JP2001019494A - Anti-fog glass articles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antifogging glass article which has excellent performance with respect to hydrophoilicity retention properties after stopping UV irradiation of the article and the hydrophilicity of which can be improved by very weak UV irradiation and also which has good antifogging performance retainable over a long period. SOLUTION: This glass article is formed by successively laminating an alkali barrier film, a photocatalyst film and an overcoat film on the surface of a glass substrate in this order and has recessed and projecting parts formed in the surface, wherein the photocatalyst film contains titanium oxide of >=30 wt.% and an iron compound (desirably iron oxide) of 0.001-10 wt.% expressed in terms of Fe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article in which the surface of a glass substrate is made hydrophilic and antifogging property is exhibited.

2. Description of the Related Art There has been a strong need for anti-fog glass plates for a long time mainly in the field of automobiles and construction. Particularly in automobiles, the provision of anti-fog properties on window glass is becoming an important issue from the viewpoint of safe driving.

Conventionally, various anti-fog coatings on glass articles have been studied. For example, a coating of an organic and / or inorganic thin film containing a surfactant (Japanese Patent Laid-Open No.
7-117202, method 1), coating of a hydrophilic polymer (patent 1344292, method 2), coating of an organic-inorganic composite film containing a hydrophilic organic functional group (JP-A-6-220428, method 3), and the like.

[0003] Although the above method 1 is excellent in initial performance, it has a drawback that the life is short because the surfactant is gradually consumed.

[0004] Method 2 is an effective means depending on the application, but cannot be applied to glass requiring relatively large mechanical strength, such as automobiles and buildings.

[0005] Method 3 has been devised in order to achieve both anti-fog performance and mechanical strength, but all have limitations in terms of performance. Further, there is also a problem that the antifogging performance is remarkably deteriorated once the stain is attached.

Therefore, recently, an antifogging and antifouling article in which titanium oxide, which is an oxide semiconductor acting as a photocatalyst, is coated on the surface of a substrate has been proposed (Japanese Patent No. 2756474, Method 4). this is,
Titanium oxide on the surface of the glass absorbs ultraviolet light, and the energy of the ultraviolet light is used to efficiently oxidize and decompose organic substances adsorbed on the glass surface, thereby obtaining a clean surface having remarkable hydrophilicity. In addition to being composed entirely of inorganic materials, it has excellent mechanical strength.In addition, even if it becomes dirty, once it is exposed to ultraviolet light, the surface is cleaned again, the hydrophilic surface is restored, and the anti-fog property is improved. Recover.

As an example of an article having a hydrophilic surface using a photocatalyst such as titanium oxide, a mixture of a photocatalyst and silica (eg, Japanese Patent No. 2756474), a metal compound layer such as silica on a photocatalyst layer is provided. Those formed (for example, JP-A-10-231146, JP-A-9-57912, and JP-A-10-57817) have been proposed.

[0008] Japanese Patent Application Laid-Open No. 10-231146 discloses an anti-fogging method in which an alkali barrier film, a titanium oxide photocatalyst film, and an overcoat film are laminated in this order on the surface of a glass substrate, and the surface has irregularities. Glass articles are described.

[0009]

Although the method 4 has a feature which cannot be realized by other methods in principle, the intensity of the ultraviolet light inside the automobile and the building is very weak, so that the method 4 is put to practical use. Such anti-fog articles have not been obtained so far. In addition, the hydrophilicity maintaining performance of the surface rendered hydrophilic by ultraviolet irradiation (maintaining hydrophilicity after stopping the ultraviolet irradiation) is not sufficient, and particularly, the maintenance of the performance is not so good with respect to the antifogging property. There were also problems.

In view of the above prior art, the present invention expresses excellent hydrophilicity and antifogging property even in an environment where there is only weak ultraviolet light or visible light, and maintains good antifogging performance over a long period of time. Another object of the present invention is to provide an anti-fogging article having excellent anti-fogging performance that can be used for window glasses, mirrors, optical parts, glasses, and the like of buildings.

[0011]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that the addition of an iron compound to a photocatalytic film further improves the antifogging property. Was.

According to the present invention, there is provided an anti-fogging glass article having an alkali blocking film, a photocatalyst film, and an overcoat film laminated in that order on a surface of a glass substrate and having irregularities on the surface. Is 30% by weight of titanium oxide
As described above, the antifogging glass article is characterized by containing an iron compound in an amount of 0.001 to 10% by weight in terms of Fe.

In the present invention, the photocatalytic film is made of TiO.
₂, ZnO, SnO₂, SrTiO ₃, WO₃, Bi₂
O₃, Fe₂O₃, In₂O₃Such as metal oxide semiconductor
High catalytic activity and excellent physicochemical stability in the membrane
Titanium oxide (TiO₂) Are used, especially fine particles
Crystal form is preferably used.

The formation of the photocatalyst film is performed by using a usual thin film manufacturing method, and is not particularly limited. However, even if a photocatalytic film such as a titanium oxide film is directly coated on the glass substrate surface, high photocatalytic activity may not be obtained. This is because alkali metal ions such as Na ions diffused out of the glass substrate containing the alkali metal during the heat treatment combine with the titanium oxide and reduce the crystallinity of the titanium oxide in the film. It is. When a glass material containing an alkali metal is used as the base material, a silicon oxide film or another alkali blocking film is provided on the glass base material to prevent a decrease in the crystallinity of the titanium oxide film. Coating a photocatalytic film containing titanium oxide.

[Alkali barrier film] As the alkali barrier film, a film having a single component or a multicomponent composition selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide, zirconium oxide and cerium oxide is preferably used. Is done. Among these, a single component of silicon oxide (silica) or a multicomponent component whose main component is silicon oxide is preferable, and a two-component metal oxide of silicon oxide and zirconium oxide is more preferable. A metal oxide whose main component is silicon oxide has a low refractive index and can be formed without significantly deteriorating the optical characteristics of the glass plate. A two-component metal oxide of silicon oxide and zirconium oxide is preferably an alkali metal. The barrier performance is very high, so that it is more preferable. The content of zirconium oxide is particularly preferably from 1% by weight to 30% by weight. When the content is less than 1% by weight, the effect of improving alkali barrier performance is not so different from that of silicon oxide alone, and when the content is more than 30% by weight, the effect of improving alkali barrier performance is no longer improved, and the reflectance is increased by increasing the refractive index. This is not preferable because the tendency to occur is increased and it becomes difficult to control the optical characteristics of the glass plate.

The thickness of the alkali barrier film is preferably 5 nm or more and 300 nm or less. If the thickness is less than 5 nm, the alkali blocking effect is not sufficient, and 300 n
When the thickness is larger than m, interference colors due to the film become remarkable, and it becomes difficult to control the optical characteristics of the glass plate, which is not preferable.

The alkali barrier film can be formed by a known method. For example, the sol-gel method (for example, Yuji Yamamoto, Kanichi Kamiya, Saio Sakuhana, Journal of the Ceramic Society of Japan, 90, 328-333 (1
982)), liquid phase deposition method (for example, Japanese Patent Publication No. 1-5921)
0, Japanese Patent Publication 4-13301), vacuum film formation method (vacuum deposition,
Spattering), baking method, spray coating (for example, JP-A-53-124523, JP-A-56-96849), CV
Method D (for example, JP-A-55-90441, JP-A-1-201
046, JP-A-5-208849).

[Photocatalyst layer] The photocatalyst film in the present invention is produced by using a usual thin film production method, for example, a sol-gel method, a liquid phase deposition method (for example, Patent 2716244), a vacuum film formation method (vacuum deposition, sputtering). , Baking method, spray coat,
The CVD method can be exemplified.

As the photocatalytic film in the present invention, a film containing titanium oxide having high catalytic activity and excellent physicochemical stability is used. The content of titanium oxide in the film is 30% by weight or more. If the content of titanium oxide is less than 30% by weight, the photocatalytic activity is not sufficient, so that the rate of hydrophilization by light irradiation decreases, and as a result, the antifogging property is maintained. Performance improvement is not enough. Titanium oxide may be present in the film in either particulate or matrix form, or in both forms. The photocatalytic film is a titanium oxide crystal, preferably having a particle size of 4 to 300 nm, more preferably 10 to 10 nm.
It is preferable that fine particles of 0 nm are contained in an amount of 30% by weight or more. Examples of substances that can be contained in the photocatalytic film in addition to the iron compound and titanium oxide described above include silicon oxide, aluminum oxide, alkali metal, zirconium oxide, antimony oxide, amorphous oxide as a matrix or fine particles of the film. Metals or metal compounds having no photocatalytic activity, such as titanium and hydrous titanium oxide; GeO
₂ , ThO ₂ , ZnO, SnO ₂ , SrTiO ₃ , WO
₃ , metal oxides having photocatalytic activity such as Bi ₂ O ₃ and In ₂ O ₃ . Among these, it is preferable to add silicon oxide (matrix or fine particles) because the hydrophilicity is further improved.

The photocatalyst film of the present invention can be composed of fine particles and a matrix, and the matrix of the film is composed of titanium oxide, and the fine particles are composed of silicon oxide, aluminum oxide, zirconium oxide, cerium oxide and titanium oxide. Fine particles having a particle size of 4 to 300 nm made of at least one oxide selected from the group may be used.

The photocatalyst film of the present invention has a thickness of 100n.
When the thickness is from m to 300 nm, hydrophilicity due to weak ultraviolet irradiation is recognized, and high catalytic activity is exhibited.
If the thickness of the photocatalyst film is less than 100 nm, it is not preferable because hydrophilicity due to weak ultraviolet irradiation is hardly recognized. When the thickness is more than 300 nm, the photocarriers generated in the film cannot diffuse to the outer surface of the film, so that the photocatalytic activity is reduced. As a result, the anti-fogging performance is reduced, interference color is remarkably recognized, and the light resistance is improved. It is not preferable because the abrasion is reduced.

The photocatalyst film of the present invention contains an iron compound. The iron compound to be contained in the photocatalyst film may be any compound as long as it contains iron, but may be any of iron acetylacetonate compounds, chlorides, nitrates, acetates, carbonyl compounds, alkoxides, hydroxides, oxides, and the like. Is preferably used. Addition of the iron compound facilitates hydrophilicity by irradiating weak ultraviolet rays, and improves the performance of maintaining hydrophilicity. As a result, the antifogging property is improved. The addition amount of the iron compound in the photocatalytic film is 0.001% by weight or more and 10% by weight or less, preferably 0.004 to 7% by weight in terms of Fe. If less than 0.001% by weight,
The effect of adding the iron compound is not sufficient, and if it is more than 10% by weight, the film becomes brittle and the abrasion resistance decreases, and the film is undesirably colored. It is believed that the iron compound is present in the photocatalytic film in either particulate or matrix form or both. It is not clear why the iron compound facilitates hydrophilicization by weak UV irradiation and improves the performance of maintaining hydrophilicity, but it is presumed that the iron compound functions as an electron acceptor or that the iron compound is colored. You.

In the present invention, the photocatalyst film made of titanium oxide or the like or the photocatalyst film containing titanium oxide or the like is produced by using an ordinary thin film production method. Among them, the sol-gel method is preferably applied. The sol is obtained by simultaneously hydrolyzing a titanium alkoxide or a titanium alkoxide and another metal alkoxide. In addition, it is easy to use a commercially available liquid in which titanium oxide fine particles are dispersed in an inorganic binder (containing an alkoxide of a metal other than titanium),
It is preferably used. Examples of commercially available liquids include “ST-
K03 "(manufactured by Ishihara Sangyo Co., Ltd., titanium oxide fine particle diameter 20 to 30 nm, titanium oxide content 5% by weight, inorganic binder content 5% by weight) and" CA-62 "(manufactured by Taki Chemical Co., Ltd., titanium oxide Fine particle diameter 10-20 nm,
(A titanium oxide content of 6% by weight and a binder amount of 1.5% by weight). In particular, a method using a liquid in which titanium oxide fine particles are dispersed is preferable because a photocatalytic film containing titanium oxide fine particles having a particle diameter of 4 to 300 nm can be easily obtained.

After a titanium oxide-based thin film is formed on these alkali barrier films, a heat treatment is preferably performed at 450 to 650 ° C. for 10 minutes to 2 hours for densification and improvement of titanium oxide crystallinity. .

[Surface Irregularity of Photocatalyst Film] The surface irregularities in the antifogging glass article of the present invention are obtained by forming a photocatalytic film having an irregular surface on the surface of a glass substrate on which an alkali barrier film is formed, and then removing the irregularities. It can be manufactured by either a method of laminating a thin overcoat film so as not to be damaged or a method of making the overcoat film itself uneven.

The surface of the titanium oxide-based photocatalyst film is made uneven,
As a method of forming unevenness on the article surface of the present invention,
(A) a method of performing etching using plasma or hydrofluoric acid after forming a titanium oxide-based photocatalyst film, and (b) a method of forming a titanium oxide-based photocatalyst film by, for example, a sol-gel method. A method of adding or dispersing an organic polymer or organic polymer fine particles such as polystyrene or the like, followed by heat treatment. (C) For example, when a titanium oxide-based photocatalytic film is formed by a sol-gel method, a titanium alkoxide-based coating solution is used. A method of adding and dispersing, preferably, colloidal metal oxide fine particles (for example, titanium oxide fine particles, silicon oxide fine particles, aluminum oxide fine particles, zirconium oxide fine particles, and cerium oxide fine particles), and (d) a titanium oxide-based photocatalyst by, for example, a sol-gel method. When forming a film, a metal alkoxide other than titanium (for example, silicon Kishido, zirconium alkoxide, a method is preferably aluminum alkoxide) coating liquid of the principal adding dispersing metal oxide fine particles containing colloidal least titanium oxide particles, (e)
For example, when forming a titanium oxide film by a sol-gel method,
When preparing a coating solution containing titanium alkoxide or its hydrolyzate, polycondensation reaction of titanium alkoxide is promoted by adding an alkali, increasing the amount of added water, or reducing the amount of a stabilizing agent. And the like.

Of these methods, the method (a) is not preferable because the number of steps increases, and the method (d) deteriorates the film quality of the titanium oxide film, lowers the mechanical strength and lowers the transparency. Or the photocatalytic activity may be reduced, which is not preferred. Method (b), Method (c)
The method (d) is preferably used because the uneven titanium oxide film can be obtained relatively easily.

The metal oxide fine particles used in the above method (b), method (c) or method (d) include silicon oxide (silica), aluminum oxide (alumina), zirconium oxide (zirconia), and titanium oxide (titania). ),
Single component metal oxide fine particles selected from the group consisting of cerium oxide (ceria), mixtures thereof, and composite metal oxide fine particles composed of two or more of these components are used. These are preferably used in the form of a solvent dispersion sol. As the metal oxide sol, for example, in the case of silica sol, “Snowtex-
OL, Snowtex-O, Snowtex-
OUP "," Snowtex-UP ", and alumina sols such as" Alumina Sol 520 "manufactured by Nissan Chemical Industries, Ltd.
Commercially available water dispersion such as "Zirconia Sol NZS-30A" manufactured by Nissan Chemical Industry Co., Ltd. for zirconia sol, "Titania Sol CS-N" manufactured by Ishihara Sangyo Co., Ltd. for titania sol, and "Needral U-15" manufactured by Taki Chemical Co., Ltd. for ceria sol In addition to the sol, "IPA-S" manufactured by Nissan Chemical Industries, Ltd.
T "and silica sol dispersed in a commercially available organic solvent such as" XBA-ST "manufactured by the same company.

The size of the metal oxide fine particles is 4
~ 300 nm is preferred. When the particle size is less than 4 nm, the arithmetic average roughness (Ra) tends to be less than 0.5 nm, and the average interval (Sm) of the irregularities tends to be less than 4 nm, so that the anti-fogging property, anti-fogging durability and hydrophilicity retention are improved. It is not preferable because no effective unevenness can be formed. When the particle size exceeds 300 nm, the arithmetic average roughness (Ra) becomes larger than 100 nm, and the average interval (Sm) of the irregularities exceeds 300 nm. It is not preferable because the fine particles tend to settle.

As the metal oxide fine particles, chain fine particles are preferable. By using chain-shaped fine particles, usually colloidal chain fine particles, the surface unevenness becomes a three-dimensionally intricate uneven shape, and the anti-fogging property, anti-fogging durability and hydrophilicity maintenance property are improved respectively. It is possible to form a roughened surface. Examples of chain colloids include chain silica sols (“Snowtex-OUP” and “Snowtex-UP” manufactured by Nissan Chemical Industries, Ltd.),
They have a diameter of 10-20 nm and a length of 40-300 nm.

According to the above method (c), 1) an uneven thin film made entirely of titanium oxide, 2) an uneven thin film in which other metal oxide fine particles are dispersed in a matrix mainly made of titanium oxide, and 3) An uneven thin film in which titanium oxide fine particles and other metal oxide fine particles are dispersed in a matrix mainly composed of titanium oxide is obtained.

According to the above method (d), 1) an uneven thin film in which titanium oxide fine particles are dispersed in a matrix made of a metal oxide other than titanium oxide, and 2) a matrix made of a metal oxide other than titanium oxide An uneven thin film in which titanium oxide fine particles and other metal oxide fine particles are dispersed is obtained.

[Overcoat film] In the present invention,
An overcoat film made of a hydrophilic metal oxide is formed on the photocatalyst film.

The overcoat film is at least one metal oxide selected from silicon oxide, aluminum oxide, zirconium oxide, cerium oxide and titanium oxide, and is preferably a thin film containing silicon oxide in an amount of 50% by weight or more. However, a metal oxide composed of 100% titanium oxide crystals is not preferable because it does not have hydrophilicity.

The coating of the overcoat film is made by using a known thin film manufacturing method.
A liquid phase deposition method, a baking method / spray coating, a CVD method and the like can be exemplified, but a sol-gel method is preferably used because the surface unevenness of the overcoat film can be easily adjusted.

As a method for forming the overcoat film, a group consisting of a hydrolyzable / polycondensable organometallic compound, a chlorosilyl group-containing compound, and a hydrolyzate thereof, each of which can form a hydrophilic metal oxide. Examples of the method include forming a liquid obtained by adding hydrophilic metal oxide fine particles to a liquid containing at least one selected from the above, and applying the liquid on the substrate on which the photocatalytic film is formed.

In the above-mentioned method, at least one selected from the group consisting of a hydrolyzable / polycondensable organometallic compound, a chlorosilyl group-containing compound and a hydrolyzate thereof is used as the hydrophilic metal oxide forming the overcoat film. It serves as a product matrix and holds the hydrophilic metal oxide fine particles in the film.

The hydrophilic metal oxide matrix constituting the overcoat film may be at least one metal oxide selected from silicon oxide, aluminum oxide, cerium oxide, zirconium oxide and amorphous titanium oxide. Preferably, more preferably, 50% by weight of silicon oxide
The above is included. When silicon oxide is contained in an amount of 50% by weight or more, the effect of improving hydrophilicity is remarkable.

In the above forming method, the hydrolyzable / polycondensable organometallic compound capable of forming a hydrophilic metal oxide is an organometallic compound of silicon, aluminum, titanium, zirconium or cerium. . Further, as the hydrophilic oxide fine particles, a single component metal oxide fine particles selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, and cerium oxide, a mixture thereof, and two or more kinds thereof The composite metal oxide fine particles composed of the following components are used. These are preferably used in the form of a solvent dispersion sol (colloid solution). However, a combination of an organometallic compound of titanium and titanium oxide fine particles is inappropriate because the resulting metal oxide does not exhibit hydrophilicity.

Examples of the solvent dispersion sol of the metal oxide include “Snowtex-OL”, “Snowtex-O”, and silica sol manufactured by Nissan Chemical Industries, Ltd.
"Snowtex-OUP", "Snowtex-U"
P "and the company's alumina sol" Alumina Sol 520 ",
The company's zirconia sol "NZS-30A", Ishihara Sangyo Co., Ltd. titania sol "CS-N", "STS-0"
1 "," STS-02 ", Teria Chemical Co., Ltd. ceria sol" Needral U-15 ", titania sol" M-6 "
Commercially available water-dispersed sols such as "IPA-ST" and "XBA-ST" manufactured by Nissan Chemical Industries, Ltd .;
Commercially available water-alcohol mixed solvent-dispersed titania sol containing a binder, such as "1" and "ST-K03".

The particle size of the hydrophilic metal oxide fine particles is preferably from 4 nm to 300 nm. By using fine particles having a particle diameter in this range, the surface unevenness after the formation of the overcoat film becomes an appropriate value, and the performance of maintaining hydrophilicity is further improved. Further, when fine particles smaller than 4 nm are used, the improvement in hydrophilicity is not so large, which is not preferable. When fine particles larger than 300 nm are used, the transparency tends to be impaired due to the formation of an overcoat film, which is not preferable.

As the hydrophilic metal oxide fine particles, chain fine particles are preferable. By using the chain-shaped fine particles, the overcoat film has a three-dimensionally intricate uneven surface, so that a surface unevenness with high antifogging performance and antifogging durability can be formed. When it is desired to form irregularities having the arithmetic mean roughness (Ra) and the average interval (Sm) of irregularities of the surface described later by the irregularities of the overcoat film itself, the chain fine particles can be easily used. This unevenness can be preferably formed. Examples of chain colloids include "Snowtex-OUP" and "Snowtex-UP", which are silica sols manufactured by Nissan Chemical Industries, Ltd., and these are 10 to 20 n.
m and a length of 40-300 nm.

The metal oxide fine particles are preferably contained in the overcoat film in an amount of 5% by weight or more and 80% by weight or less. If the amount is less than 5% by weight, the above-mentioned preferable uneven shape cannot be provided, which is not preferable. 80% by weight
If the amount is larger, the overcoat film becomes brittle, and the abrasion resistance decreases, which is not preferable.

The dispersion solvent of the metal oxide fine particles is not particularly limited as long as the metal oxide fine particles are substantially stably dispersed, but is preferably a simple substance or a mixture of water, methanol, ethanol, propanol and the like. Water is more preferred. These water and lower alcohol may be easily mixed with the solution containing the organometallic compound, and may be easily removed by drying during film formation or heat treatment after film formation. Of these, water is the most preferable in the production environment.

When the metal oxide fine particles are added to the solution containing the organometallic compound or the chlorosilyl group-containing compound, a dispersing aid may be added. The dispersing aid is not particularly limited, and is generally used as a dispersing aid, for example, electrolytes such as sodium phosphate, sodium hexametaphosphate, potassium pyrophosphate, aluminum chloride, and iron chloride;
Various surfactants, various organic polymers, silane coupling agents, titanium coupling agents and the like are used. The addition amount is usually 0.01 to 5 with respect to the metal oxide fine particles.
% By weight.

Hydrolyzable and polycondensable organometallic compounds capable of forming a hydrophilic metal oxide to be contained in a coating solution for forming an overcoat film together with the above-mentioned metal oxide fine particles are hydrolyzed and dehydrated and condensed. Basically, any compound may be used as long as it performs the above, but metal alkoxides and metal chelates are preferred.

As the metal alkoxide, specifically, methoxide such as silicon, aluminum, zirconium and titanium, ethoxide, propoxide, butoxide and the like are preferably used alone or as a mixture. As the metal chelate, an acetylacetonate complex such as silicon, aluminum, zirconium, and titanium is preferably used.

As the silicon alkoxide, a high molecular weight type alkyl silicate such as “Ethyl Silicate 40” manufactured by Colcoat Co., Ltd.
S56 "can also be used. As a hydrolyzate of silicon alkoxide, commercially available alkoxysilane hydrolyzate such as “HAS-1” manufactured by Colcoat Co., Ltd.
0 ", Nippon Laboratories Inc." Ceramica G-91 ",
“Ceramica G-92-6”, “Atron NSI-500” manufactured by Nippon Soda Co., Ltd. and the like can be used.

The compound containing a chlorosilyl group, which is capable of forming a hydrophilic metal oxide and is contained in a coating solution for forming an overcoat film together with the fine particles of a hydrophilic metal oxide, is a chlorosilyl group (—SiCl _n X _3-n , wherein n is 1, 2, or 3, X is hydrogen, or an alkyl or alkoxy group having 1 to 10 carbon atoms,
Or an acyloxy group) in the molecule.
Compound. Among them, compounds having at least two chlorine atoms are preferable, and silane Si _n H
Chlorosilanes in which at least two hydrogens in _{2n + 2} (where n is an integer of 1 to 5) are substituted with chlorine and other hydrogens are optionally substituted with the above alkyl, alkoxy or acyloxy group, And polycondensates thereof are preferred.

For example, tetrachlorosilane (silicon tetrachloride, SiCl ₄ ), trichlorosilane (SiHC)
l ₃ ), trichloromonomethylsilane (SiCH ₃ Cl)
₃ ), dichlorosilane (SiH ₂ Cl ₂ ), and Cl
— (SiCl ₂ O) n —SiCl ₃ (n is an integer of 1 to 10) and the like. Hydrolysates of the above-mentioned chlorosilyl group-containing compounds can also be used, and from these, they can be used alone or in combination of two or more. The most preferred compound containing a chlorosilyl group is tetrachlorosilane. Since the chlorosilyl group has very high reactivity, a dense film can be formed by self-condensation or condensation reaction with the substrate surface.

The solvent of the solution containing the above-mentioned organometallic compound or chlorosilyl group-containing compound or a hydrolyzate thereof can be basically used if the above-mentioned organometallic compound or chlorosilyl group-containing compound or a hydrolyzate thereof is substantially dissolved. Anything. Specifically, alcohols such as methanol, ethanol, propanol, and butanol are most preferable, and the total of the above-mentioned organometallic compound, chlorosilyl group-containing compound, and their hydrolyzate is contained at a concentration of 1 to 30% by weight. it can.

Water is required for the hydrolysis of the organometallic compound. This may be either acidic or neutral, but in order to promote hydrolysis, water made acidic with hydrochloric acid, nitric acid, sulfuric acid, acetic acid, citric acid, sulfonic acid or the like having a catalytic action is preferably used. .

The amount of water required for the hydrolysis of the above-mentioned organometallic compound is 0.1 to 10 mol per mol of the organometallic compound.
100 is good. If the amount of water added is less than 0.1 in molar ratio, the promotion of hydrolysis of the organometallic compound is not sufficient, and if the amount is more than 100, the stability of the liquid tends to decrease, which is not preferable.

The amount of the acid added is not particularly limited, but is preferably 0.001 to 20 in terms of a molar ratio with respect to the organometallic compound. If the amount of the added acid is less than 0.001 in molar ratio, the promotion of the hydrolysis of the organometallic compound is not sufficient, which is not preferable, and if it is more than 20, the acidity of the solution becomes too strong,
It is not preferable in handling. From the viewpoint of hydrolysis alone,
The upper limit of the amount of the added acid is 2 in a molar ratio with respect to the organometallic compound.
It is.

When the chlorosilyl group-containing compound is used, it is not always necessary to add water or an acid. Even if no additional water or acid is added, hydrolysis proceeds due to moisture contained in the solvent or moisture in the atmosphere.
In addition, hydrochloric acid is released into the liquid with the hydrolysis, and the hydrolysis further proceeds. However, it does not matter if water or acid is additionally added.

The above-mentioned metal oxide fine particles and the above-mentioned organometallic compound, chlorosilyl group-containing compound or a hydrolyzate thereof are mixed with a solvent, and if necessary, water, an acid catalyst,
By adding a dispersing aid, a coating solution for forming an overcoat layer on the substrate can be prepared. At this time, the organometallic compound and the chlorosilyl group-containing compound may be used alone or as a mixture. The preferred raw material mixing ratio of this coating liquid is as shown in Table 1 below.

[0057]

[Table 1] Organometallic compounds or chlorosilyl group-containing compounds or their compounds Hydrolyzate 100 parts by weight Metal oxide fine particles 10 to 200 parts by weight Water 0 to 150 parts by weight Acid catalyst 0 to 35 parts by weight Dispersing aid 0.001 to 10 parts by weight Solvent 500 to 300,000 parts by weight ──────────────────────────────

The above organometallic compound or chlorosilyl group-containing compound is dissolved in a solvent, a catalyst and water are added, and the mixture is hydrolyzed at a predetermined temperature between 10 ° C. and the boiling point of the solution for 5 minutes to 2 days. The metal oxide fine particles and a dispersing aid are added thereto as needed, and the mixture is further reacted at a predetermined temperature between 10 ° C. and the boiling point of the solution for 5 minutes to 2 days as needed. obtain.

When a chlorosilyl group-containing compound is used, it is not necessary to add a catalyst and water.
The metal oxide fine particles may be added before the hydrolysis step. Further, in order to omit the step of hydrolyzing the organometallic compound, the above-mentioned commercially available hydrolyzate of the organometallic compound may be used. The obtained coating liquid may be subsequently diluted with an appropriate solvent according to the coating method.

The above coating liquid for forming an overcoat film is coated on a photocatalytic film made of titanium oxide or the like and dried,
Heat treatment can be performed as needed to form a hydrophilic metal oxide layer on the photocatalytic film.

The coating method may be a known one, and is not particularly limited. Examples thereof include a method using an apparatus such as a spin coater, a roll coater, a spray coater, and a curtain coater, a dipping and pulling method (dip coating method), A method such as a flow coating method (flow coating method) and various printing methods such as screen printing, gravure printing, and curved surface printing are used.

The coated substrate is dried at a temperature between room temperature and 150 ° C. for 1 minute to 2 hours, and then dried at 150 ° C. if necessary.
It is preferable to perform a heat treatment at a temperature between the temperature and the heat resistant temperature of the substrate for 5 seconds to 5 hours.

The substrate heat resistance temperature is the upper limit temperature at which the properties of the substrate can be substantially maintained.
For example, a softening point and a devitrification temperature (normally 600 to 700 ° C.) are exemplified.

By the drying and heat treatment, a hydrophilic overcoat film can be formed on the photocatalyst film surface. This overcoat film is composed of a matrix (or binder) of hydrophilic metal oxide fine particles and a hydrophilic metal oxide (derived from an organometallic compound or a compound containing a chlorosilyl group). The film form is (1) an island-like or hole-like film or network with a metal oxide matrix gathered around metal oxide fine particles, and the photocatalytic film is not completely covered but is partially exposed. (2)
There are two types in which the metal oxide fine particles and the metal oxide matrix cover the photocatalytic film extremely thinly. In the present invention, either of these two types may be used.

The article in which the metal oxide overcoat film is formed on the surface of the photocatalyst film in this manner has improved water wettability, a small contact angle of water droplets, and has anti-fog performance. Further, the contact angle does not easily increase even if the surface is slightly stained, and the antifogging property is maintained.

The thickness of the overcoat film is preferably from 0.1 to 50 nm on average, more preferably from 1 to 20 nm. If the average thickness is less than 0.1 nm, the effect of the overcoat is low, that is, the hydrophilic property is not improved, which is not preferable. If the average thickness is larger than 50 nm, the photocatalytic activity of the photocatalytic film is reduced, and the dirt component attached to the surface cannot be decomposed by light irradiation, which is not preferable. If the thickness is less than 1 nm, the antifogging durability tends to decrease, and if it is more than 20 nm, the abrasion resistance tends to decrease, and both are not preferred.

The surface unevenness of the overcoat film preferably has an arithmetic average roughness (Ra) of 0.5 to 100 nm and an average interval (Sm) of the unevenness of 4 to 300 nm. If the Ra value is smaller than 0.5 nm or larger than 100 nm, the antifogging performance and the antifogging durability are low, which is not preferable. Also, even if the Sm value is smaller than 4 nm,
Even if it is larger, the anti-fog performance and anti-fog persistence are still low,
Not preferred. Especially when the Sm value is larger than 300 nm,
This is not preferable because transparency is impaired. The surface unevenness of the overcoat film of the present invention more preferably has an arithmetic average roughness (Ra) of 5 to 30 nm and an average interval (Sm) of unevenness of 5 to 150 nm. Within this range, the antifogging performance, especially the antifogging durability, is further improved.

Here, the Ra value and the Sm value are based on JIS B
0601 (1994) and an atomic force microscope (for example, SPI3 manufactured by Seiko Instruments Inc.)
700) or an electron microscope (for example, H-600 manufactured by Hitachi, Ltd.).

[0069]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited to these embodiments.

Example 1, Comparative Example 1 [Formation of Alkali Barrier Layer (Silica Film)] Hydrolysis of 96.2 parts by weight of alcohol (trade name: AP-7, manufactured by Nippon Kaseihin Co., Ltd.) and ethyl silicate Polycondensation liquid (trade name: H
AS-10, manufactured by Colcoat Co., Ltd., silica content 10
3.8% by weight) was mixed at room temperature and stirred for 1 hour to obtain a coating liquid for forming an alkali-blocking silica film.

A soda lime silicate glass plate (150 × 150 × 3 mm) which has been polished and washed with a cerium oxide-based abrasive, further ultrasonically cleaned in pure water, and dried is used.
The suspension was suspended vertically in an environment of 30 ° C. and 30% RH, and the coating solution for forming an alkali-blocking silica film was flowed from the upper end of the glass plate to coat the film on one surface of the glass plate (flow coating method). 100 pieces of this glass plate
After drying at 250 ° C. for 30 minutes, and further drying at 250 ° C. for 30 minutes, a heat treatment was performed in a 500 ° C. oven for 1 hour to obtain a glass substrate on which an alkali-blocking silica film having a thickness of about 30 nm was formed.

[Formation of photocatalyst layer (silica fine particle-dispersed iron-added titania film)] 1-butanol, ethanol and 2-
A mixture of propanol at a weight ratio of 10: 9: 1 was used as a solvent. 2.40 g of the above solvent was added to 0.10 g of iron acetylacetone and dissolved to prepare an iron-added liquid. 173.49 g of the above solvent, silica colloid (trade name: IPA)
-ST-S, manufactured by Nissan Chemical Industries, Ltd., particle size 10 to 2
0 nm, silica content 25.5% by weight) 3.15 g, titania sol (trade name: Atron Nti-500, manufactured by Nippon Soda Co., Ltd., titania content 5% by weight) 20.16
g, silica sol (trade name: Rixon coat CSG-b1)
-0600, manufactured by Chisso Corporation, silica content 6 wt%) 3.15 g and the above-mentioned iron-added liquid 0.80 g were mixed,
The coating solution was obtained by stirring at room temperature for about 1 hour.

The above-mentioned glass substrate with an alkali-blocking silica film is suspended vertically in an environment of 20 ° C. and 30% RH, and the coating solution for forming a photocatalyst layer is flowed from the upper end of the substrate. The photocatalyst layer was coated (flow coating method). After drying at room temperature for 30 minutes, and further drying at 220 ° C. for 10 minutes, coating and drying are repeated once to obtain a thickness of about 220
A glass substrate on which a photocatalyst layer of nm was formed was obtained. The obtained sample is referred to as Sample A (glass substrate / alkali blocking silica film / silica fine particle-dispersed iron-added titania film).
A sample obtained by holding this sample A at 625 ° C. for 2 minutes and firing was designated as sample A ′ (Comparative Example 1).

The photocatalyst layer of sample A ′ contained 50% of titanium oxide and 0.25% of iron with respect to the unit weight of the film. As a result of analysis by X-ray diffraction, it was confirmed that the titanium oxide in the photocatalyst layer of Sample A ′ was an anatase crystal. The thickness of the photocatalyst layer of Sample A ′ measured by an electron microscope was about 200 nm. In addition, as a result of measurement with an atomic force microscope, the surface of Sample A ′ was a smooth surface having an arithmetic average roughness (Ra) of less than 0.2 nm and an average interval (Sm) of irregularities of 600 nm.

[Formation of Overcoat Layer (Silica Film)]
A silica overcoat layer was formed on Sample A by the method described below. 99.1 g of ethanol, a hydrolytic condensation polymerization solution of ethyl silicate (trade name: HAS-10,
0.7 g of Colcoat Co., Ltd., solid content 10% by weight)
0.2 g of chain silica colloid (average diameter: about 15 nm, average length: about 170 nm, trade name: Snowtex OUP, manufactured by Nissan Chemical Co., Ltd., solid content: 15% by weight) is mixed and stirred at room temperature for about 1 hour. Thus, a coating liquid was obtained.

The sample A substrate was suspended vertically in an environment of 20 ° C. and 30% RH, and the coating liquid for forming the overcoat layer was flowed from the upper end of the substrate to coat the overcoat film on the photocatalytic layer of the substrate. (Flow coating method). Thereafter, by performing a heat treatment at 625 ° C. for 2 minutes, a sample B (glass substrate / alkali blocking silica film / iron-added silica fine particle-dispersed titania-silica film / silica overcoat layer: Example 1) was obtained. In the photocatalyst layer of sample B (iron-added silica fine particle-dispersed titania-silica film), 50 parts of titanium oxide were added to the unit weight of the film.
%, And iron at a rate of 0.25%. And X
As a result of analysis by line diffraction, it was confirmed that titanium oxide in the photocatalyst layer of Sample B was an anatase crystal.
The thickness of the photocatalyst layer of Sample B measured by an electron microscope was about 200 nm. As a result of the measurement with an atomic force microscope, the surface of the sample B had an arithmetic average roughness (Ra).
Is 10 nm and the average interval (Sm) of the irregularities is 50 n.
m. The average thickness of this silica overcoat layer determined by ESCA was about 5 nm.

[Evaluation of anti-fogging property] Samples A 'and B
Is kept in a room where no direct sunlight is applied but indirectly bright with sunlight, and people constantly come in and out of the room, and the degree to which the surface becomes dirty and the anti-fog property decreases, the degree of cloudiness when exhalation is blown (Respiratory test). That is, the sample immediately after the surface is cleaned does not fog even when breath is blown, but when left indoors, the dirt component in the air is adsorbed on the sample surface and becomes cloudy by the breath test. The time from the start of indoor standing until the start of fogging (antifogging maintenance time) was used as an index of antifogging maintenance. It can be said that the larger this value is, the higher the antifogging maintenance property is. The antifogging maintenance of these samples was evaluated according to Table 2 below.

Further, an ultraviolet cut filter L-42 (manufactured by Toshiba Glass Co., Ltd., having a transmittance of 0% at a wavelength of 390 nm or less, a wavelength of 0%, 5% transmittance at 400 nm, about 50% transmittance at 420 nm, 450 wavelength
xenon lamp light (UV intensity in the absence of an UV cut filter) from the film surface over about 80% transmittance of about 80 nm and about 90% of visible light having a wavelength of 520 nm or more.
5mW / cm2: UV intensity meter U manufactured by Topcon Corporation
Measured with VR-2 / UD-36. ) Was continuously irradiated for one hour, and the magnitude of the decrease in the contact angle of the water droplet was used as an index of the anti-fogging recovery property. In addition, an ultraviolet ray of 0.5 mW / cm2 (340 to 3
95 nm) The irradiation intensity corresponds to about 20% of the ultraviolet light intensity included in direct sunlight from outdoor sunlight at 35 degrees north latitude at noon in winter, fine weather, and noon. If the contact angle of a water drop is reduced by the light (visible light and weak ultraviolet light) obtained by cutting the ultraviolet light, it can be said that the sample has a very good antifogging recovery property. Contact angle meter (CA- manufactured by Kyowa Interface Science Co., Ltd.
DT ") before and after 1 hour light irradiation.
The contact angle with respect to a 4 mg water droplet was measured, and how much the contact angle was reduced by light irradiation was determined by (cosine of contact angle after light irradiation for 1 hour-1) / (cosine of contact angle before light irradiation- 1)
Was determined, and the antifogging recovery property was evaluated according to Table 3 below. It can be said that the smaller the water contact angle factor, the better the anti-fogging recovery property by light irradiation.

[0079]

[Table 2] ──────────────────────────── Evaluation Anti-fog retention period ──────────── ◎ ◎ No fogging or slight unevenness continues for 9 days or more ○ 6 days to less than 9 days △ 3 days to less than 6 days × less than 3 days ─ ───────────────────────────

[0080]

[Table 3] ────────────────────────────── Anti-fogging recovery property Evaluation of water droplet contact angle factor (1 hour after light irradiation) Cosine of contact angle of waterdrop-1 / cosine of contact angle of waterdrop before irradiation-1) ────────────────────────────── ◎ Less than 0.1 ○ 0.1 or more and less than 0.3 △ 0.3 or more and less than 0.5 × 0.5 or more ─────────────────────── ───────

[Evaluation of Abrasion Resistance] A flannel cloth was pressed against the surface of a sample with a pressure of 500 g / cm 2 and reciprocated 100 times with a stroke of 15 cm. Observation was made to evaluate “○”, “△” and “X” according to the following criteria. The results are shown in Table 4. ○ --- The film is not damaged at all and no peeling occurs. Δ --- The film is damaged, but no peeling occurs. C: The film is scratched and partially peeled off.

Table 4 shows the results of various evaluations of the samples A ′ (Comparative Example 1) and B (Example 1). It is clear that Sample B (Example 1) has better antifogging properties than Sample A '(Comparative Example 1). The samples A ′ (Comparative Example 1) and B (Example 1) both had good wear resistance.

[Example 2] [Formation of overcoat layer (titania-silica film)] On sample A prepared in Example 1, a method described below was used.
An overcoat layer was formed. Ethanol 498.21
1.34 g of tetrachlorosilane and colloid of titania (trade name: CS-N, manufactured by Ishihara Sangyo Co., Ltd., particle size: 30 g)
.About.60 nm, titania content: 30% by weight) and stirred at room temperature for about 1 hour to obtain a coating liquid.
The coating solution was applied onto Sample A in the same manner as described in Example 1 and heat-treated at 350 ° C. for 30 minutes to obtain Sample C (glass substrate / alkali blocking silica film / silica fine particle-dispersed iron-added titania film / A silica overcoat thin film) was obtained. As a result of measurement with an atomic force microscope, the surface of sample C had an arithmetic average roughness (Ra) of 3
The uneven surface was 0 nm and the average interval (Sm) of the unevenness was 50 nm. The average thickness of this overcoat layer was found to be about 10 nm by ESCA.
Met.

Table 4 shows the results of various antifogging performance evaluations of Sample C.
Shown in It is clear that the anti-fog performance is excellent. The abrasion resistance was also good.

Example 3 [Formation of Photocatalyst Layer (Silica Fine Particle-Dispersed Iron-Added Titania Thin Film)] 1.0 g of iron acetylacetone was dissolved in 24.0 g of alcohol (trade name: AP-7, manufactured by Nippon Kaseihin Co., Ltd.). This was used as an iron-added liquid. Alcohol (trade name: AP-7,
To 189.45 g of Nippon Kaseihin Co., Ltd., 2.53 g of acetylacetone (AcAc) and 3.59 g of titanium tetraisopropoxide (Ti (OiPr) ₄ ) were added, stirred, and further colloidal silica (trade name: IPA-ST) Manufactured by Nissan Chemical Industries, Ltd., particle diameter 10 to 20 nm, silica content 30% by weight) 3.31 g and the iron-added liquid 0.80
g was added and stirred at room temperature for about 1 hour to obtain a coating liquid. Sample D (glass substrate / alkali-blocking silica film / glass substrate) was applied on the glass substrate with an alkali-blocking film prepared in Example 1 by the same method as described in Example 1.
A silica fine particle-dispersed iron-added titania thin film) was obtained. A sample obtained by holding this sample D at 625 ° C. for 2 minutes and firing it is referred to as sample D ′ (Comparative Example 2). This photocatalyst layer contains titanium oxide in an amount of 6% based on the unit weight of the film.
4% and iron at a rate of 6.4%. As a result of analysis by X-ray diffraction, it was confirmed that the titanium oxide in the photocatalyst layer of Sample D ′ was an anatase crystal. The thickness of the photocatalyst layer of Sample D 'was about 200 nm. Further, as a result of measurement by an atomic force microscope, the surface of the sample D ′ was a surface having an arithmetic average roughness (Ra) of less than 2 nm and an average interval (Sm) of irregularities of 200 nm.

[Formation of Overcoat Layer (Silica Film)]
A silica overcoat layer was formed on Sample D by the method described below. 280 g of ethanol, 0.7 g of a hydrolytic condensation polymerization solution of ethyl silicate (trade name: HAS-10, manufactured by Colcoat Co., Ltd., silica content 10% by weight),
0.5 g of chain silica colloid (average diameter about 15 nm, average length about 170 nm, trade name: Snowtex OUP, manufactured by Nissan Chemical Co., Ltd., solid content 15% by weight) is mixed and stirred at room temperature for about 1 hour. Thus, a coating liquid was obtained. The sample D substrate was vertically suspended in an environment of 20 ° C. and 30% RH, and the coating liquid for forming the overcoat layer was flowed from the upper end of the substrate, and an overcoat film was coated on the photocatalyst layer of the substrate (flow Coating method). Thereafter, heat treatment was performed at 500 ° C. for 1 hour to obtain Sample E (glass substrate / alkali blocking silica film / silica fine particle-dispersed iron-added titania thin film / silica overcoat layer: Example 3). As a result of measurement with an atomic force microscope, the surface of sample E was found to have an arithmetic average roughness (Ra).
Is 12 nm and the average interval (Sm) between the irregularities is 40 n.
m. The average thickness of this silica overcoat layer determined by ESCA was about 5 nm.

Table 4 shows the results of evaluating various antifogging performances of Sample E.
Shown in It is clear that the anti-fog performance is excellent. The abrasion resistance was also good.

[Example 4, Comparative Example 2] [Formation of photocatalyst layer (iron-added silica film with titania fine particles dispersed therein)] Alcohol (trade name: AP-7, manufactured by Nippon Kasei Chemical Co., Ltd.) was added to 0.10 g of iron acetylacetone. .40 g was added and dissolved to obtain an iron-added liquid. Alcohol (product name: AP
-7, manufactured by Nippon Kaseihin Co., Ltd.) 184.61 g of titania colloid (trade name: ST-K01, manufactured by Ishihara Sangyo Co., Ltd., content of titania 8% by weight, content of silica 2% by weight)
12.46 g, 2.11 g of tetrachlorosilane and 0.79 g of the above-mentioned iron-added solution were added, and the mixture was stirred at room temperature for about 1 hour to obtain a coating solution. On the glass substrate provided with an alkali barrier film prepared in Example 1, it was applied in the same manner as described in Example 1 except that it was dried only at room temperature, and a thickness of about 2
A glass substrate on which a 50 nm photocatalytic layer was formed was obtained. The obtained sample is referred to as sample F (glass substrate / alkali-blocking silica film / titania fine particle-dispersed iron-added silica film). A sample obtained by subjecting this sample F to a heat treatment at 500 ° C. for 1 hour is referred to as a sample F ′ (Comparative Example 2). This photocatalytic layer contained 50% of titanium oxide and 0.25% of iron with respect to the unit weight of the film.
As a result of analysis by X-ray diffraction, it was confirmed that the titanium oxide in the photocatalyst layer of Sample F ′ was an anatase crystal. According to the measurement by the electron microscope, the sample F ′
The thickness of the photocatalyst layer was about 250 nm. In addition, as a result of measurement with an atomic force microscope, the surface of the sample F ′ was an uneven surface having an arithmetic average roughness (Ra) of 3 nm and an average interval (Sm) of unevenness of 300 nm.

[Formation of Overcoat Layer (Silica Film)]
The silica overcoat layer described in Example 1 was formed on Sample F by the method described in Example 1. This sample is referred to as Sample G (glass substrate / alkali blocking silica film / titania fine particle-dispersed iron-added silica film / silica overcoat thin film: Example 4). As a result of measurement with an atomic force microscope, the surface of the sample G had an arithmetic average roughness (Ra) of 14
The surface was an irregular surface having an average spacing (Sm) of 45 nm. The average thickness of this silica overcoat layer was found to be about 10 by ESCA.
nm.

Table 4 shows the results of evaluating various antifogging performances of the samples F ′ (Comparative Example 2) and G (Example 4). It is clear that Sample G (Example 4) has better anti-fog performance than Sample F '(Comparative Example 2). Regarding the abrasion resistance, both Sample G (Example 4) and Sample F ′ (Comparative Example 2) were good.

[Example 5] [Formation of photocatalyst layer (silica film with titania fine particles and silica fine particles dispersed iron added thereto)] Alcohol (trade name: AP-7, manufactured by Nippon Kaseihin Co., Ltd.) was added to 0.50 g of iron acetylacetone. Then, 00 g was added and dissolved to obtain an iron-added liquid. Alcohol (product name: AP-7, manufactured by Nippon Kaseihin Co., Ltd.) 1
83.28 g of titania colloid (trade name: ST-K0)
1. Ishihara Sangyo Co., Ltd., 5.63 g of titania content 8% by weight, silica content 2% by weight and colloidal silica colloid (average diameter about 15 nm, average length about 170 nm, trade name: Snowtex OUP, Nissan) 2.00 g of solid content 15% by weight (manufactured by Chemical Co., Ltd.) and 1.6 of tetrachlorosilane
1 g and the above-mentioned iron-added liquid (7.33 g) were added, and the mixture was stirred at room temperature for about 1 hour to obtain a coating liquid. Except for drying at room temperature on the glass substrate provided with an alkali blocking film prepared in Example 1,
Sample H (glass substrate / alkali-blocking silica film / titania fine particles and silica fine particle-dispersed silica-added silica film) was obtained by applying the solution once and heat-treating at 500 ° C. for 1 hour. This photocatalyst layer contains 30% of titanium oxide fine particles, 3.1% of iron, and 20% of silica fine particles based on the unit weight of the film.
%. As a result of analysis by X-ray diffraction, it was confirmed that the titanium oxide in the photocatalyst layer of Sample H was an anatase crystal. The thickness of the photocatalyst layer of Sample H was about 190 nm. As a result of measurement by an atomic force microscope, the surface of the sample H had an arithmetic average roughness (Ra) of 4 nm and an average interval of irregularities (Sm).
Had an uneven surface of 50 nm.

[Formation of Overcoat Layer (Silica Film)]
A silica overcoat layer was formed on Sample H by the method described below. Hydrolysis-condensation polymerization solution of ethyl silicate (trade name: HAS) in 199.87 g of 2-propanol
-10, manufactured by Colcoat Co., Ltd., 0.10 g of silica content 10% by weight and silica colloid (trade name: IPA-S)
T, manufactured by Nissan Chemical Industries, Ltd., particle diameter 10 to 20 nm,
(A silica content of 30% by weight) was added and stirred at room temperature for about 1 hour to obtain a coating liquid.

The coating solution was applied on sample H in the same manner as described in Example 1, and heat-treated at 500 ° C. for 1 hour to obtain sample I (glass substrate / alkali-blocking silica film / titania fine particles and silica fine particles). A dispersed iron-added silica film / silica overcoat thin film) was obtained. As a result of measurement with an atomic force microscope, the surface of Sample I was an uneven surface having an arithmetic average roughness (Ra) of 6 nm and an average interval (Sm) of unevenness of 45 nm. The average thickness of this silica overcoat layer determined by ESCA was about 2 nm.

Table 4 shows the results of various antifogging performance evaluations of Sample I.
Shown in It is clear that the anti-fog performance is excellent. The abrasion resistance was also good.

[Comparative Example 3] [Formation of photocatalytic film (titania fine particle-dispersed silica film)] Alcohol (trade name: AP-7, manufactured by Nippon Kasei Co., Ltd.)
195.32 g of titania colloid (trade name: ST-K
01, manufactured by Ishihara Sangyo Co., Ltd., titania content: 8% by weight,
4.00 g of silica content (2% by weight) and 0.68 g of tetrachlorosilane were added, and the mixture was stirred at room temperature for about 1 hour to obtain a coating liquid.

Except that the above coating solution for titania fine particle-dispersed silica film was used instead of the silica fine particle-dispersed iron-added titania film coating solution used in Example 1 on the glass substrate provided with an alkali barrier film prepared in Example 1. Is applied once by the same method as described in Example 1,
For 1 hour to obtain Sample J (glass substrate / alkali blocking silica film / titania fine particle dispersed silica film). This photocatalyst film contained 50% of titanium oxide with respect to the unit weight of the film. As a result of analysis by X-ray diffraction, it was confirmed that titanium oxide in the photocatalytic film of Sample J was an anatase crystal. The thickness of the photocatalyst film of Sample J was determined to be about 90 nm by an electron microscope, and as a result of measurement by an atomic force microscope, the surface was found to have an arithmetic average roughness (Ra) of 3 nm and an average interval of unevenness (Sm). Had an uneven surface of 300 nm.

Table 4 shows the results of various antifogging performance evaluations of Sample J.
Shown in It is clear that the antifogging performance is not so good as compared with the examples. The abrasion resistance was good.

Example 6 The procedure of Example 1 was repeated except that the iron-added solution described in [Formation of Photocatalytic Film] in Example 1 was diluted 50 times by weight with ethanol, and this was newly used as the iron-added solution. Sample K (glass substrate / alkali blocking silica film / iron-added silica fine particle-dispersed titania-silica film / silica overcoat film) was obtained in exactly the same manner as described in 1. The photocatalytic film of Sample K contained 50% of titanium oxide and 0.005% of iron with respect to the unit weight of the film. As a result of analysis by X-ray diffraction, it was confirmed that the titanium oxide in the photocatalyst layer of Sample K was an anatase crystal. Sample K measured by electron microscope
The thickness of the photocatalyst layer was about 200 nm. In addition, as a result of measurement with an atomic force microscope, the surface of the sample K was an uneven surface having an arithmetic average roughness (Ra) of 10 nm and an average interval (Sm) of unevenness of 50 nm. The average thickness of this silica overcoat film was found to be about 5 nm by ESCA.

Table 4 shows the results of evaluating various antifogging performances of Sample K.
Shown in It is clear that the anti-fog performance is excellent. The abrasion resistance was also good.

Comparative Example 4 The procedure of Example 3 was repeated except that the iron-added liquid described in [Formation of Photocatalyst Film] was replaced by a coating liquid for a titania film dispersed with fine silica particles in which the amount of iron acetylacetone was added to zero. Sample L (glass substrate / alkali blocking silica film / silica fine particle-dispersed titania-silica film / silica overcoat film) was obtained in exactly the same manner as in Example 3 (sample E). As a result of measurement with an atomic force microscope, the surface of the sample L had an arithmetic average roughness (Ra) of 12 nm and an average interval of unevenness (Sm).
Had an irregular surface of 40 nm. Also, ESC
When the average thickness of this silica overcoat layer was determined by A, it was about 5 nm.

Table 4 shows the results of various antifogging performance evaluations of Sample L.
Shown in It is clear that the antifogging performance is not so good as compared with the examples. The abrasion resistance was good.

[Comparative Example 5] [Formation of photocatalyst layer (iron-added titania film with fine silica particles dispersed therein)]
A solution diluted to 00 times by weight was newly used as an iron-added solution, and instead of 0.80 g of the iron-added solution described in Example 1, 0.253 g of this new iron-added solution was used. A coating solution was prepared under exactly the same conditions as in the method.

Using this coating solution, a photocatalyst layer was formed on the glass substrate with an alkali-blocking silica film described in Example 1 by the method described in Example 1.

[Formation of Overcoat Layer (Silica Film)]
A silica overcoat layer was further formed on the photocatalyst layer in exactly the same manner as described in Example 1,
For 2 minutes to obtain Sample M (glass substrate / alkali-blocking silica film / titania-silica film with fine particles of silica added small amount of iron / silica overcoat layer). The photocatalyst layer of sample M (iron fine particle-added silica fine particle-dispersed titania-silica film) contained 50% of titanium oxide and 0.0008% of iron with respect to the unit weight of the film. As a result of analysis by X-ray diffraction, it was confirmed that the titanium oxide in the photocatalyst layer of Sample M was an anatase crystal. The thickness of the photocatalyst layer of Sample M measured by an electron microscope was about 200 nm. As a result of measurement with an atomic force microscope, the surface of the sample M was an uneven surface having an arithmetic average roughness (Ra) of 10 nm and an average interval (Sm) of unevenness of 50 nm. The average thickness of this silica overcoat layer determined by ESCA was about 5 nm.

Table 4 shows the results of various antifogging performance evaluations of Sample M.
Shown in It is clear that the antifogging performance is inferior to that of Example 1. The abrasion resistance was good.

[Comparative Example 6] [Formation of photocatalytic layer (silica fine particle-dispersed iron-added titania film)] Instead of adding 0.80 g of the iron-added solution described in Example 1, 43.12 g of the iron-added solution was added, and solvent 173 was added. .49g
Instead of using 131.17 g of the same solvent, a coating solution was prepared under exactly the same conditions as in the method described in Example 1.

Using this coating solution, a photocatalyst layer was formed on the glass substrate with an alkali-blocking silica film described in Example 1 by the method described in Example 1.

[Formation of Overcoat Layer (Silica Film)]
A silica overcoat layer was further formed on the photocatalyst layer in exactly the same manner as described in Example 1,
For 2 minutes to obtain Sample N (glass substrate / alkali blocking silica film / iron-added silica fine particle-dispersed titania-silica film / silica overcoat layer).
The photocatalyst layer (iron-added silica fine particle-dispersed titania-silica film) of Sample N contained 46% titanium oxide and 12% iron with respect to the unit weight of the film. As a result of analysis by X-ray diffraction, it was confirmed that the titanium oxide in the photocatalyst layer of Sample N was an anatase crystal. The thickness of the photocatalyst layer of Sample N measured by an electron microscope was about 210 nm. As a result of measurement with an atomic force microscope, the surface of the sample N was found to have an arithmetic average roughness (R
a) is 60 nm, and the average interval (Sm) of the unevenness is 1
The surface had an uneven surface of 80 nm. Also, ESCA
As a result, the average thickness of this silica overcoat layer was about 5 nm.

Table 4 shows the results of various antifogging performance evaluations of Sample N.
Shown in The antifogging recovery performance is slightly inferior to that of Example 1, and the abrasion resistance of the film is remarkably inferior. The decrease in wear resistance of this film is considered to be due to the addition of a large amount of iron.

[0110]

[Table 4] ────────────────────────────────San Antifogging Water droplet contact angle Antifogging evaluation Wear resistance P Maintain time factor (day) Maintainability Recoverability 例 Example 1B7. 0 0.28 O O O 2C 6.3 0.09 O O O 3E 6.0 0.20 O O O 4G 31.9 0.08 O O O 5 I 28.0 0.12 O O ○ 6 K 7.1 0.25 ○ ○ ○ −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparative Example 1 A ′ 2 0.0 0.84 × × ○ 2 F '2.8 0.40 × △ ○ 3 J 3.2 0.90 △ × ○ 4 L 5.9 0.31 △ △ ○ 5 M 5.9 0.33 △ △ ○ 6 N 8.8 0.31 ○ △ × ─────────── ────────────────────

[0111]

As described above, it is clear that the glass article of the present invention has excellent antifogging performance and its maintainability, and has good mechanical durability. It can be suitably used for applications such as industrial, architectural and optical applications.

Continuing on the front page (72) Inventor Hiroyuki Inomata 3-5-11, Doshumachi, Chuo-ku, Osaka-shi Japan Sheet Glass Co., Ltd. (72) Inventor Yasuo Kai 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co. ( 72) Inventor Ryuzo Uemura 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture, Nissan Motor Co., Ltd. AC20 AD09 4G059 AA01 AC01 AC21 EA05 EB05 GA02 GA04 GA14 4G069 AA03 BA01A BA01B BA02A BA02B BA04A BA04B BA05A BA05B BA48A BC01A BC26A BC26B BC43A BC43B 4H020 AA01 AB02

Claims (16)

[Claims] 1. An alkali barrier film on a surface of a glass substrate,
In an antifogging glass article in which a photocatalytic film and an overcoat film are laminated in that order, and the surface of the antifogging glass has irregularities, the photocatalytic film contains at least 30% by weight of titanium oxide and an iron compound in an amount of 0% in terms of Fe. 0.001 to 10% by weight, respectively. 2. The antifogging glass article according to claim 1, wherein the iron compound is iron oxide. 3. The antifogging glass article according to claim 1, wherein the photocatalytic film is composed of fine particles and a matrix, and the titanium oxide is at least one of the fine particles and the matrix. 4. The fine particles are titanium oxide fine particles having a particle diameter of 4 to 300 nm, and the matrix of the photocatalytic film is composed of silicon oxide, aluminum oxide, an alkali metal,
The anti-fogging glass article according to claim 3, which is at least one oxide selected from the group consisting of zirconium oxide, antimony oxide, amorphous titanium oxide, hydrous titanium oxide, cerium oxide and titanium oxide crystals. 5. A matrix of the photocatalytic film is made of titanium oxide, and the fine particles are made of at least one oxide selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, cerium oxide and titanium oxide. 4. Fine particles having a particle size of
The anti-fogging glass article according to the above. 6. The unevenness has an arithmetic average roughness (Ra).
Is 0.5 to 100 nm, and the average distance between irregularities (S
m) is from 4 to 300 nm.
Item 13. The anti-fogging glass article according to Item. 7. The antifogging glass article according to claim 1, wherein the photocatalytic film has a thickness of 100 to 300 nm. 8. The overcoat film having a thickness of 4 to 300 n
2. A film containing hydrophilic metal oxide fine particles having a particle size of m and comprising a hydrophilic metal oxide as a matrix.
58. The anti-fogging glass article according to any one of -57. 9. The antifogging glass article according to claim 8, wherein the metal oxide fine particles are contained in the overcoat film in an amount of 5% by weight or more and 80% by weight or less. 10. The metal oxide fine particles are silicon oxide,
The fine particles of at least one oxide selected from the group consisting of aluminum oxide, zirconium oxide, cerium oxide and titanium oxide, wherein the metal oxide matrix of the overcoat film is silicon oxide, aluminum oxide,
The anti-fogging glass article according to claim 8 or 9, which is at least one metal oxide selected from the group consisting of zirconium oxide, cerium oxide, and a composite of titanium oxide and another metal oxide. 11. The anti-fogging glass article according to claim 8, wherein the metal oxide fine particles include at least chain silica fine particles. 12. The method according to claim 11, wherein the chain silica fine particles are 10 to 20.
3. The method of claim 1, wherein the diameter is between about 40 nm and about 300 nm.
2. The antifogging glass article according to 1. 13. The antifogging glass according to claim 8, wherein the metal oxide matrix of the overcoat film is silicon oxide, and the overcoat film contains silicon oxide in an amount of 50% by weight or more. Goods. 14. The method according to claim 14, wherein the overcoat film has a thickness of 0.1-5.
The antifogging glass article according to any one of claims 1 to 13, having a thickness of 0 nm. 15. The alkali barrier film contains at least 50% by weight of silicon oxide and additionally contains at least one metal oxide selected from the group consisting of titanium oxide, zirconium oxide and aluminum oxide in a total amount of 0%. ~ 5
The antifogging glass article according to any one of claims 1 to 14, which contains 0% by weight. 16. The method according to claim 16, wherein the alkali barrier film has a thickness of 5 to 100 n.
The antifogging glass article according to any one of claims 1 to 15, having a thickness of m.