JP3043573B2 - Carbon material having glassy carbon coating layer and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a carbon material having a glassy carbon coating layer and a method for producing the same.

[0002]

2. Description of the Related Art Carbon materials are materials having excellent heat resistance and chemical resistance, but their use is limited due to dust generation. Therefore, there is a demand for the development of a treatment method for suppressing the generation of dust of a carbon material. As one of the methods, a method of coating the surface of a carbon material with glassy carbon which is difficult to generate dust has been proposed.

[0003] Conventional methods of coating glassy carbon include:
Using a polymer compound (resin) or a pitch-like substance obtained by thermally decomposing it as a coating material, using a solution obtained by dissolving this in a solvent, applying it to the carbon material surface, and drying the solvent After that, it is a method of firing in an inert gas (for example, see Japanese Patent Publication No. 2-7915).

However, this method has the following drawbacks because it uses a solution obtained by dissolving the coating material in a solvent as described above.

[0005] In order to form a resin coating layer on the surface of a carbon material, several applications are required. When the pore diameter and the porosity of the carbon material are large, it becomes difficult to form the resin coating layer. Due to volatilization of the solvent remaining in the resin coating layer, defects such as cracks and cracks are likely to occur in the glassy carbon coating layer obtained by firing. It is difficult to uniformly coat the resin.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, has high hardness, can suppress dust generation, and has a uniform thickness of glassy carbon without generating defects such as cracks and cracks. An object of the present invention is to provide a carbon material having a coating layer and a simple production method thereof.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a resin formed in a film shape on a carbon material has been thermocompressed to form a resin coating layer on the carbon material surface. The present inventors have found that a carbon material having a glassy carbon coating layer can be manufactured by easily forming and curing and firing the same, and arrived at the present invention.

That is, according to the present invention, a carbonizable resin molded into a film having a thickness of 5 to 50 μm is heat-pressed to a carbon material, and the resin is cured at 100 to 200 ° C., and then heated under an inert gas atmosphere. Firing temperature 800 ° C or higher, heating rate 15 ° C /
The present invention provides a method for producing a carbon material having a glassy carbon coating layer, characterized in that the carbon material is fired under a condition of not more than minutes.

The resin used in the present invention is a resin that can be formed into a film, can be bonded to a carbon material by heat compression, and can be carbonized. Specifically, COPNA resin (polycyclic aromatic condensed compound), polyimide resin, vinyl chloride resin, vinyl acetate resin, polyvinyl alcohol resin,
Phenol resins and the like are exemplified.

The method of forming the resin into a film is not particularly limited, and for example, a method of passing the resin together with a release film between heating rolls can be used. On this occasion,
A solvent may be used for the purpose of reducing the viscosity of the resin.
This solvent can be removed as it passes between the heating rolls to a level that does not affect the manufacturing process or the final product.

The thickness of the film must be 5 to 50 μm. If the thickness of the film is less than 5 μm, the thickness of the finally obtained glassy carbon coating layer becomes thin, and the effect of suppressing dust generation by coating becomes low. . Film thickness is 50μ
If it exceeds m, defects such as cracks and cracks occur in the glassy carbon coating layer.

Next, the resin (resin film) molded into a film is heated and pressed on a carbon material. The thermocompression bonding is performed by, for example, pressing the film against the carbon material using a dryer or an electric iron.

Next, the resin is cured at a temperature of 100 to 220 ° C. in the air. Curing temperature below 100 ° C or 22
If the temperature exceeds 0 ° C., inconveniences such as cracks occur in the obtained glassy carbon coating layer.

Finally, the cured resin film is carbonized by baking to form a glassy carbon coating layer. The firing is performed in an atmosphere of an inert gas such as nitrogen gas.
The reaction is performed at a temperature of 0 ° C. or more and a temperature rising rate of 15 ° C./min or less. If the firing temperature is lower than 800 ° C., the temperature for carbonization is insufficient. On the other hand, if the heating rate exceeds 15 ° C./min, inconveniences such as cracks and cracks occur in the glassy carbon coating layer.

Thus, the carbon material having the glassy carbon coating layer of the present invention is obtained. This carbon material has such advantages that the glassy carbon coating layer has high hardness, can suppress dust generation, has excellent abrasion resistance, and is hardly peeled off from the carbon material.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Example 1 A COPNA resin (trade name: SK Resin SKR-N, manufactured by Sumikin Kako Co., Ltd.) was passed between rolls heated to 75 ° C.
A film having a thickness of 30 μm was obtained. This was processed into a plate using an electric iron heated to 170 ° C. and had a bulk specific gravity of 1.6.
Carbon material (trade name: ER-38, Nippon Carbon Co., Ltd.)
And cured at 200 ° C. in the air, and then heated to 1000 ° C. in a nitrogen gas atmosphere at a rate of 5 ° C./min and fired to obtain a carbon material having a glassy carbon coating layer. Obtained.

As shown in Table 1, the properties of the glassy carbon coating layer were good in appearance, almost no defects such as cracks and cracks were observed, and no dust generation was observed.

Example 2 A commercially available vinyl chloride resin film (thickness: 20 μm) was applied to a carbon material having a bulk density of 1.8 (trade name: EGF-264, manufactured by Nippon Carbon Co., Ltd.) using an electric iron heated to 150 ° C. And crimped. After curing this at 160 ° C in air,
In a nitrogen gas atmosphere, the temperature was raised to 1000 ° C. at a rate of 2 ° C./min, followed by firing to obtain a carbon material having a glassy carbon coating layer.

As shown in Table 1, the properties of the glassy carbon coating layer were good in appearance, no defects such as cracks and cracks were observed, and no dust generation was observed.

Example 3 The same amount of methanol was added to a phenolic resin (trade name: Bellpearl S-899, manufactured by Kanebo Co., Ltd.) to form a varnish, which was passed through a heating roll set at 80 ° C., and a 30 μm film was formed. I got This was pressed against the same carbon material as used in Example 2 with an electric iron heated to 120 ° C., cured in air at 210 ° C., and then dried under nitrogen gas atmosphere.
The temperature was raised to 00 ° C. at a rate of 10 ° C./min, followed by firing at 2000 ° C. to obtain a carbon material having a glassy carbon coating layer.

As shown in Table 1, the characteristics of the glassy carbon coating layer were good in appearance, no defects such as cracks and cracks were observed, and no dust generation was observed.

Comparative Example 1 A carbon material having a glassy carbon coating layer was obtained in the same manner as in Example 1 except that the thickness of the film in Example 1 was changed to 70 μm.

However, many cracks were observed in the glassy carbon coating layer as shown in Table 1.

Comparative Example 2 A carbon material having a glassy coating layer was obtained in the same manner as in Example 1 except that the curing temperature in Example 1 was changed to 250 ° C.

However, many cracks were observed in the glassy carbon coating layer as shown in Table 1.

Comparative Example 3 A carbon material having a glassy carbon coating layer was obtained in the same manner as in Example 1 except that the heating rate of firing in Example 1 was changed to 30 ° C./min.

However, many cracks were observed in the glassy carbon coating layer as shown in Table 1.

Comparative Example 4 20 g of the same COPNA resin as used in Example 1 was added to 1
It was dissolved in 00 g of chloroform to obtain a uniform solution. The same operation of applying and drying the same on the surface of the carbon material as used in Example 1 was repeated 5 times,
μm). This was fired in the same manner as in Example 1 to obtain a carbon material having a glassy carbon coating layer.

However, as shown in Table 1, a large number of cracks and cracks were observed on the entire surface of the glassy carbon coating layer.

[0031]

[Table 1]

[0032]

As described above, the manufacturing method of the present invention has the following effects. By controlling the thickness of the film, the thickness of the resin coating layer and the thickness of the finally obtained glassy carbon coating layer can be controlled. A resin coating layer can be formed on the carbon material surface by one treatment. A resin coating layer can be formed on the surface of a carbon material having a large pore diameter or porosity. A resin coating layer having a uniform thickness can be obtained.

The carbon material having the glassy carbon coating layer obtained in the present invention has the following effects. The glassy carbon coating layer has high hardness, can suppress dust generation, and has excellent wear resistance. Good adhesion between glassy carbon coating layer and carbon material,
There is no separation of both. The thermal expansion coefficient of the glassy carbon coating layer is 3.2 × 10 ^-6.
/ ° C., and the carbon material is 3 to 6 × 10 ⁻⁶ / ° C., so that the two are not separated by rapid temperature rise or rapid cooling. Gas and liquid impermeability of the glassy carbon coating layer is high.

The carbon material having the glassy carbon coating layer having such advantages can be applied to applications where conventional dusting carbon materials could not be developed, for example, to the field of semiconductors and foods.

Continuation of the front page (56) References JP-A-59-21512 (JP, A) JP-A-4-83779 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 41 / 80-41/91 C04B 35/52-35/54

Claims (2)

(57) [Claims] 1. A carbonizable resin molded into a film having a thickness of 5 to 50 μm is pressure-bonded to a carbon material by heating and pressing.
A method for producing a carbon material having a glassy carbon coating layer, wherein the resin is cured at 00 ° C. and then fired in an inert gas atmosphere at a firing temperature of 800 ° C. or more and a heating rate of 15 ° C./min or less. Method. 2. A carbon material having a glassy carbon coating layer obtained according to claim 1.