KR20020083455A - Photocatalytic coating material having photocatalytic activity and adsorption property and method for preparing the same - Google Patents

Abstract

PURPOSE: Provided are a sol for photocatalyst coating having high adsorption, which can prevent the isolation of secondary contaminant generated due to momentary photocatalytic reaction, and which has high photocatalytic activity, and a method for producing the same. CONSTITUTION: The sol consists of 0.1-20 wt% of photocatalyst, 0.1-10 wt% of inorganic adsorbent, 1-20 wt% of inorganic binder, and 55-95 wt% of organic solvent. The sol further comprises 0.1-10 wt% of metal compound. The metal compound is any one of copper compound, silver compound, bengala, vermilion, cadmium red, loess, cadmium yellow, emerald green, chromium oxide green, prussian blue, cobalt blue, manganese or carbon black. The photocatalyst is selected from TiO2, ZnO2, ZnO, CaTiO, WO3, SnO2, MoO3, Fe2O3, InP, GaAs, BaTiO3, KNbO3, Fe2O3 or Ta2O5.

Description

Photocatalytic coating material having photocatalytic activity and adsorption property and method for preparing the same}

The present invention relates to a photocatalyst coating sol and a method for manufacturing the same, and more particularly, to a photocatalyst coating sol which simultaneously exhibits high adsorption and photocatalytic activity using an inorganic binder, such as meshes such as metals such as stainless steel, and aluminum Plastics such as non-ferrous metals, non-woven fabrics, ceramic filters and polyethylene (PE) filter is applied to the environmental purification system by coating at room temperature with a spray method, dipping method and the like.

As a conventional method for treating environmental pollutants, adsorption, cooling, condensation, chemical cleaning, catalytic oxidation, and biological treatment have been used as physical and chemical methods. However, the adsorption and cooling condensation methods do not solve the contaminant treatment fundamentally, and they are subject to limitations. The chemical liquid cleaning method is a chemical deodorization method through neutralization of contaminants and chemicals. However, in areas with a wide range of pollutant sources, additional equipment is needed to spray the chemicals to effectively react the chemicals and pollutants.In the case of pollutant sources that generate large concentrations of pollutants, a large amount of chemicals are used to neutralize the reaction. There are drawbacks to using. On the other hand, the direct combustion method and the catalytic oxidation method is a method of oxidizing and removing a substance causing pollution, but the removal rate is high, but generates secondary pollutants such as NO _x and SO _x, and there is a problem that the cost is high.

Due to the low initial investment and maintenance costs, biological contaminant removal methods using microorganisms, which are widely used in recent years, have been actively studied in advanced countries such as Europe and North America, and are reaching practical use. This method has the advantage of miniaturizing the device while increasing the pollutant removal rate by immobilizing various microorganisms involved in the pollutant removal to the carrier. However, it is necessary to continuously inject contaminants that act as nutrients necessary for the growth of microorganisms in the reactor where substantial contaminant removal reactions occur, periodically wash the carriers, manage microorganisms, and technical problems such as continuity of operation. There is.

Recently, in order to solve the above-mentioned problems, there is increasing interest in a method for removing contaminants and odorous substances using a photocatalyst, which is one of advanced oxidation techniques. In particular, Korean Patent Application No. 1999-0052838 discloses a filter using a photocatalyst coated with titanium dioxide (TiO ₂ ), zinc oxide (ZnO), silver, and the like on a filter such as nonwoven fabric, activated carbon, and zeolite. No. 2000-0034908 discloses a method for treating volatile organic compounds using a photocatalyst, and the Korean Utility Model Registration Application No. 2000-0029990 discloses a water treatment apparatus using titanium oxide.

The photocatalytic oxidation reaction generates electrons and holes when light energy above band gap energy is irradiated to the photocatalyst, and is a gas or adsorbed on the surface of the photocatalyst due to the strong oxidation power of radicals (· OH) produced by the holes. It refers to a reaction in which a liquid organic matter is decomposed.

That is, the photocatalyst exhibits catalytic activity by absorbing light energy, and oxidatively decomposes environmental pollutants with the strong oxidizing power generated at this time. Materials for inducing the photocatalytic reaction include TiO ₂ , ZnO ₂ , ZnO, SrTiO ₃ , CdS, GaP, InP, GaAs, BaTiO ₃ , KNbO ₃ , Fe ₂ O ₃ , Ta ₂ O ₅ , WO ₃ , SnO ₂ , Bi ₂ O ₃ , NiO, Cu ₂ O, SiO, SiO ₂ , MoS ₂ , InPb, RuO ₂ , CeO _2, etc. are used, and metals such as Pt, Rh, Ag, Cu, Sn, Ni, Fe, etc. are used for the photocatalyst. And these metal oxides can also be added and used. Among them, titanium dioxide (TiO ₂ ) is harmless to the human body, has excellent photocatalytic activity, has excellent light corrosion resistance, and is inexpensive.

The titanium dioxide absorbs and reacts with ultraviolet rays of 388 nm or less to generate electrons (conducting bands) and holes (gap bands). In this case, the ultraviolet rays used as light sources are artificial lights such as lamps, incandescent lamps, and mercury lamps. This can be used. The electrons and holes generated in the reaction recombine in 10 ^-12 to 10 ^-9 seconds, but are decomposed by the electrons and holes if contaminants or the like adsorb to the surface before recombination. The reaction mechanism of this photocatalyst is shown in the following reaction schemes 1 to 5.

^{_{TiO 2 + hν → e - +}} h +

^{_{e - + O 2 → O 2}} - radical

h ⁺ + -OH → -OH radical

O ₂ ^- radical + A (organic, bacteria, pollutant) → A '

-OH radical + B (organic, bacteria, pollutant) → B '

In order to provide a coating having a reaction characteristic of a photocatalyst capable of adsorbing and decomposing contaminants, research has been actively conducted to develop a coating sol containing a photocatalyst (titanium dioxide). In particular, a technique related to antifogging for coating a photocatalyst layer on a transparent substrate such as a mirror, a lens, and a plate glass to prevent the substrate from becoming cloudy or water droplets is disclosed in WO96 / 029375.

In addition, it has been put to practical use in antifouling fields such as filters for air cleaners that deodorize odor components (tobacco smoke) using titanium dioxide as a photocatalyst, filters for antibacterial in water or in the air, and glass and tiles. The photocatalyst coated filter is also applicable to photocatalyst systems for decomposing volatile organic compounds. However, since photocatalytic reaction is a surface reaction, research and development on a technology capable of adsorbing a large amount of organic pollutants or odorous substances on the surface of the photocatalyst is required.

Currently, the photocatalyst coating method through the liquid phase commonly used is a method of making a sol with a titanium alkoxide as a starting material and then coating it on a carrier (Japanese Patent Laid-Open Publication No. H5-253544). The production process is complicated and the production cost is composed of the steps of producing the photocatalytic particles on the carrier, the anatase crystallization step having a high photocatalytic activity, and calcining at 400 to 600 ° C. to give adhesion to the carrier. This is very high disadvantage.

In addition, when using the above method, there are a lot of restrictions to the coating on polymer materials such as plastics that are weak in heat resistance. Furthermore, there is a problem in that power consumption is high even when heat treatment is performed at a high temperature by coating a photocatalyst on tiles and ceramics having excellent heat resistance.

On the other hand, as a photocatalyst coating method via gaseous phase without using a photocatalyst coating sol, there is a sputtering method or a chemical vapor deposition method disclosed in Japanese Patent Laid-Open No. 60-44053. However, even in this case, there is a disadvantage that the initial investment cost, that is, the manufacturing equipment is expensive, and when the coating thickness is increased, enormous power and time consumption are followed.

On the other hand, when titanium dioxide is thinned on a support by a sol-gel method or the like, the contact area for contaminants and the like to contact the photocatalyst thin film is limited, which takes a long time to decompose and treat the contaminants. In order to effectively remove environmental pollutants using photocatalysts, it is necessary to increase the surface area of photocatalysts or to increase the intensity of light sources. Especially, in air conditioner filters such as air cleaners and air conditioners to remove odorous substances, the processing time Since it requires about 10 ^-3 seconds, the development of a coating sol having high adsorption power and photocatalytic activity is urgently required.

Conventionally, two different types of sol are physically mixed (US Pat. No. 5,591,380) to uniformly disperse different types of particles among different types of particles in a solution state, or two kinds of alkoxides as starting materials ( A method of preparing a sol by simultaneously dissolving alkoxide in a solvent (US Pat. No. 4,176,089) and the like have been disclosed. However, in general, when the two types of sol is mixed, the stability of the sol is reduced and gelled within a short time, and the coating layer becomes thick during coating, and there is a concern that it may detach from the carrier after heat treatment. In addition, when dissolving the sol particles by dissolving the starting material at the same time, there is a disadvantage that the process is complicated because the manufacturing conditions must be precisely controlled.

Accordingly, the present inventors have completed the present invention by developing a photocatalyst coating sol having excellent adsorptive power and photocatalytic activity after continuously studying in view of the problems of the prior art described above.

The present invention provides a highly adsorptive photocatalyst coating sol having a high photocatalytic activity and preventing the decontamination of secondary pollutants caused by the instant photocatalytic reaction, and a preparation method thereof.

The present invention also provides a method for decomposing and removing environmental pollutants, harmful microorganisms, etc. by coating the photocatalyst coating sol of the present invention with a spray method, a dip method, or the like for water treatment and air treatment filters.

1 is a graph showing the photocatalytic activity of a metal mesh coated with a sol for photocatalyst coating without addition of an inorganic adsorbent and a metal mixture;

2 is a graph showing the photocatalytic activity of a metal mesh coated with a photocatalyst coating sol of Example 6 according to the present invention;

3 is a graph showing the photocatalytic activity of a metal mesh coated with a photocatalyst coating sol of Example 7 according to the present invention;

4 is a graph showing an antimicrobial experiment of a metal mesh coated with a photocatalyst coating sol and an inorganic adsorbent and a metal mesh coated with a sol for photocatalyst coating without addition of metal ions according to the present invention;

5 is a graph showing a decolorization experiment of a polyethylene filter coated with a photocatalyst coating sol according to the present invention;

6 is a graph showing an activity test of a polyethylene filter coated with a sol for photocatalyst coating according to the present invention;

7 is a graph showing a saturation activity test of the polyethylene filter coated with a photocatalyst coating sol according to the present invention,

8 is an electron micrograph showing the surface of the polyethylene filter coated with a sol for photocatalyst coating according to the present invention,

9 is an electron micrograph showing a cross section of a polyethylene filter coated with a photocatalyst coating sol according to the present invention.

The photocatalyst coating sol of the present invention is characterized in that it comprises 0.1 to 20% by weight of the photocatalyst, 0.1 to 10% by weight of the inorganic adsorbent, 1 to 20% by weight of the inorganic binder and 55 to 95% by weight of the organic solvent.

In addition, the photocatalyst coating sol of the present invention is 0.1 to 20% by weight photocatalyst, 0.1 to 10% by weight inorganic adsorbent, 1 to 20% by weight inorganic binder, 55 to 95% by weight organic solvent and 0.1 to 10% by weight It characterized by containing a metal compound of.

In addition, the present invention is 1000 to 1500 rpm at room temperature for 10 to 30 minutes after mixing 1 to 20% by weight of the inorganic binder, 55 to 95% by weight of an organic solvent and 0.1 to 0.5% by weight of a strong acid or strong base, if necessary Stirred, and added 0.1 to 20% by weight of the photocatalyst powder and 0.1 to 10% by weight of the inorganic adsorbent, followed by sonication in an ultrasonic apparatus for 10 to 50 minutes, and 0.1 to 10% by weight of the mixture, if necessary. It characterized in that it comprises the addition of a metal compound.

The photocatalyst is generally a photoactive metal oxide, that is, TiO ₂ , ZnO ₂ , ZnO, CaTiO, WO ₃ , SnO ₂ , MoO ₃ , Fe ₂ O ₃ , InP, GaAs, BaTiO ₃ , KNbO ₃ , Fe ₂ O ₃ , And Ta ₂ O ₅ may be used alone or in combination of two or more, and it is particularly preferable to use TiO ₂ and / or ZnO. In addition, the smaller the particle size of the photocatalyst, the better the photocatalyst characteristics, so that the average diameter of the particles is preferably 1 to 50 nm, preferably 1 to 10 nm.

On the other hand, the reaction rate of the photocatalyst is increased by adding a metal or metal oxide, for example, palladium, platinum, radium, tungsten, gold, silver and copper, etc., the additive is 0.01 per total photocatalyst weight -5 weight% can be added and used. In addition, durability can be improved by mixing a hindered amine light stabilizer and a triazole ultraviolet light absorber for the purpose of suppressing deterioration of the photocatalyst coating film due to the photocatalytic action.

The inorganic adsorbent according to the present invention may be used as long as it is a highly adsorbent inorganic substance capable of adsorbing odorous substances and harmful substances in the photocatalytic reaction, and especially silicates, talc, diatomaceous earth, silver and / or containing magnesium or calcium. Or it is preferable to use the zeolite which carried the copper ion.

The inorganic binder according to the present invention may be an isoproposide compound, a silane compound, or the like, and particularly, an isoproposide compound such as titanium isoproposide is preferably used. In this case, a small amount of an acid or a base catalyst may be added to control the hydrolysis rate of the inorganic binder.

As the organic solvent according to the present invention, an alcohol having a lower alkyl group may be used, and in particular, it is preferable to use anhydrous ethanol or isopropanol.

On the other hand, the metal compound according to the present invention can improve the antimicrobial function, and may be used as long as the material is a color when irradiated with a light source, especially a copper compound, for example, acetylacetonate (Copper (II) acetylacetonate), copper acetate hydrate (Copper (II) acetate monohydrate), silver compounds such as silver acetate (Silver Acetate), bengala, vermilion, cadmium red, ocher, cadmium yellow, emerald rock, chromium oxide, Prussian blue, cobalt blue, manganese or carbon black may be used alone or in combination of two or more, and particularly preferably a copper compound.

Referring to the manufacturing method of the photocatalyst coating sol comprising the above configuration as follows.

First, an inorganic binder of 1 to 20% by weight, 55 to 95% by weight of an organic solvent and 0.1 to 0.5% by weight of a strong acid or strong base are mixed as necessary, followed by stirring at 1000 to 1500 rpm at room temperature for 10 to 30 minutes. And 0.1-20 weight% photocatalyst powder is added.

0.1 to 10% by weight of an inorganic adsorbent is added to the mixture, followed by sonication for 10 to 50 minutes in an ultrasonic apparatus to obtain a coating sol of the present invention. In this case, when the inorganic adsorbent decomposes harmful substances such as odorous substances into the photocatalyst, the adsorbent is instantly adsorbed onto the photocatalyst coating film, and the secondary pollutants are adsorbed onto the coating film after the photocatalytic decomposition of the firstly decomposed material. This reduces the likelihood of release into the atmosphere.

In addition, in order to improve the antimicrobial activity of the photocatalyst coating sol according to the present invention or to give a color to the coating film when irradiating UV light on the coating film, 0.1 to 10% by weight of a metal compound may be added as necessary. Is preferably 0.2 to 5% by weight.

Since the photocatalyst coating sol according to the present invention can uniformly disperse different kinds of oxides in the coating film, it can be easily and economically achieved the desired purpose compared to the conventional method. On the other hand, a small amount of acid or base catalyst may be added to control the hydrolysis rate of the inorganic binder.

As a method of supporting the photocatalyst coating sol according to the present invention on a desired substrate, a method of coating and drying by a printing method, a spray method, a dipping method, etc. may be used, but it is recommended to use a spray method and a immersion method. It is good. Here, although the drying temperature of the said spraying method and the immersion method changes with kinds of solvent, generally 50-200 degreeC, especially 100-150 degreeC is preferable.

The term "substrate" may be any one that can be used by coating a photocatalyst coating sol prepared according to the present invention. For example, filters, metals, alloys, glass, curtains, wallpaper, wrapping papers, plastics, and papers, which are required for various carriers requiring various effects such as antibacterial, deodorization, pollution prevention, and various water treatment and air pollution prevention facilities.

When coating the photocatalyst coating sol on the substrate it is necessary to adjust the thickness of the coating film according to the application. Particularly, if the thickness of the coating film is 0.1 μm or more, the photocatalyst layer may be firmly adhered to the substrate to form a highly durable photocatalyst coating structure. As the thickness of the coating film increases, the photocatalytic activity also increases, but the thickness thereof is 5 μm or more. In this case, since the light source cannot sufficiently transmit to the base of the photocatalytic layer, the activity of the photocatalyst no longer increases. On the other hand, it is preferable to have a high photocatalytic activity at 5 μm or less and have a transparent photocatalyst coating film in view of light transmittance. In addition, it is effective to increase the thickness of the coating film to 20 to 50㎛ in order to improve the adsorptive power of the contaminants. Therefore, it is good to manufacture the thickness of a photocatalyst layer to 5-50 micrometers according to a use.

Photocatalyst coating sol according to the present invention is a variety of carriers that require antibacterial, deodorant, pollution prevention, such as interior products such as curtains, wallpaper, daily necessities such as tents, umbrellas, tablecloths, food packaging materials It can be used for agricultural fields such as packaging containers, seedling sheets and the like. As the metal including the photocatalytic function, various alloys such as stainless steel, pearl, brass, aluminum alloy, titanium alloy and the like can be used as the base material in addition to a single metal such as aluminum, iron and copper.

On the other hand, according to the shape and material of the metal to be used, the coating film for photocatalyst coating which concerns on this invention can be formed in the metal sheet | seats, board | plates which were coated with the normal paint, and the colored copper plate which were colored. At this time, if the light transmittance of the adhesive layer and the photocatalyst coating film is high and transparent, the application of the coating material may be improved since the color tone of the base paint is not impaired.

The photocatalytic substrate structure according to the present invention is applied to the window glass of automobiles or various transportation devices, the window glass of buildings, the freezing / refrigerating show cases or the filters of environmental purification systems by utilizing pollution prevention, antibacterial, and deodorizing functions to decompose and disinfect harmful substances. And deodorization is possible at the same time and can improve the antifouling function of the glass surface. In particular, plastic filters used in environmental purification systems, air conditioners and air purifiers, for example, can be used by coating the polyethylene filter, polypropylene filter and the like.

Hereinafter, the present invention will be described in detail through examples. However, the following examples are only for illustrating the present invention in detail and do not limit the scope of the present invention by the examples.

<Example 1>

5 wt% of titanium isopropoxide [Junsei Chemical Co., Ltd.], 78.8 wt% of anhydrous ethanol and 0.2 wt% of hydrochloric acid were mixed, followed by stirring at 1200 rpm for 20 minutes at room temperature. Then 10% by weight of titanium dioxide powder [Degussa P25, Germany] was added.

After the addition of 6% by weight of talc [DUKSAN PURE CHEMICAL Co., Ltd.] to the mixed solution was sonicated for 30 minutes or more in an ultrasonic apparatus [BRANSON Ultrasonic Co., DHA-1000] to prepare a coating sol.

<Example 2>

5 wt% of titanium isopropoxide [Junsei Chemical Co., Ltd], 78.5 wt% of anhydrous ethanol and 0.2 wt% of hydrochloric acid were mixed, followed by stirring at 1200 rpm for 20 minutes at room temperature. Then 10% by weight of titanium dioxide powder [Degussa P25, Germany] was added.

After adding 6% by weight of talc [DUKSAN PURE CHEMICAL Co., Ltd.] to the mixed solution and sonicating for 30 minutes or more in an ultrasonic apparatus [BRANSON Ultrasonic Co., DHA-1000] 0.3% by weight of copper acetate Hydrates [Junsei chemical. Co., Ltd., Japan] to prepare a coating sol.

<Example 3>

A coating sol was prepared in the same manner as in Example 1, but using 5% by weight of diatomaceous earth [DUKSAN PURE CHEMICAL Co., Ltd.] instead of 6% by weight of talc.

<Example 4>

The same method as in Example 2, except that 0.3% by weight of silver acetate instead of 0.3% by weight of copper acetate hydrate [Junsei Chem. Co., Ltd., Japan] to prepare a sol for coating.

Example 5

After mixing 3% by weight of titanium dioxide [Degussa P25, Germany], 93% by weight of ethanol, 0.2% by weight of hydrochloric acid and stirred at 1200rpm at room temperature for 20 minutes.

3.8% by weight of magnesium silicate [Aldrich, USA] was added to the solution, followed by sonication for 30 minutes in an ultrasonic apparatus [BRANSON Ultrasonic Co., DHA-1000] and 0.3% by weight of copper acetylacetonate [Junsei Chem. Co., Ltd., Japan] to prepare a coating sol.

<Example 6>

The coating sol prepared according to Example 1 was coated on a metal mesh [Al Sarong 4x8mm, 0.4T, Brother Metallas, Korea] at room temperature by spray method (1.5 diameter, pressure: 4KG) and then heated to 120 to 150 ° C. Drying to obtain a metal mesh coated with a photocatalyst.

<Example 7>

It was carried out in the same manner as in Example 6, but instead of the coating sol prepared by Example 1, a coating sol prepared by Example 2 was used.

<Example 8>

It was carried out in the same manner as in Example 6, but instead of the coating sol prepared by Example 1, a coating sol prepared by Example 3 was used.

Example 9

It was carried out in the same manner as in Example 6, but instead of the coating sol prepared by Example 1, the coating sol prepared by Example 4 was used.

<Example 10>

The coating sol prepared according to Example 5 was coated on a polyethylene filter [SW80M, Shinwoo, Korea] at room temperature with a spray method [1.5 diameter, pressure: 4KG] and dried at a temperature of 60 ° C. to obtain a photocatalyst coated polyethylene filter. Obtained.

Comparative Example

5 wt% of titanium isopropoxide [Junsei Chemical Co., Ltd.], 95 wt% of anhydrous ethanol, and 0.2 wt% of hydrochloric acid were mixed, followed by stirring at 1200 rpm for 20 minutes at room temperature. Then, 10 wt% of titanium dioxide powder [Degussa P25, Germany] was added and sonicated for 30 minutes or more in an ultrasonic apparatus [BRANSON Ultrasonic Co., DHA-1000] to prepare a coating sol.

Then, the coating sol is coated on a metal mesh [Al Sarong 4x8mm, 0.4T, Brother Metallas, Korea] at room temperature by spray method (1.5 diameter, pressure: 4KG) and dried at 60 ° C. to form an inorganic adsorbent and a metal. A metal mesh without a compound was obtained.

<Experiment>

실험) Experiment using metal mesh

Saturation Activity Test

After preparing a plurality of batch reactors, the metal catalyst coated metal mesh prepared according to Examples 6 to 9 and Comparative Example was placed in each batch reactor, and then trichloroethylene (C ₂ HCl ₃ , TCE) was added. The rate of decomposition was measured by adding. At this time, the initial concentration of trichloroethylene is about 2000ppm, the reactor volume is 125cm ³ , a black light lamp (wavelength 300 to 368nm, maximum wavelength 400nm) to emit ultraviolet light to give photoactivity to the metal mesh [4W BLB, Sankyo denki, Japan] was irradiated with light on the metal mesh, and the decomposition rate of trichloroethylene was measured by a FTIR spectrometer [Perkin Elmer, Spectrum one FT-IR spectrometer].

The results are shown in Figs.

1 shows the activity of a metal mesh coated with a photocatalyst coating sol not adding an inorganic adsorbent and a metal compound according to the comparative example, and FIG. 2 is a photocatalyst coating sol of Example 6 according to the present invention. It shows the activity of the metal mesh, Figure 3 shows the activity of the metal mesh coated with the photocatalyst coating sol of Example 7 according to the present invention.

As shown in FIG. 1, trichloroethylene was decomposed within a few minutes (10 to 20 minutes) when the photocatalyst was decomposed using trichloroethylene (TCE) as a reactant, but a peak of the intermediate product Hosgen was detected (C- Cl: 856 cm ⁻¹ , C═O: 1825 cm ⁻¹ ). This means that the photocatalyst coating sol decomposes trichloroethylene, which is a particular organic matter, but has a disadvantage in that harmful hosgene is released into the air.

Therefore, the photocatalyst coating sol without the inorganic adsorbent and the metal compound is not suitable for use as a photocatalyst filter for an air conditioner or an air cleaner.

In contrast, as shown in Figures 2 and 3, compared with the metal mesh according to the comparative example, the photocatalytic activity was reduced by about 1/2, but after the decomposition of trichloroethylene secondary contaminants (by-products) Was not detected. This is because secondary pollutants were not adsorbed and released into the air by the added superadsorbent inorganic material.

Antimicrobial testing

Two petri dishes with a diameter of 100 mm and a height of 15 mm in which E. coli was cultured and two metal meshes prepared in Example 8 according to the present invention were prepared with two specimens having a size of 3 cm × 6 cm. Then, each of the specimens was placed in a respective container containing the E. coli, and one of them contained a black light lamp [4W BLB, Sankyo Denki, Japan] having a wavelength of 300 to 368 nm, a maximum wavelength of 400 nm, and 4 W from the specimen. It was installed at a distance of 5 cm and irradiated with ultraviolet rays, and another container was not irradiated with ultraviolet rays. At this time, the colony number of the initial E. coli used in the experiment was 70 in each container.

The result is shown in FIG.

As shown in FIG. 4, when exposed to ultraviolet rays for 6 hours, E. coli was completely removed from the container. In addition, the experiment was performed under the same conditions without irradiation of UV light, indicating that the colony count of E. coli was not reduced.

Ii) experiment with polyethylene filter

Decolorization test

0.8 ppm methylene blue aqueous solution (M.B.) [Methylene blue 2-3 hydrate, Junsei Chem. In order to test the adsorption power of the photocatalyst coating sol coated polyethylene filter prepared in Example 10. Co., Ltd, Japan] 25 ml of a 100 mm diameter and 15 mm high petri dish, and the photocatalyst coated polyethylene filter prepared in Example 10 was immersed in the petri dish and spaced 13 cm from the petri dish. The light was irradiated with a black light lamp [4W BLB, Sankyo Denki, Japan] having a wavelength of 300 to 368 nm, a maximum wavelength of 400 nm, and 4 W to test the degree of decolorization of the aqueous solution.

The result is shown in FIG. As shown in FIG. 5, the aqueous methylene blue (M.B.) solution showed a removal rate of 84.4% after 30 minutes.

Deodorization Experiment

To test the odor removal test in the gas phase, a polyethylene filter coated with a photocatalyst prepared in Example 10 was installed in a sealed SUS reactor having a volume of 125 L at the center thereof, and 8 ppm of trimethylamine TMA) was injected into the reactor at a flow rate of 0.83 m / s. After the trimethylamine (TMA) was injected, the removal rate was measured over time, and the results are shown in FIG. 6.

As shown in FIG. 6, the removal rate of trimethylamine after 10 minutes was 82.2%, and 90.41% after 30 minutes.

Saturation Activity Experiment

After installing a polyethylene filter and a circulating fan coated with a photocatalyst coating sol prepared in Example 10 in a sealed SUS reactor having a volume of 125 L therein, 20 ppm of trimethylamine (TMA) as a malodorous substance was added to the reactor. Injected into. Then, the circulation fan was rotated at a speed of 0.83 m / s to circulate the internal air, and left for about 1 hour. Then, the concentration of trimethylamine (TMA) in the reactor was measured. Here, the experiment process is one cycle, and after the cycle is finished, the polyethylene filter coated with the photocatalyst is irradiated with a black light lamp [4W BLB, Sankyo Denki, Japan] for about 1 hour, and then The same experiment was performed. At this time, the cycle was repeatedly performed with the second experiment as 2 cycles.

The result is shown in FIG.

As shown in FIG. 7, trimethylamine removal performance was 1002.7 ppm in total for 53 cycles, and the removal efficiency of trimethylamine (TMA) was maintained at about 90%.

Antimicrobial test

The antimicrobial activity of the polyethylene filter coated with a photocatalyst coating sol prepared in Example 10 was measured using the Shake Flask Method.

Here, the shake flask method is performed by the following method.

First, inoculate test pieces (30 pieces in 1cm X 1cm square) and control pieces (30 pieces in 1cm X 1cm square) with known bacteria, and shake the inoculation solution with a certain amount of neutralizing solution to extract the cultured bacteria. When the number of bacteria present in the neutralization solution is measured, the bacterial reduction rate between the antimicrobial test piece and the control piece is measured by Equation 1 below.

In this case, the neutralizing solution was used as a phosphate buffer (pH 7.0 ± 0.2), the surfactant Tween 80 (0.05%), the number of bacteria in the test solution was shaken at 150 times / min for 24 hours at a temperature of 35 ± 1 ℃ It was measured after incubation.

Known strains used in the Shake Flask Method were Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 25992.

The results are shown in Table 1.

As can be seen from Table 1, the bacterial growth rate of Example 7 and Example 10 using the polyethylene filter coated with a photocatalyst coating sol was hardly seen, and the polyethylene filter (blank) was not coated with a photocatalyst coating sol. The bacterial growth rate was found to be 30 to 40%.

Strain Staphylococcus aureus ATCC 6538 Staphylococcus aureus ATCC 6538 Escherichia coli ATCC 25992 Escherichia coli ATCC 25992 Sample blank Example 7 blank Example 10 Right after vaccination 1.8 × 10 ⁵ 1.8 × 10 ⁵ 1.7 × 10 ⁵ 1.7 × 10 ⁵ 24 hours after vaccination 1.7 × 10 ⁵ <100 1.7 × 10 ⁵ <100 % Of bacteria reduction - 99.9 - 99.9 Rate of increase (rate) 33.9 - 37.1 -

A deficiency test

The antimicrobial of the polyethylene filter coated with a photocatalyst coating sol prepared in Example 10 was measured using ASTM G-21 test criteria.

Known strains used in the ASTM G-21 test criteria were Aspergillus niger ATCC 9642, Penicillium pinophilium ATCC 11797, Chaetomium globosum ATCC 6205, Gliocladium virens ATCC 9645 and Aureobaidium pullulans ATCC 15233.

As a result, a rating of 0 was obtained based on the ASTM G-21 test criteria. Here, the 0 grade means that the known strain did not grow.

On the other hand, the surface and the cross-section of the polyethylene filter prepared in Example 10 is shown by the electron micrograph of FIGS.

As shown in FIGS. 8 and 9, the coating surface of the photocatalyst coating sol was very porous, and the coating thickness was about 20 μm.

As described above, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention should be construed that all changes or modifications derived from the meaning and scope of the appended claims and their equivalents, rather than the detailed description, are included in the scope of the present invention.

As described above, the present invention provides a photocatalyst coating sol that exhibits high adsorption and photocatalytic activity by using an inorganic adsorbent, such as meshes such as metals such as stainless steel, nonferrous metals such as aluminum, nonwoven fabrics, ceramic filters, and polyethylene filters. Filters used in environmental pollutant treatment systems can be coated at room temperature by spraying, dipping, etc. and applied to environmental purification systems.

Claims (11)

A photocatalyst coating sol comprising 0.1 to 20 wt% photocatalyst, 0.1 to 10 wt% inorganic adsorbent, 1 to 20 wt% inorganic binder, and 55 to 95 wt% organic solvent. The method of claim 1, Photocatalyst coating sol characterized in that it further comprises 0.1 to 10% by weight of the metal compound. The method of claim 2, The metal compound is any one selected from copper, silver, bengal, vermilion, cadmium red, ocher, cadmium yellow, emerald rock, chromium oxide, prussian blue, cobalt blue, manganese or carbon black. Sol. The method of claim 1, The photocatalyst is selected from TiO ₂ , ZnO ₂ , ZnO, CaTiO, WO ₃ , SnO ₂ , MoO ₃ , Fe ₂ O ₃ , InP, GaAs, BaTiO ₃ , KNbO ₃ , Fe ₂ O ₃ or Ta ₂ O ₅ Sol for photocatalyst coating. The method of claim 4, wherein The photocatalyst coating sol of Claim 5 whose average diameter of the particle | grains of a photocatalyst is 5-50 nm. The method of claim 1, Inorganic adsorbent sol for photocatalyst coating, characterized in that the silicate, talc, diatomaceous earth or silver and / or copper ion supported zeolite synthesized with magnesium or calcium. The method of claim 1, Inorganic binder is a photocatalyst coating sol, characterized in that the isoproposide compound or silane compound. The method of claim 1, The organic solvent is a photocatalyst coating sol, characterized in that the alcohol having a lower alkyl group. 1 to 20% by weight of an inorganic binder, 55 to 95% by weight of an organic solvent and 0.1 to 0.5% by weight of a strong acid or strong base, if necessary, and then stirred at 1000 to 1500 rpm at room temperature for 10 to 30 minutes, 0.1-20 wt% of the photocatalyst powder and 0.1-10 wt% of the inorganic adsorbent are added to the mixture, followed by sonication for 10 to 50 minutes in an ultrasonic apparatus, and 0.1-10 wt% of the metal compound as necessary. Method for producing a photocatalyst coating sol, characterized in that. A substrate obtained by coating and drying the photocatalyst coating sol according to any one of claims 1 to 8 by printing, spraying, or dipping. The method of claim 10, A substrate, characterized in that the substrate is an aluminum filter, polyethylene filter or polypropylene filter.