MXPA01001605A - Compositions, apparatus and methods for forming coatings of selected color on a substrate and articles produced thereby - Google Patents

Abstract

A copper containing component and a manganese containing component are applied onto the surface of a substrate to form a coating having a selected ratio of copper to manganese to form a desired color. Further, color shifting of a multi-component coating upon subsequent heat treatment is minimized or prevented by determining the most mobile species in the coating and then placing a concentration gradient layer of an oxide of that mobile species between the substrate and the coating. Upon subsequent heat treatment, the mobile species in the gradient layer diffuses into the substrate more readily than the mobile species in the coating. Still further, color shifting due to heating, e.g. tempering operations, is minimized by adding calcium to an FeOx system to prevent darkening of the film after heating. An apparatus for forming a graduated coating on a substrate includes o coating station positioned along a conveyor. The coating station includes a first coating dispenser pivotally mounted on a first support and at least one exhaust hood. The first coating dispenser is positioned such that an axis through the delivery end of the first coating dispenser subtends the substrate at a predetermined angle.

Description

COMPOSITIONS, APPARATUS AND METHODS FOR FORMING COLORED COATINGS SELECTED ON A SUBSTRATE AND ARTICLES PRODUCED WITH THEMSELVES CROSS REFERENCE TO RELATED REQUESTS This application is a partial continuation of U.S. Patent Application Serial No. 08 / 992,484 filed December 18, 1997, and entitled "Methods and apparatus for depositing pyrolytic coatings having an attenuation zone on a substrate and articles produced with them ". This application also claims the benefits of U.S. Provisional Application serial number 60 / 096,415, filed August 13, 1998, and entitled "Methods and apparatus for forming a graded attenuation zone on a substrate and articles produced with the same" . The descriptions of the above applications are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the invention The invention relates in general to compositions, apparatus and methods for forming coatings of selected color on a substrate and more in particular to vary the components in aqueous suspensions of organometallic compositions and to deposit the suspensions on a glass substrate to pyrolytically produce a stable coating film of color or selected colors on the glass substrate. In one embodiment of the invention, the coating has a graded attenuation zone on the surface of the substrate, for example, a floating glass ribbon. 2. Description of the technology currently available In various industrial applications, it is desirable to form a coating on glass surfaces. For example, automobile windshields have coated areas called "tone bands" or "dimming zones". In many passenger vehicles, the rear and rear seat windows are coated with a uniform thickness coating. Said coated areas reduce the transmittance of visible, infrared or ultraviolet light to reduce glare, visibility of vehicle content and / or decrease the transmittance of solar energy to reduce the heat gain in the interior of the vehicle. The term "attenuation zone" generally refers to a band adjacent to the edge of the transparent moon, for example, the upper edge of the windshield of an automobile in which the visibility through the transparent moon changes from one zone to another. less transparent to another more transparent. In U.S. Patent No. 3,660,061, organometallic salts are dissolved in an organic solution and sprayed onto a hot glass surface to form a metal oxide film. In U.S. Patent No. 4,719,127, the disclosure of which is incorporated by reference, aqueous suspensions of organometallic salts are sprayed onto a hot glass surface to pyrolytically form metal oxide coatings on the surface. The coating technology currently available is used to form gray or dark gray coatings, particularly in the automotive industry, so that coated glass can be used with the largest number of car body colors without "out of tune" with color of the car body. In addition, many of the known coated substrates change color or tone with subsequent heating during tempering and the configuration of the coated substrate. Said heat induced color change hinders the production of coated materials of consistent color stability. In addition, many of the known coated substrates are not chemically durable, for example, when contacted with solutions having citric acid. U.S. Patent No. 2,676,114 discloses the use of a plurality of stationary shields arranged geometrically with respect to a plurality of evaporative coating sources to form a series of discrete coating bands., adjacent, of different thicknesses on the substrate. One limitation of the technique is that the discrete coating bands give the coated substrate an aesthetically unpleasant appearance of bands or fringes. U.S. Patent No. 3,004,875 discloses a plurality of spray guns located on top of a shield for applying a graduated coating to the edge of a substrate. The resulting band has a thicker zone located away from the spray guns and a thinner zone next to the spray guns. The limitations of this technology are that the device requires a complex assembly of spray protection and that the resulting band has a mottled appearance due to the transients that develop under the protector near the edge of the protector during the coating operation. U.S. Patent No. 4,138,284 to Postu-pack discloses applying a dye composition along an edge of a glass substrate. The resulting web has a relatively wider area of substantially uniform thickness with a narrow, graduated boundary portion between the coated and uncoated portions of the substrate. As can be appreciated, it would be advantageous to provide compositions, methods and apparatus for applying selected color-transmitted coating (s) on the surface of a substrate that reduce or eliminate the limitations associated with currently known compositions and methods. COMPENDIUM OF THE INVENTION This invention relates to a method for forming a coating, for example, a coating containing copper and manganese, of a desired color on a substrate, for example, a glass substrate, applying a copper-containing component and a component containing manganese on the substrate in a selected ratio to form the coating having the selected copper to manganese ratio. More particularly, when the ratio of the component having copper and the component containing manganese is one, the coating is blue in transmission. When the ratio of the copper containing component and the manganese containing component is less than about one, the color varies from blue gray or amber in transmission as the ratio decreases. When the ratio of the copper containing component and the manganese containing component is greater than about one, the color varies from blue gray to brown in transmission as the ratio increases. The invention also relates to compositions for forming coatings of a selected color on a substratum. Coatings containing copper and manganese can be used to form coatings ranging from amber to blue to light brown depending on the copper to manganese ratio. A chromium, copper and manganese system provides a neutral gray coating in transmittance. Cobalt can be added to said copper and manganese system to increase the chemical durability, for example, the durability to the citric acid of the coating. An iron oxide system provides a golden colored coating in transmittance. Copper can be added to said iron oxide system to obtain a light gray brown coating in transmittance. Chromium can be added to the copper-iron oxide system to obtain a darker gray-brown coating in transmission. A coating of manganic oxide (Mn203) provides a mauve / lilac coating, while a film with a phase (Mn ++) (Mn +++) 2 04 provides a light amber film. (Mn ++) (Mn +++) 2 04 will be called "Mn304". The invention also relates to a method of preventing the change of color of a substrate coated with multiple components or multiple layers to subsequent heat treatment, which includes the steps of determining the most mobile species in a layer of the coating and placing a layer of gradient of concentration of an oxide of said mobile species between the substrate, for example, a sheet of glass, and the coating. The concentration gradient layer is preferably applied directly on the glass substrate, but it can also be applied on a coating layer formed on the glass substrate. Upon further treatment with heat, the mobile species of the concentration gradient layer diffuses to the substrate more easily than the mobile species in the coating, which minimizes the depletion of the mobile species of the coating and reduces or eliminates the increase in transmittance. This invention also relates to an apparatus for forming a graduated coating on a surface of a substrate, for example, a piece of glass. The apparatus includes a coating station and facilitates the movement of the piece of glass relative to one another. The coating station includes a coating dispenser mounted, preferably pivotably, on a first support. An exhaust hood is mounted on one or both sides of the coating dispenser. A source of coating material and a source of pressurized fluid are in flow communication with the coating dispenser. The coating dispenser is mounted in relation to the movement facilities of the glass in such a way that an imaginary axis through the dispensing orifice, for example, the nozzle or centerline of the expected coating spray if more than one nozzle is used of the coating dispenser intersects the glass movement facilities at a predetermined angle, such that the coating spray dispensing at the dispensing end of the coating dispenser provides a graduated coating on the glass surface. The graduated coating is thicker near the dispensing end of the coating dispenser and finer farther away from the dispensing end of the coating dispenser. Preferably, the thickness of the coating has a uniform decrease as the distance from the dispensing end of the coating dispenser or the edge of the glass part near the coating dispenser increases. The apparatus may include a second coating dispenser pivotally mounted on a second support. One or both coating dispensers can be movable vertically and horizontally. In another embodiment of the invention, the apparatus includes a plurality of spaced coating dispensers or nozzles placed in alignment or displaced from one another on the surface of the substrate to be coated. Each coating dispenser dispenses a cone or fan-shaped spray, for example, an elliptical configuration, of coating material onto a surface portion of the substrate. The area covered by a nozzle overlaps an area covered by another nozzle to form a coating having a central region of substantially uniform thickness with graded regions located on each side of the central region. The invention also relates to a method of forming an attenuation zone on a surface of the substrate by placing a coating dispenser adjacent to one side of the substrate and tilting the coating dispenser to the opposite side of the substrate in such a way that the coating material dispensed by the coating dispenser is deposited on the substrate as a graduated attenuation zone. Preferably, when practicing the invention, an organometallic material is used which pyrolytically forms a coating. Furthermore, the invention relates to a manufactured article, for example, an architectural window or a transparent car window, made using the above methods and apparatus. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an isometric view of a coating station that performs the characteristics of the invention. Figure 2 is an isometric view of an alternative embodiment of the coating station of the invention. Figure 3 is a block diagram of a floating glass making apparatus having a coating station of the invention. Figure 4 is a sectional side view of a substrate coated with the coating station of the invention to form a graded attenuation zone. Figure 5 is a bottom view of a CVD coater incorporating the ideas of the invention. Figure 6 is a perspective view of a further embodiment of the coating apparatus of the invention. Figure 7 is a plan view of a coating configuration formed by the apparatus shown in Figure 6; Figure 8 is a sectional end view of a substrate coated with the coating apparatus of Figure 6; Figures 9 and 10 are graphs of the percentage reflectance and transmittance across coated glass pieces produced with the coating apparatus of Figure 6. And Figure 11 is an isometric view of a vehicle with windows formed by coated glass substrates. according to the invention. Figure 12 is a plan view of Samples Al to Al4 of Table I. DESCRIPTION OF THE PREFERRED EMBODIMENTS For the purposes of the following description, the terms "near", "far", "superior", "inferior", "right", "left", "vertical", "horizontal", "superior", "inferior", "above", "below" and its derivatives will refer to the invention as described in the following specification. It is to be understood that the invention may assume various alternative variations and sequences of steps, except when expressly specified otherwise. It is also to be understood that the specific methods, compositions, devices and articles described in the following specification are merely exemplary embodiments of the invention. Therefore, the specific dimensions and other physical characteristics related to the embodiments described herein are not to be considered as limiting the invention. When forming a tone band or attenuation zone on a substrate, it may be desirable to form the attenuation zone of a selected transmitted color. This can be particularly important for car windows, so that the color of the windows of the car is aesthetically pleasing to the color of the car. In this regard, embodiments of the invention include coating compositions and methods that can be used to form a coating of a selected color or transmitted colors on a glass substrate. Said compositions and methods can be used with conventional coating devices, such as, but not limited to, conventional chemical vapor deposition (CVD), PVD, MSVD or pyrolytic coating devices. Examples of such conventional coating devices are described in U.S. Patent Nos. 2,676,114, 3,004,875 and 4,138,284, the disclosures of which are incorporated herein by reference. With reference to Figure 1, a coating apparatus 10 incorporating characteristics of the invention is shown. The coating apparatus 10 includes a coating station 14 for depositing a graduated coating on a substrate. In Figures 1 and 2, the graduated coating of the invention is represented with spaced lines of decreasing thickness. However, it is to be understood that this representation is purely symbolic and in fact the coating of the invention has a graduated appearance, not in stripes. In the explanation of the invention, although without limitation thereof, a pyrolytic coating is deposited on a heated substrate. Therefore, in the following explanation, a hot chamber is used, for example, an oven 12, and a conveyor 16 with the coating station 14. The conveyor belt 16 extends from the oven 12 through the storage station. coating 14 and is configured to transport a substrate 18, e.g., a piece of flat glass to be coated, from the furnace 12 through the coating station 14 at a selected speed. The conveyor belt 16 can be of any conventional type, such as a plurality of rotating metal or ceramic rolls. As can be seen, the furnace 12 can be a flat glass formation chamber of the type known in the art, where the molten glass can be placed on a metal bath and formed to obtain a flat glass ribbon. The conveyor belt 12 may be the conveyor belt that moves the glass ribbon from the forming chamber to an annealing furnace of the type used in the art to anneal the flat glass ribbon. The coating station 14 includes a coating dispenser 20, such as a conventional Binks-Sames Model 95 air atomizing spray nozzle. The coating dispenser 20 is configured to spray an atomized liquid material in a fan or cone shaped configuration. to a surface of the substrate 18 in the coating station 14. The coating dispenser 20 is in flow communication with a source 22 of coating material., preferably an aqueous suspension of one or more metal acetylacetonates or other conventional coating materials, by a flexible conduit 24. Suitable coating materials are described, for example, in U.S. Pat. 4. 719,127 to Greenberg, the disclosure of which is incorporated herein by reference. A dosing pump 26, such as a conventional Cole-Parmer MasterFlex 07523-20 pump, is in flow communication with the conduit 24. The coating dispenser 20 is also in flow communication with a source 28 of compressed fluid, such as air, by a flexible conduit 30. The coating dispenser 20 is preferably mounted for pivotal, lateral and vertical movement in a conventional manner on a support 34, such as a metal frame. Preferably, the coating dispenser 20 is mounted in relation to the piece of glass to be coated or the supporting surface of the conveyor belt 16 in such a way that it forms a; angle a (represented only in FIG. 1) between about 0-90 °, preferably between about 20-40 °, between an imaginary axis or line L drawn through the center of the spray coming out of the nozzle or discharge end of the coating dispenser 20 and a vertical axis V extending substantially perpendicular to the support surface or the surface of the substrate 18 being coated. The coating dispenser 20 can also be moved vertically and horizontally in such a way that the height of the coating dispenser 20 above the conveyor belt 16 as well as the position of the dispenser 20 along the conveyor belt 16 and the lateral position of the dispenser of coating 20 with respect to the conveyor belt 16 can be selectively fixed. Although only one coating dispenser 20 is shown in FIG. 1, a plurality of such coating devices 20 may be located on the first support 34, for example, on the side, above or below the first coating dispenser 20. first exhaust hood 40 is located upstream of the coating dispenser 20 with respect to the direction of advancement of the conveyor belt 16 as indicated by the arrowhead line designated with the number 41, and a second exhaust hood 42 is located towards Downstream of the coating dispenser 20 with respect to the advancing direction of the conveyor belt 16. Optionally and preferably, a temperature sensor 43, such as a conventional infrared thermometer, can be placed over the conveyer belt 16 together to the first exhaust hood 40 for detecting the temperature of the substrate 18 for pyrolytic coating. Each exhauster hood 40 and 42 is in flow communication with a respective exhaust duct 44 or 45. An auxiliary exhaust hood 49 can be positioned near the far side of the substrate 18 away from the coating dispenser 20 to provide the capacity of additional exhaustion. In order to avoid excessive undesired spraying on the glass surface, a barrier 51 shown in FIG. 2 can be provided and / or the hood 49 can be used. In this way, the spray of the coating dispenser 20 is not contacted, thus preventing the interference with spraying while preventing the coating material randomly transported through the air from being transported and deposited on the portion of the glass immediately from the coating dispenser 20. With continued reference to FIG. coating apparatus 100 incorporating features of the invention. The coating apparatus 100 includes a second coating station 114 having a second coating dispenser 120 pivotally mounted on a second support 134. A third exhaust hood 47 is located downstream of the second exhaust hood 42. Although not shown in figure 2, an auxiliary exhaust hood 49, shown in figure 1, can also be placed in the first and second covering stations 14 and 114, respectively. The support according to 134 is laterally spaced from the first support 34 so that the second coating dispenser 120 is located between the second and third exhaust hoods 42 and 47. As shown in dashed lines in FIG. placing additional coating dispensers 121 in the second coating station 114, for example, to the side, above or below the second coating dispenser 120. Both in the apparatus 10 and 100, there is no protector or baffle between the spray coming from the coating dispensers and the object that is coated. The second coating dispenser 120 may be in flow communication with the source 28 of compressed fluid and the source 22 of coating material of the first coating dispenser 20 for spraying the same coating material on the substrate 18. Alternatively, as shown in Figure 2, the second coating dispenser 120 may be in flow communication with a separate source 128 of compressed fluid by a conduit 130 and a separate source 122 of coating material by a conduit 124 having a pump metering unit 126 for spraying the same or a different coating on the substrate 18. The additional coating dispenser 121 may also be in flow communication with the same sources or with different sources of compressed fluid and coating material as the coating and dispensing dispensers 20. 120. Figure 3 shows a conventional floating glass system 46 that em features of the invention. As will be readily understood by those skilled in the art of floating glass manufacturing, a conventional floating glass system 46 includes an oven 48 in which molten glass is formed. The molten glass is then transferred to a bath of molten metal contained in a forming chamber 50 to form a glass ribbon on the surface of the metal bath. The glass ribbon leaves the chamber 50 and enters an annealing furnace 52 by means of a conveyor belt 54. As shown in Figure 3, a coating station, for example, the coating station 14 of Figure 1 or the tandem coating station 100 of Figure 2 can be positioned between the chamber 50 and the annealing furnace 52. The operation of the coating station 14 will be described below with special reference to the embodiment shown in Figure 1 In the following explanation, the heating chamber or oven 12 of Figure 1 can be considered the chamber 50 of Figure 3 for a continuous piece of glass, for example, a glass ribbon, or as a conventional oven for Separate pieces of glass. A continuous substrate, for example, a glass ribbon, or discrete substrates 18 to be coated, such as pieces of flat glass, is heated to a desired temperature in the chamber 50 or the oven 12, respectively. The conveyor belt 16 transports the heated substrates 18 to the coating station 14. The coating dispenser 20 is selectively co-located at a desired height and lateral position, i.e. the distance from the side of the conveyor 16, and a angle such that when the substrate 18 is conveyed through the coating station 14, the coating dispenser 20 directs the coating material to the upper surface of the substrate 18. This positioning of the coating dispenser 20 can be accomplished from manually or automatically by a conventional automatic positioning device attached to the coating dispenser 20. As the substrate 18 passes the coating station 14, coating material is moved from the source of coating material 22 to the coating dispenser 20. and mixed with compressed air from the source of compressed fluid 28 exiting the nozzle of the coating dispenser 20 in the form of a spray pattern in the form of a cone of coating material directed towards the hot substrate 18. The first and second exhaust hoods 40 and 42 eject the overcoating material of the coating station 14 to provide a uniform coating essentially free of defects or imperfections. The auxiliary exhaust hood 49 can also be used to further improve the exhaust of the coating station 14. As explained above, to prevent the coating particles present in the air from moving and depositing on the portion of the tape beyond the coating dispenser, a barrier 51 depicted in FIG. 2 can be employed. When the substrate 18 passes through the coating station 14, the coating dispenser 20 sprays the coating material on top of the hot substrate 18, where the coating material pyrolyzes to form a substantially durable graduated pyrolytic coating. The size of the spray fan measured on the surface of the glass, the speed of the conveyor belt 16 and the distance between the nozzle of the coating dispenser 20 and the substrate 18 are fixed in such a way that the spray pattern forms a distribution or desired coating graduation on top of the substrate 18. The volumes and coating pressures through the coating dispenser 20 are selectively controlled to deposit a desired coating gradient and thickness on the surface of the substrate 18. Since the coating dispenser 20 is inclined to the far side of substrate 18, a thicker layer of coating material is deposited on the proximal side of substrate 18, i.e., the side of the substrate closest to coating dispenser 20, and the thickness of the coating material deposited on the substrate 18 decreases as the distance of the edge op decreases. of the substrate (the edge furthest from the coating dispenser), a substantially continuous thickness gradient occurring therebetween, i.e., as the distance of the coating dispenser 20 increases, the coating thickness decreases. Thus, a smooth, graduated coating material of substantially continuous shape 60 is applied across the desired width of the upper surface of the substrate 18. Since protectors or deflectors common in the prior art are not required to carry out the invention. , the resulting coating forms a smooth continuous gradient on the substrate 62 without the limitations of fringes or mottling common in the prior art coating devices. Furthermore, by employing a pyrolytic coating material rather than the colorants common in the prior art, the coated substrate resulting from the invention can be used directly, for example, as a transparent car window, without the need for additional protective measures, such as the protective coatings or the lamination that is generally required for substrates coated with dye of the prior art. As will be understood by those skilled in the art of coating glass, the parameters of the coating system can affect the resulting coating. For example, with all other factors remaining the same, the faster the substrate 18 moves through the coating station, the thinner the overall thickness of the coating will be. The larger the angle, the thinner the coating will be near the coating dispenser 20 and the thicker the coating will be farther away from the coating dispenser 20. As the distance of the coating dispenser 20 increases above the substrate 18, more fine will be the general coating. The greater the flow rate of the coating material through the coating dispenser 20, the thicker the overall coating will be. Example No. 1 Flat glass parts or substrates (available commercially from PPG Industries, Inc., of Pittsburgh, Pennsylvania, under the registered trademark SOLARBRONZE®) of approximately 4.0 mm (0.157 inch) were coated. thickness, 60.1 cm (24 inches) wide and 76.2 cm (30 inches) long with the coating station of the invention shown in Figure 1. The substrates were washed with a dilute detergent solution, they were rinsed with distilled water and then air dried. The clean glass substrates were heated in an horizontal roller hearth electric furnace at an oven temperature of approximately 621 ° C (1150 ° F). The heated substrates were transported by the conveyor belt from the furnace through the coating station at a linear velocity of approximately 635 cm (250 inches) per minute. The temperature of the substrates entering the coating station was approximately 613-615 ° C (1,135-1,139 ° F), as measured by the infrared thermometer 43 placed on the conveyor belt upstream of the first exhaust hood 40. The coating material used was an aqueous suspension of a mixture of finely ground metal acetylacetonates mixed in water at 16.5% by weight and with a specific gravity of 1.025 measured at 22 ° C (72 ° F). The mixture of metal acetylacetonates consisted of 95% by weight of Co (C5H7? 2) 3, hereinafter referred to as "cobaltic acetylacetonate", and 5% by weight of Fe (C5H702) 3, hereinafter referred to as "ferric acetylacetonate". " The aqueous suspension was placed in a vessel having an impeller-type mixer operating at 352 rpm to maintain the suspension. The liquid suspension was delivered to the pulsing nozzle by a laboratory peristaltic dosing pump (Cole-Parmer MasterFlex 07523-20) at a rate of 85 milliliters per minute. The spray nozzle was a type of conventional air atomization (Binks-Sames model 95) and compressed air was used at a gauge pressure of 3.5 kg / cm2 (50 pounds per square inch). The spray nozzle was placed on one side about 17.8 cm (7 inches) from the near side of the substrate and was placed vertically at about 27.9 cm (11 inches) above the surface of the glass substrate to be coated. The sprayer nozzle was tilted in such a way that a center line of the nozzle intersected the top of the substrate at an angle α of about 25 °. This arrangement produced a graded, bronze colored substantially attenuation zone on the glass substrate. As shown in Figure 2, several coating stations 14, 114 can be placed in series to apply the same or other coating material on the substrate 18 in each coating station 14, 114. For example, it can be It is desirable to create a layered or superposed coating or create a selected color on the substrate or form multiple colors on the same substrate using the compositions and methods described in the co-pending United States patent application entitled "Compositions and methods". to form coatings of selected color on a substrate and articles produced therefrom, which is incorporated herein by reference.

Although the foregoing discussion focused on the practice of the invention with a coating device using conventional air atomizing spray nozzles, the invention is not limited to such coating devices, but can be practiced with other types. of coating devices, for example, coatings for vapor deposition of a coating ("CVD coaters"). As will be understood by those skilled in the CVD coating technique, CVD coaters are usually located on top of a moving substrate. The coating block includes distribution slots through which coating material is discharged and one or more exhaust slots are placed transversely to a direction of movement of the substrate. A lower part 138 of a covering block of the CVD 140 type incorporating the principles of the present invention is shown in Figure 5 and can be located, for example, in the forming chamber 50 of a floating glass system 46 as the shown in dashed lines in FIG. 3. As shown in FIG. 5, the CVD coating block 140 may have at least one tapered cover distribution groove 142, which tapers from a narrower width at one end to the other. further widths at the other end, through which a coating material can be directed in a conventional manner towards the surface of a substrate moving in the direction of the arrow X under the cover block 140. Exhausting 144 are placed on each side of the distribution groove 142. The exhaust grooves 144 may be of uniform width as shown in Figure 5 or may be tapered, for example, similarly to the dispensing groove 142. Alternatively, the dispensing groove 142 may be of uniform width and the exhaust grooves 144 may be tapered. A thicker coating will be applied to the surface of the substrate under the narrower portion of the distribution groove 142 than under the wider portion of the distribution groove 142, a coating thickness graduated therebetween being deposited. Figure 6 shows another embodiment of a coating station 148 of the invention. The coating station 148 has a first exhaust hood 40 spaced apart from a second exhaust hood 42 with a plurality of staggered, spaced coating dispensers 200, for example, conventional air atomizing spray nozzles, positioned therebetween. In the embodiment shown in figure 6, but which is not to be considered as limiting the invention, three of said coating dispensers 200 are shown. The coating dispensers 200 are preferably movably or pivotally mounted on a stationary frame above. of a conveyor belt 16 which is used to transport a substrate 18 to be coated to the coating station 148. Naturally, the coating dispensers 200 could alternatively be mounted on a mobile frame or gantry crane to move the coating dispensers 200 to the substrate 18. The coating dispensers 200 are in flow communication with one or more sources of coating material and / or fluid under pressure. As depicted in Figure 6, the coating dispensers 200 are preferably directed downwardly toward the substrate 18 to form spray patterns, such as elongated or elongated spray patterns 150, on the substrate 18. As shown in Figure 7, each elongated configuration 150 has a main shaft 152 with a center 154 and an outer periphery or edge 156. The coating dispensers 200 are arranged so that the spray pattern from a coating dispenser 200 does not interfere with the configuration of spraying from another coating dispenser 200. For example, the coating dispensers 200 may be arranged in a stepped formation such that all the major axes 152 are substantially parallel and spaced apart. As shown in Figure 7, each coating dispenser 200 forms a coated area 158 on the substrate 18 when the substrate 18 passes through the coating station 148. The coating dispensers 200 are preferably positioned in such a way that the area Coated 158 formed by a coating dispenser 20 does not extend beyond the center 154 of the spray of an adjacent coating dispenser 200. Thus, the coated areas 158 overlap to form a coating as depicted in Figure 8 which it has a central region with substantially uniform thickness 162 with tapered or graded side regions 164 located on each side of the coating. If desired, the coated substrate 18 can be cut into two or more pieces. For example, the substrate 18 can be cut in half along a vertical axis Z shown in FIG. 8 to form two separate coated pieces, each piece having a graduated side region 164, or the piece 18 can be cut in three. parts, the center piece having a uniform coating and the outer parts having the graduated region. Although coating dispensers 200 that form elliptical coating configurations were described in the above-explained embodiment, the invention is not limited to such elliptical coating configurations. The coating configurations can be, for example, in any way, for example, circular, oval, etc. In addition, a plurality of such coating stations 148 may be placed in series to spray identical or different coating materials onto the substrate. Figure 9 shows the percentage reflectance ("Ri") of the coated surface; the percentage reflectance ("R2") of the uncoated surface and the percentage transmittance for a coated glass substrate in a coating station using the principles of the invention. The coating station used was similar to the coating station 148 shown in FIG. 6, but had two coating dispensers 200, a coating dispenser 200 being moved to one side of the other a distance of approximately 12.7 cm (5 inches). ). Flat glass pieces (obtainable commercially from PPG Indus-tries, Inc., of Pittsburgh, Pennsylvania, under the registered trademark SOLEXTRA®) of approximately 4.0 mm (0.157 inch) thickness, 60.1 cm (24 inches) wide and 76.2 cm (30 inches) to 101.6 cm (40 inches) long, were sprayed with an aqueous suspension of a mixture of copper, cobalt and manganese acetylacetonates to deposit pyrolytically a coating on the glass surface. The deposited coating had a maximum thickness of about 400-600 A with tapered regions on each side of the coated glass part. The percentage reflectance Ri and R2 and the percentage transmittance were measured at selected positions through the coated glass from one side or tapered edge of the glass to the other tapered side. The position "0" in the abscissa of figure 9 corresponds to one edge of the coated glass sheet, for example, the left side, indicating the other positions of the abscissa the distance from the edge in which the values of the percentage reflectances Rx and R2 and the transmittance. The coating had higher transmittance regions located on the sides of the substrate, ie, in the tapered regions and a lower transmittance region located near the middle of the substrate 18, i.e., the thicker central region with smoothly graded transmittance zones. In between; while the coating had lower reflectance Ri and R2 on the sides of the substrate and higher reflectance near the middle of the substrate. The Rx values were higher than the R2 values in each measurement. As explained above, the adjacent coating dispensers 200 should be positioned in such a way that the spray pattern 150 of a coating dispenser 200 does not interfere with the spray pattern 150 of another coating dispenser 200. FIG. shows the percent reflectance Rx and R2 and the values of the transmissions for a coating applied in a manner similar to that described above, but with the sprays of each of two adjacent coating dispensers 200 deposited in a normal line to the edge of the glass of such so that adjacent sprays give rise to interference between the two spraying configurations. Interference between the two spray configurations from the coating dispensers 200 formed a coating having a mottled central region of non-uniform thickness. The percentages of reflectance and transmittance were measured using Illuminant C CIÉ standard, light 2 degrees observer. In figure 11, a vehicle 210 is generally shown. The vehicle 210 includes a windshield 212, a rear window 214 and side windows 216, 218 and 220. For the sake of explanation, these will be referred to together simply as "windows". The side windows 216 and 218 are formed from coated glass according to the invention to form a graded attenuation zone 222 that varies gradually from a first substantially transparent region, with thin coating 224 near the bottom, to a second less transparent region, with thicker coating 226 near the top. In the preferred embodiment, the windows are installed in the vehicle 210 with the attenuation zones 222 oriented vertically, as shown with respect to the side windows 216 and 218. However, as depicted with respect to the side window 220, the attenuation zone 222 may be oriented horizontally, if desired. The attenuation zone 222 could also be oriented with the first region 224 at the top of the window, if desired. In addition, as described above with respect to the coating assembly 100, the attenuation zone 222 may be formed so that the first region 224 is of a first color and the second region 226 is of a different second color by applying different color materials. coating during the formation of the attenuation zone 222 in adjacent coating stations. Next, specific coating compositions and methods will be described to achieve coatings of the selected transmitted color. Said compositions and methods are grouped in general according to the color produced to facilitate the explanation. However, the particular groupings should not be considered as limiting the invention. COPPER-MANGANESE OXIDE COATINGS It has been found that coatings, in particular pyrolytically deposited coatings, formed using a suspension containing copper containing components and containing manganese, provide excellent coatings whose transmitted color varies from amber or light brown to bluish-gray to blue, depending on the molar ratio of copper to manganese in the applied suspensions. "Specifically, it has been found that aqueous suspensions containing a mixture of manganese-containing acetylacetonates (for example, Mn (C5H702) 2, hereinafter they are called "manganese acetylacetonates" or Mn (C5H702) 3, also called "manganic acetylacetonate") and copper containing acetylacetonates (for example, Cu (C5H702) 2 / also called "cupric acetylacetonate") produce coatings whose color is transmitted from a light brown with high copper content or an amber color with high manganese content to one color blue when the molar ratio of copper to manganese in the coating is already a bluish-gray color when the molar ratio is slightly higher or lower than 1. The color changes when the molar ratio of copper to manganese increases or decreases, are listed in Table I and are shown in Figure 7, which are explained in more detail below. Coated substrates were formed by hand spraying aqueous suspensions of acetylacetonates containing mixed copper and manganese, such as cupric and manganous acetylacetonates, onto clear floating glass substrates cut into 10.2 cm x 10.2 cm (4 x 4 inches) squares. The substrates were washed with a diluted detergent solution, rinsed with distilled water and then air dried. An aqueous suspension of cupric acetylacetonate Cu (C5H702) 2 and manganese acetylacetonate Mn) C5H702) was produced by a conventional wet milling technique, and the acetylacetonate containing copper and manganese were mixed in the desired proportions with deionized water and a chemical wetting agent to disperse, deaerate and suspend the metallic acetylacetonate particles. The substrates were heated in a conventional upper bench muffle furnace at a temperature sufficient to guarantee pyrolysis of the applied suspensions, for example, approximately 600 ° C, and then sprayed by hand with a Binks model 95 spray gun equipped with gravity feed tank. The band of transmitted and reflected colors of the coated substrates, as a function of the composition, is shown in Table I and the color of the Samples is shown in Figure 7. The reflected and transmitted colors of the coated substrate are exposed in a conventional using the coordinates of standard chromaticity Y, x, and for illuminant A, observer 2 ° established by the Commission Internationale de l'Eclairage (CIÉ). The coated substrates were analyzed using X-ray diffraction. It was found that samples A6 to A8 of Table I contained as a major phase a phase of the cubic spinel type Cu1 / Mn1 / 60 which is generally produced in the band of a molar ratio of 0, 8 to 1.1 Cu / Mn in the coating determined by X-ray fluorescence ("XRF"), see Table I. The Cu-rich coatings of Samples Al and A2 had brown color in transmission, and coatings of color rich in Mn were amber in transmission as in Samples A13 and Al4.

Table I CINE chromaticity coordinates of 5 reflectance and transmittance for CuMn oxide films on clear glass < u e ^ a ra or ft & . 0 • (ti > ft < ? e ft or ro 0 ft (ti ft a > you e e o e o > > > * * * In this example, the substrates were prepared and coated in the following manner. Floating glass substrates four millimeters thick, in 10.2 x 10.2 cm (4 x 4 inches) squares were cleaned, passing the substrates through a diluted detergent solution, rinsing the substrates with distilled water and then air drying the substrates The cleaned glass substrates were sprayed with a 50/50 volume percent solution of two-propanol and distilled water and dried with a cellulose-polyester cloth to remove dirt, unwanted film, fingerprints and / or the waste. Aqueous suspensions of cupric acetylacetonate and magnesium acetylacetonate were obtained by conventional wet milling techniques. Said suspensions of single metal acetylacetonate were mixed to create binary suspensions with molar Cu / Mn ratios of the order of 9.09 to 0.43. The glass substrates were transferred to an upper bench muffle furnace and heated to a temperature of about 600 ° C. The heated substrates were sprayed by hand with a puller gun equipped with a gravity fed tank to apply the aqueous suspension to the substrate. The spray gun used in the experiment included a Binks model 63 PB air cap, a Binks model 63 SS fluid nozzle and a Binks model 663 needle. The atomizing air pressure of the gun was set at 3.5 kg / cm2 ( 50 pounds per square inch). The aqueous suspension was sprayed onto the substrate for approximately 8 seconds at a distance of approximately 25.4 centimeters (10 inches) from the surface of the glass.

As shown in Table II, films with a molar ratio of Cu / Mn higher than or equal to about 15.13 produced substrates coated with a brown color in transmittance. As the molar ratio of Cu / Mn determined by XRF in the film decreased, the transmitted color changed from light brown to gray blue to deep blue to lighter blue for samples numbers B1-B9 of Table II. It was determined by XRF analysis that the deep blue coatings of samples numbers B6-B8 of Table II in transmission contained a greater part of a phase of cubic spinel type Cu? Mn?; 80 and were generally produced in the band of the molar ratio of Cu / Mn from 0.8 to 1.2 in the film, determined by XRF. After deposition, the coated substrates were heated at 650 ° C for about ten minutes. This heating produced a change in the percentage luminous transmittance (? Y) and in the color shown in Table II as? E (FMCII). To facilitate the explanation, the increase in transmittance that occurs after the heat treatment will be referred to as "discoloration". E (FMCII) in Table II is defined as the color difference of the coated substrate before and after heating. E (FMCII) is determined according to the conventional formula established by the CIÉ Colorimetry Committee. It should be noted that the blue spinel phase of Cu? Mn? / 60 can be produced using a suspension of acetylacetonate Cu (II) / Mn (II) as in the samples numbers A6-A8 in Table I The same spinel-type phase is observed for the suspension of Cu (II) / Mn (III) acetylacetonate used in samples B6-B8 of Table II. Although Table I does not disclose the results after the heat treatment of samples numbers A6-A8, it is expected that said samples will discolour in a manner similar to samples numbers B6-B8 of Table II.

Table II Diffusion coupling experiments In a Cu-Mn system, copper is the most mobile species. This determination was formed based on the following experiments. A CuO film was sprayed onto the surface of a first heated quartz substrate. In the following explanation, the substrates were at approximately 600 ° C when coated. An Mn304 film was sprayed onto the surface of a second heated quartz substrate. The two substrates were then coupled face to face with portions of the coated surfaces in contact with each other and the remaining portions of the coated surface separated from one another, ie, the portions of the coated surface were not in contact with each other. The substrates were heated at 650 ° C for 16.2 hours. After separation, a portion of the coated surface of the second substrate in direct contact with the CuO film of the coated surface of the first substrate exhibited a dark blue color observed with the naked eye. It is estimated that this is due to Cu ions migrating from the CuO film to the Mn30 film forming a dark blue coating of Cu? Spinel phase, 4Mn? 604. The corresponding zone of the CuO film was much clearer after heating, indicating depletion of Cu ions. The portion of the Mn304 film in the second substrate not in contact with the CuO film passed, after heating, from amber to a mauve / lilac Mn203 film. In another experiment, a CuO film was deposited on a heated quartz substrate and a film of Mn304 was deposited on a heated glass substrate. The two substrates were then coupled face to face with portions of the coated surfaces in contact with each other and the remaining portions without contact with each other. The substrates were heated at 650 ° C for 30 minutes. After separation, a portion of the coated surface of the second substrate in direct contact with the CuO film of the coated surface of the first substrate exhibited a dark blue color in transmission observed with the naked eye. It is estimated that this is due to copper ions migrating from the copper oxide film (CuO) to the Mn304 film forming a spinel-type phase of Cu? / Mn? 604 dark blue. The corresponding zone of the film on the substrate when it was very clear, which indicates depletion of Cu ions. The remaining areas of the films changed little, indicating that the Cu ions do not readily diffuse to the quartz, but instead diffuse preferentially to the Mn304 film deposited on the glass substrate to form the spinel-like phase of Cu, 4Mn ? / 60 dark blue. This also indicates that the Mn ions do not diffuse preferentially to the glass or that they diffuse much more slowly than the Cu ions. A CuO film was deposited on a heated glass substrate and a film of Mn30 was deposited on a heated quartz substrate. The two substrates were then coupled face to face and heated at 650 ° C for 30 minutes. After separation, the surfaces of the amber-colored Mn304 film in the quartz without contact with the copper oxide film in the glass were converted into a lilac Mn203 film. A small portion of the quartz substrate presented a blue zone, which indicates the presence of the spinel phase of Cu? / 4M? JS04 dark blue. However, most of the Cu diffused to the glass rather than to the Mn304 film deposited on the quartz. Thus, by these experiments it was concluded that Cu ions are the most mobile species in the CuMnOx system and is the main species that should be prevented from spreading to the glass substrate. PREPARING THE DISCOLORATION As explained with respect to Example number 2 above, thin films deposited on glass substrates tend to change color after the subsequent heat treatment, such as tempering or annealing. It is estimated that this is due to the exchange of ions of the mobile species between the coating layer and the glass substrate. It is known to place inert layer (s) between the glass substrate and the coating so that it makes (n) a barrier layer to help prevent such diffusion. However, such barrier layers are not always effective. Therefore, an alternative method of stopping or slowing down such diffusion has been developed by using a gradient layer of concentration between the coating layer and the substrate. This idea can be explained in general in the following way: If it is known that a single-layer oxide coating, represented for example as ABC0X for the purpose of explanation, where A, B and C are metal ions in the coating layer, This color changes, that is, discolours after the heat treatment, because the B ions, for example, diffuse to the glass substrate in exchange with the D ions, for example, the alkali ions, which leave the substrate of glass, a thin film of BOx can be deposited between the glass substrate and the ABCOx coating. As can be appreciated, the invention can be practiced with a single layer oxide coating with two or more metal ions. The B0X layer provides a concentration or sacrificial gradient layer to prevent such discoloration. The ions B of said sacrificial layer diffuse to the glass more easily than the B ions coming from the cover layer ABC0X. Thus, by placing a layer of B0X between the ABCOx layer and the glass, the B ions of the lower coating layer of B0X diffuse partially or completely to the glass. The BOx layer acts as a concentration gradient deterrent layer to prevent or retard the B ions of the topcoat layer or the ABCOx coating layer from diffusing to the glass substrate. Consequently, the B ions of the topcoat layer ABC0X diffuse, if they do, more slowly to the BOx layer of the bottom coat, and thus minimize the degradation of the ABCOx layer while the layer B ions. of lower coating BOx diffuse mostly to the glass and perhaps slightly to the top coating layer. The transmitted color of the coated glass can thus be controlled by the thickness and composition of the BOx layer as well as the thickness and composition of the ABCDX topcoat layer. This results from the fact that, depending on the time, temperature and thickness of the film, most or all of the BOx layer can be decomposed in such a way that substantially only the desired ABCOx top coat layer remains. The BOx layer is preferably deposited directly on the glass substrate, but can also be deposited on another coating layer deposited on the substrate.

To act as a concentration gradient dissolving layer, the B0X layer should be deposited both to minimize a color change in the coated glass and to minimize the diffusion of B ions from the top coating layer to the glass. For example, the Cu?, 4Mn?, 604 blue films described above may be discolored after the heat treatment which results in the breakage of the chromophore crystal structure to the point where the color may no longer be present (eg. example, heating at 650 ° C for 16 hours) and the Cu and Mn ions have diffused to the glass. As explained above, copper is the most mobile species in this system. Therefore, a two layer system was made including glass / Cu? / Cu? / 4Mn? / 604. The experimental results for the deposition of a CuO layer of variable thickness are shown in Table III below. The coatings were deposited on heated pieces of floating glass on the side of the glass not supported on the tin bath during manufacture. The unsupported surface was coated to emulate what is currently done in line to pyrolytically coat or by CVD on a floating tape. The tin-rich surface of the cut glass piece of the floating tape can be coated during laboratory experiments. However, it has been determined that the tin-rich surface of the glass acts as a barrier to the diffusion of ions from a coating to the glass during the heat treatment and that the tin ions act as a barrier. The CuO layer was deposited on the glass followed by the deposition of the Cu? Mn1 / S0 layer on the CuO layer. The thickness of the CuO layer was varied by varying the spray time to apply the copper acetylacetonate suspension on the glass substrate, i.e., a two second spray time produces a resulting CuO layer finer than a Spraying time of eight seconds. The thicknesses of the CuO layers are of the order of from about 50 Á for a spray time from two seconds to about 200 Á for a spray time of eight seconds. As can be appreciated, the invention is not limited to the thickness of the copper oxide layer and, when practicing the present invention, thicknesses of the order of 25 Angstroms (Á) -260 Á are acceptable. The thickness of the Cu1 / 4Mn?, 60 layers was not varied and was approximately 300A. The Cu?, 4Mn?, 601/4 film was deposited by spraying copper (II) and manganese (III) acetylacetonates in the molar ratio of 0.54 for 8 seconds to deposit a layer with a thickness of about 300A. As can be appreciated, the invention is not limited to the thicknesses of the Cu? 4Mn?, S0? 4 films and thicknesses of the order of 100A-700A are acceptable. The thicknesses of the films of the Samples were determined by spectroscopic elipsometry. The effect of discoloration is clearly observed with coatings deposited on glass, for example, glass made by the flotation process; however, for coatings deposited on quartz, the effect of discoloration is not as pronounced as with glass substrates because the ion exchange is small or null between the quartz substrate and the coating because the quartz substrate has ions present in the parts per million, thereby reducing ion exchange.

Table III Effect of the thickness variation of the CuO layer of clear glass samples / Cu? /Cu1.Mn1.604 before and after the heat treatment at 650 ° C for 10 minutes. The movies of CUi.Mni.6O were deposited with a spray time of 8 seconds with a molar ratio of Cu (II) / Mn (III) of 0.54 in the suspension.

The two-layer system (glass / Cu? / Cu?; 4Mn?, 60) did not give the typical blue color associated with a spinel-like phase of Cu? Mn?, 604 due to the presence of the lower layer of CuO of light brown color. The two-layer system was heat-treated for 10 minutes at 650 ° C and compared to a single layer sample deposited and unheated with a phase coating of the Cu spinel type. Mn1 / 60. The results of the variation of the molar ratio of Cu / Mn of 0, 82 to 1.49 in the upper coating with the same lower layer of CuO (the layer next to the glass) and the comparison of the two-layer system in the deposited state with the same two-layer heat-treated systems are set forth in Table IV. After heating each of the two-layer systems, the color transmitted was again blue due to the diffusion of Cu ions from the dissolving CuO layer of concentration gradient in the glass, leaving a desired top layer of the spinel type of Cu? / 4Mn? / 6? 4 blue. The change in transmittance (discoloration)? And, before and after the heat treatment with a two-layer system, was reduced from 11% to 0.75% for a Cu / Mn ratio of 0.82 and 6.4% at 0.26% for a Cu / Mn ratio of 1.00 and 3.4% at -0.32% (darkened after heat treatment) for a Cu / Mn ratio of 1.49. In addition, the? E (FMCII) (the color change in Mac Units Adam for the three samples indicated above) decreased from 18.1 to 3.4, 17.8 to 3.7 and 15.1 to 4.9, respectively, as a result of the presence of the CuO layer on the supported sue of the glass.

Table IV The addition of other metal-containing components, such as acetylacetonates containing transition metals, modifies the reflected and transmitted properties of the coating to alter the color and absorption of the coating. For example, MnCuCr oxide films tend to be neutral gray. Although copper-containing acetylacetonates and manganese-containing acetylacetonates were sprayed as a mixture on the heated substrate in the examples described above, the separated acetylacetonate suspensions can be sprayed sequentially onto a heated substrate to achieve the same desired color. For example, a suspension of a copper-containing material, such as cupric acetylacetonate, may be sprayed onto a heated glass substrate, the substrate is cooled and reheated and then sprayed with a manganese-containing material, such as manganous or manganic acetylacetonate. , to produce the desired color, for example blue, of the Cu-Mn chromophore described above using, for example, the coating device re-presented in Figure 2. The manganous or manganic acetylacetonate can be first sprayed on the substrate, followed by of a separate coating of cupric acetylacetonate. Again the desired color is achieved, regardless of the deposition sequence. Furthermore, as can be seen, the temperature of the substrate during the coating does not limit the invention and any temperature at which coating is produced by pyrolysis, for example 400 ° C and 900 ° C, is acceptable. Furthermore, as can be appreciated, a binary or tertiary metal acetylacetonate can also be used to deposit the films, for example AxBy (C5H702) i, where A or B are metal ions, for example copper or manganese, and x, y 1 is the number of moles to balance the equation for the desired binary acetylacetonate compound. Although the manganous or manganic and cupric acetylacetonate systems described above produced satisfactory blue chromophores, the resulting blue coatings had a relatively poor acid resistance. The following experiment was performed to find the molar ratios of a copper / manganese system to obtain a desired color with durability. The substrates were cleaned as explained above with respect to the substrates of Example number 1. The coating material was a mixture of finely ground manganic, cupric and cobaltic acetylacetonates. The ground materials were suspended in an aqueous suspension; the suspensions with the initial compositions are listed in Table V. The results of eight samples are shown in Table V for different molar ratios of Cu (II) / Mn (III) in suspension. The compositions of the initial mixture and the resulting films were analyzed by CC plasma analysis. It was found that films having blue-gray color in transmittance have a molar ratio of Cu / Mn of the order of about one. The other compositions had amber appearance. The right column of Table V gives the results of the coating checked according to a conventional test ASTM 282-67 (STANDARD TEST METHOD FOR ACID RESISTANCE OF ENAMEL, TEST OF CITRIC ACID IN SITU). A "yes" indicates acceptable durability.

Table V As can be seen now, the addition of cobalt acetylacetonate Co (C5H702) 3 to an acetylacetonate system containing manganese and copper produces a pyrolytic coating of a desired blue-gray color. Said Cu / Mn / Co mixture also provides a much improved resistance to acid. The acid resistance is maximized when the cobalt content of the mixture is greater than about 50% by weight. As explained, this increase in acid resistance was determined visually according to a conventional ASTM 282-67 test (Standard test method for acid resistance of enamels)., citric acid test in situ). It is considered that said increase in acid durability is produced by greater stability of the Co / Cu / Mn matrix compared to the stability of the Cu / Mn matrix. IRON OXIDE COMPOSITIONS Iron oxide coatings formed pyrolytically on glass generally produce a bronze or gold color film in transmission and improve the solar performance of the glass by absorbing, among other things, part of the solar spectrum in the glass. visible region, reducing the heat load through the glass. Iron oxide can be applied to hot glass by pyrolysis by spray or by chemical vapor deposition. For pyrolytic coatings, the preferred method is to spray an iron-containing material, such as an aqueous suspension of ferric acetylacetonate, onto the glass to form the iron oxide coating. The color of the chromophore containing iron can be changed by adding additional metal ions to form a thin film of binary or tertiary metal oxide. For example, a binary Cu-Fe oxide coating tends to have a light grayish amber color in transmission when formed on a clear glass substrate. A tertiary oxide compound formed from materials, for example acetylacetonates, Cu, Cr and Fe produces a dark gray amber absorbent film on a clear glass substrate. In addition, compounds with cobalt, manganese, aluminum, cerium, calcium, titanium, yttrium, zinc, zirconium and tin acetylacetonates can be used to vary the color of the deposited film. A problem with typical iron oxide coatings is that they tend to darken after additional heat treatment, such as quenching or bending. It is considered that said darkening is produced by an increase in crystallization and the size of grain produced at the temperatures necessary for tempering or curvature. Although it may be possible to add a barrier layer between the iron oxide and the glass to help avoid such darkening, said darkening can be decreased by adding a second selected component to the iron oxide system, such as, but not limiting the invention , Ca, Cu, Al, Ce, Mg, Mn, Ti, And, Zn, Zr. Prevention of darkening A suspension of calcium acetylacetonate was mixed with a suspension of iron acetylacetonate of different molar ratios and pyrolytically sprayed onto a heated glass substrate to form a thin film of iron oxide and calcium. The substrate was cleaned as explained above. Two pieces of clear glass of 10.2 cm2 (4 square inches) were sprayed during the time indicated in Table VI with the same molar solution indicated in Table VI. One piece was heat treated. The thicknesses of the film were not measured. The sample F2 had an LTA luminous transmittance measured, as explained above, of 66.94%. After the heat treatment, the LTA was 66.85%, producing an LTA change of less than 1%. The sample Fl, which is a film of FeOx deposited on the piece of glass and then heat-treated (650 ° C, 10 minutes), causes the darkening of the coating with an LTA change of -7.65% (63.32% transmission before heating and 55.67% transmission after heating). Similar results are reported for Ge-Mn oxide and Fe-Zr oxide (Samples F4-F6), where the binary metal oxide changes much less in light transmittance than does the simple metal oxide FeOx (Fl).

Table VI * Transmitted chromaticity values for the deposited film. ** Change of chromaticity values transmitted after heat treatment at 650 ° C, 10 minutes.

ADDITIONAL COLOR OXIDE FILMS IN TRANSMISSION Mauve / lilac films can be produced in transmission with Mn203 oxide films formed on a clear glass substrate. An Mn304 oxide film formed on a clear glass or quartz substrate produces a light amber color in transmission. Said amber colored film can be transformed into a mauve / lilac film by heating, such as by heating the coated substrate at 650 ° for 8-30 minutes. To improve aesthetics, a silicon-containing barrier layer can be used to form a more uniform color. For example, a layer of silicon oxide can first be deposited on the clear floating glass substrate before spraying the suspension of manganese-containing acetylacetonate on the clear float glass. The silicon-containing layer may only be 20 nanometers thick. It has been found that said mauve / lilac coating in transmittance contains mostly Mn203 by X-ray diffraction. The citric acid resistance of the mauve / lila coat was checked by ASTM 282-67 above and it was found that It was durable to citric acid. Co-Mn oxide systems of Co (II), Co (III), Mn (II), Mn (III), suspension combinations can be used in practicing the invention. Two systems used were a Co (II) / Mn (II) system and a Co (III) / Mn (II) system. It has been found that such systems produce coatings having transmitted colors ranging from brown to grayish brown to light green to light yellow-green as seen in naked-eye transmittance under fluorescent lighting conditions when the molar ratio of Co to Mn in the Your pension is varied from 9.0 to 0.1 (See Table VII). By making some suspensions explained above, surfactants were used. As those skilled in the art can appreciate, the use of surfactants has little or no effect on the results obtained.

Table VII CIÉ chromaticity coordinates of reflectance and transmitence for CoMn oxide films on clear glass * See Table I. ** See Table I. *** See Table I.

Those skilled in the art will readily appreciate that modifications can be made to the invention without departing from the ideas described in the foregoing description. Such modifications are to be considered included within the scope of the invention. Accordingly, the particular embodiments described above in detail are illustrative only and do not limit the scope of the invention, to which the full scope of the appended claims and each and every one of their equivalents must be granted.

Claims (45)

Claims

1. A coating method including the steps of: providing a first component; provide a second component; and applying the first and second components on a surface of a substrate to a selected ratio of the first component to the second component to form a coating of a desired color on the surface.

2. A coating method comprising the steps of: providing a mixture having a copper containing component and a manganese containing component and with a selected copper to manganese ratio to obtain a coating of a desired transmittance color; and applying the mixture having the copper and manganese containing components on a surface of a substrate to form the coating having a selected molar ratio of Cu / Mn on the surface.

3. The method claimed in claim 2, wherein the ratio is a molar ratio.

4. The method claimed in claim 2, wherein the selected ratio is about 1 and the coating has a blue color in transmission.

5. The method claimed in claim 2, wherein the selected molar ratio of Cu / Mn in the coating is greater than 1 and the desired color of the coating in transmission varies from blue gray to brown as the ratio increases.

6. The method claimed in claim 2, wherein the selected molar ratio of Cu / Mn in the coating is less than 1 and the desired color of the coating in transmission varies from blue gray to amber as the ratio decreases

7. The method claimed in claim 2, wherein the copper component is an acetylacetonate containing copper and the manganese component is an acetylacetonate containing manganese and where the substrate is heated during the practice of the application step to pyrolyze the coating.

8 • The method claimed in claim 2, wherein the coating is a Cu? / Mn? / 604 having a spinel-type phase to obtain a coating having a blue color in transmission.

9. The method claimed in claim 2, including the step of providing a layer having CuO between the coating and the substrate to prevent discoloration of the coating after heating of the coated substrate.

10. The method claimed in claim 1, further including adding a chromium-containing component to the coating to obtain a coating that is gray in transmission.

11. The method claimed in claim 2, including adding a cobalt-containing component to the coating to improve acid resistance.

12. The method claimed in claim 11, including adding enough cobalt-containing component in such a way that the amount of cobalt in the coating is greater than 50% by weight.

13. A method of preventing discoloration of the color, including the steps of: selecting a desired coating mixture having two or more components to be deposited on a surface of a substrate; determine the component that has the most mobile species; depositing a dissuasive layer of concentration gradient of an oxide of the most mobile species on the surface of the substrate; and applying the coating mixture on the concentration gradient deterrent layer.

14. The method of claim 13, further comprising the step of heating the substrate having the coating and the layer where at least a portion of the more mobile species in the concentration gradient layer diffuses to the substrate to prevent discoloration of the coating.

15. A coating method comprising the steps of: providing a component containing iron having at least one component having at least one of Ca, Al, Ce, Mg, Mn, Ti, Y, Zn and Zr for the coating to avoid the darkening of the coating to the subsequent thermal treatment of the substrate of the coated article; and applying the binary components to the surface of a heated substrate to form an oxide coating on the surface of the substrate.

16. A coating method comprising the steps of: providing a mixture having a copper-containing component and an iron-containing component, and applying the components on a substrate surface to form an oxide coating containing iron and copper to obtain a coated substrate having light gray / amber color in transmission.

17. The method as claimed in claim 16, including the steps of providing a chromium containing component and applying the copper containing and chromium containing components on the substrate surface to form an oxide coating containing iron, copper and chromium to obtain a coated article having a dark gray color amber in transmission, having at least one component of Ca, Al, Ce, Mg, Mn, Ti, Y, Zn and Zr for the coating to avoid the darkening of the coating to the subsequent thermal treatment of the substrate of the coated article.

18. An article made according to the method of claim 1.

19. The article claimed in claim 18, wherein the substrate is a glass substrate.

20. A coating method including the steps of: providing a component containing manganese; and applying the manganese component on the surface of a heated substrate to form an oxide coating containing manganese on the substrate.

21. The method claimed in claim 20, further comprising the step of mixing a cobalt-containing component with the manganese-containing component and applying the mixture on the surface of the heated substrate.

22. The method claimed in claim 20, wherein the manganese-containing oxide coating includes manganic oxide and the color of the coating is mauve / lilac in transmission.

23. The method claimed in claim 20, wherein the oxide coating containing manganese includes Mn30 oxide and the transmitted color of the coating is amber.

24. The method claimed in claim 22, wherein the manganese-containing oxide coating is Mn304 and further comprising the step of heating the substrate having the coating of Mn304 to form a coating of manganic oxide.

25. The method claimed in claim 20, including the step of applying a silicon-containing barrier layer between the substrate and the coating.

26. The method claimed in claim 25, wherein the silicon-containing barrier layer includes silicon oxide.

27. The method of claim 1, wherein the first component contains copper and the second component contains manganese and the components are applied separately.

28. The method of claim 27, wherein the coating color is blue in transmission.

29. The method of claim 27 wherein the copper containing component is applied before the manganese containing component.

30. The method of claim 29, wherein the substrate is heated before applying the manganese containing component.

31. The method of claim 27, wherein the manganese-containing component is applied before the copper-containing component.

32. The method of claim 31, wherein the substrate is heated before applying the copper containing component.

33. A method for forming a graduated coating on a surface of a substrate having a first end and a second end, including the steps of: placing at least one first coating dispenser relative to the first end of the substrate; directing said first coating dispenser towards the substrate in such a way that an axis extending through a dispensing end of said first coating dispenser subtends a predetermined angle with the substrate; and supplying a first coating material to said first coating dispenser in such a way that the coating material is deposited on the substrate to form a graduated coating on the substrate.CJ.

34. The method claimed in claim 33, including heating the substrate in such a manner that the first coating material pyrolyses on the substrate.

35. The method claimed in claim 33, including placing a first exhaust hood on one side of said first coating dispenser and placing a second exhaust hood on the other side of said first coating dispenser.

36. The method claimed in claim 33, including placing at least a second coating dispenser spaced from said first coating dispenser and supplying a second coating material to said second coating dispenser.

37. A manufactured article formed by the method of claim 33.

38. A method of forming a graduated coating on a surface of a substrate, including the steps of: providing a plurality of spaced coating dispensers, each coating dispenser configured to provide a spray pattern having a center on the substrate; direct coating material by coating dispensers; and placing the coating dispensers to form a plurality of coated areas overlapped on the substrate when the substrate moves relative to the coating dispensers to form a graduated coating on the substrate.

39. The method claimed in claim 38, including positioning the coating dispensers such that a coated area formed by a coating dispenser on the substrate does not extend beyond the center of the spray pattern of an adjacent coating dispenser.

40. A manufactured article formed by the method of claim 38.

41. An apparatus for forming a graduated coating on a surface of a substrate, including: a support surface; at least a first coating dispenser having a dispensing end; a source of coating material in flow communication with said first coating dispenser; at least one exhaust hood mounted in predetermined spaced relation to said first coating dispenser; and means for mounting said first coating dispenser relative to said support surface, wherein no protector is placed between said first coating dispenser and said support surface, and wherein an axis extending through said dispensing end subtends a predetermined angle with said support surface in such a way that the coating material is directed from said discharge end to said surface of the substrate to form a graduated coating on the surface of the substrate.

42. The apparatus claimed in claim 41, wherein said predetermined angle is between about 20-40.

43. An apparatus for forming a graduated coating on a surface of a substrate, comprising: a tapered coating dispensing groove having a first end and a second end, decreasing the width of said dispensing groove from said first end to said second extreme; and at least one spaced exhaust groove of said tapered dispensing groove.

44. A manufactured article, including: a substrate that has a surface; and a graduated coating pyrolytically deposited on the surface of the substrate, the coating having variable thicknesses along a predetermined length of the coating.

45. The manufactured article claimed in claim 44, wherein the glass substrate is an architectural window or a transparent automobile window. g? SUM A copper containing component and a manganese containing component are applied on the surface of a substrate to form a coating having a selected copper to manganese ratio to form a desired color. further, the change of color of a coating of multiple components to the subsequent thermal treatment is minimized or avoided by determining the most mobile species in the coating and then placing a concentration gradient layer of an oxide of said mobile species between * the substrate and the coating . Upon subsequent thermal treatment, the mobile species in the gradient layer diffuses to the substrate more easily than the mobile species in the coating. In addition, the change of color due to heating, for example, quenching operations, is minimized by adding calcium to a Fe0x system to avoid darkening the film after heating. An apparatus for forming a graduated coating on a substrate includes a coating station positioned along a conveyor belt. The coating station includes a first coating dispenser pivotally mounted on a first support and at least one exhaust hood. The first coating dispenser is positioned such that an axis through the dispensing end of the first coating dispenser subtends the substrate at a predetermined angle.