JP2000234070A - Ambient temperature setting super water-proof photocatalyst paint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a super water-proof anti-bacteria and anti-pollution paint for protecting surface of a thing. SOLUTION: This paint is prepared by compounding an ethyl silicate and a silane coupling agent to a mixed alcohol solution carrying a dispersed photocatalyst, titanium dioxide and silicon dioxide, and combining an isopropyl alcohol in which a polyalkyl siloxane compsn. and a methylmethoxy siloxane are dissolved to the former solution. An example of compounding contains 1-10% titanium dioxide, 2-3% silicon dioxide, 10-15% ethanol, 55% isopropyl alcohol, 2-5% methanol, 3-5% ethyl silicate, 3-5% silane coupling agent, 0.3-0.7% polyalkyl siloxane compsn., 3-5% methylmethoxy siloxane, and 2-4% toluene. In this method, hardness of coating, strength of photocatalyst reaction, and hydrophobic property are freely changed by changing the compounding ratios of ethyl silicate, titanium dioxide, the polyalkyl siloxane, and the methylmethoxy siloxane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a super-waterproof antibacterial and antifouling paint for protecting the surface of an object.

[0002]

2. Description of the Related Art Products produced by burning photocatalytic titanium oxide on glass, tiles and steel plates at high temperatures have been developed, but methods for processing materials having no heat resistance and objects that cannot be burned at high temperatures such as buildings, ships, and vehicles have been developed. It has not been. A drawback of the conventional cold-curable photocatalytic coating is that it has no water resistance and, when exposed to water for a long time, the coating is hydrolyzed and peeled off. When ultraviolet rays of 400 nm or less are applied to the surface to which the photocatalytic paint is applied, a photocatalytic reaction occurs, and hydrophobic molecules on the surface are decomposed together with the organic substances attached to the surface by an oxidation-reduction action, so that a hydrophilic coating film is formed. Since the hydrophilic coating film is easily compatible with water and has a large contact area, hydrolysis is easily promoted. If the object coated with the conventional photocatalytic coating material (ST-KO3) is immersed in water for 24 hours or more, hydrolysis of the coating film proceeds and the hardness decreases. When the hardness of the coating film was reduced to a pencil hardness B or less, the coating surface was peeled off only by rubbing with a finger, so that the photocatalytic coating material could not be used in a portion in contact with water.

[0003]

The biggest cause of deterioration of the coating film of the photocatalytic paint of the room temperature curing type is due to hydrolysis. The present invention incorporates a hydrophobic substance into a photocatalytic paint that cures at room temperature,
It is intended to prevent hydrolysis by making the coating film less compatible with water. An object of the present invention is to provide a super-water-resistant hydrophobic photocatalytic coating by fusing a hydrophobic substance without hindering the catalytic reaction and the hard film formation of a cold-curable photocatalytic coating.

[0004]

SUMMARY OF THE INVENTION The present invention provides an isopropyl alcohol obtained by dissolving ethyl silicate, a silane coupling agent, a polyalkylsiloxane composition, and methylmethoxysiloxane in a liquid in which titanium dioxide and silicon dioxide are dispersed and supported in a mixed alcohol. Is blended.
After applying the present invention, they found that the coating film exhibited hydrophobicity and improved water resistance, and made improvements and completed the present invention. Formulation Examples Tatin dioxide 1-10% Silicon dioxide 2-3% Ethanol 10-15% Isopropyl alcohol 55% Methanol 2-5% Ethyl silicate 3-5% Silane coupling agent 3-5% Polyalkylsiloxane composition 0.3 -0.7% Methylmethoxysiloxane 3-5% Toluene 2-4% In the present invention, by changing the mixing ratio of ethyl silicate, titanium dioxide, polyalkylsiloxane and methylmethoxysiloxane, the hardness of the coating film and the strength of the photocatalytic reaction are improved. , The ability to develop hydrophobicity can be freely changed.

[0005]

[Operation] In the present invention, the undiluted solution is applied or sprayed on the surface of the object with a brush or roller and dried at room temperature.

[0006]

EXAMPLES The present invention will be described more specifically with reference to examples, and application examples will be described. Example 1 Water was dropped on a sample obtained by applying the present invention to glass and dried for 24 hours, and the contact angle between the glass surface and the water droplet was measured to be 71 °. After irradiating the sample with sun light for 5 hours, water was dropped, and the contact angle between the glass surface and the water droplet was measured. The result was 68 °. The surface of the object coated with the present invention is hydrophobic and its properties are hardly affected by the photocatalytic reaction. Measuring device: Kyowa contact angle meter CA-A (manufactured by Kyowa Interface Science Co., Ltd.) Measuring method: average value of three points measured Example 2 In Example 1, when water adheres to the coating surface of the present invention, a polka dot is formed. When exposed to light, the hydrophobic molecules adsorbed on the surface are decomposed, and there is no support for the polka dots, so that it becomes unstable.
As a result, the polka dot slides off the surface with a slight inclination or vibration, so that water droplets and dirt do not adhere to the application surface. Example 3 Two sets of samples were prepared by applying the present invention to a 4 cm × 4 cm square plywood and dried for 24 hours, and subjected to a mold resistance test according to JISZ2911 standard. The sample was grounded on an agar medium dispensed into a sterilized petri dish having a diameter of 15 cm, and after inoculating a mixed spore dispersion of mold, the temperature was 24 to 26 ° C. and the humidity was 95 ± 5.
%. One of the samples was shielded from light, and the other was irradiated with light from a fluorescent lamp of 20 watts and cultured for 45 days. As a result, a large amount of mold propagated in a week in the sample cultured in the dark. Fig. 1 Mold does not propagate at all on the sample cultured under light irradiation even after 45 days. Moreover, 1 to 1.5c around the sample
A zone of inhibition is formed in which the inoculated bacteria cannot propagate in a width of m. Free radicals (OH
Antibacterial activity due to radicals) is acting around the sample.
Fig. 2 By making the photocatalytic coating hydrophobic, the antibacterial and antifouling function was not hindered, but it was proved that it worked. Example 4 JIS after coating the present invention on glass and drying for 24 hours
As a result of measuring the pencil hardness of the coating film according to the K5404 standard,
The hardness was 6H. After 2400 hours of immersion of the glass in water, the pencil hardness of the coating film was measured to be 5H, and the hardness was hardly reduced. Further, the coating film is transparent without white turbidity due to hydrolysis. It was proved by the pencil hardness test of the coating film that the water resistance was greatly improved by processing the photocatalytic coating material to be hydrophobic. Example 5 The present invention was applied to a glass having a width of 15 cm and a length of 35 cm and a white boulder, placed in a glass aquarium in which freshwater fish were bred, and allowed to stand for 100 days. Algae adhered to the glass in the aquarium and propagated, but no algae or dirt adhered to the glass and cobblestone coated with the present invention. Fig. 3 The right side width of the glass of 4 cm was not coated with the present invention, and the state of adhesion of algae was compared. The OH radical generated by the photocatalytic reaction spreads in water and exhibits an anti-algal effect. However, since the algae are generated on the glass of the aquarium, the entire aquarium is not affected. Example 6 In Example 5, water was placed in a water tank (30 cm wide × 60 cm long) at a depth of 30 cm, and 5 goldfish, 1 crucian carp, 1 loach
As a result of raising 0 animals for 100 days, there were no abnormalities in the fish and no deaths. The present invention controls the growth of algae, but has no adverse effect on fish. FIG. 4 Example 7 The present invention was applied to a ventilation fan installed in a kitchen, and 100 days have passed. However, oil smoke generated during cooking does not adhere to the application surface. The result is that oil and fat hardly adhere to the hydrophobic coating film, and the dirt slightly adhered is decomposed and eliminated by the photocatalytic reaction. FIG.

[0007]

By applying the present invention to the surface of an object, a hardened film having hydrophobicity and water resistance is formed, and deterioration and damage due to wind and rain are prevented. Furthermore, it prevents water, dirt and microorganisms from adhering and decomposes them to purify the environment.

[Brief description of the drawings]

FIG. 1 shows a sample coated with the present invention subjected to a mold resistance test while shielding light. It is a photograph of one week of culture.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Petri dish 2 Medium 3 Sample which applied this invention to plywood

FIG. 2 is a photograph on the 45th day of culture in which a sample coated with the present invention was irradiated with light to perform a mold resistance test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Petri dish 2 Medium 3 Sample which applied this invention to plywood 4 Inhibition zone which controls the growth of bacteria

FIG. 3 is a photograph of a glass to which the present invention has been applied is put into an aquarium, and after 100 eyes.

[Explanation of symbols]

1. 1. Algae does not adhere to the portion where transparent glass is coated with the present invention (CK-101). No algae generation on unpainted parts

FIG. 4 shows an aquarium containing fish coated with the present invention and a fish (after 100 days)

[Explanation of symbols]

 1. Goldfish in aquarium 2. 2. Glass of aquarium with algae attached Shiraishi ball without algae

FIG. 5 is a photograph 100 days after using the ventilation fan coated with the present invention.

[Explanation of symbols]

 1. 1. Ventilation fan and frame without oil stain Walls with oil stains (unpainted)

Claims (1)

[Claims] 1. A method for adding super-water resistance to a cold-curable photocatalytic paint.