JPH06305852A - Production of hollow molded article of active carbon - Google Patents

Abstract

PURPOSE:To readily obtain a hollow molded article of active carbon having excellent handleability, containing a functional heatresistant material in the interior without requiring a complicated production process. CONSTITUTION:A particulate substance of a thermoplastic resin such as polyethylene containing a functional heat-resistant material such as zeolite or silver on the surface or in the interior is arranged in active carbon powder, the thermoplastic resin is heat-treated for melting.carbonization, e.g. in the case of polyethylene, the polyethylene is infusibilized in an oxidizing atmosphere at relatively low temperature and then carbonized in a nonoxidizing atmosphere to give a hollow molded article of active carbon containing the heat-resistant material in the interior.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hollow activated carbon molded product.

[0002]

2. Description of the Related Art Various methods for producing hollow bodies are known depending on the materials used. Among them, heat resistance,
As a method for producing a carbon-based hollow body, which is expected to be used as a lightweight material having excellent performance such as chemical resistance,
After uniformly mixing a thermoplastic organic polymer material, a bituminous raw material such as petroleum pitch with an expanding agent such as a low boiling point solvent, a powder having an appropriate particle size is formed, and then carbonized by heating to form a hollow carbon body. Method of obtaining (for example, Japanese Examined Patent Publication Sho 49-30253
Japanese Patent Publication No. 61-14110, Japanese Patent Laid-Open No. 61-110
No. 83239), or a method of coating a core material such as a thermoplastic resin with a substance having a high melting point to form a multi-layered sphere, and then heating and carbonizing it (see, for example, Japanese Patent Publication No. 50-29837). ing.

Among the methods for producing a carbon-based hollow body, the method of using an expanding agent is as follows: selection of an expanding agent suitable for each raw material, handling of organic solvents, adjusting method of expanding agent-containing particles, and further, There is a problem in that it is difficult to set conditions and handle during the heat treatment, and there is a drawback in that a hollow body having a relatively large particle size can be obtained by a method having a multilayer structure.

Therefore, the Applicant does not require a complicated manufacturing process such as using a swelling agent or a multi-layer structure, and produces hollow activated carbon moldings having various particle diameters by a very simple process. One of the proposals was previously made regarding the manufacturing method (Japanese Patent Application No. 4-102097). Using a particulate thermoplastic resin and activated carbon powder, after arranging the particulate thermoplastic resin in the activated carbon powder, by melting and carbonizing the particulate thermoplastic resin to produce a hollow activated carbon molded article It is a thing. Here, the hollow molded article is not a mere aggregated particle of activated carbon powder, but the activated carbon powder does not enter the molten particulate thermoplastic resin, but the molten particulate thermoplastic resin is activated carbon. It is presumed that this is because the powder (aggregate) permeates into the gaps between the powders (aggregates).

The present invention further develops the above-mentioned proposal, and by utilizing the hollow shape of the obtained activated carbon molded product to contain an appropriate heat-resistant material inside, the function of this heat-resistant material is also exhibited. It is something to try.

[0006]

According to the present invention, a particulate thermoplastic resin and activated carbon powder are used. After the particulate thermoplastic resin is placed in the activated carbon powder, the particulate thermoplastic resin is melted and carbonized. In producing a hollow activated carbon molded product by carrying out the above, a method for producing a hollow activated carbon molded product is characterized in that the particulate thermoplastic resin contains a heat resistant material in advance.

The details will be described below. As the particulate thermoplastic resin used in the present invention, for example, polyethylene, polypropylene, polystyrene, nylon, polyvinyl chloride,
Examples include various materials such as polyvinyl acetate. A carbon yield of about 1 to 10% by heat treatment is preferable. Here, the carbon yield also changes depending on the method of heat treatment. For polyethylene, polypropylene, polystyrene, nylon, etc., the carbon yield is 1 by subjecting to infusibilizing treatment in an oxidizing atmosphere and then carbonizing treatment in a non-oxidizing atmosphere. ~ 1
It will be about 0%. Further, it is preferable to heat-treat polyvinyl chloride, polyvinyl acetate, etc. in a non-oxidizing atmosphere without performing infusibilizing treatment in an oxidizing atmosphere. The particle size of the particulate thermoplastic resin depends on the degree of carbon yield,
If it is too large, it becomes difficult to maintain the shape of the obtained hollow activated carbon molded product. Of course, it is all right if it is about several mm. Further, it is preferably 5 times or more the particle size of the activated carbon powder. In addition, polyethylene is several μm to 1000 μm
There are various spherical and granular products with various particle sizes that exceed the range as commercial products, not only is it easy to set the size of the hollow activated carbon molded product to be obtained, but also the shape of the obtained product is almost Will be equal.

As the heat-resistant material to be contained in the particulate thermoplastic resin, any heat-resistant material that can withstand the heat treatment until a hollow activated carbon molded product is obtained and has a heat resistance sufficient to be present in the hollow activated carbon molded product is appropriately used. it can. To give an example, gold, silver,
Copper, titanium oxide, etc. can be used, or zeolite can be used for the purpose of exerting an ion exchange function and a drying function. Activated carbon may be included. For example, if it contains activated carbon having a different property from the activated carbon constituting the hollow activated carbon molded product (the activated carbon that is bonded by the particulate thermoplastic resin as described above, the skin-forming activated carbon), it has different adsorption functions inside and outside. Will be things. In the case of a device having a plurality of functions, which function is to be exerted is appropriate.

To incorporate the heat-resistant material into the particulate thermoplastic resin, for example, a granulator is used to coat the thermoplastic resin powder around the core with the heat-resistant material as the core, or the heat-resistant material and the thermoplastic resin are mixed. A dispersion mixture with resin powder is obtained, and this is made into a particulate substance, and if necessary, the outer surface thereof is further coated with a thermoplastic resin powder, or a heat-resistant material is mechanochemically embedded in the particulate thermoplastic resin. You can do it. The use ratio of the heat resistant material and the thermoplastic resin is also appropriate.

As the activated carbon powder, regardless of the raw materials and the manufacturing method, etc., the properties and the particle size may be appropriately selected in consideration of the intended use of the hollow activated carbon molded product to be obtained and the particle size of the particulate thermoplastic resin. Good. Further, it is also appropriate in terms of a shape such as a completely amorphous shape or a fibrous shape.
Chemically activated carbon may have a higher content of impurities than gas-activated carbon, and if this amount of impurities is too high, it may hinder the formation of hollow activated carbon moldings. If the impurities are removed by washing with the above inorganic acid, a hollow activated carbon molded article can be obtained better.
The particulate thermoplastic resin is placed in this activated carbon powder, but if the activated carbon powder is present in a thickness greater than the wall thickness of the hollow activated carbon molded product to be obtained around the particulate thermoplastic resin. Good.

As described above, the heat treatment is carried out by inducing infusibility by raising the temperature from room temperature to 250 to 350 ° C. in an oxidizing atmosphere such as air or oxygen depending on the kind of the particulate thermoplastic resin, and then in the particulate form. Up to the temperature at which the thermoplastic resin carbonizes,
The firing treatment is performed in a non-oxidizing atmosphere such as an inert gas such as nitrogen or argon or in a vacuum, or the firing treatment is performed directly in a non-oxidizing atmosphere without performing the infusibilizing treatment in an oxidizing atmosphere. Here, when the above-mentioned one is used as the particulate thermoplastic resin, the baking treatment may be performed at about several hundreds of degrees Celsius. You may perform an activation process as needed. After the heat treatment, excess activated carbon powder is removed with a sieve or the like to obtain a hollow activated carbon molded product. The function of the heat resistant material may be exerted in a state where the hollow activated carbon molded product is crushed or the like, if necessary.

As described above, the mechanism by which the hollow activated carbon molded product is formed is not necessarily clear, but the particulate thermoplastic resin placed in the activated carbon powder is once melted by heat treatment and becomes fluid, This penetrates into the interstices between the activated carbon powders (aggregates), in other words, the activated carbon powder particles are stuck one after another, and then the particulate thermoplastic resin remains as a carbide to serve as a binder, and thus the hollow activated carbon It is considered that a molded product is formed.

The obtained hollow activated carbon molded product can be used as it is, but if the hollow portion has a margin other than that occupied by the heat-resistant material, the performance is improved or another function is added by further filling with another substance. Can be achieved. For example, when pesticides, insecticides, etc. are filled, they are once adsorbed by the activated carbon on the outside and then gradually released, so that they can be sustained-release pesticides or sustained-release insecticides that can maintain a long-term effect. Further, a combination with a material used as a heat resistant material may be considered, for example, if iron powder or the like is used as a heat resistant material, magnetized and filled with a drug, a sustained release effect of the drug by activated carbon, Since it has the effect on the living body by the magnetic force, it can be used for medical purposes. As a method of filling the hollow portion with another substance, a general method such as immersing the hollow activated carbon molded product in a solution containing the substance to be filled can be used.

[0014]

【Example】

<Example 1> 5 parts by weight of MFP-3100 (silver powder manufactured by Mitsui Kinzoku Kogyo KK; average particle size: 1 [mu] m) was used as flow beads C.
20 parts by weight of L-2507 (a true spherical polyethylene manufactured by Sumitomo Seika Chemicals Co., Ltd .; a particle size range of 100 to 250 μm) was treated with a hybridization system (manufactured by Nara Machinery Co., Ltd.) at 6000 rpm for 5 minutes to obtain silver powder. To obtain polyethylene particulate matter (excessive silver powder was removed), which was placed in Kuraray Coal PK100 (powdered activated carbon manufactured by Kuraray Chemical Co., Ltd .: particle size; 100 mesh or less) and placed in air. From room temperature to 300 ° C 1
The infusibilizing treatment is carried out by raising the temperature at a rate of about ℃ / minute and holding at 300 ℃ for 1 hour, and then 600 ° C in a nitrogen atmosphere.
A calcination treatment was performed at 1 ° C. for 1 hour (excess activated carbon powder was removed) to obtain a hollow activated carbon molded product containing silver powder.

Example 2 Powdered activated carbon fiber (Kuraray Chemical Co., Ltd .; average fiber diameter 10 μm, average fiber length 5)
0 μm) 10 parts by weight and SNP-6643 (Nylon powder manufactured by Metal Color Co., Ltd .; average particle size 43 μm) 50 parts by weight are uniformly dispersed and mixed in a mixer, and granulated by a tumbling granulator. Except that the surface was coated with SNP-6643 (described above) to obtain a particulate matter having a diameter of about 500 μm as a whole, which was used instead of the particulate matter used in Example 1.
The same procedure as in Example 1 was carried out to obtain a hollow activated carbon molded product containing powdered activated carbon fibers.

<Example 3> Polyethylene powder (Powdered polyethylene manufactured by Mitsui Petrochemical Co., Ltd .; particle size range: 10 to 50 μm) around spherical zeolite (Sumitomo Chemical Co., Ltd .; particle size: 500 to 1000 μm) Was coated (using a tumbling granulator) to obtain a polyethylene-containing particulate material of zeolite, which was placed in diasorb F200 (powdered activated carbon manufactured by Mitsubishi Kasei Co., Ltd .: particle size: 200 mesh or less). Then, the same heat treatment as in Example 1 was performed to obtain a hollow activated carbon molded product containing zeolite.

[0017]

INDUSTRIAL APPLICABILITY According to the present invention, hollow activated carbon moldings having various particle diameters, and those containing a functional heat-resistant material inside, can be easily prepared without requiring a complicated manufacturing process. Obtainable.

Claims (1)

[Claims] 1. Hollow activated carbon molding using a particulate thermoplastic resin and activated carbon powder, arranging the particulate thermoplastic resin in the activated carbon powder, and then melting and carbonizing the particulate thermoplastic resin. A method for producing a hollow activated carbon molded article, characterized in that a heat-resistant material is previously contained in the particulate thermoplastic resin in producing the article.