JP2002160969A - Method for manufacturing glassy carbon porous material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a high quality glassy carbon porous material easily and economically. SOLUTION: The method for manufacturing the glassy carbon porous material comprises the steps of (A) crushing waste parts manufactured from a glassy carbon by means of a crusher, (B) screening the crushed powders obtained in the step A into a particle size of less than 800 μm by means of a sieve or a sieving machine, (C) mixing the crushed and screened powders obtained in the step B with a heat curing resin and a solvent and then kneading, (D) preforming the kneaded resin obtained in the step C by charging into a forming vessel of a desired shape, (E) obtaining a porous heat cured matter of the desired shape by heat curing the kneaded resin charged into the forming vessel in the step D until a releasable hardness, and (F) firing the porous heat cured member obtained in the step E at a temperature of 800 deg.C or higher and in an inert gas atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a glassy carbon porous material, and more particularly, to a method for easily and economically producing a glassy carbon porous material from a used component made of glassy carbon. On how you can do it.

[0002]

2. Description of the Related Art Conventionally, various methods for producing a porous carbon material including glassy carbon have been known. For example, a method using a phenol resin or a cured furan resin,
Examples include a method of firing a resin foam such as melamine, urethane, and phenol, and a method of manufacturing from a C / C composite material precursor. Among these, particularly, a method for producing a glassy carbon porous body includes impregnating a carbon fiber or urethane foam (foam) with a thermosetting resin, drying, and firing at a high temperature in an inert gas atmosphere. Or a method of obtaining a porous body by kneading and molding a micro-spherical thermosetting resin with the same kind of liquid thermosetting resin, drying, and then firing at a high temperature in an inert gas atmosphere to obtain a porous body. It has been known. JP-A-6-32677 discloses a method of carbonizing a resin foam such as a melamine resin foam or a urethane resin foam impregnated with a polycarbodiimide resin to obtain a porous carbon material.

[0003] However, when producing a glassy carbon porous material, a method using carbon fiber or urethane foam involves the following.
Because impurities are contained in carbon fiber or urethane foam as a base material, there is a problem that it cannot be used for applications requiring high purity, such as water purifier filter applications, In such a case, the carbon fiber itself is expensive, and as a result, there is a problem that the porous product becomes expensive.In addition, in the method using a thermosetting resin having a small spherical shape, like the carbon fiber, There are problems that the production cost of the micro-sphere thermosetting resin is high and the porous product becomes expensive.

[0004] Therefore, in the method of producing a glassy carbon porous body by the conventional method, there are problems such as the above-mentioned quality and economy. There has been a strong demand for a method for producing a glassy carbon porous body that can obtain the above.

On the other hand, used products such as plasma generators and electrodes for CVD devices whose material is glassy carbon are:
Since it is currently discarded without being reused, there is also a cost for disposal, and its effective use has been strongly desired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional method for producing a porous glassy carbon material and to obtain a high-quality porous glassy carbon material easily and economically. To provide a method for producing a porous glassy carbon material.

[0007]

Means for Solving the Problems In view of the above problems, the present inventor has conducted intensive studies on a method of manufacturing a glassy carbon porous body. Used materials such as electrodes as raw materials for porous materials, and crushing, sieving, kneading with thermosetting resin and solvent, preforming, molding, and performing specific processing over multiple steps from firing, high quality It has been found that a glassy carbon porous material can be obtained easily and economically. The present invention has been completed based on these findings.

That is, according to the first aspect of the present invention,
(A) a step of pulverizing a used part made of glassy carbon with a pulverizer, (B) a pulverized powder obtained in the step A,
800μm particle size by sieve net or sieving machine
(C) a step of kneading the pulverized and sieved product obtained in step B, a thermosetting resin and a solvent, and (D) a kneaded resin obtained in step C. And (E) a step of thermosetting the kneaded resin in the molding container of step D to a releasable hardness to obtain a porous thermosetting product having a desired shape; and (F)
B. Sintering the porous thermoset obtained in step E in an inert gas atmosphere at a temperature of 800 ° C. or higher. .

Further, according to the second aspect of the present invention, the first aspect
In the invention, a particle size of the pulverized and sieved product obtained in the step B is less than 500 μm, and a method for producing a glassy carbon porous material is provided.

Furthermore, according to a third aspect of the present invention, in the first or second aspect, the thermosetting resin kneaded in the step C is a phenol resin or a furan resin. A method for producing a porous carbon material is provided.

Further, according to the fourth invention of the present invention, in any one of the first to third inventions, the amount of the thermosetting resin kneaded in the step C is 100 parts by weight of the pulverized and sieved product. Thus, a method for producing a glassy carbon porous material, which is 30 to 200 parts by weight, is provided.

On the other hand, according to the fifth aspect of the present invention, the first
The present invention provides a glassy carbon porous body obtained by any one of the fourth to fourth inventions.

As described above, the present invention relates to a high-quality, easy and economical method for producing a glassy carbon porous body using a used part made of glassy carbon. Includes the following:

(1) A method for producing a porous glassy carbon material according to the first or second aspect of the present invention, wherein the particle size of the pulverized product obtained in the step B is less than 200 μm. (2) In the fourth invention of the present invention, the kneading ratio of the pulverized and sieved product and the thermosetting resin is the same as that of the pulverized and sieved product 1
A method for producing a glassy carbon porous body, wherein 40 to 150 parts by weight of a thermosetting resin is added to 00 parts by weight. (3) In the first aspect of the present invention, the firing temperature is 100
A method for producing a glassy carbon porous material, which is performed at 0 to 3000 ° C.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The method for producing a glassy carbon porous body of the present invention comprises:
As shown in FIG. 1, the method comprises the following six steps. (A) Pulverizing step: a step of pulverizing a used part made of glassy carbon with a pulverizer (B) Sieving step: The pulverized powder obtained in step A is sieved with a sieve net or a sieving machine to a particle size of less than 800 μm. (C) Kneading step: a step of kneading the pulverized sieving product obtained in step B, a thermosetting resin and a solvent (D) Preforming step: kneading the kneaded resin obtained in step C (E) Molding (thermosetting) step: The kneaded resin in the molding container of step D is thermoset to a releasable hardness, and porous thermosetting of a desired shape (F) Firing step: The porous thermoset obtained in step E is
Firing at a temperature of 800 ° C. or more in an inert gas atmosphere

1. Pulverizing Step (A) In the method for producing a glassy carbon porous body of the present invention, first, a step of pulverizing a used part made of glassy carbon with a pulverizer, that is, a pulverizing step is employed. The used glass-carbon used parts used as the raw material of the glass-like carbon porous body include electrodes and susceptors for plasma generators and CVD apparatuses whose material is glass-like carbon, and used members such as other members. A high-purity grade used product such as a semiconductor application is preferable.

The vitreous carbon of the used part is also referred to as non-graphitizable carbon or hard carbon, and any raw material and production method may be used as long as it is produced by solid phase carbonization of an organic substance. May be used and is not particularly limited. Examples of the raw material of the glassy carbon include a thermosetting resin such as a phenol resin, a furan resin, and a polycarbodiimide resin, a thermoplastic resin, and the like. Proposed. In addition, a glassy carbon simple substance is preferable, but in addition to the glassy carbon simple substance, a resin cured powder, carbon fiber, or the like may be mixed to improve properties.

As the pulverizer, a used part made of glassy carbon is used to reduce the particle size to less than 800 μm, preferably 50 μm.
There is no particular limitation as long as it can be crushed to less than 0 μm, but an intermediate crusher or a fine crusher is preferable. Examples of such a pulverizer include a dodge crusher, a ball mill, a tube mill, a rod mill, a cutter mill, a rotary cutter and the like.

2. Sieving step (B) Next, the glassy carbon pulverized powder obtained in the previous step (A) is sieved with a sieve mesh or a sieving machine to a particle size of 8%.
The step of sieving to less than 00 μm, that is, the sieving step is performed. In the present invention, the sieving operation is performed to remove large flour. If the particle diameter of the pulverized powder made of glassy carbon is 800 μm or more, the shape cannot be maintained when the porous body is produced by firing, and therefore, it is not used in the present invention. Therefore, the particle size of the pulverized powder is 800
It is sieved to less than μm, preferably less than 500 μm, more preferably less than 200 μm, and the sieved product having the particle size is used in the present invention.

As a sieve net or a sieving machine, any one capable of sifting the ground powder of a used part made of glassy carbon to a particle size of less than 800 μm, preferably less than 500 μm, and more preferably less than 200 μm, There is no particular limitation.

3. Kneading Step (C) Next, a step of kneading the pulverized and sieved product obtained in the previous step (B), a thermosetting resin and a solvent, that is, a kneading step is performed. In the porous glassy carbon material obtained in the present invention, the thermosetting resin functions as a binder, and the composition (type and amount) of the pulverized product made of glassy carbon and the thermosetting (binder) resin By adjusting such factors, a high-performance porous body having high mechanical strength and a certain shape can be obtained.

As the thermosetting resin, a phenol resin,
Examples thereof include an epoxy resin, a furan resin, a melamine resin, and an unsaturated polyester resin, and a phenol resin or a furan resin used as a raw material of glassy carbon is preferable. Further, a compound having a function of a thermosetting resin by blending a curing agent with a thermoplastic resin can also be used.
Novolak-type phenol resin mixed with hexamethylenetetramine as a curing agent can also be used.

As a solvent, a pulverized product made of glassy carbon and a thermosetting (binder) resin are kneaded well,
There is no particular limitation as long as it volatilizes and disappears in the subsequent molding step and firing step, and examples thereof include methanol, ethanol, tetrahydrofuran, dioxane, and dimethylacetamide.

The kneader is not particularly limited as long as it can uniformly disperse a pulverized product made of glassy carbon, a thermosetting (binder) resin, and a solvent. Examples of such a kneader include a mixing roll, a Banbury mixer, an internal mixer, and a twin-screw continuous mixer. Also, pulverized products made of glassy carbon,
A mixer may be used as long as it can uniformly disperse the thermosetting (binder) resin and the solvent. Examples of the mixer include a ball mill, a pebble mill, a ribbon mixer, and a super mixer.

The mixing ratio of the pulverized product made of glassy carbon and the thermosetting resin at the time of kneading is 30 to 200 parts by weight of the thermosetting resin, preferably 100 parts by weight of the pulverized product made of glassy carbon. It is 40 to 150 parts by weight. As for the mixing ratio of the solvent, an amount for properly kneading the pulverized product made of glassy carbon and the thermosetting resin is appropriately selected and mixed.

4. Preforming step (D) Next, a step of putting the kneaded resin obtained in the preceding step C into a forming container having a desired shape and performing preforming, that is, a preforming step is performed. In the present invention, a molded container having a desired shape, for example, a circular or square shape, is used depending on the use of the obtained glassy carbon porous body. The molding container is not particularly limited, but is preferably a heat-resistant container in consideration of the following steps. A molded container made of plastic, for example, polypropylene, a molded container made of metal, for example, stainless steel, or a mold used for compression molding may be used. In this step, the molding conditions are not particularly specified, and the fluidization may be performed by applying heat and pressure, and the molding may be performed into a predetermined shape using a mold or a molding container.

5. Molding (thermosetting) step (E) Subsequently, the kneaded resin in the molding container of the preceding step (D) is
A step of thermosetting to a releasable hardness to obtain a porous thermosetting product of a desired shape, that is, a molding (thermosetting) step is performed. The molding (thermal curing) conditions are not particularly limited as long as the kneaded resin is thermally cured to a hardness that can be released from the molding container. The maximum temperature for thermosetting is 150-2.
00 ° C. Usually, if it is a molded container made of plastic, it is thermoset at a temperature of, for example, 70 to 90 ° C. for 1 to 2 days to obtain a porous thermosetting product.

6. Firing Step (F) Next, a step of firing the porous thermoset obtained in the preceding step (E) at a temperature of 800 ° C. or more in an inert gas atmosphere, that is, a firing step is performed. As the inert gas, usually, nitrogen or argon gas is used, and it is fired in a non-oxidizing atmosphere. Also, change to an inert gas atmosphere,
It may be fired in a vacuum. 800 ° C as firing temperature
The above temperature is required, preferably 1000-3000 ° C
It is. The heating rate at this time is not particularly limited, but is not more than 10 ° C./min, especially 5
C./min or less is desirable. Thus, the thermoplastic resin used as the binder resin is mainly baked, and as a result,
Only the carbon of the thermoplastic resin remains (others disappear) to become glassy carbon, and a uniform glassy carbon porous body can be obtained together with the raw glassy carbon sieved product.

Method for producing the porous glassy carbon material of the present invention
The glassy carbon porous body obtained by the method is 800
Since it is fired at a temperature of ℃ or higher, high quality
It has excellent mechanical strength. The resulting glassy mosquito
The physical properties of the porous carbon material include various production conditions, for example,
Depends on the raw materials and the mixing ratio of the thermosetting resin, etc.
If the bulk density is 600-800kg / m³Porosity is 2
0-50%, compressive strength 100-300kg / cm ²so
is there. Used glass-like carbon used materials are originally
Low cost for producing porous material because it is waste
It's economical. Also, the glassy car that is no longer needed
The disposal cost of used Bonn-made electrodes can be reduced.
You. Further, the method for producing the glassy carbon porous body of the present invention
As mentioned above, the method itself has no complicated processes and is easy
One is economical.

Since the glassy carbon porous material obtained by the production method of the present invention has high purity and high strength, it can be used as a filter, a filter, an adsorbent (agent), a catalyst, an electrode substrate for a fuel cell or a capacitor. And the like.

[0031]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not particularly limited to these examples.

Example 1 A used product of a 6-inch plasma-etched electrode made of glassy carbon and a phenol resin (PL-4804 manufactured by Gunei Chemical Industry Co., Ltd.) as a thermosetting resin as a binder were used in the following procedure. To produce a glassy carbon porous body. Table 1 shows evaluations of physical properties such as bulk density, compressive strength, and porosity of the produced glassy carbon porous body. The obtained porous body had sufficiently high compressive strength as a filter for a fluid subjected to pressure. still,
Compressive strength was measured and evaluated according to JIS R7212, and dust detachment was visually evaluated. Step A (pulverizing step): A used product of a glassy carbon plasma etching electrode is pulverized using a cutter mill. Step B (sieving step): From the pulverized powder obtained in step A, only a pulverized powder of less than 200 μm is taken out using a 200 μm mesh. Step C (kneading step): 100 g of the pulverized and sieved product having a size of less than 200 μm obtained in step B, and thermosetting resin 100
g, and 100 ml of methanol as a solvent are kneaded. Step D (preliminary molding step): The kneaded resin of step C is placed in a circular molded container made of polypropylene. Step E (molding / thermosetting step): The kneaded resin put in the molding container is thermoset sequentially at 70 ° C. for 20 hours, at 80 ° C. for 10 hours, and at 85 ° C. for 10 hours to have a diameter of 100 mm and a thickness of 15 mm. To obtain a porous cured product of Step F (firing step): The porous cured product is heated to 1200 ° C. in an inert gas (nitrogen) atmosphere at a rate of 1 ° C./min.
The temperature was raised to 0 ° C., followed by firing, followed by cooling to obtain a glassy carbon porous body.

Example 2 In step B of Example 1,
Using a mesh of 50 μm and 200 μm, except for taking out only pulverized powder of 50 μm or more and less than 200 μm,
In the same manner as in Example 1, a glassy carbon porous body was produced. Table 1 shows evaluations of physical properties such as bulk density, compressive strength, and porosity of the produced glassy carbon porous body. The obtained porous body had sufficiently high compressive strength as a filter for a fluid subjected to pressure.

Comparative Example 1 Graphite powder was bonded with glassy carbon in the same manner as in Example 1 except that spherical graphite having an average particle diameter of 50 μm was used as the pulverized powder in Steps A and B of Example 1. A porous body was prepared. Table 1 shows the evaluation of physical properties such as bulk density, compressive strength, and porosity of the porous body.
The obtained porous body had insufficient compressive strength as a filter for a fluid under pressure.

[Comparative Example 2] In step B of Example 1,
A porous cured product was obtained in the same manner as in Example 1 except that only the pulverized powder having a particle size of 50 μm or more and less than 1 mm was taken out as the pulverized powder. However, when this cured product was fired in the same manner as in Example 1, the pulverized powder was not adhered to each other, and the shape as a porous body could not be maintained.

[0036]

[Table 1]

As is evident from Table 1, the glassy carbon porous bodies obtained in Examples 1 and 2 have a good evaluation of dust desorption, and have a compressive strength of 200 kg / cm ² , whereas the comparative examples have a compressive strength of 200 kg / cm ^2. When spheroidal graphite was used as a raw material in Example 1, dust desorption was large and the compressive strength was 70 kg / cm ² , which was poor. In addition, in the case of Comparative Example 2 in which the raw material glassy carbon has a particle diameter of more than 800 μm,
As described above, the shape as a porous body could not be maintained even after firing.

[0038]

According to the method for producing a porous glassy carbon material of the present invention, since a used product made of glassy carbon, which is originally a waste, is used as a raw material, low cost production of the porous material is achieved. Furthermore, there is no complicated process, and it is easy and economical. Further, the glassy carbon porous body obtained by the present production method is high in purity and excellent in mechanical strength.

[Brief description of the drawings]

FIG. 1 is a view showing a manufacturing process of a glassy carbon porous body.

Claims (5)

[Claims] (A) a step of pulverizing a used part made of glassy carbon with a pulverizer; (B) a step of pulverizing the pulverized powder obtained in step A with a sieve net or a screening machine to a particle size of less than 800 μm (C) kneading the pulverized and sieved product obtained in step B, a thermosetting resin and a solvent, and (D) mixing the kneaded resin obtained in step C in a molding container having a desired shape. The step of putting and preforming,
(E) a step of thermosetting the kneaded resin in the molding container of Step D to a releasable hardness to obtain a porous thermosetting product having a desired shape; and (F) a step of forming the porous heat obtained in Step E. Cured product,
Baking at a temperature of 800 ° C. or more in an inert gas atmosphere. 2. The crushed and sieved product obtained in step B has a particle size of less than 500 μm.
The method for producing a glassy carbon porous body according to the above. 3. The method for producing a glassy carbon porous body according to claim 1, wherein the thermosetting resin kneaded in step C is a phenol resin or a furan resin. 4. The amount of the thermosetting resin kneaded in the step C is 30 to 2 with respect to 100 parts by weight of the pulverized and sieved product.
The method for producing a glassy carbon porous body according to any one of claims 1 to 3, wherein the amount is 00 parts by weight. 5. A vitreous carbon porous material obtained by the method for producing a vitreous carbon porous material according to claim 1.