Vehicle pane for securing rainy weather view, and automobile mounted therewith

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to vehicle glass that can be used for automobile windshields, side glasses, and the like.

【0002】

[Conventional technology]

Vehicle glass such as automobile windshields and side glasses are exposed to rain or spray in the rain, and a large number of scattered water droplets adhere to the surface, causing the surface to become dull, blurred, mottled, or cloudy or visible. Loss of sex is often experienced. If the condensed water droplets are sufficiently fine and their diameter is about half the wavelength of visible light, the water droplets scatter the light, the vehicle mirror becomes apparently opaque, and visibility is lost. As the condensation of the wet matter progresses further and the fine condensed water droplets fuse with each other to grow into larger discrete water droplets, the surface becomes blunt due to the refraction of light at the interface between the water droplet and the surface and the interface between the water droplet and the air. Blurred, mottled, or cloudy, loss of visibility. Vehicle windshields, side glasses, and other vehicle glass are exposed to rainfall and spray, and a large number of scattered water droplets adhere to the surface, causing the surface to become dull, blurry, mottled, or cloudy or visible. If it is lost, it will hinder the safe driving of the car.

【0003】

As is well known, windshield wipers, defrosting devices, and heaters are generally incorporated in the windshield of automobiles and other vehicles to ensure visibility in rainy weather.

【0004】

[Problems to be Solved by the Invention]

However, if a heater is simply incorporated into the vehicle glass, it takes time to dry it when a large amount of raindrops adhere to it. In addition, in the process of drying raindrops, the diameter of the raindrops becomes smaller and the raindrops dry, so that the raindrops may become cloudy just before they dry (when the wavelength of visible light becomes about 1/2). Therefore, an object of the present invention is to provide a vehicle glass having excellent visibility in rainy weather, which dries quickly even when a large amount of raindrops are attached and does not cause fogging immediately before drying.

【0005】

[Means for solving problems]

The present invention is based on the discovery that in a member having a surface layer containing a photocatalyst, when the photocatalyst is photoexcited, the surface of the member becomes highly hydrophilic. This phenomenon is considered to proceed by the mechanism shown below. That is, when the photocatalyst is irradiated with light having an energy equal to or greater than the energy gap between the upper end of the valence band and the lower end of the conduction band of the photocatalyst, the electrons in the valence band of the photocatalyst are excited to generate conduction electrons and holes. , Either or both of them will probably impart polarity to the surface and collect polar components such as water and hydroxyl bands. Then, by the cooperative action of either or both of conduction electrons and holes and the polar component, the chemical bond between the surface and the pollutant chemically adsorbed on the surface is broken, and the chemically adsorbed water on the surface. Is adsorbed, and a physically adsorbed aqueous layer is formed on it. Further, once the surface of the member is highly hydrophilic, the hydrophilicity of the surface is maintained for a certain period of time even if the member is held in a dark place.

【0006】

The present invention provides a glass for a vehicle having a viewability in rainy weather, which comprises a surface layer containing substantially transparent photocatalytic particles on the surface of a glass substrate for a vehicle with a heater. By providing a surface layer containing a photocatalyst, the surface of the surface layer becomes hydrophilic in response to photoexcitation of the photocatalyst, so that condensed water and / or water droplets of adhering moisture are one on the surface of the layer. It spreads like this, and drying by the heater is promoted. Further, since the raindrops are not retained during drying, it is considered that cloudiness does not occur immediately before drying.

【0007】

In a preferred embodiment of the present invention, the surface layer is further contained with silica. By containing silica, the surface tends to exhibit a high degree of hydrophilicity close to a water wetting angle of 0 °, and the hydrophilicity retention when held in a dark place is improved. The reason seems to be related to the ability of silica to store water in its structure.

【0008】

In a preferred embodiment of the present invention, the surface layer is further contained with a solid acid. By containing the solid acid, the surface tends to exhibit a high degree of hydrophilicity close to a water wetting angle of 0 °, and the hydrophilicity retention when held in a dark place is improved. The reason is that when the surface layer contains a solid acid, the polarity of the surface is large regardless of the presence or absence of light, so that it is easier to selectively adsorb water molecules, which are polar molecules, than hydrophobic molecules. .. Therefore, a stable physically adsorbed aqueous layer is easily formed, and even if it is kept in a dark place, the hydrophilicity of the surface can be maintained at a high level for a considerably long period of time.

【0009】

In a preferred embodiment of the present invention, the surface layer is further contained with silicone. Due to the inclusion of silicone, at least a part of the organic groups bonded to the silicon atoms in the silicone is replaced with hydroxyl groups by the photoexcitation of the photocatalyst, and a physically adsorbed aqueous layer is formed on the hydroxyl groups, so that the surface is surfaced. It exhibits a high degree of hydrophilicity close to a water wetting angle of 0 °, and improves hydrophilicity retention when held in a dark place.

【0010】

BEST MODE FOR CARRYING OUT THE INVENTION

Next, a specific configuration example of the present invention will be described. As shown in FIG. 1 or 2, a layer containing a photocatalyst is formed on the surface of the base material on the surface of the glass for a vehicle for ensuring visibility in rainy weather in the present invention. The heater is mounted on the back surface of the glass substrate or is formed in the form of a transparent thin film between the glass substrate and the layer containing the photocatalyst. By adopting such a surface structure, the glass surface for a vehicle is highly hydrophilized in response to photoexcitation of a photocatalyst. As a result, even if the moisture in the atmosphere condenses and adheres, it does not grow in the form of water droplets, but becomes a uniform water film, and drying by the heater is promoted. Further, since the raindrops are not retained during drying, it is considered that cloudiness does not occur immediately before drying.

【0011】

In FIG. 1, when the surface layer is composed only of a photocatalyst, the photocatalyst is preferably an oxide. By doing so, the oxide exhibits hydrophilicity when the pollutants in the environment are not adsorbed. Therefore, the pollutants are eliminated by the photoexcitation action to form an adsorbed aqueous layer, so that the oxides tend to exhibit hydrophilicity. , A uniform water film can be formed. In FIG. 2, M represents a metallic element. Therefore, in the case of FIG. 2, the outermost surface is made of a general inorganic oxide. In this case as well, since the oxide exhibits hydrophilicity when the pollutants in the environment are not adsorbed, the pollutants are eliminated by the photoexciting action of the photocatalytic titanium oxide mixed in the surface layer in addition to the above-mentioned inorganic oxides. By forming an adsorbed aqueous layer, a uniform aqueous film can be formed.

【0012】

As the glass base material for vehicles in the present invention, transparent base materials such as glass, double glazing, tempered glass, and transparent plastic, and transparent materials having a transparent hard coat on them can be preferably used.

【0013】

A photocatalyst is an excitation (photoexcitation) of electrons in the valence band when irradiated with light (excitation light) having an energy larger than the energy gap between the conduction band and the valence band of the crystal (that is, a short wavelength). ) Is generated and can generate conduction electrons and holes. For example, anatase-type titanium oxide, rutile-type titanium oxide, tin oxide, zinc oxide, dibismus trioxide, tungsten trioxide, ferric oxide, etc. Strontium titanate and the like can be preferably used. Here, as the light source used for photoexcitation of the photocatalyst, a light source in a driving environment such as sunlight, a street light, a tunnel lighting, a nightlight, etc. may be used, and the excitation light can be irradiated as ancillary equipment or portable equipment. A light source may be used. As the light source used in that case, for example, a fluorescent lamp, an incandescent lamp, a metal halide lamp, a mercury lamp, a xenon lamp, a germicidal lamp and the like can be preferably used. In order for the surface of the substrate to be highly hydrophilic by photoexcitation of the photocatalyst, the illuminance of the excitation light should be 0.001 mW / cm2 or more, but 0.01 mW / cm.²Above is preferable, 0.1mW / cm²The above is more preferable.

【0014】

The film thickness of the surface layer containing the photocatalyst is preferably 0.4 μm or less. By doing so, it is possible to prevent white turbidity due to diffused reflection of light, and the surface layer becomes substantially transparent. Further, it is more preferable that the film thickness of the surface layer containing the photocatalyst is 0.2 μm or less. By doing so, it is possible to prevent color development of the surface layer due to light interference. Further, the thinner the surface layer, the higher the transparency. Further, if the film thickness is reduced, the wear resistance of the surface layer is improved. A wear-resistant or corrosion-resistant protective layer or another functional film that can be hydrophilized may be further provided on the surface of the surface layer.

【0015】

It is preferable that the surface layer does not have a high refractive index as compared with the base material. Preferably, the refractive index of the surface layer is 2 or less. Then, the reflection of light at the interface between the base material and the surface layer and the interface between the surface layer and air can be suppressed. To reduce the refractive index of the surface layer to 2 or less, use a substance having a refractive index of 2 or less for the photocatalyst, or when the photocatalyst has a refractive index of 2 or more, use another substance having a refractive index of 2 or less for the surface layer. Add to. As a photocatalyst having a refractive index of 2 or less, tin oxide (refractive index 1.9) or the like can be used. Photocatalysts having a refractive index of 2 or more include anatase-type titanium oxide (refractive index 2.5) and rutile-type titanium oxide (refractive index 2.7). Calcium (refractive index 1.6), calcium hydroxide (refractive index 1.6), magnesium carbonate (refractive index 1.5), strontium carbonate (refractive index 1.5), dolomite (refractive index 1.7), calcium fluoride (refractive index 1.4), fluoride Magnesium (refractive index 1.4), silica (refractive index 1.5), alumina (refractive index 1.6), silica sand (refractive index 1.6), montmorillonite (refractive index 1.5), kaolin (refractive index 1.6), sericite (refractive index 1.6) , Zeolite (refractive index 1.5), tin oxide (refractive index 1.9), etc. may be added to the surface layer.

【0016】

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 mold adhering to the surface even in a dark place.

【0017】

Platinum group metals such as Pt, Pd, Ru, Rh, Ir and Os can be added to the surface layer. The surface layer to which the metal is added can enhance the redox activity of the photocatalyst, and the deodorizing and purifying action and the like are improved. In addition, when a solid acid is added in addition to the photocatalyst, the acidity of the solid acid is improved by the addition of the platinum group metal, so that the hydrophilicity retention property is also improved, the water film formation of the adhered water is further promoted, and to some extent. The hydrophilicity retention property is also improved when the photocatalyst is not irradiated with excitation light for a long period of time. Mo can be added to the surface layer. When a solid acid is added in addition to the photocatalyst, the addition of Mo improves the acidity of the solid acid, so that the hydrophilicity retention is also improved, the water film formation of the adhered water is further promoted, and the photocatalyst is excited for a certain period of time. The hydrophilicity retention when not irradiated with light is also improved.

【0018】

When the base material is glass containing alkaline network-modifying ions such as sodium (soda lime glass, parallel plate glass, etc.), an intermediate layer such as silica may be formed between the base material and the surface layer. By doing so, the alkali network-modifying ions are prevented from diffusing from the base material to the surface layer during firing, and the photocatalytic function is better exhibited.

【0019】

Hydrophilicity refers to the property of being easily adapted when water is dropped on the surface, and generally refers to a state in which the water wetting angle is less than 90 °. The high degree of hydrophilicity in the present invention means a property that is very familiar when water is dropped on the surface, and more specifically, a state in which the water wetting angle is about 10 ° or less. In particular, as disclosed in PCT / JP96 / 00734, the antifogging property preferably has a water wetting angle of 10 ° or less, and more preferably 5 ° or less.

【0020】

The solid acid in the present invention includes sulfuric acid-supported Al.₂O₃, Sulfuric acid supported TiO₂, Sulfuric acid-supported ZrO₂, Sulfuric acid-supported SnO₂, Sulfuric acid supported Fe₂O₃, Sulfuric acid supported SiO₂, Sulfuric acid-supported HfO₂, TiO₂/ WO₃, WO₃/ SnO₂, WO₃/ ZrO₂, WO₃/ Fe₂O₃, SiO₂ Al₂O₃, TiO₂/ SiO₂, TiO₂/ Al₂O₃, TiO₂/ ZrO₂Etc. can be preferably used.

【0021】

Next, a method of forming the surface layer will be described. First, a manufacturing method when the surface layer is composed of only a photocatalyst will be described by taking the case where the photocatalyst is anatase-type titanium oxide as an example. The method in this case is roughly divided into three methods. One method is a sol coating firing method, the other method is an organic titanate method, and the other method is an electron beam deposition method. (1) Sol coating and firing method Anatase-type titanium oxide sol is applied to the surface of a substrate by a method such as a spray coating method, a dip coating method, a flow coating method, a spin coating method, or a roll coating method, and fired. (2) Organic titanate method Add a hydrolysis inhibitor (hydrolysis, ethylamine, etc.) to organic titanates such as titanium alkoxide (tetraethoxytitanium, tetramethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, etc.), titanium acetate, titanium chelate, etc., and alcohol (ethanol, propanol, etc.). , Butanol, etc.), and then the mixture is spray-coated, dip-coated, flow-coated, spin-coated, with partial or complete hydrolysis. Apply by method, roll coating method, etc. and dry. Drying completes the hydrolysis of organic titanate to produce titanium hydroxide, and dehydration polycondensation of titanium hydroxide forms a layer of amorphous titanium oxide on the surface of the substrate. Then, it is calcined at a temperature equal to or higher than the crystallization temperature of anatase to perform a phase transition of amorphous titanium oxide to anatase type titanium oxide. (3) Electron beam deposition method By irradiating the titanium oxide target with an electron beam, an amorphous titanium oxide layer is formed on the surface of the base material. Then, it is calcined at a temperature equal to or higher than the crystallization temperature of anatase to perform a phase transition of amorphous titanium oxide to anatase type titanium oxide.

【0022】

Next, the case where the surface layer is composed of a photocatalyst and silica will be described by taking the case where the photocatalyst is anatase-type titanium oxide as an example. In this case, for example, there are the following three methods. One method is the sol coating firing method, the other method is the organic titanate method, and the other method is the tetrafunctional silane method. (1) Sol coating and firing method A mixed solution of anatase-type titanium oxide sol and silica sol is applied to the surface of the base material by a method such as a spray coating method, a dip coating method, a flow coating method, a spin coating method, or a roll coating method, and fired. (2) Organic titanate method Hydrolysis inhibitor (hydrolysis, ethylamine, etc.) and silica sol are added to organic titanates such as titanium alkoxide (tetraethoxytitanium, tetramethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, etc.), titanium acetate, titanium chelate, etc., and alcohol (ethanol). , Propanol, butanol, etc.), and then the mixture is spray-coated, dip-coated, flow-coated, with partial or complete hydrolysis. Apply by a method such as spin coating method or roll coating method, and dry. Drying completes the hydrolysis of organic titanate to produce titanium hydroxide, and dehydration polycondensation of titanium hydroxide forms a layer of amorphous titanium oxide on the surface of the substrate. Then, it is calcined at a temperature equal to or higher than the crystallization temperature of anatase to perform a phase transition of amorphous titanium oxide to anatase type titanium oxide. (3) 4-functional silane method A mixture of tetraalkoxysilane (tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetramethoxysilane, etc.) and anatase-type titanium oxide sol is spray-coated, dip-coated, flow-coated, spin-coated on the surface of the substrate. , The roll coating method or the like is applied, and if necessary, the silanol is hydrolyzed to form silanol, and then the silanol is subjected to dehydration-condensation polymerization by a method such as heating.

【0023】

Next, in the case where the surface layer consists of a photocatalyst and a solid acid, the photocatalyst is anatase-type titanium oxide and the solid acid is TiO.₂/ WO₃The case of is described as an example. One method in this case is to mix an ammonia solution of tungstic acid and anatase-type titanium oxide sol, and if necessary, spray-coat the surface of the substrate with a mixture diluted with a diluent (water, ethanol, etc.). It is applied and fired by a method such as a dip coating method, a flow coating method, a spin coating method, or a roll coating method. Another method is to form an atypical titanium oxide film by electron beam deposition, hydrolysis of organic titanates such as titanium alkoxide, titanium acetate, and titanium chelate, and dehydration polycondensation, and then apply tungsten acid to the atypical titanium oxide. Crystallizes and TiO₂/ WO₃Heat treat at the temperature at which the composite oxide is formed.

【0024】

Next, the case where the surface layer is composed of a photocatalyst and silicone will be described by taking the case where the photocatalyst is anatase-type titanium oxide as an example. In this case, the method is to mix a paint consisting of uncured or partially cured silicone or a silicone precursor with anatase-type titanium oxide sol, hydrolyze the silicone precursor if necessary, and then mix. Is applied to the surface of the base material by a method such as a spray coating method, a dip coating method, a flow coating method, a spin coating method, or a roll coating method, and the hydrolyzate of the silicone precursor is subjected to dehydration polycondensation by a method such as heating. To form a surface layer composed of anatase-type titanium oxide particles and silicone. In the formed surface layer, at least a part of the organic group bonded to the silicon atom in the silicone molecule is replaced with a hydroxyl group by photoexciting the anatase-type titanium oxide by irradiation with light including ultraviolet rays, and further on the surface layer. A physically adsorbed aqueous layer is formed to exhibit a high degree of hydrophilicity. Here, the precursors of silicone include methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltributoxysilane, ethyltripropoxysilane, and phenyl. Trimethoxysilane, phenyltriethoxysilane, phenyltributoxysilane, phenyltripropoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldibutoxysilane, dimethyldipropoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldibutoxy Silane, diethyldipropoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, phenylmethyldibutoxysilane, phenylmethyldipropoxysilane, γ-glycidoxypropyltrimethoxysilane, and their hydrolyzates, mixtures thereof. Can be preferably used.

【0025】

In addition, a film coated with the above coating may be attached to the surface of the base material with a transparent adhesive such as soapy water. Here, as the film base material, a plastic film such as polyethylene terephthalate, polyester, or polyethylene can be preferably used.

【0026】

[Example]

Example 1. (+ Amorphous silica) A coating solution was prepared by mixing 0.69 g of tetraethoxysilane (Wako Pure Chemical Industries, Ltd.), 1.07 g of anatase-type titanium oxide sol (Nissan Chemical, TA-15, average particle size 10 nm), 29.88 g of ethanol, and 0.36 g of pure water. This coating liquid was applied onto a 10 cm square glass substrate by the flow coating method. By holding this glass plate at a temperature of about 150 ° C for about 20 minutes, tetraethoxysilane is subjected to hydrolysis and dehydration polycondensation, and a coating in which anatase-type titanium oxide particles are bound with amorphous silica is applied to the glass. Formed on the plate surface. The weight ratio of titanium oxide to silica in this coating was 1. After leaving this glass plate in the dark for several days, 0.5 mW / cm on the surface of the sample using an ultraviolet light source (Sankyo Electric, Black Light Blue (BLB) fluorescent lamp).²A # 1 sample was obtained by irradiating with ultraviolet rays for about 1 hour with the ultraviolet illuminance of. For comparison, a # 2 sample in which a 10 cm square glass end plate was left in the dark for several days was also prepared. First, water droplets were dropped on the # 1 sample and the # 2 sample, and the state after the drops was observed and the contact angle with water was measured. Here, the contact angle with water was evaluated using a contact angle measuring device (Kyowa Interface Science, CA-X150) based on the contact angle with water 30 seconds after dropping. As a result, when water droplets were dropped on the sample surface from the microsyringe of the # 1 sample, it was observed that the water droplets uniformly spread on the sample surface in the form of a water film. The contact angle with water after 30 seconds was highly hydrophilic to about 0 °. On the other hand, in the # 2 sample, when water droplets were dropped from the microsyringe onto the sample surface, the water droplets became familiar with the surface, but did not reach a uniform water film shape. The contact angle with water after 30 seconds is 30. It was. Next, the surfaces of the # 1 sample and the # 2 sample were heated to set the surface temperature to 45 ° C. About 1 ml of water droplets were dropped on the surfaces of # 1 and # 2 samples, and the drying time was measured. As a result, it took 7 minutes for the # 2 sample to dry, whereas it took about 2 minutes and 40 seconds for the # 1 sample. In addition, the # 1 sample and the # 2 sample were blown to examine the presence or absence of fogging. As a result, the # 2 sample was cloudy, whereas the # 1 sample was not cloudy. Further, the # 1 sample was left in a dark place for 2 days thereafter to obtain a # 3 sample. Then, for the # 3 sample, the contact angle with water was similarly measured with a contact angle measuring device. As a result, when water droplets were dropped on the sample surface from the microsyringe on the # 3 sample, it was observed that the water droplets uniformly spread on the sample surface in the form of a water film, similar to the # 1 sample. The contact angle with water was maintained at about 3 °. Next, the presence or absence of cloudiness after blowing on the # 3 sample was observed. As a result, no cloudiness was observed.

【0027】

Example 2. (+ TiO₂/ WO₃) An amorphous titanium oxide film is adhered to the surface of a 10 cm square soda lime glass plate by an electron beam deposition method, and then fired at a temperature of 500 ° C to crystallize the amorphous titanium oxide and anatase type titanium oxide. Was generated. The film thickness of the anatase-type titanium oxide film was 100 nm. Furthermore, tungstic acid dissolved in 25% aqueous ammonia on it is converted to the weight of tungstic acid by 0.6 μg / cm.²Was applied and then fired at a temperature of 500 ° C. After leaving this glass plate in a dark place for several days, the surface of the sample was irradiated with ultraviolet rays at an illuminance of 0.5 mW / cm2 for about 1 hour using a BLB fluorescent lamp to obtain a # 4 sample. For comparison, the # 2 sample used in Example 1 in which a 10 cm square glass plate was left in a dark place for several days was also prepared. First, water droplets were dropped on the # 4 sample and the # 2 sample, and the state after the drops was observed and the contact angle with water was measured. As a result, when water droplets were dropped on the sample surface from the microsyringe of the # 4 sample, it was observed that the water droplets uniformly spread on the sample surface in the form of a water film. The contact angle with water after 30 seconds was highly hydrophilic to about 0 °. On the other hand, in the # 2 sample, when water droplets were dropped from the microsyringe onto the sample surface, the water droplets became familiar with the surface, but did not reach a uniform water film shape. The contact angle with water after 30 seconds is 30. It was. Next, the surfaces of the # 1 sample and the # 2 sample were heated to set the surface temperature to 45 ° C. About 1 ml of water droplets were dropped on the surfaces of # 1 and # 2 samples, and the drying time was measured. As a result, it took 7 minutes for the # 2 sample to dry, whereas it took about 2 minutes and 40 seconds for the # 1 sample. Next, the # 4 sample and the # 2 sample were blown to examine the presence or absence of fogging. As a result, the # 2 sample was cloudy, whereas the # 4 sample was not cloudy. Further, the # 4 sample was left in a dark place for 2 days thereafter to obtain a # 5 sample. Then, for the # 5 sample, the contact angle with water was similarly measured with a contact angle measuring device. As a result, when water droplets were dropped on the sample surface from the microsyringe on the # 5 sample, it was observed that the water droplets uniformly spread on the sample surface in the form of a water film, similar to the # 4 sample. The contact angle with water was maintained at about 1 °. Next, the presence or absence of cloudiness after blowing on the # 5 sample was observed. As a result, no cloudiness was observed.

【0028】

Example 3. (+ TiO₂/ Amorphous silica, film sticking) First, a 10 cm square polyethylene terephthalate (PET) film is treated with corona discharge, then a primer (Shin-Etsu Chemical, PC-7A) is applied by the flow coating method, and a primer layer is formed by heat treatment at 120 ° C for 5 minutes. did. Next, after the primer layer was subjected to corona discharge treatment, a silicone hard coating liquid was applied by a flow coating method and heat-treated at 120 ° C. for 10 minutes to form a hard coating layer. Next, after corona discharge treatment of the hard coating layer, a photocatalytic coating liquid (a mixed liquid in which 13 parts by weight of titanium oxide and 7 parts by weight of tetraethoxysilane are dispersed in a mixed solvent of water and alcohol) is applied by a flow coating method. , A photocatalytic film was obtained by drying at room temperature for 10 minutes. Soap water was applied to the back side of this film and attached to the surface of a 10 cm square glass substrate. After leaving this glass end plate in the dark for several days, 0.5 mW / cm on the surface of the sample using a BLB fluorescent lamp.²A # 6 sample was obtained by irradiating with ultraviolet rays for about 1 hour under the ultraviolet illuminance of. For comparison, a # 7 sample in which a 10 cm square polyethylene terephthalate (PET) film was applied to the back side with soapy water and attached to the surface of a 10 cm square glass substrate was also prepared. First, water droplets were dropped on the # 6 sample and the # 7 sample, and the state after the drops was observed and the contact angle with water was measured. Here, the contact angle with water was evaluated by using a contact angle measuring device (Kyowa Interface Science, CA-X150) and the contact angle with water 30 seconds after dropping. As a result, it was observed that when water droplets were dropped on the sample surface of the # 6 sample from the microsyringe, the water droplets uniformly spread on the sample surface in the form of a water film. The contact angle with water after 30 seconds was highly hydrophilic to about 0 °. On the other hand, in the # 7 sample, when water droplets were dropped from the microsyringe onto the sample surface, the water droplets remained in the form of water droplets. The contact angle with water after 30 seconds is 80. It was. Next, the surfaces of the # 1 sample and the # 2 sample were heated to set the surface temperature to 45 ° C. About 1 ml of water droplets were dropped on the surfaces of # 1 and # 2 samples, and the drying time was measured. As a result, it took 10 minutes for the # 2 sample to dry, whereas it took about 2 minutes and 40 seconds for the # 1 sample. Next, the # 6 sample and the # 7 sample were blown to examine the presence or absence of fogging. As a result, the # 7 sample was cloudy, whereas the # 6 sample was not cloudy. Further, the # 6 sample was left in a dark place for 2 days thereafter to obtain a # 7 sample. Then, for the # 7 sample, the contact angle with water was similarly measured with a contact angle measuring device. As a result, when water droplets were dropped on the sample surface from the microsyringe on the # 7 sample, it was observed that the water droplets uniformly spread on the sample surface like a water film as in the # 6 sample. The contact angle with water was maintained at about 3 °. Next, the presence or absence of cloudiness after blowing on the # 7 sample was observed. As a result, no cloudiness was observed.

【0029】

[Effect of the invention]

In the present invention, by providing a surface layer containing substantially transparent photocatalyst particles on the glass surface for a vehicle with a heater, the surface of the surface layer becomes hydrophilic in response to photoexcitation of the photocatalyst, and rainfall is received in rainy weather. Condensed water and / or water droplets of moisture adhering due to spraying or spraying spread uniformly on the surface of the layer, and drying by a heater is promoted, so that visibility in rainy weather is ensured.

[Simple explanation of drawings]

[Figure 1]

The figure which shows the surface structure of the vehicle glass which concerns on this invention.

[Figure 2]

The figure which shows the other surface structure of the vehicle glass which concerns on this invention.