JPH10159264A - Roofing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent snow and ice accretion on the surface of roofing material over a long period of time by forming a surface layer containing photocatalyst particles, water repellent silicone and antihydrophilic substances. SOLUTION: On the surface of base material, a surface layer is formed containing photocatalyst particles, water repellent silicone, and substances which are able to prevent hydrophilic phenomena due to photoexcitation of photocatalysts of water repellent silicone such as cobalt or cobalt compounds. Or, a layer containing photocatalyst particles and water repellent silicone is formed on the surface of the base material and moreover substances for preventing hydrophilic property due to photoexcitation of photocatalyst of water repellent silicone such as cobalt or cobalt compounds may be fixed in part of the layer surface. By doing this, the surface of the roofing material is able to maintain the water repellency over a long period of time and thus snow and ice accretion to the surface of the roofing material can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roofing material which is hardly iced and snowy.

[0002]

2. Description of the Related Art If ice or snow adheres to a roof, the roof may be deformed due to its weight if left unattended. For this reason, in snowfall areas, it is necessary to frequently remove snow, which has required a great deal of cost and labor.

[0003]

As a method for preventing the formation of icing snow, it is known that it is preferable to impart water repellency to the roof surface. When water repellency is imparted to the member surface, water droplets move around on the member surface. As a result, water droplets are less likely to adhere, and snow and ice are less likely to adhere because water droplets do not 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 roofing material that can maintain the water repellency of its surface for a long period of time, and to prevent icing and snow on the roofing material.

[0005]

According to the present invention, in order to solve the above-mentioned problems, photocatalyst particles, water-repellent silicone, and hydrophilization 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. Provides a roofing material to which a substance for preventing the water-repellent silicone from being hydrophilized by photoexcitation of the photocatalyst is fixed. By making the surface layer contain a substance such as cobalt or a cobalt compound for preventing the photocatalyst from becoming hydrophilic due to photoexcitation, the silicon can be produced by photoexcitation of the photocatalyst.
Can be prevented from becoming hydrophilic. 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 ice and snow can be prevented from attaching to the roofing material.

[0006]

FIG. 1 is a perspective view of a roofing material. In one embodiment of the present invention, as shown in FIG.
A surface layer containing a photocatalyst particle, silicon, and a substance for preventing hydrophilicity due to photoexcitation of a photocatalyst such as cobalt or a cobalt compound is formed on the surface of the base material. 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 substrate, and at least a part of the surface of the layer is made of cobalt or A substance for preventing hydrophilicity due to photoexcitation of a photocatalyst of a water-repellent silicone such as a cobalt compound is fixed.

A photocatalyst has an energy greater 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, it is exposed to sunlight during the day,
Sunlight is available.

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, 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.

A metal 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, 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 contains a precursor of silicon as an essential component of a substance for preventing photocatalytic particles, cobalt or a cobalt compound or the like from becoming hydrophilic by photoexcitation of a photocatalyst. 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.

[0016] 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 siloxane includes partial hydrolysis and dehydration-condensation polymerization of the hydrolyzable silane derivative, or partial hydrolyzate of the hydrolyzable silane derivative, tetramethoxysilane, 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 base material, and at least a part of the surface of the layer is formed by photoexcitation of the photocatalyst by the water-repellent silicone. A method for manufacturing a water-repellent member to which a substance for preventing hydrophilicity 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 has photocatalyst particles and a precursor of a water-repellent silicone as essential components, and in addition, a solvent such as water, ethanol, 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.

[0022] 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 siloxane includes partial hydrolysis and dehydration-condensation polymerization of the hydrolyzable silane derivative, or a partial hydrolyzate of the hydrolyzable silane derivative, tetramethoxysilane, 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 above 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.

The method of applying a solution containing a substance for preventing the photocatalyst such as cobalt or a cobalt compound from being hydrophilized by photoexcitation and fixing it 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.

[0027]

【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 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), cobalt chloride hexahydrate, and ethanol, and stirred for 2-3 hours. -Applied on a slat base material by the
Heat-treated at 0 ° C. for 15 minutes to obtain a # 4 sample having a surface layer formed of 11 parts by weight of anatase type titanium oxide particles, 6 parts by weight of silica, 5 parts by weight of silicone, and 0.2 parts by weight of cobalt. Was. 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. Then # 4
The sample surface 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 with water of the # 5 sample 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)
, Methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B Solution) and ethanol were mixed, and the mixture was stirred for 2 to 3 hours. Coated on a substrate, heat treated at 150 ° C for 15 minutes,
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 was formed. 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.

Example 3. # 5 sample inclined at 45 °,
Water was applied to the # 7 sample and the slate plate using a shower. As a result, while water droplets remained on the slat plate, the water droplets rolled down in the # 5 and # 7 samples.

[0031]

According to the present invention, in a roofing material, 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 surface of the base material. Or a photocatalyst particle and a water-repellent silicone on the surface of the substrate.
And a substance for preventing hydrophilicity of the water-repellent silicone by photoexcitation of the photocatalyst is fixed to at least a part of the surface of the layer. In addition, the surface of the member can maintain water repellency for a long period of time, thereby preventing icing and snow on the roofing material.

[Brief description of the drawings]

FIG. 1 is a perspective view of a roofing material.

FIG. 2 is a diagram showing a surface structure of a roofing material according to the present invention.

FIG. 3 is a diagram showing another surface structure of the roofing material according to the present invention.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B05D 7/24 303 B32B 33/00 B32B 33/00 E04D 1/28 A E04D 1/28 3/35 T 3/35 B B01J 23 / 74 311M

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. Roofing material characterized by being. 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. A roofing material, on which a substance for preventing erosion is fixed. 3. The roofing material according to claim 1, wherein the substance for preventing the photocatalyst from becoming hydrophilic by photoexcitation is cobalt or a cobalt compound.