KR100740281B1 - A hollow glass spheres coated a mesoporous TiO2 thin film and a preparation method thereof - Google Patents

Abstract

The present invention relates to a glass hollow sphere having a mesoporous titanium dioxide thin film and a method for producing the same, which can be used in functional building interior and exterior materials having self-cleaning, deodorization, air purification and antibacterial action.

Mesoporous, Titanium Dioxide Thin Film, Glass Hollow Sphere

Description

A hollow glass spheres coated a mesoporous TiO2 thin film and a preparation method

1A and 1B show Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 25922 is a photograph showing the antimicrobial test results of the glass hollow sphere according to the present invention.

2 is a photograph showing the shape of a glass hollow sphere.

3 is a view showing self-cleaning (pollution prevention) of the glass hollow sphere of the present invention.

The present invention relates to a glass hollow sphere having a meso-sized porous titanium dioxide thin film which has self-cleaning, deodorization, air purification and antibacterial action and can be used as a functional building interior and exterior material, and a method for manufacturing the same.

Glass hollow sphere is a spherical ceramic mainly composed of hollow aluminum silicate. It has excellent chemical durability, low density, low dielectric constant, thermal insulation, and mechanical strength. It is used in various fields, from safety products and pens. Glass hollow spheres, especially high-refractive reflective glass hollow spheres have the same high refractive index as diamond, and are processed to easily reflect on the object to be reflected. . Among them, the road sign is made of a reflective sheet containing fine glass hollow spheres, and the lanes on the road are also painted with paint containing glass hollow spheres. These glass hollow spheres, when illuminated by the car at night, reflect back in the direction the light reaches, improving the driver's perception.

In addition, glass hollow spheres are also used as interior and exterior materials for building, interior and exterior wall decoration, flooring, ceiling materials, tiles, artificial marble, marble, beamride, glass acrylic, plywood, paint, wallpaper, resin products are used mixed. When the glass hollow sphere is used as a building exterior material, the surface contamination is severe due to soot or floating dust, etc., but the cleaning work must be performed periodically, but in high-rise buildings, such cleaning is difficult and the required cost is enormous. In addition, the surface of the building exterior material is damaged by the abrasives used for cleaning the adhered contaminants, which further intensifies the contamination and thus greatly deteriorates the aesthetics of the building. Therefore, the use of glass hollow spheres coated with titanium dioxide on the surface not only prevents contamination of the surface of the building exterior material with dust, etc., but also prevents bacteria, mold, mites, etc. from using untreated glass hollow spheres. By inhibiting the proliferation of there is an advantage that can inhibit the elements harmful to human respiratory diseases and hygiene.

In order to impart this effect, the present invention has developed a glass hollow sphere having a titanium dioxide mesoporous thin film.

Typically mesoporous membranes have the following characteristics:

1) When the compound is adsorbed in the pupil, the compound adsorbed in the pupil is relatively stabilized by capillary condensation. It can therefore be used as an adsorbent of volatile or nonvolatile organic contaminants;

2) collect and transport physically and chemically labile compounds in the pupil;

3) It can be used as a highly efficient catalyst or carrier for catalyst because its specific surface area is very large, about 700 ~ 900m ² / g;

4) Coating porous titanium dioxide thin film with high refractive index on solar cell to increase the light efficiency of solar cell by scattering light in the pupil.

However, although the mesoporous thin film is excellent in its application as described above, the colloidal solution used for coating the thin film is prepared under strong acidic conditions and thus cannot be used for various purposes. It was difficult to use various types of surfactants to form.

The present inventors continued to solve the problems of the glass hollow sphere having a conventional mesoporous titanium dioxide thin film and a method for manufacturing the same, a neutral colloidal solution for a mesoporous titanium dioxide thin film, a method of manufacturing the same and mesoporous using the same The titanium dioxide thin film was completed and described in detail in patent application 2004-73453 filed by the present inventors.

Since the colloidal solution for mesoporous titanium dioxide thin film of the above application is neutral, it is excellent in its application and has an advantage that it can be applied to a wide range of fields. It is possible to produce a mesoporous thin film having and can be applied to a variety of applications.

An object of the present invention is to provide a glass hollow sphere having a neutral colloidal solution for porous titanium dioxide thin film having a meso-sized pupil is coated with antifouling, deodorizing and antibacterial action.

Another object of the present invention is a method for producing a glass hollow sphere having a transparent porous titanium dioxide thin film, having a pollution prevention, deodorization, air purification and antibacterial action, the neutral for the porous titanium dioxide thin film having a meso sized pupil in the glass hollow sphere It is to provide a manufacturing method comprising applying a colloidal solution to form a coating layer, and curing the coating layer formed by drying at room temperature.

According to one aspect of the present invention, a neutral colloidal solution for porous titanium dioxide thin film having meso sized pores is coated to provide a glass hollow sphere having antifouling, deodorizing, air purification and antibacterial action.

The colloidal solution for porous titanium dioxide thin film having meso-sized pores used in the present invention is neutral, and the titanium dioxide nano fine particles having a size of 2 to 10 nm are dispersed very stably at a high concentration of 5%, and the surfactant is 3 to 30 weight. %, Stabilizer 0.1 to 10% by weight, and the balance is characterized in that it comprises water or alcohol as a solvent. If less than 3% of the surfactant is added, no mesoporosity is formed, and if more than 30% is added, the viscosity of the solution is greatly increased, resulting in uneven formation of the thin film. The concentration of the titanium dioxide nano fine particles and the range of addition of the stabilizer are described in detail in the inventor's patent application 2004-73453.

The alcohol is a lower alcohol of C1 to C4 such as methanol, ethanol, propanol, isopropanol, butanol, and alcohol is added to dissolve the titanium dioxide precursor or used as a solvent, and evaporation is good because it has to be volatile during thin film coating. Use lower alcohol.

In the present invention, the stabilizer is a compound having a ketone, a hydroxyl group, an alcohol group and a compound having an amine or an amide group in the position adjacent to the alcohol group, hydroxyl group, for example, glycolic acid or glycolate, and polyethylene-, Polypropylene-, polybutylene-glycol polymers or oligomers, and monomers may be used.

As surfactant, you may use combining one or more selected from a cation, an anion, a nonionic, and an amphoteric surfactant. When using a combination of cationic and anionic surfactants, it is effective to add one kind in a small amount.

In the present invention, any of the surfactants used as the template of the mesopores may be used, but an ionic surfactant is particularly effective in the polar portion. Phosphates, sulfates, organic acid salts, and the like can be used as the anionic surfactant, but anionic surfactants soluble in water or alcohol can be almost used. Alkyl amine-based surfactants are generally used as the cationic surfactant, for example, cetyltrialkylammonium halide is used. In this case, the larger the carbon number of the alkyl group, the size of the mesopores increases. Nonionic surfactants include polyethylene oxides, polypropylene oxides, polybutylene oxides, or copolymers of these polymers, or organic compounds containing diblock polymers, polyvinyl alcohols, polyethylene glycols, amides or amine groups and organic acids, Surfactants that dissolve in water or alcohol may be used. In particular, since the nonionic surfactant has a high molecular weight and is effective in dispersibility of the titanium dioxide nanocolloid, there is an advantage that it is easy to arbitrarily control the size or shape of the pupil.

Since the colloidal solution for the mesoporous titanium dioxide thin film prepared in the present invention is in a neutral aqueous solution phase, the colloidal solution may be coated using various methods such as a coating method using a spray method, an immersion method, or the like on the surface of a desired molding. After coating the colloidal solution for mesoporous titanium dioxide thin film on the surface of the molding, heat treatment in air at 350 ~ 550 ℃ for 3 hours or more to burn the surfactant contained in the mesopores to form a pure mesoporous titanium dioxide thin film. .

The formation of meso-sized pupils in the colloidal solution for porous titanium dioxide thin film having mesopores of the present invention is as follows:

When surfactant is added to the solvent at the critical micelle concentration, initially, spherical micelles are formed, and gradually increasing concentrations form rod-shaped micelles, which form hexagonal dense structures. The polar portion of the rod micelles and the hydrolyzed metal oxides (titanium dioxide) interact to form the walls of the pupil outside the rod micelles. Therefore, the size and structure of the rod-shaped micelle becomes the size and structure of the mesopores. Since the critical micelle concentration varies depending on the type of the surfactant, the amount of the surfactant added and the method of preparing the solution are referred to Examples.

The mesoporous titanium dioxide thin film prepared according to the method of the present invention is a mesoporous titanium dioxide thin film in which the size and structure of the pupil is very uniform and the walls of the pupil are very stable. The porous titanium dioxide thin film of the present invention has a specific surface area of 700 to 900 m ² / g or more, and exhibits porous thin film characteristics having various pupil structures such as hexagonal cylinder structure or cubic structure. In addition, as a template of mesopores having a size of 1 to 20 nm, all surfactants such as cationic, anionic, nonionic and amphoteric surfactants can be used.

The method for preparing a neutral colloidal solution for porous titanium dioxide thin film having meso-sized pores used in the present invention is described in detail in the specification of Patent Application No. 2004-73453 filed by the present inventors.

In summary, the method for preparing the neutral colloidal solution for porous titanium dioxide thin film having meso-sized pores used in the present invention is as follows:

1) add stabilizer to water and dissolve under stirring;

2) adding a titanium compound to the solution and then hydrolyzing with stirring;

3) dissolve the surfactant in separate water;

4) The surfactant solution and the colloidal solution of the titanium compound are mixed with vigorous stirring to prepare a colloidal solution for porous titanium dioxide thin film having meso-sized pupils.

According to another aspect of the present invention, the colloidal solution for porous titanium dioxide thin film having a neutral meso-sized pupil may be prepared by the following method.

1) add stabilizer and surfactant to water and dissolve under stirring;

2) adding a titanium compound to the solution and then hydrolyzing with stirring;

3) The reaction is continued while heating the solution to prepare a colloidal solution for mesoporous titanium dioxide thin film.

According to another aspect of the present invention, a neutral colloidal solution for porous titanium dioxide thin films having mesopores of neutral, stable and uniform composition is prepared in an organic solvent such as alcohol:

1) Dissolve by adding stabilizer to alcohol.

2) A titanium compound is added to the solution, and distilled water is added.

3) The solution is sufficiently hydrolyzed with stirring for at least 1 hour.

4) The solution is heated to 50 to 70 ° C. for at least 3 hours to prepare a clear and clear titanium dioxide colloidal solution.

5) Separate the solution and dissolve it by adding surfactant to alcohol.

6) The surfactant solution and the titanium dioxide nano colloidal solution are mixed with vigorous stirring to prepare a neutral colloidal solution for porous titanium dioxide thin film having meso-sized pupils.

In the present invention, all organometallic compounds in the form of Ti (OR) ₄ (R = alkyl group), which is an organotitanium type, can be used, and also Ti (X) ₄ (X = halogen element), titanium sulfate, titanium oxide Inorganic titanium compounds such as the like may be used. In this case, instead of titanium tetraisopropoxide, all tetra alkoxy titanium organic compounds of the Ti (OR) ₄ type may be used.

According to yet another aspect of the present invention, there is provided a transparent porous titanium dioxide coating layer, the method of producing a glass hollow sphere having antifouling, deodorization, air purification and antibacterial action,

The method is provided by applying a neutral transparent mesoporous titanium dioxide coating solution to the glass hollow sphere to form a coating layer, and curing the coating layer formed by drying at room temperature.

Glass hollow spheres used in the present invention have a variety of sizes in the range of 5 ~ 150㎛ diameter depending on the application. The glass hollow sphere may be mixed with paint or the like and processed on the object by painting and spraying, or may form a reflecting mirror having a high refractive index to have a reflecting function.

The glass hollow sphere produced by the manufacturing method of the present invention has a superhydrophilic mesoporous titanium dioxide thin film layer as shown in FIG. 3, and has a self-cleaning effect, so that it is easy to clean with water alone. In addition, since the titanium dioxide in the thin film layer is in the form of fine particles having a meso size, not only the thin film layer is transparent but also the surface area of the photocatalyst is widened, so that it is possible to efficiently prevent contamination, deodorization, air purification and antibacterial activity in a short time.

Further details regarding the preparation method of the mesoporous titanium dioxide coating liquid, for example, the conditions at each step, the preparation examples, and the characteristics of the prepared coating liquid can be easily understood by those skilled in the art by referring to the specification of Patent Application No. 2004-73453. The following examples are not intended to limit the present invention as examples of the preparation of the neutral colloidal solution for the aqueous and alcoholic titanium dioxide thin film of the present invention.
As used herein, "%" refers to weight percent, unless otherwise defined.

Example

Production Example  1: Preparation of colloidal solution for aqueous titanium dioxide thin film

20 g of glycolic acid and 7.0 g of triethanolamine were added and dissolved in 650 ml of distillation, and 160 g of titanium tetraisopropoxide was added to the resulting solution and heated to 50 to 70 ° C. Separately from this solution, 150 g of polyethylene-polypropylene oxide diblock polymer, which is a nonionic surfactant, is added to 300 ml of distilled water, and the mixture is sufficiently stirred to dissolve. The surfactant solution and the titanium dioxide nano colloidal solution were mixed with vigorous stirring to prepare a colloidal solution for mesoporous titanium dioxide thin film.

Production Example  2: Preparation of Colloidal Solution for Titanium Dioxide Thin Film in Alcohol Solvent

20 g of glycolic acid and 7.0 g of triethanolamine are added and dissolved in 650 ml of ethanol, and 160 g of titanium tetraisopropoxide is added to the resulting solution, and the mixture is sufficiently stirred. 40 g of water is added to this solution and heated to 50-70 ° C. To 300 ml of this solution and ethanol, 150 g of polyethylene-polypropylene oxide diblock polymer as a nonionic surfactant is added and dissolved with sufficient stirring. The surfactant solution and the titanium dioxide nano colloidal solution were mixed with vigorous stirring to prepare a colloidal solution for mesoporous titanium dioxide thin film.

Production Example  3 :: Preparation of colloidal solution for aqueous titanium dioxide thin film

A colloidal solution for a mesoporous titanium dioxide thin film was prepared by the method of Example 1, except that 150 g of triton-x-100, which is a nonionic surfactant, was added instead of using a polyethylene-polypropylene oxide diblock polymer in Preparation Example 1. It was.

Production Example  4: Preparation of glass hollow sphere coated with mesoporous titanium dioxide thin film

The mesoporous titanium dioxide colloidal solution prepared in Preparation Example 1 was sprayed with a 1.3 mm multi-hole vortex nozzle, and the glass hollow sphere (SPHERICEL ^® , manufactured by Potters Industries Inc.) under a compressor pressure of ⁴ kg / cm ² . After spraying 1 to 2 times at a distance of 0.5 to 1 m to form a mesoporous titanium dioxide thin film layer on the surface, it was dried at room temperature and then heat-treated at a temperature of 350 ~ 550 ℃ for 3 hours.

Example  1: antibacterial test

The antimicrobial activity of the glass hollow spheres having the mesoporous titanium dioxide thin film layer prepared in Preparation Example 4 was commissioned by KATRI (Korea Apparel Testing & Research Institute) and tested in accordance with AATCC TM147, and the photographs of the test results were taken. FIGS. 1A and FIG. Shown in 1b. The bacteria used in this test were Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922). In addition, the antimicrobial results are shown in Table 1.

As can be seen in the photos of Figure 1, the glass hollow sphere according to the present invention had an excellent antibacterial action.

sample Test Bacteria 1 * Test Bacteria 2 ** Average Area of Suppression Area Bacteria Growth on Specimen Average area of the suppression zone Bacteria Growth on Specimen #One 0.0mm No growth 0.0mm No growth

* Test Bacteria 1: Staphylococcus aureus ATCC 6538

** Test Bacteria 2: Escherichia coli ATCC 25922

Example  2: Deodorization Test

The deodorizing action of the glass hollow sphere having the mesoporous titanium dioxide thin film layer prepared in Preparation Example 4 was performed on ammonia (NH ₃ ) gas by a gas detection tube method, and the results are shown in Table 2.

    Test period     Deodorization rate (%)      After 30 minutes After 60 minutes After 90 minutes After 120 minutes       99.6 99.6 99.8 99.8

As can be seen in Table 2, the glass hollow sphere according to the present invention had an excellent deodorizing action.

Example  3: self Cleaning  exam

A test paint was prepared by adding 150 g of a glass hollow sphere having a mesoporous titanium dioxide thin film layer synthesized according to Preparation Example 1 to 1 kg of an aqueous paint. Half of the glass specimens were painted with the test aqueous paint, and the other half were coated with conventional water-based paint without the addition of glass spheres, and the two parts were compared and tested.

As a result of observation after 14 days, it could be observed that the contamination of the part painted with the glass hollow sphere with the mesoporous titanium dioxide thin film layer according to the present invention was reduced. That is, the portion painted with the paint including the glass hollow sphere having the mesoporous titanium dioxide thin film layer according to the present invention was cleaned and cleaned of the contaminants due to the self-cleaning effect compared to the portion painted with the test aqueous paint.

The mesoporous titanium dioxide coated glass hollow sphere according to the present invention can be used as a multifunctional building interior and exterior material that can perform self-cleaning, deodorization, air purification, antibacterial action and anti-pollution action due to its transparent and excellent photocatalytic activity. . In addition, the manufacturing method of the titanium dioxide-coated glass hollow sphere according to the present invention is very simple because the coating liquid used is neutral and the working environment is excellent and it is cured at room temperature. .

Claims (5)

Glass hollow sphere with pollution prevention, deodorization, air purification and antibacterial action, Neutral and 2-10 nm sized titanium dioxide nanoparticles are dispersed very stably at a high concentration of 5% by weight, 3-30% by weight of surfactant, 0.1-10% by weight of stabilizer and the remainder of water or alcohol as a solvent. It has a thin film layer is coated with a colloidal solution comprising, the thin film layer is very uniform in size and structure of the pupil, the wall of the pupil is very stable, the specific surface area is 700 ~ 900m ² / g, the stabilizer is glycolic acid Glass hollow spheres selected from glycolate and polyethylene-, propylene-, butylene-glycol polymers or oligomers or monomers. The method of claim 1, wherein the surfactant is anionic surfactant such as phosphate, sulfate, organic acid salt, cationic surfactant such as cetyltrialkylammonium halide salt, polyethylene oxide, polypropylene oxide, polybutylene oxide, or these A glass hollow sphere selected from a copolymer of a polymer or a non-ionic surfactant such as a diblock polymer, polyvinyl alcohol, polyethylene glycol, an amide or an organic compound containing an amine group and an organic acid. In the manufacturing method of glass hollow sphere having mesoporous titanium dioxide thin film layer and having anti-fouling, deodorization, air purification and antibacterial action, Applying a colloidal solution for the mesoporous titanium dioxide thin film to the glass hollow sphere, and dried at room temperature, and heat-treated at 350 ~ 550 ℃ in air, for at least 3 hours, The titanium dioxide nano colloidal solution for forming the porous titanium dioxide thin film is neutral and dispersed very stably in a high concentration of 5% by weight of titanium dioxide nanoparticles of 2 ~ 10nm size, surfactant 3 ~ 30% by weight, stabilizer 0.1 ˜10% by weight and remainder as water or alcohol as solvent, The stabilizer is selected from glycolic acid or glycolate and polyethylene-, propylene-, butylene-glycol polymers or oligomers or monomers. 4. The surfactant according to claim 3, wherein the surfactant is anionic surfactant such as phosphate, sulfate, organic acid salt, cationic surfactant such as cetyltrialkylammonium halide salt, polyethylene oxide, polypropylene oxide, polybutylene oxide, or these And a nonionic surfactant such as a copolymer of a polymer or a diblock polymer, polyvinyl alcohol, polyethylene glycol, an amide or an organic compound containing an amine group and an organic acid. The method according to claim 3 or 4, wherein the coating is performed by a spray method, and the thickness of the coating layer is formed to be 1.0 mu m or less.

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