WO2006009341A1

WO2006009341A1 - Air cleaning filter

Info

Publication number: WO2006009341A1
Application number: PCT/KR2004/003271
Authority: WO
Inventors: Seong Hwan Lee; Sung Hwa Lee; Ok Chun Hyun; Young Ki Hong; Myung Suk Lee; Chul Sang Jung; Jong Soon Kim
Original assignee: Lg Electronics Inc.
Priority date: 2004-07-21
Filing date: 2004-12-13
Publication date: 2006-01-26
Also published as: KR100606980B1; KR20060008508A

Abstract

An air cleaning filter and a manufacturing method thereof are provided. The air cleaning filter is coated with a silver and enzyme. The method for manufacturing the air cleaning filter includes the step of fixing the enzyme on the carrier by processing the enzyme on the carrier coated on the silver, or includes the step of immersing the carrier in a mixed solution of the silver and the enzyme onto the carrier. Accordingly, the air cleaning filter coated with the silver and the enzyme can directly hydrolyze cell wall of the microorganism, such as a bacteria, a microbe or a fungus, and destruct cell membrane of the microorganism. Also, the air cleaning filter can convert oxygen into active oxygen and thus effectively steriolize the microorganism floating in the air.

Description

AIR CLEANING FILTER

Technical Field

The present invention relates to an air cleaning filter, and more particularly, to an air cleaning filter for removing microorganisms floating in the air and a manufacturing method thereof, in which silver and enzyme are coated on a carrier for the air cleaning filter.

Background Art

With the increasing interest in the environment, an indoor air cleaner has been demanded. Accordingly, various air cleaners for removing foreign substances have been developed. Such air cleaners use an air cleaning filter. The air cleaning filter has various shapes and features according to kind, size and characteristic of the object that needs to be removed and therefore various filters have been developed. Specifically, for a satisfactory air cleaning effect, such an air cleaning filter must have an antimicrobial property so as to sufficiently remove microorganisms, such as a bacteria, a microbe and a fungus, which are floating in the air.

Disclosure of Invention

An object of the present invention devised to solve the problem lies on an air cleaning filter, which can sterilize and germicide microorganism floating in the air.

Another object of the present invention devised to solve the problem lies on a method for manufacturing an air cleaning filter, which can sterilize and germicide microorganism floating in the air.

The object of the present invention can be achieved by providing an air cleaning filter having a carrier coated with a silver and an enzyme. In another aspect of the present invention, provided herein is a method for manufacturing the air cleaning filter, including the steps of: coating a silver on a carrier; and fixing an enzyme on the carrier by processing the enzyme on the carrier coated with the silver. Alternatively, the method includes the step of immersing the carrier in a mixed solution of the silver and the enzyme or spraying the mixed solution onto the carrier.

There is no special limit in kind, type, size and a manufacturing method of the carrier, only if it can perform an air cleaning function. For example, the carrier includes a glass fiber, an ion exchange fiber, a cellulose fiber or an asbestos fiber, various kinds of organic fiber, various kinds of inorganic fiber, and so on. Also, a metal, such as zinc, copper and aluminum, or a plastic can be used. In addition, theses carriers can be variously modified depending on characteristics of the materials. Further, the carrier can be a honeycomb type, a particle type, a net type, a filter paper type, a cotton type, a mesh type, a plate type or a foam type.

Any kind of silver can be used if only it has a germicidal power. For example, a nano silver or a colloidal silver can be used. At this point, it is preferable that the silver is activated so sufficient that it can be coated on the carrier. The nano silver represents a nano-sized silver particle. There is no special limit in a manufacturing method of the nano silver. That is, any nano silver can be used only if it is a particulate silver of 1 nanometer in size. Preferably, a dispersion solution of a nano-sized composite material can be used according to a method disclosed in Korean Patent Application Laid-Open Publication No. 2004-0018227. That is, the dispersion solution of nano-sized composite materials is prepared by the steps of: preparing a basic colloidal silica solution; preparing an electrolysis apparatus by putting a negative electrode containing aluminum and _^a positive electrode containing silver in the silica colloidal solution; and forming a nano- sized composite material by applying voltage to each electrode. The silver used in the present invention destructs a cell membrane of bacteria and converts an oxygen into an activated oxygen, thereby providing a strong antibacterial function.

Regardless of shape, any enzyme can be used if only it has a property of bacteriolytic property. The enzyme may be one selected from the group consisting of lysozyme, chitinase, protease, glucose oxidase, glucanase, β-galactosidase, endo-β-N- acetylglucosamunidase, endolysin, and combinations thereof. There is no special limit in the concentration of the enzyme. That is, the concentration of the enzyme can be properly adjusted depending on the characteristic of target bacteria and the required degree of the pollution. Specifically, the lysozyme is an enzyme that acts on a peptidoglycan of cell membrane and hydrolyzes β-l,4-muramide bond between N-acetyl muramic acid and

N-acetylglucosamine. Therefore, the lysozyme has an excellent sterilization function together with the silver.

The air cleaning filter coated with the silver and the enzyme can be manufactured by coating the silver on the carrier and fixing the enzyme on the carrier. Alternatively, the air cleaning filter coated with the silver and the enzyme can be manufactured by immersing the carrier in a mixed solution of the silver and the enzyme or spraying the mixed solution onto the carrier.

That is, the air cleaning filter coated with the silver and the enzyme can be manufactured by sequentially coating the carrier with the silver and the enzyme, or immersing the carrier in the mixed solution of the silver and the enzyme and then spraying the solution onto the carrier.

According to another method for manufacturing the vitamin C emitting filter, the step of coating the carrier with the silver is performed by the general methods and a suitable method can be selected depending on the property of the carrier. Also, the step of fixing the enzyme on the carrier coated with the silver can be performed by a general method, without any special limit. Chemical and physical methods can be used to fix the silver on the carrier. For example, the nano silver can be coated on the carrier by a spray method and the enzyme can be coated on the carrier by spraying an activated enzyme thereon. While a known technology such as an air spray can be used as the spraying method, the present invention is not limited to it. That is, any method can be used only if it evenly coats the silver and the enzyme on the carrier. In addition to the spray method, an immersion method can be used.

Further, the air cleaning filter coated with the silver and the enzyme can be manufactured by activating the enzyme with EDTA or glycine and then adding the nano silver. However, the present invention is not limited to it. That is, the silver and the enzyme can be coated by a general method, without any special limit. The silver and the enzyme can be coated on the carrier by spraying the mixed solution of the silver and the enzyme. The carrier may be cleansed with a proper cleaning water before coating the carrier with the silver and the enzyme or the cleaned carrier may be dried by a heat treatment. In the case of a metal carrier, it is preferable to remove an oil component attached to a surface of the carrier during the manufacturing process or storage. In case where the carrier is dried, a drying time and a drying temperature can be properly adjusted depending on a shape, kind and size of the carrier. Further, a drying step can be performed after coating the carrier with the silver and the enzyme. In case where the

aluminum mesh is used, it is dried at about 70°C for forty minutes in the oven.

The germicide function of the air cleaning filter coated with the mixed solution of the silver and the enzyme is shown in FIG. 3. The vitamin C emitting filter according to the present invention, is cut with a desired size and used as a filter for the air cleaner. In addition, the filter according to the present invention can be used singly in the same product and can be used together with the air cleaner filter and the deodorizer filter.

The vitamin C emitting filter according to the present invention can be widely used in the home or business air cleaners, vehicles, refrigerators, humidifiers, air conditioners, and other home appliances. The mounting position and shape of the filter can be appropriately adjusted depending on the products.

Brief Description of Drawings The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is a schematic view of a chamber for evaluating a microorganism cleaning performance of an air cleaning filter according to an embodiment of the present invention; FIG 2 is a plan view of the chamber shown in FIG. 1;

FIG. 3 is a TEM image illustrating a process of sterilizing E.coli collected in an air cleaning filter according to an embodiment of the present invention;

FIG. 4 is an image of living bacteria when an air cleaning filter is process with E.coil;

FIG. 5 is an image of living bacteria when an air cleaning filter is processed with staphylococcus aureis;

FIG. 6 is an image of living bacteria when an air cleaning filter is processed with pseudomonas ; and FIG. 7 is an image of living bacteria when an air cleaning filter is processed with mold.

Best Mode for Carrying Out the Invention

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. [Embodiment 1]

An aluminum mesh manufactured by Airfill company is immersed in 2.5% NaOH solution for three minutes, so that an oil component is removed from the aluminum mesh.

Then, the aluminum mesh is cleaned using 2.5% NaOH solution. The above processes are repeated seven times. A heat treatment is performed on the cleaned aluminum mesh

in a drying oven in which a temperature is adjusted to 40°C •

Nano silver is coated on the heat-treated aluminum mesh by using a spray method. Then, a lysozyme manufactured by Sigma company is added to 100 mM EDTA solution, thereby preparing 1000 ppm lysozyme solution. The aluminum mesh coated with the silver is immersed in the lysozyme solution and agitated at a room temperature for six hours, such that the lysozyme is coated on the aluminum mesh. Consequently, the aluminum mesh coated with the nano silver and the lysozyme is obtained. [Embodiment 2]

A NaH₂PO₄ hydrate and a pure water are mixed in a ratio of 1 :32 and a Na₂HPO₄ hydrate and a pure water are mixed in a ratio of 1:18.6. Finally, a 1/15M phosphate buffer solution (pH=7) is prepared. Then, 100 mM EDTA solution is obtained by adding

EDTA to the phosphate buffer solution. A lysozyme solution whose final concentration is 10000 ppm is manufactured by adding lysozyme to the 100 mM EDTA solution, hi addition, silver coating solution whose final concentration is 1000 ppm is manufactured by adding acryl emulsion, propylene glycol and polysiloxane to a colloidal nano silver. Then, 1000 ppm solution is manufactured by adding the lysozyme solution to the silver coating solution, and the resulting solution is agitated 100-200 rpm at a room temperature for six hours, thereby manufacturing a silver/enzyme coating solution.

By using an air spray method, the silver/enzyme coating solution is sprayed on the aluminum mesh, which is cleaned and heat-treated in the method of the first embodiment, thereby coating the silver and the enzyme on the aluminum mesh. Then, the aluminum

mesh is dried at 70°C for two minutes. In this manner, the air cleaning filter coated with

the silver and the enzyme according to the present invention is obtained. [Experimental Example 1] In order to measure the antibacterial performance of the air cleaning filter obtained in the above embodiments, the aluminum meshes coated with the silver and the lysozyme according to the first and second embodiments of the present invention are placed in a chamber for evaluating a microorganism cleaning performance, as shown in FIG 1. The chamber has a volume of 1000 cm³. An aerosol generator is connected to a bacteria dispenser, model 256 of Royco Instrument Incorporation, and E.coli is dispersed from the bacteria dispenser. The chamber is polluted with 100000 CFU/ml E.coli and air is circulated using a fan disposed in the chamber. After thirty minutes, sixty minutes and ninety minutes, specimens are sampled at three positions near the wall, three middle positions, and three positions near the door, as shown in FIG. 2. Then, the number of E.coli is counted. Petridishes on which agar plates are put down are placed at the specimen positions so as to obtain the specimen. The result is shown in Table 1.

In order for comparison, the aluminum mesh having no silver and lysozyme coated is tested in the same manner and the number of E.coli is counted (Comparison example 1). Meanwhile, as a result of the counting, the number of E.coli is almost equal at the nine positions. Therefore, the number of E.coli is expressed with one value. [Table 1]

As can be seen from Table 1, the air cleaning filter having a carrier coated with silver and enzyme improves the germicidal effect much more than the air cleaning filter having no silver and enzyme coated.

Also, the aluminum mesh coated with the silver and the lysozyme was tested with respect to E.coli, staphylococcus aureis, pseudomonas, and mold according to JIS Z 2911 at Japan synthetic textile inspection institute, Japan food analysis center and Japan spinning inspection institute. As a result, three positions are almost equal to one another and thus one of them is shown in FIGs. 4 to 7. In FIGs. 4 to 7, (a) represents a living bacteria just after inoculation, (b) represents a living bacteria after twenty- four hours in the aluminum mesh where the silver and the enzyme are not processed, and (c) represents a living bacteria after twenty-four hours after inoculation. Also, the average number of the living bacteria was 240,000 in FIG. 4(a), 210,000 in FIG. 4(b), and 17 in FIG. 4(c), respectively. The average number of the living bacteria was 210,000 in FIG 5(a), 5,000 in FIG. 5(b), and less than 10 in FIG. 5(c), respectively. The average number of the living bacteria was 130,000 in FIG. 6(a), 130,000 in FIG. 6(b), and 180 in FIG. 6(c), respectively. The average number of the living bacteria was 120,000 in FIG. 7(a), 4,900 in FIG. 7(b), and less than 10 in FIG. 7(c), respectively. Like this, the air cleaning filter showed the antibacterial property with respect to four kinds of the bacteria. It can be again confirmed that the air cleaning filter coated with the silver and the enzyme according to the present invention has the antibacterial performance with respect to the microorganism.

According to the present invention, the air cleaning filter is coated with the silver having germicidal function and the enzyme having bacteriolytic function and therefore the sterilization effect for the microorganism can be remarkably improved by maximizing the germicidal ability of the silver and the enzyme.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Industrial Applicability According to the present invention, the air cleaning filter coated with the silver and the enzyme can hydrolyze cell wall of the microorganism, such as a bacteria, a microbe or a fungus, and destruct cell membrane of the microorganism. Also, the air cleaning filter can convert oxygen into active oxygen and thus effectively sterilize the microorganism floating in the air.

Claims

What is Claimed is:

1. An air cleaning filter having a carrier coated with a silver and an enzyme.

2. The air cleaning filter of claim 1, wherein the carrier is a fiber selected from the group consisting of a glass fiber, an ion exchange fiber, a cellulose fiber and an asbestos fiber.

3. The air cleaning filter of claim 1, wherein the carrier is a metal or a plastic.

4. The air cleaning filter of any one of claims 1 to 3, wherein the carrier is one selected from the group consisting of a honeycomb type, a particle type, a net type, a filter paper type, a cotton type, a mesh type, a plate type and a foam type.

5. The air cleaning filter of claim 1, wherein the carrier is an aluminum mesh.

6. The air cleaning filter of claim 1, wherein the silver is a nano silver or a colloidal silver.

7. The air cleaning filter of claim I₅ wherein the enzyme is one selected from the group consisting of lysozyme, chitinase, protease, glucose oxidase, glucanase, β- galactosidase, endo-β-N-acetylglucosamunidase, endolysin, and combinations thereof.

8. The air cleaning filter of claim 7, wherein the enzyme is lysozyme.

9. A method for manufacturing the air cleaning filter of claim 1, comprising the step of fixing the enzyme on the carrier by processing the enzyme on the carrier coated on the silver.

10. A method for manufacturing the air cleaning filter of claim 1, comprising the step of immersing the carrier in a mixed solution of the silver and the enzyme, or spraying the mixed solution of the silver and the enzyme onto the carrier.

11. The method of claim 9 or 10, further comprising the step of cleaning the carrier before coating the carrier with the silver and the enzyme.

12. The method of claim 11, further comprising the step of drying the carrier after the cleaning step.

13. The method of claim 9 or 10, further comprising the step of drying the carrier after the carrier is coated with the silver and the enzyme.