JP2901191B2 - Air purifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an air purifying agent, and is particularly effective for removing tobacco smoke and odor in the air.

[Prior Art] Several air purifying agents in which aniline and an aniline salt are added to activated carbon have already been filed. JP-A-56-53744 discloses that activated carbon has 3 to 30% by weight of aniline.
It is described that the impregnated air purifier is effective as a remover for aliphatic aldehydes. JP 63-28364
No. 6 describes that a mixture of activated carbon impregnated with aniline and activated carbon impregnated with malic acid, iron salt, and aniline has a great effect for removing odors such as acetaldehyde, lower amine, and hydrocarbon. In addition, the present inventor describes in Japanese Patent Application No. 63-175994 that an air purifying agent obtained by adhering one or more inorganic acid aniline salts to a porous substance such as activated carbon is effective for removing the odor of tobacco. did.

[Problems to be Solved by the Invention] Activated carbon is a unique material having excellent adsorptivity as a nonpolar adsorbent, and exhibits high adsorptivity to almost all gaseous substances.

The malodors generated in living spaces such as offices and homes include lower aliphatic aldehydes such as acetaldehyde, ammonia, lower amines, hydrocarbons, hydrogen sulfide, and methyl mercaptan in composition. A typical example is the odor generated when smoking tobacco.
Activated carbon is effective in removing and removing these odorous substances,
However, it is difficult to completely remove lower aliphatic aldehydes, ammonia, lower amines and the like among the above-mentioned malodorous substances. For this reason, many impregnated carbons are produced and used. These impregnated carbons have significantly improved adsorbability to these substances as compared with ordinary activated carbon. However, coupled with the fact that the human sense of smell is sharp, there has been a demand for an air purifying agent which is difficult to completely remove malodor and has a higher adsorptivity.

[Means for solving the problems] These impregnated carbons as described in the section of the prior art significantly improve the adsorptivity to lower aliphatic aldehydes and the like as compared with ordinary activated carbon, but first adjust the impregnated carbon. It was noticed that the adsorption properties varied considerably from batch to batch. In some batches a slight amine odor was sometimes felt. As a result of examining the relationship between the method of adjusting the impregnated carbon and the adsorptivity, it was found that the adsorptivity was significantly lowered when the activated carbon was not sufficiently washed before impregnation and the PH was high. Based on this, the inventors further studied the relationship between water washing and pickling with water, and as a result, arrived at the present invention.

That is, it is an air purifier obtained by washing activated carbon with water until the pH becomes 9.0 or less, or washing with an aqueous acid solution, and then adhering a copper aniline complex.

 Hereinafter, the present invention will be described in detail.

The activated carbon used here generally has a large surface area of several hundred m ³ or more per gram, and can be used in a wide range as long as it is a carbon material having high adsorptivity. As the raw material of the activated carbon, a carbide such as coconut shell or wood or coal is usually used, but any material may be used. Also, the activation method may be obtained by any method such as treatment with steam or carbon dioxide at a high temperature or treatment with zinc chloride, phosphoric acid or concentrated sulfuric acid.

The effect can be recognized with any of crushed charcoal, granulated charcoal or granulated charcoal. However, a sheet-shaped adsorbent to which granulated charcoal or activated carbon is attached is convenient in terms of pressure loss and replacement. The granulated coal is prepared by adding 30 to 60 parts of petroleum pitch or coal tar or the like as a binder to 100 parts of a carbon material according to a conventional method, mixing and activating the mixture, followed by activation.

Next, the activated carbon used in the present invention must be washed with water until the pH becomes 9.0 or lower or with an aqueous acid solution. When washing with water, the pH gradually decreases by immersing in water for washing. It is usually 10 to 11 before washing, but it can be lowered to about 8.5 with sufficient washing. In the present invention, the pH of activated carbon after washing needs to be 9.0 or less,
This is because if the washing is insufficient, the adsorbability of malodorous gas such as acetaldehyde decreases. In the case of washing with an aqueous acid solution, the type of acid is not particularly limited, but when washing with substantially the same acid concentration, the amount of alkali metal salts, alkaline earth metal salts, and iron salts remaining in the activated carbon is reduced to check the washing effect. Hydrochloric acid is the most effective when examined. A substantially similar relationship is also recognized for the effects of the present invention. Accordingly, hydrochloric acid is preferred as the acid. The concentration of hydrochloric acid is not particularly limited, but the cleaning effect is recognized even at a relatively low concentration.
0.3 to 1.0 is preferable.

In the present invention, it is necessary to impregnate a copper aniline complex onto the activated carbon washed as described above. At this time, it is preferable that the activated carbon after washing is once dried and then attached. In order to attach the copper aniline complex (CuCl ₂ · NH ₂ C ₆ H ₅ ) to the activated carbon, the aqueous solution can be sprinkled on the activated carbon to uniformly impregnate it and then dried to adjust.

[Action / Effect] Washing or pickling with water is very effective in removing lower aliphatic aldehydes, which is one of the remarkable effects of the present invention, as will be specifically shown in the embodiments described later. Although the mechanism of action is not sufficiently clear, it is recognized that washing with water or pickling with water reduces the pH of activated carbon and the content of alkali metal salts, alkaline earth metal salts, iron salts and the like. On the other hand, since the adsorbent of the present invention is required to contain a copper aniline complex as an essential requirement, the removal of these salts lowers the pH of the activated carbon and the supported copper aniline complex is in a stable state. Is also considered to be one of the reasons. However, even if the water is washed sufficiently, the degree of decrease in PH and the content of inorganic salts is not as high as that of pickled water,
It is noteworthy that the acetaldehyde adsorptivity is not much different from that of the pickled product.

For example, the specific surface area adjusted by a conventional method is 1.150 m ² / g,
Activated carbon having a specific gravity of 0.405 was immersed in water at room temperature for 2 to 3 hours and washed sufficiently, and immersed in 0.5 N hydrochloric acid for 2 to 3 hours, washed sufficiently with stirring, and washed with water. The analytical values of activated carbon and unwashed products prepared by drying these are shown in the following table.

Samples were prepared by impregnating these activated carbons with 8% aniline by a dipping method.

Acetaldehyde gas concentration of 1000 at room temperature
FIG. 1 shows the relationship between the standing time and the amount of adsorbed acetaldehyde when left in an atmosphere containing ppm.

Activated carbon washed with water or pickled water has a significantly higher adsorption amount than unwashed products. However, there is hardly any difference between the washed product and the pickled product.

In these tests, almost the same results are obtained when a copper aniline complex is added instead of aniline and when aniline phosphate is added.

FIG. 2 shows the isothermal adsorption line of acetaldehyde gas of the sample prepared as described above. This indicates that, particularly when the gas concentration is low, activated carbon washed with water or pickled water has significantly higher adsorptivity than unwashed products.
In these tests, almost the same results are obtained when a copper aniline complex is added instead of aniline and when aniline phosphate is added.

This indicates that impregnated aniline on activated carbon or acid-washed activated carbon that has been sufficiently washed can be an excellent adsorbent for removing odor from tobacco. In addition, almost the same results are obtained when a copper aniline complex is added instead of aniline.

(Embodiment of the invention) Specific surface area adjusted by a conventional method 1.
Activated carbon with a filling density of 0.405, 150 m ² / g, immersed in water at room temperature for 2 to 3 hours, washed thoroughly, and 2 in 0.5 N hydrochloric acid
After immersion for about 3 hours, the mixture was thoroughly washed with stirring and washed with water. The analysis values of the activated carbon and the unwashed product prepared by drying them are the same as those shown in Table 1 above.

A copper aniline complex was added to these activated carbons by immersion method.
The sample with% impregnation was prepared.

Acetaldehyde gas concentration of 1000 at room temperature
The relationship between the standing time and the amount of adsorbed acetaldehyde and the isotherm adsorption line when left in an atmosphere containing ppm are almost the same as those shown in FIGS. 1 and 2 above. Adsorbed amount is remarkably higher than washing products. However, there is hardly any difference between the washed product and the pickled product.

[Brief description of the drawings]

FIG. 1 shows the relationship between the adsorption time of activated carbon impregnated with 8% aniline and the amount of adsorbed acetaldehyde. 1 Activated carbon not washed 2 Activated carbon washed 3 Activated carbon pickled with water Fig. 2 shows an isothermal adsorption line of acetaldehyde gas of activated carbon impregnated with 8% of aniline. 1 Activated carbon not washed 2 Activated carbon washed 3 Activated carbon washed with acid

Claims (1)

(57) [Claims] 1. An air purifier comprising washing activated carbon with water until the pH becomes 9.0 or lower, or washing with an aqueous acid solution, and then adhering a copper aniline complex.