Photo-induced hydrophilic article and production method thereof

The present invention relates to a method of adhering a hydrophilic coating onto a substrate (eg, a glass sheet or a continuous float glass strip), and articles made by that method.

<u style="single">Reference related application</u> This application claims the rights of provisional US patent application Serial No. 60 / 040,566 filed on March 14, 1997, and US patent application Serial No. 08 / 899,257 filed on July 23, 1997 (currently). US Pat. No. 6,027,766), filed on April 1, 1999, entitled "Photocatalytically-Activated Self-Cleaning Appliances", Greenberg et al. CIP of US Patent Application Serial No. 09 / 282,943 by. All of these applications are incorporated herein by reference in their entirety. This application is a provisional United States entitled "Photo-Induced Hydrophilic Article and Method of Making Same" filed on February 28, 2001, incorporated herein by reference in its entirety. It claims the rights of patent application Serial No. 60 / 272,197.

In the next study, we will discuss general technical considerations regarding the present invention. However, the particular literature discussed here should not be considered to constitute "conventional technology" under 35 US patent law, and such acceptance is not accepted.

For many substances, such as glass substrates such as building windows, automotive transparency, and aircraft windows, the surface of the substrate can substantially produce surface contaminants such as common organic and inorganic surface contaminants. It is desirable not to have only a long time for good visibility. By convention, this has often meant cleaning these surfaces. This cleaning operation is typically performed by manually wiping the surface with or without a chemical cleaning solution. This method is laborious, time consuming and / or costly. Therefore, there is a need for a substrate that is easier to clean than existing glass substrates and has a surface that requires or less frequently performs such manual cleaning operations, especially glass substrates.

A semiconductor metal oxide is a self-cleaning coating that is activated by a photocatalyst (hereinafter referred to as "PA") when blended in the coating, that is, on the coating surface when exposed to a certain electromagnetic wave. It is known to provide a coating that interacts with organic pollutants and degrades or decomposes those pollutants. In general, the bibliography of patents and treatises on photocatalytic oxidation of organic compounds is "Bibliography of Work On The Photocatalytic Removal of Work On The Photocatalytic Removal of" by D. Blake. Hazardous Compounds from Water and Air), National Renewable Energy Laboratory (May 1994), updated October 1995 and October 1996.

Typically, these PA coatings are made thick enough to have sufficient photocatalytic activity to disintegrate or decompose organic contaminants on the coating in the shortest possible time. For example, WO 00/75087 has a minimum of 5x10^-3cm^-1Minutes^-1A coating that is activated by a photocatalyst having the photocatalytic activity of is described. Yet another PA coating is described, for example, in US Pat. Nos. 5,873,203, 6,027,766, and 6,054,227.

In addition to their self-cleaning properties, these PA coatings are typically hydrophilic, i.e. wettable. The hydrophilicity of the PA coating helps reduce fogging, i.e., the accumulation of water droplets on the coating. Accumulation of water droplets may reduce the transmission and visibility of visible light through the coated substrate. So far, this hydrophilicity has been associated with several factors, including increased surface roughness (wrinkles) on the coated surface and increased coated porosity. For example, US Pat. No. 6,103,363 states a hydrophilic photocatalytic activated self-cleaning coating with a preferred root mean square (RMS) surface roughness of 5 nm to 15 nm and a preferred porosity of 70% to 90%. Is described. However, this degree of surface roughness can make surface cleaning even more difficult, for example by providing small dents where dirt and dirt accumulate, or from a cleaning cloth rubbed over the surface. It can be even more difficult due to fiber catching or tearing. Moreover, increasing the porosity of the coating can provide grooves through which the underlying substrate can be chemically eroded.

Many PA self-cleaning coatings have been deposited by the sol-gel process to achieve the desired levels of coating thickness, photocatalytic activity, surface roughness, and coating porosity previously mentioned. In a typical sol-gel method, an uncrystallized colloidal suspension is coated on a substrate at or near room temperature and then heated to form a crystallization coating. For example, US Pat. No. 6,013,372 describes a hydrophilic photocatalytic self-cleaning coating formed by mixing photocatalytic particles in a layer of metal oxide and applying the mixture to a substrate by the sol-gel process. ing.

However, conventional sol-gel methods are economically or practically incompatible with certain application conditions or substrates. For example, in conventional float glass production, the float glass strip in the molten metal bath is too hot to accept the sol due to evaporation or chemical reaction of the solvent used in the sol. Moreover, the environment of the molten metal bath does not help with mobile machines such as spraying equipment required to apply the sol. Therefore, the sol must typically be applied after the float glass strip has exited the molten metal bath and cooled to near room temperature. The coated band must then be reheated to a temperature sufficient to crystallize the coating. Such cooling and reheating operations require substantial capital input in terms of equipment, energy and handling costs, significantly reducing manufacturing efficiency. In addition, reheating sodium-containing substrates such as soda, lime, and silica glass increases the chances of transferring sodium ions in the substrate towards the coating, which is referred to as "sodium ion poisoning" of the deposited coating. It has been mentioned in the past. The presence of these sodium ions may reduce or eliminate the photocatalytic activity of the self-cleaning coating. In addition, the sol-gel process typically produces a thick coating, eg, a thick coating of a few μs, which can adversely affect the optical and / or aesthetic properties of the coated article. Typically, as the thickness of the PA self-cleaning coating increases, the light transmittance and reflectance of the coating exceed a series of minimum and maximum values due to the optical interference effect. The color of the reflected and transmitted light of the coating varies due to these optical effects. Thus, a coating thick enough to provide the desired self-cleaning may have undesired optical properties.

<p> Therefore, it would be advantageous to provide a manufacturing article with a coating, especially a hydrophilic coating, and to provide a method of manufacturing the article in which at least some of those drawbacks are reduced or eliminated.</p>

<p> The present invention relates to articles of manufacture comprising at least one surface and a substrate having a hydrophilic coating, particularly a light-induced hydrophilic coating (defined below) deposited over at least a portion of the surface. The coating shall be deposited by a method selected from chemical vapor deposition (hereinafter referred to as CVD), spray pyrolysis, and / or magnetron sputtered vacuum deposition (hereinafter referred to as MSVD). Can be done. In one embodiment, the coating, eg, the outer surface of the coating, is equal to or greater than 0 nm, equal to or less than 4 nm, eg equal to or less than 3 nm, eg equal to or less than 2 nm. It is small and has a root mean square roughness in the range equal to or less than, for example, 1 nm. It is particularly advantageous if the substrate is a float glass strip and the coating is deposited in a molten tin bath by CVD during the manufacture of the float glass strip. As another special aspect of the present invention, the light-induced hydrophilic coating is 0 cm.^-1Minutes^-13x10 equal to or greater than^-3cm^-1Minutes^-1Equal to or less than, eg 2x10^-3cm^-1Minutes^-1Has photocatalytic activity in the range equal to or less than. In another aspect of the invention, the substrate is a floated glass strip located in a molten metal bath and the photoinduced hydrophilic coating has a thickness in the range greater than 0 Å and equal to or less than 500 Å. However, the light-induced hydrophilic coating is vapor-deposited in a molten metal bath by chemical vapor deposition. The present invention also relates to a method of producing such an article.</p>

<figref num="1">FIG. 1 is a cross-sectional view (not full size) of a portion of a substrate on which the photoinduced hydrophilic coating of the present invention is deposited.</figref><figref num="2">FIG. 2 is a side view (not the actual size) showing a coating process for applying the semiconductor metal oxide coating of the present invention to a glass band in a molten metal bath for manufacturing float method glass.</figref><figref num="3">FIG. 3 is a side sectional view (not the actual size) of the insulating glass unit incorporating the features of the present invention.</figref>

Very thin semiconductor metal oxide coatings, such as coatings greater than 0 Å and equal to or less than 500 Å, are thinner and much thinner than the coatings typically used to achieve photocatalytic self-cleaning. It was quite unexpectedly found that the photocatalytic activity of thin coatings maintains their hydrophilicity even when the activity is lower than that typically desired for self-cleaning coatings to decompose organic pollutants. That is, the photoactivity maintained by the thin semiconductor metal oxide coating, which may not be sufficient to have measurable or commercially acceptable photocatalytic self-cleaning activity, is the coating. Was found to be sufficient to be hydrophilic. This light-induced hydrophilicity reduces fogging and / or makes it easier to clean the coated article and allows, for example, to wipe off dirt and / or water droplet spots more easily than an uncoated article. In addition, photoinduced hydrophilicity thins the water, speeds drying and reduces water droplet spots. This is because the water does not tend to become droplets and leave spots. Dirt can also be removed more easily by simply rinsing the coating without wiping the coating by hand. Moreover, these very thin semiconductor metal oxide coatings are less prone to the unwanted optical problems associated with thicker photocatalytic self-cleaning coatings. It was also quite unexpectedly discovered that these very thin semiconductor metal oxide coatings can be made much smoother and denser than previously thought, while still maintaining their photoinduced hydrophilicity. An example of a suitable semiconductor metal oxide that can be used in the practice of the present invention is an oxide of titanium.

In one embodiment, the invention presents a photoinduced hydrophilic semiconductor metal oxide such as a titanium dioxide coating deposited on at least one surface of a substrate, covering at least a portion of the surface, by CVD, spray pyrolysis, or MSVD. Gives a substrate with a coating. The coating has a thickness in the range greater than 0 Å, equal to or less than 500 Å, eg equal to or less than 400 Å, eg equal to or less than 300 Å, and the outer surface of the coating is In general, it can have an RMS roughness equal to or greater than 0 nm, equal to or less than 2 nm, for example 1.9 nm or less, for example 1 nm or less. In the case of the coating of the present invention having a thickness of about 200 Å or less, the coating surface can be further reduced in smoothness, for example 5 nm or less, for example 4.9 nm or less, for example 4 nm or less, for example 3 nm or less, for example 2 nm or less, For example, it can have an RMS roughness of 1 nm or less. As a special aspect, the substrate is a float glass strip (ribbon) located in a molten tin bath.

In one embodiment, the invention provides an article consisting of a float glass strip having a light-induced hydrophilic coating deposited directly on at least one surface and at least a portion of the at least one surface. The photoinduced hydrophilic coating can be deposited directly on the float glass strip in the molten metal bath.

The present invention also provides an article consisting of a substrate having a light-induced hydrophilic coating deposited over at least one surface and at least a portion of the at least one surface. The substrate may be a float glass strip located in the molten metal bath, the photoinduced hydrophilic coating can have a thickness of 500 Å or less, and the photoinduced hydrophilic coating can be at least one by chemical vapor deposition in the molten metal bath. It can be deposited by covering the surface.

The present invention further provides an article consisting of a substrate having a light-induced hydrophilic coating deposited over at least one surface and at least a portion of the at least one surface. The photoinduced hydrophilic coating can be deposited by chemical vapor deposition at temperatures in the range of 500 ° C to 1200 ° C, and the photoinduced hydrophilic coating can have a thickness of 500 Å or less.

It provides a method for forming a light-induced hydrophilic coating that covers at least a portion of the substrate. The method provides substrates with first and second surfaces, one of which has tin diffused into it, and on at least one of the surfaces, chemical vapor deposition, spray pyrolysis, magnetron. Metal oxide precursors are deposited from the coating by a method selected from spatter vacuum deposition and the substrate is heated to a temperature sufficient to decompose the metal oxide precursors to a root-squared average coarse of 2 nm or less. Includes forming a photoinduced hydrophilic coating with a metal.

Another method of covering at least a portion of the substrate to form a photoinduced hydrophilic coating is to provide a float method glass strip in a molten metal bath and metal deposit directly onto the top surface of the glass strip by chemical vapor deposition. It consists of depositing an oxide precursor material and heating the glass strip to a temperature sufficient to decompose the metal oxide precursor material to form a photoinduced hydrophilic coating.

Yet another method of covering at least a portion of the substrate to form a photoinduced hydrophilic coating is to provide a substrate with at least one surface and CVD coat the metal oxide precursor material covering at least a portion of the at least one surface. The substrate is vapor-deposited by an apparatus and the substrate is heated to a temperature in the range of 400 ° C to 1200 ° C to decompose the metal oxide precursor material to form a photo-induced hydrophilic coating, which is still photo-induced hydrophilic. The coating consists of providing sufficient precursor material to have a thickness of 500 Å or less.

The present invention also relates to articles formed by the methods of the present invention.

As used here, "inner", "outer", "above", "below", "top", "bottom" Spatial or directional terms such as, etc. relate to the present invention as shown in the drawings. However, it will be understood that the present invention can also take a variety of different orientations and therefore such terms should not be considered as limiting. Furthermore, all numbers used in the present specification and claims to express size, physical characteristics, processing parameters, component amounts, reaction conditions, etc. are modified by the term "about" in any case. It should be understood as possible. Therefore, unless the opposite is instructed, the numbers given in the following specification and claims are approximate and depend on the desired nature required to be obtained by the present invention. It can be changed. At a minimum, it is not an attempt to limit the application of doctrine equivalent to the claims, but each number is given by referring to at least a large number of reported significant numbers and applying the usual rounding method. It should be regarded as a patent. Moreover, it should be understood that many of the ranges described herein are all inclusive of any small range contained therein. For example, the range "1-10" should be considered to include any small range (including those numbers) that falls between the lowest value of 1 and the highest value of 10. .. That is, all small ranges starting with a minimum value of 1 or more and ending with a maximum value of 10 or less, for example 5. A range such as 5 to 10 is included. Furthermore, the term "deposited over" or "provided over" as used herein is used above, but not necessarily in contact with the surface. Means to be. For example, a "covered" coating of a substrate does not preclude the presence of one or more other coating films of the same or different composition located between the deposited coating and the substrate. .. In addition, all% listed herein are by "weight" unless otherwise indicated. All photocatalytic activity values discussed herein have been determined by the conventional stearic acid test described in US Pat. No. 6,027,766, which is incorporated herein by reference. The value of all root mean square roughness is 1 μm²It can be determined by measuring the root mean square (RMS) with a nuclear microscope over the surface area of. Furthermore, it should be understood that the literature referred to here as "included as a reference" incorporates the whole.

Next, with respect to FIG. 1, an article 20 having the characteristics of the present invention is shown. Article 20 has a substrate 22 having a surface 21 over which at least a portion of the surface 21 is covered with a light-induced hydrophilic (hereinafter referred to as PH) coating 24 of the present invention. As used herein, the term "photo-induced hydrophilic coating" refers to a substance or coating that is photo-activated hydrophilic. By "photoactively hydrophilic" is meant a coating in which the contact angle of water droplets on the surface of the coating decreases over time as a result of exposing the coating to electromagnetic waves. For example, the contact angle can be reduced to a value less than 15 °, for example less than 10 °, to become superhydrophilic, for example 24 W / m on a PH coated surface.²Equal to 5 ° after 60 minutes exposure to UV light from a light source sold as UVA340 (trade name) by Q-Panel Co. in Cleveland, Ohio, arranged to have the intensity of Or less, eg equal to or less than 4 °, eg equal to or less than 35 °. The contact angle is further, for example equal to or less than 2 °, equal to or less than, for example, 1 ° when exposed to the light source longer or to different light sources and / or different illumination intensities. It can be reduced to a small value.

Although not to be considered as a limitation to the present invention, the PH coating of the present invention is considered to be photoactive or behave like photoactivity. Those skilled in the art will appreciate that the term "photoactive" or "photoactively" refers to the generation of light in a hole-electron pair when irradiated with radiation of a particular frequency. Examples of photoactive substances useful in the practice of the present invention include semiconductor metal oxides. Although photoactively hydrophilic, the coating 24 does not necessarily have to be photocatalytic to the extent that it becomes self-cleaning, i.e. like stains on the coating surface within a reasonable or economically useful time. It does not have to be photocatalytic enough to decompose organic substances.

In a broad embodiment of the invention, the substrate 22 may be made of any desired material with the desired optical properties. For example, the substrate 22 may be transparent to visible light. By "transparent" is meant having a transmittance greater than 0% and passing through the substrate 22 up to 100%. "Visible light" means electromagnetic energy in the range of 395 nm to 800 nm. Alternatively, the substrate 22 can be "translucent" or "transparent". "Translucent" means passing electromagnetic energy (eg, visible light) but diffusing it to the point where the object on the other side is not clearly visible. "Opaque" means that the visible light transmittance is 0%. Suitable materials for the substrate 22 include plastics [eg, polymethylmethacrylate, polycarbonate, polyurethane, polyethylene terephthalate (PET), or monomer copolymers for making them, or mixtures thereof], Includes ceramic or glass. The glass can be of any kind, eg, conventional float glass or flat glass, with any optical properties such as visible light transmittance, ultraviolet transmittance, infrared transmittance, and / or all. Any value of solar energy transmission may consist of any composition that has it. "Float glass" means glass formed by the conventional float method in which molten glass is placed on a molten metal bath and cooled under control to form a float glass band. The strips are then cut and / or molded and / or heat treated, if desired. Examples of float glass are US Pat. Nos. 4,466,562 and 4,671, It is described in the specification No. 155. For example, the glass may be conventional soda / lime / silicate glass, borosilicate glass, or lead glass. The glass may be "transparent glass", i.e. colorless or uncolored glass. Alternatively, the glass may be colored or separately colored glass. The glass may be non-tempered, heat treated or heat tempered glass. As used herein, the term "heat strengthened" means annealing, tempering, or at least partially quenching. Examples of suitable glass for substrate 12 are, but not limited to, US Pat. Nos. 4,746,347, 4,792,536, 5,240,886, 5,385,872, and 5,393,593 (these are for reference only). (Put it here). The substrate 22 may be of any desired size, eg length, width, shape, or thickness. For example, the substrate 22 may be a glass plate of a building window, a light window, a single glass plate of an insulating glass unit, or a laminate for conventional automobile windshield, side or rear windows, to name a few. , Sunroof, or transparent aircraft.

As shown in FIG. 1, the PH coating 24 may be deposited directly on the surface 21 of the substrate 22, that is, in surface contact. Even when a sodium-containing substrate such as soda, lime, or silica glass is used, the very thin PH coating of the present invention is due to the sodium in the substrate even when the coating is applied by the bath method described below. It has been found that it is not made non-hydrophilic. Therefore, it is possible to facilitate cleaning of soda, lime, and silica glass without using a sodium barrier layer between the glass and the PH coating of the present invention. In some cases, such a barrier layer may be used.

Alternatively, as described below, between the PH coating 24 and the substrate 22, one or more other layers or coatings, i.e. one or more functional coatings (eg, antireflection coatings) or sodium. An ion diffusion barrier layer can be interposed. For example, the PH coating 24 may be the outermost layer of the coating multilayer laminate present on the substrate 22, that is, the outermost layer, or the PH coating 24 may be the most in such a multilayer laminate. It may be embedded as one of the layers other than the outer layer. An "outer layer" is a layer that receives an excited electromagnetic wave, eg, ultraviolet light, that is sufficient to be photoactive hydrophilic but not necessarily photocatalytic to provide a coating with photoactivity. means. Preferably, the PH coating 24 is the outermost coating on the substrate 22.

As discussed above, the PH coating 24 does not need to have the level of photocatalytic activity of the conventionally known self-cleaning coating. For example, PH coating 24 is 0 cm.^-1Minutes^-15x10 equal to or greater than^-3cm^-1Minutes^-1±2×10^-3cm^-1Minutes^-1Equal to or less than, eg 4x10^-3cm^-1Minutes^-1Equal to or less than, eg 3x10^-3cm^-1Minutes^-1±2×10^-3cm^-1Minutes^-1Equal to or less than, eg 2x10^-3cm^-1Minutes^-1±2×10^-3cm^-1Minutes^-1Can have photocatalytic activity in the range equal to or less than.

The PH coating 24 is photoactive hydrophilic and can include any coating material that can be deposited by CVD, spray pyrolysis, or MSVD methods. For example, but not limited to the present invention, the PH coating 24 comprises one or more metal oxides, metal alloy oxides, or semiconductor metal oxides or metal alloy oxides, such as titanium oxides, silicon oxides. , Aluminum oxide, iron oxide, silver oxide, cobalt oxide, chromium oxide, copper oxide, molybdenum oxide, tungsten oxide, zinc oxide, zinc / tin alloy oxide, zinc tinate, titanic acid It can include, but is not limited to, strontium and mixtures or combinations thereof. Metal oxides and / or metal alloy oxides include metal oxides, superoxides, or suboxides.

One example of a PH coating 24 that is particularly useful in practicing the present invention is titanium dioxide. Titanium dioxide exists in amorphous and three crystalline forms, namely anatase, rutile, and brookite crystalline forms. Anatase phase Titanium dioxide exhibits strong photoactive hydrophilicity while having excellent resistance to chemical erosion and excellent physical durability. The rutile phase of titanium dioxide can also exhibit photoactive hydrophilicity. Mixtures or combinations of anatase and / or rutile and / or brookite and / or amorphous phases are also acceptable in the present invention as long as the combination exhibits photoactive hydrophilicity.

The PH coating 24 should be thick enough to provide an acceptable level of photoactive hydrophilicity. There is no absolute value that makes the PH coating 24 "acceptable" or "unacceptable". This is because whether or not a PH coating has an acceptable level of photoactive hydrophilicity depends largely on the purpose and conditions in which the PH coated article is used and the performance criteria selected to suit that purpose. Because. However, as discussed above, the thickness of the PH coating 24 that achieves photoactive hydrophilicity is the thickness required to achieve conventional commercially acceptable levels of photocatalytic self-cleaning activity. It can be much smaller than that. For example, the PH coating 24 can have a thickness in the range of 10 Å to 5000 Å, and the thicker coating in this range can have hydrophilicity as well as photocatalytic self-cleaning activity. As the coating becomes thinner in this range, the photocatalytic self-cleaning activity typically decreases. Photocatalytic self-cleaning activity may not be measurable as the coating thickness decreases in the range of 50 Å to 3000 Å, eg 100 Å to 1000 Å, eg 200 Å to 500 Å, eg 200 Å to 300 Å, but was selected. Hydrophilicity still exists in the presence of electromagnetic waves. 200 Å to 300 Å if the substrate 22 is a single float glass and the PH coating 24 has some anatase titanium dioxide PH coating formed directly by the CVD method over the single float glass. Thickness, 24 W / m on PH coated surface²When the PH coating is exposed to UV light from a UVA-340 light source with the intensity of 0-2 × 10 for the removal of stearic acid test film.^-3cm^-1Minutes^-1±2×10^-3cm^-1Minutes^-1, For example 1.8x10^-3cm^-1Minutes^-1~2.8×10^-3cm^-1Minutes^-1It has been found to provide photocatalytic activity in the range of. The PH coating also became superhydrophilic under the same UV light and had a water droplet contact angle in the range of 4 ° ± 2 ° to 7 ° ± 2 ° after being exposed to a UVA-340 light source for 60 minutes. It will be appreciated by those skilled in the art that the coating does not have to be of uniform thickness over its entire area. Therefore, the thickness values discussed here should be considered as the average thickness over the entire coating.

In another aspect of the invention, the outer surface of the PH coating 24 of the invention can be much smoother than the previous hydrophilic self-cleaning coating, but still retains its photoactive hydrophilicity. For example, the coating 24, especially the top of the coating, i.e. the outer surface, is in the range equal to or greater than 0 nm and less than 5 nm, even for thin coatings within the above range, such as 200 Å to 300 Å. It can have RMS roughness, eg, equal to or less than 4.9 nm, eg equal to or less than 4 nm, eg equal to or less than 3 nm, eg equal to 2 nm or It can be smaller, eg, equal to or less than 1 nm, and have an RMS roughness of, eg, 0.3 nm to 0.7 nm. For example, the 200 Å to 300 Å PH coating discussed above had an RMS surface roughness of 0.55 nm to 0.65 nm as measured by a nuclear microscope.

In yet another aspect of the invention, the PH coating 24 can have low visible light reflectance. The "visible light reflectance" used here is the conventional chromaticity coordinate specification (R).₁) Y (illumination C, observer angle 2 °) is mentioned. For example, PH coated articles are equal to or less than 10% to 25%, eg, 15% to 25%, eg, 19% to 24%, eg, 15% to 22%, eg, 25%, eg. , 23% or less, eg, can have visible light reflectance in the range equal to or less than 20%.

In yet another aspect of the invention, the PH coating 24 can be made more densely than the previous hydrophilic self-cleaning coating. For example, the PH coating 24 can be made substantially non-porous. By "substantially non-porous" is meant that the coating is dense enough to withstand conventional hydrofluoric acid droplet testing. In the droplet test, two drops of 0.5% by volume hydrofluoric acid (HF) aqueous solution are placed on a coated sample, and a conventional laboratory watch glass is placed on the sample at room temperature for 8 minutes. After 8 minutes, remove the watch glass and inspect the coating for damage. The dense PH coating 24 of the present invention provides better protection of the underlying substrate against chemical erosion than the conventional more porous self-cleaning coating and is more rigid than the self-cleaning coating applied by the conventional sol-gel method. , It is even less likely to be scratched.

According to the present invention, PH coatings having a thickness in the range of 10 Å to 500 Å, for example 400 Å or less, for example 200 Å to 300 Å, may be subjected to any one or more of spray pyrolysis, CVD, or MSVD. It can be formed on the substrate 22. In the spray pyrolysis method, the organic or metal-containing precursor is carried as an aqueous suspension, for example, an aqueous solution, and in the CVD method, it is carried in a carrier gas, for example, nitrogen gas, and sent toward the surface of the substrate 22. At the same time, the substrate 22 decomposes the precursor on the substrate 22 to a temperature high enough to form the PH coating 24. In the MSVD method, the metal-containing cathode target is sputtered under reduced pressure in an inert atmosphere or an oxygen-containing atmosphere to deposit a sputter coating covering the substrate 22. The substrate 22 is heated during or after coating to cause crystallization of the sputter coating to form the PH coating 24. Conventional spray thermal decomposition, CVD, and MSVD methods are well understood by those skilled in the art and therefore may not be described in detail here.

Each of these methods has advantages and disadvantages depending on the desired properties of the coating 24 and the type of glass manufacturing method. For example, in conventional float glass production, molten glass is poured onto a pool of molten metal, such as tin, in a molten metal (tin) bath to form a continuous float glass strip. The temperature of the float glass strip in a tin bath generally ranges from 1203 ° C (2200 ° F) at the inlet end of the bath to 592 ° C (1100 ° F) at the outlet end of the bath. The float glass strip is removed from its tin bath and annealed in a slow cooling furnace, i.e. controlledly cooled, and then cut into glass sheets of the desired length and width. The temperature of the float glass band between the tin bath and the annealing lehr is in the range of 480 ° C (896 ° F) to 580 ° C (1076 ° F), and the temperature of the float glass band in the slow cooling furnace. The temperature can be in the range of 204 ° C (400 ° F) to 557 ° C (1035 ° F) peaks. U.S. Pat. Nos. 4,466,562 and 4,671,155 (included here for reference) provide consideration for the manufacture of float glass.

The CVD and spray pyrolysis methods are preferred over the MSVD method in float glass production. This is because they are better compatible with coating continuous substrates such as float glass strips at elevated temperatures. Examples of CVD and spray pyrolysis coating methods are US Pat. Nos. 4,344,986, 4,393,095, 4,400,412, 4,719,126, 4,853,257, and 4,971,843 (these patents are included here for reference). It is described in).

In carrying out the present invention, one or more CVD coating devices can be used at several points in the float method glass strip manufacturing process. For example, a CVD coating device, while a float glass strip moves through a tin bath, after it leaves the tin bath, before it enters a slow cooling furnace, while it moves through a slow cooling furnace, or it It can be used after leaving the slow cooling furnace. Since the CVD method can cover moving float glass strips and yet can withstand the harsh environment involved in producing float glass strips, the CVD method allows floats in molten tin baths. It is particularly well suited to give a PH coating 24 to a float glass strip. U.S. Pat. Nos. 4,853,257, 4,971,843, 5,536,718, 5,464,657, and 5,599,387 (included here for reference) to cover a float glass strip in a molten tin bath. , CVD coating devices and methods that can be used in the practice of the present invention are described.

For example, as shown in FIG. 2, one or more CVD coating devices 50 can be placed at the tin bath 52 above the molten tin pool 54. While the float glass strip 56 moves through the tin bath 52, it sends the precursor material to the top surface of the strip 56. The precursor material decomposes to form the PH coating of the invention with photoactive hydrophilic activity. For example, the precursor material can be selected to decompose to form a semiconductor metal oxide, such as a crystalline metal oxide. An example of a precursor material used in the practice of the present invention that can form a titanium dioxide PH coating by the CVD method is titanium tetrachloride (TiCl).₄), Titanium tetraisopropoxide [Ti (OC)₃H₇)₄] (See below as TTIP), Titanium Tetrabutoxide, Titanium Tetraethoxydo [Ti (OC)₂H₅)₄] (Hereafter referred to as TTEt), and mixtures thereof, but not limited to them. Examples of carrier gases that can be used in the CVD process include, but are not limited to, air, nitrogen, oxygen, ammonia, and mixtures thereof. The concentration of the metal-containing precursor in the carrier gas is 0.01% to 0.4% by volume, for example 0.05% to 0.4% by volume, for example 0.05% to 2% by volume in the case of the metal-containing precursors listed above. , For example, in the range of 0.05% by volume to 1% by volume, but it will be appreciated by those skilled in the art that these concentrations can be varied in the case of other metal-containing precursors.

In the case of the CVD method (also the spray pyrolysis method discussed below), the temperature of those substrates during the formation of the PH coating 24 on the substrates 22 (eg, float method glass strip 56) is a metal-containing precursor material. It should be within the range of decomposition to form a coating with photoactive hydrophilic activity. The lower limit of this temperature range is greatly influenced by the decomposition temperature of the selected metal-containing precursor. For the titanium-containing precursors listed above, the lower limit temperature of the substrate 22 that provides sufficient decomposition of the precursor can be in the range 400 ° C (752 ° F) to 500 ° C (932 ° F). .. The upper limit of this temperature range is affected by the method of coating the substrate. For example, if the substrate 22 is a float glass strip 56 and the PH coating 24 is applied to the float glass strip 56 in the molten tin bath 52 during the manufacture of the float glass strip 56, the float glass strip 56 is 1000. May reach temperatures above ° C (1832 ° F). The float glass strip 56 can be increased or decreased in size, i.e. dimensioned (eg, stretched or compressed) at temperatures above 800 ° C (1472 ° F). If the PH coating 24 is applied to the float glass strip 56 before or during its size increase or decrease, the PH coating 24 will be applied while the float glass strip 56 is stretched or compressed. Each may crack or wrinkle. Therefore, when the shape of the float glass band 56 is stable (except for thermal shrinkage due to cooling), for example, in the case of soda, lime, and silica glass, it is lower than 800 ° C (1472 ° F), and the float glass. The PH coating can be applied when the band 56 reaches a temperature at which the metal-containing precursor can be decomposed, for example, above 400 ° C (752 ° F).

For spray pyrolysis, U.S. Pat. Nos. 4,719,126, 4,719,127, 4,111,150, and 3,660,061 specifications (included here for reference) refer to the conventional float method glass strip manufacturing process. The spray pyrolysis apparatus and method capable of this are described. Like the CVD method, the spray pyrolysis method is well suited for coating moving float glass strips, but the spray pyrolysis has a more complex device than the CVD device and is usually the outlet end of a tin bath. It is used between the part and the inlet end of the slow cooling furnace.

Examples of metal-containing precursors that can be used to form PH coatings by spray pyrolysis in the practice of the present invention include relatively water-insoluble organometallic reactants, especially metal acetylacetonate compounds. They are jet milled or wet milled to a particle size of less than 10 μm and suspended in an aqueous medium by using a chemical wetting agent. A suitable metal acetylacetone to form a titanium dioxide PH coating is titanylacetylacetone [TiO (C).₅H₇O₂)₂]. The relative concentration of metal acetylacetonate in the aqueous suspension is in the range of 5-40% by weight of the aqueous suspension. The wetting agent may be any relatively low foaming surfactant, including anionic, nonionic, or cationic compositions, but nonionic is preferred. The wetting agent is typically added in an amount of 0.24% by weight, but can range from 0.01% to 1% or more. The aqueous medium is preferably distilled water or deionized water. Aqueous suspensions for pyrolyzing and depositing metal-containing films are described in US Pat. No. 4,719,127 (which is included here for reference), especially column 2, lines 16-. It is described in column 4, line 48.

The lower surface of the float glass strip, which rests directly on the molten tin (commonly referred to as the "tin side"), has diffused tin on the surface, which in contact with the molten tin on the tin side. It gives a different tin absorption pattern than the opposite surface that was not (commonly referred to as the "air side"). The PH coating of the present invention may be formed on the air side of the float glass strip by the CVD method as described above while it is supported on tin, or on the air side of the float glass strip. It may be formed by the CVD or spray thermal decomposition method after it leaves the tin bath and / or it is formed by the CVD method on the tin side of the float glass strip after it leaves the tin bath. You may.

Regarding MSVD, US Pat. Nos. 4,379,040, 4,861,669, 4,900,633, 4,920,006, 4,938,857, 5,328,768, and 5,492,750 (included here for reference) contain glass substrates. An MSVD apparatus and method for sputter coating a metal oxide film on a substrate including the above is described. The MSVD method is generally incompatible with applying a PH coating on a float glass strip during its manufacture. This is because, among other things, the MSVD method requires decompression during the sputtering operation, which is difficult to form on a continuously moving float glass strip. However, the MSVD method is acceptable for depositing a PH coating 24 on a substrate 22, eg, a glass sheet. The substrate 22 is heated to a temperature in the range of 400 ° C (752 ° F) to 500 ° C (932 ° F) to crystallize the MSVD sputtered coating on the substrate during the deposition process, thereby allowing subsequent heating operations. Can be excluded. Heating the substrate in the spatter may be undesirable in some cases. This is because the additional heating operation during sputter reduces productivity. Alternatively, the sputter coating can be crystallized directly in the MSVD coating without post-heat treatment by using a high energy plasma, but again the MSVD coating tends to reduce productivity. Therefore, this is not the preferred method.

An example of a method of applying a PH coating using the MSVD method (particularly a PH coating with an RMS roughness of 2 nm or less at 300 Å or less) is that the coating is sputtered onto the substrate and the coated substrate is removed from the MSVD coating apparatus. After that, the coated substrate is heat-treated to crystallize the sputter coating to give a PH coating 24. For example, but not limited to the present invention, a titanium metal target is sputtered at a pressure of 5-10 mitol in an algo / oxygen atmosphere containing 5-50% oxygen, eg 20%, of the substrate 22. A titanium dioxide coating of the desired thickness can be sputter-deposited on top. The as-deposited coating is not crystallized. The coated substrate is removed from the coating device and heated to a temperature in the range of 400 ° C (752 ° F) to 600 ° C (1112 ° F) for a time sufficient to promote the formation of PH crystal morphology of titanium dioxide. , PH activation. For example, the coated substrate can be heated to a temperature in the range of 400 ° C (752 ° F) to 600 ° C (1112 ° F) for at least 1 hour. When the substrate 22 is a glass sheet cut from a float glass strip, the PH coating 24 can be sputter-deposited on the air side and / or the tin side.

The substrate 22 with the PH coating 24 deposited by CVD, spray pyrolysis, or MSVD method can then be subjected to one or more post-PH coating annealing operations. The temperature and time of annealing can be determined by the composition of the substrate 22, the composition of the PH coating 24, the thickness of the PH coating 24, and whether the PH coating 24 is in direct contact with the substrate 22 or one of the multilayer laminates on the substrate 22. It will be recognized that it is affected by several factors, including whether it is a layer or not.

When the substrate 22 contains sodium ions that can be transferred from the substrate 22 into the PH coating deposited on the substrate 22, when the PH coating is given by the CVD method, the spray pyrolysis method, or the MSVD method, those sodium ions are released. Interfering with or destroying the photoactive hydrophilicity of the PH coating by forming an inert compound while consuming titanium, for example by forming sodium titanate or causing photoexcited charge recombination. There is. Therefore, a sodium ion diffusion barrier (SIDB) layer can be deposited on the substrate before depositing the PH coating 24. Suitable SIDB layers are discussed in detail in US Pat. No. 6,027,766 (included here for reference) and are not discussed in detail here. When post-coating heating is used, sodium-containing substrates such as soda, lime, and silica glass preferably have a sodium barrier layer. When applying the PH coating of the present invention in a molten metal bath, the sodium barrier layer is optional.

The PH coating of the present invention preferably becomes photoactive hydrophilic when exposed to the ultraviolet range of the electromagnetic spectrum, for example, radiation in the range of 300 nm to 395 nm. UV sources include natural sources such as solar radiation, black light, or artificial light sources such as UV light sources such as the UVA-340 light source as described above.

As shown in FIG. 1, one or more additional coatings, such as the functional coating 46 (described below), are deposited on or over the substrate 22 on top of the PH coating 24 of the present invention. can do. For example, the functional coating 46 can be deposited over the main surface 60 of the substrate 22 on the opposite side of the surface 21. The functional coating 46 may be deposited by any conventional method, such as, but is not limited to, spray pyrolysis, CVD, MSVD, sol-gel method, and the like. For example, U.S. Pat. Nos. 4,584,206 and 4,900,110 (included here for reference) describe methods and equipment for depositing metal-containing films on the lower surface of a glass strip by chemical vapor deposition. Has been done. Such a known device can be placed downstream of the molten tin bath in float glass production to provide a functional coating on the underside of the glass strip, i.e. on the side opposite to the PH coating of the present invention. Alternatively, one or more other CVD coating devices can be placed in the tin bath to deposit a functional coating on or under the PH coating 24 of the float glass strip.

An example of the manufactured article of the present invention is shown in FIG. 3 in the form of an insulating glass (IG) unit 30. The insulating glass unit has a first glass plate 32 separated from a second glass plate 34 by a spacer assembly (not shown), the glass plate between the two glass plates 32, 34. It is held in place by a sealing material system so that a chamber is formed. The first glass plate 32 has a first surface 36 (surface number 1) and a second surface 38 (surface number 2). The second glass plate 34 has a first surface 40 (surface number 3) and a second surface 42 (surface number 4). The first surface 36 can be the outer surface of the IG unit, i.e. the surface exposed to the environment, and the second surface 42 can be the inner surface, i.e. the surface forming the inside of the structure. Examples of IG units are described in US Pat. Nos. 4,193,236, 4,464,874, 5,088,258, and 5,106,663 (included here for reference). As shown in FIG. 3, the PH coating 24 is preferably placed on the surface of No. 1 or No. 4, preferably on the surface of No. 1. The PH coating 24 reduces fogging, making it easier to clean and maintain the IG unit 30.

Optionally, one or more functional coatings 46 can be deposited over at least a portion of the surface of number 2, number 3, or number 4. As used herein, the term "functional coating" is a coating that covers a substrate and alters one or more physical properties of the substrate on which it is deposited, eg, optical, thermal, chemical, or mechanical properties. Is not intended to be removed from the substrate during subsequent processing. The functional coating 46 can have one or more functional coating films having the same or different compositions or functionality. As used herein, the term "layer" or "film" refers to the coating area of the desired or selected coating composition. The film may have uniform, non-uniform, or gradual compositional changes. The outer surface or portion (ie, the surface or portion farthest from the substrate), the inner surface or portion (ie, the surface or portion closest to the substrate), and the portion between the outer and inner surfaces have substantially the same composition. If so, the film is "uniform". The film has a substantially increasing fraction for one or more components and a substantially decreasing fraction for one or more other components as it moves from the inner surface to the outer surface and vice versa. If so, the film is "graded". If the film is non-uniform or non-gradual, then the film is "non-uniform." A "coating" is composed of one or more "films".

The functional coating 46 is, for example, an electrically conductive coating such as the electrically conductive heating window coating as described in US Pat. Nos. 5,653,903 and 5,028,759, or has a function such as an antenna. It can be a single film or multi-layer film coating that can be fulfilled. Similarly, the functional coating 46 can be a sun-regulating coating, such as a visible, infrared, or UV energy reflective or absorbing coating. Examples of suitable solar control coatings are US Pat. Nos. 4,898,789, 5,821,001, 4,716,086, 4,610,771, 4,902,580, 4,716,086, 4,806,220, 4,898,790, 4,834,857, 4,948,677. No. 5,059,295, and No. 5,028,759 and US Patent Application No. 09 / 058,440. Similarly, the functional coating 46 can be a low radioactive coating. A "low-radiation coating" allows visible wavelength energy, such as 400nm to 780nm, to pass through the coating, but reflects longer wavelength solar and / or thermal infrared energy and is embedded in the building. The purpose is typically to improve the thermal insulation of the window glass. "Low radioactivity" means less than 0.4, preferably less than 0.3, more preferably less than 0.2. Examples of low radioactive coatings are found, for example, in U.S. Pat. Nos. 4,952,423 and 4,504,109 and in the United Kingdom, GB2,302,102. The functional coating 46 may be a single layer or multilayer coating and may include one or more metals, non-metals, semimetals, semiconductors and / or alloys, compounds, composites, combinations or mixtures thereof. For example, the functional coating 46 can be a single layer metal oxide coating, a multilayer metal oxide coating, a non-metal oxide coating, or a multilayer coating. In addition, the functional coating can be an antireflection coating.

Examples of functional coatings suitable for use in the present invention are from PPG Industries, Inc. of Pittsburgh, PA, as those of the SUNGATE (registered trademark) and SOLARBAN (registered trademark) systems of the coating. It is commercially available. Such a functional coating is one or more comprising a dielectric or antireflection material, such as a metal oxide or an oxide of a metal alloy, which is preferably transparent or substantially transparent to visible light. It typically contains an anti-reflective coating film. The functional coating 46 can also include an infrared reflective film containing a reflective metal, such as a noble metal such as gold, copper, or silver, or a combination or alloy thereof, and further on and over the metal reflective layer. / Or an underlying film such as titanium or a barrier film, as is known in the art, located below can be included.

The functional coating 46 includes Magnetron Sputter Deposition (MSVD), Chemical Vapor Deposition (CVD), Spray Thermal Deposition (ie, Thermal Deposition Deposition), Atmospheric Pressure CVD (APCVD), Low Pressure CVD (LPCVD), Plasma Accelerated CVD (PECVD), Any conventional method such as plasma-assisted CVD (PACVD), thermal or electron beam deposition, cathode arc deposition, plasma spray deposition, and wet chemical vapor deposition (eg, sol gel, silver mirror deposition, etc.) Good, but not limited to them. When the functional coating is applied to the PH coating side of the substrate, it is preferable to apply the functional coating in a tin bath prior to the PH coating. If the functional coating is on the opposite side 60 of the PH coating, the functional coating is applied to the tin side of the substrate 22 by, for example, CVD or MSVD, after the tin bath of the float method, as discussed above. can do.

In the above study, the PH coating was applied over the air side of the substrate and the functional coating was applied over the tin side of the substrate, but the functional coating may be applied over the air side of the substrate. Will understand. For example, it may be applied to a float glass strip in a tin bath followed by a PH coating by covering the tin side of the substrate by a desired method, eg, a method as described above.

The advantage of the present invention over the sol-gel method of forming a self-cleaning coating is that it is thin and dense on the substrate, as opposed to the generally thicker porous self-cleaning coating obtained by the sol-gel coating method. It includes being able to form a good PH film. Since the PH coatings of the present invention are thin, eg, equal to or thinner than 500 Å, preferably equal to or thinner than 300 Å, they are aesthetically acceptable for use as transparent coatings on glass substrates. Can be done. Yet another advantage is that the PH coating method according to the invention eliminates the need to reheat the substrate after application of the coating or coating precursor, as required by the currently available sol-gel process. It is that you are. This makes the methods of the invention less costly and more efficient, eg, lower equipment costs, lower energy costs, and shorter manufacturing times (but not limited to them). Not only does it significantly reduce the opportunity for sodium ion transfer in the PH coating of the present invention, and thus significantly reduce sodium ion poisoning. Moreover, the methods of the present invention are easy to adapt to form PASC coatings on continuously moving substrates such as float glass strips, whereas currently available sol-gel methods are so easy. Cannot be adapted to.

The following examples of the present invention are given for illustration purposes and the present invention is not limited thereto.

On a 386 cm (152 ) float glass strip (3.3 mm thick transparent glass) that travels in a conventional tin bath at a speed of 1,229 cm / min (484 inches / min) by conventional CVD methods. , A 122 cm (48 ) wide PH coating of titanium dioxide with a thickness of 232 Å (determined by polarization and transmission data) was deposited. The coating was formed from a precursor material of 0.07 mol% titanium tetraisopropoxide in a nitrogen-containing carrier gas and applied at a glass band temperature of 659 ° C (1220 ° F). The coated band was then annealed, i.e. cooled at a controlled rate and cut into 7.5 cm (3 ) × 15 cm (6 ) sample pieces. The crystal structure of the vapor-deposited coating was determined to be anatase by X-ray diffraction. Coating determined by conventional stearic acid test 1.8 × 10^-3cm^-1Minutes^-1Has photocatalytic activity and reflectance (R)₁) Y = 19.43, x = 0.2741, y = 0.2774, and transmittance Y = 78.50, x = 0.3187, y = 0.3279, had chromaticity coordinates (illumination C, observer angle 2 °).

Dilute (pH 2.9) cleaning of a sample piece with a DART 210 cleaner commercially available from Madison Chemical Inc. of Medison, Indiana, to measure the photoactive hydrophilicity of the coated article. It was ultrasonically cleaned at 145 ° F for 20 minutes using an aqueous solution. The sample pieces were then rinsed with room temperature deionized water and then a second ultrasonic cleaning was performed in deionized water at 155 ° F for 10 minutes. The sample pieces were rinsed again with deionized water at room temperature and sprayed dry with compressed nitrogen. 24W / m of sample piece to UV radiation from UVA340 bulb²The contact angle of the water droplet was measured with time. The water droplet contact angle was measured with a Rame-Hart telephoto measuring device, type 102-00-115, with the sample in a horizontal (non-tilted) position. For each measured sample, the water droplet contact angle decreased from about 21 ° to 47 ° to about 4 ° to 11 ° after irradiation with UVA-340 for about 30 minutes, and about 3 ° to 7 after irradiation for about 60 minutes. It dropped to °.

Some sample pieces were subjected to a Taber abrasion test using a CS-10F disk with a load of 1000 g at 10 and 25 cycles. Using the Pacific Scientific XL211 HazeGuard System, the permeation cloudiness for each sample was determined to be 0.0. Five sample pieces were subjected to a flat plate rotational wear test according to ANSI Z26.1-1983 Test No. 18 method for wear resistance (1000 cycles, 500 g per flat plate), with an average of 2.4% diffused light. Gave an increase.

The sample pieces are subjected to several conventional test methods and their results are given in Table 1 below. Film degradation results are based on macroscopic observations and reflect color measurements. The contact angle results were determined as described above.

<tables num="1"><img file="JP2014133700A_D0001.tif" /></tables>

As shown in Table 1, the PH coating showed no deterioration of the film and maintained its photoinduced hydrophilicity after each test.

It will be readily appreciated by those skilled in the art that modifications can be made to the invention without departing from the concepts disclosed above. Therefore, the particular embodiments described in detail herein are for illustration purposes only and do not limit the scope of the invention. The scope of the present invention should be given to the entire scope of claims and any equivalent thereof.

<u style="single">Preferred embodiments of the present invention are as follows.</u><u style="single">1.</u><u style="single"> A substrate having at least one surface, and</u><u style="single"> It has a light-induced hydrophilic coating, which is deposited over at least a portion of the at least one surface.</u><u style="single"> The outer surface of the photoinduced hydrophilic coating has a root-mean square roughness equal to or less than 2 nm, and the photoinduced hydrophilic coating is selected from chemical vapor deposition, magnetron sputter vacuum deposition, and spray pyrolysis. Articles that have been deposited by the method used.</u><u style="single">2.</u><u style="single"> The contact angle of water droplets on the article is 24 W / m to cover the UVA340 radiation.</u>^{<u style="single">2</u>}<u style="single">The article according to 1, less than 15 ° after irradiation for 60 minutes with.</u><u style="single">3. </u><u style="single"> The contact angle of water droplets on the article is 24 W / m to cover the UVA340 radiation.</u>^{<u style="single">2</u>}<u style="single">The article according to 1, less than 10 ° after irradiation for 60 minutes.</u><u style="single">4. </u><u style="single"> The contact angle of water droplets on the article is 24 W / m to cover the UVA340 radiation.</u>^{<u style="single">2</u>}<u style="single">The article according to 1, less than 5 ° after irradiation for 60 minutes with.</u><u style="single">5. </u><u style="single"> The article according to 1, wherein the contact angle of water droplets on the article is equal to or less than 1 °.</u><u style="single">6. </u><u style="single"> The article according to 1, wherein the photoinduced hydrophilic coating has a thickness equal to or less than 500 Å.</u><u style="single">7. </u><u style="single"> The article according to 1, wherein the photoinduced hydrophilic coating has a thickness equal to or less than 400 Å.</u><u style="single">8. </u><u style="single"> The article according to 1, wherein the photoinduced hydrophilic coating has a thickness equal to or less than 300 Å.</u><u style="single">9. </u><u style="single"> The article according to 1, wherein the photoinduced hydrophilic coating has a thickness equal to or less than 200 Å.</u><u style="single">10. </u><u style="single"> The article according to 1, wherein the photoinduced hydrophilic coating has a thickness in the range of 50 Å to 500 Å.</u><u style="single">11. </u><u style="single"> Photoinduced hydrophilic coatings include titanium oxide, silicon oxide, aluminum oxide, iron oxide, silver oxide, copper oxide, tungsten oxide, zinc / tin alloy oxide, zinc tinate, molybdenum oxide, The article according to 1, which contains at least one metal oxide and / or metal alloy oxide selected from zinc oxide, strontium titanate, cobalt oxide, chromium oxide, and mixtures or combinations thereof.</u><u style="single">12. </u><u style="single"> The article according to 1, wherein the photoinduced hydrophilic coating contains titanium dioxide.</u><u style="single">13.</u><u style="single"> 12. The article according to 12, wherein the titanium dioxide is selected from the group consisting of anatase, rutile, brookite, amorphous, and mixtures or combinations thereof.</u><u style="single">14. </u><u style="single"> The article according to 1, wherein the light-induced hydrophilic coating is substantially non-porous.</u><u style="single">15. </u><u style="single"> The article according to 1, wherein the outer surface of the coating has a root mean square roughness equal to or less than 1 nm.</u><u style="single">16. </u><u style="single"> The article according to 1, wherein the outer surface of the coating has a root mean square roughness in the range of 0.2 nm to 0.7 nm.</u><u style="single">17. </u><u style="single"> The coating is 5x10</u>^{<u style="single">-3</u>}<u style="single">cm</u>^{<u style="single">-1</u>}<u style="single">Minutes</u>^{<u style="single">-1</u>}<u style="single">The article according to 1, which has a photocatalytic activity equal to or less than that of 1.</u><u style="single">18. </u><u style="single"> The coating is 3x10</u>^{<u style="single">-3</u>}<u style="single">cm</u>^{<u style="single">-1</u>}<u style="single">Minutes</u>^{<u style="single">-1</u>}<u style="single">The article according to 1, which has a photocatalytic activity equal to or less than that of 1.</u><u style="single">19. </u><u style="single"> The coating is 2x10</u>^{<u style="single">-3</u>}<u style="single">cm</u>^{<u style="single">-1</u>}<u style="single">Minutes</u>^{<u style="single">-1</u>}<u style="single">±2×10</u>^{<u style="single">-3</u>}<u style="single">cm</u>^{<u style="single">-1</u>}<u style="single">Minutes</u>^{<u style="single">-1</u>}<u style="single">The article according to 1, which has a photocatalytic activity equal to or less than that of 1.</u><u style="single">20. </u><u style="single"> The article according to 1, wherein the article has a visible light reflectance in the range of 15% to 25%.</u><u style="single">21. </u><u style="single"> The article according to 1, having at least one additional coating located between the light-induced hydrophilic coating and the substrate.</u><u style="single">22. </u><u style="single"> 21. The article according to 21, wherein the additional coating is a functional coating selected from the group consisting of a sodium ion diffusion barrier, a solar control coating, and an antireflection coating.</u><u style="single">23. </u><u style="single"> The article according to 1, wherein the substrate has a first surface and a second surface, has a coating deposited over at least a part of the first surface, and the second surface has tin diffused therein.</u><u style="single">24. </u><u style="single"> The article according to 1, wherein the substrate is a float glass strip and the deposition method is selected from chemical vapor deposition and spray pyrolysis.</u><u style="single">25. </u><u style="single"> The article according to 24, wherein the float glass strip is located in a molten metal bath and the deposition method is chemical vapor deposition.</u><u style="single">26. </u><u style="single"> The article according to 1, wherein the article is an integral or laminated window unit having an inner surface and an outer surface and has a light-induced hydrophilic coating deposited on the outer surface.</u><u style="single">27. </u><u style="single"> 1. The article is an insulating glass unit having surfaces numbered 1, 2, 3, and 4, wherein a light-induced hydrophilic coating is located on at least one of the surfaces numbered 1 or 4. Goods.</u><u style="single">28. </u><u style="single"> 27. The article of 27, having a functional coating located on at least one of the surfaces of number 2, number 3, or number 4.</u><u style="single">29. </u><u style="single"> The article according to 1, wherein the article is a transparent body of an automobile.</u><u style="single">30. </u><u style="single"> The article according to 1, wherein the article is a window of a building.</u><u style="single">31. </u><u style="single"> The article according to 1, wherein the article is an automobile transparent body having an inner surface, and a coating is deposited on the inner surface.</u><u style="single">32. </u><u style="single"> The coating has a thickness in the range of 200 Å to 300 Å, root mean square roughness equal to or less than 1 nm, and 3 × 10</u>^{<u style="single">-3</u>}<u style="single">cm</u>^{<u style="single">-1</u>}<u style="single">Minutes</u>^{<u style="single">-1</u>}<u style="single">The article according to 1, which contains titanium dioxide having a photocatalytic activity equal to or less than that of 1.</u><u style="single">33. </u><u style="single"> The article according to 1, wherein the substrate has a functional coating deposited over at least a portion of the substrate.</u><u style="single">34.</u><u style="single"> 33. The article according to 33, wherein the functional coating is a solar control coating.</u><u style="single">35. </u><u style="single"> The substrate has a first surface and a second surface, and has a light-induced hydrophilic coating deposited over at least a part of the first surface and a functional coating deposited over at least a part of the second surface. Articles listed in 1.</u><u style="single">36. </u><u style="single"> Float glass strips with at least one surface, and</u><u style="single"> It has a light-induced hydrophilic coating, which is deposited directly on at least a portion of the at least one surface.</u><u style="single"> An article in which the light-induced hydrophilic coating is deposited directly on a float glass strip in a molten metal bath.</u><u style="single">37.</u><u style="single"> A substrate having at least one surface, and</u><u style="single"> It has a light-induced hydrophilic coating, which is deposited over at least a portion of the at least one surface.</u><u style="single"> The light-induced hydrophilic coating is 3 x 10</u>^{<u style="single">-3</u>}<u style="single">cm</u>^{<u style="single">-1</u>}<u style="single">Minutes</u>^{<u style="single">-1</u>}<u style="single">Articles having photocatalytic activity equal to or less than.</u><u style="single">38. </u><u style="single"> A substrate having at least one surface, and</u><u style="single"> It has a light-induced hydrophilic coating, which is deposited over at least a portion of the at least one surface.</u><u style="single"> The substrate is a float method glass band located in a molten metal bath, the light-induced hydrophilic coating has a thickness of 500 Å or less, and the light-induced hydrophilic coating is formed by chemical vapor deposition in the molten metal bath. An article that is vapor-deposited over at least one surface.</u><u style="single">39.</u><u style="single"> A substrate having at least one surface, and</u><u style="single"> It has a light-induced hydrophilic coating, which is deposited over at least a portion of the at least one surface.</u><u style="single"> An article in which the photoinduced hydrophilic light is deposited by chemical vapor deposition at a temperature in the range of 500 ° C to 1200 ° C, and the photoinduced hydrophilic coating has a thickness of 500 Å or less.</u><u style="single">40. </u><u style="single"> In a method of covering at least a portion of a substrate to form a photoinduced hydrophilic coating.</u><u style="single"> Prepare a substrate having a first surface and a second surface, at least one of which has tin diffused into it.</u><u style="single"> Metal oxide precursors are deposited from the coating device on at least one of the surfaces by a method selected from chemical vapor deposition, spray pyrolysis, and magnetron sputter vacuum deposition.</u><u style="single"> The substrate is heated to a temperature sufficient to decompose the metal oxide precursor to form a photoinduced hydrophilic coating with a root-mean square roughness of 2 nm or less.</u><u style="single">A method for forming a light-induced hydrophilic coating, which comprises various steps.</u><u style="single">41.</u><u style="single"> 40. The coating device is a chemical vapor deposition coating device, and the metal oxide precursor is selected from titanium tetrachloride, titanium tetraisopropoxide, titanium tetraethoxydo, titanium tetrabutoxide, and mixtures thereof. Method.</u><u style="single">42. </u><u style="single"> 40. The method of 40, wherein the photoinduced hydrophilic coating comprises titanium dioxide.</u><u style="single">43. </u><u style="single"> The light-induced hydrophilic coating is 24 W / m for UV radiation with a contact angle of 340 nm for water droplets on the coated substrate.</u>^{<u style="single">2</u>}<u style="single">40. The method according to 40, which has a thickness of less than 15 ° after irradiation for 60 minutes at the intensity of.</u><u style="single">44. </u><u style="single"> 40. The method of 40, wherein the photoinduced hydrophilic coating has a thickness equal to or less than 300 Å.</u><u style="single">45. </u><u style="single"> 40. The method of 40, wherein the photoinduced hydrophilic coating has a thickness of 50 Å to 250 Å.</u><u style="single">46. </u><u style="single"> 40. The method of 40, wherein the coating device is a thermal decomposition coating device, comprising sending a suspension of a metal oxide precursor from the thermal decomposition coating device onto a first surface.</u><u style="single">47. </u><u style="single"> 40. The method of depositing a metal oxide precursor directly on the surface of a substrate.</u><u style="single">48. </u><u style="single"> The coating is 3x10</u>^{<u style="single">-3</u>}<u style="single">cm</u>^{<u style="single">-1</u>}<u style="single">Minutes</u>^{<u style="single">-1</u>}<u style="single">40. The method of 40, which has a photocatalytic activity equal to or less than.</u><u style="single">49. </u><u style="single"> Cover thickness in the range of 200 Å to 300 Å, root mean square roughness of 0.2 nm to 1.5 nm, and 3 × 10</u>^{<u style="single">-3</u>}<u style="single">cm</u>^{<u style="single">-1</u>}<u style="single">Minutes</u>^{<u style="single">-1</u>}<u style="single">40. The method of 40, which has a photocatalytic activity equal to or less than.</u><u style="single">50. </u><u style="single"> In a method of covering at least a portion of a substrate to form a photoinduced hydrophilic coating.</u><u style="single"> Float glass strips provided in a molten metal bath,</u><u style="single"> The metal oxide precursor material is deposited directly from the coating device onto the top surface of the glass strip by chemical vapor deposition, and then</u><u style="single"> The glass strip is heated to a temperature sufficient to decompose the metal oxide precursor material to form a light-induced hydrophilic coating.</u><u style="single">A method for forming a light-induced hydrophilic coating, which comprises various steps.</u><u style="single">51.</u><u style="single"> 50. The method of 50, comprising depositing a metal oxide precursor material to provide a photoinduced hydrophilic coating having a thickness of 500 Å or less.</u><u style="single">52.</u><u style="single"> In a method of forming a light-induced hydrophilic coating that covers at least a portion of a substrate.</u><u style="single"> Prepare a substrate with at least one surface and</u><u style="single"> A metal oxide precursor material is deposited from a CVD coating device over at least a portion of the at least one surface.</u><u style="single"> The substrate is heated to a temperature in the range of 400 ° C to 1200 ° C to decompose the metal oxide precursor material to form the photoinduced hydrophilic coating, and</u><u style="single"> The light-induced hydrophilic coating provides sufficient precursor material to have a thickness of 500 Å or less.</u><u style="single">A method for forming a light-induced hydrophilic coating, which comprises various steps.</u><u style="single">53.</u><u style="single"> Articles formed by the method described in 40.</u>

20 Goods 21 Substrate surface 22 Hypokeimenon 24 PH coating 30 Insulated glass unit 32 First glass plate 34 Second glass plate 36 First surface 38 Second surface 40 First surface 42 Second surface 46 Functional coating 50 CVD coating equipment 52 tin bath 56 Float glass strip 60 Main surface of the substrate