JP2841668B2 - Method for manufacturing activated carbon moldings - Google Patents

Description

Description: TECHNICAL FIELD 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 requires an activated carbon function and a gas passing ability.

(Prior Art) Various methods for producing an activated carbon molded product by using at least an organic binder to be calcined and carbonized and activated carbon as main materials and performing a calcination treatment are known. The shape to be obtained also varies, such as a particle shape.

(Problems to be Solved by the Invention) Activated carbon in the form of particles and the like can be excellent in handling property as compared with activated carbon in powder form. But,
Attempting to use activated carbon present inside to make it functionally superior results in poor strength, and does not exhibit the advantage of handleability sufficiently.

One example is the case of forming a hollow activated carbon molded product. The hollow activated carbon molded product, the organic binder and the activated carbon as described above, after the organic binder as a core material such as particulate matter that is diffused and consumed above the temperature at which decomposition and carbonization starts, after being fixed to the surface thereof, It can be obtained by performing a baking treatment. And, by being hollow, simply using an organic binder and activated carbon as main materials, forming a kneaded product, and having a similar appearance shape as compared with that obtained by performing a baking treatment Even so, the activated carbon function is excellent. However, the strength is extremely low, and depending on the size and the degree of hollowness, the strength may be large enough to be easily crushed with a fingertip.

Thus, the present invention provides a molded article excellent in activated carbon function, such as when a hollow activated carbon molded article is obtained by using the above-mentioned core substance, and greatly suppresses a decrease in strength without substantially adversely affecting the function improvement. The aim is to provide a method.

(Means for Solving the Problems) The present invention uses at least an organic binder to be calcined and carbonized as an active carbon and a calcining treatment to produce an activated carbon molded product. The gist of the present invention is a method for producing an activated carbon molded product, characterized by using a fine powder of (1) on the surface.

The details will be described below. In addition, as a means for improving the function, there is a method of obtaining a kneaded material containing a pore-forming material in a dispersed manner and increasing the porosity by calcining the kneaded material. It will be described according to the case.

First, activated carbon can be used as appropriate, regardless of the raw material, production method, or the like. At the time of the baking treatment, a material that becomes activated carbon may be used. The size is also appropriate, but if it is up to about 200 μm, the uniformity is excellent.

A fine powder of silicic anhydride is put on the surface of the activated carbon. A commercially available colloidal silica or the like as a colloidal aqueous solution of silicic anhydride may be used. Examples of commercially available products include "Snowtex" (manufactured by Nissan Chemical Industries, Ltd.) and "Ludox" (manufactured by DuPont). Others
Monsanto products are also available. It can be used after being diluted to an appropriate concentration. Activated carbon is immersed in these, and after removing the excess, it is easy to dry by air drying or heating. Here, appropriate impregnation such as heat impregnation and vacuum impregnation can be performed.

In addition, as the organic binder, natural and synthetic resins, rubber, thermosetting initial condensate, pitch, tar, asphalt and the like can be variously selected. As an example, a styrene resin,
Acrylic resin, urea resin, melamine resin, polyester resin, furan resin, polyvinyl alcohol, polyacrylamide, butyl rubber, chlorinated polyethylene, polyvinyl chloride, polyvinylidene chloride and the like can be mentioned. 1 as appropriate
These are used alone or in combination of two or more.

Activated carbon and organic binder with fine powder of these silicic anhydrides, as well as stabilizers used if necessary, are attached to the core material which is scattered and consumed above the temperature at which the organic binder starts to decompose and carbonize. Obtain what has become a thing. The size is appropriate, for example, relatively small for home or personal use such as deodorization in a refrigerator or a drinking water filter, and relatively large for large-scale use such as factory exhaust. However, in general, it is preferable to set the diameter to about 0.1 mm to about 10 mm.

Here, as the core substance, for example, carbonate, nitrate,
Various inorganic salts such as sulfates and phosphates, polyethylene,
Polypropylene, polybutadiene, polyisobutylene,
Examples include depolymerizable organic substances such as polystyrene, polymethmethylstyrene, polymethyl methacrylate, polyethyl methacrylate, polyacrylate, poly-α-douterostyrene, and nylon. These are appropriately selected and used according to the type of the organic binder. However, in many cases,
Since the shrinkage of the molded product due to the decomposition and carbonization of the organic binder is almost completed up to about 300 ° C., it is generally preferable that the material does not cause much air diffusion and consumption up to about 300 ° C. Examples of satisfying this condition include polyethylene, polymethyl methacrylate, polyacrylate, and nylon. When attaching to the core material, use a ball mill,
A sand mill, a mixer, a roll mill, a kneader, or the like may be used, or an encapsulation method using a hybridization system as a mechanochemical method that has recently attracted attention may be used. In addition, in terms of dimensions, if the core material is at least five times larger than the activated carbon, the sticking property is generally good. In addition, when wearing, it is appropriate to treat the activated carbon and the organic binder at the same time, or to wear the organic binder first, then wear the activated carbon, etc. it can. Further, the material attached to the core material in this manner can be newly applied to the core material as treated activated carbon. Incidentally, as the amount of the organic binder and the activated carbon attached to the core substance increases, as the amount becomes relatively small, the more the activated carbon function and the strength become, the better. In addition, in the case of wearing by dry processing without using a solvent or the like, if the weight sum of the activated carbon and the organic binder is set to about 60% of the core substance, the degree of fixation generally becomes high.

The obtained particulate matter is subjected to a baking treatment for carbonizing the organic binder. Drying or the like may be performed in advance as needed.
The heating rate is determined by taking into account the occurrence of cracks and swelling. The maximum temperature depends on the atmosphere to be treated, such as an inert gas atmosphere, a reducing atmosphere, a vacuum atmosphere, etc., but usually 700 to 1100
° C, preferably about 800-1000 ° C. After a relatively low temperature treatment up to about 700 ° C., the atmosphere can be changed and the treatment can be performed again. After this high-temperature heat treatment, activation treatment or the like is performed as necessary. In addition, other adsorbents such as silica gel and zeolite, antibacterial substances such as silver, and the like can be used in combination.

(Action) The fine powder of silicic anhydride that has arrived on the activated carbon surface is fused with each other on the activated carbon surface and has a porous structure by the high-temperature treatment. As a result, the strength of the activated carbon molded product is increased, and the gas passing ability required for the activated carbon function is secured.

(Embodiment) Hereinafter, the term “parts” means “parts by weight”.

<Example 1> (1) Activated carbon treatment 20 parts of Kuraray Coal PK (powdered activated carbon manufactured by Kuraray Chemical Co., Ltd .: particle size of 200 mesh or less) was added to Snowtex 2
0 (colloidal silica manufactured by Nissan Chemical Industries, Ltd .: silicic anhydride; particle size: 10 to 20 μm, content: about 20%), immersed in 40 parts, and then separated by filtration to remove the surplus. 110
Heat drying at ℃.

(2) Production of Hollow Activated Carbon Molded Product 40 parts of Flowbead CL-5007 (spherical polyethylene manufactured by Sumitomo Seika Co., Ltd .: particle size range: 250 to 500 μm) were converted to polyvinyl chloride resin (manufactured by Denki Kagaku Kogyo Co., Ltd.). : Particle size range 20-50μ
m) The mixture was mixed with 10 parts by a ball mill for about 1 hour, and 15 parts of the activated carbon prepared in (1) was added thereto, followed by further mixing for 1 hour. After removing excess activated carbon and polyvinyl chloride resin,
The temperature was raised from room temperature to 300 ° C. in air at a rate of about 5 ° C./min, and further fired at a maximum temperature of 800 ° C. for 1 hour in a closed container.

<Example 2> In Example 1, in place of Snowtex 20, Snowtex 40 (colloidal silica manufactured by Nissan Chemical Industries, Ltd .: silicic anhydride; particle diameter: 10 to 20 µm, content: about 40%) was used. Except for this, all procedures were the same as in Example 1.

<Example 3> In Example 1, all were the same as Example 1 except that Snowtex 20 was used after diluting it twice with water.

<Example 4> In Example 1, in place of Snowtex 20, Snowtex 20L (colloidal silica manufactured by Nissan Chemical Industries, Ltd .: silicic anhydride; particle diameter: 40 to 50mμ, content: about 20%) was used. Except for this, all procedures were the same as in Example 1.

<Example 5> In Example 1, instead of using a ball mill,
Hybridization of 40 parts of Flowbead CL-8007 (Spherical polyethylene manufactured by Sumitomo Seika Co., Ltd .: particle size range of 500 to 850 μm) with 10 parts of polyvinyl chloride resin (manufactured by Sumitomo Chemical Co., Ltd .: particle size range of 50 to 80 μm)・ After processing at 8000 rpm for 5 minutes by the system (manufactured by Nara Machinery),
To this, add 15 parts of activated carbon prepared in (1), and add 8000 rpm,
Everything was the same as Example 1 except that the treatment was performed under the condition of 5 minutes.

<Example 6> In Example 5, as a treatment by the hybridization system, 5 parts of polyvinyl chloride resin and activated carbon 8 prepared in (1) were used for 40 parts of flow beads CL-8007.
Everything was performed in the same manner as in Example 5 except that the parts were alternately processed twice.

<Example 7> In Example 5, 10 parts of polyvinylidene chloride resin (manufactured by Kureha Chemical Industry Co., Ltd .: particle size range of 50 to 100 µm) was used as the treatment by the hybridization system, and (1)
After processing and integrating 15 parts of activated carbon prepared in advance, and then treating this with 40 parts of flow beads CL-8007,
All operations were the same as in Example 5.

<Comparative Example 1> In Example 1, instead of the activated carbon prepared in (1),
All operations were the same as in Example 1 except that the activated carbon without the treatment of (1) was used.

<Comparative Example 2> 28 parts of polyvinyl chloride resin (described above) and Kuraray Coal PK35
Parts and 10 parts of dioctyl phthalate (plasticizer) are kneaded in a kneader for about 30 minutes, and then a granule having a diameter of about 500 μm is obtained by a granulator. Was given.

Table 1 shows the evaluation results of the results obtained in each example. The specific surface area was measured by the BET method. In addition, the adsorption ability was determined by measuring the decolorization ability of methylene blue according to JIS K 1470. The strength is an evaluation based on the number of crushes when crushed by a finger, 指: crushing rate is less than 10%, ：: crushing rate is 10%.
More than ~ 30%, △: Crush rate 30% ~ 50%, ×:
The crushing rate is 50% or more.

(Effects of the Invention) As described above, according to the present invention, it is possible to produce an activated carbon molded product that has an excellent activated carbon function, has strength, and can sufficiently exhibit good handleability.

Claims (1)

(57) [Claims] 1. A method for producing an activated carbon molded product by using at least an organic binder to be calcined and carbonized and an activated carbon as a main material and performing a calcination treatment, wherein fine powder of silicic anhydride is previously applied to the surface as the activated carbon. A method for producing an activated carbon molded product, characterized in that the product is used.