Process for depositing layers

Abstract

The present disclosure provides a method of making a coated glass article, the method including the steps of providing a glass substrate having a surface; providing an aqueous solution of dimethyltin dichloride (DMT); vaporizing the aqueous solution of dimethyltin dichloride to form a gaseous mixture including dimethyltin dichloride and water; delivering the gaseous mixture to the surface of the glass substrate; and depositing a tin oxide-based layer on the surface of the glass substrate, wherein the temperature of the surface of the glass substrate is at least 550°C when the gaseous mixture is delivered to the surface of the glass substrate.

Description

[Technical Field]

[0001] The present invention relates to a process for depositing a layer on the surface of a substrate. [Background technology]

[0002] Coatings on substrate surfaces are used in many fields. Some of the more useful coatings include metal oxides, such as tin oxide. Some metal oxides, including doped tin oxide, can form transparent conductive oxide (TCO) coatings.

[0003] Methods for depositing metal oxide coatings include physical vapor deposition methods such as sputtering, or liquid-based methods such as sol-gel using spin-coating or dip-coating techniques. One particularly useful method for depositing coatings is chemical vapor deposition (CVD), in which fluid precursors in vapor form are delivered to the surface of the substrate, where the precursors react and / or decompose to deposit the coating. Various subsets of CVD include metal-organic (MO)CVD, combustion (C)CVD, plasma-enhanced (PE)CVD, and aerosol-assisted (AA)CVD.

[0004] The key to a successful CVD process is the selection of precursors. For tin oxide coatings, many metal precursors have been investigated. Dimethyltin dichloride (DMT) has been widely used as a precursor for the deposition of tin oxide coatings for over 30 years. For example, in U.S. Pat. No. 5,090,985, DMT was heated to a liquid state, mixed with nitrogen to vaporize it, mixed with oxygen and water vapor, and directed onto the surface of a hot glass substrate being manufactured using the float glass process.

[0005] DMT is generally supplied as a solid material, requiring specialized containers that make it difficult to transport and store. It would be beneficial to increase the versatility of DMT's use as a precursor to tin oxide coatings, and therefore its transport and storage methods.

[0006] According to a first aspect of the present invention, there is provided a method of producing a coated glass article, comprising the steps of: providing a glass substrate having a surface; providing an aqueous solution of dimethyltin dichloride (DMT); vaporizing an aqueous solution of dimethyltin dichloride to form a gaseous mixture comprising dimethyltin dichloride and water; delivering a gaseous mixture to a surface of a glass substrate; depositing a tin oxide based layer on the surface of the glass substrate; When the gaseous mixture is delivered to the surface of the glass substrate, the temperature of the surface of the glass substrate is at least 550°C. A method for producing a coated glass article is provided.

[0007] Surprisingly, we found that aqueous solutions of DMT can be used directly to deposit tin oxide onto glass substrates at the temperatures described above, providing a useful alternative to the conventional method of vaporizing DMT and then combining it with water vapor.

[0008] In the context of the present invention, when a layer is said to be "based" on one or more particular materials, this means that the layer consists primarily of the corresponding one or more materials, and typically means that the layer comprises at least about 50 atomic % of the one or more materials.

[0009] In the following description of the invention, unless otherwise indicated, the disclosure of alternative values ​​at the upper or lower limits of an acceptable range for a parameter and the indication that one of those values ​​is preferred over the other is to be construed as implicitly indicating that each intermediate value of that parameter between the more preferred and less preferred alternative values ​​is itself preferable to the less preferred value and each intermediate value between the less preferred value and the intermediate value.

[0010] Throughout this specification, the terms "comprising" or "comprises" mean including the specified components but do not exclude the presence of other components. The terms "consisting essentially of" or "consisting essentially of" mean including the specified components but excluding materials present as impurities, unavoidable materials present as a result of the process used to provide the components, and components other than components added for purposes other than achieving the technical effect of the invention. Generally, when referring to a composition, a composition consisting essentially of a set of components will contain less than 5% by weight, typically less than 3% by weight, and more typically less than 1% by weight of unspecified components.

[0011] The terms "consisting of" or "consisting of" mean the inclusion of the specified elements, but the exclusion of other elements.

[0012] Wherever appropriate and depending on the context, the use of the words "comprise" or "comprising" can also be interpreted to mean "consist essentially of" or "consist essentially of" and can also be interpreted to mean "consist of" or "consisting of."

[0013] References herein such as "in the range of x to y" are intended to include the interpretation "from x to y," and therefore include values ​​x and y.

[0014] For the purposes of this invention, a transparent material or transparent substrate is a material or substrate that is capable of transmitting visible light so that objects or images on the other side or behind the material can be clearly seen through the material or substrate.

[0015] In the context of the present invention, the "thickness" of a layer is represented, for any location on the surface of the layer, by the distance through the layer from that location on the surface of the layer to a location on the opposite surface of the layer in the direction of the smallest dimension of the layer.

[0016] In the context of this invention, a "derivative" is a chemical substance that is structurally related to, and theoretically derivable from, another chemical substance.

[0017] When the gaseous mixture is delivered to the surface of the glass substrate, the temperature of the surface of the glass substrate is at least 570° C., preferably at least 580° C., more preferably at least 590° C., and most preferably at least 600° C., but preferably at most 800° C., more preferably at most 750° C., even more preferably at most 730° C., and most preferably at most 720° C. In some preferred embodiments, when the gaseous mixture is delivered to the surface of the glass substrate, the temperature of the surface of the glass substrate is at least 580° C., but at most 750° C. Depositing a layer when the substrate is at these preferred temperatures can improve the crystallinity of the layer and improve toughness (resistance to heat treatment).

[0018] Preferably, the coated glass article exhibits a sheet resistance of at most 50 Ω / sq, at most 40 Ω / sq, more preferably at most 30 Ω / sq, and most preferably at most 25 Ω / sq, but preferably at least 1 Ω / sq, more preferably at least 3 Ω / sq, and even more preferably at least 5 Ω / sq. In alternative embodiments, the coated glass article may exhibit a sheet resistance of 40 to 350 Ω / sq, preferably 40 to 325 Ω / sq, and the coated glass article may exhibit a sheet resistance of 1000 to 3000 Ω / sq. The sheet resistance of the coated glass article is measured on the surface of the glass substrate on which the tin oxide-based layer is deposited. The sheet resistance of the coated glass article may be measured using a four-point probe method and a commercially available four-point probe.

[0019] Preferably, the gaseous mixture also includes molecular oxygen and / or a carrier gas. More preferably, the gaseous mixture also includes molecular oxygen and a carrier gas. The molecular oxygen may be provided as part of a gaseous composition such as air or in a substantially purified form. Preferably, the carrier gas includes nitrogen, argon, and / or helium. Regardless of the specific components, since the gaseous mixture is comprised of multiple gases, it is preferred to premix the gases so that the gaseous mixture is substantially homogeneous prior to depositing the tin oxide-based layer.

[0020] Preferably, the aqueous solution of dimethyltin dichloride has a concentration of at least 30 wt%, more preferably at least 40 wt%, even more preferably at least 45 wt%, but preferably at most 70 wt%, more preferably at most 60 wt%, even more preferably at most 55 wt%.

[0021] Preferably, the gaseous mixture has a molar percentage of DMT of at least 0.5 mol%, more preferably at least 1 mol%, even more preferably at least 1.5 mol%, but preferably at most 10 mol%, more preferably at most 7 mol%, even more preferably at most 5 mol%.

[0022] Preferably, the gaseous mixture has a molar percentage of water of at least 15 mol%, more preferably at least 25 mol%, even more preferably at least 30 mol%, but preferably at most 60 mol%, more preferably at most 50 mol%, even more preferably at most 40 mol%. In some preferred embodiments, the gaseous mixture further comprises separately added water in addition to the water formed by vaporizing the aqueous solution of DMT.

[0023] Preferably, the gaseous mixture has a molar percentage of oxygen of at least 15 mol%, more preferably at least 25 mol%, even more preferably at least 30 mol%, but preferably at most 50 mol%, more preferably at most 40 mol%, even more preferably at most 35 mol%.

[0024] Preferably, the surface of the glass substrate is the main surface of the glass substrate. Preferably, the glass substrate is transparent. The glass substrate can be a transparent metal oxide-based glass plate. Preferably, the glass plate is a clear float glass plate, preferably a low-iron float glass plate. By clear float glass is meant glass having a composition defined in BS EN 572-1 and BS EN 572-2 (2004). For clear float glass, the Fe2O3 level is typically 0.11% by weight. Float glass with an Fe2O3 content of less than about 0.05% by weight is typically referred to as low-iron float glass. Such glasses typically have the same basic composition with respect to other oxide components. That is, low-iron float glass, like clear float glass, is also a soda-lime silicate glass. Typically, low-iron float glass has less than 0.02% by weight of Fe2O3. The glass plate can be a borosilicate-based glass plate, an alkali aluminosilicate-based glass plate, or an aluminum oxide-based crystal glass plate.

[0025] Preferably, forming the gaseous mixture comprises heating an aqueous solution of dimethyltin dichloride and / or further precursor compounds. Preferably, the heating uses a bubbler system or a thin film evaporator system. Thin film evaporator systems are particularly suitable for production scale processes.

[0026] Preferably, the aqueous solution of dimethyltin dichloride is heated to a temperature of at least 160°C, more preferably at least 170°C, even more preferably at least 175°C, but preferably at most 240°C, more preferably at most 220°C, even more preferably at most 210°C.

[0027] Preferably, the gaseous mixture reaches a vapour pressure of at least 0.01 Bar, more preferably at least 0.03 Bar, even more preferably at least 0.04 Bar, and most preferably at least 0.05 Bar.

[0028] Preferably, the process is carried out using chemical vapor deposition (CVD). CVD may be carried out in conjunction with the manufacture of the substrate, preferably a transparent glass substrate. In one embodiment, the glass substrate may be formed utilizing the well-known float glass manufacturing process. Preferably, the process is carried out during the float glass manufacturing process. In this embodiment, the glass substrate is also referred to as a glass ribbon. Conveniently, CVD may be carried out in either a float bath, a furnace, or a furnace gap. A preferred method of CVD is atmospheric pressure CVD (e.g., online CVD carried out during the float glass process). However, it should be understood that a CVD process may be used separately from the float glass manufacturing process or well after the formation and cutting of the glass ribbon.

[0029] As noted above, CVD is preferably carried out at near atmospheric pressure during the float glass manufacturing process. Alternatively, CVD can be carried out using low-pressure CVD or ultra-high vacuum CVD. CVD can be carried out using aerosol-assisted CVD or direct liquid injection CVD. Furthermore, CVD can be carried out using microwave plasma-assisted CVD, plasma-enhanced CVD, remote plasma-enhanced CVD, atomic layer CVD, combustion CVD (flame pyrolysis), hot-wire CVD, metalorganic CVD, rapid thermal CVD, vapor phase epitaxy, or photoinitiated CVD. After deposition of the CVD layers, the glass substrate is typically cut into sheets for storage or convenient transportation.

[0030] In certain embodiments, CVD is a dynamic deposition process. Thus, in these embodiments, the glass substrate is moving when a tin oxide-based layer is formed thereon or thereover. Preferably, the glass substrate moves at a predetermined speed, for example, greater than 1.78 m / min (70 in / min), more preferably greater than 2.5 m / min (98.4 in / min), as the tin oxide-based layer is deposited. In one embodiment, the glass substrate moves at a speed between 3.175 m / min (125 in / min) and 16.7 m / min (657 in / min), preferably between 3.175 m / min (125 in / min) and 15.24 m / min (600 in / min), as the tin oxide-based layer is deposited.

[0031] When the process is performed during a float glass manufacturing process, a float glass apparatus may be provided, preferably including a canal section through which molten glass is delivered from a melting furnace to a float bath section where the process forms a continuous glass ribbon. The glass ribbon may advance from the bath section through an adjacent annealing furnace and cooling section. The continuous glass ribbon may serve as a substrate upon which the tin oxide-based layer is deposited.

[0032] The bath section may include a bottom section within which a bath of molten tin is contained, a roof, an opposing sidewall, and an end wall. It should be understood that the bath may include other suitable materials to achieve desired results. The roof, sidewall, and end wall may together define an enclosure in which a non-oxidizing atmosphere is maintained to prevent oxidation of the molten tin. Additionally, a coating apparatus including a gas distribution beam may be disposed in the bath section. The gas distribution beam in the bath section may be used to apply a tin oxide-based layer by the subject process described herein, or to apply an additional coating onto the substrate before or after applying the tin oxide-based layer.

[0033] During operation, the molten glass can flow downward along the canal below the adjusting pins at a controlled rate onto the surface of the tin bath. On the tin bath, the molten glass spreads laterally under gravity, surface tension, and certain mechanical influences, advancing through the bath to form a ribbon. The ribbon is removed on a lift-out roll and preferably then transported through the annealing furnace and cooling section on aligned rolls. A heater may be provided in the annealing furnace to gradually reduce the temperature of the glass ribbon according to a predetermined regime as it is transported. Ambient air may also be directed toward the glass ribbon, typically via a fan in the cooling section.

[0034] The subject process described herein can be carried out in the float bath section or further along the production line, for example, the tin oxide-based layer can be deposited in the gap between the float bath section and the annealing furnace, or in the annealing furnace itself.

[0035] To carry out the process in the float bath section, a suitable non-oxidizing atmosphere, generally nitrogen or a nitrogen-predominant mixture of nitrogen and hydrogen, can be maintained to prevent oxidation of the molten tin. The atmospheric gas can be introduced through a conduit operably connected to the distribution manifold. The non-oxidizing atmospheric gas can be introduced at a rate sufficient to maintain a slight positive pressure, on the order of about 0.001 to about 0.01 atmospheres above ambient atmospheric pressure, to compensate for normal losses and prevent ingress of external atmosphere. For purposes of the subject matter described herein, the above pressure range is considered to constitute normal atmospheric pressure. Heat to maintain the desired temperature regime within the tin bath and enclosure can be provided by radiant heaters within the enclosure and the glass ribbon itself.

[0036] The atmosphere in the furnace is typically atmospheric. However, if desired, an inert atmosphere may be maintained in the furnace section. Similarly, the atmosphere in the gap between the furnace and the bath is typically atmospheric and the atmosphere of the bath section, although an inert atmosphere may also be provided. In either case, the pressure of the inert atmosphere may be substantially similar to the pressure of the atmosphere in the bath section.

[0037] To deposit tin oxide-based layers on glass ribbon substrates, the gas distribution beam may be positioned in the bath section, in the gap between the bath section and the annealing furnace, or within the annealing furnace. The gas distribution beam is one form of reactor that may be used in carrying out the subject processes described herein.

[0038] A suitable distribution beam configuration for delivering precursor material in accordance with the subject matter described herein is an inverted, generally channel-like framework formed by spaced apart inner and outer walls defining two enclosed cavities through which a suitable heat exchange medium can be circulated to maintain the distribution beam at a desired temperature.

[0039] Preferably, the gaseous mixture is delivered to the coating apparatus. In certain embodiments, the gaseous mixture is supplied to the coating apparatus and exhausted from the coating apparatus using one or more gas distribution beams prior to the deposition of the tin oxide-based layer. Preferably, the gaseous mixture is formed before being supplied to the coating apparatus. For example, an aqueous solution of dimethyltin dichloride can be vaporized and delivered to a supply line connected to the inlet of the coating apparatus. A carrier gas, such as molecular oxygen and / or nitrogen, can be delivered to the supply line and mixed with the DMT and water. In other embodiments, the gaseous mixture can be formed within the coating apparatus.

[0040] The gaseous mixture may be supplied through a supply conduit. Depending on the location of deposition, the supply conduit may be surrounded by a cooling fluid. The supply conduit may extend along the distribution beam, and the gaseous mixture may be introduced through drop lines spaced along the supply conduit. The supply conduit may lead to a delivery chamber in a header supported by a framework. The gaseous mixture introduced through the drop lines exits the delivery chamber through a passage toward a coating chamber defining a vapor space opening above the glass substrate, where the gaseous mixture may flow along the surface of the substrate.

[0041] Baffle plates may be provided within the delivery chamber to uniformly distribute the gaseous mixture across the distribution beam and ensure that the gaseous mixture is emitted to the glass substrate in a smooth, laminar, uniform flow across the distribution beam. Spent gas may be collected and removed through exhaust chambers along the sides of the distribution beam.

[0042] Various configurations of distribution beams used in chemical vapor deposition are suitable for the method of the present invention and are known in the art. In one such alternative distribution beam configuration, the gaseous mixture is introduced through a gas supply duct where it is cooled by a cooling fluid circulating through a plurality of ducts. The gas supply duct may lead to a glass flow restrictor through an elongated opening.

[0043] The gas flow restrictor may comprise a plurality of metal strips vertically mounted in abutting relationship to one another, longitudinally crimped in a sinusoidal pattern and extending along the length of the distributor. Adjacent crimped metal strips may be arranged "out of phase" to define a plurality of vertical channels therebetween. These vertical channels have a small cross-sectional area compared to the cross-sectional area of ​​the gas supply duct, allowing the gaseous mixture to be discharged from the gas flow restrictor at a substantially constant pressure along the length of the distributor.

[0044] The gaseous mixture can be discharged from the gas flow restrictor into an inlet side of a substantially U-shaped guide channel, which generally includes an inlet section of the coating chamber that opens onto the glass substrate and at least one exhaust section, and the used precursor gas can be removed from the glass. It should be understood that the guide channel can have any suitable size, shape, and configuration, as desired. The rounded corners of the blocks defining the coating channel promote a uniform, laminar flow of the coating parallel to the glass substrate surface.

[0045] Preferably, the tin oxide based layer is deposited on the surface of the glass substrate at a deposition rate of at least 2 nm per second, more preferably at least 5 nm per second, even more preferably at least 7 nm per second.

[0046] Preferably, the tin oxide based layer comprises tin(IV) oxide, more preferably consists essentially of tin(IV) oxide, and even more preferably consists of tin(IV) oxide.

[0047] In some preferred embodiments, the tin oxide-based layer may include doped tin oxide and / or mixed oxide. The doped tin oxide may be doped with one or more of fluorine, indium, antimony, boron, manganese, zinc, aluminum, chromium, phosphorus, strontium, or cadmium. Preferably, the doped tin oxide is doped with one or more of fluorine, indium, or antimony. More preferably, the doped tin oxide is doped with fluorine. In this case, the gas mixture preferably also contains HF and / or trifluoroacetic acid. Doping the tin oxide-based layer may make the layer conductive.

[0048] When doped, the tin oxide based layer preferably contains at least 0.2 atomic % dopant, more preferably at least 0.4 atomic % dopant, even more preferably at least 0.6 atomic % dopant, and most preferably at least 0.8 atomic % dopant, but preferably at most 5 atomic % dopant, more preferably at most 2 atomic % dopant, even more preferably at most 1.5 atomic % dopant, and most preferably at most 1.2 atomic % dopant. These preferred ranges can be advantageous for solar cell applications in terms of optimizing cell efficiency.

[0049] The tin oxide-based layer can be deposited directly on the surface of the glass substrate. Alternatively, the tin oxide-based layer can be indirectly deposited on the surface of the glass substrate. That is, the tin oxide-based layer can be deposited on one or more previously deposited layers. For example, the tin oxide-based layer can be deposited on a silica-based layer, preferably in direct contact with the silica-based layer. In some preferred embodiments, the tin oxide-based layer is deposited on and in direct contact with a silica-based layer, where the silica-based layer is deposited on and in direct contact with a further tin oxide-based layer.

[0050] When this process is performed during the float glass manufacturing process, preferably, the surface of the glass substrate in question is the gas-side surface. Coating glass manufacturers typically prefer to deposit coatings on the gas-side surface (rather than the tin-side surface of the float glass) because deposition on the gas-side surface can improve the properties of the coating.

[0051] The coated glass article may also exhibit low haze values. As described herein, the term "haze" refers to the percentage of incident visible light that is scattered as it passes through the coated glass article. As described herein, the haze exhibited by the coated glass article is measured from the surface of the glass substrate on which the tin oxide-based layer is deposited. In one embodiment, the coated glass article may exhibit a haze of 0.5% or less. Preferably, the coated glass article exhibits a haze of 0.4% or less. In some embodiments, the coated glass article exhibits a haze between 0.1 and 0.4%. The haze exhibited by the coated glass article may be measured using a commercially available haze meter, such as the BYK-Gardner haze-gard plus.

[0052] Any invention described herein may be combined with any feature of any other invention described herein, mutatis mutandis.

[0053] It will be understood that additional features applicable to one aspect of the present invention may be used in any combination and in any number, and may also be used with any of the other aspects of the present invention in any combination and in any number, including, but not limited to, any dependent claim of any claim used as a dependent claim of any other claim in the claims of this application.

[0054] The reader is directed to all articles and documents related to this application that have been filed contemporaneously or previously hereto and are published herewith, the contents of all such articles and documents being incorporated herein by reference.

[0055] All features disclosed in this specification (including any accompanying claims, abstract, and drawings), and / or all steps of any disclosed method or process, may be combined in any combination, except combinations in which at least some of the features and / or steps are mutually exclusive.

[0056] Each feature disclosed in this specification (including the accompanying claims, abstract, and drawings), unless expressly stated otherwise, may be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.

[0057] The present invention will be further described by the following specific embodiments, given by way of example and not limitation, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0058] [Figure 1] 1 is a cross-sectional schematic view of a glass article coated in accordance with certain embodiments of the present invention. [Figure 2] FIG. 1 is a schematic diagram of a cross section of a glass article coated in accordance with certain embodiments of the present invention. [Figure 3] FIG. 1 is a schematic diagram of a vertical cross section of an installation for carrying out a float glass process incorporating multiple CVD apparatus for producing coated glass articles according to certain embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0059] 1 shows a cross-section of a coated glass article 1 according to one particular embodiment of the present invention. The coated glass article 1 comprises a transparent float glass substrate 2 that has been coated with a tin oxide-based layer 3 using CVD.

[0060] 2 shows a cross-section of a coated glass article 1 according to one particular embodiment of the present invention. The coated glass article 1 comprises a transparent float glass substrate 2 that is coated, in sequence, with a silica-based layer 4 and a tin oxide-based layer 3 using CVD.

[0061] As noted above, the process of the present invention may be carried out using CVD in conjunction with the manufacture of glass substrates in a float glass process, which is typically carried out using a float glass facility such as facility 10 shown in Figure 3. However, it should be understood that the float glass facility 10 described herein is merely exemplary of such a facility.

[0062] As shown in FIG. 3 , a float glass facility 10 includes a canal section 20 through which molten glass 19 is delivered from a melting furnace to a float bath section 11, where a glass substrate is formed. In this embodiment, the glass substrate is referred to as a glass ribbon 8. However, it should be understood that the glass substrate is not limited to a glass ribbon. From the bath section 11, the glass ribbon 8 proceeds through an adjacent annealing furnace 12 and a cooling section 13. The float bath section 11 includes a bottom section 14 containing a bath of molten tin 15, a roof 16, opposing sidewalls (not shown), and end walls 17. The roof 16, sidewalls, and end walls 17 together define an enclosure 18 within which a non-oxidizing atmosphere is maintained to prevent oxidation of the molten tin 15.

[0063] During operation, molten glass 19 flows along canal 20 under regulating tweezers 21 and flows downward at a controlled rate toward the surface of tin bath 15. At the surface of the molten tin, molten glass 19 spreads laterally due to the effects of gravity, surface tension, and certain mechanical influences, and advances across tin bath 15 to form glass ribbon 8. Glass ribbon 8 is removed from bath section 11 via lift-out rolls 22 and then transported on aligned rolls through annealing furnace 12 and cooling section 13. Deposition of the coating preferably occurs in float bath section 11, although it may also be possible to deposit it further along the glass production line, for example, in gap 28 between float bath 11 and annealing furnace 12, or within annealing furnace 12.

[0064] As shown in FIG. 3, four CVD apparatuses 9, 9A, 9B, and 9C are shown within the float bath section 11. Therefore, depending on the frequency and thickness of the coating layers required, it may be desirable to use some or all of the CVD apparatuses 9, 9A, 9B, and 9C. One or more additional coating apparatuses (not shown) may be provided. Alternatively or additionally, one or more CVD apparatuses may be located in the annealing furnace gap 28. Any by-products are removed through the coater extraction slot and then removed from the contamination control plant. For example, in one embodiment, a silica layer is formed using CVD apparatus 9A, and a fluorine-doped tin oxide layer is formed using CVD apparatus 9.

[0065] A suitable non-oxidizing atmosphere, generally nitrogen or a mixture of nitrogen and hydrogen with nitrogen as the primary component, is maintained in the float bath section 11 to prevent oxidation of the molten tin 15 comprising the float bath. Atmospheric gas is introduced through conduit 23 operably connected to distribution manifold 24. The non-oxidizing gas is introduced at a rate sufficient to compensate for normal losses and maintain a slight positive pressure, on the order of about 0.001 to about 0.01 atmospheres above ambient atmospheric pressure, to prevent the ingress of external atmosphere. For purposes of this description, the above pressure range will be considered to constitute normal atmospheric pressure.

[0066] Generally, CVD is formed at substantially atmospheric pressure. Therefore, the pressure in the float bath section 11, the annealing furnace 12, and / or the gap 28 between the float bath 11 and the annealing furnace 12 may be substantially atmospheric. Heat to maintain the desired temperature conditions in the float bath section 11 and the enclosure 18 is provided by a radiant heater 25 within the enclosure 18. Because the cooling section 13 is not sealed, the atmosphere within the furnace 12 is typically atmospheric, and the glass ribbon 8 is open to the surrounding atmosphere. The glass ribbon 8 is then allowed to cool to ambient temperature. To cool the glass ribbon 8, ambient air may be directed at the glass ribbon 8 by a fan 26 in the cooling section 13, for example. A heater (not shown) may also be provided within the annealing furnace 12 to gradually reduce the temperature of the glass ribbon 8 according to predetermined conditions as the glass ribbon 8 passes therethrough. [Example]

[0067] The chemical components aqueous DMT (50% wt / wt, Galata), nitrogen (compressed liquid, Air Products), oxygen (PT# Ox ED300, over-dried, AirGas) were used as received without further purification.

[0068] Aqueous DMT was used directly as a precursor for atmospheric pressure chemical vapor deposition of SnO thin films onto SiO-coated low-iron soda-lime float glass plates (2.8 mm x 20.3 cm x 61.0 cm, "substrate") using an online mini-dynamic coater. The substrate was attached to an electronically controlled ceramic conveyor "boat" that moved between the coating furnace components. First, the substrate was stopped in the preheating section until it reached 620 °C, then moved to the main furnace, which was maintained at the same temperature. Once inside the main furnace, the substrate either moved at a line speed of 190.5 cm / min (preferably 63.5 to 889 cm / min, more preferably 190.5 to 508 cm / min) or remained stationary for 15 or 20 seconds while the gaseous mixture was ejected from the 15.2 cm precursor nozzle, depositing dynamic or static coatings, respectively. In the examples herein, dynamic coatings were prepared. The coated glass articles were transferred from the main furnace to the annealing section where they remained until they cooled to the set temperature (400°C), after which they exited the main furnace and were cooled by a fan.

[0069] The gaseous mixture was prepared as follows: Nitrogen carrier gas was plumbed into a stainless steel (316 steel) pressure pot used to contain and deliver aqueous dimethyltin dichloride. A sapphire rotameter was used to meter aqueous dimethyltin dichloride into a tube evaporator set at 350°F (176.7°C). Additional nitrogen gas flowed through the evaporator barrel, carrying the dimethyltin dichloride and water vapor to the coater head via a heated line (200-220°C) and a four-way connector in a 200°C oven. Oxygen gas was mixed with the DMT, water, and nitrogen vapor just before the four-way connector. After each deposition, water from the metering pressure pot was used to purge the system.

[0070] Examples were prepared using five different sets of conditions, varying the percentage of DMT and water in the gaseous mixture, as shown in Table 1 below. Each example was prepared on three different occasions, and average thickness and efficiency measurements were determined. Table 1 shows the percentage of each component in the gaseous mixture, with the remainder being nitrogen. Table 1 also shows the flow rate of each component, the average thickness of the deposited tin oxide layer, and the average deposition efficiency. The deposition efficiency is essentially the percentage of moles of DMT in the gaseous mixture that actually deposit as tin oxide on the substrate per minute. The coating area is determined by the width of the glass and its line speed.

[0071] [Table 1]

[0072] Table 1 - Deposition conditions and resulting coating thickness and deposition efficiency for some examples according to the invention

[0073] The results shown in Table 1 indicate that the thickness of the tin oxide layer increases with increasing proportions of DMT and water in the gas mixture, and all examples show reasonable deposition efficiencies.

[0074] The invention is not limited to the details of the above embodiments, and extends to any novel feature or combination of features disclosed in this specification (including the accompanying claims, abstract and drawings), or any novel feature or combination of steps of any disclosed method or process.

Claims

1. A method for manufacturing a coated glass article, wherein the method is The steps include preparing a glass substrate having a surface, The steps include preparing an aqueous solution of dimethyltin dichloride (DMT), The steps include: vaporizing the aqueous solution of dimethyltin dichloride to form a gaseous mixture containing dimethyltin dichloride and water; The steps include delivering the gaseous mixture to the surface of the glass substrate, The step includes depositing a tin oxide-based layer on the surface of the glass substrate, When the gaseous mixture is delivered to the surface of the glass substrate, the surface temperature of the glass substrate is at least 550°C. A method for manufacturing coated glass articles.

2. The method according to claim 1, wherein when the gaseous mixture is delivered to the surface of the glass substrate, the surface temperature of the glass substrate is at least 570°C, preferably at least 580°C, more preferably at least 590°C, most preferably at least 600°C, and preferably up to 800°C, more preferably up to 750°C, even more preferably up to 730°C, and most preferably up to 720°C.

3. The method according to claim 1 or 2, wherein when the gaseous mixture is delivered to the surface of the glass substrate, the temperature of the surface of the glass substrate is at least 580°C and at most 750°C.

4. The method according to claim 1 or 2, wherein the coated glass article exhibits a sheet resistance of up to 50 Ω / sq, preferably up to 40 Ω / sq, more preferably up to 30 Ω / sq, most preferably up to 25 Ω / sq, and preferably at least 1 Ω / sq, more preferably at least 3 Ω / sq, and even more preferably at least 5 Ω / sq.

5. The method according to claim 1 or 2, wherein the gaseous mixture also includes molecular oxygen and / or a carrier gas.

6. The method according to claim 1 or 2, wherein the concentration of the aqueous solution of dimethyltin dichloride is at least 30 wt%, preferably at least 40 wt%, more preferably at least 45 wt%, and preferably up to 70 wt%, more preferably up to 60 wt%, and even more preferably up to 55 wt%.

7. The method according to claim 1 or 2, wherein the gaseous mixture has a molar percentage of DMT of at least 0.5 mol%, preferably at least 1 mol%, more preferably at least 1.5 mol%, and preferably up to 10 mol%, more preferably up to 7 mol%, and even more preferably up to 5 mol%.

8. The method according to claim 1 or 2, wherein the gaseous mixture has a molar percentage of water of at least 15 mol%, preferably at least 25 mol%, more preferably at least 30 mol%, and preferably up to 60 mol%, more preferably up to 50 mol%, and even more preferably up to 40 mol%.

9. The method according to claim 1 or 2, wherein the gaseous mixture contains at least 15 mol%, preferably at least 25 mol%, more preferably at least 30 mol%, and preferably up to 50 mol%, more preferably up to 40 mol%, and even more preferably up to 35 mol% of oxygen in molar percentage.

10. The method according to claim 1 or 2, wherein the formation of the gaseous mixture comprises heating an aqueous solution of dimethyltin dichloride and / or further precursor compounds, preferably using a bubbler system or a thin-film evaporator system for the heating.

11. The method according to claim 10, wherein the aqueous solution of dimethyltin dichloride is heated to a temperature of at least 160°C, preferably at least 170°C, more preferably at least 175°C, and preferably up to 240°C, more preferably up to 220°C, and even more preferably up to 210°C.

12. The method according to claim 1 or 2, wherein the method is carried out using chemical vapor deposition (CVD).

13. The method according to claim 1 or 2, performed during a float glass manufacturing process.

14. The method according to claim 1 or 2, wherein the tin oxide-based layer comprises doped tin oxide and / or mixed oxides.

15. The method according to claim 14, wherein the doped tin oxide is doped with one or more of fluorine, indium, antimony, boron, manganese, zinc, aluminum, chromium, phosphorus, strontium, or cadmium, preferably fluorine.

16. The method according to claim 1 or 2, wherein the tin oxide-based layer is deposited directly on the surface of the glass substrate.

17. The method according to claim 1 or 2, wherein the tin oxide-based layer is indirectly deposited on the surface of the glass substrate, and the tin oxide-based layer is deposited on a silica-based layer, preferably in contact with the silica-based layer.

18. The method according to claim 17, wherein the silica-based layer is deposited on and in direct contact with a further tin oxide-based layer.

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