JP6476245B2 - CVD apparatus for carbon nanostructure growth and method for producing carbon nanostructure - Google Patents

Description

  The present invention relates to a CVD apparatus for growing carbon nanostructures for growing carbon nanostructures such as carbon nanotubes and graphene, and a method for producing the carbon nanostructures.

  A CVD apparatus for growing this type of carbon nanostructure is known from Patent Document 1, for example. This includes a processing furnace, a transporting means for transporting a processing object so as to pass through the processing furnace, a gas introducing means for introducing a carbon-containing source gas into the processing furnace, and a heating means for heating the source gas. With. The conveying means includes a plurality of rollers arranged at intervals and an endless mesh belt (band-like body) wound around these rollers, and the mesh belt positioned on the upper side by rotationally driving the rollers. The processing object placed on this part is conveyed so as to pass through the inside of the processing furnace. Then, the carbon nanostructure is grown on the surface of the processing object including the mounting surface side of the processing object by bringing the heated source gas into contact with the surface of the processing object while passing through the processing furnace. It is like that.

  Here, in the conveying means such as Patent Document 1, since a predetermined tension is always applied to the mesh belt, in order to convey the object to be processed stably with high durability, as a wire constituting the mesh belt, It is necessary to use a material having a relatively large outer diameter (wire diameter) or to increase mechanical strength by increasing the number of wires used to reduce the aperture ratio. In such a case, it has been found that the carbon nanostructure does not grow (a so-called belt mark is generated) in the portion facing the wire on the mounting surface side of the processing object. This is considered to be due to the fact that, for example, when the wire diameter is large, the source gas does not reach the projection surface of the wire on the mounting surface side of the processing object. As a result, there is a problem that it cannot be used for applications in which carbon nanotubes are grown on both sides of a substrate as a battery electrode material.

Japanese Patent No. 4581146

  In view of the above, the present invention provides a CVD apparatus for carbon nanostructure growth and a carbon nanostructure manufacturing method capable of growing the carbon nanostructure over the entire surface of the object to be processed. That is the subject.

  In order to solve the above problems, a processing furnace, a transporting means for transporting a processing object so as to pass through the processing furnace, a gas introducing means for introducing a carbon-containing source gas into the processing furnace, and a source gas A CVD apparatus for carbon nanostructure growth according to the present invention, which comprises a heating means for heating, and grows the carbon nanostructure on the surface of the processing object passing through the processing chamber. A plurality of openings that allow the growth of the carbon nanostructure on the mounting surface side of the processing object is formed in the band, and the band and the processing object A mesh body is interposed between the two.

  According to the present invention, the mesh body interposed between the belt-like body and the object to be processed does not always have a predetermined tension applied thereto, so that it is not necessary to consider the mechanical strength. For this reason, for example, by reducing the wire diameter of the wire constituting the mesh body as much as possible or increasing the aperture ratio of the mesh body as much as possible, the entire surface on the mounting surface side of the processing object In the meantime, the heated source gas can be made to reach. As a result, the carbon nanostructure can be grown over the entire surface of the object to be treated.

  By the way, in order to allow the heated source gas to reach the entire surface of the processing object on the mounting surface side, it is conceivable that the processing object is floated from the strip using a jig. It takes time and effort to attach the jig to the substrate, which reduces productivity. In the present invention, the belt-like body is formed of a mesh belt, the mesh body is formed into a belt-like shape by assembling wires having an outer diameter smaller than that of the wire constituting the mesh belt, and the mesh belt travels along It is preferable to make it run. According to this, since attachment of a jig | tool becomes unnecessary, productivity does not fall.

  Moreover, in this invention, it is preferable that the aperture ratio of the said mesh body is set to the range of 50-99.8%. When the aperture ratio is less than 50%, the raw material gas is not sufficiently supplied, and the growth of the carbon nanostructure may be deteriorated or the mesh shape may be marked, while the aperture ratio is 99.8%. If it exceeds, the mechanical strength of the mesh body may decrease.

  Further, in the present invention, the mesh body is formed into a sheet-like shape, the mesh body is held in a wound state, and a feeding roller that feeds out the mesh body and the mesh body that is fed out from the feeding roller are wound up. In the case of including a winding roller, the conveying means is disposed between the feeding roller and the winding roller, and includes a plurality of rollers around which the mesh belt is wound, and a driving roller among the plurality of rollers. You may comprise with the drive part which rotationally drives. In this case, if the mesh body is overlapped on the mesh belt, the mesh body can be run along with the traveling of the traveling mesh belt when the driving roller is rotated and the mesh belt is driven at a predetermined speed. Thereby, it is not necessary to provide a driving unit that rotationally drives the feeding roller and the winding roller, and the cost of the CVD apparatus can be reduced.

  The carbon nanostructure manufacturing method of the present invention using the above-described CVD apparatus for carbon nanostructure growth is a preparatory step of placing the object to be processed on the mesh body after the strip and the mesh body are overlapped Then, the belt-like body and the mesh body are run in the processing furnace, and while passing through the processing furnace, the heated source gas is brought into contact with the surface of the processing object, and the carbon nanostructure is formed on the surface of the processing object. A first step in which the carbon nanostructures that grow on the mounting surface side of the object to be processed come into contact with each wire constituting the mesh body, and in contact with each wire. The carbon nanostructure further grows, and the carbon nanostructure grows through a second stage in which the object to be treated is supported by the grown carbon nanostructure.

  According to the present invention, in the second stage, a gap is formed between the processing object supported by the carbon nanostructure and the mesh body, and the entire surface of the processing object is placed through the gap. Thus, the heated raw material gas can be made to reach. Thereby, the carbon nanostructure can be grown over the entire surface on the mounting surface side of the processing object.

The typical sectional view showing the CVD device of the embodiment of the present invention. (A)-(c) is a schematic diagram explaining the manufacturing method of the carbon nanostructure of embodiment of this invention.

  Hereinafter, with reference to the drawings, an example in which a processing object is a metal foil Fm having a catalyst (not shown) formed on the surface and carbon nanotubes Ct are grown on the surface of the metal foil Fm passing through the processing furnace 1 will be described. Next, an embodiment of the CVD apparatus of the present invention will be described.

  Referring to FIG. 1, M is a CVD apparatus according to an embodiment of the present invention. The CVD apparatus M includes a cylindrical processing furnace 1 for growing carbon nanotubes on a metal foil Fm. In the following, the direction in which the metal foil Fm is conveyed in the processing furnace 1 is the right side in the X-axis direction (left-right direction in FIG. 1), and the width direction of the metal foil Fm is the Y-axis direction (the direction perpendicular to the paper surface in FIG. 1). The direction orthogonal to the plane including the X-axis direction and the Y-axis direction will be described as the Z-axis direction (the vertical direction in FIG. 1).

  An upstream auxiliary chamber 2 and a downstream auxiliary chamber 3 are connected to both sides of the processing furnace 1 in the X-axis direction. A distal end of a gas pipe 12 having a mass flow controller 11 interposed therein, which communicates with a gas source (not shown), is disposed in the processing furnace 1 so that a carbon-containing source gas can be introduced into the processing furnace 1 at a predetermined flow rate. It has become. In this case, the mass flow controller 11 and the gas pipe 12 constitute the gas introduction means in the claims.

  A heating means 13 is provided outside the processing furnace 1, and the raw material gas introduced into the processing furnace 1 is heated, whereby the heated raw material gas can be supplied to the surface of the metal foil Fm. As the heating means 13, since well-known things, such as a lamp | ramp and a heating wire, can be used, detailed description is abbreviate | omitted here. Upper and lower heat insulating materials 14 a and 14 b are provided outside the heating means 13.

  The CVD apparatus M includes transport means 15 that transports the metal foil Fm so as to pass through the processing furnace 1. The conveying means 15 includes an endless mesh belt Vm as a belt-like body, and a plurality of (four in this embodiment) rollers 15a, 15b, 15c around which the mesh belt Vm is wound. 15d. A rotating shaft (not shown) of the motor DM is connected to the roller 15a, and when the roller 15a is rotationally driven by the motor DM, the mesh belt Vm travels at a predetermined speed. Since a predetermined tension (for example, 20 to 80 N) is applied to the mesh belt Vm, the mesh belt Vm is mechanically assembled by assembling a wire W1 constituting the mesh belt Vm having a relatively large outer diameter (wire diameter) d1. Has strength. The mesh belt Vm has a plurality of openings that allow the carbon nanotubes Ct to grow on the mounting surface Fm1 side of the metal foil Fm.

  The auxiliary chamber 2 on the upstream side is held in a state in which the metal foil Fm is wound, and is held in a state in which the feeding roller 21 for feeding out the metal foil Fm and the belt-like mesh body Bm is wound, and downstream of the feeding roller 21. A feeding roller 22 for feeding the mesh body Bm on the side is provided. As the mesh body Bm, one formed by assembling a wire W2 having an outer diameter smaller than the wire W1 constituting the mesh belt Vm (for example, a mesh belt) is used. The outer diameter d2 of the wire W2 of the mesh body Bm is preferably set in the range of 0.01 to 0.1 mm. If the outer diameter d2 is less than 0.01 mm, the temperature W rises and the wire W2 extends and hangs down to the mesh belt Vm side, and the effect of using the mesh body Bm may be reduced. If it exceeds 0.1 mm, the metal foil Fm cannot be sufficiently floated from the wire W2, and the shape of the mesh body Bm may be left behind. Moreover, it is preferable that the aperture ratio of the mesh body Bm is set in the range of 50 to 99.8%. When the aperture ratio is less than 50%, the raw material gas is not sufficiently supplied, and the growth of the carbon nanostructure may be deteriorated or the mesh shape may be marked, while the aperture ratio is 99.8%. Exceeding may cause the mechanical strength of the mesh body Bm to decrease.

  The auxiliary chamber 3 on the downstream side passes through the processing furnace 1 and winds up and collects the metal foil Fm grown with the carbon nanotubes Ct, and the mesh body Bm is wound on the upstream side of the winding roller 31. A take-up roller 32 is provided for collecting and collecting. Here, it is considered that the metal foil Fm with the carbon nanotube Ct and the mesh body Bm are once wound up, but when the mesh body Bm is pressed against the carbon nanotube Ct, the mesh body Bm is marked. Therefore, it is preferable that the mesh body Bm and the metal foil Fm are separated and wound up and collected.

  By configuring the conveying means 15 in this way, when the roller 15a is rotationally driven by the motor DM, the mesh belt Vm travels at a predetermined speed. A mesh body Bm is superimposed on the traveling mesh belt Vm, and a metal foil Fm is placed on the mesh body Bm. For this reason, the mesh body Bm that has been unrolled as the mesh belt Vm travels travels, and the metal foil Fm that has been unrolled as the mesh body Bm travels passes through the processing furnace 1 at a predetermined speed (for example, , 0.01 to 1.0 m / min). By supplying the source gas heated by the heating means 13 to the surface of the metal foil Fm passing through the processing furnace 1, carbon nanotubes Ct grow from the surface.

  The CVD apparatus M has known control means including a microcomputer, a sequencer, etc., and the control means controls the operation of the mass flow controller 11, the operation of the heating means 13, the operation of the motor DM, and the like. It has become.

  Next, referring also to FIG. 2, it is assumed that a catalyst film is formed on the surface of the metal foil Fm using the CVD apparatus M, and carbon nanotubes Ct are grown on the surface of the metal foil Fm. Taking a case as an example, an embodiment of a method for producing a carbon nanostructure will be described. Ni foil can be used as the metal foil Fm, and Fe film can be used as the catalyst film.

  First, the mesh belt Vm is set around the rollers 15a, 15b, 15c, and 15d, the mesh belt Vm is set, the metal foil Fm is set on the feeding roller 21, and the mesh body is set on the feeding roller 22. Set Bm. Thereby, the mesh body Bm is overlaid on the mesh belt Vm, and the metal foil Fm is placed on the mesh body Bm (preparation step).

  Here, the belt-like body is not limited to a mesh shape like the mesh belt Vm as long as it has an opening and can support the mesh body Bm. For example, a ladder chain or a ladder wire (roller chain) ) Or a crawler track shape of an endless track with thin trays connected. That is, it is possible to ensure an aperture ratio capable of supplying a raw material gas, which will be described later, and if the growth of the carbon nanotubes Ct on the surface of the processing object (metal foil Fm) placed on the mesh body Bm is not inhibited, The shape of the strip is not limited.

  Next, the mesh belt Vm travels at a predetermined speed by rotationally driving the roller 15a by the motor DM. Since the mesh body Bm is superimposed on the traveling mesh belt Vm, the mesh body Bm is fed out from the feed roller 22 provided in the upstream auxiliary chamber 2 and the fed mesh body Bm is processed together with the mesh belt Vm. After traveling in the furnace 1 to the right in the X-axis direction, it is wound up by a winding roller 32 provided in the auxiliary chamber 3 on the downstream side. Further, since the metal foil Fm is placed on the mesh body Bm, the metal foil Fm is fed out from the feeding roller 21 provided in the auxiliary chamber 2, and the fed metal foil Fm is processed together with the mesh body Bm in the processing furnace 1. The vehicle travels to the right in the X-axis direction, passes through the processing chamber 1, and is then wound by a winding roller 31 provided in the auxiliary chamber 3 on the downstream side. The time for the metal foil Fm to pass through the processing furnace 1 can be appropriately set according to the length (for example, 125 μm) of the carbon nanotube Ct grown from the surface of the metal foil Fm.

  Thus, while the metal foil Fm passes through the processing furnace 1, the mass flow controller 11 is controlled to introduce a carbon-containing source gas into the processing furnace 1 at a predetermined flow rate (for example, 100 to 2000 sccm) (at this time, The pressure in the processing furnace 1 is 1 kPa to atmospheric pressure). As the carbon-containing source gas, hydrocarbons such as ethylene gas, acetylene gas and methane gas, and alcohols such as ethanol can be used. A dilution gas may be introduced into the processing furnace 1 together with such a raw material gas, and a rare gas such as hydrogen gas, nitrogen gas, or argon can be used as the dilution gas. When the heating means 13 is operated in this state to heat the source gas to a predetermined temperature, the heated source gas is supplied to the surface of the metal foil Fm, and carbon nanotubes grow from the surface of the metal foil Fm (growth step). The heating temperature can be appropriately set in the range of 400 to 1050 ° C. according to the type of source gas. For example, the temperature can be set to 750 ° C. when ethylene gas is used, 720 ° C. when acetylene gas is used, and 800 ° C. when methane gas is used.

  According to this embodiment, since the mesh body Bm interposed between the mesh belt Vm and the metal foil Fm is not always given a predetermined tension, it is not necessary to consider the mechanical strength. For this reason, for example, by making the wire diameter d2 of the wire W2 constituting the mesh body Bm as small as possible, the heated source gas reaches the entire surface on the mounting surface Fm1 side of the metal foil Fm. Can be. As a result, the carbon nanotubes Ct can be grown over the entire surface of the metal foil Fm.

  In the growth step, the first stage (see FIG. 2A) in which the carbon nanotubes Ct grown on the mounting surface Fm1 side of the metal foil Fm are in contact with the wire W2 constituting the mesh body Bm, respectively, and each wire. The carbon nanotubes Ct in contact with W2 further grow, and the carbon nanotubes Ct are grown through a second stage in which the grown carbon nanotubes Ct support the metal foil Fm. When the metal foil Fm is supported by the carbon nanotubes Ct in the second stage, a gap S is formed between the mesh body Bm and the metal foil Fm, and on the placement surface Fm1 side of the metal foil Fm via the gap S. The heated source gas can be surely delivered to the projection surface of the wire W2. As a result, the carbon nanotubes Ct can be grown over the entire surface of the metal foil on the mounting surface side.

  By the way, in order to allow the heated source gas to reach the entire surface of the metal foil Fm on the mounting surface Fm1 side, that is, to form the gap S, the metal foil Fm is floated using a jig. However, it takes time and effort to attach the jig to the metal foil Fm, which reduces productivity. In the present embodiment, the belt-like body is configured by the mesh belt Vm, and the mesh body Bm is formed into a belt-like shape by assembling the wire W2 having an outer diameter d2 smaller than the wire W1 constituting the mesh belt Vm. It is only necessary to travel along with the travel, and it is not necessary to attach a jig, so productivity does not decrease.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. In the said embodiment, although the case where the metal foil Fm was used as a process target object was demonstrated to the example, it is not limited to this and another base material can be used.

  In the above embodiment, the case where the raw material gas introduced into the processing furnace 1 is heated by the heating means 13 has been described as an example. However, it is only necessary that the heated raw material gas can be supplied to the surface of the processing object. The source gas heated in step 1 may be introduced into the processing furnace 1.

  In the above embodiment, the case where the carbon nanotube Ct is grown has been described as an example. However, the present invention can also be applied to the case where other carbon nanostructures such as graphene are grown.

  In the above embodiment, the case where the processing object is a sheet-like metal foil Fm and the mesh body Bm is formed into a sheet has been described as an example. However, the shape of the mesh body Bm is not limited to this, for example, the processing object May be formed in a rectangular shape having a contour corresponding to the contour of the base material. In this case, the base material can be passed through the processing chamber 1 by placing the mesh body Bm supporting the base material on the traveling mesh belt Vm.

  Further, another motor for driving the feeding rollers 21 and 22 and the winding rollers 31 and 32 may be further provided. However, if the mesh belt Vm is traveled at a predetermined speed as in the above embodiment, the mesh body Bm travels along with the travel of the traveling mesh belt Vm, and the metal foil Fm travels. It is not necessary to provide a motor, and the cost of the CVD apparatus can be reduced.

  In the above embodiment, the case where the cross section of the wire W2 of the mesh body Bm is a perfect circle has been described as an example. However, the cross section of the wire W2 is not limited to this, and a wire having an elliptical, triangular, or rhombic cross section may be used. Although it is possible, it is preferable to use the wire W2 having a cross section in line contact with the mounting surface Fm1 of the metal foil Fm.

  Bm ... mesh body, Fm ... metal foil (processing object), Fm1 ... mounting surface, M ... CVD apparatus for carbon nanostructure growth, Vm ... mesh belt (band-like body), W1 ... mesh belt Vm Wire material, W2 ... Wire material of mesh body Bm, 1 ... Processing furnace, 11 ... Mass flow controller (gas introduction means), 12 ... Gas pipe (gas introduction means), 13 ... Heating means.

Claims (3)

A processing furnace, a transporting means for transporting a processing object so as to pass through the processing furnace, a gas introducing means for introducing a carbon-containing source gas into the processing furnace, and a heating means for heating the source gas, A carbon nanostructure growth CVD apparatus for growing a carbon nanostructure on a surface of a processing object passing through a processing chamber,
The transport means has a belt-like body on which the processing object is placed and travels at a predetermined speed, and the belt-like body allows a plurality of carbon nanostructures to grow on the placement surface side of the processing object. In what the opening is formed,
A mesh body is interposed between the strip and the object to be processed ,
The mesh body is formed by assembling a wire having an outer diameter smaller than the wire constituting the belt-like body,
The opening ratio of the mesh body, CVD apparatus for carbon nanostructure growth which is characterized in Rukoto is set in a range of 50 to 99.8%. The CVD apparatus for carbon nanostructure growth according to claim 1, wherein the belt-shaped body is constituted by a mesh belt.
The mesh body has pre SL CVD apparatus for carbon nanostructure growth which is characterized in that travel with the travel of the mesh belt. A method of manufacturing a 請 Motomeko 1 or claim 2 carbon nano structure using the CVD apparatus for carbon nanostructure growth according,
After stacking the belt-shaped body and the mesh body, a preparation step of placing the processing object on the mesh body;
The belt-like body and the mesh body are run in the processing furnace, and while passing through the processing furnace, the heated source gas is brought into contact with the surface of the processing object to grow the carbon nanostructure on the surface of the processing object. Growth process,
In the growth step, a first stage in which the carbon nanostructures that grow on the mounting surface side of the object to be processed are in contact with the wires constituting the mesh body, and the carbon nanostructures that are in contact with the wires further grow. And the carbon nanostructure manufacturing method characterized by growing a carbon nanostructure through the 2nd step of carrying | supporting a process target object with these grown carbon nanostructure.

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