JPS6041602B2 - Manufacturing method of fluorinated graphite - Google Patents

Description

[Detailed Description of the Invention] Fluorinated graphite has recently attracted attention as a new industrial material, and is used in various fields such as, for example, as an active material in high-energy batteries, as a solid lubricant, in lubricating paints, and in lubricating well girder plating. , the demand for it is rapidly increasing, and mass production is desired.

However, the manufacturing temperature of fluorinated graphite is as high as 200 to 600°C, depending on the carbon material used as the raw material, and the reaction time is as long as 5 to 10 hours, and equipment materials are also limited due to the corrosive nature of fluorine. receive.

Therefore, it is very important from an economic point of view to investigate a method by which fluorinated graphite can be easily produced at lower temperatures.
Conventionally, many methods have been proposed for producing fluorinated graphite at low temperatures and in high yields, such as using gases modified from carbon materials as raw materials.

The former category includes those using coking coal activated with ammonia gas or steam (Japanese Unexamined Patent Publication No. 51-3959).
7), but the disadvantage is that the conditions for performing these activation treatments are relatively high temperatures (900° C. or higher) and that activated carbon is expensive. The latter category also includes fluorine mixed with oxygen (adjustment is required; mixing more than necessary may cause rapid decomposition).
The inventors of the present invention have repeatedly conducted various studies on how to increase the reaction rate of any carbon material by simple treatment regardless of the raw material carbon material. C:F=1: at low temperature and high yield
Chemical formula (CF)O or (CF) with a composition of 2 to 2:1
) The present invention was completed by discovering that it is possible to produce high-purity fluorinated graphite represented by n.

The carbon material used in the present invention is effective for carbon materials that normally produce fluorinated graphite at temperatures of 200° C. or higher, such as natural graphite, artificial graphite, and petroleum coke.

According to research by the present inventors, highly reactive carbon materials such as activated carbon react rapidly when brought into contact with fluorine at high temperatures, resulting in severe decomposition. It became clear that it had to be changed, and it was already published in the diary journal (NO.8plO82~108den 197
8).

On the other hand, natural graphite, artificial graphite, petroleum coke, etc.
At temperatures below 200℃, there is almost no fluorination, so at 50℃
Fluorinated graphite is not produced below. For this reason, fluorinated graphite has been produced at temperatures of 200°C or higher. However, the present inventors have found that weight increases occur even at temperatures below 50° C. for these carbon materials, and nearly 10% of the carbon materials combine (react) with fluorine to form some kind of compound. That is, it has become clear that although fluorinated graphite does not occur at temperatures below 50°C, a reaction product in a transition state between fluorine and carbon is formed by contact with fluorine. Surprisingly, if this low-temperature fluorine-treated carbon material is used to react with fluorine at a temperature of 200°C or higher, the reaction rate will be faster and faster than when untreated carbon material is used. In an hour, fluorinated graphite can be produced. The lower limit of the temperature for this preliminary fluorine treatment is not particularly critical, but considering the effectiveness and economy, -10
It is around 0℃. In the present invention, it is preferable to treat the raw carbon material at 50°C or lower using fluorine gas for 0.5 to 2 plows, and the treatment method is to charge the raw carbon material into a closed container,
Any suitable method can be employed, such as a method in which fluorine gas is introduced for treatment, or a method in which raw carbon is charged into a fluidized bed and treated by being fluidized with fluorine gas.

In addition, although there are no particular restrictions on fluorination, from an operational point of view it is preferable to use atmospheric pressure or lower, existing production equipment may be used, and since fluorine, which is a constituent element of the product, is used, there is no effect on the purity of the product. There is no effect.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the scope of the present invention is not limited to the Examples. Examples 1 to 2, Comparative Example 1 A fluorine-resistant thermobalance was used as a reaction apparatus.

Natural graphite with an average particle size of 10 μm was used as the raw material carbon. 50 mg of this graphite was introduced into a thermobalance, introduced into the thermobalance from a fluorine cylinder, and fluorine treated under the following conditions while maintaining the fluorine pressure at 760 Hg.
The reaction temperature was maintained at 380°C. The time-weight increase curve at that time is shown in FIG. V1 no I~
^J/:C Unprocessed results are also shown.

Table 1 shows the generation time and fluorine content when these graphites are completely fluorinated. By fluorine treatment,
The reaction rate increases, and fluorinated graphite with a high fluorination rate can be easily obtained.

Examples 3-4, Comparative Example 2 The reaction apparatus was the same as in Example 1.

Petroleum coke with an average particle size of 15 μm was used as raw carbon, and it was treated with fluorine under the following conditions, and then treated with 15 C1 min.
The reaction temperature was maintained at 280°C. The time-weight increase curve at that time is shown in FIG. Raw results are also shown.

Table 2 shows the generation time and fluorine content until these graphites are completely fluorinated.

By performing the fluorination treatment, the reaction rate increases and high fluorinated graphite can be easily obtained. Example 5 The reactor consists of a nickel reactor with a diameter of 58T1Un1 and a height of 260TmIn and an external heater.

Graphite (average particle size: 20μ) 5y was placed in a reactor, the inside of the reactor was vacuum degassed, fluorine was introduced, and the pressure was kept at atmospheric pressure.
It was left at 20°C for 4 hours. Thereafter, the mixture was heated at 5° C. for 1 min, and the reaction temperature was maintained at 380° C. for an extended period of time. The fluorine content of the produced sample was 51.2%,
Graphite is fluorinated and the product is graphite fluoride (CF)n
It is. Comparative Example 3 The reactor and raw material graphite were the same as in Example 1.

Graphite 5y was placed in a reactor, vacuum degassed, and heated to 38
It was kept at 0°C.

Thereafter, fluorine was gradually added thereto, maintained at atmospheric pressure, and reacted for 2 hours. Although the fluorine content of the resulting sample was 47.9%, unreacted graphite still remained. Comparative Example 4 The reaction apparatus, raw material graphite, and reaction method were the same as in Example 3.
The fluorine content of the resulting sample, which was subjected to a three-turbidity reaction at 00C, was 50.0%, and the graphite was completely fluorinated.

[Brief explanation of the drawing]

FIGS. 1 and 2 show relationship curves of weight increase over time when the raw material graphite is subjected to preliminary fluorine treatment and the temperature is raised to cause a fluorination reaction.

Claims (1)

[Claims] 1. In a method for producing fluorinated graphite in which a carbon material and fluorine are reacted, the carbon material is treated with fluorine at a temperature of 50°C or lower, and then the reaction temperature is raised to perform a fluorination reaction at a temperature of 200°C or higher. A method for producing fluorinated graphite, characterized by: 2. The manufacturing method according to claim 1, wherein the fluorine treatment is performed at room temperature or lower for 0.5 to 24 hours.