JPH07204259A - Air cleaning agent containing metal carboxylic acid salt - Google Patents

Abstract

PURPOSE:To eliminate a very small amount of odorous components existing in daily living space by mixing a porous material having metal carboxylic acid salt added and activated carbon to form an air cleaning agent. CONSTITUTION:For assembling an air cleaning filter, a honeycomb base material 2 and nonwoven fabric 4 are bonded only at one side with a hot press or the like, using a spider web-like bonding sheet 5. Then, an air cleaning agent 3 is evenly sprayed to the assembled body from upper level. Also, another spider web-like bonding sheet 5 is placed thereon and heated. In this case, the air cleaning agent 3 is formed by mixing a porous material with at least one kind of metal carboxylic acid salt added and activated carbon. Also, the porous material is activated carbon and such a porous material as having at least one type of metal carboxylic acid salt added is formed by adding 0.5 to 30 pts.wt. of metal carboxylic acid salt to 100 pts.wt. of the porous material. This agent 3 is excellent in adsorbing and removing lower aliphatic aldehyde, particularly acetaldehyde contained in cigarette smoke or the like in the air forming one of causes for odor.

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 an air purifying device. More specifically, it is excellent in adsorbing low-concentration aliphatic aldehydes in the gas phase and adsorbing other malodorous components. It is a high adsorbent and air purifier, and is suitable for purifying indoor air in offices and homes.

[0002]

2. Description of the Related Art In recent years, trace amounts of hydrogen sulfide, ammonia, mercaptan, which are present in living spaces due to changes in living environment,
There is increasing interest in removing malodorous gases such as metal ions and aldehydes. In order to remove these malodorous gases and maintain a comfortable living environment, a deodorant is required, and various malodorous gas adsorbents are also used in home life.

Since these malodorous gas adsorbents are used in daily life, they are required to satisfy the following conditions.

(1) It has an excellent deodorizing performance against various malodorous gases such as a slight amount of hydrogen sulfide, ammonia, mercaptan, metal ions and aldehydes existing in daily living space. (2) High safety. (3) It should be easy to handle. (4) It should be inexpensive.

There are many types of malodorous components contained in the air of ordinary living spaces such as indoors or in cars, but one of the most significant causes is aldehydes contained in a large amount in cigarette smoke, Especially the odor of acetaldehyde.

On the other hand, generally, activated carbon is often used as an air purifying agent. Activated carbon is a unique material that has extremely excellent adsorptivity as a non-polar adsorbent, and exhibits high adsorptivity for almost all gaseous substances. However, it is difficult for ordinary activated carbon to sufficiently remove lower aliphatic aldehydes, ammonia, and lower metal ions in the above malodor.

As a method of solving this drawback, an adsorbent in which aniline is impregnated on activated carbon is disclosed in Japanese Patent Publication No. 60-54065, and one in which 1 to 30 parts of aniline is impregnated on 100 parts of activated carbon is It is described as being effective in adsorbing lower aliphatic aldehydes such as acetaldehyde.

Further, an attempt to impregnate an activated carbon with an ammonium salt, a sulfite or an acidic sulfite has been proposed.
(JP-A-53-29292). However, the effect is not sufficiently satisfactory, and often becomes a problem particularly in the case of air purification of living space. The effect is extremely insufficient especially for odors in the low concentration region.

A product obtained by adding ascorbic acid to iron sulfate is also commercially available. This type of deodorant has a good deodorizing effect on basic malodorous gases such as ammonia and metal ions, but has almost no deodorizing effect on hydrogen sulfide, mercaptans, aldehydes, etc., and dissolves when wet with water. It has a drawback that it cannot be used for deodorizing gas.

Many other chemical deodorants have been disclosed, but many have strong acidity and alkalinity, and the types of gases that can be removed are limited, and some have the drawback that they are easily affected by moisture absorption or drying. Many.

Bentonite to which an inorganic polybasic acid is attached JP-A-60-43373, JP-A-61-164556, which uses a catalytic action of vitamin B12, JP-A-62-164556 There are other organic deodorants, such as 131514, but they have low heat resistance, are difficult to process, and are expensive.

[0012] By mixing the above various porous materials, activated carbon, etc., the malodor in the living space can be almost removed. However, among the conventional activated carbons,
The activated carbon impregnated with aniline has a problem that the aniline is desorbed. Aniline is an extremely harmful substance designated as a poisonous substance, and there were many problems in its use for household use.

[0013]

DISCLOSURE OF THE INVENTION The present invention is intended to remove a small amount of malodorous components present in daily living space, and has an excellent deodorizing effect on malodorous aldehydes which are particularly problematic. Further, the present invention intends to provide an air purifier having a new composition, which has a high deodorizing effect on malodorous components other than aldehydes, is highly safe and is easy to handle, and has a long-life malodorous gas decomposing property. .

[0014]

Means for Solving the Problems The present inventors have noted that aniline-impregnated activated carbon has poor durability. Since the activated carbon has a weak ability to adsorb and hold aniline, it has been found that even if a large amount of it is impregnated, it is desorbed by the addition of heat or the like, and as a result, the adsorption power of the lower aliphatic aldehyde decreases.
Therefore, in order to obtain an air purifying agent that retains sufficient adsorption power for lower aliphatic aldehydes and has excellent durability, and that can also remove other malodorous components, we examined adsorbents of various compositions. did.

As a result, by admixing the porous material impregnated with the metal carboxylate excellent in the adsorptivity of the lower aliphatic aldehyde and the activated carbon, the excellent adsorptivity to the malodorous components other than the lower aliphatic aldehyde is obtained. Based on this, it was found that an adsorbent having a

That is, the present invention relates to an air purifying agent obtained by impregnating a porous material with at least one metal carboxylate, and an air purifying apparatus using the same. Here, it is more preferable that the porous material is activated carbon. Further, it is more preferable that the amount of the metal carboxylate to be impregnated is 0.5 to 30 parts with respect to 100 parts of the porous substance.

The present invention will be described in detail below.

The air purifying agent of the present invention must have a composition in which a porous substance impregnated with at least one metal carboxylate and activated carbon are mixed.

The term "porous material" as used herein means that the surface of an ordinary porous material is often composed of micropores or cracks, but not only the surface of these materials that can be observed from the outside, but also the internal micropores or crack surfaces. Is also meant to include. In the present invention, these medium metal carboxylates can be widely used as long as they are materials that do not deteriorate and have a large specific surface area and high adsorptivity as described above. Examples thereof include activated carbon, zeolite, activated alumina, silica gel, zirconia, titanium oxide and the like.

The activated carbon used as a carrier for the metal carboxylate here has a large specific surface area of several hundred m ² or more per 1 g, and can be widely used as long as it is a carbon material exhibiting high adsorptivity. . As the raw material of the activated carbon, a charcoal such as coconut shell or wood or coal is usually used, but any may be used. The activation method may also be a method obtained by activation at a high temperature with steam or carbon dioxide, or a method of treatment with a chemical such as zinc chloride, phosphoric acid, concentrated sulfuric acid or the like.

The shape of the activated carbon can be any of crushed coal, granulated coal and granulated coal, but a sheet-shaped adsorption layer impregnated with the granulated carbon or activated carbon is convenient for handling such as pressure loss and replacement. Granulated coal is added to 100 parts of carbon material according to the conventional method.
It is prepared by adding 60 parts of petroleum pitch or coal tar as a binder, mixing and molding, and then activating.

The zeolite used in the present invention is an aluminosilicate, which is a substance having a three-dimensional skeleton and a pore structure formed in the voids. It has a large specific surface area of more than 500 m ² / g and high adsorptivity based on it. Its composition,
The structure is not particularly limited, and both natural products and synthetic products can be used. The pore volume, particle size, and shape are not particularly limited, but the pore volume is 0.3 ml / g or more and the particle size is 50 mesh or less (particle size of about 0.
3 mm or more) is preferable.

The activated alumina used in the present invention is mainly composed of alumina oxide, has a porous structure, and exhibits a high adsorptivity. The pore volume, particle size, and shape are not particularly limited, but the pore volume is 0.3 ml / g or more and the particle size is 50 mesh or less (particle size is about
0.3 mm or more) is preferable.

The silica gel used in the present invention is an adsorbent produced by coagulating a silicic acid colloidal solution. The main component is silicon dioxide, which has a pore structure, has a specific surface area of 90 to 500 m ² / g, and exhibits high adsorptivity. The pore volume, particle size, and shape are not particularly limited, but the pore volume is 0.3 ml / g or more and the particle size is 50 mesh or less (particle diameter of about 0.3 mm or more) due to the relationship between the adsorption amount of metal carboxylate and pressure loss. ) Is preferred.

The zirconia used in the present invention is usually zirconium oxide obtained by heating zirconium hydroxide. During the sintering process of the powder, when transitioning from a monoclinic system to an orthorhombic system at 900 ° C, a few percent of the volume shrinks to form a porous material having a specific surface area of 100 to 200 m ² / g. Zirconia sinter is used as a carrier because it has adsorptivity and has extremely high chemical stability. The properties of titanium oxide are almost the same.

Among these porous materials, activated carbon has a large specific surface area and thus a large metal carboxylate carrying capacity, and since the surface is non-polar, there is no possibility of reacting with the carboxylate and causing a chemical change. Further, it is most preferable as a carrier for the metal carboxylate, since it has a high adsorbability of a malodorous substance in the gas phase and thus has a high deodorizing rate of a malodor, and the deodorizing rate is less likely to decrease even after long-term use.

The shape of these porous substances is not particularly limited. For example, in addition to granular or powdery form, fibrous, honeycomb, sheet-like, cloth-like, felt-like, or powdery porous substance is used as urethane foam or the like. It is possible to use, for example, those attached to the above, corrugated paper coated with a powdery porous material to form a honeycomb structure, and the like.

The metal contained in the metal carboxylate attached to the porous material is not particularly limited, but for example, one or more of iron, chromium, nickel, cobalt, manganese, copper, magnesium, zinc, calcium and the like are used. It is possible.

The carboxylic acid residue contained in the metal carboxylate is not particularly limited. For example, a monobasic acid such as formic acid, acetic acid, and propionic acid, a dibasic acid such as oxalic acid, malonic acid, and succinic acid, and a polybasic acid such as a tribasic acid or more can be used. Further, two or more kinds of carboxylates may be mixed and used.

The amount of the metal carboxylate to be added to the porous substance is preferably 1.0 to 20.0 parts by weight, and more preferably 2 to 10 parts by weight, based on 100 parts by weight of the porous substance. If the amount of impregnation is less than 1.0% by weight, the effect of impregnating the organic acid residues and metal ions contained in the metal carboxylate will be poor, and if the amount of impregnation exceeds 30.0% by weight, the adsorptivity of the porous substance will be slightly impaired. This is because the tendency is recognized.

A porous substance having a metal carboxylate impregnated feels no odor like organic amine impregnated carbon even if a metal carboxylate in an amount sufficient to act as a decomposition catalyst for malodorous components is impregnated. In addition, it also has an excellent function as a malodor decomposition catalyst.

The air purification agent of the present invention can be obtained by further mixing activated carbon with a porous substance impregnated with a metal carboxylate. In the present invention, in addition to being sometimes used as a carrier for metal carboxylate, the specific surface area and other properties of the activated carbon used as one component of the air purification agent adsorbent are as follows. Is the same as.

To prepare the air purifying agent of the present invention, an aqueous metal carboxylate solution is used to impregnate the porous substance.
Specifically, it is obtained by adsorbing a metal salt on a porous body by an adsorption method or a sprinkling method, and then drying at 100 ° C. or higher.

In addition, as a method of impregnating a metal carboxylate, it may be prepared by sprinkling an organic acid and a metal salt on a porous material. As the organic acid, a monobasic acid such as formic acid, acetic acid and propionic acid, a dibasic acid such as oxalic acid, malonic acid and succinic acid, and a polybasic acid such as a tribasic acid or more can be used. Further, as the metal salt, iron, chromium, nickel, cobalt,
Carbonates or hydroxides of one or more metals of manganese, copper, magnesium, zinc and calcium can be used. These organic acid and metal carbonate or hydroxide are attached to the porous material, and a metal carboxylate is formed on the surface of the porous material during the process of preparing by drying at a high temperature.

The porous substance attached by any of the methods also exhibits high adsorption performance for acetaldehyde and other malodorous substances.

[0036]

[Function] The mixture of the porous material and the activated carbon with the metal carboxylate impregnated after the impregnation as compared with the case where the mixture contains the same amount of the metal ion or the organic carboxylic acid as the other compound. Not only is the acetaldehyde adsorptivity less deteriorated over time, but the acetaldehyde adsorptivity immediately after attachment is also high. That is, there is little deterioration in acetaldehyde adsorption performance as an air purifier, and
It also has excellent characteristics with high initial activity.

Further, even when the air purifying agent was heated to 150 ° C., no decomposition of the metal carboxylate was observed and no deterioration in aldehyde adsorption performance was observed. It is considered that this action is due to the fact that the organic acid stabilizes the metal ion, but the details of the mechanism are not clear.

Further, the metal carboxylate is attached to the macropores, cracks or surface portions of the porous material, the activity of the micropores is not significantly reduced, and the adsorption of hydrocarbons is relatively excellent. When the amount of carboxylate added exceeds 20% by weight, the adsorption rate of aldehyde gradually decreases, and when it exceeds 10%, it becomes acidic and the adsorbability of hydrogen sulfide or acetaldehyde or the function as a decomposition catalyst slightly decreases. . Therefore, in order to further enhance the aldehyde adsorption capacity, it is necessary to newly add activated carbon having alkalinity. On the other hand, when the adsorptivity or decomposition catalytic property of hydrogen sulfide or acetaldehyde or the adsorptivity of hydrocarbon is further enhanced, it is necessary to increase the mixing ratio of the non-impregnated activated carbon.

The porous substance in which the metal carboxylic acid salt is impregnated also adsorbs and adsorbs these components by the neutralization reaction of ammonia and carboxylic acid or the formation of a complex salt with a metal ion.
It has excellent removability. Therefore, by adjusting the mixing ratio of the air purifying agent according to the property of the odor to be removed, it has a function of efficiently removing most of the bad odor and has a characteristic that it can be maintained for a long time.

In the room of a living space such as an office or a home, the odor of tobacco is usually strongly felt, but as the malodorous components contained in the air, acetaldehyde, ammonia, hydrocarbons, hydrogen sulfide, methyl zinc, and other organic substances are used. There are metal compounds and the like. Among these components, the purifying agent of the present invention is extremely excellent in adsorbability of acetaldehyde, which is a main component of tobacco odor, and also contains a porous substance and activated carbon impregnated with a metal carboxylate, so that ammonia, hydrocarbon,
It also has a high adsorption / removal property for components such as hydrogen sulfide and has an excellent function as an air purifier.

The adsorbent of the present invention is excellent in adsorbing almost all malodorous components contained in living spaces such as offices, cars, and homes, and has a high adsorbing speed, so that various adsorbents such as filters, minute cells and baffles can be obtained. It is effective as an air purification device incorporated so as to come into contact with air in various forms.

[0042]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

(Examples 1 to 7, Comparative Examples 1 to 3) As the activated carbon, coconut shell charcoal was steam activated to obtain a particle size of 6 to 6.
Using 12-mesh crushed activated carbon, metal carboxylate was impregnated with activated carbon, granular zirconia and titanium oxide sintered body in the ratio shown in Table 1, and then mixed with a predetermined amount of non-impregnated activated carbon and air. Purifying agents (Examples 1-7) were prepared. Further, for comparison, an air purifying agent (Comparative Example 2) including only activated carbon impregnated with a metal oxide (Comparative Examples 1 and 3) and non-impregnated activated carbon was prepared.

The metal carboxylate-impregnated porous substance was prepared by sprinkling a predetermined amount of metal carboxylate onto activated carbon or other porous substance while impregnating it and then drying at 200 ° C.

[0045]

[Table 1]

2 g of each sample prepared by mixing at the ratio shown in Table 1 was taken and placed in a glass bottle having a capacity of 3.97 liters, and then a predetermined acetaldehyde was injected and vaporized.
Next, the sample was left in a thermo-hygrostat at 25 ° C and 60% RH, and the acetaldehyde concentration after 24 hours was measured by a detector tube to measure the adsorbed amount of acetaldehyde in the sample. In this way, the adsorption amount at an acetaldehyde gas concentration of 0.1 to 100 ppm was measured to create an isotherm adsorption line, from which the adsorption amount at an acetaldehyde gas concentration of 10 ppm was displayed.

Similarly, the adsorption amount at 10 ppm for ammonia, 1 ppm for hydrogen sulfide and 5 ppm for benzene was shown.
The gas concentration of ammonia is measured by a gas detector tube, and the gas concentrations of hydrogen sulfide and benzene are measured by FPD (flame photometric dete
It was quantified by a high-sensitivity gas chromatograph with ctor). The results are shown in Table 1.

The results shown in Table 1 show that the Examples are superior to the Comparative Examples in the adsorbability of acetaldehyde and show a balanced adsorption performance for the whole malodorous substance. The amount of the metal carboxylate added to the porous material is preferably 1.0 to 20.0 parts by weight, more preferably 2 to 10 parts by weight, based on 100 parts by weight of the porous material.

Further, the adsorption performance for acetaldehyde, hydrogen sulfide, methyl mercaptan and trimethylamine can be changed by changing the composition of each activated carbon little by little. Further, an adsorbent suitable for the composition of ammonia or other malodorous gas can be prepared by increasing or decreasing the amount of metal carboxylate impregnated on the activated carbon.

For example, kitchen air with a high content of mercaptan, fish odors with a lot of odors such as amines and ammonia, pet odors, sulfur-containing compounds, raw garbage odors with vegetables containing a lot of hydrocarbons, toilet odors, etc. For leather odor, an adsorbent having a high ratio of metal carboxylate-impregnated activated carbon is preferable.

Next, an air purifying filter and an air purifying apparatus using the air purifying agent of the present invention will be described. The air purifying agent used here was prepared in Examples 1 and 2 and Comparative Example 2. FIG. 1 (a) is a sectional view of the air purification filter of the present invention, and FIG. 1 (b) is an enlarged view of a part thereof.
1 is an air purifying filter body, 2 is a kraft paper honeycomb-shaped substrate, the size of which is 25 mm in cell size, 7 mm in thickness,
The area is 0.120 m ² , and the filling amount of the air purifying agent 3 is 300 g.
Further, 4 is a non-woven fabric, which is an electret non-woven fabric made of thermoplastic resin fibers such as polyester, acrylic, polypropylene, polyethylene, etc., and has some elasticity like cotton. The unit weight is 10 to 30 g / m ² , and the pressure loss is 0.5 mmAq or less when the wind speed is 1 m / sec.

As the adhesive sheet 5 for joining the honeycomb-shaped base material 2 and the non-woven fabric 4, a solventless type heat-fusible resin (polymer such as nylon or acrylic) is made fibrous.
In addition, a non-woven fabric having a high aperture ratio, that is, a so-called spider web sheet is used.

In order to assemble the air purifying filter, first, the honeycomb-shaped substrate 2 and the non-woven fabric 4 are joined on one side only by hot pressing or the like using the spider web-shaped adhesive sheet 5.
Next, the air purifying agent 3 is evenly sprayed from above. Further, the spider web-shaped adhesive sheet 5 is placed thereon and heated by a hot press or the like to complete the filter.

The air purifying filter thus obtained is used by incorporating it into the air purifying device 6 as shown in FIG. Reference numeral 7 is an air inlet, 8 is an air outlet, 9 is a control panel, and 10 is a filter mounting jig. FIG. 3 shows a horizontal sectional view of the air purification device. The air purification filter is set by the jig 10 as shown in FIG. Reference numeral 11 is a dust removal filter for removing coarse dust contained in air, 12 is a motor, 13 is a fan, and 14 is an air flow passage.

The air purification apparatus thus obtained is
It was placed in a box made of acrylic resin with a capacity of 1 m ³ , and introduced into the acrylic box so that the initial concentration of acetaldehyde and ammonia was 50 ppm and the initial concentration of hydrogen sulfide was 100 ppm. After that, the air purifier was operated at an air flow rate of 2.8 m ³ / min to measure the operation time and the residual odor amount, and an adsorption decay curve was created. The results are shown in FIGS. 4, 5 and 6.

In addition, acetaldehyde is FID (flame ioniza)
High-sensitivity gas chromatograph with ionization detector), the concentration of ammonia was detected with a gas detector tube, and hydrogen sulfide was quantified with a high-sensitivity gas chromatograph with FPD.

As is clear from these results, the air purifying agents having the compositions shown in the examples of the present invention maintain the adsorbed amounts of other odorous components substantially, and in particular the adsorbing ability of acetaldehyde and ammonia. It can be seen that the sustainability is high.

[0058]

Industrial Applicability The air purifying agent of the present invention is one of the largest causes of the bad odor in the air, and is effective in adsorbing / removing lower aliphatic aldehydes contained in cigarette smoke, especially acetaldehyde. Are better. Further, the purifying agent not only has high initial activity, but also has a small degree of reduction in acetaldehyde decomposing ability with the lapse of time after attachment, and can maintain its effect for a long period of time. Further, since it has a high adsorption / removal property for malodorous components other than acetaldehyde contained in the living space, it has an excellent function as an air purifying agent or an air purifying apparatus incorporating this purifying agent.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional view of one embodiment of the air purification filter of the present invention, and FIG. 1 (b) is an enlarged view of a part thereof.

FIG. 2 shows a perspective view of one embodiment of the air purifying apparatus of the present invention.

FIG. 3 is a horizontal sectional view of the air purifier shown in FIG.

[Explanation of symbols]

 1 Filter Main Body 2 Honeycomb-like Base Material 3 Air Purifying Agent 4 Nonwoven Fabric 5 Adhesive Sheet 6 Air Purifying Device Main Body 7 Air Intake Port 8 Air Blow Out Port 9 Control Panel 10 Filter Fixture 11 Dust Filter 12 Motor 13 Fan 14 Air Flow Passage

FIG. 4 shows the relationship between the operating time of the air purification device and the acetaldehyde residual rate.

FIG. 5 shows the relationship between the operating time of the air purification device and the residual ammonia ratio.

FIG. 6 shows the relationship between the operating time of the air purification device and the residual hydrogen sulfide rate.

[Explanation of symbols]

 15 Example 1 16 Example 2 17 Comparative Example 2

Claims (4)

[Claims] 1. An air purification agent obtained by mixing activated carbon with a porous substance impregnated with at least one metal carboxylate. 2. The air purifying agent according to claim 1, wherein the porous substance is activated carbon. 3. The air according to claim 1 or 2, wherein the porous substance impregnated with at least one kind of metal carboxylate is obtained by impregnating 100 to 100 parts of the porous substance with 0.5 to 30 parts of metal carboxylate. Purifying agent. 4. An air purifying device comprising an adsorbent, which is a mixture of a porous material impregnated with at least one kind of metal carboxylate and activated carbon, as an air purifying agent.