JPH0114166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing carbon products having a dense and dense structure. More specifically, the present invention relates to a method for producing a carbon product having a dense and sparse structure in which sparsely structured carbon molded bodies and densely structured carbon molded bodies alternately form a structure.

In this specification, the term carbon includes carbonaceous and graphitic substances, a loose structure is a structure made of carbon porous material, and a dense structure is a structure made of carbon porous material, and a dense structure is a structure made by adding a binder and filler as necessary. This refers to the structure of a carbon material obtained by firing it in an inert gas atmosphere after being subjected to a carbon precursor treatment, and the structure such as fine cracks in the binder part that inevitably occurs during the firing process is not called a porous structure. . In addition, after mixing and kneading the compounded composition to obtain a dense structure, it can be shaped into an arbitrary shape using a molding machine or the like, or the surface of the organic polymer particles can be melted and point-bonded to obtain a loose structure. The state in which the particles are bonded together is called the green state. Furthermore, the carbon precursor state refers to a method in which a green compact is treated by adding a carbonization accelerating catalyst, a crosslinking agent, or a polymerization initiator, by acid treatment, or in an atmosphere of Cl ₂ , O ₃ , air, etc.
It is in a state in which it has been rendered insoluble or infusible by means such as heating crosslinking at 50 to 300°C or crosslinking and curing by irradiating with ultraviolet rays, electron beams, or other radiation.

Carbon products have excellent oxidation resistance and chemical resistance, and exhibit excellent heat resistance and corrosion resistance without melting and deforming in non-oxidizing atmospheres. Porous bodies made of carbon with such excellent properties can be used as various filters for solid separation in liquids, catalyst carriers, activated carbon or adsorbents after chemical activation treatment, lightweight structures, heat insulation materials, etc. It can be used for battery electrodes, sheet heating elements, etc. In addition, dense structure carbon compacts can be used in heat exchangers, distillers, evaporators, absorbers, concentrators, etc.
It is used in overheating equipment, etc.

However, to date, a carbon molded body in which a loose structure carbon and a dense structure carbon made of a porous body are integrated has not been obtained. If this is achieved, it is expected that it will be used in a wider range of fields.

Therefore, the object of the present invention is to provide a method for manufacturing a continuous heterogeneous carbon body having a designed sparse and dense structure by integrally manufacturing a carbon porous body having high strength and a uniform pore distribution and a dense structure carbon molded body. It is to provide.

In order to achieve this objective, the inventors of the present application have conducted extensive research and have developed a green-state molded product of a compounded composition that basically produces dense carbon by firing in an inert gas atmosphere, or a carbon precursor thereof. The molded body in the oxidized state, or the composite formed by integrally molding the calcined carbide and chlorinated vinyl chloride resin particles using a liquid composition, is treated to become a carbon precursor if necessary, and then calcined in an inert gas atmosphere. proposed a method for producing carbon products with a dense and dense structure (patent application 1983).
−138347). However, this method can only produce a relatively thin carbon part with a relatively thin structure, cracks are likely to occur in the carbon part with a loose structure and a carbon part with a dense structure during carbon precursor treatment and during firing, and the joining of both structural parts is difficult. It had drawbacks such as weak

Therefore, as a result of further intensive research, the inventors of the present application have discovered that one or more types of organic polymer substances, asphalt pitches, and carbonized pitches, which can yield dense structure carbon by firing in an inert gas atmosphere, have been developed. A molded body made of a mixture or a blend with fine graphite powder if necessary, and a surface layer of organic polymer particles that are sintered into granules to obtain loose structure carbon by firing in an inert gas atmosphere are melted. After solidification, the organic polymer porous material with point adhesion between particles is formed into an inert composite using an organic liquid composition that leaves a high carbon residue and is fired in an inert gas atmosphere. We have succeeded in eliminating the above-mentioned drawbacks by devising a method for manufacturing carbon products having a dense and dense structure, which involves firing in a gas atmosphere. Note that the addition of graphite powder contributes to improving molding stability.

The method for producing a carbon product having a dense and dense structure according to the present invention will be specifically explained below.

First, a green-state molded body that becomes dense structure carbon is formed by firing in an inert gas atmosphere. This is done by uniformly mixing a mixture of one or more organic polymer substances, asphalt pitches, carbonized pitches, etc., and fine graphite powder using a mixer such as a Henschel mixer, and then This mixture is processed using a pressure kneader, two rolls, three rolls,
The kneaded material is kneaded under heat using a kneader that can apply a high shear force such as a co-kneader, and the kneaded product is shaped into a plate using a calender roll, an extrusion molding machine, an injection molding machine, etc.
It can be obtained by molding it into any shape such as a rod. By subjecting this green-state molded body to a carbon precursor treatment, a molded body in a carbon precursor state is obtained. The organic polymer substances used include thermoplastic resins such as polyvinyl chloride, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride-vinyl acetate copolymers, phenolic resins, furan resins, epoxy resins, and unsaturated polyesters. Natural polymer substances such as curable resins, lignin, and cellulose,
It includes synthetic polymer substances having a condensed polycyclic aromatic group in the basic structure of the molecule, such as a formalin condensate of naphthalene sulfonic acid. Examples of asphalt and pitch include petroleum asphalt, coal tar pitch, naphtha cracked pitch, etc., and carbonized products of hydrocarbon compounds such as synthetic resins at temperatures below 400°C. Moreover, graphite is graphite with an average particle size of 0.5 to 15 μm. Next, a molded body in a green state from which this dense structure carbon is obtained,
In order to combine either of the molded bodies in a carbon precursor state with a porous body in a green state and a carbon precursor state, from which loosely structured carbon can be obtained, at the stage of carbonization,
An organic liquid composition consisting of a mixture of one or more of organic polymeric substances asphalt pitches and carbonized pitches and fine graphite powder is applied. Organic polymer substances here include thermoplastic resins such as polyvinyl chloride and polyacrylonitrile,
Thermosetting resins such as phenolic resins and furan resins,
It is a natural polymeric substance such as gum tragacanth. In addition, asphalt pits are petroleum asphalt,
Coal tar pitch, etc., and graphite is the average particle size.
It is graphite with a thickness of 0.5 to 15 μm.

The organic polymer material, pitch, graphite, etc. to be used is preferably the same as that used for forming the dense structure portion, since this leads to an increase in bonding strength. If the resin does not exhibit a liquid state at room temperature, use an initial condensate of the resin or a resin dissolved in a solvent. At this time, by adding about 5 to 50 parts by weight of graphite, the bond can be made stronger during carbonization.

Next, the sparse structure portion and the dense structure portion are bonded using an organic liquid composition as a bonding agent. For example, when creating a laminated product with a dense and dense structure with a square bottom,
A green-state molded body in which an organic liquid composition is coated on an organic polymer porous body in a green state or a carbon precursor state with a square-bottom surface to obtain a dense-structured carbon with a square-bottom surface. Place any of the carbon precursor molded bodies and repeat this operation until the desired number of layers is reached. In addition, when creating a product with a dense structure on the inside and a sparse structure on the outside, prepare a porous organic polymer with holes of the desired shape inside, and apply an organic liquid composition into the holes to create a dense structure. Operations such as inserting a columnar shaped body in a green state or a carbon precursor state from which carbon can be obtained are performed.

Thereafter, the organic liquid composition is solidified by heating, solvent removal, etc., thereby joining the sparse structure portion and the dense structure portion. After the shape adjustment operation as described above, carbonization is carried out by heating and raising the temperature to 800°C or higher, preferably 1000°C or higher in an inert gas atmosphere, with or without performing carbon precursor treatment as necessary. . In this way, a carbon product having a sparse structure in which a sparse structure part and a dense structure part are joined is obtained. At this time,
There is no upper limit to the firing temperature, and it may be heated up to about 3000°C if necessary. Porous bodies made of organic polymer particles have continuous pores because the particles sinter together to form a network structure and carbonize in that form without completely melting the resin during the heating process. A strong carbon porous body having the following characteristics can be obtained. To obtain good adhesion between the sparsely structured part and the densely structured part, the heating rate is 3 to 100°C/hr up to 500°C, preferably 5 to 50°C.
It is appropriate to fire at ℃/hr. There is no particular restriction on the rate of temperature increase from 500°C or higher. The carbon porous body obtained by this operation exhibits high strength. In order to increase the pore diameter of the carbon porous material, a material with a large particle diameter may be used, and in order to reduce the pore diameter, a material with a small particle diameter may be used.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Furan resin initial condensate [Hitafuran VF-302 manufactured by Hitachi Chemical Co., Ltd.] 50 parts by weight and chlorine content 67% polymerization degree
740 chlorinated vinyl chloride resin powder [Nicatemp T-870 manufactured by Nippon Carbide Co., Ltd.] 30 parts by weight Average particle size 7μ
20 parts by weight of graphite powder (CSP manufactured by Nippon Graphite Co., Ltd.) was uniformly mixed using a Henschel mixer. Next, the mixture was thoroughly kneaded using two heated rolls. After kneading, mold it using a calendar roll.
A plate with a thickness of 1.5 mm was obtained. The obtained plate-shaped body was placed in a heating oven and subjected to carbon precursor treatment at 150°C for 4 hours and then at 180°C for 8 hours to obtain a carbon precursor. Process this board into a square of 50 mm long x 50 mm wide,
An organic liquid composition consisting of 70 parts by weight of a furan initial condensate and 30 parts by weight of graphite powder was applied to one side of the film. Next, the chlorinated vinyl chloride resin powder was put into a graphite box using a vibrator, and placed in an oven heated at 180℃ for 20 minutes.
A porous body of chlorinated vinyl chloride with a thickness of 20 mm was prepared by holding it for a certain period of time, and this porous body was processed into a size of 50 mm in length and 50 mm in width. Thereafter, this porous body and a plate coated with an organic liquid composition were joined together, and the liquid part was solidified at 80°C in an air bath. Then, from room temperature under nitrogen gas atmosphere.
10℃/H up to 300℃, 30℃/H from 300℃ to 500℃,
Firing was performed at a temperature increase rate of 200°C/H from 500°C to 1000°C, and after cooling, a carbon molded body having a dense and dense structure was obtained.

The obtained molded body had a length of 41 mm, a width of 41 mm, and a height of 16 mm.

Example 2 The two-roll kneaded product of Example 1 was pelletized using a pelletizer, and a rod-shaped body with a diameter of 2 mm was obtained using a screw extruder. This was placed in a heating oven and subjected to carbon precursor treatment at 180°C for 10 hours, then cut into a length of 50 mm and coated with Example 1 on the entire side surface.
An organic liquid composition was applied. Next, from the chlorinated vinyl chloride porous material of Example 1,
A pipe-shaped porous body with a hole of 2 mmφ in diameter was fabricated. A rod-shaped body coated with an organic liquid composition is placed in this porous body, and after bonding, it is placed in an air bath.
The liquid part was solidified at 80°C. This is heated under a nitrogen gas atmosphere at 10°C/H from room temperature to 300°C, and from 300°C to 500°C.
C. was 20.degree. C./H, and firing was performed at a heating rate of 100.degree. C./H from 500.degree. C. to 1000.degree. C., and after cooling, a carbon molded body having a dense and dense structure was obtained.

The obtained molded body had a diameter of 15.5 mmφ and a length of 39 mm.

Example 3 80 parts by weight of chlorinated vinyl chloride resin particles [T-025 manufactured by Nippon Carbide Co., Ltd.], 20 parts by weight of graphite powder with an average particle size of 7 μm [Nippon Graphite CSP Co., Ltd.], and 15 parts by weight of dioctyl phthalate as a plasticizer. Parts by weight were added and thoroughly mixed using a Henschel mixer. Next, the mixture was thoroughly kneaded using two rolls. After kneading, the mixture was pelletized using a pelletizer and extruded using a plunger-type hydraulic forming machine to a cross-sectional shape of 30 mm long x 5 mm wide to obtain a plate-shaped body. This plate was cut into a length of 50 mm to obtain a green molded product. Three sheets of this were prepared, and an organic liquid composition consisting of chlorinated vinyl chloride resin, graphite, and tetrahydrofuran was applied to the front side of the first sheet, both sides of the second sheet, and the back side of the third sheet.

Next, a curing agent was added to a furan initial condensate (Hitafuran VF302, manufactured by Hitachi Chemical Co., Ltd.) and crosslinked using three heated rolls to obtain a sheet-like composition having a softening point of 150°C, which was cooled and crushed. This was placed in a graphite box using a vibrator and kept in a heating oven at 150°C for 10 hours to obtain a furan resin porous body. From this porous body, length 30mm x width 50mm x thickness 10mm
Two perforated plates were prepared. This porous plate was sandwiched and bonded to a plate coated with an organic liquid composition, and the liquid portion was solidified at 70°C in an air bath. After that, under nitrogen gas atmosphere, from room temperature to 300℃, 10℃/H,
20℃/H for 300 to 500℃, 20℃/H for 500℃ to 1500℃
Firing was performed at a temperature increase rate of 50° C./H, and after cooling, a carbon multilayer body having a dense and dense structure was obtained.

The obtained molded body is 23.5mm long x 41mm wide x 29mm high.
It was warm in mm.

Claims (1)

[Scope of Claims] 1. A mixture of one or more of organic polymer substances, asphalt pitches, and dry distilled pitches, and fine-grained graphite powder, from which dense-structured carbon can be obtained by firing in an inert gas atmosphere. A molded body made of a compound and a surface layer of organic polymer particles, which are sintered into particles to obtain loose structure carbon by firing in an inert gas atmosphere, are melted to create point adhesion between the particles. After assimilation, a porous organic polymer consisting of the following materials is integrally shaped using an organic liquid composition that leaves a high carbon residue by firing in an inert gas atmosphere, and the composite is fired in an inert gas atmosphere. A method for producing a carbon product having a dense structure consisting of: 2. The manufacturing method of item 1, wherein the molded body is in a green state or a carbon precursor state. 3. The manufacturing method according to item 1, wherein the organic polymer particles have a diameter or maximum side of 1 mm or less, and 90% or more of the particles have a diameter or maximum side of 30 μm or more. 4 Organic polymer particles include particles of thermoplastic resins such as chlorinated vinyl chloride, polyacrylonitrile, polyvinyl alcohol, polyphenylene ether, and polydivinylbenzene, thermosetting resins such as furan resins, phenolic resins, and bismaleimide/triazine resins. Particles obtained by curing resin monomers or initial condensates to the extent that they can be thermally deformed or soluble in solvents, and condensed polycyclic aromatics such as gum tragacanth, gum arabic, and sugars within the basic structure of the molecule. Natural polymer particles with a fused polycyclic aromatic group in the basic structure of the molecule, synthetic polymer particles not included in the above, petroleum asphalt, coal tar pitch, synthetic resin, etc.
The manufacturing method according to item 1, which is a mixture of one or more types of particles obtained by heat-treating at 500°C and removing low-molecular compounds with a solvent and then pulverizing them. 5. The manufacturing method according to item 1, wherein the organic liquid composition is one or a mixture of two or more of organic polymer substances, asphalt pitches, and dry distilled pitches. 6. The organic liquid composition is a first composition in which fine graphite powder is blended with a mixture of one or more of organic polymer substances, asphalt pitches, and dry distilled pitches.
Manufacturing method of section. 7. The manufacturing method of Paragraph 1, in which firing is performed by heating to a temperature of 800°C or higher.