KR100577752B1 - A Deodorizing Material comprising a Titanium Dioxide Layer and a layer that contains a Light Absorbing Substrate - Google Patents

Abstract

The present invention relates to a material having a light absorbing material which provides light for photocatalytic activity of titanium dioxide and a titanium dioxide layer which exhibits photocatalytic activity and is used as an air purifier, a water purifier, a building material, a filtration system, , Garbage containers, and the like, for use in applications of base metals.

In the deodorizing material according to the present invention as described above,

A light absorbing substrate for storing the absorbed light and emitting at least a portion of the absorbed light upon reduction or elimination of the light source, and

And a coating film formed on the substrate,

The coating film is capable of decomposing fungi, bacteria and odorous compounds, and the surface region of the coating for receiving light is formed of a metal oxide which exhibits photocatalytic activity upon irradiation with ultraviolet light.

Photocatalytic activity, phosphorescent material, metal oxide layer, titanium dioxide, ultraviolet ray irradiation, phosphorescence

Description

[0001] The present invention relates to a deodorizing material containing a phosphorescent material and a titanium dioxide layer,             

Figure 1 shows a test apparatus used to test the efficacy of the product of the present invention.

The present invention relates to a deodorizing material in which a surface of a metal plate coated with a photocatalytic titanium dioxide layer or a luminous layer absorbing and emitting light is formed together with a nonmetal plate. A plate on which a luminous material layer is formed provides photocatalytic activity, which is formed with a metallic compound layer. This plate has deodorizing, antibiotic activity and anti-pollution properties.

The present invention relates to a surface treatment technique for forming a metal plate or a non-metallic plate having a light absorbing material and a metallic compound layer having photocatalytic activity. In known deodorization methods, equipment or equipment is used to remove or mask odors. The fungus is removed with a chemical agent, which is selected according to the type of fungus.

Odor and mold are caused by microorganisms such as bacteria, yeast and fungi, and animal and plant cells. Thus, as an attempt to prevent and seize mold and pollutants, these cells can be destroyed, i.e., sterilized. Known sterilization methods include heating, irradiation with ultraviolet light or other radiation, cell destruction by ultrasonic waves, electrical sterilization, gas sterilization, and sterilization using chemicals including antibiotics. A sterilization method using fine particles of a photocatalyst is also known. It is known that a photocatalyst such as titanium dioxide exhibits a photocatalytic function by light of a specific wavelength and has deodorizing and antifungal functions through its oxidizing action.

In the prior art, a material such as titanium dioxide, iron oxide, tungsten oxide, silicon oxide or the like, optionally having a secondary metal such as platinum on the surface of the metal in order to improve the catalytic function, is used as a photocatalyst. In order to take advantage of deodorization and antifungal function, the metal is crushed into fine particles to form a fixed coating on the surface of the material, or the fine particles are dispersed in the object to be treated.

Various studies have been carried out on methods of deodorizing and imparting antifungal functions to a material by using a photocatalytic function, but it is difficult to treat particles as a material. The known fixed coatings are only used experimentally and their strength is not sufficient. In addition, since the production of a photocatalyst material as a thin film is difficult industrially, it is not yet in the commercialization stage.

It is an object of the present invention to provide a material having a light absorbing material that provides light for photocatalytic activity of titanium dioxide and a titanium dioxide layer that exhibits photocatalytic activity.

It is another object of the present invention to provide a material exhibiting deodorizing, antibiotic activity and anti-fouling properties in a dark room after a short period of exposure to light.

Another object of the present invention is to provide a process for the preparation of a coating of a titanium dioxide layer coated with a titanium dioxide layer having photocatalytic activity, which can be used in the application of useful base metals such as air purifiers, water purifiers, building materials, filtration systems, food processing equipment and containers, Thereby providing a base material surface.

The present invention having the above object provides a material (metallic or non-metallic material) coated with a metallic compound exhibiting photocatalytic activity together with a light absorbing material. The material to be coated with the metal compound is preferably metal, plastic, composite, paper or the like. Preferably, the metallic compound layer is formed of anatase TiO ₂ .

The photocatalytic activity of the coated material of the present invention is useful in applications where base metal can be usefully used, including air cleaners, water purifiers, building materials, filtration systems, food processing equipment and containers, .

The present invention is characterized in that the photocatalytic activity proceeds at a location where the material is exposed to a limited amount of light. Since the luminous material absorbs and stores the light and emits light in the dark room, the photocatalytic activity in the dark room is very active, while the phosphorescent material emits light. Titanium dioxide can perform deodorizing function, antibiotic activity, and environmental pollution-preventing function in a limited manner even under conditions in which no light is irradiated. Therefore, the luminous material can improve the catalytic activity in places where exposure to light is limited, such as refrigerator, closet, indoor, air and water filtration systems (air purifiers, water purifiers), food processing and storage, Can be used very effectively.

When exposed to a light source, phosphorescent, the phosphorescent material stores the light. In the dark room, the phosphorescent material emits incandescent light. The phosphorescent material used here is a mixture of fluorescent color pigments combined with phosphorescent pigments.

Incandescent light in the dark room serves to convert the absorbed light energy into visible light. The light energy emitted during the excitation state is called fluorescence and the light energy emitted in the dark room is called phosphorescence. To extend the afterglow process, an optical storage material is used. For example, a typical light-storing material widely used in the watch industry is zinc sulfide with added copper. This material has a decay time of 20 minutes and low lightness. It also turns black after prolonged exposure to ultraviolet light or sunlight. To prolong the afterglow time of this material, some manufacturers have added a further radioactive material called promethium. As a result, the material can emit incandescent light for several hours, but it also emits harmful radiation.

Luminous materials emit different colors, ie, green, blue, purple, and the like, and their types vary. However, it has been found that the light source from the fluorescent lamp may be sufficient for effectively expressing the catalytic activity, but ultraviolet irradiation is most effective for the photocatalytic activity of titanium dioxide. For this reason, the preferred phosphorescent material used in the present invention is a material emitting violet (430 nm) very close to ultraviolet wavelength (UVA) 315-400 nm.

The human eye responds to light having a wavelength of about 790 nm (red) to 430 nm (purple). Light with a wavelength shorter than the wavelength visible by the human eye is called ultraviolet light (light deviating out of purple).

Ultraviolet (UV) is included in the wavelength range produced by the sun. Most ultraviolet rays are absorbed by the ozone layer or reflected back into space and only a small amount of light reaches the surface. The sunlight is received by direct light and diffuse light, that is, skylight scattered by the atmosphere. The sky looks blue because air molecules scatter blue light of shorter wavelength than red light. Ultraviolet rays scatter more than blue light. If you look in the ultraviolet light, the sun will look like a hazy circle in a clear sky.

Ultraviolet rays are classified into three wavelength bands. That is, UVA (315-400 nm), UVB (290-315 nm) and UVC (220-290 nm). UVA mainly generates photochemical smog and damages and fades plastics, paints and fabrics. UVC is completely absorbed by ozone and other gases and does not reach the surface. Only 1% of sunlight is contained in the UVB band, and most of the UVB is also absorbed by the ozone.

With reference to Figure 1, which shows a test apparatus used to demonstrate the efficacy of the present product, the sealed container 11 is preferably transparent, which includes a circulation fan 12, a valve for actuation of a gas detector 16 (14) and an ultraviolet light source (15). The plate 13 representing the titanium dioxide and the phosphorescent material is inserted into the test container 11.

The metallic compound used in the present invention is selected from the group of metal compounds which are activated upon light irradiation. For example, a metal oxide such as titanium oxide, iron oxide, silver oxide, copper oxide, aluminum oxide, tungsten oxide, silicon oxide, Zinc oxide, and strontium titanate. [0043] The term " zinc oxide " In addition, metals or other metal oxides that modify metal oxides can be used to promote the photocatalytic reaction. That is, it is possible to further use at least one compound selected from the group consisting of platinum, palladium, gold, silver, copper, nickel, rhodium, niobium, tin, cobalt, ruthenium oxide and nickel oxide. In the amount added to the metal oxide, the metal or metal oxide is preferably used in an amount of 0.01 to 20% by weight based on the metal oxide of the present invention.

Metal oxides can be prepared by a variety of techniques including, but not limited to, high temperature sintering of metals, electrolytic oxidation, chemical vapor deposition, vacuum evaporation, coating, coprecipitation, metal halogenation, evaporation oxidation, neutralization and hydrolysis of inorganic metal salts, A sol-gel method or the like. Commercially available products are also available. Conventional methods such as mixing, precipitation, ion exchange, photoelectron deposition, kneading and the like can be used as a method of modifying the above-mentioned metal or metal oxide.

In the present invention, a method of forming a thin film of a metal oxide on a base material is preferably performed by a method selected from the group consisting of spray coating, dip coating, spin coating, sputtering and the like. It is a method of fixing metal oxide to a floating state.

The light energy based on the irradiation includes a wavelength region corresponding to the excited state of the photocatalytic action. Particularly, it is preferable to use light energy including an ultraviolet wavelength of less than 400 nm, which contributes to the photocatalytic reaction. As a light energy source, it is possible to use not only natural light sources from the sun but also light from a mercury lamp, light from a fluorescent lamp, light from a filament lamp such as a halogen lamp, light from a short-arc xenon lamp, It is possible to use an artificial light source such as a beam. Further, as an auxiliary light source for sunlight, an artificial light source can be used at the same time.

As a method of irradiation, light may be directly irradiated onto the metal oxide film formed on the base material, or, in the case of a phosphorescent material, light may be emitted from the phosphorescent material after the light source is removed to activate the photocatalyst, A method of irradiating the coating film by using the above-mentioned method can be used.

In the present invention, when light is irradiated to a substance having a metal oxide coating film showing catalytic activity on the surface thereof, odor and mold (hereinafter referred to as "unnecessary substance") which adheres to or comes into contact with the surface of the substance on which the film is formed, Is photochemically decomposed and removed through the photocatalytic activity of the film. Thus, unlike the prior art, the present invention does not actually require physical work, large-scale equipment and facilities, and maintenance thereof. Unnecessary substances are economically and simply decomposed and removed. Compared with conventional catalysts such as oxidation catalysts, the metal oxide used as a photocatalyst in the present invention has a slightly reduced activity due to heat deterioration and toxic elements, but has a function of decomposing and removing unnecessary substances, that is, Antifungal properties and the like are maintained for a long time. Further, according to the present invention, a substance having a coating on its surface absorbs ultraviolet rays. The mechanism of decomposition and removal of unnecessary substances proceeding on the metal oxide film showing photocatalytic activity is as follows. That is, as light energy is incident on the metal oxide film by irradiation, active electrons and holes are generated on the surface of the metal oxide. These electrons and holes react directly with unwanted materials or active OH radicals produced by such unwanted materials. This is considered to be a mechanism for removing unnecessary substances.

The present invention relates to a deodorizing material comprising a light absorbing substrate and a film formed on the substrate, the film being capable of decomposing fungi, bacteria and odorous compounds, Is formed of a metal oxide which exhibits photocatalytic activity upon irradiation with ultraviolet light.

The phosphorescent substrate stores absorbed light. Preferably, the phosphorescent substrate releases at least a portion of the absorbed light upon reduction or removal of the light source. The substrate is selected from the group consisting of metals, plastics, composites and paper. Preferably, the substrate emits phosphorescence upon reduction or elimination of the light source.

Preferably, the metal oxide film is made of titanium dioxide. More preferably, the coating is anatase-type titanium dioxide. Preferably, the substrate is coated with a phosphorescent material. When the substrate is a transparent material (e.g., plastic), a phosphorescent material may be coated on the opposite side of the side where the coating is formed. Preferably, the luminous material is a paint or a luminous sheet. Most preferably, the phosphorescence of the substrate is used to activate or increase the photocatalytic activity of the coating.

The photocatalytic property of the present invention is obtained by titanium dioxide which transforms the metal oxide layer into hydroxide ion. Hydroxide ions are effective against microorganisms, bacteria, fungi, etc. due to their strong oxidation potential. The hydroxide ion has a stronger oxidation characteristic than the chloride (Cl ₂ ) or ozone (O ₃ ) commonly used in the sterilization process, and may be effective in decomposing oil or protein. When hydroxide ions come into contact with bacteria, they damage cell walls and bacteria in a short time.

Examples will be described below.

Example 1 (Preparation of starting material)

Polypropylene plate: 10 cm x 20 cm x 1 mm (+/- 0.5 mm) (thickness)

Titanium dioxide (anatase type): 50 mg

Nitrocellulose: 200 mg

(Isopropyl alcohol was sprayed onto the powder before use to prevent the nitrocellulose from exploding)

RuCl ₃ : 5 mg

Methyl ethyl ketone (2-butanone)

- Formation of titanium dioxide coating layer of plastic plate:

1. 100 mg of nitrocellulose was dissolved in 10 mL of methyl ethyl ketone, and the polypropylene plate was immediately sprayed with a methyl ethyl ketone solution or immersed in this solution.

2. The mesh thus formed was dried for 5 minutes.

3. In a separate container, 100 mg of nitrocellulose, 50 mg of titanium dioxide and 5 mg of RuCl ₃ were completely dissolved and mixed with 15 cc of methyl ethyl ketone.

4. One side of the dried plate was sprayed with the above three solutions or immersed in this solution.

Methyl ethyl ketone mostly evaporated and did not remain on the surface. There was thus no problem with organic compounds on the surface. Titanium dioxide decomposes organic compounds on the surface.

Example 2 (Formation of phosphorescent material on the prepared titanium dioxide plate)

10 mL of the phosphorescent paint was sprayed onto the surface of the plate prepared in Example 1, which was not coated with TiO ₂ . The plate was air dried for 30 minutes.

Example 3

A 10 cm x 20 cm luminous sheet was adhered to the surface of the plate prepared in Example 1 not coated with TiO ₂ using a double-sided tape.

Example 4

The plate prepared in Example 3 was placed in a closed plastic container, and the container was exposed to ultraviolet rays (200-400 nm) while the experiment was proceeding. A key xenon lamp was used as the light source.

They were added to 0.5 mL NH ₃ in an airtight plastic container. The results were as follows.

50% NH ₃ was reduced after 60 minutes.

After 90 minutes 80% NH ₃ was reduced.

98% NH ₃ was reduced after 120 minutes.

Example 5

Two plates coated with a TiO ₂ solution in Example 2 were placed in a closed container and exposed to light and NH ₃ according to the procedure of Example 7. [ The results were as follows.

80% NH ₃ was reduced after 60 minutes.

After 90 minutes 98% NH ₃ was reduced.

Example 6

Three plates coated with the TiO ₂ solution of Example 3 were placed in a closed container and exposed to light and NH ₃ according to the procedure of Example 7. [ The results were as follows.

80% NH ₃ was reduced after 10 minutes.

After 30 minutes, 98% NH ₃ was reduced.

According to the present invention, by providing a substance having a titanium dioxide layer exhibiting photocatalytic activity and phosphorescent material that provides light for photocatalytic activity of titanium dioxide, a metal oxide layer exhibiting a photocatalytic activity function is provided on the surface of the phosphorescent material And thus on the opposite side) to provide a property of deodorizing objects or air in contact with the material.

Further, according to the present invention, it is possible to manufacture a material exhibiting deodorization, antibiotic activity and anti-fouling characteristics in the dark room even after a short time exposure to light, and the photocatalytic activity of the coated material of the present invention can be effectively utilized as an air purifier, , Filtration systems, food processing equipment and containers, garbage containers, etc., can be usefully used in applications where base metal can be usefully used.

Claims (10)

A phosphorescent substrate for absorbing and emitting a light source and a deodorizing material coated with a metal oxide film for removing mold odor from the phosphorescent substrate, A phosphorescent material consisting of a mixture of a phosphorescent pigment and a fluorescent color pigments is coated to absorb the absorbed light and to emit a portion of the absorbed light upon reduction or elimination of the light source, A light absorbing susbstrate; A methyl ethyl ketone solution layer formed by spraying a methyl ethyl ketone solution in which nitrocellulose is dissolved on the surface of the phosphorescent substrate; A metal oxide such as titanium oxide, iron oxide, silver oxide, copper oxide, aluminum oxide, tungsten oxide, silicon oxide, zinc oxide zinc oxide, and strontium titanate; a metal oxide film formed by using one compound selected from the group consisting of zinc oxide and strontium titanate; Wherein a methyl ethyl ketone solution layer is applied on top of the phosphorescent substrate and a metal oxide coating is applied on the methyl ethyl ketone solution layer so that the surface region of the coating exhibits photocatalytic activity upon ultraviolet irradiation A deodorant material having a layer of material and a layer of titanium dioxide. delete delete delete The method according to claim 1, The metal- Wherein the titanium dioxide layer is formed of a material layer containing a phosphorescent material characterized by being anatase type titanium dioxide. 6. The method according to claim 1 or 5, The metal- One compound selected from the group consisting of platinum, palladium, gold, silver, copper, nickel, rhodium, niobium, tin, cobalt, ruthenium oxide and nickel oxide is mixed with 100% metal oxide 0.01 to 20% by weight, based on the total weight of the photocatalyst-containing material layer and the titanium dioxide layer. delete delete delete delete

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