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

Abstract

Disclosed is a photocatalytic coating sol composition and the method for preparing the same. The photocatalityc coating sol composition comprising 0.1% to 20% by weight of a photo-catalyst, 0.1% to 10% by weight of an inorganic adsorbent, 1% to 20% by weight of an inorganic binder, 55% to 95% by weight of an organic solvent and if necessary 0.1% by weight to 10% by weight of a metal compound. Specifically, the present invention can remove harmful substances by coating photocatalytic coating sol composition prepared from photocatalyst, inorganic adsorbent, inorganic binder, metal compound and organic solvent on metal filter such as aluminum etc., and plastic filter such as polyethylene and polypropylene etc. used in environmental contaminants treatment system or air conditioning plant such as air-conditioner and air-cleaner, according to any one of and ordinary coating techniques such as spray method or dipping method etc. at room temperature.

Description

TECHNICAL FIELD [0001] The present invention relates to a photocatalytic coating sol composition and a method for preparing the same, and more particularly to an application to an environmental purifying system in a manner of coating a photocatalytic coating sol composition, having high adsorption property as well as high photocatalytic activity, on meshes of metal such as stainless steel, non-ferrous metal such as aluminum, non-woven fabric, ceramic filter and plastics such as polyethylene (PE) filter, by means of an inorganic binder, by using common coating techniques such as spraying method or dipping method etc. at room temperature. BACKGROUND ART [0002] Previously, the conventional method for treating environmental contaminants could be classified into two methods. One is a physico-chemical method which includes adsorption, cooling condensation, solvent scrubber, catalytic oxidation method. And another is a biological treatment method. However, the adsorption method and the coo...

AI Technical Summary

Benefits of technology

[0016] An object of the present invention is to provide a photocatalytic coating sol composition and method for preparing the same, capable of preventing delamination of secondary contaminants generated by transient photocatalytic reaction and having high photocatalytic activity.

Problems solved by technology

However, the adsorption method and the cooling condensation method are ineffective for fundamentally treating the contaminants, and thus there is a limitation on using these methods.

However, the above methods have several disadvantages, because an additional device is required to spray the chemicals in order to take place the reaction of the chemicals effectively with the contaminants in areas having vast production source of contaminants, and a large amount of chemicals must be used for neutralizing the contaminants in an area having a large amount of contaminants in high concentration.

Meanwhile, both in direct combustion method and the catalytic oxidation method, substances causing pollutions are removed through an oxidation process, which show a high removal rate, yet produce secondary contaminants such as NOx and SOx, and require high cost.

However, the method has technical problems, for example, contaminants used as nutrients for growth of the microorganisms must be continuously administered into a reactor where a substantial contaminants removal is performed, the carrier must be washed periodically, the microorganisms must be well controlled, and process of this method must be operated continuously.

However, if the contaminants are adsorbed on the surface prior to recombination of the electron and the hole, the contaminants are decomposed by the electron and the hole.

However, the method requires complex process steps such as generating photocatalytic particles on the carrier after coating, crystallization of anatase type having high photocatalytic activity, and sintering at the temperature range of 400 to 600° C. to give adherence to a carrier, resulting in high manufacturing cost.

Also, the application of this method is restricted to coat on polymer materials such as plastics having poor heat resistance.

Further, even though a photocatalytic coating on tiles and ceramics having excellent heat-resistance is carried out and then treated at high temperature, there are still problems such as large power consumption.

However, there are also problems such as high initial investment cost due to the manufacturing of equipments, high consumption of electric power and manufacturing time due to the increase of coating film thickness.

Also, if titanium dioxide is formed as a thin-film on a support according to the sol-gel method, it requires much time for decomposing contaminants because of limited contact area of contaminants on the thin-film containing photocatalyst.

However, in case of mixing two kinds of sol composition, the stability of sol composition decreases and turns into gel in short time.

And, the methods have the disadvantage in that the condition of the manufacture process must be controlled accurately when sol particles are dispersed by dissolving start materials simultaneously.

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