JP3634630B2 - Anti-fogging road reflector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anti-fogging road reflector installed at a point of poor visibility such as an intersection.
[0002]
[Prior art]
In general, a reflector is installed at a corner of a road or in a place where visibility is poor to ensure the safety of vehicle travel and pedestrian traffic. However, the conventional reflecting mirror tends to condense on the mirror surface due to the temperature difference between the outside air temperature and the mirror surface, particularly at night or in cold weather, and thus the mirror surface may become cloudy and the function as the reflecting mirror may be reduced. Further, not only the condensation but also the function as a reflecting mirror may be deteriorated not only by the cloudiness caused by the adhering of contaminants such as dust and vehicle exhaust gas to the mirror surface.
[0003]
[Problems to be solved by the invention]
Condensation as one of the causes of the mirror surface fogging as described above occurs when the temperature of the mirror surface is lower than the dew point of the surrounding air, so a heating element is attached to the back side of the mirror surface, and the heating element is connected to a commercial power source or A reflecting mirror has been proposed in which the mirror surface is heated by generating heat with a power supply device such as a solar cell, thereby preventing fogging due to dew condensation. The structure is complicated and expensive, and the installation work is difficult, and the heating element and the power supply device have a long life. Therefore, it is necessary to perform maintenance such as replacement and repair every predetermined period. Moreover, in such a reflecting mirror, there is no solution for fogging caused by contaminants such as dust and vehicle exhaust gas adhering to the mirror surface.
[0004]
Therefore, the present invention solves the above-described problems, and is anti-fogging capable of preventing specular fogging due to condensation and adhesion of contaminants such as dust and vehicle exhaust gas over a long period of time without performing maintenance. It is intended to provide a road reflector.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured as follows.
That is, in the anti-fogging road reflector according to the present invention, a siliceous ceramic layer made of polysilazane or a modified product thereof is directly formed on a mirror surface of a mirror body made of a convex mirror with a thickness of 0.02 to 5 μm. a photocatalyst-containing layer on the siliceous ceramic layer with which is formed directly by, the photocatalyst-containing layer is formed on the front surface, the contact angle of the surface with water is hydrophilic to 0-20 degrees with the photocatalyst-containing layer Thus, the moisture adhering to the surface is uniformly diffused on the surface and the surface is prevented from dew condensation .
[0006]
According to the present invention, since the photocatalyst containing layer containing a photocatalyst such as titanium dioxide is formed on the outer surface of the mirror surface, the surface is hydrophilized by the photocatalyst, it is difficult for condensation to occur, and dust, vehicle exhaust gas, etc. Contaminants are less likely to adhere. That is, photocatalysts such as titanium dioxide are activated by irradiating with ultraviolet rays to express a strong oxidizing power and the surface thereof is hydrophilized, and even if contaminants such as dust and vehicle exhaust gas adhere to the surface, Contaminants are decomposed by strong oxidizing power, and the hydrophilic surface makes it difficult for water to adhere to the surface because water enters between the surface and the surface of the contaminant to adhere to the surface. Since it is easily washed away and removed by rainfall or the like, contaminants are less likely to accumulate. Furthermore, even if the conditions for causing dew condensation are satisfied, moisture adhering to the surface is uniformly diffused to the surface by the hydrophilic surface, so that dew condensation is difficult.
[0007]
In the present invention, a siliceous ceramic layer made of polysilazane or a modified product thereof is formed between the mirror surface and the photocatalyst containing layer on the outer surface. Photocatalysts such as titanium dioxide have strong oxidizing power as described above, so when a synthetic resin plate such as polycarbonate or acrylic is used for the mirror surface, the mirror surface is also oxidized and decomposed, impairing its durability. It is. In addition, when a stainless steel plate is used for the mirror body, sufficient adhesion that can withstand outdoor use cannot be obtained, and when glass is used for the mirror body, the sodium component contained in the glass and titanium dioxide used for the photocatalyst It reacts and becomes sodium titanate, so that the catalytic activity is lost. Therefore, the durability can be improved by forming a silicone-based film between the photocatalyst-containing layer and the mirror surface. This silicone-based film can be obtained by polymerizing a hydrolyzate of alkoxysilane by a conventional sol-gel method. However, this method is difficult to form a dense film and is porous, so the mirror surface is prevented from the oxidative decomposition action of the photocatalyst. Silicone formed by this sol-gel method is not sufficient for protection, and the reflective performance of the mirror surface may be impaired. Further, sufficient heat resistance, bending resistance, wear resistance, etc. cannot be obtained. With respect to the coating film of the system, sufficient adhesion is not obtained when a stainless steel plate is used for the mirror surface. On the other hand, in the present invention, the siliceous ceramic film made of polysilazane or a modified product thereof formed between the photocatalyst containing layer and the mirror surface is a very dense film, and has heat resistance, flex resistance, and wear resistance. It is excellent even in a thin film and has a high coating film hardness.
[0008]
Therefore, according to the present invention, as described above, the siliceous ceramic layer made of polysilazane or a modified product thereof is a very dense film. Therefore, even in a thin film, the mirror body is made of polycarbonate or acrylic due to the oxidative decomposition action of the photocatalyst. When a synthetic resin plate is used, or when glass is used for the mirror surface, the mirror surface is protected, and when a stainless steel plate is used for the mirror surface, sufficient adhesion to withstand outdoor use is obtained. In addition, since it is excellent in heat resistance, no cracks are generated even when the photocatalyst-containing layer is fired, and since it is excellent in bending resistance, no cracks are generated even if it is bent. Since it is excellent in durability and has a high film hardness even in a thin film, the mirror surface is hardly damaged.
[0009]
The material of the mirror body in the present invention is not particularly limited, and may be glass, but in general, a synthetic resin plate such as polycarbonate or acrylic or a stainless plate that is light and inexpensive and has a low risk of breakage is used. Is preferred.
[0010]
The polysilazane in the present invention is not particularly limited, but preferably has at least a Si—H bond or an N—H bond in the molecule, and may be a polysilazane alone or a polysilazane and another polymer. It may be a copolymer or a mixture of polysilazane and other compounds, and polysilazane may be a chain, or may have a cyclic or cross-linked structure, and further have these multiple structures in the molecule at the same time. However, these may be used alone or in a mixture.
[0011]
The film thickness of the siliceous ceramic layer made of this polysilazane or its modified product is preferably 0.02 to 5 μm, preferably 0.05 to 2 μm, and if it exceeds 5 μm, the polysilazane has been converted into a siliceous ceramic layer. Sometimes cracks occur. In order to form this siliceous ceramic layer, a coating film-forming composition comprising polysilazane or a modified product thereof is applied to the mirror surface by an appropriate method such as spray coating, dip coating, spin coating, flow coating, roll coating, etc. What is necessary is just to convert into a quality ceramic layer. The application may be performed once or two or more times.
[0012]
In addition, after apply | coating the said coating-film formation composition, in order to convert this coating film into a siliceous ceramic layer, you may carry out by heating at high temperature and baking, but a mirror surface body is polycarbonate, an acryl, etc. In the case of forming from a synthetic resin plate, there is a limit to the heating temperature, and the following method that can convert to a siliceous ceramic layer at a low temperature where deformation and deterioration of the synthetic resin plate do not occur as much as possible is preferable.
[0013]
That is, it is formed from a film-forming composition in which amines or / and acids are added to polysilazane or a modified product thereof, or a coating film in which amines or / and acids are added to polysilazane or a modified product thereof. If the forming composition is formed by bringing it into contact with water vapor, it can be fired at a low temperature of about 70 degrees, and can be converted into a siliceous ceramic layer at a high speed.
[0014]
To form a photocatalyst-containing layer containing a photocatalyst such as titanium dioxide on the outer surface, a thermal spraying method in which a powder such as titanium dioxide is melted and sprayed, or a CVD (chemical film-forming method) in which titanium dioxide is deposited through a chemical reaction In addition, it may be formed by a suitable method such as a sputter vapor deposition method in which titanium dioxide or the like is deposited by sputtering evaporation, a vacuum vapor deposition method, etc., but titanium dioxide or the like is dispersed in a binder to form a coating composition, which is dipped or sprayed, Application by a flow coater or the like is preferable because a uniform and smooth film is formed.
[0015]
When the photocatalyst-containing layer is formed by such a method, it is preferable to use a silicone compound as the binder. By using a silicone-based compound, the resulting photocatalyst-containing layer has a high surface hardness and is less likely to be scratched, and is also deteriorated by activated titanium dioxide, etc. due to excellent chemical resistance and stain resistance due to siloxane bonds. It is hard to be polluted, and it becomes difficult to adhere pollutants.
[0016]
When a photocatalyst-containing layer is formed using a silicone compound as a binder, for example, a coating composition comprising a mixture of a hydrolyzate of alkoxysilane such as organopolysiloxane or tetraethoxysilane and titania sol is applied. It can be formed by heating at 50 to 200 degrees.
[0017]
Titanium dioxide as a photocatalyst may be a rutile type, but is preferably anatase type because of its high activity, and is activated by irradiating the titanium dioxide with ultraviolet light having a wavelength region of 300 to 400 nm. As a result, the strong oxidizing power is expressed and the contaminants adhering to the surface are decomposed, and the surface is hydrophilized to about 0 to 20 degrees in contact angle with water by the activation, and the hydrophilization contaminates the surface. Substances do not adhere easily, and even if they adhere, they can be easily washed away by rain or the like.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be specifically described with reference to the drawings.
That is, FIG. 1 shows an embodiment of the present invention, (A) is a front view, (B) is a side view, and FIG. 2 is a cross-sectional view of the main part.
[0019]
The form in the drawing is composed of a column 1 erected at an intersection or the like of a road and a reflecting mirror 2 supported by the column 1.
[0020]
In this embodiment, the reflecting mirror 2 is provided with a mirror body 23 in which a surface made of a synthetic resin plate such as polycarbonate or acrylic, a stainless steel plate, glass, or the like is a mirror surface 22 in a frame body 21. Is provided with a ridge 24, but its form is not particularly limited. On the mirror surface 22 of the mirror body 23, a siliceous ceramic layer 25 made of polysilazane or a modified product thereof is formed, and a photocatalyst containing layer 26 containing a photocatalyst such as titanium dioxide is formed on the outer surface thereof. The siliceous ceramic layer 25 is directly formed on the mirror surface 22, and the photocatalyst containing layer 26 is directly formed on the siliceous ceramic layer 25.
[0021]
By irradiating the photocatalyst-containing layer 26 with ultraviolet rays, the photocatalyst is activated and its surface is made hydrophilic, so that contaminants adhering to the surface due to rainfall and the like are washed and condensation is prevented. The photocatalyst containing layer 26 is preferably formed as thin as possible so as not to impair the reflection performance of the mirror surface 22.
[0022]
The ultraviolet ray that activates the photocatalyst may be installed outdoors such as on the road and received from sunlight, but when it is installed outdoors in the factory etc. after being irradiated with ultraviolet rays by black light etc. The photocatalyst may be activated to make the surface of the photocatalyst containing layer 26 hydrophilic.
[0023]
【Example】
Examples of the present invention will be described below.
[0024]
(Example 1)
A mirror surface having a mirror surface was made of stainless steel, and the following coating agent was applied to the mirror surface. Perhydropolysilazane was dissolved in decahydronaphthalene and adjusted to a concentration of 20 wt%. While stirring, 10 mg of this solution was gradually added with 200 mg of tri-n-pentylamine at room temperature. This was coated with a flow coat on the mirror surface in the atmosphere. This was heated in a constant temperature and humidity chamber at 100 ° C. and 90% RH for 1 hour to obtain a siliceous ceramic layer. The film thickness of this siliceous ceramic layer was 0.5 μm.
[0025]
Next, 56 parts by weight of anatase-type titanium oxide sol (Nissan Chemical, TA-15, solid content 15 wt%) and 33 parts by weight of silica sol (Nippon Synthetic Rubber, Glasca A solution, solid content 20 wt%) were mixed, and then methyltrimethoxy 11 parts by weight of silane (Nippon Synthetic Rubber, Glassca B solution) and ethanol were added, and the mixture was further stirred for 2 hours to adjust methyltrimethoxysilane partially by hydrolysis reaction and dehydration condensation polymerization reaction. A photocatalyst containing layer was formed on the siliceous ceramic layer by flow coating.
[0026]
Next, the surface of the obtained sample was irradiated with ultraviolet rays at an illuminance of 1.5 mw per square centimeter for 48 hours using a black light blue fluorescent lamp. Thereafter, when the contact angle of the surface with water was measured, it was 5 degrees or less on average.
[0027]
(Example 2)
The mirror body is made of acrylic and made of this acrylic in the same manner as in Example 1 except that it is heated for 3 hours in a constant temperature and humidity chamber at 80 ° C. and 90% RH when converted into a siliceous ceramic layer. A siliceous ceramic layer is formed on the mirror surface of the mirror body, a photocatalyst containing layer is formed thereon, and then the surface of the obtained sample is illuminated with a black light blue fluorescent lamp at an intensity of 1.5 mw per square centimeter For 48 hours. Thereafter, when the contact angle of the surface with water was measured, it was 5 degrees or less on average.
[0028]
(Example 3)
Except that the mirror body was made of glass, a siliceous ceramic layer was formed on the mirror surface of the mirror body made of glass, and a photocatalyst-containing layer was formed thereon, and then obtained in the same manner as in Example 1. The surface of each sample was irradiated with ultraviolet rays at an illuminance of 1.5 mw per square centimeter for 48 hours using a black light blue fluorescent lamp. Thereafter, when the contact angle of the surface with water was measured, it was 5 degrees or less on average.
[0029]
(Comparative Example 1)
A mirror surface having a mirror surface was made of stainless steel, and the following coating agent was applied to the mirror surface. After mixing 3 parts by weight of silica sol (Nippon Synthetic Rubber, Glassca A solution, solid content 20 wt%), 1 part by weight of methyltrimethoxysilane (Nippon Synthetic Rubber, Glassca B solution) and ethanol are added and stirred for another 2 hours. Methyltrimethoxysilane was partially adjusted by a hydrolysis reaction and a dehydration condensation polymerization reaction. This was applied to the mirror surface by flow coating and heated to obtain a siliceous ceramic layer by a conventional sol-gel method. The film thickness of this siliceous ceramic layer was 1.0 μm.
[0030]
Next, 56 parts by weight of anatase-type titanium oxide sol (Nissan Chemical, TA-15, solid content 15 wt%) and 33 parts by weight of silica sol (Nippon Synthetic Rubber, Glasca A solution, solid content 20 wt%) were mixed, and then methyltrimethoxy 11 parts by weight of silane (Nippon Synthetic Rubber, Glassca B solution) and ethanol were added, and the mixture was further stirred for 2 hours to adjust methyltrimethoxysilane partially by hydrolysis reaction and dehydration condensation polymerization reaction. A photocatalyst containing layer was formed on the siliceous ceramic layer by flow coating.
[0031]
Next, the surface of the obtained sample was irradiated with ultraviolet rays at an illuminance of 1.5 mw per square centimeter for 48 hours using a black light blue fluorescent lamp. Thereafter, when the contact angle of the surface with water was measured, it was 5 degrees or less on average.
[0032]
(Comparative Example 2)
A siliceous ceramic layer formed by the sol-gel method of the prior art is formed on the mirror surface of the mirror body made of acrylic in the same manner as in Comparative Example 1 except that the mirror body is made of acrylic, and a photocatalyst-containing layer is formed thereon. Then, the surface of the obtained sample was irradiated with ultraviolet rays at an illuminance of 1.5 mw per square centimeter for 48 hours using a black light blue fluorescent lamp. Thereafter, when the contact angle of the surface with water was measured, it was 5 degrees or less on average.
[0033]
(Comparative Example 3)
A siliceous ceramic layer by a conventional sol-gel method is formed on the mirror surface of the mirror body made of glass in the same manner as in Comparative Example 1 except that the mirror body is made of glass, and a photocatalyst-containing layer is formed thereon. Then, the surface of the obtained sample was irradiated with ultraviolet rays at an illuminance of 1.5 mw per square centimeter for 48 hours using a black light blue fluorescent lamp. Thereafter, when the contact angle of the surface with water was measured, it was 5 degrees or less on average.
[0034]
The said Examples 1-3 and Comparative Examples 1-3 compared the coating-film performance with the following tests.
[0035]
(Test 1) The sample obtained in the anti-decomposability example for the photocatalyst-containing layer and the sample obtained in the comparative example were irradiated with ultraviolet rays for 240 hours with a super energy irradiation tester (Suga Tester UE-1DEc type). As a result, cracks were observed in the siliceous ceramic layers in Comparative Examples 1 to 3, whereas no abnormality was observed in the siliceous ceramic layers in Examples 1 to 3.
[0036]
(Test 2) Although the sample obtained in the heat resistant example and the sample obtained in the comparative example were heated at 130 degrees for 2 hours, cracks were observed in the siliceous ceramic layers in Comparative Examples 1 to 3. On the other hand, no abnormality was observed in the siliceous ceramic layers in Examples 1 to 3.
[0037]
(Test 3) Flexibility The sunshine weather meter test was conducted in a state where the sample obtained in the example and the sample obtained in the comparative example were curved to a radius of 2000 mm. As a result, in the samples of Comparative Examples 1 to 3, fine cracks were observed on the surface in 100 hours, whereas in Examples 1 to 3, no abnormality was observed after 500 hours.
[0038]
(Test 4) Abrasion resistance A pencil hardness test was performed in order to compare the abrasion resistance of the sample obtained in the example and the sample obtained in the comparative example. As a result, the samples of Comparative Examples 1 to 3 had pencil hardness F to H, while Examples 1 to 3 had 2H to 3H.
[0039]
From the above, since the siliceous ceramic layer made of polysilazane or its modified product is a very dense film, it has excellent functions to protect the mirror surface from the decomposition action of the photocatalyst, and has excellent heat resistance, flex resistance, and wear resistance. It is confirmed that this is suitable.
[0040]
【The invention's effect】
According to the present invention, since the photocatalyst containing layer containing a photocatalyst such as titanium dioxide is formed on the outer surface of the mirror surface, the surface is hydrophilized by the photocatalyst, it is difficult for condensation to occur, and dust, vehicle exhaust gas, etc. Contaminants are less likely to adhere. That is, photocatalysts such as titanium dioxide are activated by irradiating with ultraviolet rays to express a strong oxidizing power and the surface thereof is hydrophilized, and even if contaminants such as dust and vehicle exhaust gas adhere to the surface, Contaminants are decomposed by strong oxidizing power, and the hydrophilic surface makes it difficult for water to adhere to the surface because water enters between the surface and the surface of the contaminant to adhere to the surface. Since it is easily washed away and removed by rainfall or the like, contaminants are less likely to accumulate. Furthermore, even if the conditions for causing dew condensation are satisfied, moisture adhering to the surface is uniformly diffused to the surface by the hydrophilic surface, so that dew condensation is difficult.
[0041]
According to the present invention, a siliceous ceramic layer made of polysilazane or a modified product thereof is formed between the mirror surface and the photocatalyst-containing layer. Therefore, even if a thin film uses a synthetic resin plate such as polycarbonate or acrylic for the mirror body or glass is used for the mirror body, the mirror surface is protected from the oxidative decomposition action of the photocatalyst. When a stainless steel plate is used for the body, sufficient adhesion to withstand outdoor use is obtained, and because it is excellent in heat resistance, cracks do not occur even when the photocatalyst-containing layer is fired, and bending resistance Because it has excellent properties, cracks do not occur even when bent, and in this state it has excellent durability, and even a thin film has high coating hardness. To, the mirror surface is difficult to scratches.
[Brief description of the drawings]
FIG. 1 shows an embodiment of the present invention, in which (A) is a front view and (B) is a side view.
FIG. 2 is a cross-sectional view of a main part in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Support | pillar 2 Reflecting mirror 21 Frame 22 Mirror surface 23 Mirror surface 24 庇 25 Siliceous ceramic layer 26 Photocatalyst containing layer

Claims (3)

A siliceous ceramic layer made of polysilazane or a modified product thereof is directly formed on the mirror surface of the convex mirror surface with a thickness of 0.02 to 5 μm, and a photocatalyst-containing layer is formed on the siliceous ceramic layer. is directly formed, is formed photocatalyst-containing layer on the front surface, the light surface by the catalyst-containing layer is hydrophilic contact angle is 0 to 20 degrees with water, with water adhering to the surface is uniformly diffused on the surface An anti-fogging road reflector characterized in that the surface condensation is prevented . The antifogging road reflector according to claim 1, wherein the siliceous ceramic layer is formed from a composition for forming a coating film in which an amine or / and acids are added to polysilazane or a modified product thereof. The siliceous ceramic layer is formed by bringing a composition for forming a coating film in which an amine or / and acids are added to polysilazane or a modified product thereof into contact with water vapor. Cloudy road reflector.

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