JPH02208214A - Production of molded carbonaceous body excellent in compression elasticity - Google Patents

Abstract

PURPOSE:To obtain a lightweight molded carbonaceous body excellent in elasticity by calcining or graphitizing a molded body of a mixture of elastic graphite particles with a binder. CONSTITUTION:Elastic graphite particles are mixed with a binder and the resultant mixture is molded and then subjected to calcining and/or graphitizing treatment to afford a molded carbonaceous body having <=1.0g/cm<3> bulk density and >=50% recovery ratio at 5-50% compression ratio. An elastic graphite substance prepared by treating carbonaceous mesophase produced by especially heat-treating pitches, such as petroleum-based or coal-based pitches, and/or raw coke with nitric acid or a mixed acid of the nitric acid and sulfuric acid, heat-treating and graphitizing the resultant product, etc., are preferably employed as the elastic graphite substance used. Pitches, such as coal tar pitch, bulk mesophase, thermosetting resin or thermoplastic resin is preferably used as the binder.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a carbonaceous material, and particularly to a method for manufacturing a carbon molded body made of carbonaceous or graphite material that is lightweight and has excellent elasticity.

[Background of the invention]

Generally, a carbonaceous molded body is manufactured by adding a binder to carbonaceous powder such as graphite or coke, kneading the mixture, shaping it, hardening it, and further firing and graphitizing it as necessary. The molding method and type of binder used at this time will depend on the purpose and use of the manufactured carbonaceous molded body.
Due to the different characteristics required, they are manufactured by many methods, and many research reports and proposals have been made for this purpose (for example, "Revised Introduction to Carbon Materials, p. 1135,
Carbon Materials Association; Mizutori and Okayama, ``Carbon Materials'', p. 55, Kyoritsu Shuppan; Ishikawa and Nagayu, ``New Carbon Engineering'', p. 173, Kindai Editorial Company).

These carbonaceous molded bodies have the characteristics of carbon, namely:
It has properties such as light weight, high strength, high modulus of elasticity, electrical conductivity, corrosion resistance, heat resistance, and sliding properties. However, although conventional materials are relatively advantageous when rigidity is required, especially in terms of high modulus of elasticity, they also have the disadvantage of lacking flexibility, and from a safety standpoint, they require even higher strength. The current situation is that these are in demand.

The present inventors had previously proposed an elastic graphite body with excellent elastic properties as a carbonaceous material (Patent Application No. 1648, 1982).
No. 08). This elastic graphite body is itself lightweight and exhibits good elasticity, and has excellent properties not found in conventional carbonaceous materials.

However, even if these carbonaceous materials themselves have good material properties, they are powder or granular materials, so they cannot be used alone and must be mixed with other materials. However, there were restrictions such as having to fill it in some kind of container before use.

Therefore, the present inventors discovered a method of binding elastic graphite particles to each other without impairing their elasticity by selecting the shape of the binder, and filed a patent application for the method for producing elastic graphite molded bodies. I did it. However, since the molded body uses resin, pitch, etc. as a binder,
Among the properties of carbonaceous materials, heat resistance, corrosion resistance, electrical conductivity, etc. are affected by the properties of the binder and are therefore inferior to those of carbon materials.

[Summary of the invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a novel carbon molded body made of carbon or graphite that is lightweight and has excellent compressive elasticity.

A feature of the present invention is a manufacturing method in which elastic graphite particles as a constituent material are shaped, fired, and/or graphitized without impairing their inherent elastic properties. That is, the method for producing a carbon molded body made of carbon or graphite according to the present invention involves mixing elastic graphite particles and a binder, shaping the mixture, and then
By firing and/or graphitizing the molded product, a lightweight and highly elastic product with a bulk density of 1.0 g/cut or less and a recovery rate of 50% or more at a compression ratio of 5 to 50% can be obtained. This method is characterized in that a carbon molded body made of carbonaceous or graphite is obtained.

[Detailed description of the invention]

As the elastic graphite body used as a raw material in the present invention, conventionally known ones can be used, but in particular, carbonaceous mesophase and/or raw coke produced by heat treating petroleum-based or coal-based pitches are used. , those obtained by treatment in nitric acid or a mixed acid of nitric acid and sulfuric acid, heat treatment, and graphitization, or those obtained by treating carbonaceous mesophase and/or raw coke with nitric acid or a mixed acid of nitric acid and sulfuric acid. After contacting with a basic aqueous solution to form a soluble component, an acid aqueous solution was added to precipitate the carbonaceous component, which was heat-treated.
A graphite body obtained by graphitization treatment may be preferably used.

The details of the method for producing graphite bodies having excellent elastic properties are described in, for example, Japanese Patent Application No. 164808/1982.

In the present invention, the elastic graphite particles as described above are used as raw materials, or the graphite particles have a diameter of 10 μm to 1 μm.
A thickness of about mm is preferable from the viewpoint of molding operability.

On the other hand, as the binder, pitches such as coal tar pitch, bulk mesophase, thermosetting resins, or thermoplastic resins can be preferably used. It is important that the binder be used in the form of a powder, sheet or film, or a dispersed resin prepared by dispersing a resin in a dispersion medium.

Conventionally, coal tar pitch, phenol resin, furan resin, and the like are known as binders used in the production of molded bodies of carbon materials and the like. These are 10
It is meltable at around 0°C, and in the molten state, it is kneaded with aggregate, then hardened, molded, fired, and/or graphitized to obtain a molded body.

However, the aforementioned elastic graphite particles have a spongy microstructure in which the internal partition walls are partitioned by thin carbon films, and this is the reason why they are lightweight and exhibit excellent compressive elasticity. It is thought that there is. Therefore, in molded bodies manufactured by conventional molding methods using binders, the molten binder enters inside the elastic graphite particles and impairs the elasticity of the elastic graphite particles.

As a result of further research focusing on the above drawbacks, the present inventor found that
By using a powdered binder as a binder, bonding occurs while the binder is in partial contact with the elastic graphite particles, so the binder penetrates into the sponge structure of the elastic graphite and impairs the structure and its elastic properties. It has been found that it is possible to obtain a good molded article without causing such a condition.

The powdery binder used in the present invention mainly includes pitches such as coal tar pitch, bulk mesophase, and thermosetting resins (e.g., phenolic resins, furan resins, epoxy resins, unsaturated polyester resins, polyimide resins, etc.)
Alternatively, thermoplastic resins (vinyl chloride resin, vinyl fluoride resin, acrylonitrile resin, etc.) are used. As the sheet-like binder, the above-mentioned thermosetting resin or thermoplastic resin sheets, films, etc. can be preferably used.

In addition, when using a dispersed binder, the type of resin etc. constituting the binder can be appropriately selected depending on the type of the intended molded product, but polyethylene,
Preferred are chain polymers that become fibrous, such as acrylic resins, epoxy resins, phenolic resins, and unsaturated polyester resins. Further, as the dispersion medium in this case, water, alcohol, inorganic acid, etc. are preferable. Also, in this case,
0.1 to 4.0 parts by weight of resin per 1 part by weight of dispersion medium,
Preferably 0. It is desirable to add 2 to 1.5 parts by weight.

In the present invention, the above-mentioned elastic graphite particles are used as an aggregate, and the above-mentioned binder is mixed therein.

In this case, the amount of resin is 0.00 parts by weight for 1 part by weight of elastic graphite particles. It is blended in an amount of 1 to 5 parts by weight, particularly preferably 0.5 to 5 parts by weight. If the amount of resin exceeds 5 parts by weight per 1 part by weight of elastic graphite particles, the bulk density of the resulting molded product tends to increase, which is not preferable.

When a powdered binder is used as the binder, the binder is added to the elastic graphite body, thoroughly mixed, and then placed in a desired mold and pressure-molded. In this case, it is preferable to crush the powder again and then perform the molding operation again in order to improve the properties of the molded product. Moreover, in this case, it is also possible to perform pressure molding under heating. The molded body may then be subjected to hardening of the binder and carbonization by heating, etc., and further subjected to firing and/or graphitization treatment.

When a sheet-like binder is used as the binder, elastic graphite particles are uniformly dispersed on a sheet cut to a certain size, and another sheet is stacked on top of this.

By repeating this operation, the elastic graphite body and the sheet are alternately laminated, and the molded body of the present invention can be manufactured through the same molding process as above. In addition, in this case, in order to improve the contact between the binder and the elastic graphite body, after applying a certain load to the above laminate, it is cured, and then subjected to firing and/or graphitization treatment. It is more preferable.

The above-mentioned firing and/or graphitization treatment of the molded product is
Usually 2000-3000°C, especially 2600-3000°
This can be done by heating to C.

Among the above-mentioned embodiments, it is preferable to use the above-mentioned dispersed binder as the binder in order to improve the elastic properties of the obtained molded article. Dispersed binder is a low-viscosity binder that is spherical and dispersed in a dispersion medium, so by mixing and kneading such a binder and elastic graphite particles that are aggregate, the binder is is stretched into a filament, and appears to be attached and entangled around the elastic graphite particles like a spider's web. Furthermore, in this case, the binder attached and entangled in a thread-like or spider web-like manner does not penetrate into the sponge structure of the graphite particles, but instead adheres to cover only the surface of the graphite particles and functions as a binder. Therefore, the elastic properties of the elastic graphite particles themselves as aggregates are not reduced.

When using the above-mentioned dispersion binder, an appropriate amount of water may be added during mixing so that the mixture becomes a good sticky consistency. This water may be added to the binder liquid in advance. In addition, if the amount of binder is too large and the mixture becomes muddy, it is possible to remove moisture as appropriate by drying the mixture after mixing.

In the present invention, except when a sheet-like binder is used as the binder, a mixing method that applies shear stress can be adopted when mixing the binder, and by adopting this shear wetting method, the above-mentioned Such a binder can further promote the development of a fine structure in which graphite particles are encapsulated. Such mixing can be done using static mixers,
This can be carried out using various devices such as a Henschel mixer, but it is also possible to use a pulverizer such as a ball mill or a pulverizer such as a Laikaiki.

The molded body thus obtained has properties that are lightweight and excellent in elasticity, which are not found in conventional carbonaceous molded bodies.

Hereinafter, the content of the present invention will be explained in more detail with reference to Examples.

Example 1 Raw coke obtained by a delayed coker method was finely pulverized to have an average particle size of 10 μm. This elemental composition is carbon 9
5.1 wt%, hydrogen 3.1 wt%, and nitrogen 0.6 wt%. 5 g of this was added little by little to 100 ml of a mixed acid of 96% concentrated sulfuric acid and 70% concentrated nitric acid in a volume ratio of 50:50 in a 300 ml Erlenmeyer flask. After adding the entire amount,
The mixture was heated for 4 hours in an oil bath preheated to 80°C. Then, filter it with a glass filter (No. 4),
After thoroughly washing with water, it was dried. The yield was 140% by weight.

This was dispersed in water, and 2.5N-NaOH was added while stirring until the pH reached 10. Then, it was filtered through a glass filter (No. 4), and the filtrate was diluted with lNHNO3 to pH
(hereinafter, the precipitate is referred to as aqua mesoface). Aqua Mesoface was filtered through a glass filter (No. 4) and dried. At this time, the yield of aqua mesophase was 133% by weight based on the raw coke. This Aqua Mesoface was placed in a 500 ml cylindrical glass container, placed in a salt bath preheated to 300°C, and held for 30 minutes. Then, in an argon stream,
It was heated to 2800°C at a temperature increase rate of 400°C/hr and held for 30 minutes to perform graphitization treatment. The yield based on raw coke was 85.52% by weight, respectively.

Compressive elasticity (compressibility, recovery rate) of the graphitized sample (elastic graphite body) was measured as follows.

Put 0.5g of the sample crushed to 0.30++++n or less into a cylindrical container with an inner diameter of 10mm, and add 1kg from the top.
A load of /c- was applied. The sample volume at this time is the standard (h
o). Then, a predetermined load was applied and the volume was measured. This volume was defined as hl. Next, the load was removed, and the compressibility and recovery rate were determined from these values using the following equations, with the volume at that time being h2.

Compression rate (%) = ((ho-h,)/ho) x 100 Recovery rate (%) - ((h - h )/ (ho-h,)
)x100 Also, the packing density was determined from ho.

Packing density Cg/cI) - Sample weight.

The results are shown in Table 1.

Example 1 0, 23 Example 2 0.18 Example 3 0.35 This elastic graphite body was crushed to 0.15 m+n or less, and phenol resin (Nireshito Tsubu PG3518 manufactured by Gunei Chemical Co., Ltd.
) After uniformly mixing the powder with the composition shown in Table 2, it was filled into a mold with a diameter of 13 mm and molded at a pressure of 2 Ton/c-. In order to improve the properties of the molded product, it was ground again and the molding operation was repeated four times. The obtained molded body was heated for 18 hours (held for 3 hours) to cure the J-nor resin, and then heated for 80 hours at an lr temperature rate of 60°C/hr.
The heating rate was increased to 3° and held for 1 hour to carbonize.Furthermore, the heating rate was 400°C/hr i'7' 28 OL
The mixture was heated to 1° C. and maintained for 30 minutes to graphitize to obtain molded product 7.

These compression properties are shown in Table 32. Table 2 No. Phenolic resin (wL%) Elasticity A
Lead body (, Wi%) 1 75
2') Table No., Dimensions (mm) Bulk density diameter x height (g/cc) 1 9.6 4.0 0.81 2 10.6 4.7 0.68 Load Compressibility (kg/cJl ( %) Example 2 2 kg of FCC decant oil, from which low-boiling components with a boiling point of about 500°C or less were removed in advance by vacuum distillation, was placed in a 5-liter container, heated to 500°C with stirring in a nitrogen gas stream, and heated for 2 hours. After holding, heating and stirring were stopped, and the mixture was allowed to cool.

When the internal temperature reached 400℃, after a total of 3 hours had elapsed after starting cooling while maintaining this temperature by heating,
Approximately 1.6 kg of pitch-like material was taken out from the extraction hole provided at the bottom of the container. Add about 3 quinolines to this pitch-like material.
Add twice the amount, heat to about 300℃, and add quinoline under reflux for 30 minutes.
Time processed. Next, insoluble components were separated using a centrifuge, fresh quinoline was added to the insoluble components, heated to 90° C., and then centrifuged. Insoluble components were thoroughly washed with benzene and acetone and dried. The obtained melon with insoluble components is]
When the structure was observed using a polarizing microscope, it was found that the entire surface had an anisotropic outer phase with a flow structure. Therefore, this insoluble component was used as a carbonaceous mesophase.

]5 The elemental composition of the carbonaceous mesofugose thus prepared was 93.4% carbon, 3.6% hydrogen, and 0.5% nitrogen. and ], 5 g of particle size of 17-0.70 ml]l
In a 300 ml Erlenmeyer flask, add 100 ml of a mixed acid of 96% concentrated sulfuric acid and 70% concentrated nitric acid at a ratio of 50:50 hλ.
1 was added little by little. After adding the entire amount, add 5
It was heated for 60 minutes in an oil bath heated to 0°C. Then, it was filtered through a glass filter (No. 4), thoroughly washed with water, and then dried. The yield was 38.6% by weight. This was placed in a 500 ml cylindrical glass container, placed in a salt bath preheated to 300°C, and held for 30 minutes. The yield is 95% based on the raw carbonaceous mesophase.
It was 9% by weight.

Then, in an argon stream, the temperature was increased at a heating rate of 400°C/min for 2 hours.
It was heated to 800°C and held for 30 minutes to perform graphitization treatment. The yield was 65.0% by weight based on the carbonaceous mesophase.

Regarding this elastic graphite body, the packing density and compressive elasticity (compressibility, recovery rate) were measured in the same manner as in Example 1. The results are shown in Table].

This elastic graphite body was crushed to 0.10 mm or less, and Example 1
After molding in the same manner as above, sintering and graphitization (7) A molded body was obtained. The blending ratio of the phenolic resin powder and the elastic graphite body at that time is shown in Table 4. The compression characteristics of these molded bodies were It is shown in Table 5.

No.

Table 4 Phenolic resin (vt%) Elastic graphite (wt%) Table No. Dimensions (mm) Bulk density diameter x height (g/cc) 3 C2, 13, 50, 97 412, 92, 90, 94 Load Compressibility (kg/cJ) (%) Example 3 100 ml of a mixed acid with a 50:50 volume ratio of 96% concentrated sulfuric acid and 70% concentrated nitric acid is placed in a 300 ml Erlenmeyer flask and cooled in a water bath in advance. To this, 5 g of raw coke, which was the same as that used in Example 1, was crushed and adjusted in the order of 0.15 to 0.30, and was added little by little. After adding the entire amount, it was held for 1 hour. Then, 500m cooled with ice
Pour into the water from No. 1 and use a glass filter (No. 4).
), washed thoroughly with water, and dried. The yield is 1
It was 54.0% by weight. This was heat treated and graphitized in the same manner as shown in Example 1. The yields based on raw coke were 89.5 and 57.6% by weight, respectively. Table 1 shows the measurement results of the compressive elasticity (compressibility, recovery rate) of the obtained elastic graphite body.

After uniformly mixing the elastic graphite body crushed to 0.30 mm or less with the same phenol resin used in Example 1 and the composition shown in Table 6, it was filled into a mold heated to 100°C and heated at a pressure of 50 kg/cJ. After pressurizing for 5 minutes and cooling, it was taken out. The obtained molded body was heated to 1000° C. at a temperature increase rate of 30° C./hr and held for 1 hour to carbonize, thereby obtaining a molded body. The compression characteristics are shown in Table 7.

Comparative Example 1 The same raw coke used in Example 3 was used at 0.15 to 0.
．． The powder was crushed and adjusted to 30 mm, heated to 1000 °C at a temperature increase rate of 200 °C/hr, held for 1 hour and calcined, then heated to 2800 °C at a temperature increase rate of 400 °C/hr, and heated to 2800 °C at a temperature increase rate of 30 It was held for a minute and graphitized. The yield at this time was 90.1% by weight based on the raw material raw coke.

This was pulverized to 0.30 mm or less, which was then molded and carbonized in the same manner as described in Example 3 to obtain a molded body. Table 7 shows the compression properties of this molded body.

Comparative Example 2 The same elastic graphite used in Example 2 with a particle diameter of 0.30 or less was treated with phenol resin (manufactured by Hitachi Chemical Co., Ltd.: VP80).
P) and the weight ratio of elastic graphite body:resin-(40:
60,50:50), then filled into a mold and heated under a pressure of 80kg/c+If.
It was cured at 180°C for 30 minutes.

Furthermore, after post-curing the phenol resin by holding at 180°C for 3 hours, it was heated to 800°C at a temperature increase rate of 60°C/hr and held for 1 hour to carbonize.

Furthermore, it was heated to 2800°C at a temperature increase rate of 400°C/hr and held for 30 minutes to graphitize to obtain a molded body. Table 7 shows the compression properties of this molded body.

Table 7 Dimensions (related) Bulk density Load Compressibility Recovery rate Diameter x height (g/ee) (kg/crl) (%)
(%) Example 3 liB 5.8 0.49
15 18 51 Comparative Example 1 13.4 5
．． 2 1.13 50 1.2 67 Comparative Example 2 ■9.7 4.0 ■9.9 4.8 0.86 0.64 2.6 1.0 Table 6 Phenolic resin (vt%) Elastic graphite ( νt%) Example 3 40 60 Comparative Example 1 40 60 Comparative Example 2
■ 40 60■ 50
50

Claims (2)

[Claims] 1. After mixing elastic graphite particles and a binder and molding, the molded product is fired and/or graphitized to give a bulk density of 1.0 g/cm^3 or less,
A method for producing a carbon molded body, which is characterized by obtaining a lightweight and highly elastic carbon molded body having a recovery rate of 50% or more at a compression ratio of 5 to 50%. 2. Composed of an elastic graphite body and carbonaceous or graphitic carbon, with a bulk density of 1.0 g/cm^3 or less and a compressibility of 5 to 5
A lightweight and highly elastic carbon molded body having a recovery rate of 50% or more at 0%.