JPH10182189A - Window glass for building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a window glass for buildings having the surface hardly fouling and hardly sticking waterdrops thereto. SOLUTION: This window glass for buildings has a substantially transparent surface layer, containing photocatalytic oxide particles, a silicone and a water repellent fluororesin and formed on a substrate surface or has a substantially transparent surface layer, containing the photocatalytic oxide particles, amorphous silica and the water repellent fluororesin and formed on the substrate surface. The contact angle of the surface thereof with water is preferably >=90 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an architectural window glass having antifouling properties and water droplet adhesion preventing properties.

[0002]

2. Description of the Related Art The outside of a window glass of a building is contaminated by combustion products such as smoke in exhaust gas and dust floating in the air. If the windowpane is dirty, the outside scenery is not easily seen and it is uncomfortable. For example, in the case of a windowpane of a high-rise building, cleaning is a high place operation, which is costly and involves risks. Also, in rainy weather, a large number of water droplets separated by rain fall on the outside of the window glass of the building, and the visibility is lost. Then again, the outside scenery is not clearly visible. Also, in cold weather or rainy weather, the inside of the window glass of the building tends to be cloudy, and the outside scenery can not be seen well.

[0003]

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an architectural window glass having a surface which is not easily stained and to which water droplets are not easily attached.

[0004]

According to the present invention, in order to solve the above-mentioned problems, a substantially transparent surface layer containing photocatalytic oxide particles, silicone and a water-repellent fluororesin is provided on a substrate surface. The present invention provides an architectural window glass characterized in that a glass is formed. By adopting a configuration in which a surface layer containing photocatalytic oxide particles, silicone and a water-repellent fluororesin is formed, when the photocatalyst is photoexcited, the silicon atom in the silicon molecule is photocatalytically acted upon. The bonded organic group is at least partially substituted with a hydroxyl group to exhibit hydrophilicity, and the silicone exhibits a hydrophilic portion exposed to the outside air and a water-repellent fluororesin exhibits water repellency exposed to the outside air. Both parts have a structure that is microscopically dispersed on the surface. Furthermore, due to the presence of the photocatalyst, the silicone in which the organic group bonded to the silicon atom in the silicone molecule has been at least partially substituted with a hydroxyl group in response to the photoexcitation of the photocatalyst maintains the permanent hydrophilicity. Therefore, the structure in which both the hydrophilic portion and the water-repellent portion are microscopically dispersed on the surface is maintained. In such a structure, since the hydrophilic surface and the water-repellent surface are adjacent to each other, the hydrophilic adherent that easily adapts to the hydrophilic surface does not adapt to the adjacent water-repellent portion. Conversely, hydrophobic deposits that are easily adapted to the water-repellent surface do not adapt to adjacent hydrophilic portions. for that reason,
Neither hydrophilic deposits nor hydrophobic deposits are adhered to the member surface, and the surface is maintained in a clean state. further,
If the contact angle of the surface with water is set to 90 ° or more during the production of the surface layer, the state is maintained in accordance with the photoexcitation of the photocatalyst, and the water droplets hardly adhere.

A substantially transparent surface layer containing photocatalytic oxide particles, amorphous silica, and a water-repellent fluororesin is formed on the surface of the base material. Provide architectural glazing. By forming a surface layer containing photocatalytic oxide particles, amorphous silica, and a water-repellent fluororesin, the amorphous silica in the surface layer is exposed to the outside and exhibits a hydrophilic portion, Both of the water-repellent portions of the water-repellent fluororesin exposed to the outside air are microscopically dispersed on the surface.
Further, the presence of the photocatalyst allows the amorphous silica to maintain its hydrophilicity permanently in response to the photoexcitation of the photocatalyst, so that both the hydrophilic portion and the water-repellent portion are microscopically visible on the surface. The distributed structure is maintained. In such a structure, since the hydrophilic surface and the water-repellent surface are adjacent to each other, the hydrophilic adherent that easily adapts to the hydrophilic surface does not adapt to the adjacent water-repellent portion. Conversely, hydrophobic deposits that are easily adapted to the water-repellent surface do not adapt to adjacent hydrophilic portions. Therefore, neither the hydrophilic deposit nor the hydrophobic deposit is fixed to the member surface, and the surface is maintained in a clean state. Further, the contact angle of the surface with water during the production of the surface layer is 9
When the angle is set to 0 ° or more, the state is maintained in accordance with the photoexcitation of the photocatalyst, and it is difficult for water droplets to adhere.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In one embodiment of the architectural window glass of the present invention, as shown in FIG. 1, the surface of the window glass substrate contains photocatalyst particles, silicone, and a water-repellent fluororesin. A surface layer is formed. In FIG. 1, when light capable of photo-exciting the photocatalyst is irradiated, at least a part of the silicon exposed to the outside air has at least a part of an organic group bonded to a silicon atom in the silicon molecule by photocatalysis. Hydroxyl groups are replaced by hydroxyl groups to become hydrophilic, and both the silicone-exposed hydrophilic portion exposed to the outside air and the water-repellent portion exposed to the water-repellent fluororesin are exposed to the surface. The structure becomes visually dispersed. Furthermore, the presence of the photocatalyst allows the amorphous silica to remain permanently hydrophilic in response to the photoexcitation of the photocatalyst,
The structure in which both the hydrophilic part and the water-repellent part are microscopically dispersed on the surface is maintained. Therefore,
With such a structure, neither the hydrophilic deposit nor the hydrophobic deposit is fixed to the member surface, and the surface is maintained in a clean state. Furthermore, if the contact angle of the surface with water is set to 90 ° or more during the production of the surface layer, the state is maintained in accordance with the photoexcitation of the photocatalyst, and water droplets hardly adhere.

In another embodiment of the present invention, as shown in FIG. 2, a surface layer containing photocatalyst particles, amorphous silica and a water-repellent fluororesin is formed on the surface of the substrate.
The photocatalyst particles, the amorphous silica, and the surface layer containing the water-repellent fluororesin are formed so that the amorphous silica in the surface layer is exposed to the outside air and exhibits a hydrophilic property. Both of the water-repellent portions where the resin is exposed to the outside air are microscopically dispersed on the surface.
Further, the presence of the photocatalyst allows the amorphous silica to maintain its hydrophilicity permanently in response to the photoexcitation of the photocatalyst, so that both the hydrophilic portion and the water-repellent portion are microscopically visible on the surface. The distributed structure is maintained. Therefore, by adopting such a structure, neither the hydrophilic deposit nor the hydrophobic deposit is fixed to the member surface.
The surface is kept clean. Furthermore, if the contact angle of the surface with water is set to 90 ° or more during the production of the surface layer, the state is maintained in accordance with the photoexcitation of the photocatalyst, and water droplets hardly adhere.

In order to make the contact angle with water on the surface 90 ° or more during the production of the surface layer, the amount of the fluororesin relative to the total amount of the photocatalytic oxide, the fluororesin and the silicone (or amorphous silica) in the surface layer is increased. 50% by weight or more
More preferably, the content is 60% by weight or more.

A photocatalyst has an energy greater than the energy gap between the conduction band and the valence band of the crystal.
A substance that can generate conduction electrons and holes by irradiating light (excitation light) with light (excitation light) of a short wavelength (excitation light). For example, oxides such as anatase type titanium oxide, rutile type titanium oxide, zinc oxide, tin oxide, ferric oxide, bismuth trioxide, tungsten trioxide and strontium titanate can be suitably used.

As the window glass substrate for construction, a transparent substrate such as glass, double-glazed glass, tempered glass, or transparent plastic, and a transparent body provided with a transparent hard coat thereon are preferably used. it can. Between the architectural window glass and the surface layer,
An intermediate layer made of silica, silicone, acrylic silicon, or the like may be provided for the purpose of improving the adhesion to the substrate.

As a light source used for photoexcitation of the photocatalyst, sunlight, indoor lighting, fluorescent lamps, incandescent lamps, metal halide lamps, mercury lamps, xenon lamps, germicidal lamps and the like can be suitably used. In order for the silicon or amorphous silica on the substrate surface to be hydrophilic by the photoexcitation of the photocatalyst, the illuminance of the excitation light may be 0.001 mW / cm ² or more.
It is preferably at least 0.01 mW / cm ² ,
cm2 or more is more preferable.

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 water-repellent fluororesin, polytetrafluoroethylene, polychlorotrifluoroethylene, polyhexafluoropropylene, tetrafluoroethylene-hexafluoropropylene copolymer 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 method for producing an antifouling member in which a surface layer containing photocatalytic oxide particles, silicone and a water-repellent fluororesin is formed on the surface of a substrate 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, as essential components, a silicone precursor in addition to the photocatalyst particles and the water-repellent fluororesin, and a solvent such as water, ethanol, propanol, and the like. Catalysts for promoting 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;
Catalysts for curing silicone precursors such as acidic compounds such as aluminum triisopropoxide and tetraisopropyl titanate;
A surfactant or the like for improving the dispersibility of the tinting liquid may be added.

[0019] 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 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 method for producing an antifouling member in which a surface layer containing photocatalyst particles, amorphous silica and a water-repellent fluororesin is formed on the surface of a substrate 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.

The coating composition contains silica particles or a silica precursor in addition to the photocatalyst particles and the water-repellent fluororesin as essential components. In addition, a solvent such as water, ethanol, propanol, etc. , Hydrochloric acid, nitric acid, sulfuric acid, acetic acid, maleic acid and other catalysts for promoting hydrolysis of silica precursors, basic compounds such as tributylamine and hexylamine, aluminum triisopropoxide and tetraisopropyl titanate For example, a catalyst for curing a silica precursor such as an acidic compound such as an acidic compound, or a surfactant for improving dispersibility of a coating liquid such as a silane coupling agent may be added.

Here, the precursor of the silicone is an average compositional formula SiX _q O _{(4-q) / 2} (where X is an alkoxy group or a halogen atom, and q is 0 <q <4). A film-forming element comprising a silicate represented by the following formula: or a general formula SiX ₄ (wherein R is a functional group comprising one or more monovalent organic groups, or And X is an alkoxy group or a halogen atom, and X is a functional group consisting of two or more kinds selected from a monovalent organic group and a hydrogen group. Forming elements and the like can be suitably used.

Here, the coating film forming element comprising the above-mentioned tetrafunctional hydrolyzable silane derivative includes tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane,
Tetrabutoxysilane, diethoxydimethoxysilane and the like can be suitably used.

Further, the coating film forming element comprising the above silicate can be prepared by partial hydrolysis, dehydration condensation polymerization, etc. of the above tetrafunctional hydrolyzable silane derivative.

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.

[0029]

【Example】

Reference example. Anatase type titanium oxide sol (Nissan Chemical, TA
-15, nitric acid peptizer, pH = 1), silica sol (Nippon Synthetic Rubber, Glasca A solution, pH = 4), methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B solution) and ethanol were mixed. The coating liquid obtained by stirring for 2 to 3 minutes was applied onto a 10 cm square soda lime glass substrate by a spray coating method, and heat-treated at 200 ° C. for 15 minutes to form an anatase. A # 1 sample having a surface layer formed of 11 parts by weight of zeolite titanium oxide particles, 6 parts by weight of silica, and 5 parts by weight of silicone was obtained. The contact angle of the # 1 sample with water was 85 °. 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, 0.3 mW was applied to the # 1 sample surface using an ultraviolet light source (Sankyo Electric, Black Light Blue (BLB) fluorescent lamp).
Irradiation was carried out for one day at an ultraviolet illuminance of / cm ² to obtain a # 2 sample.
As a result, the contact angle with water of the # 2 sample was hydrophilized to 0 °. Next, a mercury lamp was used for the sample # 1 and the sample # 2 for 22.8.
The surface of each of the # 3 samples obtained by irradiating with an ultraviolet illuminance of mW / cm ² for 2 hours was subjected to Raman spectroscopic analysis. as a result,#
(1) No peak of methyl group observed on the surface of the sample was observed in the # 3 sample, and a peak of brood of hydroxyl group was observed instead. From the above, the organic group bonded to the silicon atom in the silicon molecule on the surface of the film in response to the photoexcitation of the anatase type titanium oxide as the photocatalyst is replaced with a hydroxyl group by photocatalysis, and It can be seen that

Embodiment 1 Anatase type titanium oxide sol (Nissan Chemical, TA-15) and silica sol (Nippon Synthetic Rubber,
(Glaska A solution), methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B solution), polytetrafluoroethylene (PTFE) particles (Daikin Industries, Lubron L-5) and ethanol are mixed and stirred for 2 to 3 hours. The thus obtained coating liquid was applied on a 10 cm square soda lime glass plate by a spray coating method, and heat-treated at 200 ° C. for 15 minutes to obtain 33 weight of anatase type titanium oxide particles. , A surface layer consisting of 66 parts by weight of polytetrafluoroethylene particles, 6 parts by weight of silica and 5 parts by weight of silicone
A sample was prepared. The contact angle of the # 4 sample with water was 110 °. 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 # 5 sample with water was 97.
There was not much change with 2 ゜. From the above reference example, the part where the silicon was exposed to the outside air should be replaced by the hydroxyl group by photocatalysis and the organic group bonded to the silicon atom in the silicon molecule to be hydrophilized. It is considered that the contact angle with water was slightly reduced due to hydrophilization. In other words, the surface of the # 5 sample is divided into a hydroxyl-substituted photocatalytically substituted hydroxyl group and a hydrophilic portion exposed to the outside air, and a water-repellent portion exposed to the water-repellent fluororesin. It is presumed that both have a structure microscopically dispersed on the surface. The contact angle with water is 9
When the angle was 7.2 ° and 90 ° or more, when the glass was tilted, the water droplets rolled and fell.

[0031]

According to the present invention, in an architectural window glass,
Since a substantially transparent surface layer containing photocatalytic oxide particles, a water-repellent fluororesin, and silicone or amorphous silica is formed on the surface of the window glass substrate, hydrophilic deposits are formed. Both the water and the hydrophobic deposits are less likely to adhere to the surface of the window glass, and the surface is maintained in a clean state.
Further, when the contact angle of the surface with water is 90 ° or more, water droplets are less likely to adhere to the window glass surface.

[Brief description of the drawings]

FIG. 1 is a view showing a surface structure of a building window glass according to the present invention.

FIG. 2 is a diagram showing another surface structure of the architectural window glass according to the present invention.

Claims (4)

[Claims] 1. An antifouling property wherein a substantially transparent surface layer containing photocatalytic oxide particles, silicone and a water-repellent fluororesin is formed on the surface of a window glass substrate. Architectural glazing with. 2. A substantially transparent surface layer containing photocatalytic oxide particles, silicone and a water-repellent fluororesin is formed on the surface of the window glass substrate, and the surface of the layer is made of water. A window glass for architecture having both antifouling property and water droplet adhesion preventing property, wherein the contact angle is 90 ° or more. 3. An antifouling property characterized in that a substantially transparent surface layer containing photocatalytic oxide particles, amorphous silica and a water-repellent fluororesin is formed on the surface of the base material. Architectural glazing. 4. A substantially transparent surface layer containing photocatalytic oxide particles, amorphous silica, and a water-repellent fluororesin is formed on the surface of the substrate, and the surface of the layer is in contact with water. An architectural window glass having an antifouling property and an anti-waterdrop property, wherein the angle is 90 ° or more.