KR20040098680A - A metal panel coated with a photocatalyst containing titanium dioxide and a preparation method thereof - Google Patents

Abstract

PURPOSE: Provided are a metal panel which is coated with a titanium dioxide, can be cured at a room temperature by just drying and has a self-cleaning property, a deodorizing effect, an air purifying property and an antibacterial effect and its preparation method. CONSTITUTION: The metal panel is coated with a neutral transparent room temperature curing titanium dioxide coating solution, and the coating solution comprises 1-5 wt% of titanium dioxide nanoparticle dispersed; 0.1 wt% or more of a stabilizer selected from the group consisting of an organic acid having an alcohol group and a ketone group, an organic acid having an alcohol group and an acetate group, their salts and their mixture; a basic solution in such amount capable of neutralizing the stabilizer; and the balance of water or an alcohol as a solvent. Preferably the metal is aluminium, steel or stainless steel.

Description

A metal panel coated with a photocatalyst containing titanium dioxide and a preparation method

The present invention relates to a metal panel coated with titanium dioxide photocatalyst and a method for producing the same, which can be used as a functional building interior and exterior material having self-cleaning, deodorization, air purification and antibacterial action.

Panels made of metals such as aluminum, steel and stainless steel have been commonly used as interior and exterior building materials.

When a metal panel is used as a building exterior material, the surface contamination is severe due to automobile fumes or floating dust, etc., but the cleaning work should be performed periodically. The surface of the building exterior material may be damaged by the abrasives used to clean the contaminants, and the contamination may be further exacerbated, thereby greatly damaging the aesthetics of the building. When a metal panel is used as a building interior material, not only the surface is contaminated by dust, etc., but also bacteria, mold, mites, etc. are proliferating to act as a harmful element to human respiratory diseases and hygiene.

In order to overcome this problem, a metal panel coated with a photocatalyst such as titanium dioxide has been recently developed, but the titanium dioxide coating liquid used must be heat-treated at a high temperature of 100 ° C. or higher, or titanium dioxide dispersed in the coating liquid. Since the particles are not homogeneous, there is a problem in that the transparency of the coating layer formed on the metal panel after coating is poor. In addition, since the pH of the conventional titanium dioxide coating solution is strongly acidic, the work such as coating process is very harmful to the operator.

The inventors of the present invention continued to solve the problems of the conventional titanium dioxide coated metal panel and its manufacturing method, the neutral transparent room temperature curing type titanium dioxide coating liquid is coated to prevent contamination, deodorization, air purification and antibacterial action It came to invent the metal panel which has.

An object of the present invention is to provide a metal panel having a neutral transparent room temperature-curable titanium dioxide coating liquid is coated with anti-fouling, deodorization, air purification and antibacterial action.

Another object of the present invention is a method of producing a metal panel having a transparent titanium dioxide coating layer, having a pollution prevention, deodorization, air purification and antibacterial action,

It is to provide a manufacturing method comprising applying a neutral transparent room temperature-curable titanium dioxide coating liquid to a metal panel to form a coating layer, and curing the coating layer formed by drying at room temperature.

1 is a photograph showing the antimicrobial test results of the aluminum panel according to the present invention for Staphylococcus aureus .

Figure 2 is a photograph showing the antimicrobial test results of the aluminum panel according to the present invention for Escherichia coli ATCC.

According to one aspect of the present invention, a neutral transparent room temperature-curable titanium dioxide coating liquid is coated to provide a metal panel having antifouling, deodorization, air purification and antibacterial activity.

Neutral transparent room temperature curing type titanium dioxide coating liquid used in the present invention

Titanium dioxide in the form of nanoparticulates is dispersed in 1 to 5% by weight, at least 0.1% by weight of a stabilizer selected from an organic acid having an alcohol group and a ketone group, an organic acid having an alcohol group and an acetate group, and salts thereof or mixtures thereof A basic solution in an amount capable of neutralizing the agent, and the remainder is water or alcohol which is a solvent.

The alcohol is a C ₁ -C ₄ lower alcohol such as methanol, ethanol, propanol, isopropanol, butanol.

The stabilizer is preferably glycolic acid and glycolic acid salts, organic acids having a structure similar to glycolic acid and salts thereof, oxalic acid and oxalic acid salts, or mixtures thereof. In addition, the stabilizer may further include pentindiol, alkylacetoacetate, polyethylene glycol, cetyltrimethylammonium hydroxide, polyvinylacetate, polyvinyl alcohol, trialkylalcohol amine ((RO) ₃ N) or mixtures thereof. It may include.

Examples of the basic solution include caustic soda, basic compounds of alkali metals, ammonia, basic compounds of alkylammonium compounds, alkaline earth metal basic compounds, and polyvalent cationic basic compounds such as aluminum ions.

The titanium dioxide coating liquid further includes silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide, iron oxide, or a mixture thereof in the form of nanoparticles to be 50 wt% or less based on the titanium dioxide content. can do. When the organosilicon oxide is further included, the adhesion of the coating liquid to the metal panel is further improved.

The method for preparing a neutral transparent room temperature-curable titanium dioxide coating liquid for use in the present invention is described in detail in the specification of Patent Application No. 2003-21092 filed by the present inventors.

In summary, depending on the solvent used,

A) 1 to 50% by weight of a titanium compound and an organic acid having an alcohol group and a ketone group, a step of sequentially adding at least 0.1% by weight of a stabilizer selected from an alcohol group and an organic acid having an alcohol group, and salts thereof to react by dissolving;

B) slowly adding the reacted solution to distilled water with stirring and stirring for 1 hour or more;

C) adding a basic solution to the resulting solution to neutralize the pH to a range of 6-8; And

D) heating the solution at a temperature of 85 ° C. or higher for at least 7 hours to produce a clear and transparent colloidal solution in which titanium dioxide fine particles having anatase structure and a uniform size of less than 10 nm are dispersed.

In the step A), the titanium compound and the stabilizer may be any one of the first method for producing a neutral and transparent, aqueous titanium dioxide coating liquid, characterized in that

a) 50 to 90% by weight of a titanium compound, an organic acid having an alcohol group and a ketone group, an organic acid having an alcohol group and an acetate group, and 0.1% by weight or more of a stabilizer selected from these salts are added sequentially, followed by stirring for 1 hour or more. Making a step;

b) neutralizing the pH to a range of 6-8 by adding a basic solution to the resulting solution; And

c) heating the solution at a temperature of 75 ° C. or higher for at least 7 hours to produce a clear and transparent colloidal solution in which titanium dioxide fine particles having anatase structure and a uniform size of less than 10 nm are dispersed;

In step a), the titanium compound and the stabilizer may be classified into a method for preparing a neutral and transparent, alcohol-based titanium dioxide coating liquid, characterized in that any one may be added first.

Titanium dioxide compounds preferably used in the above methods include titanium (IV) isopropoxide (tetraisopropanol titanium), titanium (IV) butoxide, titanium (IV) ethoxide (titanium tetraethanolate) and titanium (IV). Methoxide, titanium (IV) styrate, or mixtures thereof. The titanium dioxide compound is added in the form of nanoparticles in the form of nanoparticles in a concentration of 1 to 5% by weight.

If necessary, an organosilicon compound, an aluminum compound, a zirconium compound, an iron compound or a mixture thereof can be added and reacted with the titanium dioxide compound. The organosilicon compound and the like are added in such a ratio that the ratio of TiO ₂ : SiO ₂ and the like dispersed in the resulting colloidal solution is 2: 1 or less.

Further details regarding the method for preparing the titanium dioxide coating liquid, for example, the conditions at each step, the preparation example, and the characteristics of the prepared coating liquid can be easily understood by those skilled in the art with reference to the specification of Patent Application No. 2003-21092. In the present specification, only one preparation example of each of the aqueous and alcoholic titanium dioxide coating solution will be illustrated in the following examples.

According to still another aspect of the present invention, there is provided a method for producing a metal panel having a transparent titanium dioxide coating layer and having antifouling, deodorization, air purification and antibacterial activity.

Provided is a method of forming a coating layer by applying a neutral transparent room temperature-curable titanium dioxide coating liquid to a metal panel, and curing the coating layer formed by drying at room temperature.

The application process is usually performed using a spray method. It is preferable that the thickness of a coating layer shall be 1.0 micrometer or less. When the thickness exceeds 1.0 μm, a coating film is formed to easily peel off the coating layer.

The metal panel of the present invention and the metal panel produced by the manufacturing method of the present invention has a superhydrophilic titanium dioxide coating layer, and has a self-cleaning effect, which naturally removes contaminants when it rains, and only water can be used for cleaning. Do. In addition, the titanium dioxide in the coating layer is in the form of fine particles having a uniform size of less than 10nm, not only the coating layer is transparent, but also the surface area of the photocatalyst becomes wide, so as to efficiently deodorize, air purify, antibacterial action and anti-pollution effect in a short time. Can be performed.

Example

Preparation Example 1 Preparation of Aqueous Coating Solution

175 g tetraisopropanol titanium and 5 g of TEOS (TetraEthoxySilane) were dissolved in 100 mL ethanol, and 5 mL of 40% titanium tetrachloride aqueous solution was added to the hydrolysis reaction with gentle stirring. After 2 mL of pentindiol and 6 g of glycolic acid were added to the resulting solution, the mixture was sufficiently reacted. Then, the solution was slowly added to 750 mL of distilled water with vigorous stirring, and stirring was continued at room temperature for about 1 hour after complete addition. The solution of 3M caustic soda was slowly added to the solution to adjust the pH of the solution to 7. The solution was heated at 85 ° C. for 7 hours to produce a clear and clear titanium dioxide colloidal solution in which titanium dioxide nanoparticles having an anatase structure (10 nm or less) were dispersed.

Preparation Example 2 Preparation of Alcohol-Based Coating Solution

2 mL of pentindiol and 6 g of glycolic acid were dissolved in 800 mL ethanol, and then 175 g of tetraisopropanol titanium and 5 g of TEOS (TetraEthoxySilane) were added thereto. While stirring this solution, 10 mL of 40% titanium tetrachloride aqueous solution was added, and the hydrolysis reaction was performed. At this time, a very vigorous exothermic reaction proceeds, and the reaction is performed until the exotherm stops with sufficient stirring. Then, slowly adding 3M aqueous solution of caustic soda to adjust the pH of the solution to 7, and then heating at a temperature of 75 ° C. or higher for about 7 hours to produce clear transparent titanium dioxide in which titanium dioxide nanoparticles having an anatase structure (10 nm or less) were dispersed. A colloidal solution was produced.

Preparation Example 3 Preparation of Titanium Dioxide Coated Aluminum Panel

The titanium dioxide colloidal solution prepared in Preparation Example 1 was sprayed with a 1.3 mm multi-hole vortex nozzle, and was 0.5 to 1 m distance from an aluminum panel (KAM PPIN PAINT WORKS LTD.) Under a compressor pressure of ⁴ kg / cm ² . After spraying once or twice to form a titanium dioxide coating layer on the surface, it was dried for 2 hours or more at room temperature.

Example 1: Antibacterial Test

The antimicrobial activity of the titanium dioxide coated aluminum panel prepared in Preparation Example 3 was commissioned by KATRI (Korea Apparel Testing & Research Institute) and tested according to AATCC TM147. . The bacteria used in this test were Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922).

As can be seen in the photos of Figures 1 and 2, the aluminum panel according to the present invention had excellent antibacterial action.

Example 2: Deodorization Test

The deodorizing action of the titanium dioxide coated aluminum panel prepared in Preparation Example 3 was carried out for ammonia (NH ₃ ) gas by the gas detection tube method, the results are shown in Table 1.

Table 1

Test period Deodorization rate (%) After 30 minutes After 60 minutes After 90 minutes After 120 minutes 99.699.699.899.8

As can be seen in Table 1, the aluminum panel according to the present invention had an excellent deodorizing action.

The titanium dioxide coated metal panel according to the present invention can be used as a multifunctional building interior and exterior material which can perform self-cleaning, deodorization, air purification, antibacterial action and anti-pollution action because of its transparency and excellent photocatalytic activity. In addition, the manufacturing method of the titanium dioxide coated metal panel according to the present invention is very simple because the coating liquid used is neutral and the working environment is excellent and the curing is performed at room temperature, and only the drying is performed without heat treatment.

Claims (7)

Titanium dioxide in the form of nanoparticles is dispersed at 1 to 5% by weight; 0.1 wt% or more of a stabilizer selected from organic acids having alcohol groups and ketone groups, organic acids having alcohol groups and acetate groups, and salts thereof or mixtures thereof; Basic solution in an amount capable of neutralizing the stabilizer; And the remainder is coated with a neutral transparent room temperature-curable titanium dioxide coating liquid containing water or alcohol as a solvent, the metal panel having anti-fouling, deodorization, air purification and antibacterial action. The method of claim 1, wherein the titanium dioxide coating liquid further comprises a silicon oxide, aluminum oxide, zirconium oxide, iron oxide or a mixture thereof in the form of nanoparticles to be 50% by weight or less based on the titanium dioxide content. Metal paneling. The method of claim 1 or 2, wherein the stabilizer is glycolic acid and glycolic acid salts, organic acids having a structure similar to glycolic acid and salts thereof, oxalic acid and oxalic acid salts, or a mixture thereof Metal panels. The method of claim 1 or 2, wherein the stabilizing agent further comprises pentinediol, alkyl acetoacetate, polyethylene glycol, cetyltrimethylammonium hydroxide, polyvinyl acetate, polyvinyl alcohol, trialkyl alcohol amine ((RO ₃ N) or a mixture thereof. The metal panel of claim 1 or 2, wherein the metal is aluminum, steel, or stainless steel. In the method of manufacturing a metal panel having a transparent titanium dioxide coating layer, has a pollution prevention, deodorization, air purification and antibacterial action, Titanium dioxide coating liquid is applied to the metal panel to form a coating layer, and dried at room temperature to cure the coating layer formed, The titanium dioxide coating solution is dispersed in 1 to 5% by weight of the nanoparticles of titanium dioxide, 0.1 weight of stabilizer selected from an organic acid having an alcohol group and a ketone group, an organic acid having an alcohol group and an acetate group and salts thereof or mixtures thereof. At least%, a basic solution in an amount capable of neutralizing the stabilizer, and the remainder comprising water or an alcohol as the remainder. 7. The method according to claim 6, wherein the coating is performed by a spray method, and the coating layer is formed to have a thickness of 1.0 mu m or less.