Antifogging and antifouling glass article

The present invention relates to antifogging and antifouling glass articles, particularly antifogging and antifouling glass plates for automobiles and buildings, and eyeglasses, mirrors, lenses, showcases and other antifogging and antifouling glass articles.

There has been a strong need for anti-fog and anti-fouling glass plates for a long time, mainly in the fields of automobiles and construction. Especially in automobiles, it is becoming an important issue to impart antifogging and antifouling properties to windowpanes from the viewpoint of safe driving.

Conventionally, various antifogging and antifouling coatings for glass articles have been studied. For example, coating of an organic and / or inorganic thin film containing a surfactant (hereinafter, "Method 1", for example, Patent Document 1), coating of a hydrophilic polymer (hereinafter, "Method 2", for example, Patent Document 2), hydrophilic organic. Coating of an organic-inorganic composite film containing a functional group (hereinafter, Method 3, for example, Patent Document 3) and the like.

Recently, an antifogging and antifouling glass having a glass surface coated with a titanium oxide thin film acting as a photocatalyst has been proposed (hereinafter, "Method 4", for example, Non-Patent Document 1). This utilizes the fact that titanium oxide on the surface of the glass absorbs ultraviolet light and the energy of the titanium oxide efficiently oxidatively decomposes the organic substances adsorbed on the glass surface, resulting in a clean surface having remarkable hydrophilicity. Is. In addition to being made entirely of inorganic materials and having excellent mechanical strength, even if dirt adheres to it, once it is exposed to light, the surface is cleaned again and the hydrophilic surface is restored. If the surface maintains hydrophilicity, it is difficult for lipophilic black stains, which are urban stains, to be attached, and the attached stains are easily removed by rainfall (for example, Non-Patent Document 2 and Non-Patent Document 3), so-called self-cleaning. It has properties and can be used as an antifouling material.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 7-17202</text></patcit><patcit num="2"><text>Japanese Patent No. 1344292</text></patcit><patcit num="3"><text>Japanese Patent Application Laid-Open No. 6-220428</text></patcit><nplcit num="1"><text>"Ceramics" magazine, Vol. 31, pp.837-840 (1996)</text></nplcit><nplcit num="2"><text>Toshiki Komatsuzawa, Toshikazu Nakaya, "New Antifouling Paint", "Painting Technology" Magazine, January 1995, pp.94-99 (1995)</text></nplcit><nplcit num="3"><text>Shoichi Tanaka, "Pollution Deterioration and Stain Resistant Paint Technology (Industrial Paint)", "Painting Technology" magazine, October 1996 special issue, pp.95-102 (1995)</text></nplcit>

<p> Although the method 1 is excellent in initial performance, it has a drawback that it has a short life because the surfactant is gradually consumed.</p><p> Although the method 2 is an effective means depending on the application, it cannot be applied to glass that requires relatively large mechanical strength such as automobiles and buildings.</p><p> The method 3 has been devised in order to achieve both antifogging performance and mechanical strength, but all of them have limitations in terms of performance. Further, there is also a problem that the antifogging performance is remarkably lowered once the dirt is attached.</p><p> Although the above method 4 has characteristics that cannot be realized by other methods in principle, the intensity of ultraviolet light inside automobiles and buildings is very weak, so that it is an antifogging and antifouling glass article that can be put into practical use. Has not been obtained so far.</p><p> An object of the present invention is to provide an antifogging and antifouling glass article having excellent long-term antifogging and antifouling performance that can be used for window glass and eyeglasses of automobiles and buildings.</p>

<p> In the present invention, an alkali blocking film, a photocatalytic film, and a silicon oxide layer or at least one functional group selected from the group consisting of a polyalkylene oxide group, an alkyl group, an alkenyl group and an aryl group are intramolecularly formed on the surface of a glass substrate. It is an antifogging and antifouling glass article formed by laminating an organic substance adhesion prevention layer composed of a layer of an organosilane or a hydrolyzate thereof in that order, wherein the photocatalyst film contains 10% by weight or more of titanium oxide and contains a fluorine atom. There are anti-fog and anti-fouling glass articles containing. Further, the present invention is the antifogging and antifouling glass article in which the photocatalyst film is made of titanium oxide and contains a fluorine atom. Further, the present invention is the antifogging and antifouling glass article in which the photocatalyst film contains 0.002 to 1% by weight of fluorine atoms. Further, in the present invention, at least one functional group selected from the group consisting of an alkali blocking film, a photocatalyst film, and a silicon oxide layer or a polyalkylene oxide group, an alkyl group, an alkenyl group and an aryl group is formed on the surface of a glass substrate. An antifogging and antifouling glass article formed by laminating an organic substance adhesion prevention layer composed of a layer of an organosilane or a hydrolyzate thereof contained therein in that order, wherein the photocatalyst film contains 10% by weight or more of titanium oxide and the alkali. It is an antifogging and antifouling glass article in which the blocking film contains a fluorine atom. Further, the present invention is the antifogging and antifouling glass article in which the photocatalyst film is made of titanium oxide. Further, the present invention is the antifogging and antifouling glass article in which the alkali blocking film contains 0.002 to 10% by weight of fluorine atoms. Further, the present invention is the antifogging and antifouling glass article in which the photocatalyst film further contains fluorine atoms. Further, the present invention is the anti-fog and anti-fouling glass article in which the organic substance adhesion prevention layer has an average number of molecular layers in the thickness direction of 0.5 to 5.</p><p> Here, the Ra value and the Sm value are defined by the method described in JIS B0601 (1994), and are defined by an atomic force microscope (for example, SPI3700 manufactured by Seiko Electronics Co., Ltd.) and an electron microscope (for example, H-600 manufactured by Hitachi, Ltd.). It can be calculated from the cross-sectional curve observed and measured using.</p><p> In order to obtain an excellent anti-fog and anti-fouling function using a photocatalyst, it is necessary to satisfy three conditions at the same time. One is to efficiently oxidatively decompose organic substances adsorbed on the surface of the photocatalytic film, which cause fogging and stains (high photocatalytic activity). The second is that organic substances are hard to be adsorbed on the surface (adsorption prevention property). The third, which is particularly necessary for anti-fog properties, is to reduce the apparent contact angle when water droplets adhere (lower contact angle). Only when the above three conditions are satisfied can good anti-fog and anti-fouling performance for a long period of time be exhibited.</p><p> In the present invention, the photocatalyst is TiO.₂, ZnO, ZnS, WO₃, Fe₂O₃, GaAs, CdSe, GaAsP, CdS, SrTiO₃, GaP, In₂O₃, MoO₃However, due to its high photocatalytic activity and chemical stability, the most widely used photocatalyst at present is TiO.₂Therefore, it can be particularly preferably used in the present invention. Titanium oxide will be typically described below.</p><p> Even if the surface of the glass substrate is directly coated with a photocatalytic film such as a titanium oxide film, high photocatalytic activity cannot be obtained. This is because alkali metal ions such as Na ions diffused out from the glass substrate containing the alkali metal during the heat treatment reduce the crystallinity of the titanium oxide film. In order to prevent the decrease in crystallinity of the titanium oxide film, in the present invention, a silicon oxide film or other alkali blocking film is provided on the glass substrate, and a photocatalyst film made of titanium oxide or a photocatalyst film containing titanium oxide is provided on the silicon oxide film. To coat. When a film containing titanium oxide is used as the photocatalyst film, the content of titanium oxide is preferably 10% by weight or more. If the amount of titanium oxide is less than 10% by weight, the photocatalytic activity of the surface becomes too low to be practical.</p><p> [Alkali blocking film] As the alkali blocking film, one having a single component or multi-component composition selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, and cerium oxide is preferably used. Among these, a single component of silicon oxide (silica) or a multi-component type in which the 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 form a film without significantly impairing the optical characteristics of the glass plate. The two-component metal oxide of silicon oxide and zirconium oxide is alkaline. It is more preferable because the blocking performance is very high, and the content of zirconium oxide is particularly preferably 1% by weight or more and 30% by weight or less. If the content is lower than 1% by weight, the effect of improving the alkali blocking performance is not so different from that of silicon oxide alone, and if it is higher than 30% by weight, not only the effect of improving the alkali blocking performance is no longer improved, but also the reflectance is improved by increasing the refractive index. It is not preferable because the tendency to occur becomes strong and it becomes difficult to control the optical characteristics of the glass plate.</p><p> The thickness of the alkali blocking film is preferably 10 nm or more and 300 nm or less. If the thickness is thinner than 10 nm, the alkali blocking effect is not sufficient, and if it is thicker than 300 nm, the interference color due to the film becomes noticeable and it becomes difficult to control the optical characteristics of the glass plate, which is not preferable.</p><p> The alkali blocking film can be formed by a known method. For example, the sol-gel method (for example, Yuji Yamamoto, Hirokazu Kamiya, Saio Sakuhana, Journal of Ceramics Association, 90, 328 ~ 333 (1982)), liquid phase deposition method (for example, special fair 1-59210, special fair 4-13301). , Vacuum film formation method (vacuum deposition, sputtering), baking method / spray coating (for example, Japanese Patent Application Laid-Open No. 53-124523, Japanese Patent Application Laid-Open No. 56-96749), CVD method (for example, Japanese Patent Application Laid-Open No. 55-90441, JP-A 1-201046) , Japanese Patent Application Laid-Open No. 5-208849) and the like can be exemplified.</p><p> For the alkali blocking film by the sol-gel method, a coating solution containing a hydrolyzable / polycondensable organic metal compound or a chlorosilyl group-containing compound or a hydrolyzate thereof is applied onto a glass substrate, dried, and heat-treated as necessary. It is formed by</p><p> As the solvent of the fine particles, water, methanol, ethanol, propanol or the like is preferable, and water is more preferable.</p><p> Examples of the hydrolyzable / shrinkable organometallic compound contained in the coating liquid for forming an alkali blocking film include metal alkoxides such as methoxides such as silicon, aluminum, zirconium and titanium, ethoxides, propoxides and butoxides. It is preferably used as a simple substance or a mixture, and high-molecular-weight alkyl silicates such as "Ethyl silicate 40" manufactured by Corcote Co., Ltd. and "MS56" manufactured by Mitsubishi Chemical Co., Ltd. can also be used. As the organometallic compound hydrolyzate, commercially available alkoxysilane hydrolyzate, for example, "HAS-10" manufactured by Corcote Co., Ltd., "Ceramica G-91", "G-92-6" manufactured by Nichiban Kenkyusho Co., Ltd., "Atron NSI-500" manufactured by Nippon Soda Co., Ltd. can be used.</p><p> The chlorosilyl group-containing compound contained in the coating liquid for forming an alkali blocking film is a chlorosilyl group (-SiCl)._nX_3-n, Where n is 1,2, or 3, and X is hydrogen, or a compound having at least one alkyl group, alkoxy group, or acyloxy group each having 1 to 10 carbon atoms in the molecule. Among them, a compound having at least two chlorines is preferable, and silane Si is preferable._nH_{2n + 2}Chlorosilane in which at least two hydrogens in (where n is an integer from 1 to 5) are substituted with chlorine and other hydrogens are optionally substituted with the alkyl group, alkoxy group, or asyloxy group and their contractions. Polymers are preferred, for example tetrachlorosilane (silicon tetrachloride, SiCl).₄), Trichlorosilane (SiHCl)₃), Trichloromonomethylsilane (SiCH)₃Cl₃), Dichlorosilane (SiH)₂Cl₂), And Cl- (SiCl)₂O)_n-SiCl₃(N is an integer from 1 to 10) and the like. Hydrolyzates of the chlorosilyl group-containing compound can also be used, and among these, one or a plurality of them can be used, but the most preferable chlorosilyl group-containing compound is tetrachlorosilane. The chlorosilyl group is very reactive and forms a dense film by self-condensation or condensation reaction with the surface of the substrate.</p><p> The solvent of the solution containing the organic metal compound or the chlorosilyl group-containing compound or a hydrolyzate thereof may be basically anything as long as it dissolves the organic metal compound or the chlorosilyl group-containing compound or their hydrolyzate. Alcohols such as methanol, ethanol, propanol and butanol are most preferable, and the total of the organic metal compound, the chlorosilyl group-containing compound and their hydrolyzates is contained at a concentration of 1 to 30% by weight.</p><p> Water is required for hydrolysis of the organometallic compound. This may be either acidic or neutral, but in order to promote hydrolysis, it is preferable to use water acidified with hydrochloric acid, nitric acid, sulfuric acid, acetic acid, citric acid, sulfonic acid or the like having a catalytic action. .. The amount of the acid added is not particularly limited, but a molar ratio of 0.001 to 5 with respect to the organometallic compound is preferable. If the amount of the added acid is less than 0.001 in terms of molar ratio, the promotion of hydrolysis of the organometallic compound is not sufficient, and if it is more than 5 in molar ratio, the effect of promoting hydrolysis is no longer improved, which is not preferable.</p><p> The amount of water added for hydrolysis of the organometallic compound is preferably 0.1 to 100 in terms of molar ratio with respect to the organometallic compound. If the amount of water added is less than 0.1 in terms of molar ratio, the promotion of hydrolysis of the organometallic compound is not sufficient, and if it is more than 100 in molar ratio, the stability of the liquid tends to decrease, which is not preferable.</p><p> 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 the water contained in the solvent and the water in the atmosphere. In addition, hydrochloric acid is liberated in the liquid along with this hydrolysis, and the hydrolysis further proceeds. However, there is no problem even if water or acid is added additionally.</p><p> The organometallic compound, the chlorosilyl group-containing compound, or a hydrolyzate thereof is mixed with a solvent, and water, an acid catalyst, and a dispersion aid are added as necessary to prepare a coating liquid. At this time, the organometallic compound and the chlorosilyl group-containing compound may be used alone or in combination.</p><p> The organic metal compound or the 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 to form a coating solution for forming an alkali blocking film. To get. When a chlorosilyl group-containing compound is used, it is not necessary to add a catalyst and water in particular. Further, in order to omit the step of hydrolyzing the organometallic compound, the commercially available organometallic compound hydrolyzate solution may be used. The obtained coating liquid may then be diluted with an appropriate solvent depending on the coating method.</p><p> Next, for the alkali blocking film by the liquid phase precipitation method, for example, the silicate glass substrate is immersed in a silica supersaturated aqueous solution of 1 to 4 mol / L concentration of hydrofluoric acid at 25 to 50 ° C for 1 to 4 hours. As a result, silicon oxide is deposited on the surface of the base material from the aqueous solution, and an alkali-blocking silicon oxide film is formed. The silica supersaturated hydrofluoric acid aqueous solution is dissolved in a silicate hydrofluoric acid aqueous solution having a concentration of 1 to 4 mol / L, and boric acid is further added to 1 × 10.^-4~100×10^-4It is obtained by adding to a concentration of mol / L.</p><p> [Photocatalytic film] The photocatalytic activity of the photocatalytic film coated on the alkali blocking film strongly depends on the film thickness. If the film thickness is too thin, light cannot be sufficiently absorbed, and if the film thickness is too thick, the photocarriers generated in the film cannot be diffused to the outer surface of the film, so that both the catalytic activity is lowered. Although the optimum film thickness varies depending on the usage conditions, good photocatalytic activity can be exhibited in the range of 10 nm to 500 nm, more preferably in the range of 50 to 200 nm.</p><p> The photocatalyst film made of titanium oxide or the photocatalyst film containing titanium oxide in the present invention is produced by using a usual thin film production method, and the sol-gel method is particularly preferably applied. The sol is obtained by simultaneously hydrolyzing titanium alkoxide or titanium alkoxide and another metal alkoxide. Further, 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), and it is preferably used. Examples of commercially available liquids are "ST-K03" (manufactured by Ishihara Sangyo Co., Ltd., titanium oxide content 5% by weight, inorganic binder content 5% by weight) and "CA-62" (manufactured by Taki Chemical Co., Ltd., Titanium oxide content 6% by weight, binder amount 1.5% by weight) and the like.</p><p> After forming a titanium oxide-based thin film on these alkali blocking films, heat treatment is preferably performed at 450 to 650 ° C for 10 minutes to 2 hours in order to densify and improve titanium oxide crystallinity.</p><p> [Fluorine Doping to Photocatalytic Membrane] Further, by doping a small amount of fluorine atoms in the photocatalytic membrane, it is possible to further increase the photocatalytic activity. As the dopant, trifluoroacetic acid or the like can be used. These dopants such as trifluoroacetic acid are decomposed by the subsequent heat treatment and doped into the titanium oxide crystal lattice as atomic-state fluorine. Since the size of the fluorine atom is almost the same as the size of the oxygen atom, it is considered that the doped fluorine atom exists mainly in the form of being replaced with the oxygen atom of titanium oxide.</p><p> When a titanium oxide-based photocatalyst film is formed by the sol-gel method, it is fired by adding a thermally decomposable fluorine compound such as trifluoroacetic acid (TFA) to the titanium alkoxide solution or titanium oxide fine particle dispersion. Fluorine atoms are doped in 0.002 to 1% by weight in the film after the heat treatment such as, and the photocatalytic activity can be further increased.</p><p> Further, when a titanium oxide photocatalyst film is formed by a vacuum vapor deposition method or a chemical vapor deposition (CVD) method, the same fluorine atom doping can be performed by adding a fluorine compound to the raw material.</p><p> If the amount of fluorine atom doping in the film is less than 0.002% by weight, the effect of increasing the photocatalytic activity is not so remarkable, and if it is more than 1% by weight, the photocatalytic activity is no longer increased, which is not preferable.</p><p> On the other hand, by doping the alkali blocking film with fluorine atoms, the fluorine atoms are diffused in the titanium oxide-based film by the heat treatment, and the same doping effect can be obtained. The amount of fluorine atom doping in the alkali blocking film is preferably 0.002% by weight or more and 10% by weight or less. If the amount of fluorine atom doping in the alkali blocking film is less than 0.002% by weight, the effect of increasing the photocatalytic activity of the photocatalytic layer is not so remarkable, and if it is more than 10% by weight, the photocatalytic activity of the photocatalytic layer is no longer increased, which is preferable. Absent.</p><p> Fluorine atom doping into the alkali blocking film is usually done by adding a fluorine compound to the raw material when the alkali blocking film is prepared by the sol-gel method, vacuum deposition method, baking method, spray coating method, CVD method, etc. Used. When an alkali blocking film of silicon oxide is formed by the liquid phase precipitation method, 0.1 to 10% of fluorine is contained in the raw material solution (silica supersaturated solution of hydrofluoric acid), so this raw material solution. It is not necessary to add a special fluorine compound to the product and it can be used as it is.</p><p> [Organic matter adhesion prevention layer] It is preferable to form the following organic matter adhesion prevention layer on the photocatalyst film. A photocatalytic film such as a highly active titanium oxide film has a small contact angle of 5 degrees or less immediately after irradiation with ultraviolet rays, and has considerably good initial antifogging performance. However, since organic substances are easily adsorbed on the surface thereof, the antifogging performance tends to deteriorate over time due to an increase in the amount of adsorbed organic substances. In the present invention, it is preferable to form a SiOx single molecule equivalent layer (x is 1 to 2) on the surface of the photocatalytic film, whereby the adsorption of organic substances is effectively suppressed while maintaining high photocatalytic activity. And the deterioration of the antifogging property is prevented. The formation of a single molecule equivalent layer of SiOx, which is an organic substance adhesion prevention layer, is performed by chemically adsorbing the vapor of a silicon compound such as 1,3,5,7-tetramethylcyclotetrasiloxane on the surface of a photocatalyst or an organic silicon compound, for example. It can be preferably carried out by applying a liquid containing tetraalkoxysilane to the surface of the photocatalyst film and then irradiating or heating it with ultraviolet light in the presence of oxygen to decompose it. In addition, vacuum deposition A single molecule equivalent layer of SiOx may be directly formed by a method such as a method, an LB method, or a liquid phase precipitation method. Further, instead of the SiOx single molecule equivalent layer, an organic metal compound containing at least one functional group selected from the group consisting of a polyalkylene oxide group, an alkyl group, an alkenyl group and an aryl group in the molecule or a hydrolyzate thereof is used as a photocatalyst film. By covering the surface, the antifouling performance is remarkably improved. These organometallic compounds are gradually decomposed by external factors such as irradiation with ultraviolet light and temperature rise, and finally form a metal oxide single molecule equivalent layer such as SiOx, and the antifouling performance is maintained. Here, the monomolecular equivalent layer is substantially a monomolecular layer, and refers to a layer of molecules in which 0.5 to 5 molecules are arranged on average in the thickness direction.</p><p> As the polyalkylene oxide group contained in the molecule of the organometallic compound, a polyethylene oxide group, a polypropylene oxide group and the like are mainly used. Examples of the alkyl group include a chain alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group and a decyl group, and a cyclopentyl group. , Cyclic alkyl groups having 3 to 10 carbon atoms such as cyclohexyl groups are mainly used. As the alkenyl group, a group having 1 to 10 carbon atoms such as a vinyl group, an allyl group, a butenyl group, a propenyl group, a hexenyl group, an octenyl group and a cyclohexenyl group is mainly used. As the aryl group, a phenyl group, a tolyl group, a xsilyl group and the like are mainly used. Organic metal compounds containing these functional groups, such as polyethylene oxide groups, include [alkoxy (polykoxy) alkyl] trialkoxysilanes, organosilanes such as [alkoxy (polyethyleneoxy) alkyl] trichlorosilanes, and [ Alkoxy (polykoxy) alkyl] Organic titanium compounds such as trialkoxy titanium can be mentioned.</p><p> Since these functional groups are non-polar or low-polar, they are preferable because they have low stain adhesion and suppress the increase in contact angle with respect to water droplets, that is, they have good antifogging durability and hydrophilicity retention. In particular, the antifogging and antifouling article prepared by using an organosilane containing a polyalkylene oxide group is particularly preferable because it has good antifogging properties and is particularly excellent in antifogging durability and hydrophilicity retention (that is, antifouling property). .. As described above, the higher the hydrophilicity retention property, the better the antifouling property.</p><p> Further, since the functional group is non-reactive or low-reactivity, it does not form a chemical bond with a stain component, stains are not fixed to the surface, and stains adhering to the surface can be easily wiped off. Since it can be removed, even if the antifogging property is lost due to dirt, the antifogging property can be easily restored.</p><p> The organosilane containing a polyalkylene oxide group is preferably an alkoxysilane or chlorosilane having an alkoxyl group or a chloro group in the molecule. The alkoxyl group and the chloro group are easily hydrolyzed so that the organosilane can be strongly chemically bonded to the surface of the photocatalyst film, so that the product has higher antifogging durability. Among the organosilanes, an alkoxysilane containing a polyethylene oxide group, particularly [alkoxy (polyethyleneoxy) alkyl] trialkoxysilane, for example, [methoxy (polyethyleneoxy) propyl] trimethoxysilane is most preferable.</p><p> The method for binding or adhering the organosilane or its hydrolyzate to the surface of the photocatalyst membrane may be any method as long as the organosilane or its hydrolyzate comes into contact with the surface of the photocatalyst membrane. For example, a method of applying a liquid containing the organosilane or a hydrolyzate thereof to the surface of a photocatalyst film (coating method), a method of immersing a photocatalyst film-forming article in a liquid containing the organosilane or a hydrolyzate thereof (liquid phase chemistry). Adsorption method), a method in which a photocatalyst film-forming article is placed in the vapor of the organosilane or its hydrolyzate and adsorbed (gas phase chemical adsorption method) and the like can be mentioned.</p><p> Of the above methods, the coating method is particularly preferable because it is the simplest and has the lowest cost. The coating method may be a known technique and is not particularly limited, but is a method using a device such as a spin coater, a roll coater, a spray coater, a curtain coater, a dipping pulling method (dip coating method), or a sink coating method. (Flow coating method), cloth or paper soaked in coating liquid in contact with the surface of the photocatalyst film and rubbing with appropriate force (rubbing method), screen printing, gravure printing, curved surface printing, etc. Various printing methods are used.</p><p> The solvent for dissolving the organosilane is not particularly limited, but water, alcohols, and ketones are preferably used alone or in combination from the viewpoint of safety, cost, and workability. Examples of alcohols include methanol, ethanol, propanol and butanol, and examples of ketones include acetone, methyl ethyl ketone and diethyl ketone.</p><p> The organosilane is hydrolyzed and used as necessary. Water and an acid catalyst are added to the organosilane solution, and the solution is hydrolyzed at a constant temperature for a certain period of time, diluted if necessary, and used for coating.</p><p> The conditions for hydrolysis are not particularly limited, but it is preferable to carry out the hydrolysis at a temperature of 20 to 60 ° C. for 3 minutes to 50 hours. If the temperature is lower than 20 ° C or the time is shorter than 3 minutes, the promotion of hydrolysis is not sufficient, and if the temperature is higher than 60 ° C or the time is longer than 50 hours, the effect of promoting hydrolysis is no longer sufficient. Is not preferable because the coating solution life is shortened.</p><p> As the acid catalyst, in addition to mineral acids such as hydrochloric acid, sulfuric acid and nitric acid, organic acids such as acetic acid, formic acid, citric acid and p-toluenesulfonic acid are used. The amount of acid added is not particularly limited, but a molar ratio of 0.0001 to 5 with respect to organosilane is preferable. If the amount of added acid is less than 0.0001 in terms of molar ratio, the promotion of hydrolysis of organosilane is not sufficient, and if it is more than 5 in molar ratio, the effect of promoting hydrolysis is no longer improved and the acid becomes excessive. Not preferable.</p><p> The amount of water added for hydrolysis is not particularly limited, but the molar ratio to organosilane is preferably 0.1 or more. If the amount of water added is less than 0.1 in terms of molar ratio, the promotion of hydrolysis of organosilane is not sufficient, which is not preferable.</p><p> On the other hand, in the case of polyalkylene oxide group-containing organosilane having a high hydrolysis rate, such as [alkoxy (polyethyleneoxy) alkyl] trichlorosilane, sufficient hydrolysis proceeds only with the water adsorbed on the surface of the photocatalyst membrane, and the dehydration condensation reaction proceeds. It may be possible to fix it on the surface. In this case, it is better to prepare the coating liquid using a non-aqueous solvent in which the dissolved water is sufficiently reduced, so that the obtained anti-fog article has weather resistance, anti-fog antifouling property, anti-fog durability and hydrophilicity retention. It is preferable because an excellent product can be obtained. Examples of the non-aqueous solvent include n-hexane, cyclohexane, xylene, and toluene.</p><p> The concentration of the organosilane solution used for coating is not particularly limited, but 0.001 to 5% by weight is preferably used. If the concentration is lower than 0.001% by weight, it becomes difficult to recognize sufficient improvement in antifogging durability and hydrophilicity retention in the obtained antifogging and antifouling article, and even if the concentration is higher than 5% by weight, the antifogging performance and antifouling performance are improved. It is not economical and not preferable because it does not improve.</p><p> The photocatalytic membrane after coating with the organosilane solution is preferably dried or heat-treated at a temperature of 20 to 180 ° C. for 3 minutes to 3 hours. By this treatment, the bond of organosilane to the surface of the photocatalytic film is strengthened, and the durability, antifogging durability and hydrophilicity retention of the antifogging and antifouling article are improved. If the temperature is lower than 20 ° C or the time is shorter than 3 minutes, the above effect is not sufficient and is not preferable. If the temperature is higher than 180 ° C, the organosilane may decompose, which is not preferable. Further, even if the time is longer than 3 hours, the effect is no longer improved, which is not preferable from the viewpoint of productivity.</p><p> If an organosilane single molecule equivalent layer is formed on the surface of the photocatalyst film, the antifogging durability and antifouling property are improved. This organosilane layer is gradually decomposed by external factors such as ultraviolet irradiation and temperature rise, and finally becomes a layer equivalent to a single molecule of SiOx, and antifogging durability and antifouling property are maintained.</p>

<p> It is clear that the antifogging and antifouling glass according to the present invention has excellent antifogging and antifouling performance and its maintainability, and also has good mechanical durability. Therefore, it is used for automobiles, construction and eyeglasses. It can be suitably used as glass.</p>

Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited to such Examples.

5 parts by weight of zirconium butoxide was added to 1 part by weight of ethyl acetoacetate, and the mixture was stirred at 30 ° C. for 2 hours (Liquid A). On the other hand, 50 parts by weight of tetraethoxysilane, 1000 parts by weight of 2-propanol, 2.5 parts by weight of 1N nitric acid, and 50 parts by weight of water were added, and the mixture was stirred at 30 ° C. for 2 hours (Liquid B). Solution A and solution B were mixed and cured by stirring at 50 ° C for 3 hours and then at 30 ° C for 1 day to obtain a sol solution for an alkaline blocking film.

A soda lime silicate glass plate (65 mm × 150 mm × 3 mm), which has been surface-polished and washed with a cerium oxide-based abrasive, ultrasonically cleaned in pure water, and dried, is immersed in the sol solution for an alkali blocking film. The glass plate was pulled up at a rate of 10 cm / min and the sol was applied. Then, this is dried at room temperature for several minutes and further heat-treated at 500 ° C. for 3 hours to form a flat and smooth silica-zirconia thin film (silica 92% by weight, zirconia 8% by weight) having a thickness of about 30 nm. I got a board.

Next, a method for producing a fluorine atom-doped titanium oxide film will be described. Stable by gradually dropping 248 mL (2.4 mol) of acetylacetone (AcAc) using a burette while stirring 353 mL (1.2 mol) of titanium tetraisopropoxide (Ti (OiPr) 4) and stirring for about 1 hour. Ti (AcAc)₂(OiPr)₂A complex solution was obtained (mother solution). On the other hand, a solution prepared by dissolving 0.75 g of trifluoroacetic acid (TFA) in 1398 mL of absolute ethanol was prepared. After adding the above mother liquor to this solution, the mixture was sufficiently stirred to obtain a uniform fluorine atom-doped titanium oxide film coating solution. The flat silica-zirconia thin film-coated soda lime silicate glass substrate is immersed in this coating solution for a fluorine atom-doped titanium oxide film, pulled up at a rate of 32 mm / min, dried at room temperature for 30 minutes, and then further 500 ° C. By firing in C for 30 minutes, an anatas-type titanium oxide film having a thickness of about 60 nm and having a fluorine atom doped in about 0.38% by weight was formed. In this way, a sample (glass substrate / silica-zirconia film / fluorine atom-doped titanium oxide film) was prepared.

Further, a SiOx monolayer film was formed on the surface of the fluorine atom-doped anatas-type titanium oxide film by the method described below. After setting the above (glass substrate / silica-zirconia film / fluorine atom-doped titanium oxide film) sample in a vacuum desiccator kept at 80 ° C, 200 μL of 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) was injected with a syringe. After holding in that state for 30 minutes, the temperature was raised to 100 ° C., and the desiccator was evacuated and heated for 30 minutes to remove unreacted TMCTS. By this method, a monolayer of TMCTS was formed on the titanium oxide film. Furthermore, the TMCTS film was oxidized and converted into a SiOx single molecule equivalent film by irradiating with light from a distance of 8 cm for 1 hour using a 500 W high-pressure mercury lamp. In this way, sample G (glass substrate / silica-zirconia film / fluorine atom-doped titanium oxide film / SiOx single molecule equivalent film) was obtained. The amount of fluorine atom doping in the titanium oxide film was 0.38% by weight, and the film thickness was about 60 nm. When the surface roughness was determined using the atomic force microscope, it was found that Ra was less than 0.2 nm and Sm = 420 nm, which was smooth.

(Comparative Example 1) A 10 cm square soda lime silicate glass plate (Na) as a substrate₂O about 13%, K₂O containing about 0.8%) was prepared. The surface of this glass plate was a smooth surface having an arithmetic mean roughness (Ra) of less than 0.2 nm and an average spacing (Sm) of irregularities of 400 nm.

Next, a method for coating a titanium oxide thin film by a dipping (sol-gel) method will be described. 85.6g (0.3mol) Titanium Tetraisopropoxide (Ti (OiPr))₄), 60.3 g (0.6 mol) of acetylacetone (AcAc) was gradually added dropwise using a burette, and the mixture was stirred for about 1 hour to stabilize Ti (AcAc).₂(OiPr)₂A complex solution was obtained (mother solution). This mother liquor was diluted 3.3 times with ethanol to prepare a coating solution. After immersing the soda lime silicate glass substrate in the coating liquid, a film was formed at a pulling rate of 4.6 cm / min, and firing was performed at 500 ° C. for 30 minutes. The obtained sample is used as sample A (glass substrate / titanium oxide film). As a result of analysis by X-ray diffraction, it was confirmed that the titanium oxide film of Sample A was amorphous. The thickness of the titanium oxide thin film of sample A was about 50 nm. As a result of measurement by an atomic force microscope, the surface of the titanium oxide film of sample A was a smooth surface having an arithmetic mean roughness (Ra) of less than 0.2 nm and an average unevenness interval (Sm) of 400 nm. .. A SiOx single molecule equivalent film was formed on the surface of this sample A in the same manner as in Example 1, and sample A'(glass substrate / titanium oxide film / SiOx single molecule equivalent film, Comparative Example 1) was obtained.

The degree to which these samples G and A'are continuously left in a room where people enter and leave without being exposed to ultraviolet rays and the surface becomes dirty and the antifogging property is reduced is evaluated by the degree of fogging when exhaled air is blown. (Breathing test). That is, the sample immediately after the surface is cleaned does not become cloudy even when exhaled, but when left indoors, dirt components in the atmosphere are adsorbed on the sample surface and become cloudy by the exhalation test. The time from the start of leaving the room to the start of fogging (anti-fog maintenance time) was used as an index of anti-fog maintenance. It can be said that the larger this value is, the higher the anti-fog maintenance property is. In addition, 0.8 mW / cm again for the sample that became cloudy in the exhalation test due to being left indoors.²The UV irradiation time (anti-fog recovery time) required for the exhalation test to stop fogging by continuously irradiating with ultraviolet rays of the same intensity (360 to 370 nm) was used as an index of anti-fog recovery. In addition, 0.8mW / cm²The ultraviolet (360 to 370 nm) irradiation intensity of is equivalent to 2 to 5 times the ultraviolet (360 to 370 nm) irradiation intensity from sunlight on the outdoor ground at 35 ° north latitude in winter, cloudy weather, and noon. It can be said that the smaller the anti-fog recovery time, the higher the anti-fog recovery property. Satisfying anti-fog retention for 24 hours or more and anti-fog recovery within 2 hours is required for many applications. More generally, a value obtained by dividing the anti-fog maintenance time by the anti-fog recovery time, that is, a value of [anti-fog maintenance time] / [anti-fog recovery time] of 40 or more is suitable as an anti-fog glass article. Can be used.

In addition, antifouling maintenance was performed by the following outdoor exposure test. A test glass plate was installed vertically outdoors in Itami City, Hyogo Prefecture, and an exposure test was conducted for 6 months in an environment that imitated the vertical surface under the eaves where rainwater flows down the surface of the test glass plate. The condition was evaluated visually according to the criteria shown in Table 1 below.

(Table 1) ========================= Evaluation Contamination status ------------------ ------- Almost no concern about dirt Slightly dirty, thin streaks can be seen Dirty, streaks are conspicuous × Stain is remarkable, streaks are quite conspicuous === ======================

Table 2 shows the various evaluation results of samples G and A'. Sample A'(Comparative Example 1) has good anti-fog and anti-fouling maintainability, but is inferior in anti-fog recovery. On the other hand, it is clear that Sample G (Example 1) has good anti-fog maintenance property and at the same time, the anti-fog recovery property is significantly improved. Further, it is clear that sample A'(Comparative Example 1) has low antifouling property, whereas sample G (Example 1) has good antifouling property.

Organo containing polyethylene oxide groups in the molecule on the surface of the sample (glass substrate / flat silica-zirconia film / fluorine atom-doped titanium oxide film) prepared in Example 1 before forming the film equivalent to SiOx single molecule. A silane layer (thickness about 4 nm) was formed.

1 mL of 0.1N acetic acid was added to 1 L of ethanol and stirred. 2 g of [methoxy (polyethyleneoxy) propyl] trimethoxysilane (SIM6492.7 manufactured by Chisso Co., Ltd., content 90%, molecular weight 460 to 590, ethylene oxide unit 6 to 9) in 798 g of this ethanol-based solution. The coating solution was prepared by adding and stirring at 30 ° C. for 1 hour.

The sample of Example 1 (glass substrate / flat silica-zirconia film / fluorine atom-doped titanium oxide film) was immersed in the above coating solution and pulled up at a speed of 5 cm / min to apply the solution. This was dried at 120 ° C. for 30 minutes, heat-treated, cooled to room temperature, and then lightly washed with pure water to form an organosilane layer (thickness: about 4 nm) containing a polyethylene oxide group in the molecule. This sample was irradiated with light from a distance of 8 cm for 24 hours using a 500 W high-pressure mercury lamp to oxidize the organosilane layer and convert it into a film equivalent to a single molecule of SiOx. This sample is used as sample J (= glass substrate / flat silica-zirconia film / fluorine atom-doped titanium oxide film / SiOx single molecule equivalent film). When the arithmetic mean roughness (Ra) and the average spacing (Sm) of the unevenness of this sample surface were determined using an atomic force microscope, it was a smooth surface with Ra of less than 0.2 nm and Sm of 430 nm. It was.

Table 2 shows the results of evaluating the antifogging and antifouling performance by the same method as described in Example 1. From this, it is clear that Sample J is an excellent anti-fog and anti-fouling glass.

As a substrate, a soda lime silicate glass plate having a size of 65 mm × 150 mm × 3 mm coated with a fluorine atom-doped flat silica film having a thickness of about 80 nm by a sol-gel method was prepared. The fluorine atom-doped flat silica film was formed by the following method.

Add 50 parts by weight of tetramethoxysilane, 530 parts by weight of ethanol, 530 parts by weight of 2-propanol, 2.5 parts by weight of 1N nitrate, 30 parts by weight of water and 1.4 g of trifluoroacetic acid (TFA), and stir at 50 ° C. for 2 hours. Further, the mixture was stirred and cured at 30 ° C. for 1 day to obtain a sol solution for an alkaline blocking film.

A soda lime silicate glass plate (100 mm × 100 mm × 3 mm), which has been surface-polished and washed with a cerium oxide-based abrasive, ultrasonically cleaned in pure water, and dried, is immersed in the sol solution for an alkali blocking film. The glass plate was pulled up at a rate of 30 cm / min and the sol was applied. Then, this was dried at room temperature for several minutes, and further heat-treated at 200 ° C. for 3 hours to obtain a glass plate having a thickness of about 90 nm and a fluorine atom-doped flat silica film doped with about 3% by weight of fluorine.

A photocatalyst film (titanium oxide silicon oxide) having a thickness of about 50 nm was formed on the fluorine atom-doped flat silica film-forming glass plate by the following method. That is, a commercially available photocatalyst coating solution ST-K03 (manufactured by Ishihara Sangyo Co., Ltd., titanium oxide fine particle content 5% by weight, inorganic binder 5% by weight) was diluted 4-fold by weight with ethanol. This liquid is formed on a glass plate on which the fluorine atom-doped flat silica film is formed by a spin coating method (1500 rpm, 10 seconds, liquid volume 4 ml), and heat-treated at 500 ° C. for 1 hour to form a photocatalytic thin film. Was formed. As a result of chemical analysis, it was confirmed that this photocatalytic thin film was composed of about 50% by weight of titanium oxide and about 50% by weight of silicon oxide. It was confirmed by the Rutherford backscattering method that the photocatalyst film was doped with about 0.1% by weight of fluorine presumed to have diffused from the fluorine atom-doped flat silica film. Further, a SiOx single molecule equivalent layer was formed on the photocatalyst film by the method described in Example 2.

This sample is used as sample N (= glass substrate / flat fluorine atom-doped silica film / fluorine atom-doped titanium oxide silicon oxide film / SiOx single molecule equivalent layer). When the arithmetic mean roughness (Ra) and the average spacing (Sm) of the unevenness of the sample surface were determined using an atomic force microscope, Ra was 1.2 nm and Sm was 20 nm.

Table 2 shows the results of evaluating the antifogging and antifouling performance by the same method as described in Example 1. From this, it is clear that Sample N is an excellent anti-fog and anti-fouling glass.

[Comparative Example 2] The 10 cm square soda lime silicate glass plate used in Example 1 was evaluated as sample O as it was without treatment, and the results are shown in Table 2. (Comparative example 2)

(Table 2) ================================ San Anti-fog Anti-fog Maintenance time Recovery time (a) / (B) After exposure test (hours) (hours) Antifouling condition evaluation (a) (b) -------------------------- ------ Example 1 G 40 0.25 160 2 J 60 0.6 100 3 N 48 0.3 160 Comparative Example 1 A'10 5 2 × 2 O 20 0-× ========= =======================