TWI494272B - Isotropic graphite material and method of producing the same - Google Patents

Description

Isotropic graphite material and method of producing the same

The present invention relates to an isotropic graphite material and a method of manufacturing the same, and more particularly to an isotropic graphite material having a surface intact and having no crack defects, and a method of manufacturing the same.

Isotropic graphite materials have high temperature resistance, electrical conductivity, thermal conductivity, light weight, corrosion resistance, etc., and have recently been widely used in metallurgy, machinery and semiconductor industries. Conventional isotropic graphite processes generally use coke as a raw material, which is mixed with coal tar pitch and binder and pulverized, then extruded into a green body in a mold, followed by non-oxidation. Carbonization under the conditions. Thereafter, the green body is further subjected to impregnation of the pitch and re-baking, and this is carried out a plurality of times, followed by graphitization to form an isotropic graphite material.

In recent years, the rapid development of technology has led to a rapid increase in demand for directional graphite materials with high density, high strength and good processing properties. However, the conventional isotropic graphite process is complicated. Therefore, in recent years, it has been developed to use directional directional graphite materials using mesocarbon microbeads (MCMBs) having self-sintering properties, which do not need to pass through. By impregnating asphalt and re-sintering to fill the holes, high-strength, high-density graphite carbon materials can be produced, which can be greatly improved. The mechanical properties of graphite have been improved, which also simplifies the complicated production process of isotropic graphite materials. The above-mentioned processes and materials can be found in related documents, such as U.S. Patent Nos. 5,525,276, 5,547,654, 5,609,800, 4,929,404, and Taiwan Patent Publication Nos. TW 326027, TW 379202, TW424079, etc. References.

However, the above process of the graphite material still has the following problems. For example, in the process of forming a green body by using mesocarbon microbeads, in the process of subsequent carbonization and graphitization, from room temperature (about 10 ° C to 40 ° C) to 600 ° C, in the green body Low-boiling substances, or small molecules derived from polycondensation or degradation reactions at high temperatures, will escape from the green body and cause internal stress in the green body, resulting in the surface of the subsequently obtained graphite carbon material. The cracks are even broken, and there is a problem that the green body is incomplete, and in the larger size of the green body, the phenomenon of cracking or cracking on the surface after carbonization and graphitization is more serious. Secondly, if the above process needs to be carbonized in a vacuum state (for example, as described in the above-mentioned Taiwan patent), the cost in mass production will be greatly increased. If, in order to avoid the problem of the escape of volatile components during carbonization and graphitization, the rate of temperature increase of the carbonization process is slowed down, which will make the carbonization process longer and more energy-intensive.

In view of the above, it is urgent to provide an isotropic graphite material and a method for manufacturing the same, which can effectively improve the surface crack defects or cracks of the graphite material obtained by the conventional process, and limit the scope of application thereof.

Accordingly, one aspect of the present invention provides a method for producing an isotropic graphite material by preheating mesocarbon microbeads in the presence of a protective atmosphere prior to the mesophase carbon microspheres being pulverized. The treatment can improve the phenomenon that cracks or cracks are likely to occur when the subsequent green body is carbonized, and further, after the graphitization treatment, a directional graphite material with complete and no crack defects is obtained.

Secondly, another aspect of the present invention provides an isotropic graphite material obtained by the above method, and the obtained isotropic graphite material has a complete surface and no crack defects, and has good mechanical properties. , thermal and electrical properties.

According to the above aspect of the invention, a method of producing an isotropic graphite material is proposed. In one embodiment, the directional graphite material is produced by preheating the mesocarbon microbeads at a temperature above 200 ° C in the presence of a first protective atmosphere.

In an example, the mesocarbon microbeads have a toluene insoluble component (hereinafter abbreviated as TI) and a quinoline insoluble component (hereinafter referred to as QI), and the difference between TI and QI can be, for example, 0.1 weight percent (wt%) to 4.0 wt%.

Next, the pre-heat treated mesocarbon microbeads are subjected to a pulverization treatment to form a powder raw material, wherein the powder raw material may have an average particle diameter of, for example, 1 μm to 15 μm.

Then, the powder raw material is molded by a cold equalizing method to form a green body.

Thereafter, the green body is carried out in the presence of a second protective atmosphere Carbonized to form a carbonized material. Then, the carbonized material is graphitized in the presence of a third protective atmosphere to form an isotropic graphite material. In an example, the surface of the isotropic graphite material obtained is complete and has no crack defects, and the difference of the thermal expansion coefficients of the X-axis, the Y-axis and the Z-axis of the directional graphite material is less than 10 %.

According to an embodiment of the present invention, the first protective atmosphere, the two protective atmosphere, and the third protective atmosphere may be the same or different, and the first protective atmosphere, the second protective atmosphere, and the third protective atmosphere may include, but are not limited to, nitrogen. Argon, helium or any combination of the above.

According to another aspect of the present invention, an isotropic graphite material is produced which is produced by the above-described method for producing an isotropic graphite material, wherein the obtained isotropic graphite material has a range of 1.75 g/cm ³ to 1.95. The density of g/cm ³ and the hardness of 50 to 90.

The use of the isotropic graphite material of the present invention and the method thereof, prior to the pulverization treatment of the mesophase carbon microsphere raw material, preheating the mesocarbon microbeads in the presence of a protective atmosphere to improve subsequent carbonization and The isotropic graphite material obtained after graphitization has a complete surface and no crack defects, and has better mechanical, thermal and electrical properties.

100‧‧‧ method

101‧‧‧Pre-heat treatment of mesocarbon microbeads in the presence of a protective atmosphere

103‧‧‧Steps of pulverizing the mesocarbon microbeads after preheating to form powder raw materials

105‧‧‧Steps of molding powder raw materials into green bodies by cold isostatic pressing

107‧‧‧Steps for carbonizing green bodies to form carbonized materials

109‧‧‧Steps of graphitizing carbonized materials to form isotropic graphite materials

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; Part of the flow chart of the manufacturing method.

As described above, the present invention provides an isotropic graphite material and a method for producing the same, which pre-heat treatment of mesocarbon microbeads in the presence of a protective atmosphere before the mesophase carbon microspheres are pulverized. The directional graphite material obtained after the subsequent carbonization and graphitization treatment can be improved to make the surface intact and free from crack defects.

In other words, the method for producing an isotropic graphite material of the present invention can be obtained by the following method. Please refer to FIG. 1 , which is a partial flow chart showing a method of manufacturing an isotropic graphite material according to an embodiment of the invention. In one embodiment, the method 100 can perform a pre-heat treatment of the mesocarbon microbeads in the presence of a protective atmosphere, such as a first protective atmosphere, as shown in step 101. In one example, the first protective atmosphere described above is nitrogen, argon, helium, and any combination thereof. In another example, the aforementioned first protective atmosphere is nitrogen.

The mesophase carbon microspheres may be commercially available products, and the invention is not particularly limited. It should be noted that, since the present invention produces an isotropic graphite material without adding any binder, in an exemplary embodiment, the mesophase carbon microspheres contain an appropriate amount of β-resin (β-resin). It has good self-sintering characteristics and can be made into high-density isotropic graphite materials after cold equalizing, carbonization and graphitization.

In general, the content of the β-resin is defined as the difference between the toluene-insoluble component (hereinafter abbreviated as TI) and the quinoline-insoluble component (hereinafter referred to as QI). In an example, the difference between TI and QI of the aforementioned mesocarbon microbeads may be, for example, From 0.1% by weight (wt%) to 4.0% by weight, the difference is preferably from 0.2% by weight to 4.0% by weight, more preferably from 0.4% by weight to 4.0% by weight.

Specific examples of the mesocarbon microbeads suitable for use in the present invention may be, for example, mesocarbon microbeads G or mesocarbon microbeads B-N1 manufactured by Sinosteel Carbon Chemical Co., Ltd., the basic data of which is in Table 1.

One of the features of the method of the present invention is that the mesocarbon microbeads are preheated at a temperature higher than 200 ° C and in the presence of a first protective atmosphere prior to the pulverization treatment, thereby reducing the mesocarbon microspheres. The content of low boiling substances. In an exemplary embodiment, the foregoing preheat treatment is carried out at 250 ° C to 450 ° C, and the preheat treatment time may be, for example, 3 hours to 24 hours, but the invention is not limited thereto.

It is explained that if the mesocarbon microbeads are subjected to the aforementioned pre-heat treatment at 200 ° C or lower, the low-boiling substances remain more, and the carbonized body obtained after the subsequent carbonization treatment is low-boiling substances. The breakage causes cracks or cracks, which causes the incompleteness of the blank. In addition, if the mesocarbon microbeads are preheated at a temperature higher than 450 ° C, the residual portion of the β-resin is too dry, the self-sintering property is poor, and the carbonization after the subsequent carbonization treatment The body is fragile, the yield is low, and the graphitization The mechanical properties of the graphite blocks are not good. However, if the mesocarbon microbeads are preheated at 250 ° C to 450 ° C, the powder raw material obtained by the subsequent pulverization treatment is further subjected to carbonization and graphitization to avoid release of a large amount of low boiling components, and Effectively improve the yield of isotropic graphite materials.

Next, as shown in step 103 of Fig. 1, the mesocarbon microbeads after the preliminary heat treatment in the above step 101 are subjected to a pulverization treatment to form a powder raw material. In one embodiment, the pulverizing treatment may pulverize commercially available mesocarbon microbeads using, for example, a commercially available ball mill pulverizing apparatus, a gas pulverizing apparatus, a jet pulverizing apparatus, or a high pressure homogenizing apparatus to form a commercially available mesocarbon microbead. The powder material having an average particle diameter (D ₅₀ ) of from 1 μm to 15 μm, however, the above-mentioned powder material preferably has an average particle diameter (D ₅₀ ) of from 3 μm to 12 μm.

Here, it is explained that the powder raw material of the present invention has an average particle diameter of from 1 μm to 15 μm, contributing to formation of a dense green body. If the average particle size of the powder raw material is too large, the formed green body tends to have large pores, thereby affecting the density of the directional carbonaceous material which is subsequently produced. If the average particle size of the powder raw material is too small, the time and cost of the pulverization step are increased.

Then, as shown in step 105 of Fig. 1, the powder raw material is molded into a green body by a cold equal pressure equalization method. In an illustration, the the cold etc. pressure law applying a pressure / cm ² of 500kg / cm ² to 3000kg of die above-described filling raw powder, wherein the pressure means the maximum molding pressure. In other examples, the process of cold pressing etc. can be applied to a ² pressure of 2500kg 1000kg / cm / cm ² to mold the above-described raw material powder filling.

Thereafter, as shown in step 107 of Fig. 1, the green body is subjected to carbonization treatment in the presence of a second protective atmosphere to form a carbonized material. In one example, the aforementioned second protective atmosphere is nitrogen, argon, helium, and any combination thereof. In another example, the aforementioned second protective atmosphere is nitrogen.

Then, as shown in step 109 of Fig. 1, the carbonized material is graphitized in the presence of a third protective atmosphere to form an isotropic graphite material. In one example, the third protective atmosphere is nitrogen, argon, helium, and any combination thereof. In another example, the aforementioned third protective atmosphere is argon. In other examples, the first protective atmosphere, the second protective atmosphere, and the third protective atmosphere may be the same or different.

After the carbonization treatment and the graphitization treatment described above, or after the graphitization treatment, the temperature reduction step is more selectively performed. It is stated that, between the foregoing carbonization treatment and graphitization treatment, the first natural temperature lowering step can be selectively performed, and the temperature of the aforementioned carbonized material is lowered to 25 without using any cooling equipment and from 45 hours to 50 hours. °C to 40 °C.

In addition, after the graphitization treatment, the second natural temperature lowering step can be selectively performed to lower the temperature of the aforementioned directional graphite material to 25 ° C to 40 ° C without using any cooling equipment. The first natural cooling step and/or the second natural cooling step are performed to make the obtained isotropic graphite material more dense and surface intact without crack defects.

It is worth mentioning that, since the mesophase carbon microspheres are preheated in the presence of a protective atmosphere before the mesophase carbon microsphere raw material is pulverized, the present invention effectively improves the subsequent carbonization and graphitization treatment. The surface of the directional graphite material is intact, so that it does not have crack defects or cracks, improves the yield, and has better mechanical, thermal and electrical properties. The method of the present invention also eliminates the conventional processes of impregnation, re-sintering, etc., to save manufacturing costs. Here, the term "isotropic graphite material" as used herein refers to a graphite material obtained by the above method, the surface of which is intact and free from crack defects, and the directional graphite materials are on the X-axis and the Y-axis. The degree of difference from either of the thermal expansion coefficients of the Z-axis is less than 10%, indicating that it has a preferred isotropic property. Secondly, these directional graphite materials have a density of 1.75 g/cm ³ to 1.95 g/cm ³ and a Shore hardness of 50 to 90. In other examples, the directional graphite material has a density of 1.84 g/cm ³ to 1.93 g/cm ³ and a Shore hardness of 58 to 85.

Since the method for manufacturing the isotropic graphite material of the present invention is not only environmentally friendly and energy-saving, and the obtained isotropic graphite material has better equi-directionality, the surface is completely free of crack defects, and the mechanical, thermal and electrical properties thereof are greatly improved, and further It is used to expand the scope of its industrial use and increase its economic value. For example, the isotactic graphite material obtained as described above can be applied to electric discharge machining, continuous casting, single crystal enamel crystal growth furnace, and the like.

The following examples are used to illustrate the application of the present invention, and are not intended to limit the present invention. Those skilled in the art can make various changes without departing from the spirit and scope of the present invention. Retouching.

Example 1

First, mesophase pitch carbon microspheres G (TI 99.0%, QI 98.6%, average particle size (D ₅₀ ) 24 μm; China Steel Carbon Chemical Co., Ltd.) were placed in a commercial atmosphere furnace. Nitrogen was used as a protective atmosphere and preheat treatment was carried out at a temperature of 300 ° C for 6 hours.

Thereafter, the pre-heat-treated mesophase pitch carbon microspheres G were pulverized by a gas-injection pulverizing apparatus (ALG-2, Lingguang Industrial Co., Ltd., Taiwan) to form a powder raw material. Thereafter, using a particle size analyzer ^{(Multisizer TM 3, Beckman Coulter,} Inc., USA) analysis of this raw material powder having an average particle diameter (D ₅₀₎ of about 8μm.

Next, about 863 g of the above powder raw material was filled in a cylindrical rubber mold (molar wall thickness: 4.0 mm) having an inner diameter of 100 mm, and the filling height of the pulverized powder in the mold was about 160 mm. After the mold is covered with a homogenous rubber cover and compacted, it is simply packaged (for example, tightly wound with an electrical tape) to avoid contamination of the pressurized liquid in the mold during cold equalizing operation.

Then, the mold filled with the pulverized powder is placed in a cold equalizing device (wet cold equalizing machine manufactured by Jingfeng Hydraulic Co., Ltd., a molding chamber having a diameter of 130 mm, a height of 400 mm, and a maximum molding pressure of 2,500 kg/cm ² ). Pressurize to about 1,400 kg/cm ² and maintain at this pressure for about 5 minutes. Thereafter, the pressure was released to normal pressure, and the press-formed cylindrical green body was taken out from the rubber mold. Thus, the green body produced had a diameter of 79 mm and a length of 134 mm.

Next, the green body was placed in a commercial atmosphere furnace, and carbonization was carried out in the case where nitrogen gas was used as a protective atmosphere to form a carbonized material. Thereafter, the first natural cooling step is performed, and the furnace body is naturally cooled to room temperature (about 10 ° C to 40 ° C) in about 48 hours without using any cooling equipment, and the carbonized material obtained by the carbonization treatment is surfaced. Complete, crack-free defects, measured to have a density of 1.73 g/cm ³ .

Then, the foregoing carbonized material is placed in a vacuum high temperature furnace (Vacuum Furnace Type 45, Centorr Vacuum Industries, Inc.), and in the presence of a second protective atmosphere such as argon, at a temperature increase rate of 6.7 ° C/min, the foregoing The carbonized material was heated from room temperature (about 10 ° C to 40 ° C) to 2750 ° C and held at a temperature for 1 hour for graphitization. Thereafter, a second natural cooling step is performed to naturally cool the furnace body to near room temperature (about 10 ° C to 40 ° C) without using any cooling equipment, wherein the graphite material obtained is an isotropic graphite material. The isotropic graphite material obtained in Example 1 has a density of 1.85 g/cm ³ and a Shore hardness of 58, the surface of which is intact and has no crack defects, and the difference in thermal expansion coefficients of the directional graphite materials in all directions. The degree is less than 10% (the thermal expansion coefficients in the X, Y, and Z directions are both 5.7×10 ^-6 K ^-1 to 6.0×10 ^-6 K ^-1 ), that is, they have good isotropic properties.

The isotropic graphite material obtained in Example 1 was further tested for its flexural strength, compressive strength, and electrical resistivity. The method for detecting the details is as described later, and the results are shown in Table 2.

Examples 2 to 6 and Comparative Examples 1 to 3

In Examples 2 to 6 and Comparative Examples 1 to 3, a pre-heat treatment, a pulverization treatment, a cold isostatic pressing, a carbonization, and a graphitization treatment were carried out in the same manner as in Example 1. The preheat treatment temperatures of Examples 2 to 3 and Comparative Example 2 were different from those of Example 1, while Comparative Example 1 and Comparative Example 3 were not subjected to preheat treatment, and the process conditions were also listed in Table 2.

Evaluate the effectiveness of carbonized materials and isotropic graphite materials Surface appearance

The carbonized materials obtained in Examples 1 to 6 and the graphite materials obtained in Examples 1, 4, and 5, and the carbonized materials obtained in Comparative Examples 1 to 3 were further visually observed for the surface integrity, and Standard evaluation, the results are shown in Table 2: ○: Surface integrity and no crack defects

×: The surface is incomplete and has cracks or cracks.

It can be seen from the second table that since the first embodiment to the sixth embodiment pre-heat treatment of the mesophase pitch carbon microspheres in the presence of a protective atmosphere before the pulverization treatment, the carbonization treatment and the graphitization treatment, the examples The carbonized material obtained in 1 to 6 and the surface of the isotropic graphite material obtained in Examples 1, 4, and 5 were completely free of crack defects. In comparison, the carbonized materials obtained in Comparative Examples 1 to 3 had incomplete surfaces and cracks. Next, since the carbonized materials prepared in Comparative Examples 1 to 3 were broken and incomplete, further graphitization could not be performed to produce a complete isotropic graphite material.

2. Mechanical strength

The carbonized materials obtained in Examples 1 to 6 and the graphite materials obtained in Examples 1, 4, and 5, and the carbonized materials obtained in Comparative Examples 1 to 3 were evaluated for mechanical strength, and the commercial use was used. Shore hardness tester (Shore Hardness Tester, Type D, Sato Seiki Co., Japan) measures Shore hardness (Shore hardness; Hs) using ASTM (American Society for Testing and Materials) C651 test method and The flexural strength was measured by a Sintech 10/GL material testing machine (MTS Test Systems Co., U.S.A.), and the compressive strength was measured using a test method of ASTM C695 and a Sintech 10/GL material testing machine, and the results are shown in Table 2.

It can be seen from the second table that since the first embodiment to the sixth embodiment pre-heat treatment of the mesophase pitch carbon microspheres in the presence of a protective atmosphere before the pulverization treatment, the carbonization treatment and the graphitization treatment, the examples The surface of the isotropic graphite material obtained in 1, 4, and 5 is complete without crack defects, and has a Shore hardness of 56 to 68, a flexural strength of 29 MPa to 47 MPa, and a compressive strength of 68 MPa to 107 MPa.

After the carbonization treatment of the process conditions of the above comparative examples, the surface of the carbonized material body produced has cracks, that is, the complete carbonized material cannot be produced; and thus the complete isotropic graphite can not be further formed by graphitization. material. Comparing with Examples 1 to 6, the reason why Comparative Example 1 and Comparative Example 3 could not produce a complete graphite material was that the mesocarbon microbeads were not preheated before the pulverization treatment; The reason why the complete graphite material could not be obtained in Example 2 was that the temperature of the pre-heat treatment of the mesocarbon microbeads before the pulverization treatment was not in the temperature range of more than 200 ° C and less than or equal to 450 ° C.

3. Thermal and electrical properties

Furthermore, the isotropic graphite materials obtained in Examples 1, 4, and 5 were evaluated for thermal and electrical properties, and the thermal conductivity and thermal expansion coefficient were measured by ASTM C714 and ASTM E228, and the test method of ASTM C611 was utilized. Measuring the resistivity, the results are shown in Table 2. Show.

It can be seen from the second table that the isotropic graphite materials obtained in Examples 1, 4, and 5 have a heat transfer coefficient of 68 W/mK to 76 W/mK and a thermal expansion coefficient of 5.7×10 ^-6 /K to 6.5×10 ^{− 6} / K, resistivity 6.6 μ Ωm to 7.3 μ Ωm.

Next, as can be seen from the results of the second table, in Examples 1 to 6, pre-heat treatment of the mesocarbon microbeads in the presence of a protective atmosphere prior to the pulverization treatment can improve the subsequent carbonation and graphitization treatment. The directional graphite material has a complete surface and no crack defects, and has better mechanical, thermal and electrical properties, so that the object of the present invention can be achieved.

However, it should be added here that the isotropic graphite material of the present invention and the method for producing the same can also be carried out using other mesocarbon microbeads or other reaction conditions, etc., which is any one of ordinary skill in the art to which the present invention pertains. Well known, so I will not repeat them.

It can be seen from the above embodiments of the present invention that the isotropic graphite material of the present invention and the method for producing the same have the advantages that the mesocarbon microbeads are preheated in the presence of a protective atmosphere before the mesophase carbon microspheres are subjected to the pulverization treatment. The treatment can improve the surface integrity of the directional graphite material obtained by the subsequent carbonization and graphitization treatment without crack defects, and has better mechanical, thermal and electrical properties, thereby increasing the industrial application range and improving its economic value, for example, It can be applied to electric discharge machining, continuous casting, single crystal crucible furnace.

While the invention has been described above in terms of several embodiments, it is not intended to limit the scope of the invention, and the invention may be practiced in various embodiments without departing from the spirit and scope of the invention. more The scope of protection of the present invention is defined by the scope of the appended claims.

100‧‧‧ method

101‧‧‧Pre-heat treatment of mesocarbon microbeads in the presence of a protective atmosphere

103‧‧‧Steps of pulverizing the mesocarbon microbeads after preheating to form powder raw materials

105‧‧‧Steps of molding powder raw materials into green bodies by cold isostatic pressing

107‧‧‧Steps for carbonizing green bodies to form carbonized materials

109‧‧‧Steps of graphitizing carbonized materials to form isotropic graphite materials

Claims (10)

A method for producing an isotropic graphite material, comprising: preheating a mesophase carbon microsphere at 250 ° C to 450 ° C in the presence of a first protective atmosphere, wherein the mesocarbon microbead has a toluene-insoluble component (TI) and a quinoline-insoluble component (QI), and the difference between the TI and the QI is 0.1% by weight (wt%) to 4.0% by weight; the mesophase carbon microparticles after the pre-heat treatment The ball is subjected to a pulverization treatment to form a powder raw material, wherein one of the powder raw materials has an average particle diameter of from 1 μm to 15 μm; the powder raw material is molded by a cold equal equalization method to form a green body; The green body is subjected to a carbonization treatment in the presence of a protective atmosphere to form a carbonized material; and the carbonized material is subjected to a graphitization treatment in the presence of a third protective atmosphere to form the directional graphite material. Wherein one of the directional graphite materials has a surface that is intact and has no crack defects, and the difference in thermal expansion coefficients of the X-axis, the Y-axis and the Z-axis of the directional graphite material is less than 10%. The method for producing an isotropic graphite material according to claim 1, wherein the first protective atmosphere, the second protective atmosphere, and the third protective atmosphere are the same or different, and the first protective atmosphere, the first protective atmosphere The second protective atmosphere and the third protective atmosphere are nitrogen, argon, helium or any combination thereof. The method for producing an isotropic graphite material according to claim 1, wherein the first protective atmosphere, the second protective atmosphere, and the third protective atmosphere are the same or different. The method for producing an isotropic graphite material according to claim 1, wherein the first protective atmosphere and the second protective atmosphere are nitrogen. The method for producing an isotropic graphite material according to claim 1, wherein the third protective atmosphere is argon. The method for producing an isotropic graphite material according to claim 1, wherein the difference between the TI component and the QI component is from 0.2 wt% to 4.0 wt%. The method for producing an isotropic graphite material according to claim 1, wherein the difference between the TI component and the QI component is from 0.4 wt% to 4.0 wt%. The method for producing an isotropic graphite material according to claim 1, wherein the average particle diameter of the powder raw material is 7 μm or 8 μm. The method of producing a grain oriented graphite material and the like of the patent scope item 1, wherein the cold press method etc. based applying a pressure 1400 kg / cm ² or 2000kg / cm ² of the raw material powder to form the green body . An isotropic graphite material obtained by the method of any one of claim 1 to claim 9, wherein the directional graphite material has 1.85 g/cm ³ to A density of 1.9 g/cm ³ and a hardness of 56 to 68.