JP2001179016A - Air cleaning filter medium and filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the deodorizing efficiency of a malodorous substance which pollutes indoor air, to prevent the lowering of the capacity of fibrous activated carbon within a short period of time and to reduce the weight and thickness of a filter while enhancing the workability of the filter. SOLUTION: In a sheetlike or pleated filter medium comprising a plurality of layers made of a nonwoven fabric using binder fibers, at least one layer is a first adsorbing layer impregnated with a water-soluble chemical agent chemically reacted with an indoor malodorous substance and other one layer is a second adsorbing layer wherein fibrous activated carbon is fixed by binder fibers and the first and second adsorbing layers are bonded by spot lump parts formed by an ultrasonic bonding method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a work / living environment for humans (hospitals, houses, automobiles, pet shops, etc.) and a storage / exhibition environment for fine arts such as paintings (gallery, art museum, etc.) The present invention relates to an air purifying filter and a filter that adsorb and remove stench substances that cause discomfort to humans and damage art works.

[0002]

2. Description of the Related Art At present, in order to purify contaminated air, a filter medium which is obtained by spraying granular activated carbon onto a porous substrate (such as a nonwoven fabric sheet or urethane home) coated with an emulsion resin (mainly an acrylic adhesive), A filter medium obtained by mixing powdered activated carbon with an emulsion resin and adhering to a porous substrate is used as an activated carbon filter.

[0003] However, this type of activated carbon filter has a problem that the activated carbon adsorption performance is not sufficiently exhibited and the deodorization performance is low because the activated carbon is covered with the emulsion resin and the activated carbon falls off during handling. .

[0004] In addition, general activated carbon is mainly physically adsorbed, has a small number of micropores involved in gas adsorption, and has an extremely small adsorption removal capacity, so that it does not function as an adsorbent for lower aldehydes and polar gases. was there.

Therefore, recently, for the purpose of improving the adsorption performance of activated carbon, a so-called functional activated carbon obtained by impregnating granular activated carbon or fibrous activated carbon with various chemicals that chemically adsorb or catalytically react with a specific malodorous substance. Has been developed, and filter media using various functional activated carbons have been used as chemical adsorption filters.

However, in this type of chemical adsorption filter, the micropores involved in the adsorption of particulate or fibrous activated carbon gas are sealed by the chemical impregnation treatment, and the effective specific surface area decreases. There was a problem that the performance of the activated carbon itself was not sufficiently exhibited, the performance deteriorated in a relatively short period of time, and the deodorization rate of lower aldehydes and polar gases was poor.

[0007] Some commercially available air purifiers have an activated carbon filter and a chemical adsorption filter arranged adjacent to each other. However, the air purifier has the same problems as those of the prior art described above, and requires a lot of trouble in installation. In other words, there is a problem that the weight increases.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art, and has an object to improve the removal rate of malodorous substances contaminating indoor air and to reduce the production of fibrous activated carbon in a short period of time. It is an object of the present invention to prevent a decrease in performance, to reduce the weight and thickness of a filter, and to improve workability.

[0009]

The air purifying filter of the present invention is a sheet or pleated filter comprising a plurality of layers of non-woven fabric using a binder fiber, at least one of which has a chemical reaction with indoor odorous substances. The first adsorption layer solidified between the fibers of the constituent fibers and the fiber entangled portion of the water-soluble drug,
Another one layer is a second adsorption layer in which fibrous activated carbon is fixed with binder fibers, and the first adsorption layer and the second adsorption layer are bonded by a point-like mass formed by an ultrasonic bonding method. Consisting of

According to this means, the first adsorbent layer containing the agent which chemically reacts with the indoor odor substance and the second adsorbent layer containing the fibrous activated carbon are each constituted by a non-woven fabric using a binder fiber. Because it is adhered at the lumpy part,
The micropores that are directly opened on the outer surface of the fibrous activated carbon of the second adsorption layer are not deactivated by the impregnated drug or the nonwoven fabric emulsion resin as in the prior art,
In addition, the performance of the fibrous activated carbon of the second adsorption layer is sufficiently exhibited.

Here, the indoor odor substance means a low molecular weight odor substance such as a lower aldehyde and a polar gas, among the malodorous substances that pollute the interior of the room.

[0012] The water-soluble chemical that chemically reacts with the indoor odor substance means a water-soluble chemical that neutralizes or condenses with a lower aldehyde or a polar gas. Examples of the water-soluble drug include lower aldehydes and acid gases (NO _x , SO
amines (ethanolamine, aniline, anisidine, etc.) are used for _x , sulfur compounds, acetic acid, etc.
For basic gases (ammonia, methylamine, trimethylamine, etc.), acidic chemicals (citric acid, malic acid,
Organic acids such as succinic acid).

In the present invention, the constituent fibers of the first adsorptive layer contain at least one or more drugs. When the first adsorbent layer is composed of multiple layers, the constituent fibers of each layer have different indoor odor substances and chemicals. It is preferable to include a water-soluble drug that reacts. In this way, different indoor odor substances are efficiently adsorbed and removed in each layer of the first adsorption layer. Further, since one filter medium has both functions of chemical adsorption and physical adsorption, it is possible to reduce the weight and thickness of the filter and to improve the workability.

Next, as the air purifying filter of the present invention, the air purifying filter is left in sheet form or pleated so as to increase the contact area with the air flow. It is mounted on the frame so as to be located on the inflow side. In this way, the first adsorption layer acts as a chemical adsorption layer for efficiently adsorbing and removing indoor odorous substances, so that no load is applied to the fibrous activated carbon of the second adsorption layer, and the performance as a physical adsorption layer is extended. It can be fully demonstrated over a period.

[0015]

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, an air purifying filter medium F is formed by adhering a first adsorbent layer 1 and a second adsorbent layer 2 with a plurality of dot-like masses 3 interspersed.

The first adsorptive layer 1 is formed by mixing a binder fiber and a thermoplastic fiber in a predetermined ratio and performing a predetermined process to impregnate a sheet-like nonwoven fabric into an aqueous solution of a drug, thereby forming a water-soluble drug into a constituent fiber. It is solidified between the fibers and between the fiber entangled portions and adhered in a predetermined amount.

In this case, as the constituent fibers of the first adsorption layer 1, thermoplastic fibers are mixed, but the binder fibers may be 100%. However, in order to obtain the required thickness as a filter medium, it is better to mix thermoplastic fibers, and the mixing ratio (weight ratio) of binder fibers and thermoplastic fibers is as follows:
The ratio may be adjusted in the range of 9: 1 to 5: 5. In this range, the amount of the binder fiber is increased in consideration of the strength as the filter medium and the pleating property, and the amount of the thermoplastic fiber is increased in consideration of the thickness and cost. is there.

The second adsorbing layer 2 is formed by mixing fibrous activated carbon and binder fibers at a predetermined ratio, performing light needle punching, and then calendering to form a sheet.

In this case, the mixing ratio of the fibrous activated carbon and the binder fiber in the second adsorption layer is from 9: 1 to 5: 5 in consideration of the deodorizing performance of the malodorous substance, the strength as a filter medium, the pleating property, and the like. Is more preferable, and more preferably, it is in the range of 8: 2 to 6: 4.

The fibrous activated carbon is obtained by carbonizing a polymer fiber, and may be any of phenol type, pitch type, acrylonitrile type and the like.
In consideration of performance, it is preferable to use a pitch type.

As the material of the binder fiber and the thermoplastic fiber constituting the filter medium, chemical fibers such as polypropylene, polyester, nylon, polyethylene, vinylon and rayon can be used alone or in combination of two or more. As the binder fiber, any of a single component type and a composite component type (parallel type, core-sheath type) may be used, and a known fiber may be used.

Further, as the water-soluble drug, there are ethanolamine, aniline, and the like for lower aldehyde and acid gas.
Amine-based drugs such as anisidine and organic acids such as citric acid, malic acid and succinic acid can be used for a basic gas. Ethanolamine is more preferably triethanolamine, and organic acid is more preferably oxycarboxylic acid such as malic acid or citric acid, which has low volatility and high affinity for water.

By the ultrasonic bonding method, the point-like lump that adheres the first adsorbing layer and the second adsorbing layer is formed by passing the constituent fibers excluding the fibrous activated carbon of each layer through the laminating surface to the inside of the filter medium. And can be formed by melt-curing.

The above-mentioned filter medium is left as a sheet or formed into a pleated shape, and mounted on a frame made of wood, metal, synthetic resin, paper, or the like so that the first adsorption layer is on the air inflow side. A desired filter can be formed.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments.

A fibrous web in which binder fibers (low-melting-point polyester fibers) and thermoplastic fibers (high-melting-point polyester fibers) are mixed at a weight ratio of 8: 2 is subjected to calendering to obtain a nonwoven fabric sheet having a basis weight of 80 g / m ² . Was prepared. Subsequently, this nonwoven fabric sheet was treated with an aqueous citric acid solution (30
%) And a triethanolamine aqueous solution (20%), and then squeezed and rolled so that the amount of each drug adhered was 50 g / m ² , thereby producing a first adsorption layer. By the way, the amount of drug attached is not limited to the above numerical values,
At least 20 g / m ² or more is sufficient.

Further, petroleum pitch-based fibrous activated carbon and binder fiber (low melting point polyester fiber) are mixed in a weight ratio of 7:
Needle punching is performed on the fibrous web mixed at a ratio of 3 at a rate of 50 pieces / cm ² , and then calendering is performed.
A second adsorption layer made of a nonwoven fabric sheet of g / m ² was prepared.

Next, the first adsorbent layer and the second adsorbent layer are overlapped, and the constituent fibers excluding the fibrous activated carbon of each layer penetrate the laminating surface and are passed through the laminating surface using an ultrasonic heat fusion device. A large number of dot-like mass portions melt-hardened in step were formed to obtain a joined filter material for air purification.

(Comparative Example 1) Fibrous activated carbon has a basis weight of 100 g
/ M ² , mixed with polyester fibers to form a sheet, sandwiched between polyester spunbond nonwoven sheets, and subjected to needle punching at 50 P / cm ² to produce a filter medium.

Comparative Example 2 A filter medium was prepared in the same manner as in Comparative Example 1 using functional activated carbon.

The JEM-14 standardized by the Japan Electrical Manufacturers' Association using the filter media of the above example and comparative examples 1 and 2.
When the following deodorizing performance test was carried out in accordance with 67-1995, the results shown in Table 1 and FIG. 2 were obtained.

The above-mentioned deodorizing performance test refers to a closed box made of an acrylic plate (volume 1) in which an air purifier and a cigarette smoking machine (one capable of simultaneously absorbing five cigarettes) are arranged.
Within m ³ ), five cigarettes (equivalent to the brand Mild Seven) are smoked with a cigarette smoker, and the initial concentrations of three gas components (ammonia, acetaldehyde, and acetic acid) in the cigarette smoke are measured, and then the air cleaner is used. Each sample (area 0.1 m ² ) of each filter medium of Example and Comparative Examples 1 and ² was
This is a method in which the gas concentration in the box after the operation for one minute is measured with a detector tube (manufactured by Gastech Co., Ltd.) to calculate the removal rate. Then, the above operation was repeated to calculate the number of tobaccos that could be processed by the time the removal rate became 50% or less. In addition,
The test conditions were a processing air volume of 2.8 m ³ / min and a wind speed of 0.4.
m / sec.

[0034]

[Table 1]

As is clear from Table 1 and FIG. 2, it was found that the Example significantly improved the removal rate of any of ammonia, acetaldehyde and acetic acid gas as compared with Comparative Examples 1 and 2.

Next, a filter (H610.times.W610.times.D65 mm) in which the filter medium of the example was mounted on an aluminum outer frame was subjected to a filtration performance test in accordance with JIS B 9908 type 2, and the initial pressure loss was 108.8 Pa and the final pressure loss was 108.8 Pa. Pressure loss 2
It was 94.0 Pa, the dust retention capacity was 254 g / unit, and the average dust removal rate was 82.0%. Thus, it was found that the filter can be sufficiently used as a filter for an air purifier. The dust used was JI
11 or 3 mg / m ³ of SZ8901 _{(Jochiriritsu),} using the 15 kinds 70 mg / m ³ (dust holding capacity), the test conditions were a temperature 20 ° C., humidity 58.0%, an air volume 56m ³ / min.

[0037]

According to the filter medium of the present invention, it is possible to eliminate a decrease in the deodorizing performance of the fibrous activated carbon during production.
In addition, the first adsorbent layer reliably absorbs and removes indoor odorous substances, and the fibrous activated carbon of the second adsorbent layer fully demonstrates its deodorizing performance, thereby improving the removal rate of malodorous substances that pollute indoor air. In addition to this, it is possible to prevent the performance of the fibrous activated carbon from being deteriorated in a short period of time, and it can be used for a long period.
Further, since one filter medium has both functions of chemical adsorption and physical adsorption, it is possible to reduce the weight and thickness of the filter and to improve the workability of mounting the filter medium.

According to the filter for air purification of the present invention, the indoor odor substance in the contaminated air can be adsorbed and removed by the first adsorption layer in advance, so that the load of the malodorous substance is applied to the fibrous activated carbon of the second adsorption layer. Its performance can be fully exhibited without any need, it can be used for a long time, and a clean air environment can be created. In addition, since it has good dust collection rate, pressure loss, and dust holding capacity as well as a deodorizing filter of an air purifier, it has an excellent effect that it can be used as a medium-performance filter of an air conditioner.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a filter medium of the present invention.

FIG. 2 shows gas removal rates showing the deodorizing performance of an example and a comparative example, in which (a) is a comparison chart of ammonia, (b) is acetaldehyde, and (c) is acetic acid.

[Explanation of symbols]

 F: filter medium 1 ... first adsorption layer 2 ... second adsorption layer 3 ... point-like mass

Claims (3)

[Claims] 1. A sheet or pleated filter medium comprising a plurality of layers of a nonwoven fabric using binder fibers, wherein at least one layer contains a water-soluble agent chemically reacting with a room odor substance between fibers of the constituent fibers and fiber entanglement. The first adsorption layer solidified in part, the other layer is a second adsorption layer in which fibrous activated carbon is fixed with binder fibers, and the first adsorption layer and the second adsorption layer are bonded by ultrasonic bonding. An air purification filter material characterized by being adhered with the formed dot-like mass. 2. The air purification filter medium according to claim 1, wherein each layer of the first adsorption layer contains a different water-soluble drug. 3. An air purification filter, wherein the air purification filter medium according to claim 1 or 2 is mounted on a frame so that the first adsorption layer is on the air inflow side.