JPS60191012A - Method and apparatus for manufacturing high-density carbonaceous material - Google Patents

Abstract

PURPOSE:To obtain the titled carbonaceous material which is isotropic and large-sized and has excellent strength and resistance to corrosion by inserting a specified capsule wherein a carbonaceous molded body is enclosed into a high-pressure vessel, controlling the external pressure of the capsule to the pressure higher than the internal pressure, and calcining. CONSTITUTION:A molded body 13 consisting of a mixture of a carbonaceous filler material such as carbon fiber and an organic material binder such as tar pitch are melted and enclosed in a metallic H2-permeable or H2-occlusive capsule 12 equipped with an atmosphere regulating tube 14 wherein a hardly sintering ceramic powder 14' is packed so that the gas may be passed through. The capsule is inserted into a high- pressure vessel 1, and heated with heating bodies 4 and 4'. While the indicated values of pressure gauges 19 and 20 which are provided to a pressure medium gas and the pressure system in the capsule are compared, the pressure is increased through a pressure medium gas introducing hole 8 by operating a compressor 18 when the internal pressure of the capsule is increased due to the generation of decomposed gases resulting from calcination. Or the pressure is lowered by opening a valve 22 and releasing the internal pressure to control the pressure of the pressure medium gas to the pressure higher than the internal pressure of the capsule.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method and apparatus for industrially producing a high-density carbon material.

(Prior art) Carbon materials (excluding diamond) are divided into amorphous carbon and graphite, and each comes in various forms such as molded bodies and fibers, and their excellent heat resistance, stability against chemicals,
Due to its unique electrical properties, its field of application has expanded in recent years, from space materials such as rocket nozzles to artificial heart valves, and its field of application is expanding.

Particularly in recent years, with the development of high-strength, high-elastic carbon fibers that differ from conventional graphite and the like, their use as structural members has rapidly increased.

Only 1. Therefore, the parts used as functional materials for these weapons are generally required to have high density, and in particular, the development of 17II density, isotropic, and large-sized materials is urgently needed. There is. For example, increasing the density will dramatically improve the strength and corrosion resistance of the material, and is expected to expand its use in chemical equipment used under +gtt, biological materials, etc. Further, in the case of electrodes for electrical discharge machining, the demand for which has been increasing over the past few years, it has been recommended that the electrodes be isotropic because the electrical properties of the electrodes differ depending on the cutting direction, which affects the performance of the electrodes.

By the way, conventionally, these carbon materials are made by kneading a filler such as coke and a binder such as tar or pitch.
Because it is manufactured through a process of molding and then heating to carbonize the binder, it inevitably contains pores from which decomposed gas from the binder has escaped. Therefore, in order to reduce the amount of pores and increase the density, we impregnated it with tar pitch.
This carbonizing operation is repeated repeatedly.

However, in such a process, if the binder decomposition during firing is not carried out slowly, the product will crack, and the carbon yield is low, so the number of repetitions will be large, resulting in it taking several months to complete the product. The problem is derived.

In addition, in order to obtain isotropy, a method of molding fine coke particles using a cold isostatic pressing method (rubber press method) has been adopted, but the moldability is difficult unless 20% or more of the binder is mixed in. This made it difficult to reduce the porosity after the first firing.

In such a situation, as a method to solve each of the above problems, the molded body is housed in a can made of palladium, etc., which transmits only hydrogen among the gas components produced by decomposition, and from the outside of the can (isotropically A method of carbonizing while compressing the metal (see U.S. Pat. No. 3,249,964), and a method of immersing the compact in molten metal and firing it under fluid pressure (Japanese Patent Publication No. 1042/1982) ) have been proposed.

However, the former method has not been made into a second industry, partly because there is virtually no equipment that can carry out the method. However, regarding the latter, many issues remain to be considered, such as ensuring the reproducibility of product characteristics and removing solidified molten metal after firing and cooling.

On the other hand, in recent years, compressing gas by applying pressure at high temperatures has become popular.
The hydrostatic pressing II method (hereinafter abbreviated as the H'IP method) is becoming increasingly popular as a method for producing isotropic and high-density powder metallurgy products. According to this HIP method, for example, by sealing the powder raw material in an airtight container called a capsule and processing it, it is possible to produce a product with a high density in the above step. However, the processing temperature is about 2600°C, which is very effective, and considering that expensive and difficult-to-process high-melting point alloys such as Ta and W must be used as capsules, it is unlikely to be put to practical use.

However, the equipment used for this HIP method (hereinafter referred to as HIP
With the increase in demand in the powder metallurgy-related industries mentioned above, apparatuses with a processing chamber capacity of several hundred liters are now being manufactured, and are rapidly progressing. Therefore,
Based on the knowledge gained through the progress of these device technologies, various methods have been investigated to eliminate the drawbacks of the prior art (-1) and industrially produce high-density carbon materials.

(Objectives of the Invention) An object of the present invention is to provide an industrial method for manufacturing high-density carbon material products based on the knowledge of the IiP method, in light of the above-mentioned actual situation.

By the way, the present inventors have discovered that it is most suitable to use the crystal-sensitive high-pressure molding and sintering method previously proposed by the present applicant in JP-A-51-88503 when using the IP method. , tried to adopt it.

In this method, the object to be processed is enclosed in a capsule and inserted into a high-pressure container, and while the object to be processed is heated by a heating element built into the high-pressure container, the pressure medium in the high-pressure container is heated by isotropic ITE.
communicates with the inside of the capsule when pressurizing by contraction force,
This is a method in which an adjustment tube whose end extends outside the high-pressure container is provided, and the entire limb treatment body is heated and pressurized while adjusting the type of atmospheric gas and/or IE force inside the capsule through the adjustment tube. It is extremely useful to be able to perform heating and pressurizing treatment while adjusting the LLR force, but when trying to utilize this, it is necessary to use an adjustment tube to control the amount of pressure gas during treatment.
It was found that the +:i: was crushed and occluded by the E force and could not play a sufficient role of adjustment.

In particular, it is extremely important to increase the yield of carbon from tar pitch or other resins in order to obtain high-density carbon molded bodies. As shown in the relationship between carbon yield and pressure, the carbon yield tends to increase as the pressure increases, [1.: The influence of force has a large influence on the bond density carbon material. .

Therefore, there is still room for improvement in the high-temperature, high-pressure molding and sintering force method proposed by the present applicant, which was a major problem after -i.

(Fourteenth Object of the Invention) The present invention aims to achieve the above-mentioned improvement, and by filling the inside of the atmosphere adjustment tube with ceramic powder that is particularly difficult to sinter, the atmospheric pressure and the pressure inside the capsule can be well adjusted. The purpose is to achieve industrial production of high-density carbon material products.

(Structure of the Invention) That is, one of the features of the present invention that achieves the above object is that a molded body made of carbon and an organic material such as tar pinch is placed in an atmosphere "'Li:::1". The gas pressure outside the capsule is housed in a capsule made of hydrogen-permeable or hydrogen-absorbing metal and has a conditioning tube, and the inside of the atmosphere conditioning tube is filled with a ceramic powder that is difficult to sinter. The gas pressure inside the capsule is higher than the gas pressure inside the capsule, and the capsule is compressed from the outside with gas pressure and heated to raise the temperature.At the same time, the gas pressure inside the capsule is controlled through all the atmosphere adjustment tubes (in the method of firing one by one). .

Another feature of the present invention is a specific configuration of a high temperature and high pressure apparatus for carrying out the above method, in which a high pressure vessel defined by a high II cylinder and a lid below -L is provided. A heat insulating layer 1 A heating element is provided, and a capsule made of hydrogen-permeable or hydrogen-absorbing gold 1.14 gold is airtightly placed in the furnace chamber defined by the heating element with respect to the ambient gas in the furnace chamber. □T, and also provide an atmosphere adjustment tube 7X (connected to H) inside the capsule, the end of which extends outside the high-E container,
Another feature is that the interior of the adjustment tube is filled with ceramic powder that can be sintered.

Here, the sinterable ceramic powder to be filled inside the air conditioning tube includes oxides such as alumina, silica, zirconia, and magnesia, and nitrides such as silicon nitride and boron nitride. Carbides such as silicon carbide and boron carbide are included, and any of these may be used alone or in combination of two or more.

However, it is safe to circulate the gas, and the filling ratio is generally about 40 to 50%, but during processing [1:
It is important to ensure that the gas is not crushed or blocked by the pressure of the medium gas.

Note that the molded mixture of carbon and organic materials such as tar and pitch in the present invention decomposes when heated during the HIP treatment process and generates gas components such as hydrogen and hydrocarbons. If such substances are processed by the usual method of enclosing them in capsules, the above-mentioned gas components will increase the [T:] force inside the capsule, and the pressure of the inert atmosphere gas outside the capsule may not be able to sufficiently compress the substance, or the capsule may densification may not be possible because the particles will rupture.

Therefore, it is necessary to control the pressure f inside the capsule during the H-processing process, thereby making it possible to convert the above-mentioned molded article into a product with high densities. In particular, when the decomposition product gas is hydrogen, densification can be effectively achieved by utilizing the phenomenon that hydrogen gas diffuses through the capsule and is dissipated into the pressure medium gas outside the capsule.

The pressure inside the capsule can be controlled by drawing the gas inside the capsule out of the high-pressure vessel, converting this into a change in the IL power applied to the heating element, and adjusting the temperature inside the furnace, or by adjusting the temperature in the furnace, or by adjusting the temperature inside the furnace. It is also effective to discharge all the gas from the section, selectively measure its type and/or hk, and issue the results to the tuning pipe operation system or temperature and pressure adjustment system.

(Examples) Hereinafter, specific aspects of the manufacturing method of the present invention will be described in detail together with examples of the apparatus of the present invention.

FIG. 2 shows a cross-section of the main body of a high-temperature apparatus 11 suitable for carrying out the method of the present invention and the object to be treated disposed inside the main body.

In the figure, the Shimada container is divided into a high-pressure cylinder (1) and an upper lid (2) and a lower lid (3) that close the lower end of the cylinder, and each fitting part is made airtight by a sealing material (10) α6. The gas pressure acting on the lid is supported by a breath frame (not shown). Inside the high-pressure container are heating elements (4) (4) made of electrically heated resistance wires for heating and raising the temperature of the object to be processed (θ), and the heat from these heating elements is used to create a high-pressure cylinder (]) and an upper lid (2). .

A heat insulating layer (6) is incorporated which suppresses the dissipation of heat to the bottom 6 (3).

The object to be processed (13) is housed in a capsule (12) made of a material having hydrogen gas permeability or hydrogen gas storage property. An atmosphere adjustment tube 04) is attached to the capsule θ2). It is freely connected to the medium gas in the furnace chamber (7) through a seal ring 06) so as to maintain airtightness.

M tL JM Body (+3) is a molded body made of a mixture of carbon-based filler materials such as petroleum coke, anthracene coke, and carbon fiber, and organic material binders such as coal tar pitch and pheno-7'I/. . On the other hand, as the material for the capsule θ2), in addition to steel materials such as mild steel and stainless steel, platinum, palladium, etc. can of course be used. Further, the atmosphere adjusting pipe 0→ is usually made of the same material as the capsule (b) or made of steel because it can be easily connected to the joint α5). As explained as a feature of the present invention, the inside of this tube 0→ is filled with a hard-to-sinter ceramic powder (143) so that it will not be clogged by crushing due to the pressure of the pressure medium gas during processing. Although it is possible to add enough meat 1!A k Ij to the tube 0→ itself to withstand crushing, it is more preferable to use it in combination with the above-mentioned filling.Also,
The present invention also includes packing a porous ceramic sintered body instead of ceramic powder.

Note that a wire mesh filter is provided at the junction between the atmosphere adjustment tube (4) and the adjustment hole (11) to prevent the ceramic powder from becoming a low-temperature part and solidifying with the liquid.

Figures 3 and 4 show each joint between the capsule 02) and the atmosphere adjustment tube 0→ in the device, and the lids (12b) (12c) are welded to the top and bottom of the cylindrical capsule body (12a). In Fig. 3, a core θ2) made of a heat insulating material is interposed between the lower lid (12c) and the molded object α3), and the distance between the lid and the molded object is is placed.

On the other hand, in FIG. 4, the lower lid (12c) has an eave-like shape and is welded at a distance from the lid.

This was done in consideration of the effect it would have on the molded product since the temperature would be as high as 1500°C during welding.

Next, a procedure for increasing the density of a molded body using the above-mentioned apparatus will be explained, but the molded body can be manufactured by various methods. For example, petroleum coke powder is mixed with 20 to 30 parts by weight of coal tar pitch, kneaded at around 100°C, and molded using a mold.

In addition, when using carbon fa and not having much anisotropy, the purpose can be achieved by mixing an appropriate amount of a binder such as tar pitch and then performing cold or warm isostatic pressing. . It is also possible to heat a resin molded body and partially carbonize the resin molded body and use it as a molded body.

Then, such a molded body is housed in a capsule, and the following methods are suitable for manufacturing the capsule and storing the molded body in the capsule in the method of the present invention.

That is, after welding a thin-walled mild steel tube and a disk into a container shape and inserting the molded body into the container, the atmosphere adjustment tube 0→
In this method, a lid with an attached lid is joined to the container by welding. (See Figures 3 and 4) In this case, when welding the lid to the capsule body, the heat from welding may be transmitted to the molded body and cause the binder to decompose, so it is preferable to cool the container from the outside. , the distance between the lid and the molded body may be increased as shown in FIG. 3, and a heat insulating material may be filled in between, or a capsule shaped as shown in FIG. 4 may be used.

The object to be processed (molded object) accommodated in the capsule in this manner is then airtightly mounted 1a on a pedestal in the furnace chamber (7) as shown in FIG. In addition, the heating element holding cylinder (5
) If the heating element (4) held in (4) or the heat insulating layer (6) is made of molybdenum or graphite, which have poor oxidation resistance, the air that got into the furnace chamber (7) when the capsule was fixed is : Evacuate the inside of the high-pressure container through the vacuum hole (9) for discharge. After that, the pressure medium gas is supplied from the pressure medium gas introduction hole (8) at several to several tens of inches/crd as necessary.
It is introduced and discharged to replace and clean the gas inside the high-pressure container.

Next, the chamber is filled with pressure medium gas and the temperature is gradually increased. At this time, at the beginning of the temperature rise, that is, until the temperature reaches over 100°C, the inside of the capsule is vacuumed to remove moisture adsorbed on the inner surface of the capsule and the molded body. The binder starts to polymerize and carbonize when heated and heated to a temperature of 100 F-41, but in order to obtain a product with a high crystal density, after the start of polymerization, it must be compressed using the pressure of a pressure medium gas from the outside of the capsule. Then, the carbon-generating component in the binder component is finally decomposed into carbon and hydrogen, and the operation is performed so that as much carbon as possible remains in the voids of the compact, that is, to improve the carbon yield. It is preferable. From the latter point of view, several tens of Kf'ly/l of A are present in the capsule.
Good results can be obtained by raising the temperature in a state filled with r gas.

The pressure inside this capsule fluctuates depending on the pressure increase due to the expansion of Ar gas at 4 temperatures and the pressure of the gas component generated by decomposition of the binder. The pressure of the pressurized gas must be maintained higher than the pressure inside the capsule. In particular, from around 450℃, gases (mainly OH,
) must be careful not to cause the pressure inside the capsule to rise higher than the pressure of the pressurized gas and damage the capsule.

According to the present invention, it is possible to control not only the pressure of the pressurized gas but also the force inside the capsule, so that appropriate control is possible. From about 600°C, the copper phase, which is the capsule material, plays a catalytic role, and the decomposition of the binder progresses, and most of the generated gas components become hydrogen. In ry+J, the carbon in the binder contributes to the densification of the molded product! Do J. At this stage, it is preferable to control the pressure inside the capsule by controlling the rate of temperature rise from the standpoint of improving the carbon yield.

Regarding this point, Fig. 1 shows the relationship between the carbon yield of petroleum pitch and the [''H force].
It can be seen that the rate tends to increase with an increase of 1 toka, and this tendency is noticeable for about 501<g scale.

In this way, it is possible to produce a high-density carbon product by appropriately controlling the heating rate, the pressure inside the capsule, and the pressure of the pressure medium gas at each temperature stage.

FIG. 5 shows a piping system diagram for the tank that fully controls the pressure and atmosphere inside the capsule.

At the initial stage, the inside of the capsule is evacuated by closing the blocking valve (2 Enoki and blocking valve 1: 24 + 'ffi in the closed state).
Fully open the valve (23) and run the vacuum pump (2N) at full capacity.

Several 10K in the capsule? ,! The operation to introduce Ar gas is to close the blocking valve (221 and blocking valve (23), open the blocking valve (2d+) and blocking valve (2″O), and allow the argon gas in the furnace chamber to flow in, or Argon gas collection device 0'7)
This is done by injecting the water from the compressor 08) through the blocking valve (24). Of course, the blocking valve 04),
(23) A separate argon gas cylinder or a compressor may be connected to the circuit closed in (23).

Control of the relationship between the pressure inside the capsule and the pressure of the pressure medium in the furnace chamber, that is, the compression force of the object to be processed by the pressure medium gas, is controlled by the H-6 force meter ( 19) and the indicated value of the power supply (1) installed in the power system in the capsule. When the difference between the two becomes smaller than the expected value during the temperature rising process,
This can be achieved by increasing the pressure of the pressurized gas by driving the compressor (18) or by decreasing the gas pressure within the capsule by opening the blocking valve (22).

Which method to use for control can be selected depending on the stage of the processing process, as described above.

Processing 1. In order to improve the carbon yield after 11JJ in the middle of the process, is it more effective to control the heating rate described above? 1-: Easily achieved by controlling the input '+' and 1L forces to the heating elements (4) and (41) while observing changes in the indicated value of force (20). Ru.

In addition, in order to automatically control the input power, a heating power control device (30) is used, and the IF power Gt from the power meter (B) is connected to the main electric signal line and connected to the same equipment Takeuchi. It is sufficient to incorporate a control device that compares the desired pressure value with this force signal value and increases the input power if it is smaller than the desired pressure value, and decreases it in the opposite case. , the l] target can be achieved.

To further explain this in detail in the case of processing a molded body made of tar pitch and stone NI + coke, the pipe system and the inside of the capsule of the molded body are evacuated, and the inside of the furnace chamber is also vacuum pumped +2 [
Evacuate in step i). Next, close the dz valve (24)'ff
Fill the argon gas from the argon gas collecting device 07) with argon gas in the open state, and then open the opposite valve (24).
Close. At this time, the piping system leading into the capsule (a)
The internal pressure is set to be maintained at 300 W.

Argon gas is supplied only into the furnace chamber from the piping system (b), and at the same time, power is applied to the heating elements (4) (4').

At this time, when the molded body is heated, the tar pitch decomposes and decomposed gases such as 01 (, H□) are generated. Of these, I (2) permeates because the capsule is made of a hydrogen permeable material It dissipates into the argon gas inside the furnace chamber.

If the ratio of this dissipated gas and ht of the decomposition product gas is approximately equal, the pressure within the capsule, that is, within the piping system (a), will be a constant value.

Incidentally, the pressure in the piping system (a) rises due to gas generated by decomposition of tar pitch, but when it reaches 300 degrees, the temperature rate is controlled and maintained by the control function. Then, after a certain period of time has elapsed, the amount of tar pitch decomposed (11) decreases, and the temperature rises faster. As the time increases further, the decomposition ends and the V (power) in the piping system (a) begins to decrease. L
I'll leave it there. Therefore, the pressure inside the furnace was 1000"47 during this time.
If the molded body is held at
The differential pressure of E force, IffJ, is 700Kg, which results in two phases. [r:, If the force controller is set to 980Kg, the pressure inside the capsule will be 7
It is possible to prevent the capsule from expanding and bursting due to fi6 <.

Also, without using the heating power control device V as described above, commands can be selectively issued based on the type of generated gas and tIt to control the temperature.

It is also possible to control the pressure.

Figure 6 shows an example of this, and it is based on the fact that a change in the molecular weight of the generated gas due to heating of the object to be processed results in a pressure change inside the capsule.First, the gas serving as an indicator is selectively taken out. . Therefore, a safety valve (331) is connected to the suction device 0 via a solenoid valve from a part of the system of the atmosphere adjustment pipe O→.
When the sides are connected and the solenoid valve 64) is closed, the solenoid valve C31) is opened and the suction cap (321) is set to 11.
[Equipped with 4Iu of generated gas! i'7 Supply to C3 (g).

In addition, since there is a large difference in temperature between this extraction system and the temperature inside the high 1R container, condensation occurs within the system. Therefore, as a preventive measure, there are methods of keeping the yarn path warm or heating it, or installing a wrap to remove condensation, but the former is preferred.

In addition, regarding the adjustment pipes for collecting the generated gas, it is possible to install the necessary number of plural pipes as exhaust pipes and collection pipes for the gas generated from the object to be processed during heating, or to install it as a double pipe structure. Often, by installing and using multiple adjustment pipes in this way, it is possible to not only draw gas but also continuously supply atmospheric gas at any pressure during any operation, either independently or in parallel with HIP processing. I can do it.

In this way, when the measurement device (35) detects the generation of a gas serving as an index, the measurement device (35) switches to the other measurement device cxa, and this device performs the quantitative determination of the specific gas. The switching method uses the known principle that the index gas is absorbed by infrared rays at a specific wavelength position, and a detector is installed at a constant wavelength position.
operate.

Generally, the gases generated by the object to be processed are carbon and hydrogen.

Since it contains several types of components such as oxygen, it is appropriately selected from among the gases generated by evaporation and/or decomposition during heating, and is measured as the index gas in 1jiJ.

This measurement result is the temperature in the H-P equipment.

It has a function to issue commands to control pressure, and can adjust temperature and pressure.

The above is related control between the pressure inside the capsule and the atmospheric pressure during processing, but when the capsule is processed, the entire capsule is compressed from the outside.
The capsule is in a shrink fit state where the coefficient of thermal expansion is usually larger. In order to take out the molded body inside the capsule, the capsule is either chemically corroded and removed, or mechanically scraped off. However, the former method is problematic in that it takes a long time to remove and it is necessary to remove chemicals that have permeated into the molded body, so the latter method is usually used for removal. However, as mentioned above, the molded body is in a compressed state due to the shrink fit of the capsule, so when it is mechanically removed, the stress is suddenly released, causing a large rack in the molded body.

Figure 7 shows the configuration of a capsule that deals with the problem of
! Ceramic or carbon powder Gη with sinterability (used to maintain a porous shape at the processing temperature in the present invention) is applied to the inner surface of the capsule (12) and the molded body (I).
3) as a buffer material.

Therefore, when the stress is released, the stress is absorbed by the buffer material and the molded article is not damaged.

Note that ceramic powder that is difficult to sinter is free from H generated during processing.
2 permeates the capsule and dissipates to the outside, so the original effect is maintained as is. Furthermore, since ceramic powder adsorbs moisture and the like, it is preferable to evacuate the inside of the capsule before processing.

In the present invention, as described above, difficult-to-sinter ceramic powder is filled into an atmosphere adjusting tube, and fired while controlling the capsule Yamada force through the entire tube. The manufacturing method also includes the following.

That is, a r, which is known as the most common editing density method,
The raw material preformed by the P method is heated to room temperature and 2000 to 500
When densifying 0"q using a liquid pressure medium, no gas is generated because it is at room temperature, and therefore the volatile components are also trapped during the heating process, so this volatilization is removed during subsequent firing. The components decompose and scatter, creating pores.

In addition, a method known as the impregnation method involves adding pitch, phenol, furan, etc. to a pre-fired molded body and impregnating it.
This method involves curing in an autoclave, but even in this method, the only effect that can be expected is to reduce the evaporation of volatile components by the pressure of the autoclave, and the presence of pores is unavoidable. The same applies to cases where the carbon molded body is porous, for example, made of carbon fibers, and it is ultimately difficult to obtain the desired properties in terms of strength.

In such a case, it is preferable to introduce a carbonizing gas into the capsule at a pressure lower than the inert gas pressure outside the capsule, allow it to enter the voids formed in the compact, and deposit it as carbon by thermal decomposition.

At this time, the carbonizing gas can be introduced through the atmosphere adjustment tube, but it can also be introduced using another tube.

Fig. 8 is a piping system diagram for introducing carbonizing gas through the atmosphere adjustment pipe f:'M1, in which a carbonizing gas cylinder, a pressure reducing regulator G+, and a humbretsor OD+ are installed in the normal system. The carbonizing gas is fully pressurized into the capsule while maintaining the desired temperature, and when the amount of carbonizing gas injected becomes smaller than a predetermined value, the temperature is lowered and the internal pressure of the capsule is lowered at the same time.

Incidentally, when a carbonizing gas is introduced into the capsule, the introduced carbonizing gas is decomposed and finally decomposed into carbon as a solid and hydrogen as a gaseous body. Of these, carbon is accumulated in the pores in the molded body, while hydrogen as a gas diffuses into the capsule wall and dissipates into the Ar gas outside the capsule. Therefore, in order to create carbon of many lIk in the pores of the molded body, it is sufficient to supply carbonizing gas of many fi-t and to efficiently dissipate hydrogen produced by decomposition to the outside of the capsule.

To do this, it is effective to increase the pressure inside the capsule by increasing the absolute value of the carbonizing gas and thereby increasing the amount of hydrogen produced by decomposition.

FIG. 9 shows that the carbonizing gas inlet (river) is formed separately from the gas outlet (46) in the capsule, and the gas is exhausted from above the capsule (12) through the exhaust pipe (41).
Carbonizing gas is introduced from below.

In this case as well, the effect is the same, but 1a is preferred.

Below, the results of implementing the present invention in comparison with comparative examples will be shown.

(Comparative Example) ity &=+ 4'+ Instead n r+ -High 7: 30 parts by weight of coal tar pitch was added to 0 m ft+ part of ity &=+ 4'+ and after kneading at 140°C,
It was cooled to room temperature and ground. The obtained powder was placed in a rubber bag and molded using a rubber press at a pressure of 3000'&y. It was turned into a cylindrical shape and 1251 samples were obtained. and n were heated to 850° C. at a heating rate of 150% r under a nitrogen atmosphere of 1 atm, held for 2 hours, and then cooled down. The weight of the obtained fired body is 1olf, and the bulk density is 1
．． It was 38% 5;4. Moreover, numerous cracks were generated in the obtained fired body.

(Example) Cylindrical sample similar to the above comparative example (diameter 5Q 1f
fl x height 50 questions 1 weight 126.97) was housed in a mild steel capsule having the shape shown in Figure 3. This capsule was attached to a high-temperature field excavation device in the state shown in FIG. After evacuating the furnace chamber of the device and replacing it with argon gas, 12""
The furnace chamber was filled with 1 yll of argon gas, and the compact was compressed and carbonized by varying the temperature and the Yamada force in the furnace chamber as shown in FIG. At this time, the pressure inside the capsule is controlled mainly by operating the group 11 for releasing to atmospheric pressure, and the pressure within the capsule is 0 to 2.
It was adjusted so as not to exceed the range of 0""/cr/l. After lowering the temperature and pressure, the mild steel capsule was removed and the fired body was taken out. The dimensions and weight of the obtained sintered body were as follows:
Height: 45 mm, Weight: 10'7.4ff*o
m density u, ]-56'4r1 (and the occurrence of cracks was slight.

(Comparative Example) Next, a process similar to that in Example 1-1 was carried out using a high-temperature surface pressure device having the configuration shown in FIG. 2 and in which the adjusting tube was not filled with ceramic powder. As a result, the dimensions and weight of the obtained compact were 46 tan in diameter.

It had 47 fins and a weight of 1 jll and 15.8 s'f.

After the treatment, the same device was opened and compared with the previous example.
A collapse phenomenon was observed in a portion of the atmosphere adjustment tube, indicating that the pressure inside the capsule was not adequately controlled.

(Effects of the Invention) As described above, the present invention uses a capsule made of a hydrogen-permeable or hydrogen-absorbing metal having an atmosphere adjustment tube when firing a molded body made of carbon and organic forest materials such as tar pitch. Then, the molded body is stored in the capsule, and the inside of the atmosphere adjustment tube is filled with hard-to-sinter ceramic powder, and the capsule is heated while being compressed by pressure outside the capsule, and at the same time, the atmosphere adjustment tube is heated. By using the atmosphere adjustment tube filled with the hard-to-sinter ceramic powder, the atmosphere can be adjusted by the pressure during processing even when the pressure outside the capsule is high. The densification process can be carried out smoothly by ensuring appropriate control of the pressure inside the capsule without supernatant the supernatant, and the atmosphere and pressure around the molded product in the capsule can be controlled as described above. Significant effect 7: Through accurate adjustment, the yield of fixed carbon in organic forest materials can be improved and high-performance, high-density products can be obtained.
fr: play.

In addition, the method of the present invention combines increasing the gas pressure outside the capsule with respect to the gas pressure inside the capsule and controlling the pressure within the capsule accurately, thereby achieving a wide range from both product characteristics and economic efficiency. This makes it possible to control over a wide range of conditions, improve workability, and suppress the occurrence of cracks due to expansion of the molded product by sintering it while compressing it hydrostatically. This method is expected to be useful in the industrial production of low-density carbon materials.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the relationship between the carbon yield and pressure of petroleum pitch, Fig. 2 is a cross-sectional schematic diagram showing an example of the apparatus 1'J for carrying out the method of the present invention, and Figs. 3 and 4. 5 is a cross-sectional schematic diagram showing each of the tube-controlled capsules for atmosphere adjustment used in the present invention, FIG. 5 is a diagram of the IE force and atmosphere control piping system inside the capsule, and FIG. 6 is an outline of the HIP device showing another example of the control mechanism. figure,
Fig. 7 is a sectional view showing another embodiment of the capsule, Figs. 8 and 9 are a piping system diagram and a cross-sectional schematic diagram of the device of the present invention having a carbonizing gas introduction mechanism, and Fig. 10 is a cross-sectional diagram showing the present invention. This is a diagram of the inside of the furnace L (showing changes in force and temperature inside the furnace) when (1)...1~'(i-th:, cylinder, (2)...
...] Two lids. (3)...Lower lid, (4)(4)...Heating element. (6)...Heat insulation layer, (7)...Furnace chamber. (9)...Vacuum hole. (1))... Capsule internal atmosphere adjustment hole. (+2)... Capsule, (+3) Song...
Molded object (object to be processed). (l→・・・・・・Pipe for atmosphere adjustment. 0ゐ・・・・・・Difficult to sinter ceramic powder. Figure 1 Pressure (N44, Figure 2, Figure 3, Figure 4) Fig. f Fig. 9 4θ

Claims (1)

[Claims] 1. When completely firing a molded product made of carbon and an organic material such as tar pitch, the molded product is housed in a capsule made of a hydrogen-permeable or hydrogen-absorbing metal and has an atmosphere adjustment tube. Then, the inside of the atmosphere adjustment tube is filled with sinterable ceramic powder to allow gas flow, and at least the outside of the capsule is filled with gas pressure, and the temperature is increased by heating, and at the same time, the 1E force on the outside of the capsule is applied from the pressure inside the capsule. The capsule is fired while compressing the cell from the outside with a gas force (E force) and controlling the gas pressure inside the capsule through the atmosphere adjustment tube filled with the sulfur-binding ceramic powder. A method for producing a high-density carbon material. 2. The method for producing a high-density carbon material according to claim 1, wherein the inside of the capsule is characterized in advance at the beginning of temperature rise, that is, before the carbon-generating component in the tar pitch component starts to decompose. 8. A method for manufacturing the outside of the capsule inside the capsule when heating and raising the temperature. 4. The method for producing a high-density carbon material according to claim 8, wherein a carbonizing gas is introduced through an atmosphere adjustment tube. 5. The method for producing a high-density carbon material according to claim 8, wherein the carbonizing gas is introduced through a pipe that is separate from the atmosphere adjustment pipe. 6. The molded article according to any one of claims 1 to 5, wherein the molded article is housed with a hard-to-sinter ceramic or carbon powder interposed between it and the capsule when the entire molded article is housed in the capsule. Method for manufacturing density carbon material. 7. The method according to any one of claims 1 to 6, wherein the results of selectively measuring the type and/or amount of gas flowing in the atmosphere adjustment tube are used to control the gas pressure in the capsule. Method for manufacturing high-density carbon material. 8. Gas L1 in the capsule: ', - according to any one of claims 1 to 6, in which the force is controlled by adjusting the heating temperature by converting the gas extracted from the capsule. A method for manufacturing a 6-density carbon material. 9. The ceramic powder filled inside the atmosphere adjustment tube is selected from the group consisting of oxides such as alumina, silica, zilphnia, and magnesia, nitrides such as silicon nitride and boron nitride, and carbides such as silicon carbide and boron carbide. The method for producing a high-density carbon material according to any one of items 1 to 8, wherein the material is at least one type of powder. 10. Height 11: Height L1 defined by the cylinder and the 10F lid.Hydrogen permeation into the furnace chamber defined by the heating element by placing a heat insulating layer inside the container and all heating elements inside the container. A capsule made of a metal material capable of absorbing hydrogen or hydrogen is arranged airtight with respect to the ambient air gas in the furnace chamber, and an atmosphere adjustment pipe is provided, which communicates with the inside of the TFIJ capsule and whose end extends outside the high-pressure vessel. 1. A high-temperature, high-pressure device, characterized in that the atmosphere-adjusting tube is filled with a ceramic powder that is difficult to sinter. 11. The high temperature and high pressure device according to claim 10, wherein the capsule includes a core made of a heat insulating material between the molded body and the lower lid. 12. The high-temperature and high-pressure device θ according to claim 10, wherein the lower lid of the capsule is double-bottomed. 13. Patent Ni where the atmosphere adjustment tube is connected above the capsule! , the high temperature and high pressure device according to claim 10?
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