JPH0810315A - Air cleaning agent and deodorizing filter using the same for air cleaner - Google Patents

Abstract

PURPOSE:To provide an air cleaning agent which has adsorbing and deodorizing effects widely to the respective bad smell components showing acidity to basic which bad smells such as a scent of tabacco, garbage smell and toilet smell contain and can be used for deodorizing the whole smell of living, and a deodorizing filter for an air cleaner using the above air cleaning agent. CONSTITUTION:An air cleaning agent contains alkali component, in which activated charcoal where a small cavity is developed and activated charcoal where a malic acid and an iron salt are impregnated are mixed. A deodorizing filter is formed by bearing the above air cleaning agent on a substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifying agent and a deodorizing filter for an air cleaner using the same, and more specifically, it has a deodorizing effect on all living odors such as cigarette odor, kitchen odor and toilet odor. Regarding what you have.

[0002]

2. Description of the Related Art Living odors to be deodorized are tobacco odors,
There are many kinds of odors such as kitchen garbage odor and toilet odor, and these odors are a mixture of various chemical substances. For example, tobacco odors are mainly composed of ammonia, acetaldehyde, isoprene, etc., garbage odors are mercaptans and amines, and toilet odors are mainly composed of ammonia, hydrogen sulfide, mercaptans, skatole, etc. In terms of physical properties, they are roughly classified into hydrogen sulfide, valeric acid and other acidic gases, ammonia, trimethylamine and other basic gases, isoprene and aldehydes and other neutral gases.

Activated carbon has been conventionally used for deodorizing these daily odors, but recently, for the purpose of removing a specific component, an impregnated activated carbon having a basic substance or an acidic substance attached to the surface of the activated carbon is also used. Has been done. Examples of this include an air purifying agent in which three kinds of activated carbons such as ordinary activated carbon, aniline-impregnated activated carbon, and malic acid-iron salt-impregnated activated carbon described in JP-B-3-41187 are disclosed. No. 388452-Japanese Patent Publication No. 4-38451.
Examples thereof include an air purifying agent obtained by mixing two types of activated carbons, aniline-impregnated activated carbon and phosphoric acid-aniline-impregnated activated carbon described in JP-A No. Further, JP-A-5-49922 describes an example in which fibrous activated carbon is impregnated like an air purifying agent in which activated carbon fibers are impregnated with aniline and an organic acid.

[0004]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 3-41187
Japanese Patent Publication No. 38452/1992 and Japanese Patent Publication No.
In Japanese Patent No. 38451, in order to remove ammonia and acetaldehyde, which are difficult to be adsorbed and removed by ordinary activated carbon, malic acid or phosphoric acid-iron salt-impregnated activated carbon, aniline-impregnated activated carbon are used or used in combination with activated carbon. Although it has a high adsorption capacity for acetaldehyde, its adsorption capacity for hydrocarbons such as benzene and hydrogen sulfide is lower than that of activated carbon alone. This indicates that the ability to adsorb hydrocarbons and hydrogen sulfide decreases due to the attachment of basic substances and acidic substances. Thus, it can be said that the adsorbing deodorant described in the publication has some effect in the case of a tobacco odor in which acetaldehyde and ammonia are considered to be the main components, but it is an object of the present invention, that is, a viewpoint of general life odor. Considering from the above, it does not have sufficient deodorizing effect on sulfur-containing compounds and amine compounds such as hydrogen sulfide and mercaptan which are components of food waste odor, and hydrogen sulfide, mercaptan and skatole which are components of toilet odor. Absent.

Even when fibrous activated carbon is used instead of granular activated carbon as described in JP-A-5-49922, the pores of activated carbon are filled with aniline or an organic acid so that the activated carbon is neutral. -The same result that the gas adsorption capacity for acidic components is reduced cannot be applied to all living odors.

On the other hand, when activated carbon is used as the adsorbent for the sulfur-containing compound, the adsorption of the activated carbon on the sulfur-containing compound is mainly physical adsorption in the pores of the activated carbon, and when the wind velocity passing through the activated carbon is slow. , Sulfur-containing compounds are adsorbed and removed because they can make sufficient contact with activated carbon, but when the wind speed is fast, small molecules such as hydrogen sulfide pass through the pores and are not adsorbed and removed sufficiently. . for that reason,
When deodorizing the air in a wide space, a large amount of air must be treated, and the wind velocity passing through the activated carbon was high, so that the removal of hydrogen sulfide was not sufficient. Further, in order to sufficiently adsorb and remove it, air has to be brought into contact with activated carbon at a slow speed, and a large amount of activated carbon has to be used, which causes a problem that the device becomes large.

Further, as a deodorizing method for removing a sulfur-containing compound such as hydrogen sulfide, there are a method using a neutralization reaction with activated carbon impregnated with an alkali component and a method using a desulfurization reaction with a metal oxide. However, with activated carbon impregnated with an alkaline component, the pores are filled by the impregnation, resulting in a decrease in the adsorption capacity for gas components other than the acidic gas. In addition, since metal oxides have no adsorptive ability and do not have a deodorizing effect on components other than sulfur-containing compounds, it is generally necessary to use activated carbon in combination when used as a deodorant.

[0008] As described above, when activated carbon impregnated with various substances is used to adsorb the individual substances of odorous components showing acidity to basicity, the substances effectively removed from the impregnated substances are However, the excellent adsorptive capacity originally possessed by activated carbon decreases, and if activated carbon is mixed to supplement this, the amount of impregnated activated carbon used is relatively reduced due to the incorporation of activated carbon. However, it becomes impossible to secure a sufficient adsorption amount.

Further, when the alkali-impregnated activated carbon that adsorbs and removes hydrogen sulfide and the organic acid-impregnated activated carbon that adsorbs and removes ammonia and the like are mixed and used, an alkali and an acid as impregnating components leak to the surface of the activated carbon. Cause a sum reaction,
Since the adsorption and removal capacity will be halved, it is usually not possible to use a mixture of alkali-impregnated activated carbon and organic acid-impregnated activated carbon as air purifiers.Assemble them separately as filters and combine these filters into one filter. Since it is used as an air purification filter, there are problems such as high ventilation resistance of the entire filter and increased manufacturing man-hours.

Therefore, the present invention overcomes the above-mentioned drawbacks,
An air purifying agent that has a wide adsorption and deodorizing effect on each odor component showing acidic to basicity that constitutes an odor such as cigarette odor, garbage odor, and toilet odor, and can be used for deodorizing all living odors. An object is to provide an improved deodorizing filter for an air cleaner.

[0011]

Means for Solving the Problems As a result of earnest studies on the adsorption capacity of activated carbon constituting an air purifying agent, the present inventor has found that by using activated carbon containing an alkaline component showing a specific alkalinity, It has been found that the acidic component can be efficiently adsorbed without reducing the adsorption amount for the basic component, and the present invention has been completed based on this finding.

The present invention comprises an air purifying agent in which activated carbon containing an alkaline component and having developed pores and activated carbon impregnated with malic acid and an iron salt are blended.

The above activated carbon exhibits alkalinity, especially p
Activated carbon showing H9 to 11 and activated carbon impregnated with malic acid and iron salt is an activated carbon showing acidity, particularly pH 1 to 3.

The activated carbon has a specific surface area of 1600.
It is m ² / g or more, the cumulative pore volume of the pore radius of 0.8 to 10 nm is 0.6 ml / g, and the benzene adsorption amount is 30% by weight or more.

The active carbon and the active carbon impregnated with malic acid and iron salt are contained in a weight ratio of 65 to 85:15 to 15:15.
It is an air purifier in the range of 35.

Further, the present invention comprises an air purifying agent containing activated carbon containing an alkali content and having fine pores, activated carbon impregnated with malic acid and iron salt, and activated carbon showing neutrality. .

The neutral activated carbon is an activated carbon having a pH of 5 to 8 and an adsorption amount of benzene of 30% by weight or more.

Further, the blending ratio of activated carbon containing an alkali component and having fine pores is 35% by weight or more, and the blending ratio of activated carbon impregnated with malic acid and iron salt is 15% by weight to
An air purifier mixed in the range of 35% by weight.

Further, the present invention comprises a deodorizing filter in which an air purifying agent according to claim 1 or 2 is carried on a substrate through which air can flow.

The substrate is made of a filter carrier having a hollow cell shape, or a foamed resin or a foamed metal.

Further, the carrying method comprises fixing the air purifying agent through the adhesive layer on the surface of the substrate.

The present invention will be described in detail below.

Regarding the deodorization of odors, it is known as the Weber-Hefner law that the strength of sensory odor decreases in proportion to the logarithm of the substance concentration in the case of a single gas, but in the case of a mixed odor, it is not always necessary. It doesn't always follow the rules. That is, the odor intensity may be increased or decreased due to the interaction of the gas components that form the mixed odor. Therefore, in the case of actually deodorizing, it is often not possible to obtain a sufficient effect by only removing a part of the gas constituting the odor, and in some cases,
On the contrary, the degree of odor may increase. Therefore, it must be a deodorant that can be widely adsorbed and removed for each component showing acidity to basicity of the odor component unless it completely removes the gas causing the odor.

The present invention comprises a specific activated carbon which is active in both acidic gas and neutral gas and which contains alkali and has fine pores, and malic acid and iron salt which are active in basic gas. It is characterized by comprising an air purifying agent mixed with activated carbon impregnated with and an air purifier deodorizing filter using the same.

The activated carbon containing an alkaline component and having developed pores used in the present invention shows a basicity of pH 9 or more in the pH measurement of the activated carbon test method according to JIS K1474, and the specific surface area according to the BET method. The measured value of nitrogen gas is 1600 m ² / g or more, and the pore radius is 0.8 to 10 n.
The cumulative pore volume of m is 0.6 ml in the steam absorption method.
/ G is activated carbon. Regarding the adsorption capacity of activated carbon, JIS is used as an index showing the adsorption capacity for hydrocarbons.
Activated carbon showing a value of 30% by weight or more as measured by the amount of benzene adsorbed by K1474. Such activated carbon can be manufactured by the following method.

As a manufacturing method, for example, 50 coconut shells are used.
Heat to 0-800 ℃, extinguish cooling, dry distillation carbonization,
Obtain a carbide. The obtained carbide is crushed and sized by repeating crushing and sieving in order to obtain a raw coal having a predetermined particle size. Next, the crushed and sized raw material coal has fine pores formed by the activation step. Activation is carried out using steam or carbon dioxide with a rotary kiln, etc., at 750 to 1050.
It is performed at a temperature of about ℃. By setting the activation time at this time longer than that in the case of producing general activated carbon, mesopores (pore diameter 1 to 25 nm) and micropores (pore diameter 0.4 to 1 n).
m), activated carbon in which fine pores such as submicropores (pore diameter 0.4 nm or less) are developed can be obtained.

The activated carbon thus obtained has some ash content such as alkali metal or alkaline earth derived from the raw material of the activated carbon such as coconut shell. In the usual production of activated carbon, these ash components are washed and removed with acid and water to produce products. As a result, the pH of these activated carbons is 5-8 neutral. On the other hand, the activated carbon used in the present invention is used as it is without washing and removing these ash components. The remaining ash, which is an alkali, exists in the pores of the activated carbon and reacts with a sulfur-containing compound or an acidic substance to be used for adsorption removal. The p of activated carbon containing alkali thus obtained was
H has a basicity of 9 or more, usually 9 to 11, and the adsorption amount for hydrogen sulfide has a value of 35% by weight or more. Further, as compared with normal activated carbon, the activation operation was carried out for a long time, and the pores were developed to increase both the pore volume and the specific surface area.
The specific surface area is 1600 m ² while the value measured by the BET method is 1000 m ² / g or more for ordinary activated carbon.
/ G or more, and the cumulative pore volume at a pore radius of 0.8 to 10 nm is 0.
It shows a value of 0.6 ml / g, whereas the adsorption amount of benzene is 30% by weight or more, and particularly 40% by weight or more, which is the same as that of ordinary activated carbon. .

As described above, the alkali-containing activated carbon used in the present invention has a different manufacturing process from that of ordinary activated carbon, and from the viewpoint of deodorizing performance, the chemical neutralization reactivity to acidic gas and the physical properties of activated carbon are the same. It also has a specific adsorptive capacity, which is essentially different from ordinary activated carbon having only a physical adsorptive capacity. Further, the pH of the obtained activated carbon shows a basicity of pH 9 or more, and shows a value different from the pH values of 5 to 8 which are shown by ordinary activated carbon. This difference in pH can be easily confirmed by discoloring the pH test paper, for example, by bringing the activated carbon into contact with the pH test paper moistened with water.

On the other hand, in the case of impregnated activated carbon in which ordinary activated carbon is supported by impregnating it with an alkali component, the pores of activated carbon are filled with alkaline components, and the physical adsorption inherent to activated carbon is poor. Therefore, these impregnated activated carbons and the activated carbon containing an alkali component used this time are greatly different in that they have developed pores and are excellent in physical adsorption.

In order to obtain the alkali-containing activated carbon used in the present invention, the alkali content existing in the raw material such as coconut shell, wood and coal is used, and the raw material is an alkali metal or alkaline earth metal compound. It can be produced by carrying out dry distillation carbonization after impregnating an alkali content with the above treatment and sufficiently activating. It can also be produced by chemical activation using a hydroxide, carbonate or sulfide of an alkali metal or alkaline earth metal compound. further,
It can also be produced by impregnating normal activated carbon with an alkali and then increasing the specific surface area of the activated carbon by steam activation or the like to recover the adsorption capacity for benzene reduced by the impregnation to the same level as or higher than that of ordinary activated carbon.

The activated carbon used in the present invention can be produced not only by using palm shells but also by using plant-based carbon materials such as wood and charcoal and mineral-based carbon materials such as coal. Further, as the shape of the activated carbon, any of crushed activated carbon, granular activated carbon such as granulated activated carbon, and powdered activated carbon can be used.

The activated carbon impregnated with malic acid and iron salt used in the present invention is normal activated carbon having neutrality impregnated with malic acid and iron salt.
Is generally 1-3. Malic acid impregnation amount is generally 5 to 3
The iron salt is, for example, ferrous sulfate,
Ferric sulfate, ferrous chloride, ferric chloride, ferrous phosphate,
Ferric phosphate or the like is used, and the impregnated amount thereof is used in the range of 3 to 25% by weight.

The impregnated activated carbon can be produced by immersing the activated carbon in a mixed solution of malic acid and an iron salt, allowing the activated carbon to sufficiently adsorb into the pores, and then filtering and drying. The obtained impregnated activated carbon exhibits an acidic value of pH 1 to 3, and the adsorption amount of ammonia is 7% by weight or more.

The neutral activated carbon used in the present invention is an ordinary activated carbon generally used as activated carbon. For example, coconut shell as a raw material is carbonized by carbonization, and activated carbon such as steam is used to convert the activated carbon into hydrochloric acid. It was washed with water and water to remove ash from the raw materials such as coconut shells. Such activated carbon has a pH of 5 to 8 and has developed pores, and the benzene adsorption capacity (test method according to JIS K1474) as an index showing the adsorption capacity for hydrocarbons shows a value of 30% by weight or more. It is a thing.

The air purifying agent of the present invention is a mixture of the above-mentioned two types of activated carbon, that is, activated carbon containing alkali and having fine pores, and activated carbon impregnated with malic acid and iron salt.
Alternatively, it is prepared by mixing three types of activated carbon containing an alkaline component and having fine pores, activated carbon impregnated with malic acid and iron salt, and activated carbon showing neutrality. The activated carbon used is powdered activated carbon having a particle size of 150 μm or less, 15
Granular activated carbon with a particle size of 0 μm or more can also be used, and what kind of particle size range of activated carbon is to be used, when the air purifying agent is applied to the purifying device, for example, whether it is a filter or a cartridge. It is determined depending on the required adsorption amount, pressure loss during purification operation, and the like. When this air purifying agent is used as a deodorizing filter using a roll core as a base material, 20
Use of particles having a particle size of ˜42 mesh gives favorable results in terms of filter performance and handling.

The activated carbon containing an alkali component and having fine pores is chemically neutralized by adsorbing a sulfur-containing compound such as hydrogen sulfide or an acidic gas by the alkali component present in the pores of the activated carbon. To remove. Further, it has a function of physically adsorbing and removing a nonpolar gas such as hydrocarbon by the pores developed by activation. Activated carbon impregnated with malic acid and an iron salt has a high adsorption ability for alkaline gases such as ammonia and trimethylamine, and has an action of removing. The activated carbon exhibiting neutrality is an ordinary activated carbon which adsorbs various gas components in a wide range and has a high adsorption ability especially for a neutral gas, and these can be adsorbed and removed.

When these activated carbons are blended as an air purifying agent, the blending ratio should be changed in a timely manner depending on the type of the constituent components of the odorous gas for deodorization so that it is blended so as to be compatible with the odorous gas. When targeting food waste odors, toilet odors, etc., the deodorizing effect will be excellent if the following proportions are used in consideration of the removal rate of these odor components and the degree of tobacco odor reduction. be able to.

That is, when an activated carbon containing an alkaline component and having developed pores and an activated carbon impregnated with malic acid and an iron salt are blended, it is expressed in% by weight and is 65 to 85: 1.
The range of 5 to 35 is preferable, and particularly when used in the range of 75 to 85:15 to 25, a preferable air purifying agent having a high degree of reduction against tobacco odor can be obtained.

In addition, a mixture of activated carbon showing neutrality is added.
When mixing different types of activated carbon, activated carbon containing alkali and well-developed pores and activated carbon showing neutrality have low ability to adsorb ammonia. It is necessary to add 15% by weight or more of activated carbon impregnated with salt, and the upper limit must be 35% by weight or less, preferably 25% by weight or less in consideration of adsorption of other components such as neutral gas. Therefore, the total amount of activated carbon containing an alkali component and having fine pores and activated carbon showing neutrality is 65% by weight or more and 85% by weight or less,
It is preferably regulated to 75% by weight or more and 85% by weight or less. Among them, the activated carbon containing an alkali content and having developed pores needs to be 35% by weight or more in consideration of the adsorption amount of hydrogen sulfide and mercaptans, and the remaining portion is blended with activated carbon showing neutrality. be able to. The mixing ratio of these is determined by the components of the target odorous gas and the like. Therefore, as the blending range, the blending ratio of the activated carbon containing an alkali component and having fine pores, the activated carbon showing neutrality, and the activated carbon impregnated with malic acid and iron salt is 35 to 35% by weight.
Used in the range of 75:10 to 50:15 to 35, especially 3
When used in the range of 5 to 55:25 to 45:15 to 25, an air purifying agent having a deodorizing effect on all living odors can be obtained.

Next, a deodorizing filter for an air cleaner using the air purifying agent of the present invention will be described.

The substrate used as a filter may be a roll core carrier having a circular cell shape, a hexagonal honeycomb carrier, a corrugated corrugated carrier having a hollow cell shape, which is widely used as a filter carrier or a catalyst carrier. The material of the substrate is paper, resin-impregnated paper, plastics such as vinyl chloride, ceramic or ceramic paper, and metal such as aluminum.

Further, as the filter substrate, foamed resins such as urethane foam and styrene foam, foamed metals such as foamed aluminum, titanium foam, iron foam and the like having continuous pores through which air can flow. For example, the same can be used, and the filter can be formed by using a fibrous substrate such as glass fiber, synthetic fiber or natural fiber.

The deodorizing filter is produced by supporting the air purifying agent of the present invention on the above filter substrate. For carrying, the filter substrate is dipped in a pressure-sensitive adhesive liquid consisting of an acrylic emulsion, impregnated and coated with the acrylic emulsion, dried at about 60 ° C. for 1 hour to sufficiently remove water or solvent, and then an air purifying agent is added to the acrylic emulsion. Adhere via. Further, as the pressure-sensitive adhesive to be used, a rubber-based, vinyl ether-based or silicone-based pressure-sensitive adhesive can be used, and it can also be prepared by spray-coating the filter substrate with the pressure-sensitive adhesive.

The deodorizing filter thus obtained is used by being attached to an air purifier or the like.

Next, the present invention will be described in more detail by way of experimental examples and examples.

[0046]

【Example】

Experimental Example 1 Activated carbon (hereinafter, referred to as alkali-containing activated carbon) containing an alkali content produced by carbonizing coconut shells by carbonization and activated with steam (hereinafter, referred to as alkali-containing activated carbon) and activated carbon showing neutrality (hereinafter, referred to as
The difference in adsorption activity between neutral activated carbon) and alkali-impregnated activated carbon (hereinafter referred to as alkali-impregnated activated carbon) was examined.

For examination, alkali-containing activated carbon (pH: 1
1.0, hydrogen sulfide adsorption amount: 38.0%, benzene adsorption amount: 47.1%), neutral activated carbon (pH: 5.8, benzene adsorption amount: 34.8%), and alkali-impregnated activated carbon. And the particle size was in the range of 20 to 42 mesh.

Then, the cell diameter is 8.5 mm, 358 mm ×
A roll core made of urea resin-impregnated paper having a thickness of 58 mm and a thickness of 10 mm was dipped in an acrylic emulsion-based pressure-sensitive adhesive, the pressure-sensitive adhesive was applied, dried at 60 ° C. for 1 hour to remove water, and then each activated carbon was supported.

The pressure loss of the produced filter was 2 m in wind speed.
It was a very low value of 0.8 mmH ₂ O / sec. This filter was attached to a deodorizing tester having a fan motor and installed in a 4 m ³ chamber. A standard gas was introduced into the chamber to adjust the gas concentration in the chamber to 20 ppm. The test machine was operated at a wind speed of 1.0 or 2.2 m / sec, the gas concentration in the chamber at each time was measured, and the residual rate with respect to the initial concentration was determined. The results are shown in FIG. 1, in which a
Indicates hydrogen sulfide, b indicates methyl mercaptan, c indicates isoprene, and d indicates the gas residual rate in the case of styrene. The concentration of each gas was measured by a gas chromatograph.

Experimental Example 2 In order to compare the activity of alkali-containing activated carbon with neutral activated carbon and alkali-impregnated activated carbon, these activated carbons were used as activated carbon impregnated with malic acid and iron salt (hereinafter referred to as iron malate-impregnated activated carbon). An examination was carried out in a system in which activated carbon impregnated with aniline (hereinafter referred to as activated carbon impregnated with aniline) was mixed.

According to the invention described in Japanese Examined Patent Publication No. 3-41187, neutral activated carbon, iron malate-impregnated activated carbon and aniline-impregnated activated carbon were mixed at a weight ratio of 35:48:17 to obtain sample 1.

Instead of the neutral activated carbon used in Sample 1, alkali-containing activated carbon (pH: 11.0, hydrogen sulfide adsorption amount: 38.0%, benzene adsorption amount: 47.1%) was used in the same mixing ratio. Sample 2 prepared by mixing and mixing, and sample 3 prepared by mixing alkali-impregnated activated carbon were prepared.

Then, a filter was prepared in the same manner as in Experimental Example 1 and a deodorizing test was conducted to determine the gas residual rate.
The pressure loss of the obtained filter was 2 m / se for the wind speed.
In c, it was 0.8 mmH ₂ O, and the gas concentration was measured using a gas chromatograph or a gas detector tube. The results are shown in FIGS. 2 and 3. In FIG. 2, a is isoprene and b
Shows acetaldehyde, c shows ammonia, d shows trimethylamine, and in FIG. 3, e shows hydrogen sulfide and f shows the gas residual rate in the case of methyl mercaptan.

Examples 1-3 and Comparative Examples 1-2 Alkali-containing activated carbon (p
H: 11.0, hydrogen sulfide adsorption: 38.0%, benzene adsorption: 47.1%) and neutral activated carbon (pH: 5.
8, benzene adsorption amount: 34.8%) and iron malate salt-impregnated activated carbon (impregnation amount: 27%, pH: 1.6, ammonia adsorption amount: 8.1%) in a weight ratio of 8: 0: 20. (Example 1), 50:30:20 (Example 2) and 40:
40:20 (Example 3) was mixed to prepare an air purifying agent, and a filter was produced in the same manner as in Experimental Example 1.
For comparison, a filter was prepared using only neutral activated carbon (pH: 5.8, benzene adsorption amount: 34.8%) (Comparative Example 1), and further neutral activated carbon (pH: 5.8). , Benzene adsorption amount: 34.8%) and ferric malate-impregnated activated carbon (impregnation amount: 27%, pH: 1.6, ammonia adsorption amount:
8.1%) and aniline-impregnated activated carbon (impregnation amount: 8%,
(pH: 10.5, acetaldehyde adsorption: 4.7%)
And were mixed at a weight ratio of 35:48:17 to prepare a filter (Comparative Example 2). The pressure loss of the obtained filter was 0.8 mmH ₂ O at a wind speed of 2 m / sec.

The obtained filter is 50 mm × 50 m
It was mounted on a deodorizing tester having a cutting fan motor having a size of m and a thickness of 10 mm, and installed in a chamber of 1 m ³ . A standard gas was introduced into the chamber to adjust the gas concentration to 20 ppm. The gas concentration was measured by a gas chromatograph or a gas detector tube. The deodorization test was performed at a wind speed of 2.3 m / sec, and the gas removal rate with respect to the initial gas concentration was determined from the gas concentration after 1 hour.
The results are shown in Table 1.

[0056]

[Table 1] Next, regarding the filters produced in Examples 1 to 3,
The deodorizing effect on tobacco odor was examined using the following evaluation method.

The obtained filter is 50 mm × 50 m
It was mounted on a deodorizing tester having a cutting fan motor having a size of m and a thickness of 10 mm, and installed in a chamber of 1 m ³ . Cigarette (mild seven) in the chamber
Burning 5 pieces, operating the deodorizing tester for 1 hour at a wind speed of 2.3 m / sec, collecting the gas in the chamber before and after the test and performing a sensory test for odors based on the 6-level odor intensity display method by the Environmental Agency. It was Further, the concentration of isoprene, ammonia and acetaldehyde, which are considered to be closely related to cigarette odor, was measured by a gas chromatograph or a gas detector tube to obtain the removal rate.

For comparison, alkali-containing activated carbon (pH: 11.0, hydrogen sulfide adsorption amount: 38.0%, benzene adsorption amount: 47.1%) and iron malate iron-impregnated activated carbon (impregnation amount: 27) %, PH: 1.6, ammonia adsorption amount:
8.1%) and aniline-impregnated activated carbon (impregnation amount: 8%,
(pH: 10.5, acetaldehyde adsorption: 4.7%)
And 55 by weight, 55:15:30 (Comparative Example 3), 60:
Table 2 shows the results of evaluation by mixing the filters in the ratios of 0:40 (Comparative Example 4) and 0:10:90 (Comparative Example 5) to prepare a filter.

[0059]

[Table 2] FIG. 4 shows the correlation between isoprene, ammonia, and acetaldehyde removal rates of these gases and the degree of reduction in tobacco odor intensity by a sensory test.

Examples 4 to 9 and Comparative Examples 6 to 9 Filters having various blending ratios were prepared in the same manner as in Examples 1 to 3, and the evaluation results are shown in Table 3 together with the blending ratios. Since the comprehensive evaluation in Table 3 aims at the deodorizing effect on the overall living odor, the degree of reduction of the tobacco odor intensity exceeds -1.1 points in consideration of the deodorizing effect of the tobacco odor, and
When the removal rates of hydrogen sulfide, methyl mercaptan, and trimethylamine caused by the smell of garbage and toilet were 60% or more, all were evaluated as ◯, and the other cases were evaluated as x.

[0061]

[Table 3] Experimental Example 3 The filter of Example 1 was cut into a size of 125 mm × 125 mm and a thickness of 10 mm, placed in a chamber of 4 m ³ , and the gas initial concentration was set to 0.7 ppm of hydrogen sulfide and 3 ppm of methyl mercaptan, and a wind speed of 2.5 m / In the condition of sec,
The residual rate of the gas was examined under the conditions of 20 ° C. and relative humidity of 80% RH and 50% RH. Results are shown in FIG. In the figure, a represents the gas residual ratio in the case of hydrogen sulfide and b represents the gas residual ratio in the case of methyl mercaptan.

According to FIG. 1, the alkali-containing activated carbon exhibits an equivalent adsorption capacity for hydrogen sulfide and a higher adsorption capacity for methyl mercaptan as compared with the alkali-impregnated activated carbon. Further, even when compared with the neutral activated carbon, it shows the same adsorption capacity for isoprene and high adsorption capacity for styrene. This is because the alkali content in the alkali-containing activated carbon shows adsorptivity for sulfur-containing compounds as well as the alkali content of the alkali-impregnated activated carbon, and as a result of the development of pores, the physical adsorption capacity is higher than that of the alkali-impregnated activated carbon. It is shown to be larger than that of neutral activated carbon.

FIGS. 2 and 3 show that the sample 2 containing the activated carbon containing alkali has a higher adsorption capacity for isoprene, acetaldehyde and trimethylamine than the sample 3 containing activated carbon impregnated with alkali, and the activated carbon of neutral Compared with the compounded sample 1, it shows a high adsorption capacity for hydrogen sulfide and methyl mercaptan.

As described above, the alkali-containing activated carbon has a physical adsorption to neutral gas such as isoprene and styrene which is equal to or higher than that of the neutral activated carbon, and is superior to the alkali-impregnated activated carbon to the adsorption of the sulfur-containing compound. I understand.

Further, as shown in c and d of FIG. 2, even when alkali-containing activated carbon is blended, the adsorption capacity of ammonia and trimethylamine shown by iron malate iron-impregnated activated carbon is when neutral activated carbon is blended. It is maintained at the same level as. However, when the alkali-impregnated activated carbon is blended, the adsorbed amount decreases with respect to trimethylamine having a large molecule, especially when the wind speed increases. This indicates that the malic acid and alkali used for the impregnation were consumed by the neutralization reaction on the surface of the activated carbon and in the relatively large pores, and could not contribute to the neutralization and adsorption of triethylamine. When adsorbing small molecules such as ammonia at a low wind speed, ammonia diffuses into the fine pores, and malic acid in the fine pores preferentially remains in the unreacted portion. As a result of being neutralized and adsorbed by, it is considered that the effect is small. In the case of the alkali-containing activated carbon used in the present invention, since the contained alkali content is strongly bonded to carbon inside the pores, unlike the impregnated alkali, it is likely to neutralize malic acid. Nonetheless, it is understood that the mixed use of iron malate does not impair the ability of the activated carbon impregnated with iron malate to adsorb amines.

Therefore, it is not necessary to separately prepare filters with activated carbon impregnated with acid and alkali and combine them into one filter, but it is possible to prepare filters using an air purifying agent mixed with activated carbon containing alkali. it can.

From the results shown in Table 1, the filter of the present invention shows a removal rate of 60% or more for each gas and has adsorption activity for various gases, but only the neutral activated carbon (comparison In Example 1), the adsorptivity for basic substances is poor, and in Comparative Example 2, since alkali-containing activated carbon is not included, the adsorptivity for sulfur-containing compounds is poor and the adsorptivity for isoprene, which is a neutral gas, is low. I understand.

It can be seen from Table 2 and FIG. 4 that the filters of Examples 1 to 3 have improved tobacco odor. Further, the degree of reduction in tobacco odor intensity and the removal rates of isoprene and ammonia show a positive correlation, and both are considered to have some role in the removal of tobacco odor. When neutral activated carbon is used, the removal rate of isoprene is high, but it is extremely low for ammonia, so that it is not so effective for tobacco odor. Further, a negative correlation is shown for acetaldehyde, indicating that tobacco odor is difficult to reduce only by increasing the removal rate of acetaldehyde. Therefore, it can be seen that an air purifying agent having a sufficient deodorizing effect on tobacco odor can be obtained without the combined use of aniline-impregnated activated carbon showing high activity for removing acetaldehyde.

According to Table 3, the compositions of Examples 4, 7 and 8 had an ammonia removal rate of 55%, but had an excellent deodorizing effect on the removal of tobacco odor, and the deodorization of all living odors. It turns out that it is useful as a filter.

Further, from the results of Table 3, regarding the blending ratio of activated carbon, in order to remove basic gases such as ammonia and trimethylamine, it was found that 15% iron malate salt-impregnated activated carbon was used.
It can be seen that the amount of the activated carbon containing alkali is required to be 35% by weight or more, and that the activated carbon containing alkali is required to remove 35% by weight or more of the sulfur-containing compounds such as hydrogen sulfide and methyl mercaptan. Also,
When the iron malate salt-impregnated activated carbon exceeds 35% by weight and the alkali-containing activated carbon is less than 65% by weight, the removal rate for neutral gases such as isoprene tends to decrease. Therefore, the alkali-containing activated carbon is used in the range of 35 to 85% by weight, and the remaining portion containing 35% by weight or more of the alkali-containing activated carbon is mixed with the alkali-containing activated carbon to neutral gas in the range of 50% by weight or less. It can be replaced by neutral activated carbon with similar adsorption activity. Neutral activated carbon shows a wide adsorption activity for various gases other than the studied gases, and therefore it is considered that the deodorizing effect for all living odors will be improved by blending it.

According to FIG. 5, the influence of humidity on the removal of hydrogen sulfide and methyl mercaptan is not recognized. This means that in the case of ordinary neutral activated carbon, in a high humidity environment with a relative humidity of 60% RH or more, the adsorption of water precedes the adsorption of gas and the gas adsorption capacity tends to decrease. It is considered that the contained activated carbon is not affected by humidity at all because it is chemically adsorbed and removed by neutralization with alkali. That is, it is possible to obtain a deodorizing filter for an air cleaner that does not deteriorate in deodorizing ability even in a humid place such as a toilet or kitchen.

[0072]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain an air purifying agent and a deodorizing filter having an effect on all living odors. Also, even if the alkali-containing activated carbon is mixed with the impregnated activated carbon, the adsorption activity of the impregnated activated carbon does not decrease,
Since an air purifying agent can be prepared by mixing these activated carbons and can be produced as a single filter from the beginning, a low-pressure loss filter can be obtained, and a deodorizing filter improved in terms of the number of manufacturing steps can be obtained.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between a gas residual ratio and time of alkali-containing activated carbon and alkali-impregnated activated carbon or neutral activated carbon.

FIG. 2 is a graph showing a relationship between a gas residual rate and time of an air cleaning agent containing alkali-containing activated carbon and an air cleaning agent containing alkali-impregnated activated carbon or neutral activated carbon.

FIG. 3 is a graph showing a relationship between a gas residual rate and time of an air purifying agent containing alkali-containing activated carbon and an air purifying agent containing alkali-impregnated activated carbon or neutral activated carbon.

FIG. 4 is a graph showing the correlation between the degree of reduction in tobacco odor intensity and the gas removal rate.

FIG. 5 is a graph showing the influence of humidity on the residual gas ratio of the air purifying agent of the present invention.

Claims (3)

[Claims] 1. An air purifying agent containing activated carbon containing an alkaline component and having fine pores, and activated carbon impregnated with malic acid and an iron salt. 2. An air purification agent containing activated carbon containing an alkaline component and having fine pores, activated carbon impregnated with malic acid and an iron salt, and activated carbon showing neutrality. 3. A deodorizing filter in which an air purifying agent according to claim 1 is carried on a substrate through which air can flow.