JPH10196291A - Tunnel inner wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain water repellency of a tunnel inner wall surface over a long period of time by forming a surface layer containing photocatalyst particles, silicone and a substance to prevent the transformation into a hydrophilic property by light excitation of a photocatalyst, on a base material surface. SOLUTION: In a tunnel 10, an arch-shaped wall 12 is lined with an interior trimming plate 14 covered with a surface layer, and a surface layer containing photocatalyst particles, silicone and substance to prevent the transformation into a hydrophilic property by light excitation of a photocatalyst such as cobalt or a cobalt compound, is formed on a surface of this interior trimming plate 14. Therefore, the transformation of silicone into a hydrophilic property by light excitation of the photocatalyst can be prevented, and a stain sticking with the lapse of time can be decomposed on the basis of oxidizing-decomposing performance of the photocatalyst. Therefore, water repellency of the surface can be maintained, and a tunnel inner wall can maintain a permanently unstainable condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner wall of a tunnel which is hardly contaminated with smoke or the like.

[0002]

2. Description of the Related Art The inner wall of a road tunnel may be formed only by cast-in-place concrete, but recently, in order to improve the environment in the tunnel, particularly the landscape, and to prevent traffic accidents in the tunnel. In many cases, at least painting is performed or the interior is lined with an interior board (lining). As interior panels, asbestos panels, tiles, enameled iron plates, plated iron plates, stainless steel plates, aluminum panels, plastic panels, and the like are used.

[0003]

The inner wall of the tunnel is contaminated with soot in the exhaust gas of automobiles, abrasion powder of tires, and dust soaring from the road surface. In particular, highway tunnels with heavy traffic are heavily soiled. On a highway, the length of a tunnel tends to be long, and if ventilation is insufficient, the tunnel is apt to become dirty. If the inner wall of the tunnel is darkened by smoke, etc., the view of the tunnel will be damaged,
The dark impression can make driving in the tunnel painful or adversely affect the driver's attention. Therefore, it is desirable to clean the inner wall of the tunnel as needed.

Conventionally, the inner wall of a tunnel has been cleaned by brush cleaning. Cleaning the inner wall requires traffic regulation (such as lane restriction), which hinders smooth traffic,
With considerable danger. Therefore, it is difficult to wash it with sufficient frequency. Further, since an interior plate such as an asbestos panel has irregularities on its surface, it is not only easy to stain, but it is impossible to completely remove the stain by brush cleaning.
Some of the adhered dirt remains even after brush cleaning, so that the dirt accumulates as the number of times of cleaning increases.

[0005] As a method for preventing the adhesion of the dirt,
It is known that it is better to impart water repellency to the surface of a substrate. When water repellency is imparted to the surface of the base material, the surface energy is significantly reduced, so that it becomes difficult for dirt components to adhere. As one of the methods, there is a method of forming a surface layer made of a water-repellent silicone on a substrate surface. However, with this structure, the contact angle with water is reduced to about 70 ° due to the adhesion of dirt over time, and the effect of water repellency is not maintained. Therefore, as another method for solving the above-mentioned problem, there is a method of forming a surface layer comprising a photocatalyst and a water-repellent silicone on the surface of a substrate. According to this method, it is possible to decompose the adhered dirt over time based on the oxidative decomposability of the photocatalyst. However, in this configuration, when exposed to sunlight outdoors, the silicone is hydrophilized by photoexcitation of the photocatalyst, so that the water repellency of the surface cannot be maintained. In view of the above circumstances, an object of the present invention is to provide a tunnel inner wall that can maintain the water repellency of the surface for a long period of time, and to provide a tunnel inner wall that is less likely to be contaminated.

[0006]

According to the present invention, in order to solve the above-mentioned problems, photocatalytic particles, water-repellent silicone, and hydrophilicity of the water-repellent silicone by photoexcitation of the photocatalyst are provided on a substrate surface. Or a layer containing photocatalyst particles and a water-repellent silicone is formed on the surface of the base material, and is further formed on at least a part of the surface of the layer. The present invention provides an inner wall of a tunnel, on which a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst is fixed. Preventing the silicon from becoming hydrophilic by photoexcitation of the photocatalyst by making the surface layer contain a substance such as cobalt or a cobalt compound for preventing the photocatalyst from becoming hydrophilic by photoexcitation. Can be. In addition, since the photocatalyst is contained, it is possible to decompose the dirt adhering with time based on the oxidative decomposability of the photocatalyst. Therefore, the water repellency of the surface can be maintained, and the inner wall of the tunnel can be maintained in a permanently hardly soiled state.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG.
0 can be constructed by a well-known method with an arch-type wall 12 made of, for example, cast-in-place concrete. In the embodiment shown, the arch wall 12 is lined with an interior panel 14 coated with a surface layer, whereas the concrete wall 1
2 may be directly coated with a surface layer. In the interior board 14,
As before, asbestos panels, tiles, enameled iron plates, plated iron plates, stainless steel plates, aluminum panels, plastic panels, and the like can be used. As shown in FIG. 2, a surface layer containing photocatalyst particles, silicon, and a substance for preventing photocatalyst such as cobalt or a cobalt compound from becoming hydrophilic by photoexcitation is formed on the surface of the interior plate 14, as shown in FIG. I have. In another embodiment of the present invention, as shown in FIG. 3, a layer containing photocatalyst particles and a water-repellent silicone is formed on the surface of the interior board 14, and at least a part of the surface of the layer is formed on the surface. A substance for preventing hydrophilicity due to photoexcitation of a photocatalyst of a water-repellent silicone such as cobalt or a cobalt compound is fixed.

[0008] The photocatalyst has an energy larger than the energy gap between the conduction band and the valence band of the crystal.
A substance capable of generating conduction electrons and holes by excitation of electrons in the valence band (photoexcitation) when irradiated with light (excitation light) having a short wavelength (excitation light).
Oxides such as zeta-type titanium oxide, zinc oxide, tin oxide, ferric oxide, bismuth trioxide, tungsten trioxide and strontium titanate can be suitably used. As a light source used for photoexcitation of the photocatalyst, illumination 16 in a tunnel such as a high-pressure sodium lamp, a low-pressure sodium lamp, a metal halide lamp, a fluorescent lamp, a mercury lamp, a fluorescent mercury lamp, and a lighting of a passing car such as a headlamp can be used.

The silicone has an average composition formula R _p SiO _{(4-p) / 2} (where R is a functional group comprising one or more monovalent organic groups, or a monovalent organic group). A resin represented by the following formula: X is an alkoxy group or a halogen atom, and p is a number satisfying 0 <p <2. Is available.

As the cobalt compound, a cobalt alloy, cobalt oxide, cobalt chloride, cobalt sulfate, cobalt iodide, cobalt bromide, cobalt acetate, cobalt chlorate, cobalt nitrate and the like can be suitably used.

The thickness of the surface layer is preferably set to 0.4 μm or less. Then, cloudiness due to irregular reflection of light can be prevented, and the surface layer becomes substantially transparent. Further, it is more preferable that the thickness of the surface layer be 0.2 μm or less. Then, it is possible to prevent the surface layer from being colored by light interference. Also, the thinner the surface layer, the better its transparency. Further, when the film thickness is reduced, the wear resistance of the surface layer is improved.

Metals such as Ag, Cu and Zn can be added to the surface layer. The surface layer to which the metal is added can kill bacteria and fungi attached to the surface even in a dark place.

Pt, Pd, Ru, Rh, I
A platinum group metal such as r or Os can be added.
The surface layer to which the metal is added can enhance the redox activity of the photocatalyst, and can improve the decomposability of organic contaminants and the decomposability of harmful gases and odors.

Next, a surface layer containing photocatalyst particles, a water-repellent silicone, and a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst is formed on the surface of the substrate. The method of manufacturing the water-repellent member described above will be described. The production method in this case is basically based on applying a coating composition on the surface of a substrate and curing the coating composition.

Here, the coating composition includes a precursor of silicon as an essential component of a substance for preventing photocatalytic particles such as photocatalyst particles, cobalt or a cobalt compound from becoming hydrophilic by photoexcitation, and water, Solvents such as ethanol and propanol, catalysts that promote hydrolysis of silicone precursors such as hydrochloric acid, nitric acid, sulfuric acid, acetic acid and maleic acid, and basic compounds such as tributylamine and hexylamine Silicon compounds such as acidic compounds such as aluminum, aluminum triisopropoxide and tetraisopropyl titanate;
And a surfactant for improving the dispersibility of the coating liquid such as a silane coupling agent.

As cobalt or a cobalt compound, a water-soluble cobalt compound is preferably used. As the water-soluble cobalt compound, for example, cobalt chloride, cobalt sulfate, cobalt iodide, cobalt bromide, cobalt acetate, cobalt chlorate, cobalt nitrate and the like can be suitably used.

[0017] Here silicone - The precursor emissions in the average composition formula _{R p SiX q O (4-} pq) / 2 ( wherein, R consists of one or more organic groups monovalent functional X or a functional group comprising two or more selected from a monovalent organic group and a hydrogen group, X is an alkoxy group or a halogen atom, and p and q are 0 <p <2, 0 <
a film-forming element composed of a siloxane represented by the following formula: q <4) or a general formula R _p SiX _4-p (where R is one or more monovalent organic groups) Wherein X is an alkoxy group or a halogen atom, and p is 1 or 2. A film-forming element comprising a hydrolyzable silane derivative to be
Can be suitably used.

Here, as the coating film forming element comprising the hydrolyzable silane derivative, methyltrimethoxysilane,
Methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltributoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, Phenyltributoxysilane,
Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldibutoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, phenyl Methyldipropoxysilane, phenylmethyldibutoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltripropoxysilane, n-propyltributoxysilane, γ-glycoxydoxypropyltrimethoxysilane, γ -Acryloxypropyltrimethoxysilane and the like can be suitably used.

The film-forming element composed of the above-mentioned siloxane includes partial hydrolysis and dehydration-condensation polymerization of the above-mentioned hydrolyzable silane derivative, or partially hydrolyzate of the above-mentioned hydrolyzable silane derivative, tetramethoxysilane and tetramethoxysilane. It can be produced by dehydration polycondensation with a partial hydrolyzate such as ethoxysilane, tetrapropoxysilane, tetrabutoxysilane, diethoxydimethoxysilane and the like.

The coating method of the coating composition includes spray coating, dip coating, flow coating, spin coating, roll coating, brush coating, and sponge. A method such as coating can be suitably used. As a curing method, it can be carried out by polymerizing by heat treatment, standing at room temperature, ultraviolet irradiation, or the like.

Next, a layer containing photocatalyst particles and a water-repellent silicone is formed on the surface of the substrate, and at least a part of the surface of the layer has a hydrophilic property due to the photoexcitation of the photocatalyst of the water-repellent silicone. A method for producing a water-repellent member to which a substance for preventing the formation of a water-repellent material is fixed will be described. The production method in this case is basically based on the photo-excitation of a photocatalyst such as cobalt or a cobalt compound after coating and curing a coating composition containing photocatalyst particles and a water-repellent silicone precursor. By applying a solution containing a substance for preventing hydrophilization and fixing the solution to the surface.

Here, the coating composition contains photocatalyst particles and a precursor of a water-repellent silicone as essential components, and in addition, a solvent such as water, ethanol and propanol, hydrochloric acid, nitric acid, and the like. Catalysts that promote the hydrolysis of silica precursors such as sulfuric acid, acetic acid and maleic acid, basic compounds such as tributylamine and hexylamine, and acidic compounds such as aluminum triisopropoxide and tetraisopropyl titanate Such as a catalyst for curing a precursor of silica,
A surfactant such as a silane coupling agent for improving the dispersibility of the coating liquid may be added.

[0023] Here silicone - The precursor emissions in the average composition formula _{R p SiX q O (4-} pq) / 2 ( wherein, R consists of one or more organic groups monovalent functional X or a functional group comprising two or more selected from a monovalent organic group and a hydrogen group, X is an alkoxy group or a halogen atom, and p and q are 0 <p <2, 0 <
a film-forming element composed of a siloxane represented by the following formula: q <4) or a general formula R _p SiX _4-p (where R is one or more monovalent organic groups) Wherein X is an alkoxy group or a halogen atom, and p is 1 or 2. A film-forming element comprising a hydrolyzable silane derivative to be
Can be suitably used.

Here, as the coating film forming element comprising the hydrolyzable silane derivative, methyltrimethoxysilane,
Methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltributoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, Phenyltributoxysilane,
Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldibutoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, phenyl Methyldipropoxysilane, phenylmethyldibutoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltripropoxysilane, n-propyltributoxysilane, γ-glycoxydoxypropyltrimethoxysilane, γ -Acryloxypropyltrimethoxysilane and the like can be suitably used.

The film-forming element composed of the above-mentioned siloxane includes partial hydrolysis and dehydration-condensation polymerization of the above-mentioned hydrolyzable silane derivative, or partially hydrolyzate of the above-mentioned hydrolyzable silane derivative, tetramethoxysilane and tetramethoxysilane. It can be produced by dehydration polycondensation with a partial hydrolyzate such as ethoxysilane, tetrapropoxysilane, tetrabutoxysilane, diethoxydimethoxysilane and the like.

The coating method of the coating composition includes spray coating, dip coating, flow coating, spin coating, roll coating, brush coating, and sponge. A method such as coating can be suitably used. As a curing method, it can be carried out by polymerizing by heat treatment, standing at room temperature, ultraviolet irradiation, or the like.

A method of applying a solution containing a substance for preventing photocatalytic hydrophilization such as cobalt or a cobalt compound by photoexcitation and immobilizing the solution on the surface includes, for example, cobalt chloride, cobalt sulfate, cobalt iodide, bromide, and the like. cobalt,
Spray coating method, dip coating method, flow coating method, spin coating method, roll coating method, brushing water-soluble cobalt compounds such as cobalt acetate, cobalt chlorate and cobalt nitrate Coating, sponge coating, etc., photoreduction, heat treatment, alcohol
This is performed by fixing by a method such as reduction using a sacrificial oxidizing agent such as toluene.

[0028]

【Example】

Reference example. Anatase type titanium oxide sol (Nissan Chemical, TA
-15, nitric acid peptized type, pH = 1), silica sol (Nippon Synthetic Rubber, Glasca A solution, pH = 4), methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B solution) and ethanol are mixed. The coating liquid obtained by stirring for 2 to 3 hours was applied on a 5 × 10 cm square glazed tile base material (TOTOKIKI, AB02E11) by spray coating.
A heat treatment was performed at 200 ° C. for 15 minutes to obtain a # 1 sample having a surface layer formed of 11 parts by weight of anatase type titanium oxide particles, 6 parts by weight of silica, and 5 parts by weight of silicone. The contact angle of the # 1 sample with water was 92 °. Here, the contact angle with water was evaluated using a contact angle measuring device (Kyowa Interface Science, CA-X150) by the contact angle with water 30 seconds after a water droplet was dropped from the micro syringe. Next, the surface of the # 1 sample was irradiated for one day with an ultraviolet illuminance of 0.3 mW / cm ² using an ultraviolet light source (Sankyo Electric, Black Light Blue (BLB) fluorescent lamp) to obtain a # 2 sample. As a result, the contact angle with water of the # 2 sample was hydrophilized to 0 °. Next, # 1 sample and #
One sample was irradiated with a mercury lamp at an ultraviolet irradiance of 22.8 mW / cm ² for 2 hours, and the surface of each of the # 3 samples obtained was subjected to Raman spectroscopic analysis. As a result, a peak of methyl group observed on the surface of sample # 1 was not observed in sample # 3, but a peak of hydroxyl group was observed instead. From the above,
It can be seen that the organic group bonded to the silicon atom in the silicon molecule on the surface of the film by the photoexcitation of the anatase type titanium oxide which is a photocatalyst is replaced by a hydroxyl group and becomes hydrophilic.

Embodiment 1 Anatase type titanium oxide sol (Nissan Chemical, TA-15, peptized nitrate, pH = 1),
Silica sol (Nippon Synthetic Rubber, Glasca A solution, pH = 4)
And methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B solution), cobalt chloride hexahydrate, and ethanol, and agitated for 2-3 hours. -Applied to the tile substrate by
Heat treated at 15 ° C. for 15 minutes to obtain anatase type titanium oxide particles 1
A # 4 sample having a surface layer comprising 1 part by weight, 6 parts by weight of silica, 5 parts by weight of silicone, and 0.2 parts by weight of cobalt was obtained. The contact angle of the # 4 sample with water was 97 °. Here, the contact angle with water is measured using a contact angle measuring instrument (Kyowa Interface Science, CA-
X150), and evaluated by the contact angle with water 30 seconds after a water drop was dropped from the micro syringe. Next, the surface of the # 4 sample was irradiated with ultraviolet light of 0.3 mW / cm ² for one day using an ultraviolet light source (Sankyo Electric, Black Light Blue (BLB) fluorescent lamp) to obtain a # 5 sample. as a result,#
The contact angle of the five samples with water was still 95 °, maintaining water repellency. Therefore, it can be understood from the above that the hydrophilicity of the silicon on the surface of the coating film due to the photoexcitation of the anatase type titanium oxide as a photocatalyst is inhibited by cobalt. This is considered because the substitution of the hydroxyl group for the organic group bonded to the silicon atom in the silicon molecule on the surface of the coating is inhibited by cobalt.

Embodiment 2 FIG. Anatase type titanium oxide sol (Nissan Chemical, TA-15, peptized nitrate, pH = 1),
Silica sol (Nippon Synthetic Rubber, Glasca A solution, pH = 4)
And methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B solution) and ethanol, and the coating solution obtained by stirring for 2 to 3 hours is applied to a tile base material by a spray coating method. It was coated on the substrate and heat-treated at 150 ° C. for 15 minutes to form a surface layer comprising 11 parts by weight of anatase type titanium oxide particles, 6 parts by weight of silica and 5 parts by weight of silicone. Furthermore, after applying 0.3 g of an aqueous solution of cobalt chloride hexahydrate having a cobalt metal concentration of 50 μmol / g thereon, an ultraviolet light source (Sankyo Electric, Black Light Blue (BLB) fluorescent lamp) was applied.
UV light of 0.4 mW / cm ² with 10 UV light
The sample was irradiated for 10 minutes to fix cobalt on the substrate to obtain a # 6 sample. The contact angle of the # 6 sample with water was 96 °. Here, the contact angle with water is measured using a contact angle measuring device (Kyowa Interface Science, CA-X).
150), the contact angle with water was evaluated 30 seconds after a water drop was dropped from the micro syringe. Next, an ultraviolet light source (Sankyo Electric, Black Light Blue-
(BLB) fluorescent light) for 1 day at an ultraviolet illuminance of 0.3 mW / cm ² to obtain a # 7 sample. As a result, # 7
The contact angle of the sample with water was still 94 °, maintaining water repellency.
Therefore, it can be understood from the above that the hydrophilicity of the silicon on the surface of the coating film due to the photoexcitation of the anatase type titanium oxide as a photocatalyst is inhibited by cobalt. This is considered because the substitution of the hydroxyl group for the organic group bonded to the silicon atom in the silicon molecule on the surface of the coating is inhibited by cobalt.

Embodiment 3 FIG. The # 5 sample, the # 7 sample, and a polytetrafluoroethylene plate for comparison were placed under the roofed part of the building as shown in FIG. 4 and left for 4 months. As a result, stains were observed on the polytetrafluoroethylene plate, whereas no stains were observed on the # 5 and # 7 samples.

[0032]

According to the present invention, a photocatalyst particle, a water-repellent silicone, and a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst are provided on the inner surface of the tunnel at the substrate surface. Or a layer containing photocatalyst particles and a water-repellent silicone is formed on the surface of the substrate, and at least a part of the surface of the layer has the water-repellent property. By fixing a substance for preventing hydrophilicity of the silicon by photoexcitation of the photocatalyst of the silicone, the surface of the member can maintain water repellency for a long period of time, so that it is hardly permanently stained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a tunnel.

FIG. 2 is a diagram showing a surface structure of an inner wall of a tunnel according to the present invention.

FIG. 3 is a diagram showing another surface structure of the inner wall of the tunnel according to the present invention.

FIG. 4 is a diagram showing a method for setting a test sample according to the embodiment of the present invention.

[Description of Signs] 10: Tunnel 12: Wall 14: Interior board 16: Lighting

Claims (3)

[Claims] 1. A surface layer containing photocatalyst particles, water-repellent silicone, and a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst is formed on the surface of a substrate. The inner wall of a tunnel, which is characterized by: 2. A layer containing photocatalyst particles and a water-repellent silicone is formed on the surface of a base material, and at least a part of the surface of the layer is made hydrophilic by the photoexcitation of the photocatalyst of the water-repellent silicone. An inner wall of a tunnel, on which a substance for preventing erosion is fixed. 3. The tunnel inner wall according to claim 1, wherein the substance for preventing the photocatalyst from becoming hydrophilic by photoexcitation is cobalt or a cobalt compound.