JPS6025364B2 - Method for producing raw material for high-density carbon material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a raw material for high-density carbon materials, and in particular, optically anisotropic small spheres obtained by heat-treating coal tar pitch and solvent fractionation are heated at 200 °C in an inert atmosphere. The present invention relates to a method for producing a raw material for a high-density carbon material, which is held at a temperature of ~45 mm, then molded, fired, and graphitized without using a binder.

Raw materials for high-density carbon materials are used for electrochemical purposes such as electrodes for electrical discharge machining, electrical purposes such as current collectors, metallurgical purposes such as lanterns and boat materials, mechanical purposes such as seal rings, and nuclear reactor materials. etc., mastery
It has been widely used and further development is underway. Therefore, in the conventional method for producing raw materials for high-density carbon materials using such optically anisotropic small spheres, petroleum-based heavy oil, coal tar pitch, etc.
optically anisotropic spherules produced by heat treatment at a temperature of C;
That is, it was carried out by separating the spherulites with a solvent.

The carbon material raw material thus obtained, that is, the above-mentioned spherulites, is then molded, fired, and then graphitized to produce a final product. However, in such conventional methods, a large amount of solvent is used in the step of separating the spherulites,
The solvent must be separated many times.

Moreover, the spherulites obtained in this way still tend to have some residual pitch (e.g. 8 resin) and solvent, and molded products made from this raw material are subject to residual pitch during the firing process. (For example, 8 resin, etc.) and solvents can cause cracking and blistering phenomena, making it difficult to obtain good products, and this poses considerable problems as an industrial manufacturing method. In view of the above-mentioned drawbacks, the present inventors conducted extensive research into a method for producing a raw material for high-density carbon materials from the spherulites, and found that the spherulites were separated at 200 to 4,500 C in an inert atmosphere after solvent fractionation.
We have found a method for producing a raw material for high-density carbon material, which produces excellent results that do not cause cracking or blistering in the competitive formation process after starch firing at a temperature of .

That is, the present invention has a coal tar pitch of 350 to 5
After heat treatment at a temperature of 0,000 °C and solvent separation of the optically anisotropic microspheres produced in the heat treatment process together with the B component in the pitch, the optically anisotropic microspheres with the solvent and three components remaining. and then an additional 200 min in an inert atmosphere.
This is a method for producing a raw material for high-density carbon material, which is produced at a temperature of ~45 pi.

To explain in more detail, coal tar pitch is 350
A heat treatment is performed at a temperature of ~500° C. to generate intermediate phase spherulites in the liquid phase (pitch), which are fractionated with a solvent and separated in a furnace to obtain spherulites.

The thus obtained spherulites contain a considerable amount of pitch (e.g. 8
This is then burned in an inert atmosphere at a temperature of 200 to 450 pm for 2 to 1 hour to remove the vertebrates remaining in the spherulites, and at the same time. Converts components such as 8 components into quinoline insoluble components (QI). As a result, a spherulite-fired product having B1 (benzene insoluble content) with a small amount of y component and B component and QI of approximately constant values is obtained. This fired product can then be shaped, fired, and graphitized to produce a high-density carbon material.

Since the above-mentioned crotch-fired product has very few low-boiling point components, good results can be obtained without cracking or blistering during the firing process due to the presence of these components. It becomes possible to manufacture materials. What should be noted is that in the firing process, there is a firing temperature between 200 and 45,000 that can maximize the density of the raw material for carbon material obtained by firing, and this temperature varies depending on the type of coal tar pitch and The value is unique depending on the manufacturing conditions of the spherulites, and the more the spherulites contain the eight components, the higher the density of carbon material can be obtained by firing the spherulites in an inert atmosphere. In addition, the searing temperature in the searing process is 200℃.
When the temperature is lower than ℃, there is sufficient Q from volatile components such as luminescence and three components.
No effect is obtained because I is not generated, and on the other hand, 450
If it exceeds 00, the caking property of the lamp product will be lost, resulting in the disadvantage that it will not be possible to mold it in the subsequent molding process.

In this way, the present invention produces spherulites obtained by heat-treating coal tar pitch under an inert atmosphere.
By firing the shrimp at a temperature of , the pitch (e.g., 8 resin) remaining in the ball product and the volatile components caused by the solvent are evaporated, and QI is created by polycondensation of the three components, resulting in excellent moldability. This is a method for producing spherulite that does not cause cracking or blistering during the firing process and provides a carbon material with higher density.

This method not only eliminates the cracking and blistering phenomena seen in conventional methods during the firing process, but also simplifies solvent separation, makes it possible to produce carbon materials that are economically cheaper and have even higher density than conventional products. It is something. The effects and fields of application of the present invention are as follows.

In other words, according to the conventional method, even if the solvent separation operation is repeated in an attempt to prevent cracking and blistering during the firing process caused by the low-boiling point content and solvent remaining in the spherulites,
Such low boiling point oil cannot be completely removed, and there is a high probability that cracks and blisters will occur during firing.

However, according to the method of the present invention, 20
A shrimp competition treatment is performed at a temperature of 0 to 450 qo to remove low boiling point pitch components (e.g. 8 resin) remaining in the spherulites and low brightness components due to solvents, and evaluate the properties of the raw coal tar pitch and the spherulite properties. By selecting manufacturing conditions and suitable firing conditions, fired products and graphitized products with the highest density can be obtained.

In addition, since it is possible to adjust the high density using shrimp phosphorus, compared to the conventional method of controlling the high density of carbon materials using only molding pressure, it is possible to control the high density of carbon materials by adjusting the starch conditions and molding pressure described above. By arbitrarily and appropriately combining these, it becomes possible to easily obtain a carbon material having a wider range of physical properties, and the uses of the carbon material can be further expanded. Furthermore, according to the present invention, it has been surprisingly revealed that the more a-component-containing spherulites are subjected to an appropriate firing treatment, the more dense the carbon material can be obtained.
As a result of converting the components into QI and effectively using them as carbon materials, the yield of raw materials for carbon materials mainly consisting of spherulites compared to raw material coal tar pitch was significantly improved.

The same applies to spherulites using petroleum heavy oil as a starting material. Next, examples will be further described.

Example 1 Spherulites A and B containing 6.6% by weight and 3.5% by weight of component B, respectively, were calcined in an inert atmosphere for 2 hours to obtain a spherulite.

The temperature of each shrimp competition was between 250 and 65,000 at intervals of 100 oo. An example of the analysis value of Shuba-yaki products is 35,000.
Table 1 shows the results of the cypress moth. In this Example 1, not performing shrimp roasting means that after extraction, after washing with acetone,
It is natural that the vacuum drying is carried out for 3 hours. Table 1: 350°C beating 1, analysis value of the product For this ceramic-fired product and the raw material spherulites A and B that are not phosphorized, a cylindrical mold with a diameter of 5 m2 was used, and 1.5 ton/you The molded product was press-molded at a pressure of 2,000 mm/h, and then heated to 1,000 oo degrees at a heating rate of 2,000 mm/h, and then maintained at this temperature for 2 hours to obtain a fired product, which was graphitized at a temperature of 260,000 mm.

Figure 1 shows high density, Figure 2 shows bending strength, Figure 3 shows the relationship between the characteristic values measured for the fired products and graphitized products obtained in this way and the temperature of the shrimp. shows the specific resistance.

As is clear from Fig. 1, the highest density is shown at 3500° for the material made from A, which contains many 8 components, and 250 CO for the material made from B, which contains less 8 components. In addition, the material made from A, which contains many 8 components, exhibited higher density.

In addition, all of the shrimp-fired products obtained at a firing temperature of 250 to 4,500C had good formability and had no cracks or blisters during firing, but side-fired products of 500C or higher The viscosity decreased and molding became difficult, and a good molded product could not be obtained, and firing and graphitization could not be performed. On the other hand, when raw materials A and B were fired without being phosphoroused, there was a high probability that cracks and blisters would occur.

Example 2 8 ingredients were mixed into 27. Using spherulite C containing $% by weight as a raw material, shrimp competition products were molded in the same manner as in Example 1, in which this C and this C were competed for one feeding time at a temperature of 35,000 °C in an inert atmosphere. , fired.

As a result, as shown in Figure 5 a and b, the product had a bulk density of 1.73 mm/ground without cracks or blisters, and a bending strength of 960 k.
Although a good fired product having a 9/2 degree of heat was obtained, cracks and blisters occurred in the product from C, which was not subjected to cross-firing, as shown in FIGS. 6a and 6b.

The analytical values of the roasted product were as shown in Table 2.

Table 2 350,℃ ■Analysis value of acid phosphorus M As mentioned in this Example 2, not performing phosphorus means that after extraction, washing with acetone, drying under reduced pressure at 90oo for 3 hours is natural. It is.

Example 3 Using spherulites A, B, D, E, and F, each containing different amounts of eight components, which were trial-produced from the same raw material coal tar pitch, as raw materials, molded and fired products were produced for each raw material in an inert atmosphere. Roasting was carried out under optimal shrimp scale conditions that gave the highest bulk density.

Next, each of the obtained crotch products was molded and fired in the same manner as in Example 1, and a good fired product was obtained without any cracking or blistering phenomena during firing.

FIG. 4 shows the relationship between the high density of the fired product thus obtained and the content of eight components in the raw material spherulites. That is, in FIG. 4, the horizontal axis represents the amount of 8-resin before dawn, and the vertical axis represents the bulk density of the fired product. Symbols A, B, C, D, E in the diagram
and F indicate the type of raw material spherulite corresponding to the fired product, and the numerical values indicate the three component contents of the raw material spherulite. As is clear from Figure 4, the higher the content of the eight components in the raw material spherulite, the higher the bulk density of the fired product obtained by molding and firing after the shrimp scale treatment. It is found that it is preferable as a raw material for raw materials.

In addition, in the following Table 3, raw material D (B component 4.6% by weight)
, shows the analytical values of raw material E (three components 14.7% by weight) after dawn.

Table-3 Analysis values of Tonoyaki products

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between temperature and high density for fired products and graphitized products in Example 1 of the present invention, and FIG.
Figure 3 is a diagram showing the relationship between crotch temperature and bending strength, Figure 3 is a diagram showing the relationship between phosphorus temperature and specific resistance, and Figure 4 is a diagram showing the relationship between spherulite temperature and specific resistance. A diagram showing the relationship between the content of 8 components and the high density of the fired product after baking, FIGS. plan and side views, respectively;
6a and 6b are a plan view and a side view, respectively, showing a fired product made from raw material spherulites that do not undergo the aging process, for comparison with FIG. 5. Figure 1 Figure 2 Figure 3 Figure 5 Figure 4 Figure 6

Claims (1)

[Claims] 1 Coal tar pitch is heat-treated at a temperature of 350 to 500°C, and after the optically anisotropic spherules generated in the heat treatment process are separated from the solvent together with the β component in the pitch, the solvent and β component remain. A method for producing a raw material for a high-density carbon material, characterized in that the optically anisotropic small spheres are then further baked at a temperature of 200 to 450°C in an inert atmosphere.