JPS63147542A - Air cleaning agent - Google Patents

Abstract

PURPOSE:To enhance the deodorizing capacity of the title agent in the living environment in offices, households, etc., by preparing the air cleaning agent from a mixture of the activated carbon deposited with aniline and the activated carbon deposited with malic acid and an iron salt. CONSTITUTION:Activated carbon is dipped at ordinary temp. in an aq. aniline soln. for 2-3hr, filtered, and the dried, or an aniline-contg. gas is passed through an activated carbon-packed tower to adsorb the aniline on the carbon. The activated carbon deposited with aniline is thus obtained. Meanwhile, activated carbon is dipped in a liq. mixture of malic acid and an iron salt to sufficiently adsorb the materials in the pores, then filtered, and dried, or the soln. is sprinkled over the carbon to sufficiently impregnate the carbon with the soln. The activated carbon deposited with malic acid and an iron salt is thus obtained. Both kinds of the obtained activated carbon are mixed to prepare the adsorbent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air purifying agent, and is particularly effective in removing tobacco odor from indoor air in offices, homes, and the like.

[Prior Art] An adsorbent in which activated carbon is impregnated with aniline is disclosed in Japanese Patent Publication No. 60-54095. Activated carbon impregnated with aniline in an amount of 3 to 30% by weight (based on activated carbon) is effective for the removal of formaldehyde and acetaldehyde in the gas phase. It is described that it is effective in adsorbing lower aliphatic aldehydes such as. In addition, JP-A-57-99 describes the use of iron salts for deodorization.
318 and 57-113826 disclose a method of adding a polymeric substance to a colloidal solution containing an iron salt to stabilize the solution and maintain its effect.
-156539 discloses that L-
A method of stabilizing the solution and improving its deodorizing power by adding ascorbic acid is described.

Furthermore, Japanese Patent Application Laid-Open No. 58-26810 describes the use of activated carbon impregnated with an organic acid as a deodorizing agent, and it is stated that adsorption of ammonia is significantly enhanced by impregnating activated carbon with citric acid. ing.

[Problems to be Solved by the Invention] Activated carbon is a unique material that has extremely excellent adsorption properties as a nonpolar membrane adhesive, and exhibits high adsorption properties for almost all gaseous substances. Indoor air in living spaces such as offices and homes usually has a strong odor of tobacco, and its composition includes acetaldehyde, ammonia, lower amines, hydrocarbons, hydrogen sulfide, and the like. The term cigarette odor here refers to the odor of gas that is emitted when smoking. In particular, the ratio of ammonia, which is a weak point in adsorption activity, is high, and there is also a relatively large amount of lower aliphatic aldehydes, so it is difficult to remove the odor with ordinary activated carbon alone. There was a need for an adsorbent that would completely remove it.

[Means for Solving the Problems] The present inventors have studied compositions with various impregnation activities and deodorizing properties when they are combined. The results showed that aliphatic lower aldehydes can be completely removed by adding activated carbon impregnated with aniline, and that the synergistic effect on ammonia adsorption is further promoted by adding activated carbon impregnated with malic acid and iron salt. Based on this discovery, the present invention was completed.

The present invention will be explained in detail below.

The activated carbon used here is usually several tens of gram per gram.
A wide range of carbon materials can be used as long as they have a large surface area of 0f+ (or more) and exhibit high adsorption properties.The raw material for activated carbon is usually fossil fuels such as coconut shells or wood, or coal, but any of them can be used. Also, the activation method may be one obtained at high temperature using steam or carbon dioxide, or by treatment with zinc chloride, phosphoric acid, concentrated sulfuric acid, or the like.

Although the effect can be recognized in any form of crushed coal, granulated coal, or granulated coal, a sheet-like adsorption layer impregnated with granulated carbon or activated carbon is convenient in terms of handling such as pressure loss and replacement. Granulated coal is prepared by adding 30 to 60 parts of petroleum pitch or coal tar as a binder to 100 parts of carbon material, mixing and molding, and then activating the mixture in accordance with a conventional method.

Activated carbon impregnated with aniline exhibits extremely high adsorption ability for lower aliphatic aldehydes such as formaldehyde-acetaldehyde, and the amount of impregnation is not particularly limited. Activated carbon also exhibits high adsorption properties for aniline, and since the aniline is adsorbed and retained within its pores, the vapor pressure is significantly suppressed and generally no odor is felt.

However, if the amount of impregnation is too high, there is a risk that some of the aniline will be desorbed, and if the amount is too small, the effect of impregnating aniline will be poor, so a range of 3 to 30% by weight is more preferable.

To impregnate activated carbon with aniline, the activated carbon is immersed in an aniline aqueous solution at room temperature for 2 to 3 hours, and then washed separately.

In addition to the method of drying, it can also be adjusted by passing a gas containing aniline through an activated carbon-filled bed and adsorbing it in the gas phase.

Activated carbon impregnated with malic acid and iron salt exhibits high adsorption properties for ammonia and amines, and the impregnated amount is not particularly limited. However, if the amount of malic acid impregnated is small, the effect is poor, and if the amount of impregnated increases, there is a marked tendency to inhibit the adsorption ability of activated carbon for other substances, so the amount of malic acid impregnated is preferably 5 to 30% by weight.

Iron salts are widely recognized to be effective in adsorbing ammonia, and the types are not limited, but for handling reasons, ferrous sulfate is recommended.

Ferric sulfate, ferrous chloride, ferric oxide, ferrous phosphate,
More preferred are ferric phosphate and the like. Although the synergistic effect of impregnating iron salts and malic acid is quite remarkable, the effect is poor when the amount of impregnation is small, and when the amount of impregnation is large, the adsorption ability of activated carbon for other substances is reduced, although not as much as malic acid. Therefore, the amount of iron salt impregnated is preferably 3 to 25% by weight.

To impregnate activated carbon with malic acid and iron salts, immerse the activated carbon in a mixed solution of malic acid and iron salts so that they are fully absorbed into the pores, and then dry in an oven or sprinkle these solutions thoroughly. The impregnated material may be dried. At this time, it is important to uniformly impregnate the malic acid and iron salt into the pores of the activated carbon, so it is necessary to dry at a slow speed. If the drying rate is too fast, the acid and iron salt that were once adsorbed inside the activated carbon may be desorbed and deposited on the surface of the activated carbon, resulting in a decrease in its performance. In addition, when the impregnated activated carbon is completely dry, its adsorption ability for ammonia and amines is greatly reduced, so it is necessary to use it in a state containing a small amount of water.

The air purifying agent of the present invention is prepared by mixing the activated carbon impregnated with aniline and the activated carbon impregnated with malic acid and iron salt as detailed above. The deodorizing agent prepared in this manner is effective in deodorizing living spaces such as offices and homes that mainly contain cigarette odors at a wide range of impregnating ratios and mixing ratios, and the mixing ratio is not particularly limited. Therefore, when each component has a preferable composition as described above, as shown in Examples 3 and 4, in order to increase the deodorization speed and suppress the amount of acetaldehyde re-released, the aniline-impregnated carbon is mixed with malic acid. It is preferable to mix in a larger amount of ferrous sulfate and ferrous sulfate than the impregnated carbon.

[Function] By mixing the beam of the present invention with activated carbon impregnated with golic acid and iron salt, the adsorption of ammonia, which is the weak point of activated carbon, can be improved, and lower aliphatic aldehydes, which are relatively abundant in cigarette odor, etc. can be improved. It is prepared by adding aniline-impregnated activated carbon to remove it.

The action of malic acid-impregnated activated carbon to adsorb ammonia is thought to be due to neutralization, and in the case of iron salts, it is thought to be due to complex formation, although the details are not clear.

When activated carbon is impregnated with equal amounts of malic acid or iron salt, malic acid shows higher ammonia adsorption ability, but
The adsorptivity of activated carbon for other substances is greatly reduced. When malic acid and iron salt are impregnated in the range described in claim 3, the ammonia adsorption property is the same as when malic acid or iron salt is impregnated alone. It reaches several times the calculated value. Therefore, since the required ammonia adsorption ability can be maintained even with a relatively small amount of mixed impregnation, there is an advantage that the adsorption ability of the base activated carbon to other substances is not inhibited.

Furthermore, the adsorption of ammonia by this mixed impregnated coal is particularly efficient at low concentrations, and even if the gas concentration fluctuates, it is difficult to re-release the adsorbed gas. This is considered to be because ammonia adsorption is based on a chemical reaction mechanism. The adsorption of amines other than ammonia is also high, and the mechanism is thought to be similar.

In addition, as an adsorbent for aldehydes due to apple oxygen deficiency, there are known adsorbents such as activated carbon impregnated with sulfite or acid sulfite, but the aniline-impregnated carbon used in the present invention is far more effective than these. has high adsorption ability for lower aliphatic aldehydes, especially in the low concentration region (aldehyde concentration 1100p).
p or less).

When aniline is impregnated, safety and health considerations are required, but the amount of impregnation as described in claim 2, which is preferred from the viewpoint of aldehyde adsorption properties, does not cause any bad odor. This is considered to be because the sweetfish 1fufu molecules are firmly adsorbed in the pores of the activated carbon. By the way, when a sample with an impregnated amount of 5.10.15°20.25.30% by weight was prepared and left in a closed container at room temperature (25°C), the odor was evaluated by a sensory test and F.
As a result of analysis using a high-sensitivity gas chromatograph equipped with a zation detector, no odor was detected in the sensory test, and no aniline was detected using the gas chromatograph.

In addition, the odor in the normal living environment: C is ammonia.

Hydrocarbons in addition to specific substances such as amines and aldehydes.

Although hydrogen sulfide and the like are present, the hydrocarbons are removed by the remaining physical adsorptive part of the activated carbon impregnated with malic acid, iron salt, aniline, etc., and hydrogen sulfide is removed by the catalytically active part. Physical effect of impregnated charcoal on hydrocarbons: It is particularly effective in removing odors in ordinary living environments such as offices and homes (・C).It also has a strong adsorption power for lower aliphatic aldehydes, so it can be used immediately after extinguishing a kerosene stove. It is also suitable for removing odors.Therefore, it is suitable for filters of air cleaning devices, etc.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but these Examples are not intended to limit the present invention in the same manner.

Example 1 A sample weighing 2 g on an anhydrous basis was placed in a glass bottle with a capacity of 3° and 97 d, and after degassing with a vacuum pump, a predetermined amount of ammonia water was added and vaporized.

Next, air was introduced to return the pressure to normal pressure, and the mixture was left in a constant temperature bath at 25°C, and the ammonia concentration was measured using a gas detection tube. The isothermal adsorption line was measured to determine the relationship between the amount of ammonia adsorbed and the gas concentration when equilibrium was reached.

Activated carbon (unimpregnated carbon), single impregnated carbon with malic acid and ferrous sulfate (20% by weight), mixed impregnated carbon (acid 14%, iron sulfate 6%), and aniline impregnated carbon (8% by weight) ), malic acid, ferrous sulfate mixed impregnated carbon (14% by weight of acid, 6% by weight of iron sulfate), and unimpregnated activated carbon in equal amounts. The results are shown in FIG.

Example 2 In the same manner as in Example 1, a sample was placed in a container and degassed, and a predetermined amount of acetaldehyde aqueous solution was added and vaporized. Next, air was introduced and left to stand, and the acetaldehyde concentration was measured with a gas detection tube, and the isothermal adsorption line when equilibrium was reached was measured. Activated carbon and its aniline-impregnated carbon (8% by weight), aniline-impregnated carbon (8% by weight), malic acid, ferrous sulfate mixed impregnated carbon (acid 14% by weight, iron sulfate 6%), unimpregnated activated carbon, etc. The measurement results for the mixture in portions are shown in FIG.

Example 3 Two lighted cigarettes (Seven Stars) are placed in an aluminum lm' box containing an air purifying device incorporating an air purifying agent, and the inside of the box is stirred with a fan to smoke the cigarettes. It burns and evenly disperses the smoke and odor inside.

After all the cigarettes had been burned, the gas was sampled, and the air purifier was then operated to examine the relationship between the operating time and the amount of residual odor, and evaluate the adsorption speed.

Odor sampling was performed using a Tetra Pak, and evaluation was performed using a three-point comparative odor bag method.

The total amount of air purifying agent used in the air purifying device was 300 g, and the air volume was 3 m''.

Activated carbon only, aniline-impregnated carbon (aniline 8% by weight) and malic acid/ferrous sulfate mixed impregnated carbon (acid 14 heavy engraving, sulfuric acid 6
% by weight) and a mixture of aniline-impregnated carbon and acid.
The results for a mixture of iron sulfate-impregnated carbon with a ratio of 3 near
As shown in the figure. As shown in FIG. 3, the greater the ratio of aniline-impregnated carbon, the faster the deodorization speed.

Example 4: Put 10 lighted cigarettes (Seven Stars) into an aluminum lm+ box with an air purifier containing an air purifier inside, and turn on the air purifier while allowing the cigarettes to naturally burn. It was operated to absorb smoke and odors. When the concentration of smoke and odor became almost constant, 10 more cigarettes were added and burned, and this process was repeated to adsorb the smoke and odor of a total of 50 cigarettes. After leaving this air purifier for one week, set it in an air purifier and use a clean aluminum one.
After placing it in a box and operating it for 10 minutes, the air inside the box was sampled with a syringe, and acetaldehyde was analyzed using a high-sensitivity gas chromatograph. This value is called the re-emission amount.

The total amount of air purifying agent used in the air purifying device was 300 g, and the air flow rate was 3 ln°.

Here, the air purifying agent aniline-impregnated carbon (8% by weight) and malic acid/ferrous sulfate mixed impregnated carbon (acid 14% by weight, iron sulfate 6%)
Figure 4 shows the results of measuring the amount of acetaldehyde released with different ratios. At the same time, a sensory evaluation was performed by smelling the smell inside the 1 m' box, and the results are shown in Table 1.

Table 1, Figure 4, and Table 1 show that when the amount of malic acid/ferrous sulfate mixed impregnated coal is higher, the amount of acetaldehyde released increases rapidly.
It is preferable to use more aniline-impregnated charcoal because it emits a unique sweet odor.

This is thought to be due to the weak adsorption power of acetaldehyde, which is physically adsorbed on the malic acid/ferrous sulfate impregnated carbon, and due to the displacement adsorption effect due to adsorption of other substances. When the ratio of malic acid/ferrous sulfate-impregnated carbon is small, the amount of acetaldehyde released is small, and low-boiling unsaturated hydrocarbons, which are weakly adsorbed on both activated carbons, are also released by displacement adsorption. This is probably because the smokiness of unsaturated hydrocarbons masks the sweetness of acetaldehyde.

[Brief explanation of the drawing]

FIG. 1 shows the isothermal adsorption line of ammonia gas at 25° C. and 60% relative humidity. 1. Activated carbon 2. Malic acid (20% by weight) impregnated with activated carbon. 3. Impregnating activated carbon with ferrous sulfate (20% by weight). 4. Activated carbon with malic acid (14% by weight) and ferrous sulfate (6% by weight)
weight%) attached. 5. Activated carbon and malic acid, ferrous sulfate mixed impregnated activated carbon (
144% by weight of acid, 6% by weight of iron sulfate). A mixture of equal parts of aniline impregnation activity (8% by weight). FIG. 2 shows the isothermal adsorption curve for acetaldehyde at 25° C. and 60% relative humidity. 1. Activated carbon 2. Activated carbon impregnated with aniline (8% by weight). 3. Activated carbon and malic acid, ferrous sulfate mixed impregnated activated carbon (
14% by weight of acid, 6% by weight of iron sulfate). A mixture of equal parts of aniline impregnation activity (8% by weight). Figure 3 shows the deodorization speed of tobacco odor at 25"C1 relative humidity of 60%. , 6% by weight of sulfuric acid
) in a ratio of 7:3. 13. Aniline-impregnated carbon: A mixture of acid and iron sulfate-impregnated carbon with a ratio of 3 near. Figure 4 shows the ratio of aniline impregnation to malic acid/ferrous sulfate mixed impregnated carbon and the amount of acetaldehyde re-released from an air purifier that has previously adsorbed the odor of 50 cigarettes at 25°C and 60% relative humidity. showed the relationship between Patent applicant: Matsushita Electric Industrial Co., Ltd., Kuraray Chemi Co., Ltd. Representative: Patent attorney: Hisao Koide,

Claims (4)

[Claims] (1) An air purifying agent made by mixing activated carbon impregnated with aniline, activated carbon impregnated with malic acid and iron salt. (2) The air purifying agent according to claim 1, wherein the amount of activated carbon impregnated with aniline is 3 to 30% by weight (based on activated carbon). (3) The impregnated amount of activated carbon impregnated with malic acid and iron salt is 5 to 30% by weight of malic acid (based on activated carbon) and 3 to 25% by weight of iron salt (based on activated carbon). air purifier. (4) The air purifying agent according to claim 1, wherein the activated carbon impregnated with aniline is mixed in a larger amount than the activated carbon impregnated with malic acid and iron salt.