Visible-light-responsive photoactive coating, coated article, and method of making same

Visible light-responsive photoactive coating, coated product, and preparation method thereof

[0001] Cross-reference of related applications

[0002] This application is a partial continuation of U.S. Application No. 10/075, 316 (Greenberg et al., entitled "Photocatalytically activated self-cleaning appliances", submitted on February 14, 2002), the latter being in April 1999 The division of US Application No. 09/282,943 (now US Patent No. 6,413, 581) filed on the 1st, the latter being US Application No. 08/899,257 (now US Patent No. 6) filed on July 23, 1997 , 027, 766), the latter claims the priority of U.S. Provisional Application Serial No. 60/040, 566 filed on March 14, 1997, and all applications are hereby fully incorporated by reference into the present invention. This application also claims the priority of U.S. Provisional Application Serial No. 60/305, 057 filed on July 13, 2001, which is also fully incorporated herein by reference.

[0003] 1. Field of the invention

[0004] The present invention relates to a method for depositing a photoactive coating on a substrate (eg, a glass sheet or continuous float glass ribbon) to produce a photocatalytic and/or hydrophilic coating that exhibits photoactivity when irradiated with visible light Methods, and products made according to these methods.

[0005] 2. Technical problems

[0006] For many substrates, such as glass substrates such as architectural windows, automotive glass and aircraft windows, it is desirable for good visibility that the surface of the substrate is substantially free of surface contaminants for the longest possible duration. Such as ordinary organic and inorganic surface contaminants. Usually, this means that these surfaces are cleaned frequently. This cleaning operation is usually performed by manually wiping the surface with or without the help of chemical cleaning solutions. The solution is labor, time, and/or cost intensive. Therefore, there is a need for substrates with a surface that is easier to clean than existing glass substrates, especially glass substrates, so as to reduce the need or frequency of these manual cleanings.

[0007] Some semiconducting metal oxides are known to provide photoactive (hereinafter "PA") coatings. The term "photoactive" or "photoactively" refers to the photogenerating effect of a hole-electron pair when irradiated with rays of a specific frequency, usually ultraviolet ("uv") light. Above certain minimum thicknesses, these PA coatings are usually photocatalytic (hereinafter "PC"). "Photocatalysis" refers to a coating with self-cleaning properties, that is, when the coating is exposed to certain electromagnetic radiation, such as UV, it interacts with organic pollutants on the surface of the coating to degrade or decompose the organic pollutants. In addition to their self-cleaning properties, these PC coatings are also generally hydrophilic, that is, they are wetted by water with a water contact angle of generally less than 20 degrees. The hydrophilicity of the PC coating helps reduce fogging, that is, the accumulation of water droplets on the coating, and fogging reduces the visibility of visible light through and through the coated substrate.

[0008] The problem with these conventional PC coatings is that they are generally only photoactive or photocatalytic when exposed to ultraviolet (UV) light with a wavelength shorter than about 380 nanometers (nm). This means that the PC coating only uses about 3%-5% of the solar energy reaching the earth, which makes it necessary to use a UV light source (such as conventional mercury or ultraviolet lamps) to provide sufficient energy for photocatalysis.

[0009] In order to solve this problem, attempts have been made to modify conventional PC coatings to shift the light absorption band of the coating from the UV region of the electromagnetic spectrum to the visible region (400nm-800nm). For example, U.S. Patent No. 6,077,492 of Anpο et al. discloses a method for moving the light absorption band of a titanium oxide photocatalyst from the UV region to the visible light region by implanting high-energy ions of selected metal ions into the photocatalyst. . Subsequent studies on the ion implantation method have shown that the movement of the light absorption band to the visible region not only requires high-energy ion implantation, but also requires calcination of metal ion-implanted titanium oxide (Use of Visible Light. Second-Generation Titanium Oxide Photocatalysts) in oxygen. Prepared By the Application of AnAdvanced Metal Ion-Implantation Method (application of visible light. Through the application

The second generation of oxygen made by advanced metal ion implantation method, titanium photocatalyst Qi ί!), M. Anpo, PureApp 1. Chem., Vol. 72, No. 9, pp. 1787-1792 (2000)). EP 1,066,878 discloses a sol-gel method in which titanium dioxide is doped with a small amount of selected metal ions to move the light absorption band of titanium dioxide to the visible region.

[0010] However, these ion implantation and sol-gel coating methods are economically or practically unsuitable for certain use conditions or substrates. For example, in the conventional float glass process, the float glass ribbon in the molten metal bath is too hot to accept the sol due to the evaporation or chemical reaction of the solvent used for the sol. Conversely, if the sol is applied to a substrate below the specific temperature used to form the catalyst in crystalline form, the sol-coated substrate is reheated. Reheating to a temperature sufficient to calcinate the coating or form a crystalline photocatalyst may require considerable investment in equipment, energy, and processing costs, and therefore may significantly reduce production efficiency. In addition, the sodium-containing substrate, such as soda lime glass, is reheated to a temperature sufficient to calcinate the coating, which increases the possibility of sodium ions in the substrate to migrate to the coating. This migration can lead to the so-called "sodium ion poisoning" of the deposited coating. These sodium ions can reduce or destroy the photocatalytic activity of the PC coating. In addition, ion implantation and sol-gel methods generally produce thick coatings, eg, a few microns thick, which can adversely affect the optical and/or aesthetic properties of the coated article. Generally, as the thickness of the PC coating increases, the transmittance and reflectance of the coating experience a series of minimum and maximum values due to optical interference effects. The reflection and transmission colors of the coating also change due to these optical effects. Therefore, coatings thick enough to provide the required self-cleaning properties may have undesirable optical properties.

[0011] Therefore, it is advantageous to provide a method for manufacturing a PA coating with light absorption in the visible region that is compatible with conventional float glass processes and/or to reduce or eliminate at least some of the above-mentioned defects. Products.

[0012] Summary of the present invention

[0013] Provided is a method of depositing a precursor composition on at least a portion of the surface of a substrate by a CVD coating device to form a coating. The precursor composition includes a photoactive coating precursor material, such as a metal oxide or semiconducting metal oxide precursor material, and a light absorption band change precursor material. In one embodiment, the coating is deposited on a float glass ribbon in a bath of molten metal. In another embodiment, the coating is deposited on the float glass ribbon after leaving the molten metal bath but before entering the heat treatment equipment, such as an annealing furnace. The resulting coating leads at least to the hydrophilicity of the coating on the substrate, such as photoactive hydrophilicity, but also results in a photocatalytic activity sufficient to become a photocatalytic coating.

[0014] Another method of forming a photoactive coating having a light absorption band in the visible region of the electromagnetic spectrum includes depositing a precursor composition onto at least a portion of a float glass ribbon in a molten metal bath by a CVD coating device. The precursor composition includes at least one titanium dioxide precursor material. In one embodiment, the titanium dioxide precursor material includes titanium and oxygen, such as alkoxides such as but not limited to titanium methoxide, titanium ethoxide, titanium propoxide, titanium butoxide, and the like or isomers thereof, such as but not Limited to titanium isopropoxide, titanium tetraethoxide, and the like. In another embodiment, the titanium dioxide precursor material comprises titanium tetrachloride. The precursor composition also includes at least one material selected from the group consisting of Lo (Cr), Organic (V), Manganese (Mn), Copper (Cu), Iron (Fe), Magnesium (Mg), Gun (Sc), Armor (Y) ), ingot (Nb), aluminum (Mo), nail (Ru), duck (W), silver (Ag), lead (Pb), nickel (Ni), baht (Re), or one or more of them Any mixture or combination of other precursor materials. In one embodiment, the other precursor materials may be oxides, alkoxides, or mixtures thereof. All root mean square roughness values are those that can be determined by measuring the root mean square (RMS) roughness on a surface area of 1 square micrometer by atomic force microscopy. In addition, any mention of "herein incorporated into the present invention" shall be understood as being fully incorporated into the present invention.

[0015] Another method of the present invention includes depositing a sodium ion diffusion barrier layer on at least a portion of the substrate, depositing a photoactive coating on the barrier layer, and ion implanting one or more selected metal ions The photoactive coating is injected to form a photoactive coating having an absorption band including at least one wavelength in the range of 400 nm to 800 nm.

[0016] The article of the present invention includes a substrate having at least one surface and a substrate deposited on at least a portion of the surface of the substrate

coating. The coating includes a photoactive coating material, such as titanium dioxide, and at least one selected from the group consisting of Lo (Cr), Organic (V), Manganese (Mn), Copper (Cu), Iron (Fe), Magnesium (Mg), Bronze (Sc), Random (Y), Ingot (Nb), Aluminum (Mo), Nail (Ru), Duck (W), Silver (Ag), Lead (Pb), Nickel (Ni), Baht (Re), or Other materials including any mixture or combination of one or more of them. In one embodiment, the coating is deposited on the substrate by chemical vapor deposition.

[0017] The present invention provides the following technical solutions:

[0018] (1) A method of forming a coating, including the steps:

[0019] A precursor composition is deposited on at least a part of the surface of the substrate by a CVD coating device, the precursor composition comprising: (a) a precursor material of a metal oxide; and (b) before the light absorption band is changed The precursor material has at least one metal selected from the group consisting of Luo, mechanical, manganese, copper, iron, magnesium, bonnet, ingot, aluminum, nail, silver, lead, nickel, baht, and combinations thereof.

[0020] (2) The method of (1) above, wherein the metal oxide precursor material is a titanium dioxide precursor material.

[0021] (3) The method of (2) above, wherein the titanium dioxide precursor material is selected from titanium tetrachloride, titanium alkoxide, and mixtures thereof.

[0022] (4) The method of (3) above, wherein the titanium dioxide precursor material is selected from titanium isopropoxide and titanium tetraethoxide.

[0023] (5) The method of (1) above, wherein the material (b) is designed to change the light absorption band of the coating to include at least a portion of visible electromagnetic waves that are not in the light absorption band of the coating without material (b) Spectrum.

[0024] (6) The method of (1) above, wherein the material (b) is designed to change the light absorption band of the coating to include at least one wavelength in the range of 400nm-800nm.

[0025] (7) The method of (1) above, wherein the material (b) is at least partially soluble in the material (a).

[0026] (8) The method of (1) above, wherein the substrate is a float glass ribbon and the method includes depositing a precursor material on the float glass ribbon.

[0027] (9) The method of (1) above, wherein the substrate is a float glass ribbon in a molten metal bath and the method includes depositing a precursor material on the float glass ribbon in the metal bath.

[0028] (10) The method of (8) above, wherein the float glass ribbon is located between the molten metal bath and the annealing furnace.

[0029] (11) The method of (1) above, wherein the coating is photocatalytic when exposed to electromagnetic energy in the range of 400nm-800nm.

[0030] (12) The method of (1) above, wherein the coating is photoactive and hydrophilic when exposed to electromagnetic energy in the range of 400nm-800nm.

[0031] (13) A method of forming a photoactive coating whose light absorption band includes at least a part of the visible region of the electromagnetic spectrum, including the steps:

[0032] The precursor composition is deposited on at least a portion of the float glass ribbon in the molten metal bath by a CVD coating equipment, the precursor composition comprising:

[0033] Titanium dioxide precursor material; and having at least one metal selected from the group consisting of Luo, mechanical, manganese, copper, iron, magnesium, gunmetal, ingot, aluminum, nail, silver, lead, nickel, baht, and mixtures thereof Other precursor materials.

[0034] (14) The method of (11) above, wherein the titanium dioxide precursor material is selected from titanium tetrachloride and titanium alkoxide.

[0035] (15) The method of (14) above, wherein the titanium dioxide precursor material is selected from titanium isopropoxide and titanium tetraethoxide.

[0036] (16) The method of (13) above, including heating the substrate to a temperature sufficient to decompose the titanium dioxide precursor material and other precursor materials to form a photoactive coating.

[0037] (17) The method of (13) above, wherein the photoactive coating is photocatalytic when exposed to electromagnetic energy from 400 nm to 800 nm.

[0038] (18) The method of (13) above, wherein the photoactive coating is light when exposed to electromagnetic energy of 400nm-800nm.

Active hydrophilic.

[0039] (19) The method of (13) above, including depositing sufficient precursor composition so that the photocatalytic coating has a thickness of 50 angstroms to 2000 angstroms.

[0040] (20) The method of (13) above, comprising depositing an intermediate layer between the belt and the photocatalytic coating.

[0041] (21) The method of (20) above, wherein the intermediate layer is an anti-reflection layer.

[0042] (22) The method of (21) above, wherein the anti-reflection layer contains at least one of aluminum oxide, tin oxide, indium oxide, silicon oxide, silicon oxycarbide, and silicon oxynitride.

[0043] (23) The method of (20) above, wherein the intermediate layer is a sodium ion diffusion barrier layer.

[0044] (24) The method of (23) above, wherein the barrier layer includes silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, aluminum oxide, fluorine-doped aluminum oxide, aluminum nitride, and mixtures thereof At least one.

[0045] (25) A product, including:

[0046] a substrate having at least one surface; and

[0047] a coating deposited on at least a portion of the surface of the substrate,

[0048] Wherein the coating contains titanium dioxide and at least one selected from the group consisting of Luo, mechanical, manganese, copper, iron, magnesium, gunmetal, armor, ingot, aluminum, nail, silver, lead, nickel, baht, and mixtures thereof Other materials, and

[0049] Where the coating is deposited on the substrate by the following method, the method comprising the following steps:

[0050] A precursor composition is deposited on at least a portion of the surface of the substrate by a chemical vapor deposition coating device, the precursor composition comprising: (a) a precursor material of titanium dioxide; and (b) a light absorption band Change the precursor material, the precursor material has at least one selected from the group consisting of Luo, mechanical, manganese, copper, iron, magnesium, gunmetal, armor, ingot, aluminum, nail, silver, lead, nickel, baht, and combinations thereof metal.

[0051] (26) The article of (25) above, wherein the substrate is selected from glass, plastic, and ceramic.

[0052] (27) The article of (25) above, wherein the article is a heat-insulating glass unit and the substrate is at least one pane of the heat-insulating glass unit.

[0053] (28) The article of (25) above, wherein the substrate is selected from annealed glass, tempered glass, and heat strengthened glass.

[0054] (29) The article of (25) above, wherein the article is an architectural transparent body.

[0055] (30) The article of (25) above, wherein the coating is deposited directly on the surface of the substrate.

[0056] (31) The article of (25) above, wherein the coating contains at least part of titanium dioxide in anatase phase.

[0057] (32) The article of (25) above, wherein the coating contains at least part of the rutile titanium dioxide.

[0058] (33) The article of (25) above, wherein the substrate includes at least one surface in which tin is diffused.

[0059] (34) The article of (25) above, wherein the coating has a thickness of 50 angstroms to 2000 angstroms.

[0060] (35) The article of (25) above, wherein the substrate is a float glass ribbon.

[0061] (36) The article of (25) above, comprising at least one intermediate layer located between the surface of the substrate and the coating.

[0062] (37) The article of (36) above, wherein the intermediate layer is an anti-reflection layer.

[0063] (38) The article of (36) above, wherein the intermediate layer is a sodium ion diffusion barrier layer.

[0064] (39) The article of (37) above, wherein the anti-reflection layer contains at least one of aluminum oxide, tin oxide, indium oxide, silicon oxide, silicon oxycarbide, silicon oxynitride, and mixtures thereof.

[0065] (40) The article of the above (38), wherein the barrier layer comprises tin oxide, silicon oxide, titanium oxide, zirconium oxide, fluorine-doped tin oxide, aluminum oxide, magnesium oxide, zinc oxide, diamond oxide, and sulphur oxide , Iron oxide, and at least one of its mixtures.

[0066] Description of the drawings

[0067] FIG. 1 is a cross-sectional view (not to scale) of a part of the substrate on which the photoactive coating of the present invention is deposited;

[0068] FIG. 2 is a side view (not to scale) of a coating process for applying the photoactive metal oxide coating of the present invention to a glass ribbon in a molten metal bath for a float glass process; and

[0069] FIG. 3 is a side view (not to scale) of an insulating glass unit incorporating the features of the present invention.

[0070] Description of the invention

[0071] The spatial or directional terms used herein, such as "inner", "sunset", "above", "below", "top", "bottom", etc. relate to the present invention as shown in the accompanying drawings. However, it can be understood that the present invention can present various alternative orientations, and therefore, these terms cannot be regarded as limiting. In addition, all numbers representing dimensions, physical properties, process parameters, component amounts, reaction conditions, etc. used in and in the claims should be understood to be modified by the term "about" in all cases. Therefore, unless stated to the contrary, the numerical values given in the following and in the claims are approximate values that can be varied according to the required performance to be obtained by the present invention. At least, and not intended to limit the application of the principle of equivalence to the scope of the claims, each value should at least be interpreted according to the recorded significant figures and through the application of ordinary rounding techniques. In addition, all ranges disclosed herein should be understood to include any and all sub-ranges contained therein. For example, the range "1-10" should be considered to include any and all sub-ranges between (and inclusive) a minimum value of 1 and a maximum value of 10; that is, starting with a minimum value of 1 or more and ending with 10. All sub-ranges ending at or lower, for example, 5. 5-10. In addition, the term "deposited on" or "provided on" as used herein refers to deposition or provision on a surface but not necessarily surface contact. For example, the coating "deposited on the substrate" does not exclude the presence of one or more other coating films with the same or different composition between the deposited coating and the substrate. In addition, all percentages disclosed herein are "weight" unless expressed to the contrary. All root mean square roughness values are those that can be determined by atomic force microscopy by measuring root mean square (RMS) roughness on a surface area of 1 square micrometer. In addition, all mentioned "incorporated into the present invention by reference" are hereby understood as being fully incorporated into the present invention.

[0072] Referring now to FIG. 1, an article 20 having the characteristics of the present invention is shown. The article 20 includes a substrate 22 having a first surface 21 and a second surface 60. The substrate 22 does not limit the present invention and can be any material having any desired characteristics, such as an opaque or transparent substrate. "Transparent" means that the visible light transmittance is greater than 0% to 100%. "Opaque" refers to having a visible light transmittance of 0%. Visible light refers to electromagnetic energy with a wavelength of 400 nanometers (nm) to 800 nm. Examples of suitable substrates include, but are not limited to, plastic substrates (such as polyacrylate, polycarbonate, and polyethylene terephthalate (PET)); metal substrates; glazed or ceramic substrates Material; glass substrate; or a mixture or combination thereof. For example, the substrate may be conventional uncolored soda lime glass, that is, "transparent glass", or may be colored or otherwise colored glass, borosilicate glass, leaded glass, tempered, untempered , Annealed, or thermally strengthened glass. The glass can be of any kind, such as conventional float glass, flat glass, or float glass ribbon, and can have any optical properties, such as any value of visible transmission, ultraviolet transmission, infrared transmission, and/or total solar energy transmission Any composition. The types of glass suitable for the present invention are described in, for example, U.S. Patent Nos. 4, 746, 347; 4, 792, 536; 5, 240, 886; 5, 385, 872; and 5, 393, 593, but this is not considered limiting. For example, the substrate 22 may be a float glass tape, a glass lattice of a building window, a skylight, a window pane of a heat-insulating glass unit, a mirror, a shower door, glassware (such as a glass table top, or a glass cabinet, etc.), or Laminates used in conventional car windshields, side or rear windows, car roofs, or aircraft glass windows, to name a few.

[0073] The photoactive modified (hereinafter "PM") coating 24 of the present invention can be deposited on at least a portion of the substrate 22, such as on all or a portion of the main surface of the substrate 22, such as on all or a portion of the surface 21 or On surface 60. In the embodiment given, the PM coating 24 is on the surface 21 as shown. As used herein, the term "photoactive modified" refers to a material or coating that is photoactive and includes at least one additive or dopant that is used for mobile and / Or widen the light absorption band of the material. "Light absorption band" refers to being absorbed by the material to make the material

The range of photoactive electromagnetic radiation. The PM coating 24 can be photocatalytic, photoactive hydrophilic, or both. "Photoactive hydrophilic" refers to a coating in which the contact angle of water droplets on the coating decreases with time due to exposure of the coating to electromagnetic radiation in the light absorption band of the material. For example, the contact angle can be reduced to a value below 15 degrees, such as a value below 10 degrees, after 60 minutes of exposure to radiation in the light absorption band of the material having an intensity of 24 W/m? on the surface of the PM coating. Becomes super-hydrophilic, for example, drops below 5 degrees. Although photoactive, the coating 24 need not be photocatalytic, so that it is self-cleaning, that is, it is not sufficiently photocatalytic to decompose the organic material on the coating surface within a reasonable or economically useful time. Such as grime.

[0074] The PM coating 24 of the present invention includes (1) a photoactive coating material and (2) additives or dopants, which broaden or shift the light absorption of the coating compared with the coating without the dopant material band. The photoactive coating material (1) includes at least one metal oxide, such as, but not limited to, one or more metal oxides or semiconducting metal oxides, such as various titanium oxide, silicon oxide, aluminum oxide, iron oxide, Silver Oxide, Diamond Oxide, Luo Oxide, Copper Oxide, Duck Oxide, Zinc Oxide, Zinc Oxide/Tin Oxide, Titanate Saw, and mixtures thereof. Metal oxides may include metal oxides, super-oxides or suboxides. The metal oxide may be crystalline or at least partially crystalline. In an exemplary coating of the present invention, the photoactive coating material is titanium dioxide. Titanium dioxide exists in an amorphous form and three crystalline forms, namely, anatase, rutile and brookite crystalline forms. Anatase titanium dioxide is particularly useful because of its strong light activity, while also having excellent chemical resistance and excellent physical durability. However, the combination of rutile phase or anatase and/or rutile phase with brookite and/or amorphous phase is also acceptable for the present invention.

[0075] The light absorption band widening or shifting material (2) may broaden or shift the light absorption band of the resulting coating to at least partially expand into, or further expand into the visible region of the spectrum (ie, broaden or shift the light absorption band Any material that includes at least one wavelength in the range of 400nm-800nm that is not in the light absorption band of the coating without the dopant material (2)). In an exemplary embodiment, the material (2) includes at least one of Lo (Cr), Organic (V), Manganese (Mn), Copper (Cu), Iron (Fe), Magnesium (Mg), and Blow (Sc) , Armor (Y), ingot (Nb), aluminum (Mo), nail (Ru), duck (W), silver (Ag), lead (Pb), <(Ni), baht (Re), or any of them Any mixture or combination of one or more. The amount of material (2) present in the PM coating 24 is sufficient to widen or move the light absorption band of the coating 24 to at least partially expand into, or further expand into the visible area without adversely affecting the desired coating properties, such as, Reflectance, transmittance, color, etc. In addition, in the present invention, the material (2) does not have to be concentrated on or near the coating surface 21, but can be deposited such that it is dispersed or introduced into the body of the coating 24.

[0076] The PM coating 24 should be thick enough to provide an acceptable degree of photoactivity for the desired purpose, such as photocatalytic activity and/or photoactive hydrophilicity. There is no absolute value that makes the PM coating 24 "acceptable" or "unacceptable", because whether the PM coating 24 has an acceptable degree of photoactivity greatly depends on the purpose and conditions when the PM coated article is in use. And the selection of performance standards that match the purpose varies. However, the thickness required to achieve the photoactive hydrophilic PM coating 24 may be significantly lower than the thickness required to achieve a commercially acceptable level of photocatalytic self-cleaning activity. For example, in one embodiment, the PM coating 24 may have a thickness of 10 angstroms to 5000 angstroms, where a thicker coating in this range may have photocatalytic self-cleaning activity for at least a certain period of time, and hydrophilicity. As the coating becomes thinner in this range, the photocatalytic self-cleaning activity generally decreases in terms of performance and/or duration. As the coating thickness decreases in the range such as 50 angstroms to 3000 angstroms, such as 100 angstroms to 1000 angstroms, such as 200 angstroms to 600 angstroms, such as 200 angstroms to 300 angstroms, the photocatalytic self-cleaning activity may not be measurable but the photoactivity Hydrophilicity can still exist in the presence of selected electromagnetic radiation as within the light absorption band of the material.

[0077] In another aspect of the present invention, the outer surface 25 of the PM coating 24 of the present invention can be smoother than the previous self-cleaning coating, while still maintaining its photoactive hydrophilicity and/or photocatalytic activity. For example, the PM coating 24, especially the top of the coating or

7nmof The outer surface 25 may have less than 5nm, such as less than 4.9nm, such as less than 4nm, such as less than 3nm, such as less than 2nm, such as less than lnm, such as 0.3nm-0. 7nm RMS surface roughness (even for the above range, such as thin coatings within 200-300 angstroms).

[0078] In another aspect of the present invention, the PM coating 24 can become more dense than previously known hydrophilic, self-cleaning coatings. For example, the PM coating 24 may be substantially non-porous. "Substantially non-porous" means that the coating is dense enough so that the coating can withstand the conventional hydrofluoric acid test, in which a drop of 0.5% by weight (wt. %) of hydrofluoric acid (HF) aqueous solution is placed at room temperature Coat and cover with watch glass for 8 minutes (mins)_o The HF was then rinsed off and the coating was visually inspected for damage. Another HF immersion test is described in Industrial Engineering Chemistry & Research, Vol. 40, No. 1, page 26, 2001 (Charles Greenberg), which is incorporated herein by reference. The denser PM coating 24 of the present invention provides more protection to the underlying substrate from chemical attack than the previous more porous self-cleaning coating, and is harder than the previous self-cleaning coating using sol-gel And more scratch resistant.

[0079] The PM coating 24 may be directly deposited on the surface 21 of the substrate 22 shown in FIG. 1, that is, on the surface in contact therewith. Even for substrates containing sodium, such as soda lime glass, when the coating is applied by the following in-bath method, for example, the thin PM coating 24 of the present invention below 1000 angstroms should not change due to the sodium in the substrate. To be non-photoactive. Therefore, without using the sodium barrier layer between the glass and the PM coating 24 of the present invention, soda lime glass that can be cleaned more easily can be manufactured. If necessary, such a barrier layer can be used.

[0080] Alternatively, one or more other layers or coatings may be inserted between the PM coating 24 and the substrate 22. For example, the PM coating 24 may be the outer or outermost layer of a multi-layered coating present on the substrate 22 or the PM coating 24 may be embedded in such a multilayer as one of the layers other than the outermost layer. Inside. "Outer layer" refers to a layer that receives sufficient excitation electromagnetic radiation, such as radiation within the light absorption band of the layer material, so as to provide sufficient photoactivity so that it is at least photoactive and hydrophilic if it does not have to be photocatalytic. coating. In one embodiment, the PM coating 24 is the outermost coating on the substrate 22.

[0081] The PM coating 24 of the present invention can be formed on the substrate 22 by any conventional method, such as ion implantation, spray pyrolysis, chemical vapor deposition (CVD), or magnetron sputtering vacuum deposition (MSVD). In the ion implantation method, metal ions are injected into the coating by high-voltage acceleration. In the spray pyrolysis method, there are (1) metal oxide precursor materials, such as titanium dioxide precursor materials, and (2) at least one light absorption band change precursor material, that is, dopant materials (such as organic metal The organic or metal-containing precursor composition of the precursor material) is carried in an aqueous suspension, such as an aqueous solution, and directed to the surface of the substrate 22, while the substrate 22 is at a sufficiently high temperature to decompose the precursor composition And forming a PM coating 24 on the substrate 22. In the CVD method, the precursor composition is carried in a carrier gas, such as nitrogen, and directed to the substrate 22. In the MSVD method, one or more metal-containing cathode targets are sputtered in an inert or oxygen-containing atmosphere under reduced pressure to deposit a sputtered coating on the substrate 22. The substrate 22 may be heated during or after the coating process to crystallize the sputtered coating to form the PM coating 24. For example, one cathode can be sputtered to provide the metal oxide precursor material (1) and the other cathode can be sputtered to provide the dopant material (2). Alternatively, a single cathode that has been doped with the desired dopant material may be sputtered to form the PM coating 24.

[0082] Each method has advantages and limitations, depending on the desired characteristics of the PM coating 24 and the type of glass manufacturing process. For example, in a conventional float glass process, molten glass is poured into a pool of molten metal (such as tin) in a bath of molten metal (such as tin) to form a continuous float glass ribbon. The temperature of the float glass ribbon in the tin bath is generally 1203°C (2200°F) (at the supply end of the bath) to 592°C (1100°F) (at the exit end of the bath). The float glass ribbon is taken out of the tin bath and annealed in an annealing furnace, that is, controlled cooling, and then cut into glass sheets having the desired length and width. The temperature of the float glass ribbon between the tin bath and the annealing furnace is generally 480Ό (896°F)-580°C (1076°F) and the temperature of the float glass ribbon in the annealing furnace is generally 204Ό (400°F) -557°C (1035° F) (peak). U.S. Patent Nos. 4, 466, 562 and

4,671, 155 (herein incorporated by reference) provide a discussion of float glass processes.

[0083] CVD and spray pyrolysis methods are preferred over MSVD methods in float glass processes because they are more compatible with coating continuous substrates, such as float glass ribbons, at elevated temperatures. Exemplary CVD and spray pyrolysis coating methods are described in U.S. Patent Nos. 4,344,986; 4,393,095; 4,400,412; 4,719,126; 4,853,257; and 4,971 , 843, is hereby incorporated by reference into the present invention.

[0084] In the present invention, one or more CVD coating devices can be used at several points in the float glass ribbon manufacturing process. For example, the CVD coating device can be used when the float glass ribbon passes through the tin bath, after it leaves the tin bath, before it enters the annealing furnace, when it passes through the annealing furnace, or after it leaves the annealing furnace. Because the CVD method can coat float glass ribbons that are still subject to movement in the harsh environment associated with the manufacture of float glass ribbons, the CVD method is particularly suitable for providing a PM coating 24 on float glass ribbons in a molten tin bath. US Patent Nos. 4, 853, 257; 4, 971, 843; 5, 536, 718; 5, 464, 657; 5,714, 199; and 5, 599, 387 (herein incorporated by reference into the present invention) describe The CVD coating device and method for coating float glass ribbon in a molten tin bath can be used in the present invention.

[0085] For example, as shown in FIG. 2, one or more CVD applicators 50 may be located in a tin bath 52 above a molten tin bath 54. As the float glass ribbon 56 moves through the tin bath 52, the evaporated precursor composition (ie, the photoactive coating precursor material (1), such as the metal oxide precursor material, and the light absorption band changing material (2) For example, organometallic precursor materials) can be added to the carrier gas and on the top surface 21 of the guide belt 56. The precursor composition decomposes to form the PM coating 24 of the present invention. The material (2) can be at least partially soluble in the coating precursor material (1) under the required deposition conditions, such as completely soluble in the coating precursor material (1). Any required amount of material (2) to achieve the required movement of the light absorption band into the visible region can be added, mixed in, or dissolved in the coating precursor material (1). Alternatively, two separate precursors can be evaporated separately and combined.

[0086] Exemplary coating precursor materials (1) (eg, titanium dioxide precursor materials) that can be used in the present invention to form the titanium dioxide PM coating 24 by the CVD method include, but are not limited to, titanium oxide, low oxygen Compound, or super-oxide. In one embodiment, the precursor material (1) may include one or more titanium alkoxides, such as, but not limited to, titanium methoxide, titanium ethoxide, titanium propoxide, titanium butoxide, and the like; or isomers thereof , Such as titanium isopropoxide, titanium tetraethoxide, and the like. Exemplary precursor materials suitable for the present invention include, but are not limited to, titanium tetraisopropoxide (Ti(0C₃H₇）₄) (Hereinafter ΤΊΊΡ) and titanium tetraethoxide (Ti(0C₂H₅）₄) (Hereinafter "TTEt"). Alternatively, the titanium dioxide precursor material (1) may be titanium tetrachloride.

[0087] The light absorption band moving material (2) can be any material that moves or widens the light absorption band of the resulting coating to at least partially expand into, or further expand to the visible region (400nm-800nm) of the electromagnetic spectrum. The material can include one or more kinds of Luo (Cr), machine (V), manganese (Mn), copper (Cu), iron (Fe), magnesium (Mg), gun (Sc), armor (Y), ingot (Nb), Aluminum (Mo), Nail (Ru), Duck (W), Silver (Ag), Lead (Pb), Nickel (Ni), Baht (Re), and/or any mixture or combination thereof. For example, the precursor material (2) may be a metal oxide or alkoxide. In one embodiment, the material (2) is at least partially soluble, eg, most of the precursor material (1) is soluble. Exemplary carrier gases that can be used in the CVD method of the present invention include, but are not limited to, air, nitrogen, oxygen, ammonia, and mixtures thereof. The concentration of the precursor composition in the carrier gas can vary with the specific precursor composition used. However, for a coating having a thickness of about 200 angstroms, it is expected that the concentration of the precursor composition in the carrier gas is usually 0.01% by volume to 0.1% by volume, for example, 0.01% by volume to 0.06% by volume For example, 0.015 volume% -0.06 volume %; for example, 0.019 volume% -0.054 volume %. For thicker coatings, the precursor composition can be higher.

[0088] For the CVD method (and the spray pyrolysis method discussed below), the temperature during which the substrate 22 (such as float glass ribbon 56) forms the PM coating 24 thereon should be such that the metal-containing precursor is combined The substance decomposes and forms a coating with a desired amount of photoactivity, such as photocatalytic activity, photoactive hydrophilicity, or both. The lower limit of this temperature range is greatly affected by the decomposition temperature of the selected precursor composition. For the above-mentioned titanium-containing precursors, sufficient precursor combinations are provided

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The lower limit of the temperature of the substrate 22 where the substance decomposes is generally in the range of 400°C (752°F) to 500°C (932°F). The upper limit of this temperature range is affected by the method of coating the coated substrate. For example, if the substrate 22 is a float glass ribbon 56 and the PM coating 24 is applied to the float glass ribbon 56 in the molten tin bath 50 during the manufacture of the float glass ribbon 56, the float glass ribbon 56 can reach more than 1000°C (1832° F) temperature. The float glass ribbon 56 can be thinned or changed in size (such as stretched or compressed) when the temperature exceeds 800°C (1472°F). If the PM coating 24 is applied to the float glass ribbon 56 before or during thinning, the PM coating 24 may crack or shrink accordingly when the float glass ribbon 56 is stretched or compressed. Therefore, the PM coating 24 can be applied when the float glass ribbon 56 is dimensionally stable (except for thermal shrinkage during cooling), for example, below 800°C (1472° F) (for soda lime glass), and makes the float glass Belt 56 is at a temperature that decomposes metal-containing precursors, for example, over 400°C (752°F) ο

[0089] For spray pyrolysis, US Patent Nos. 4,719,126; 4,719,127; 4,111,150; and

3, 660, 061 (herein incorporated by reference) describes spray pyrolysis devices and methods that can be used in conventional float glass ribbon manufacturing processes. Although the spray pyrolysis method is very suitable for coating moving float glass ribbons like the CVD method, the spray pyrolysis has more complicated equipment than the CVD equipment and is usually used between the outlet end of the tin bath and the inlet end of the annealing furnace.

[0090] Exemplary metal-containing precursor compositions that can be used in the present invention to form PM coatings by spray pyrolysis methods include relatively water-insoluble organometallic reactants, especially metal acetylacetonates, which are spray-milled or wet. It is ground to a particle size below 10 microns and suspended in an aqueous medium by using a chemical wetting agent. A suitable metal acetylacetonate precursor material for forming a PM coating containing titanium dioxide is titanyl acetylacetonate (TiO (C5H7O2)₂) ο For example, the light absorption band changing material as described above can be mixed with or dissolved in the acetylacetonate precursor material. In one embodiment, the relative concentration of the metal acetylacetonate and the moving precursor material in the aqueous suspension is 5-40% by weight of the aqueous suspension. The wetting agent can be any relatively low foaming surfactant, including anionic, nonionic or cationic compositions. In one embodiment, the surfactant is non-ionic. The amount of wetting agent added is usually 0.24% by weight, but may be 0.01% to 1% or more. The aqueous medium can be distilled water or deionized water. Aqueous suspensions for pyrolytic deposition of metal-containing films are described in US Patent No. 4,719,127, especially column 2, line 16 to column 4, line 48, which is incorporated herein by reference.

[0091] Those skilled in the art can understand that the bottom surface 60 of the float glass ribbon placed directly on the molten tin (usually referred to as the "tin side") has tin diffused in the surface, and the tin provided on the tin side The absorption pattern is different from the opposite surface 21 which is not in contact with the molten tin (commonly referred to as "air side"). The PM coating of the present invention can be formed on the air side of the float glass ribbon by the CVD method as described above while it is carried on the tin, and after it leaves the tin bath, it can be formed on the float glass by the CVD or spray pyrolysis method. The air side of the ribbon is formed, and/or is formed on the tin side of the float glass ribbon by a CVD method after it leaves the tin bath.

[0092] As an alternative to introducing oxygen in the atmosphere of the tin bath to form an oxide coating, the precursor composition may itself include one or more organic oxygen sources. The organic oxygen can be, for example, an ester or a carboxylate, such as an alkyl ester in which the alkyl group has a B-hydrogen. Suitable esters may have C2-Ci. Alkyl esters of alkyl groups. Exemplary esters that can be used in the present invention are described in WO 00/75087, which is incorporated herein by reference.

[0093] For MSVD, US Patent Nos. 4, 379, 040; 4, 861, 669; 4, 900, 633; 4, 920, 006;

4, 93& 857; 5, 32& 768; and 5, 492, 750 (herein incorporated by reference in the present invention) describe the MSVD device for sputtering metal oxide films onto substrates (including glass substrates) And method. MSVDI art is generally not suitable for providing PM coating on the float glass ribbon during the manufacturing process, because among other reasons, the MSVD process needs to reduce pressure during the sputtering operation, so it is difficult to form a reduction on the continuously moving float glass ribbon. Pressure. But the MSVD method can be used to deposit PM coating 24

Onto a substrate 22, such as a glass sheet. The substrate 22 can be heated to a temperature of 400°C (752°F) to 500°C (932°F), so that the MSVD sputter coating on the substrate crystallizes during the deposition process, which eliminates subsequent heating operations. Heating the substrate during the sputtering process is generally not a preferred method because the additional heating operation during the sputtering process can reduce throughput. Alternatively, the sputtered coating can be directly crystallized in the MSVD coating device without post-heat treatment by using high-energy plasma, but also due to its tendency to reduce the throughput of the MSVD coater, this is not a preferred method.

[0094] An exemplary method of using the MSVD method to provide a PM coating (especially a PM coating of 300 Angstroms or less and having an RMS surface roughness of 2 nm or less) is to sputter a dopant-containing coating onto On the substrate, the coated substrate is removed from the MSVD coater, and then the coated substrate is heat-treated to crystallize the sputtered coating. For example, but not limiting the present invention, doped with at least one selected from the group consisting of Lo (Cr), Organic (V), Manganese (Mn), Copper (Cu), Iron (Fe), Magnesium (Mg), Bronze (Sc) , Armor (Y), armor (Nb), Aluminum (Mo), nail (Ru), pigeon (W), silver (Ag), lead (Pb), nickel (Ni), baht (Re), and/or their mixture or combination of light absorption band moving material metal The titanium target can be sputtered in a nitrogen/oxygen atmosphere with 5-50% oxygen, such as 20% oxygen, at a pressure of 5-10 millimeters, so that doped titanium dioxide with a desired thickness is sputtered and deposited on the substrate 22 coating. The deposited coating did not crystallize. The coated substrate is taken out of the applicator and heated to a temperature of 400°C (752°F)-600°C (1112°F) for a sufficient time to promote the formation of a crystalline form of titanium dioxide to generate photoactivity. In one embodiment, the substrate is heated at a temperature of 400°C (752°F) to 600°C (1112°F) for at least 1 hour. If the substrate 22 is a glass sheet cut from a float glass ribbon, the PM coating 24 may be sputter deposited on the air side and/or the tin side.

[0095] The substrate 22 with the PM coating 24 deposited by CVD, spray pyrolysis, or MSVD methods may subsequently be subjected to one or more post-coating annealing operations. It can be understood that the annealing time and temperature can be affected by several factors, including the composition of the substrate 22, the composition of the PM coating 24, the thickness of the PM coating 24, and whether the PM coating 24 is in direct contact with the substrate 22 or not. Whether it is one layer of the multilayer laminate on the substrate 22.

[0096] Regardless of whether the PM coating 24 is provided by a CVD process, a spray pyrolysis process, or an MSVD process, the substrate 22 includes sodium ions that can migrate from the substrate 22 to the PM coating 24 deposited on the substrate 22. Ions can inhibit or destroy the photoactivity of the PE coating 24, such as photocatalytic activity and/or photoactivity, by forming inert compounds while consuming titanium, for example, by forming sodium titanate or by causing light-excited charge recombination. Hydrophilicity. Therefore, a sodium ion diffusion barrier (SIDB) layer may be deposited on the substrate before the PM coating 24 is deposited. Suitable SIDB layers are discussed in detail in US Patent No. 6,027,766, which is incorporated herein by reference. By post-coating heating, a sodium barrier layer can be used for sodium-containing substrates, such as soda lime glass. For the application of the PM coating 24 of the present invention in a molten metal bath, a sodium barrier layer is optional.

[0097] The SIDB layer may include, but is not limited to, various diamond oxides, boron oxides and iron oxides, tin oxide, silicon oxide, titanium oxide, aluminum oxide, fluorine-doped tin oxide, aluminum oxide, magnesium oxide, zinc oxide, and The mixture of amorphous or crystalline metal oxides is formed. Mixtures include, but are not limited to, magnesium/lu oxide and zinc/tin oxide. Those skilled in the art can understand that metal oxides may include metal oxides, super-oxides or suboxides. Although the thickness of the SIDB layer required to prevent the sodium ion poisoning of the PM coating varies with several factors, including the time the substrate is held at a temperature higher than the temperature at which sodium ion migration occurs, the rate of sodium ion migration from the substrate, The rate of sodium ion migration through the SIDB layer, the thickness of the PM coating, and the degree of photocatalytic activity required for most occasions in a given occasion, the thickness of the SIDB layer should be at least about 100 angstroms, such as at least about 250 angstroms, such as, At least about 500 angstroms thick to prevent sodium ion poisoning of the PM coating. The SIDB layer can be deposited on the substrate 22 by any conventional method, such as but not limited to CVD, spray pyrolysis, or MSVD method. If a spray pyrolysis or CVD method is used, the substrate 22 can be maintained at a temperature of at least about 400°C (752°F) to ensure that the metal-containing precursor decomposes to form the SIDB layer. The SIDB layer can be formed by other methods including a sol-gel method, and the sol-gel method as described above is generally not suitable for the manufacture of glass float tape.

[0098] The tin oxide SIDB layer, such as fluorine-doped tin oxide SIDB, can be deposited on the substrate by spray pyrolysis, including the formation of dibutyltin difluoride (C₄H₉)₂SnF₂And an aqueous suspension of water and apply the aqueous suspension to the substrate by spray pyrolysis. Generally speaking, aqueous suspensions usually contain 100-400 grams of dibutyltin difluoride per liter of water. Wetting agents can be used as suspension enhancers. In the process of preparing the aqueous suspension, the dibutyltin difluoride particles can be ground to an average particle size of 1-10 microns. The aqueous suspension can be stirred vigorously to provide a uniform distribution of particles in the suspension. The aqueous suspension is delivered by spray pyrolysis to the surface of the substrate at a temperature of at least about 400 Ό (752° F), such as about 500 Ό-700 Ό (932° F-1292° F), so that the aqueous suspension is formed by pyrolysis Tin oxide SIDB layer. It can be understood that the thickness of the SIDB layer formed by this process can be controlled by the coating line speed, the concentration of dibutyltin difluoride in the aqueous suspension and the spray rate, and other parameters.

[0099] Alternatively, the tin oxide SIDB layer may be formed on the substrate by a CVD method in an air carrier gas mixed with water vapor in a metal-containing precursor such as monobutyltin trichloride vapor (hereinafter "MBTTCL). MBTTCL vapor may be present in the air carrier gas applied to the substrate at a concentration of at least about 0.5%, while the substrate is at a temperature sufficient to deposit the tin-containing layer, such as at least about 400 Ό (952° F), such as about 500 Ό -800 Ό (932° F-1472° F) to form a tin oxide SIDB layer. It can be understood that the thickness of the SIDB layer formed by this process can be controlled by the coating linear velocity, the concentration of MBTTCL vapor in the air carrier gas, the carrier gas flow rate, and other parameters.

[0100] The SIDB layer formed by the MSVD process is described in US Patent Application Serial No. 08/597, 543 (filed on February 1, 1996, entitled Alkali Metal Diffusion Barrier Layer (alkali metal diffusion barrier layer), which is hereby incorporated by reference Incorporated in the present invention), which discloses the formation of an alkali metal diffusion barrier layer. The barrier layer disclosed therein is generally effective at a thickness of about 20 angstroms to about 180 angstroms, and the effectiveness increases as the density of the barrier layer increases.

[0101] The PM coating 24 of the present invention may be photoactive when exposed to radiation in the ultraviolet range of the electromagnetic spectrum, such as 300nm-400nm, and/or the visible range (400nm-800nm), such as photocatalysis and/or Photoactive hydrophilic. Ultraviolet radiation sources include natural sources, such as solar radiation, and artificial sources such as black light or ultraviolet light sources such as UVA-340 light source available from Q-Panal Company (Cleverand, Ohio).

[0102] As shown in FIG. 1, in addition to the PM coating 24 of the present invention, one or more functional coatings 46 may be deposited on the substrate 22. For example, the functional coating 46 may be deposited on the major surface 60 of the substrate 22 opposite to the surface 21. The term "functional coating" as used herein refers to a coating that changes one or more of the physical properties of the substrate on which it is deposited, such as optical, thermal, chemical or mechanical properties, and is not intended to be used during subsequent processing. Remove from the substrate. The functional coating 46 may have one or more functional coating films with the same or different compositions or functions. The term "layer" or "film" as used herein refers to a coating area having a desired or selected coating composition. The film can be uniform, non-uniform, or have a gradient composition change. If the outer surface or part (that is, the surface or part furthest from the substrate), the inner surface or part (that is, the surface or part closest to the substrate) and the part between the outer and inner surfaces have substantially the same composition, The film is "uniform". When moving from the inner surface to the outer surface, if the film has one or more components in substantially increasing fractions and one or more other components in substantially decreasing fractions, the film is "graded" and vice versa Of course. If the film is not uniform or gradient, then the film is "non-uniform". The "coating" is composed of one or more "films".

[0103] The functional coating 46 may be a conductive coating, such as, for example, the conductive heating window coating disclosed in US Patent Nos. 5,653, 903 and 5, 02 & 759, or a single film or multiple films that can be used as an antenna coating. Likewise, the functional coating 46 may be a solar control coating, for example, a visible, infrared or ultraviolet energy reflecting or absorbing coating. Examples of suitable solar control coatings are, for example, in U.S. Patent Nos. 4, 89 & 789; 5, 821, 001; 4, 716, 086; 4, 610, 771; 4, 902, 580; 4, 716, 086; 4, 806, 220; 4, 89& 790; 4, 834, 857; 4, 94& 677; 5, 059, 295; and 5, 02& 759, and found in US Patent Application No. 09/05& 440. Similarly, the functional coating 46 may be a low emissivity coating.

Low-emissivity coating "refers to visible wavelength energy, for example, 400nm to about 800nm (eg, to about 780nm) can be transmitted through the coating but reflect longer wavelength solar infrared energy and/or thermal infrared energy and is generally used to enhance Thermal insulation performance of architectural glass windows. "Low emissivity" means that the emissivity is lower than 0.4, such as lower than 0.3, such as lower than 0.2. Examples of low-emissivity coatings are found in, for example, US Patent Nos. 4,952,423 and 4,504,109 and British document GB2,302,102. The functional coating 46 may be a single-layer or multi-layer coating and may contain one or more metals, non-metals, semi-metals, semiconductors, and/or alloys, compounds, composites, combinations, or blends thereof. For example, the functional coating 46 may be a single-layer metal oxide coating, a multi-layer metal oxide coating, a non-metal oxide coating, or a multi-layer coating.

[0104] Examples of functional coatings suitable for use in the present invention may be su NGATE® known SOLARBAN® series coatings (purchased from PPG Industries, Inc. (Pittsburgh, Pennsylvania)). These functional coatings usually include one or more Dielectric or anti-reflective materials, such as anti-reflective coating films of metal oxides or metal alloy oxides, are preferably transparent or substantially transparent to visible light. The functional coating 46 may also include an infrared reflective film containing a reflective metal, such as precious metals such as gold, copper or silver, or a combination or alloy thereof, and may further include a base film or a base film on and/or under the metal reflective layer. Barrier films, such as titanium, are known in the art.

[0105] The functional coating 46 can be deposited in any conventional manner, such as but not limited to magnetron sputtering vapor deposition (MSVD), chemical vapor deposition (CVD), spray pyrolysis (ie, pyrolysis deposition), atmospheric pressure CVD (APCVD), low pressure CVD (LPCVD), plasma enhanced CVD (PEVCD), plasma assisted CVD (PACVD), thermal or electron beam evaporation, cathodic arc deposition, plasma spray deposition, and wet chemical deposition (eg, sol -Gel, silver mirror method, etc.). For example, U.S. Patent Nos. 4, 584, 206, 4, 900, 110, and 5, 714, 199 (herein incorporated by reference in the present invention) disclose a method of depositing a metal-containing film on the bottom surface of a glass ribbon by chemical vapor deposition and Device. This known device can be located downstream of the molten tin bath in the float glass process, so that the functional coating is provided under the glass ribbon, that is, on the side opposite to the PM coating of the present invention. Alternatively, one or more other CVD coaters may be located in the tin bath to deposit the functional coating on or under the PM coating 24 on the float glass ribbon. If the functional coating is applied to the PM coating side of the substrate, the functional coating can be applied in a tin bath before the PM coating. If the functional coating is on the side 60 opposite to the PM coating, the functional coating can be applied to the tin side of the substrate 22 after the tin bath in the float process as described above, for example, by CVD or MSVD. In another embodiment, the PM coating 24 can be deposited on all or a portion of the surface 60 and the functional coating 46 can be deposited on all or a portion of the surface 21 ±o

[0106] An exemplary article of the present invention is given in the form of an insulating glass (IG) unit 30 in FIG. 3. The insulating glass unit has a first pane 32 that is isolated from a second pane 34 by an isolation component (not shown) and fixed in place by a sealant system, forming a cavity between the two panes 32, 34. The first pane 32 has a first surface 36 (No 1 surface) and a second surface 38 (No 2 surface). The second pane 34 has a first surface 40 (No 3 surface) and a second surface 42 (No 4 surface). The first surface 36 may be the outer surface of the IG unit, that is, the surface exposed to the environment, and the second surface 42 can be the inner surface, that is, the surface that forms the interior of the structure. Examples of IG units are disclosed in US Patent Nos. 4, 193, 236; 4, 464, 874; 5, 08 & 258; and 5, 106, 663, which are incorporated herein by reference. In one embodiment shown in Figure 3, the PM coating 24 may be located on the 1 or 4 surface, such as on the 1 surface. The PM coating 24 reduces fogging and makes the IG unit 30 easier to clean and maintain. In this embodiment, one or more optional functional coatings 46 as described above can be deposited on at least a portion of the N2 2, No 3, or Nίί 4 surface.

[0107] The advantages of the present invention relative to the ion implantation and sol-gel method for forming a self-cleaning coating include the method of forming a thin, dense, PM film on the substrate, which is different from the ion implantation and sol-gel coating method. The result is generally thicker, porous self-cleaning coatings. Another advantage is that the method for providing a PM coating according to the present invention avoids the need to apply a coating or coating

The need to reheat the substrate after the layer precursor is used in conventional ion implantation and sol-gel methods. This not only makes the method cheaper and more effective, such as lower equipment cost, lower energy cost, and lower production time, but also significantly reduces the possibility of sodium ion migration and therefore the effect of the present invention on the PM coating 24 The sodium ions are poisoned. In addition, the method of the present invention is easily applicable to forming a PM coating on a continuously moving substrate, such as a glass float belt.

[0108] Those skilled in the art can understand that the present invention can be improved without departing from the basic principles disclosed in the above description. Therefore, the specific embodiments described in detail herein are only illustrative and do not limit the scope of the present invention, while the latter is entirely given by the appended claims and any and all equivalents thereof.

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