JPS58120510A - Method to precipitate pyrolytic carbon - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improved method for depositing pyrolytic carbon on a substrate.

In recent years, pyrolytic carbon has been used as a conventional sinter molded carbon material.
It has attracted attention as a material with new characteristics, and has been developed using various manufacturing methods.
Development research on its uses is being conducted.

Among them, Mr. Inutani Sugibe uses halogenated carbon hydrogen as a raw material to precipitate pyrolytic carbon! ;00-10
It is attracting attention because carbon can be deposited at a practical rate at a temperature of 00°C.

On the other hand, with regard to applications, we target ready-made materials and shapes such as ceramics, metals, and carbonaceous materials as base materials for carbon precipitation, and coat the surface of this material with carbon to modify the function of the material. It is thought that the precipitated layer can be taken out individually and used as a new material, and used for various purposes in the form of a single substance or a composite, and some of them are at the stage of practical application. For example, it is applied to biological materials, spacecraft materials, mechanical materials, electrodes, etc.

In these applications, the size of the base material on which carbon is deposited ranges from extremely small, on the order of a few digits, to quite large, and its shape also varies from simple to complex. be.

On the other hand, in the case of precipitation of pyrolytic carbon, according to the conventional method, 1
A high temperature of SOO° C. or higher is required, and even the above-mentioned low-temperature pyrolysis method requires a high temperature of SOO° C. or higher. The essence of this reaction is that carbon deposition takes place in the gas phase, and this combined with high-temperature treatment makes it possible to process many substrates at once in the same reactor, or to process complex shapes. The thing is,
In particular, it has been extremely difficult industrially to ensure product uniformity.

The present invention aims to solve the above-mentioned limitations and provide a method for processing a large number of substrates at once in the same reactor to obtain products of uniform quality. The gist is that in a method of heating a base material and depositing pyrolytic carbon on the base material while flowing a raw material gas for depositing pyrolytic carbon, a plurality of base materials are supported in multiple stages in a reactor. , a method for thermally depositing carbon on a substrate, characterized in that a raw material gas is simultaneously supplied to each of the above-mentioned multiple stages via branch pipes.

The present invention will now be explained in detail in conjunction with the accompanying drawings, which show an apparatus for carrying out the method of the present invention.

FIG. 1 is a schematic longitudinal sectional front view of an example of an apparatus for implementing the method of the present invention, and FIG. 2 is a schematic perspective view of an example of a frame for a base material installed in a reactor of this apparatus.

In the figure, l is the reactor main body, C is an induction coil for heating, 3 is a mount for the base material, ri is a support for the mount 3, S is the base material, 6 is an introduction pipe for raw material gas to precipitate carbon, 6 '' is the source gas branch pipe, 7 is the gas discharge pipe, g is the thermocouple, wa is the support of the frame, IO
is a through hole provided in the frame 3, and ll is a cut through which a branch pipe is passed.

Although the reactor main body l is not shown, it is preferable to provide a cooling jacket and cool it by passing water through it during the reaction process. In addition, the raw material gas introduction pipe 6 and branch pipe 6' may be a single pipe, but
It is best to use double pipes to pass a refrigerant such as water.

The support means for the pedestal 3 is omitted in FIG. 1 to avoid complicating the drawing, but for example, as shown in FIG. If this is removably installed on the support stand, it will be convenient to take it out from the reactor main body during repairs. A large number of through holes are provided in the pedestal 3 to improve gas circulation.

Although the pedestal 3 shown in the figure has three stages, the number of stages can be increased or decreased as desired. Then, the base material S is placed on each mount 3, and the base material S is heated to a desired temperature by an induction coil coil, and at the same time, raw material gas is supplied from the temple entrance. The raw material gas comes into contact with the base material on each mount through the branch pipe 6', and deposits carbon on the base material. Since the base material is in contact with the raw material gas from the branch pipe 6' branching out for each stage, it is always treated with unused raw material gas, and therefore the base material on the frame of any stage is always kept at a constant level. undergoes uniform carbon deposition.

When increasing the number of stages of the pedestal 3, the large induction coil equipment for heating becomes ◆ correspondingly.
777993, JP-A No. 56-1.9270), there is a method of gradually moving the heating zone, for example, by using a small induction coil and using appropriate mechanical means to effectively react from the downstream side of the raw material gas flow. If the heating is carried out by gradually moving it along the body of the vessel, it is possible to avoid making the equipment too large.

Note that heating is not limited to the induction heating method, and other heating methods may be employed.

The base material to which the method of the present invention is applied is a carbon material,
Glass, ceramics, various single crystals, etc. retain their original shape without melting or decomposing at the carbon precipitation temperature.
Any solid material may be used as long as it can precipitate the desired pyrolytic carbon under predetermined conditions. The shape of the base material may be block, pipe, rod, plate, powder, granule, fiber, felt, or other complex shapes.
Both are possible.

The carbon deposition conditions employed in the method of the present invention, that is, the type of raw material gas, concentration, flow rate, heating method, deposition temperature, time, etc., may be any conventionally known conditions, and are appropriately selected from among them depending on the purpose. be done. ``Generally, hydrocarbons, halogenated hydrocarbons, and halogen-containing hydrocarbons are used as the raw material gas, and the heating temperature is SOO to 3000°C. However, the low-temperature pyrolysis method using the above-mentioned halogenated hydrocarbon as the raw material gas is preferred from the viewpoint of ease of selection of reactor material, operability, and ease of precipitation.

As described above, according to the method of the present invention, pyrolytic carbon can be precipitated industrially very advantageously. In other words, in the conventional method, the base material is placed in a reactor isolated from the outside world, and pyrolytic carbon is precipitated on the sulfur material-F by heating the entire base material while supplying raw material gas to this reactor. .

According to this conventional method, when carbon is deposited on a plurality of base materials, as the number of base materials increases, it is unavoidable that the reactor and eventually the heating device become large. In addition, as the number of substrates to be treated increases and the reactor becomes larger, the concentration, composition, flow rate, etc. of the raw material gas change locally within the reactor, resulting in changes in the quality of the pyrolytic carbon that precipitates. Differences and differences in deposition rate are inevitable, and it is technically extremely difficult to perform deposition on a large number of substrates at high temperatures at the same time under the same conditions.

On the other hand, in the method of the present invention, the substrates are installed in multiple stages along the flow of the reactant gas, so the space in the reactor is effectively utilized, so there is no need to make the heating device particularly large.

Furthermore, if the base material is simply installed in multiple stages and the raw material gas is introduced from one end, the effective gas component to be thermally decomposed decreases in the downstream region of the gas, making it possible to deposit uniform pyrolytic carbon in the upstream and downstream regions. become unable. According to the method of the present invention, even if the base material is installed in multiple stages, the raw material gas is supplied close to the base material through the branch pipes, so that even the downstream region comes into contact with undecomposed raw material gas, resulting in uniform thermal decomposition. Carbon can be precipitated.

Next, the present invention will be explained in detail.

Example 1 Using the device shown in the attached drawing (3 stages of mounts), the inner diameter was 30 mm.
3 graphite crucibles were placed on each stage at a depth of 1, 2-dichloroethylene was used as the raw material gas, the gas flow rate was 7.117 minutes, and the gas concentration was 3 gi.
% (in argon gas) and heating ml #70θ°C to deposit pyrolytic carbon to a thickness of 1θ0μ on the entire surface of the crucible except for the outer bottom surface in contact with the pedestal.

The state of carbon deposition in the obtained crucible was uniform in each stage. However, the pedestal had seven stages, and the flow rate of the raw material supply nozzle to each stage could be adjusted, and the six-conductor heating coil had the above-mentioned characteristics. Gansho 3 Hiro-/l'l tag 3 (Tokukaisho!; A-A9
As described in the specification, a type of gradual movement from the bottom to the top was used. Three graphite crucibles (inner diameter 30 rran 1 depth/jm) were placed on each stand, and carbon was precipitated under the same conditions as in Example. However, the induction coil is moved to the gas upstream side at a speed of 1cm7, and the raw material supply to each stage is adjusted according to the movement of the induction coil, and the raw material is heated by the induction coil. Flow rate '1.
/l/min.

The state of carbon precipitation in the obtained product was examined, and it was found to be uniform in each stage.

What has been explained above, shown in the drawings, and given in the examples are typical examples to help understand the present invention, and the present invention is not limited to these examples, but within the gist of the invention. Other changes and modifications may be made.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional front view of an example of an apparatus for carrying out the method of the present invention, and FIG. 2 is a schematic perspective view of an example of a frame for a base material installed in the apparatus of FIG. 12. In the figure, l is the reactor main body, C is the induction coil, 3 is the base material frame, left is the base material, 6 is the raw material gas introduction pipe, 6' is the raw material gas branch pipe, and 7 is the gas discharge pipe. . Applicant Kaoru Mitsubishi Chemical Industries, Ltd. 1 Figure 2

Claims (1)

[Claims] In a method of heating a base material to deposit pyrolytic carbon on the base material while flowing a raw material gas that deposits pyrolytic carbon,
A method for depositing pyrolytic carbon on a substrate, characterized by supporting a plurality of substrates in multiple stages in a reactor, and simultaneously supplying raw material gas to each of the multiple stages via branch pipes.