JP2565711B2 - Method for manufacturing activated carbon molded product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a method for producing an activated carbon molded product that is required to have an activated carbon function and gas permeability, for example, used for electrodes, filters, catalyst carriers of air batteries.

(Prior art and its problems) Generally, an organic binder that is carbonized by firing such as various synthetic resins is kneaded with activated carbon and other materials used as necessary, and firing treatment is performed to produce an activated carbon molded product. are doing. It is used as a gas passage to the activated carbon in which the fine pores that are naturally formed during the carbonization of the organic binder by firing are dispersedly contained.

However, it is probably because the surface of the activated carbon is covered with a carbon skeleton, but it is difficult to obtain a sufficient activated carbon function.

Therefore, the applicant of the present application has previously filed an application to greatly improve this problem by using activated carbon precoated with a depolymerizable organic substance (Japanese Patent Laid-Open No. 60-204610).
issue).

The present invention has made it possible to achieve a greater effect.

(Means for Solving Problems) In the present invention, an organic binder that carbonizes by firing and activated carbon are used as at least main materials, and after kneading and molding, firing is performed to produce an activated carbon molded product, before kneading. Of the activated carbon is adhered to the outer surface of a substance (hereinafter, referred to as “substance A”) that diffuses or is consumed at a temperature at which the organic binder starts decomposing and carbonizing, and is attached to the outer surface of the activated carbon. Also, the gist is a method for producing an activated carbon molded article, which comprises depositing a substance (hereinafter, referred to as “substance B”) which is diffused or consumed at a temperature at which the organic binder starts to decompose and carbonize.

 The details will be described below.

As the organic binder, there are various kinds of selection objects such as natural and synthetic resins, rubber, thermosetting initial condensate, pitch, tar, and asphalt. For example, styrene resin,
Acrylic resin, urea resin, melamine resin, polyester resin, furan resin, polyvinyl alcohol, polyacrylamide, butyl rubber, chlorinated polyvinyl chloride, chlorinated polyethylene, polyvinyl chloride, etc., as appropriate 1
They can be used alone or in combination of two or more.

Activated carbon can be appropriately used irrespective of the raw material and the manufacturing method, but the particle size is preferably 100 μm or less because it has a relationship with the particle size of the substance that adheres the activated carbon to the outer surface.

Examples of the substance A and the substance B are various inorganic salts such as carbonates, nitrates, sulfates and phosphates, polyethylene, polypropylene, polybutadiene, polyisobutylene, polystyrene, polymethamethylstyrene, polymethylmethacrylate, Examples thereof include depolymerized organic substances such as ethyl polyethacrylate, polyacrylic acid ester, poly-α-deuterostyrene, and nylon. These may be appropriately selected and used according to the type of the organic binder, but in many cases, the volume shrinkage of the molded product during firing almost completes up to about 300 ° C, so that it is possible to use up to about 300 ° C. It is generally preferable that the material is less likely to be consumed. In this respect,
Considering that the residual amount after firing is small, polymethylmethacrylate, polyacrylic acid ester, and nylon are preferred examples. The substance A and the substance B may be of the same type or different types.

In order to attach the activated carbon to the outer surface of the substance A and to attach the substance B to the outer surface of the activated carbon, for example, first, a general method using a ball mill, a sand mill, a mixer, a roll mill, a kneader, or recently After the activated carbon is first attached to the outer surface of the substance A by using a hybridization system or the like as a mechanochemical method which is receiving attention, the substance B is similarly attached to the outer surface of the activated carbon, or After the substance B is first attached to the outer surface of the activated carbon by a microcapsulation method such as a powder bed method or a kneading method in which a plasticizer, a solvent and the like are used together as needed, the substance B is removed from the outside of the substance A. It may be attached to the surface. By the way, when the activated carbon that does or does not attach the substance B to the outer surface is attached to the outer surface of the substance A,
It is advisable not to apply too high a shearing force. That is, as the substance A, from the viewpoint of the strength of the molded product and the adhesiveness to the activated carbon, it is about 10 to 100 times the particle size of the activated carbon, and the absolute dimension is 1
It is preferable that the diameter be less than mm, but if too much shearing force is applied during adhesion, the desired particle size ratio will change significantly due to crushing. Further, when the substance B is attached to the outer surface of the activated carbon first, the relative kneading ratio between the activated carbon and the substance B can be easily changed, so that it seems that the kneading is the simplest method.

The activated carbon treated product thus obtained is kneaded with an organic binder, a stabilizer used as necessary, a solvent, graphite, etc. in a kneader, a three-roll mill, etc. to obtain a plate shape, a column shape, a honeycomb shape or the like. After being formed into the shape of, and if necessary, dried and then subjected to a heat treatment of firing to carbonize the organic binder.
At this time, when the substances A and B are exhausted, the rapid heating rate may cause cracking or swelling of the molded product. Is desirable. The firing can be performed in an appropriate non-oxidizing atmosphere such as an inert gas atmosphere, a reducing atmosphere, or a vacuum atmosphere, and the maximum temperature is usually about 600 ° C to 900 ° C.

After firing, activation treatment or the like is further performed as necessary to obtain an activated carbon molded product.

(Function) The substances A and B are diffused and exhausted to form a relatively large space in which the activated carbon is distributed inside the molded product and a path for connecting the space and the external environment of the molded product. In this state, the activated carbon is separated from the activated carbon by the force applied during the kneading process of the attached substance B, for example, during the kneading process, or the adherence of the activated carbon and the organic binder to each other originally occurs. By not completely separating the activated carbon, the activated carbon adheres to the organic binder at a small area on the outer surface thereof.

The peripheral portion of the above-mentioned space is composed of a carbonized organic binder or a residual material, and therefore, is relatively rich in irregularities.

Therefore, it is probably distributed around the space with a small contact area.

In other words, the activated carbon exists inside the molded product in a portion having good communication with the outside world, and the outer surface is sufficiently utilized.

From the above facts, the present inventor speculates that the activated carbon function of the molded article obtained by the present invention may be sufficiently exhibited.

(Example) Hereinafter, "parts" means "parts by weight".

[Example 1] (1) Activated carbon treatment Diasorb F100 (powdered activated carbon manufactured by Mitsubishi Kasei Co., Ltd .:
Particle size 200 mesh or less) 50 parts, Acrisilup SY-103
(Mitsubishi Rayon Co., Ltd. polymethylmethacrylate) and methyl ethyl ketone were soaked in a 1: 2 solution.
After leaving it for 0 minutes, take it out, and dry it immediately. Then, polymethylmethacrylate beads (Mitsubishi Rayon Co., Ltd .: particle size)
20 parts of 0.5-1.0 mm sphere was mixed with a ball mill for about 1 hour.

(2) Manufacture of activated carbon moldings Activated carbon treated in (1) 85 parts Polyvinyl chloride resin 40 parts Dioctyl phthalate (plasticizer) 15 parts Stearate (stabilizer) 2 parts Methyl ethyl ketone 30 parts After kneading for 15 minutes, extrusion molding was performed to obtain a rod-shaped molded product having a diameter of about 5 mm. After heating this in air from room temperature to 300 ℃ at a heating rate of about 2 ℃ / minute,
An activated carbon molded product was obtained by performing a calcination treatment at 850 ° C. for 1 hour in a closed container.

Example 2 Acrylic bead polymer (polyacrylic acid ester manufactured by Mitsubishi Rayon Co., Ltd .: one obtained by sizing to a particle size of 0.5 to 1.0 mm) was used in place of the polymethylmethacrylate beads in Example 1. All were the same as in Example 1.

[Comparative Example 1] In Example 1, activated carbon, acryl wrap SY-103,
All were the same as in Example 1 except that the polymethylmethacrylate beads were used separately without the treatment in (1).

[Comparative Example 2] Comparative Example 2 was performed in the same manner as Comparative Example 1 except that acrylic bead polymer was used instead of polymethylmethacrylate beads.

[Comparative Example 3] The activated carbon treated in (1) in (2) of Example 1
All were the same as in Example 1 except that instead of using 85 parts, 50 parts of activated carbon without any treatment were used.

(Effects of the Invention) Table 1 shows the evaluation results of the products obtained in each example.
The specific surface area was measured by the BET method, and the adsorption capacity was measured by decolorizing methylene blue according to JIS K1470.

As can be seen from Table-1, according to the present invention, it is possible to obtain an activated carbon molded product having an excellent activated carbon function.

Claims (1)

(57) [Claims] 1. An activated carbon before kneading is used to produce an activated carbon molded article by kneading, molding and firing after using an organic binding agent carbonized by firing and activated carbon as at least main materials. Is attached to the outer surface of a substance that dissipates or consumes above the temperature at which decomposition carbonization begins,
Also, a method for producing an activated carbon molded article, characterized in that a substance which is vaporized or consumed at a temperature equal to or higher than a temperature at which the organic binder starts to be decomposed and carbonized is attached also to an outer surface of the activated carbon.