectional view along line AA in Figure 1. [Figure 3A] Figure 3A is a schematic diagram illustrating a method for coating an object with carbon nanotube fibers. [Figure 3B] Figure 3B is a schematic diagram illustrating a method for coating an object with carbon nanotube fibers. [Figure 3C] Figure 3C is a schematic diagram illustrating a method for coating an object with carbon nanotube fibers. [Figure 4A] Figure 4A is a schematic diagram illustrating a method for coating an article with carbon nanotube fibers using a tubular member. [Figure 4B] Figure 4B is a schematic diagram illustrating a method for coating an article with carbon nanotube fibers using a ring-shaped member. [Figure 5A] Figure 5A is a schematic diagram illustrating the orientation angle in a carbon nanotube fiber layer. [Figure 5B] Figure 5B is a schematic diagram illustrating the orientation angle, the distance between the centerlines of the bundles, the width of the bundles, and the spacing between the bundles in a bundle of carbon nanotube fibers that covers an article. [Figure 6A] Figure 6A is a schematic diagram illustrating the apparatus for manufacturing carbon nanotube-coated materials. [Figure 6B] Figure 6B is a schematic diagram illustrating the manufacturing apparatus for carbon nanotube-coated materials. [Figure 7] Figure 7 is a schematic diagram illustrating a carbon nanotube coating manufacturing apparatus equipped with a control device. [Modes for carrying out the invention]

[0009] An example of an embodiment of this disclosure will be described in detail below with reference to the drawings. Note that, for convenience, the drawings used in the following description may show enlarged versions of key features to make the features of this disclosure easier to understand. Therefore, the dimensional ratios of each component may differ from those of the actual components.

[0010] In this specification, the numerical range A to B means A or greater and B or less. In this specification, if the units of the numbers before and after the "~" indicating a numerical range are the same, the unit of the number before the "~" may be omitted.

[0011] In the following explanation, the terms "film" and "sheet" are not clearly distinguished; the term "film" may include "sheet," and vice versa.

[0012] As used herein, "parallel" includes not only exact parallelism but also approximate parallelism. Regarding parallelism, the angle formed between them may be, for example, 30° or less, 20° or less, 10° or less, or 5° or less. As used herein, "perpendicular" includes not only exact perpendicularity but also approximate perpendicularity, and "orthogonal" includes not only exact orthogonality but also approximate orthogonality. Regarding perpendicularity and orthogonality, the angle formed between them may be, for example, 60° or more and 90° or less, 70° or more and 90° or less, 80° or more and 90° or less, or 85° or more and 90° or less.

[0013] Hereinafter, carbon nanotubes are also referred to as "CNT", fibers composed of carbon nanotubes directly drawn from a carbon nanotube forest are also referred to as "CNT fibers", and web-like bodies of carbon nanotubes are also referred to as "CNT web-like bodies".

[0014] [Method for manufacturing carbon nanotube coating] The method for manufacturing the carbon nanotube coating (CNT coating) of the present disclosure is a first step of preparing an article and a carbon nanotube forest, and a second step of attaching carbon nanotube fibers or a bundle thereof drawn from the carbon nanotube forest to the surface of the article, and then rotating the carbon nanotube forest around the article to coat the surface of the article with the carbon nanotube fibers or the bundle thereof. <The first step> The first step is a step of preparing an article and a carbon nanotube forest (CNT forest).

[0015] Examples of article shapes include linear, strip-shaped, plate-shaped, polyhedral, polygonal prism-shaped, cylindrical, polygonal pyramidal, conical, frustum-shaped, spherical, ellipsoidal, and biconical shapes. Examples of linear shapes include rod-shaped, string-shaped, tubular, and cylindrical shapes. Examples of polyhedral shapes include cubic and rectangular prism shapes. Examples of polygonal prism shapes include triangular and square prism shapes. Examples of polygonal pyramidal shapes include triangular and square pyramidal shapes. Examples of polygonal frustum-shaped shapes include square frustum shapes. An article may have both flat and curved surfaces. An article may be curved or not.

[0016] For example, if the shape of the item is linear, strip-shaped, or plate-shaped, the length of the item may be 10 cm to 10 km, 1 m to 1 km, or 1 to 200 m. The length of the item refers to the size of the item in the direction of the rotation axis of the CNT forest, which will be described later.

[0017] For example, if the shape of the article is strip-shaped or plate-shaped, the thickness of the article may be 1 μm to 1 m, 10 μm to 1 m, or 100 μm to 1 m. The thickness of the article refers to the length of the longest side of the article in a cross-section perpendicular to the length direction.

[0018] For example, if the shape of an article is linear, the thickness of the article may be 1 μm to 1 m, 10 μm to 50 cm, 70 μm to 10 cm, 80 μm to 1 cm, or 90 μm to 10 mm. The thickness of an article with a linear shape refers to the maximum distance between two parallel lines when the cross-section of the article is sandwiched between them.

[0019] For example, if the shape of the object is spherical, the diameter of the object may be 1 μm to 1 m, 10 μm to 1 m, or 100 μm to 1 m. The thickness, diameter, and other properties of an object are measured by observing a cross-section perpendicular to the length direction using a scanning electron microscope (SEM) or optical microscope, or by using calipers.

[0020] Examples of materials that make up an article include natural resins, synthetic resins, metals, glass, and paper. The article may be made up of one type of material or two or more types of materials.

[0021] The article is preferably linear in shape, from the viewpoint that the CNT fiber layer described later is dense and has excellent adhesion to the article. A linear article refers to an article having a linear shape. A linear article may be straight or curved. Examples of cross-sectional shapes of a linear article include circular, elliptical, rectangular, and polygonal shapes. Examples of linear materials include optical fibers, fibers, threads, metal wires, electric wires, wire harnesses, and tubes. Examples of optical fibers include glass optical fibers and plastic optical fibers. Examples of metal wires include aluminum wires, gold wires, silver wires, copper wires, stainless steel wires, and zinc wires. The linear object is preferably an optical fiber, and more preferably a glass optical fiber. If the linear object is an optical fiber, one preferred embodiment is that the optical fiber is not coated on the surface with resin.

[0022] In the first step, you may prepare one item or multiple items.

[0023] A CNT forest refers to an aggregate of multiple carbon nanotubes (CNTs) arranged on a substrate and oriented perpendicular to the surface of the substrate. In a CNT forest, multiple CNTs stand upright on the substrate. In the first step, a carbon nanotube substrate (CNT substrate) may be prepared, comprising a substrate and a CNT forest provided on the substrate. The CNT substrate may also be obtained by transferring a CNT forest from a catalyst substrate (described later) to another substrate.

[0024] A CNT forest can be obtained, for example, by performing chemical vapor deposition (CVD) on a catalyst substrate comprising a substrate and a catalyst layer provided on the substrate. The CVD method involves placing the catalyst substrate in a reaction chamber, supplying a raw material gas to the reaction chamber, and growing CNTs on the surface of the catalyst layer. Thermal CVD is preferred as the CVD method.

[0025] Examples of substrates include silicon substrates, alumina substrates, magnesium oxide substrates, glass substrates, sapphire substrates, and stainless steel substrates.

[0026] The catalyst layer can be formed, for example, by attaching catalyst particles to the substrate by sputtering. Examples of catalysts include metals, specifically iron (Fe), nickel (Ni), cobalt (Co), molybdenum (Mo), gold (Au), and alloys containing at least one metal selected from the group consisting of these. Examples of alloys include iron alloys, nickel alloys, and cobalt alloys. The catalyst may also be a metal precursor, such as a metal oxide or metal compound. Examples of metal oxides include iron oxide, nickel oxide, and cobalt oxide. An example of a metal compound is iron chloride. When using a precursor, it is necessary to convert the precursor to a metal before performing the CVD method, for example, by heating it.

[0027] The catalyst substrate described above may further include a buffer layer between the substrate and the catalyst layer. Examples of materials used for the buffer layer include silica (SiO2), alumina (Al2O3), silicon nitride (SiN), zinc oxide (ZnO), copper oxide (Cu2O), and nickel oxide (NiO). The buffer layer can be formed, for example, by sputtering.

[0028] Sputtering for forming the catalyst layer and sputtering for forming the buffer layer can be carried out using known apparatus and conditions depending on the object to be sputtered. The pressure conditions for sputtering are preferably 0.01 to 10 Pa, more preferably 0.1 to 1 Pa.

[0029] As the raw material gas, carbon-containing raw material gases can be used, such as hydrocarbons, sulfur-containing organic gases, phosphorus-containing organic gases, carbon monoxide, and alcohols. Examples of hydrocarbons include alkane compounds such as methane and ethane, alkene compounds such as ethylene and butadiene, alkyne compounds such as acetylene, aryl hydrocarbon compounds such as benzene, toluene, and styrene, aromatic hydrocarbons having condensed rings such as indene, naphthalene, and phenanthrene, cycloalkane compounds such as cyclopropane and cyclohexane, cycloolefin compounds such as cyclopentene, and alicyclic hydrocarbon compounds having condensed rings such as steroids. Examples of alcohols include methanol and ethanol. From the viewpoint of the carbon purity of the resulting CNTs, the raw material gas is preferably hydrocarbons.

[0030] Along with the raw material gas, a carrier gas, which is a gas that transports the raw material gas, may also be supplied to the reaction chamber. Examples of carrier gases include helium, neon, argon, nitrogen, and hydrogen.

[0031] In the CVD method, the temperature in the reaction chamber is preferably 600-850°C, more preferably 650-800°C, from the viewpoint of the growth rate of CNTs and the carbon purity of the resulting CNTs. In the CVD method, the pressure inside the reaction chamber is preferably atmospheric pressure from the viewpoint of the growth rate of CNTs and carbon purity. Depending on other conditions when carrying out the CVD method, the pressure inside the reaction chamber may be reduced or increased from atmospheric pressure.

[0032] The average length of CNTs in the CNT forest is preferably 10 to 1000 μm, more preferably 30 to 800 μm, and even more preferably 50 to 500 μm. The average length of CNTs can be adjusted, for example, by adjusting the time spent on the CVD method, i.e., the CNT growth time. The average diameter of the CNTs in the CNT forest is preferably 1 to 50 nm, more preferably 3 to 30 nm, and even more preferably 5 to 15 nm. The average diameter of the CNTs can be adjusted, for example, by adjusting the thickness of the catalyst layer and the type of catalyst, as described later.

[0033] The average length and average diameter of carbon nanotubes (CNTs) are measured using a scanning electron microscope (SEM) or a transmission electron microscope (TEM). Specifically, 10 images of the CNTs are obtained using an SEM or TEM. For each of the 10 images, 10 arbitrary measurement points are selected and measured, totaling 100 lengths. The average length of the CNTs is then calculated by arithmetic mean of these 100 length measurements. Similarly, for each of the 10 images, 10 arbitrary measurement points are selected and measured, totaling 100 diameters. The average diameter of the CNTs is then calculated by arithmetic mean of these 100 diameter measurements.

[0034] The carbon purity of CNTs obtained from a CNT forest is preferably 95.0 to 99.999%. The lower limit of the carbon purity of CNTs is preferably 96.0%, more preferably 97.0%, even more preferably 98.0%, even more preferably 99.0%, and particularly preferably 99.8%. The upper limit of the carbon purity of CNTs may be, for example, 99.99% or 99.9%. The carbon purity of CNTs can be determined, for example, by elemental analysis using X-ray fluorescence.

[0035] The crystallinity of carbon nanotubes (CNTs) obtained from a CNT forest can be evaluated, for example, using Raman spectroscopy. In Raman spectroscopy, the D / G ratio is used as an indicator for evaluating crystallinity. The D / G ratio is the value at 1580 cm⁻¹ in the Raman spectrum measured by Raman spectroscopy. -1 1360 cm⁻¹ relative to the peak intensity of the G-band appearing in the vicinity-1 This is the ratio of the peak intensities of the D-band that appear in the vicinity. A smaller D / G ratio indicates higher crystallinity of the carbon nanotube. The D / G ratio in CNTs is preferably 0.5 to 1.0, more preferably 0.6 to 0.8.

[0036] The carbon purity and crystallinity of CNTs can be adjusted, for example, by controlling the thickness of the buffer layer in the catalyst substrate, the type of material used for the buffer layer, the thickness of the catalyst layer, the type of catalyst, the type and flow rate of the raw material gas in the CVD method, and the temperature and pressure in the reaction chamber.

[0037] The carbon nanotubes (CNTs) obtained from the CNT forest may be single-walled carbon nanotubes or multi-walled carbon nanotubes with two or more layers. Multi-walled carbon nanotubes are preferred. The number of layers in the multi-walled carbon nanotube is not particularly limited, but is preferably 2 to 20.

[0038] In the first step, you may prepare one or more CNT forests. In the first step, the articles and CNT forest may be prepared by manufacturing them, or the articles and CNT forest may be prepared from already manufactured articles. For example, if the item is an optical fiber, commercially available optical fibers with a surface coating of resin or the like may be provided, or optical fibers without a surface coating may be provided. Commercially available optical fibers with a surface coating of resin or the like may have the surface coating removed and then be provided as optical fibers.

[0039] In the first step, a rotatable member may be provided. The rotation of the rotatable member may be performed around a single axis of rotation. The rotatable member may have a hollow space inside the member that extends parallel to the axis of rotation, through which an article can pass in the direction of the axis of rotation. Examples of rotatable members include cylindrical members and ring-shaped members. When preparing a rotating component, one rotating component may be used, or multiple rotating components may be used.

[0040] <Second process> The second step involves attaching the CNT fibers or bundles drawn from the CNT forest to the surface of the article, and then rotating the CNT forest around the article to coat the surface of the article with the CNT fibers or bundles. Because CNT fibers extracted from CNT forests maintain high surface energy, they can adhere to objects without the need for adhesives or other materials.

[0041] CNT fibers refer to fibers containing multiple carbon nanotubes (CNTs). CNT fibers are composed of multiple CNTs oriented in one direction. In CNT fibers, the longitudinal directions of the multiple CNTs are aligned in one direction. The CNTs contained in the CNT fibers are obtained from the CNT forest prepared in the first step. In the second step, a linear body obtained by bundling CNT webs, which are manufactured by drawing multiple CNT fibers from a CNT forest into a sheet, or a twisted yarn obtained by twisting the linear body, may be attached to the surface of an article. Examples of bundles of CNT fibers include the linear body and the twisted yarn.

[0042] A CNT web refers to a web containing multiple carbon nanotube (CNT) fibers. A CNT web may be, for example, an aggregate of multiple CNT fibers arranged in a planar direction when viewed from above. "Viewing a CNT web from above" means viewing a planar CNT web from the direction of its normal vector.

[0043] CNT fibers or CNT webs can be manufactured, for example, by extracting CNTs located at the ends of a CNT forest using a gripping tool such as tweezers, so that they are separated from the CNT forest in a direction parallel to the surface of the substrate on which the CNT forest is provided. When CNTs located at the ends of a CNT forest are extracted, adjacent CNTs are sequentially extracted by van der Waals forces. The extracted CNTs are oriented so that their longitudinal direction aligns with the direction from which they were extracted. Therefore, the multiple CNTs constituting the CNT fiber are oriented in one direction. The multiple CNTs constituting the CNT fiber are bonded to each other by van der Waals forces.

[0044] In the second step, when performing the coating described above, the article may be moved relative to the rotation axis of the CNT forest. Moving relative to the CNT forest means changing the position of the article along the rotation axis with respect to the CNT forest. If the article is linear, it can be moved relative to the article, for example, by unwinding the linear material and / or winding up the CNT coating. Relative movement of the article can also be achieved, for example, by moving the CNT forest in the axis direction of rotation. In the second step, it is preferable to coat the article with CNT fibers while moving it relative to the rotation axis of the CNT forest, and it is even more preferable to use a linear object as the article and to wind up the CNT-coated object while coating the surface of the linear object with CNT fibers.

[0045] An example of a method for manufacturing CNT fibers or CNT webs will be explained with reference to the drawings. Figures 1 to 5 show cases where a linear material is used as the article. Figure 1 is a top view illustrating the process of manufacturing a CNT web 20 containing multiple CNT fibers 22 using a carbon nanotube substrate (CNT substrate) 10 equipped with a CNT forest 12 provided on a substrate 11, and Figure 2 is a cross-sectional view along line AA in Figure 1.

[0046] The CNT web 20 shown in Figures 1 and 2 can be manufactured by pulling out multiple CNTs located at the ends of a CNT forest 12, which is provided on a substrate 11 and oriented perpendicular to the surface of the substrate 11, in a sheet-like manner in a direction parallel to the surface of the substrate 11, away from the CNT forest 12. In Figure 1, multiple CNT fibers 22 (i.e., CNT web 20) manufactured by pulling out multiple CNTs from the CNT forest 12 are bundled at their leading ends and attached to an article 2.

[0047] Figures 3A and 3B show an example of a method for coating an article using multiple CNT fibers. In the first step, an article 2, a substrate 11, and a CNT substrate 10 having a CNT forest 12 provided on the substrate 11 are prepared.

[0048] Article 2 is positioned to extend along the X-axis. For example, Article 2 is partially unwound from a winding body wound on a first roll (not shown) and fixed or wound onto a second roll (not shown). The unwound Article 2 extends along the X-axis with little to no slack between the first and second rolls, for example. Next, a plurality of CNT fibers 22 (CNT webs 20) or bundles drawn out in sheet form from the CNT forest 12 are attached to the surface of the unwound Article 2.

[0049] Next, article 2 is moved in the positive direction of the X-axis over time. For example, this movement of article 2 is achieved by unwinding article 2 from the first roll and winding it onto the second roll. The CNT substrate 10 is also rotated around article 2, using article 2 or an axis parallel to it that extends in the X-axis direction as the axis of rotation. In Figures 3A and 3B, the CNT substrate 10 rotates along the dashed line R. As a result, the CNT fibers 22 or bundles obtained from the CNT forest 12 wrap around the surface of article 2, and the position where they wrap (covering position) on article 2 moves. Thus, a CNT fiber layer 4 covering article 2 is formed, and a CNT coated object 1 is obtained. The CNT fibers 22 or bundles cover article 2, for example, in a spiral pattern. The CNT coated object 1 is wound onto, for example, the second roll.

[0050] The CNT substrate 10 may be rotated around the article 2 while being moved in the negative direction of the X-axis. In this case, the trajectory of the CNT substrate 10 will be spiral, as shown by the dashed line R' in Figure 3C. Even when the CNT substrate 10 is moved in the negative direction of the X-axis, the CNT fibers 22 or bundles obtained from the CNT forest 12 wrap around the surface of the article 2, and the position where they wrap around (covering position) on the article 2 moves. Thus, a CNT fiber layer 4 covering the article 2 is formed. The CNT fibers 22 or bundles cover the article 2, for example, in a spiral shape.

[0051] When rotating the CNT substrate 10 around the article 2, it is preferable not to rotate the article 2, that is, not to rotate the article 2 with the axis of rotation in the X-axis direction or a direction parallel thereto. If the article does not rotate, there is less risk of damaging the article when coating it with CNT fibers. It is preferable to wrap the CNT fibers or bundles of CNTs around an article so that the CNT fibers or bundles of CNTs drawn from the CNT forest do not become loose.

[0052] When a rotating member is prepared in the first step, for example, as shown in Figures 4A and 4B, the CNT substrate 10 is placed on a cylindrical member 32 or a ring-shaped member 34 as a rotating member, and the CNT substrate 10 can be rotated around the article 2 by rotating the cylindrical member 32 or ring-shaped member 34 around the article 2 (for example, rotating in the direction of P in Figures 4A and 4B). Rotating the cylindrical member 32 or ring-shaped member 34 around the article 2 means making the cylindrical member 32 or ring-shaped member 34 rotate on its own axis around the article 2, and rotating the CNT substrate 10 around the article 2 means making the CNT substrate 10 revolve around the article 2.

[0053] It is preferable to adjust the movement speed of the article 2 (linear speed of article 2, feed speed of article 2, or winding speed of CNT coating 1) in accordance with the rotation speed of the CNT substrate 10. For example, it is preferable to synchronize the rotation speed and the movement speed. This synchronization allows the CNT fibers 22 to be tightly wound onto the article 2.

[0054] By adjusting the rotation speed and the moving speed, for example, the orientation angle (angle θ shown in Figures 5A and 5B), which is the angle between the CNT fiber 22 and the article 2, can be controlled. By keeping the rotation speed and the moving speed constant, the orientation angle can be kept constant. By changing the rotation speed and / or the moving speed while coating, the orientation angle can be changed without stopping the coating process.

[0055] After the CNT fiber layer 4 is formed, the CNT coating 1 may be brought into contact with a solvent, and then the solvent may be removed. Contact may be performed by immersing the CNT coating 1 in the solvent, by spraying the solvent, by applying the solvent, or by dropping the solvent. As the solvent, a solvent that vaporizes easily can be used. Examples of such solvents include lower alcohols such as ethanol and organic solvents such as acetone. It is preferable to bring the CNT coating 1 into contact with a solvent and remove the solvent by vaporization, as this tends to improve the adhesion between the CNT fiber layer 4 and the article 2.

[0056] Figure 5B shows an example of a CNT coating 1 obtained when the rotational speed of the CNT substrate 10, the relative movement speed of the article 2, and the width of the bundle of CNT fibers 22 that spirally covers the article 2 (L0 in Figure 5B) are kept constant (side view of the CNT coating 1). In Figure 5B, a part of the CNT coating 1 is shown in magnified view. When the angular velocity of the CNT substrate 10 is w (rad / sec), the thickness (diameter) of the article 2 is 2r (m), the relative movement speed of the article 2 is v (m / sec), and the distance between the centerlines of the bundles that spirally cover the article 2 is L (m), then w, r, v and L have the relationship shown in equation (I) below, and w, r, v and the orientation angle θ have the relationship shown in equation (II) below.

[0057]

number

[0058]

number

[0059] Furthermore, if the width of the bundle that spirally covers article 2 is L0 (m), the spacing ΔL (m) between adjacent bundles on article 2 is expressed by the following formula (III).

[0060]

number

[0061] In equation (III), w, r, and v are the same as in equation (I). When ΔL is positive, adjacent bundles on article 2 do not overlap, and the bundles cover article 2 in such a way that there are gaps between them. When ΔL is negative, adjacent bundles cover article 2 in such a way that they overlap. ΔL is preferably 0 or negative.

[0062] The angular velocity of the CNT substrate 10 is preferably 0.1 to 12.6 rad / second, more preferably 0.3 to 9.4 rad / second, and even more preferably 0.5 to 6.3 rad / second. In one preferred embodiment, the CNT substrate 10 rotates (revolves) along a circle with a radius of 1 cm to 1 m. In another preferred embodiment, the CNT substrate 10 rotates (revolves) along a circle with a radius of α+0.5 cm to α+1 m. In a more preferred embodiment, the CNT substrate 10 rotates (revolves) along a circle with a radius of α+1 cm to α+50 cm. α refers to the thickness of the article 2 if its shape is, for example, linear; the thickness of the article 2 if its shape is, for example, strip or plate-shaped; and the diameter of the article 2 if its shape is, for example, spherical. For example, if article 2 is a linear object with a thickness of 80 μm to 1 cm, and the dashed line R in Figures 3A and 3B is a circle with a radius of 3 cm, that is, if the CNT substrate 10 is rotated along the circumference of a circle with a radius of 3 cm, the rotation speed of the CNT substrate 10 is preferably 100 to 1000 cm / min, more preferably 150 to 800 cm / min, and even more preferably 180 to 600 cm / min.

[0063] The relative movement speed of article 2 is preferably 0.1 to 20 cm / min, more preferably 0.5 to 15 cm / min, and even more preferably 0.8 to 12 cm / min. The orientation angle is preferably 0.8 to 70°, more preferably 1.6 to 60°. The mechanical properties of the CNT coating tend to improve as the orientation angle approaches 45°. The orientation angle is measured by observing the surface of the CNT coating with an optical microscope or the like.

[0064] For example, if article 2 is an optical fiber with a diameter of 125 μm, the width of the CNT substrate 10 required to cover the optical fiber by 1 cm with an orientation angle of approximately 45° (the length of the CNT forest 12 in the direction in which the multiple CNT fibers 22 constituting the CNT web 20 are aligned when the CNT web 20 is drawn out from the CNT forest 12, i.e., length d in Figure 1) is preferably 1 to 10 cm, more preferably 2 to 8 cm, and even more preferably 3 to 5 cm, and it is preferable to adjust the rotation speed of the CNT substrate 10 and the movement speed of the optical fiber within the above range.

[0065] When installing the CNT substrate 10 on the cylindrical member 32 or ring-shaped member 34, the CNT substrate 10 may be positioned on the inner surface or inner circumference of the rotating member such that the CNT forest 12 faces the article 2 and the substrate 11 faces outwards, or the CNT substrate 10 may be positioned on the outer surface or outer circumference of the rotating member such that the substrate 11 faces the article 2 and the CNT forest 12 faces outwards. From the viewpoint of the designability of the manufacturing apparatus for the CNT coated material 1 and the ease of forming the CNT fiber layer 4, it is preferable to position and rotate the CNT substrate 10 so that the CNT forest 12 faces the article 2 and the substrate 11 faces outwards, as shown in Figures 4A and 4B.

[0066] The CNT web 20 may be drawn from one location in the CNT forest 12 and the bundle attached to the item 2, or the CNT web 20 may be drawn from multiple locations in the CNT forest 12 and the bundle attached to the item 2.

[0067] More than one CNT substrate 10 may be used. That is, two or more CNT substrates 10 (for example, a first and a second CNT substrate) may be rotated around the article 2 with the X-axis direction or an axis parallel thereto as the axis of rotation. In this case, a plurality of CNT fibers 22 (CNT webs 20) or bundles drawn from the CNT forest 12 of the first CNT substrate are attached to the surface of the unfurled article 2, and a plurality of CNT fibers 22 (CNT webs 20) or bundles drawn from the CNT forest 12 of the second CNT substrate are attached to the surface of the unfurled article 2. As a result, the CNT fibers 22 or bundles obtained from the CNT forest 12 of the first CNT substrate wrap around the surface of the article 2, and the CNT fibers 22 or bundles obtained from the CNT forest 12 of the second CNT substrate wrap around the surface of the article 2, forming a CNT fiber layer 4 that covers the article 2. The number of CNT substrates can be, for example, 1 to 5, 1 to 3, or 1 to 2. Alternatively, the CNT substrate 10 itself may be shaped like a cylinder, and the CNT forest 12 may surround the optical fiber 2 360 degrees.

[0068] When multiple items are prepared in the first step, rotating the CNT forest around the multiple items allows the multiple items to be covered together with CNT fibers or bundles thereof.

[0069] The thickness of the CNT fiber layer is preferably 1 to 50 μm, more preferably 1 to 30 μm, even more preferably 2 to 15 μm, and particularly preferably 3 to 9 μm, from the viewpoint of heat resistance, flexibility, and adhesion to article 2. The average thickness of the CNT fiber layer is measured by observing a cross-section perpendicular to the length direction of the CNT coating using a scanning electron microscope (SEM).

[0070] If the article is tubular, the surface of the article covered by the CNT fibers refers to the outer surface of the tubular object.

[0071] [Equipment for manufacturing carbon nanotube coated materials] The CNT coating manufacturing apparatus of this disclosure is A hollow, rotatable member capable of self-rotation, A CNT substrate is installed on the rotating member, A moving device that moves an article to be coated with CNTs relative to the rotation axis of a rotating member, It is equipped with.

[0072] A rotatable, hollow rotating member is capable of rotating about one axis of rotation and has a hollow space inside the member that extends parallel to the axis of rotation, through which an article to be covered can pass. Examples of rotating members include cylindrical members and ring-shaped members.

[0073] The above-mentioned CNT substrate comprises a substrate and a CNT forest on the substrate. The CNT substrate may be installed on the inner surface or inner circumference of the rotating member such that the CNT forest faces the article and the substrate faces outward, or it may be installed on the outer surface or outer circumference of the rotating member such that the substrate faces the article and the CNT forest faces outward. From the viewpoint of the design of the manufacturing apparatus for CNT coatings and the formation of the CNT fiber layer, it is preferable that the CNT substrate is installed such that the CNT forest faces the article and the substrate faces outward. The CNT substrate may be installed as a single unit or as a multiple unit. Furthermore, it may be installed along the entire circumference of the rotating member or on only a portion of the circumference.

[0074] The above-described moving device may be a device that fixes the article to be covered and moves the rotating member in the direction of rotation, or it may be a device that moves the article in the direction of rotation of the rotating member without moving the rotating member. The above-described moving device makes it possible to move the covering position on the surface of the article, which is covered by the CNT substrate rotating around the article, in the direction of rotation of the rotating member. Examples of the above-mentioned moving devices include a dispensing device for dispensing articles and a winding device for winding up CNT-coated materials. Examples of dispensing devices and winding devices include rolls. When the above-mentioned articles are linear in shape, dispensing devices and winding devices are preferably used as moving devices. Examples of moving devices include devices equipped with wheels that are connected to a rotating member and can move the rotating member.

[0075] An example of a CNT coating manufacturing apparatus will be explained using drawings. Figures 6A, 6B, and 7 show the case where a linear object is used as the object to be coated. Figures 6A and 6B show an example of a rotatable, hollow rotating member, a CNT substrate installed on the rotating member, and a moving device. In Figure 6A, a rotating member 30, a CNT substrate 10 installed on the rotating member 30, and a roll 42 (a first roll 43 and a second roll 44) as a moving device are shown. In Figure 6B, the rotating member 30 is equipped with wheels and a moving device 46 for moving the rotating member 30 is connected to it. In Figure 6B, the article 2 to be covered is fixed to a fixed member (not shown). The rotating member 30 rotates on an axis in the X-axis direction or an axis parallel thereto, for example, in the direction of P in Figures 6A and 6B.

[0076] In the above manufacturing apparatus, the article 2 moves relative to the rotating member 30 in the positive X-axis direction over time, either by the first roll 43 and the second roll 44, or by the moving device 46. Relative movement means that the position of the article 2 along the X-axis direction (along the rotation axis direction of the rotating member) relative to the rotating member 30 changes. For example, in Figure 6A, the article 2 is moved by unwinding it from the first roll 43 and winding the CNT coating 1 onto the second roll 44. Also, in Figure 6B, the article 2 moves relative to the rotating member 30 by the rotating member 30 itself moving in the negative X-axis direction.

[0077] By rotating the rotating member 30 with the X-axis direction or an axis parallel thereto as the axis of rotation, the CNT substrate 10 is rotated (revolved) around the article 2. As described above, the first roll 43 and the second roll 44, or the moving device 46, and the rotating member 30 work in conjunction, causing the CNT fibers 22 or bundles obtained from the CNT forest 12 to wrap around the surface of the article 2, and the position where the fibers are wrapped (covering position) on the article 2 to move. Thus, a CNT fiber layer 4 covering the article 2 is formed, and a CNT-covered object 1 is obtained.

[0078] The above manufacturing apparatus may further include a control device for adjusting the rotational speed of the rotating member and the moving speed of the article in the moving device. Figure 7 shows an example of the above manufacturing apparatus further including a control device 50. If the above manufacturing apparatus includes a control device 50, and the control device 50 adjusts, for example, the rotational speed of the rotating member 30, the rotational speed of the first roll 43, and the rotational speed of the second roll 44 by synchronizing them, the coating state, such as the orientation angle which is the angle between the CNT fibers 22 or bundles thereof and the article 2, can be controlled.

[0079] This disclosure relates, for example, to the following [1] to

[10] . [1] The first step involves preparing the materials and the carbon nanotube forest, and A second step involves attaching carbon nanotube fibers or bundles drawn from the carbon nanotube forest to the surface of the article, and then rotating the carbon nanotube forest around the article to coat the surface of the article with the carbon nanotube fibers or bundles. A method for producing a carbon nanotube coated material having the following characteristics.

[0080] [2] A method for producing a carbon nanotube coated article according to [1], wherein the coating is performed in the second step while moving the article relative to the carbon nanotube forest in the direction of the rotation axis.

[0081] [3] A method for producing a carbon nanotube coated material according to [1] or [2], wherein the carbon nanotube forest is provided on a substrate.

[0082] [4] A method for producing a carbon nanotube coated material according to any one of [1] to [3], wherein the article is linear.

[0083] [5] A method for producing a carbon nanotube coated material according to [4], wherein in the second step, the surface of the linear material is coated with carbon nanotube fibers while the carbon nanotube coated material is wound up.

[0084] [6] A method for producing a carbon nanotube coated material according to [4] or [5], wherein the linear material is an optical fiber.

[0085] [7] A method for producing a carbon nanotube coated material according to [6], wherein the thickness of the carbon nanotube fiber layer covering the surface of the optical fiber is 1 to 50 μm.

[0086] [8] A manufacturing apparatus for carbon nanotube coated materials, The aforementioned manufacturing apparatus, A hollow, rotatable member capable of self-rotation, A carbon nanotube substrate is placed on the rotating member, A moving device for moving an article to be coated with carbon nanotube fibers relative to the rotation axis of the rotating member, Equipped with, The carbon nanotube substrate comprises a substrate and a carbon nanotube forest on the substrate. A manufacturing apparatus for rotating a carbon nanotube forest around an article that is moving relatively within the inner space of the rotating member, thereby coating the surface of the article with carbon nanotube fibers.

[0087] [9] The apparatus for manufacturing a carbon nanotube coated material according to [8], wherein the moving device is a dispensing device for dispensing the article and a winding device for winding the carbon nanotube coated material.

[0088]

[10] The apparatus for manufacturing carbon nanotube coated articles according to [8] or [9], further comprising a control device for adjusting the rotational speed of the rotating member and the moving speed of the article in the moving device. [Examples]

[0089] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0090] [Example 1] <1st process> (Goods) As an example, we prepared a quartz glass fiber with a length of 52 m and a diameter of 125 μm, whose surface was not coated with resin or other materials.

[0091] (CNT Forest) Two wafers coated with a catalyst for CNT growth were prepared, and vertically oriented CNTs were grown from the catalyst using chemical vapor deposition (CVA), resulting in the creation of a total of two vertically oriented CNT forests oriented perpendicular to the wafers. The CNTs constituting the CNT forest are multi-walled carbon nanotubes, with an average length of 250 μm per tube, an average diameter of 6-10 nm, a carbon purity of 99.8% or higher, and a crystallinity (D / G ratio) of 0.6-0.8.

[0092] <Second process> A cylindrical member with an inner diameter of 6 cm was prepared, and an uncoated quartz glass fiber was passed through the inside of the cylindrical member. A substrate on which CNT forests were formed was placed on the inner wall surface of the cylindrical member so that each CNT forest faced the other. A CNT web was created by picking up CNTs located at the ends of the CNT forest formed on the catalyst substrate with a picking tool and pulling them out in a sheet-like manner. The pulled-out portion was then brought into contact with the quartz glass fiber, and bundles of multiple CNT fibers constituting the CNT web were attached to it.

[0093] A cylindrical member was rotated at 30 rpm to wrap CNT fibers around the surface of a quartz glass fiber, and the quartz glass fiber with the wrapped CNT fibers was then wound up on a rotating roll with a diameter of 20 cm. The winding speed of the rotating roll was 11.7 mm / min. The quartz glass fiber was not rotated along its length axis. As a result, the CNT fibers wrapped around the outer surface of the quartz glass fiber, coating it. After coating with CNT fibers and before winding with the rotating roll, ethanol was sprayed and then vaporized to obtain a 50 m long carbon nanotube coated optical fiber (1). The orientation angle between the CNT fibers and the quartz glass fiber in the carbon nanotube coated optical fiber (1) was approximately 45°. The thickness of the CNT fiber layer covering the outer surface of the quartz glass fiber was observed to be approximately 6 μm (5.8~6.5 μm) by SEM.

[0094] In Example 1, the quartz glass fiber was coated with CNT fibers without damaging it. [Explanation of symbols]

[0095] 1...CNT coating 2...Goods 4…CNT fiber layer 6… Bundles of CNT fibers that spirally cover an article. 8…The centerline of the bundle of CNT fibers that spirally covers the article. 10…CNT substrate 11… Circuit board 12…CNT Forest 20...CNT Web extracted from CNT Forest 22...CNT fibers that make up the CNT web 30…Rotating member 32...Cylindrical member 34... Ring-shaped member 42, 43, 44... Roll 46... A moving device equipped with wheels for moving rotating members. 50…Control device

Claims

1. The first step involves preparing the materials and the carbon nanotube forest, and A second step involves attaching carbon nanotube fibers or bundles drawn from the carbon nanotube forest to the surface of the article, and then rotating the carbon nanotube forest around the article to coat the surface of the article with the carbon nanotube fibers or bundles. A method for producing a carbon nanotube coated material having the following characteristics.

2. The method for manufacturing a carbon nanotube coated article according to claim 1, wherein in the second step, the coating is performed while moving the article relative to the carbon nanotube forest in the direction of the rotation axis.

3. The method for producing a carbon nanotube coated material according to claim 1, wherein the carbon nanotube forest is provided on a substrate.

4. The method for producing a carbon nanotube coated article according to claim 1, wherein the article is a linear material.

5. The method for producing a carbon nanotube coated material according to claim 4, wherein in the second step, the surface of the linear material is coated with carbon nanotube fibers while the carbon nanotube coated material is wound up.

6. The method for producing a carbon nanotube coated material according to claim 4, wherein the linear material is an optical fiber.

7. The method for producing a carbon nanotube coated product according to claim 6, wherein the thickness of the carbon nanotube fiber layer covering the surface of the optical fiber is 1 to 50 μm.

8. A manufacturing apparatus for carbon nanotube coated materials, The aforementioned manufacturing apparatus, A hollow, rotatable member capable of self-rotation, A carbon nanotube substrate is placed on the rotating member, A moving device for moving an article to be coated with carbon nanotube fibers relative to the rotation axis of the rotating member, Equipped with, The carbon nanotube substrate comprises a substrate and a carbon nanotube forest on the substrate. A manufacturing apparatus for rotating a carbon nanotube forest around an article that is moving relatively within the inner space of the rotating member, thereby coating the surface of the article with carbon nanotube fibers.

9. The apparatus for manufacturing a carbon nanotube coated material according to claim 8, wherein the moving device is a dispensing device for dispensing the article and a winding device for winding the carbon nanotube coated material.

10. The apparatus for manufacturing a carbon nanotube coated material according to claim 8, further comprising a control device for adjusting the rotational speed of the rotating member and the moving speed of the article in the moving device.

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