JP3175288B2 - Method for producing hollow activated carbon molded product - Google Patents

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 an activated carbon molded article used for, for example, a filter or a catalyst carrier, which is required to have excellent activated carbon function and good handling properties.

[0002]

2. Description of the Related Art Various methods are known for producing hollow bodies depending on the materials used. Among them, the production method of carbon-based hollow body, which is expected to be used as a lightweight material having excellent performance such as heat resistance and chemical resistance, includes thermoplastic organic polymer materials and bituminous materials such as petroleum pitch. After uniformly mixing a swelling agent such as a low-boiling solvent with the mixture, a powder having an appropriate particle diameter is obtained, and then carbonized by heating to obtain a carbon hollow body (for example, Japanese Patent Publication No. 49-30253, Japanese Patent Publication No. No. 61-14110, JP-A-61-83239
And 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 carbonizing by heating (for example, see Japanese Patent Publication No. 50-29837). I have.

[0003]

Among the methods for producing a carbon-based hollow body, a method using an expanding agent involves selecting an expanding agent suitable for each raw material, handling organic solvents, and preparing particles containing an expanding agent. There is a problem that it is difficult to adjust conditions, furthermore, it is difficult to set conditions and handle at the time of heat treatment, and there is a drawback that only a hollow body having a relatively large particle diameter can be obtained by a method having a multilayer structure.

[0004] Therefore, the present invention uses a swelling agent,
It does not require complicated manufacturing processes such as passing through a multilayer structure,
An object of the present invention is to provide a method for producing hollow activated carbon molded products having various particle diameters by a very simple process.

[0005]

The present invention SUMMARY OF], after using the particulate thermoplastic resin and activated carbon powder, and the said particulate thermoplastic resin is disposed in the activated carbon powder, at least the surface of the particulate thermoplastic resin A method for producing a hollow activated carbon molded article containing a large amount of carbide on the inside and a large amount of activated carbon powder on the outside, characterized by once carbonizing after melting.

The details will be described below. As the particulate thermoplastic resin used in the present invention, for example, polyethylene, polypropylene, polystyrene, nylon, polyvinyl chloride,
Various materials such as polyvinyl acetate are exemplified. Those having a carbon yield by heat treatment of about 1 to 10% are preferred. Here, the carbon yield varies depending on the method of heat treatment. For example, polyethylene, polypropylene, polystyrene, nylon, and the like are infusibilized in an oxidizing atmosphere and then carbonized in a non-oxidizing atmosphere to obtain a carbon yield of 1%. ~ 1
It is about 0%. Further, it is preferable that polyvinyl chloride, polyvinyl acetate, and the like be subjected to a heat treatment in a non-oxidizing atmosphere without performing the 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, if it is about several mm, it is OK. Further, it is preferably at least 5 times the particle size of the activated carbon powder. In addition, polyethylene is several micrometers-1000 micrometers.
Spherical and granular materials of various particle sizes exceeding the market are available as commercial products, and not only the size of the hollow activated carbon molded product to be obtained is easy to set, but also the shape of the obtained product is almost Become equal.

[0007] Activated carbon powder can be appropriately selected in properties and particle size regardless of the raw material and production method, 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. If it is irregular or has a fiber shape
It is also appropriate in terms of the shape. Also, chemical activated carbon may have a higher impurity content than gas activated carbon,
If this impurity is too much, it may hinder the formation of a hollow activated carbon molded product. A molded product is obtained. In addition, the particulate thermoplastic resin is arranged in the activated carbon powder, and the activated carbon powder exists at a thickness equal to or greater than the thickness of the hollow activated carbon molded product to be obtained around the particulate thermoplastic resin. do it.

[0008] As described above, the heat treatment is performed by performing an infusibilization treatment in which the temperature is increased from room temperature to 250 to 350 ° C in an oxidizing atmosphere such as air or oxygen depending on the type of the particulate thermoplastic resin, and then the particulate heat is applied. Directly up to the temperature at which the plastic resin is carbonized, without firing in an inert gas such as nitrogen or argon, or in a non-oxidizing atmosphere such as in a vacuum, or without infusibilizing in an oxidizing atmosphere. Or baking treatment. Here, the baking treatment, when using the above-mentioned as the particulate thermoplastic resin, generally,
A few hundred degrees Celsius is sufficient. An activation treatment may be performed as necessary. After the heat treatment, excess activated carbon powder is removed by a sieve or the like to obtain a hollow activated carbon molded product.

The hollow activated carbon molded article obtained in this manner has a carbide skeleton that is present abundantly inside helps to maintain a hollow shape, and the carbide skeleton gradually decreases toward the outer surface. Activated carbon powder is supported by almost point contact. Therefore, most of the surface of the hollow activated carbon molded product is made of activated carbon powder, and the activated carbon function is kept good. Further, since the hollow portion communicates with the outside world, gas or the like enters this hollow portion, and the activated carbon in a wide range inside and outside exhibits its function. Furthermore, although the hollow activated carbon molded product of the present invention is light in weight, it is not powdery, so that the handleability is very good. The mechanism by which the hollow activated carbon molded product is formed is not clear, but at least the surface of the particulate thermoplastic resin disposed in the activated carbon powder is once melted by heat treatment to become fluid and becomes active carbon. The powder particles are adhered one after another, and thereafter, the particulate thermoplastic resin remains as a carbide to serve as a binder, and a hollow activated carbon molded article in the shape of the used particulate thermoplastic resin is formed. Conceivable. Where the particles
Thermoplastic resin melts and the whole is activated carbon powder
Hollow if it does not remain inside, such as used for attaching particles
The hollowness of the part will be high, and regardless of melting
Partially adhered activated carbon powder particles
If it remains inside without being used for
Relatively low hollowness, such as a mesh-like space
Become.

[0010] As described above, the hollow activated carbon molded product obtained by the present invention has excellent activated carbon function as it is,
In addition, although the handleability is good, other functions other than the activated carbon function can be added by filling the hollow portion with another substance. For example, if the hollow part is filled with pesticides or pesticides, etc., they are once adsorbed on the outer activated carbon and then gradually released, so that they can be used with sustained-release pesticides and pesticides that can maintain their effects for a long time. Become. Here, as a method of filling the hollow portion with another substance, a general method such as immersing a hollow activated carbon molded product in a solution containing the substance to be filled can be used.

[0011]

【Example】

<Example 1> Flow beads CL-12007 (spherical polyethylene manufactured by Sumitomo Seika Co., Ltd .: particle size range: 900 to 1)
100 μm) was placed in Kurare-coll PK100 (powder activated carbon manufactured by Kuraray Chemical Co., Ltd .: particle size: 100 mesh or less), and then raised from room temperature to 300 ° C. in air at a rate of about 2 ° C./min. After performing the infusibilization treatment of maintaining the temperature at 300 ° C. for 1 hour,
A firing treatment was performed for one hour. After the heat treatment, excess activated carbon powder was removed by sieving to obtain a true spherical hollow activated carbon molded product.

<Example 2> In Example 1, the flow beads CL-12007 used were replaced with the flow beads CL-5.
A completely spherical hollow activated carbon molded product was obtained in the same manner as in Example 1 except that 007 (spherical polyethylene manufactured by Sumitomo Seika Co., Ltd .: particle size range: 300 to 400 μm) was used.

<Embodiment 3> In Embodiment 1, the flow beads CL-12007 used were replaced with UBE: B-128.
(Cylindrical polyethylene pellets manufactured by Ube Industries, Ltd .:
Diameter, about 5 mm, height: about 3 mm), and Kuraray Coll PK100 was replaced by Kuraray Coll PK30 (powder activated carbon manufactured by Kuraray Chemical Co., Ltd .: particle size: 30 mesh or less). In the same manner as in Example 1, a cylindrical hollow activated carbon molded product was obtained.

<Embodiment 4> In Embodiment 1, the flow beads CL-12007 used were replaced by TORAY: AQ-N.
YLON, P-20 (a rectangular parallelepiped water-soluble nylon pellet manufactured by Toray Industries, Inc .: length, width: about 4 mm, height: about 3 mm)
In the same manner as in Example 1 except that the above process was repeated, a substantially rectangular hollow activated carbon molded product was obtained.

<Example 5> In Example 1, the flow beads CL-12007 used were molded into a cylindrical polyvinyl chloride resin pellet (diameter: about 3 mm, height: about 4).
mm), and heat-treated in a nitrogen atmosphere from room temperature to 600 ° C. at a rate of about 2 ° C./min.
A cylindrical hollow activated carbon molded product was obtained in the same manner as in Example 1 except that the firing treatment was maintained for 1 hour.

<Example 6> All of the examples were the same as in Example 1 except that the used KURARECOL PK100 was replaced by Diasorb F200 (powder activated carbon manufactured by Mitsubishi Chemical Corporation: particle size: 200 mesh or less). In the same manner as in Example 1, a true spherical hollow activated carbon molded product was obtained.

<Comparative Example> A cylindrical phenol resin pellet (diameter: about 3 mm, height: about 4 mm) for molding the flow beads CL-12007 used in Example 1 was used.
All were the same as Example 1 except that What was obtained was merely a carbide of a phenol resin.

[0018]

According to the present invention, it is possible to obtain a desired hollow activated carbon molded article having various activated carbons having excellent activated carbon functions, light weight and good handleability without any complicated production steps. it can.

Claims (1)

(57) [Claims] 1. A method comprising: using a particulate thermoplastic resin and activated carbon powder; disposing the particulate thermoplastic resin in the activated carbon powder; and melting and carbonizing at least the surface of the particulate thermoplastic resin once. A method for producing a hollow activated carbon molded product characterized by having a large amount of carbide on the inside and a large amount of activated carbon powder on the outside.