Hot end metal oxide coating for glass substrates and containers

Abstract

A method of coating a glass substrate with a hot end coating is provided. The method includes the step of applying an aqueous dispersion comprising particles of a metal hydroxide composition onto a surface of a glass substrate to form a hot end coating on the glass substrate. The temperature of the glass surface is from about 450 DEG C to about 1000 DEG C when the aqueous dispersion is applied to the surface. After application, the hot end coating comprises a metal oxide or a combination thereof. A coated glass article is also provided. A coating on a glass article includes at least one of a group 3A oxide, a group 4A oxide, or a combination thereof; preferably, TiO2, TiO, Ti2O3, TizOa (0 lt; z < = 2 and 0 lt; a < = 3), ZrO2, ZrbOc (0lt; b < = 1 and 0 lt; c < = 2), Al2O3, Al2O, AlO, AlxOy (0lt; x is less than or equal to 2 and 0 lt; y < = 3), or a combination thereof; preferably, Al2O3, Al2O, AlO, AlxOy (0 lt; x is less than or equal to 2 and 0 lt; y < = 3), or a combination thereof.

Description

Technical Field

[0001] The present invention relates to hot end metal oxide coatings for glass articles and substrates such as containers, bottles and flat glass, methods of applying hot end metal oxide coatings during the manufacture of glass articles and substrates, and to glass articles and substrates coated with such coatings. Background Art

[0002] Glass products, especially glass containers and bottles, often require coatings to be applied to their surfaces. The coating imparts desired properties, such as improving adhesion to other coatings, thereby providing additional desired properties (such as scratch resistance and durability). Glass containers, especially glass bottles, can be made by a variety of methods, but they generally have the following steps:

[0003] 1. Melt the sand and modifier at a temperature above 1200°C to form droplets;

[0004] 2. Forming the hot drop into a container;

[0005] 3. Optionally, coat the hot container with a coating. If this coating is applied, it is called a "hot end" coating. The hot end coating protects the glass and acts as a primer for any optional additional coatings, while having suitable optical properties so that the resulting container remains clear and free of iridescence. The hot end coating also provides a surface to which any coatings applied later in the process, such as cold end coatings and / or labels or other markings, can adhere;

[0006] 4. Cooling the hot container. Cooling is done under controlled conditions, as cooling the formed container too quickly will cause the container to break; and

[0007] 5. Optionally, apply a coating to the cooled glass container. If such a coating is applied, it is called a "cold end" coating and typically includes a wax. These cold end coatings can impart properties such as improved lubricity (e.g., for easier automated handling), scratch resistance, improved durability and strength, and / or improved label adhesion.

[0008] There is a desire to improve the efficiency and safety of hot-end coating processes. Currently, some hot-end precursors (such as monobutyltin trichloride, tin tetrachloride, or titanium isopropoxide) are applied to hot glass substrates using chemical vapor deposition. In chemical vapor deposition, the material to be used as the coating is volatilized, typically by liquid evaporation, generally at high temperature and atmospheric pressure. The vapor is deposited on and / or reacts with the hot glass surface. Such a coating (hot-end coating) protects the glass container and serves as a primer for a subsequently deposited cold-end coating, which adheres to the metal oxide surface and protects the glass from scratching and helps maintain the glass strength. Tin precursors are strongly acidic, and the HCl released by the CVD reaction corrodes the coating equipment used to apply them. Alternatives to traditional tin precursors, such as titanium isopropoxide, are flammable and may be harmful to health. During the CVD process, fouling may occur on the coating equipment over time, leading to process stoppages for regular equipment maintenance and cleaning, which is inefficient and costly.

[0009] Other coating methods have been described in EP 3 024 792; WO 2012 / 053919; and "Processing, Properties, and Applications of Glass and Optical Materials: Ceramic Transactions", edited by Arun K.

[0010] Varshneya, Helmut A. Schaeffer, Kathleen A. Richardson, Marlene Wightman, and L. David Pye (2012). The above publications disclose a method of applying Al(OH)3 powder to hot and / or cold glass containers to form a coating. A process is described therein. In order to be able to apply the nano-powder on the glass, dry grinding of the starting material is carried out using a mill, and the mill used may be prone to contaminating the powder and thus the resulting coating. In addition, applying the powdered coating to the hot glass surface may also have adverse environmental and safety limitations due to the need to contain the powder.

[0011] WO 2006 / 060510 describes an alumina dispersion.

[0012] Accordingly, there is a need for a method of applying a hot-end coating to a glass substrate that is non-corrosive, harmless, produces little to no harmful emissions, and avoids buildup on the equipment, while being efficient, cost-effective, safe, environmentally friendly, and achieving the performance and characteristics required for a hot-end coating, such as being substantially transparent, substantially colorless, and free of iridescence. Summary of the Invention

[0013] The inventors have surprisingly found that an aqueous dispersion of solid particles comprising a metal hydroxide composition can be directly applied to the hot surface of a glass substrate to form a suitable hot-end coating. The temperature of the glass substrate surface can be from about 450 °C to about 1000 °C. The inventors have also found that spraying the aqueous dispersion is a suitable method for applying the coating to the heated surface. After spraying the aqueous dispersion onto the hot glass, a coating comprising a metal oxide is formed on the glass substrate. The deposited metal oxide coating appears to the naked eye to be substantially transparent or transparent, substantially colorless or colorless, and / or substantially non-iridescent or non-iridescent. Optionally, after applying the hot-end coating according to the present invention to the glass surface, an additional cold-end coating (preferably in the form of a polymer formulation) can be deposited onto and adhered to the hot-end coating.

[0014] Accordingly, there is provided a method of coating a glass substrate with a coating. The coating is a hot-end coating. The coating is inorganic. The method comprises the steps of:

[0015] a) applying an aqueous dispersion of particles comprising a metal hydroxide composition to the surface of a glass substrate, the surface having a temperature of from about 450 °C to about 800 °C, thereby forming a hot-end coating on the glass substrate. In various embodiments, the temperature of the surface is 450 °C to 1000 °C before, at the first application, or after applying the aqueous dispersion. After applying the aqueous dispersion, the hot-end coating comprises a metal oxide or a combination thereof.

[0016] There is also provided a coated glass article. The article comprises a glass substrate and a hot-end coating on the glass substrate. The coating comprises at least one of a Group 3A oxide, a Group 4A oxide, or a combination thereof; preferably TiO2, TiO, Ti2O3, Ti z O a (0 < z ≤ 2 and 0 < a ≤ 3), ZrO2, Zr b O c (0 < b ≤ 1 and 0 < c ≤ 2), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3) or a combination thereof. Brief Description of the Drawings

[0017] Figure 1Shows a scanning electron microscope (SEM) image of an alumina hot-end coating sample on soda-lime glass taken at a magnification of 50 times according to an embodiment of the present invention. The aqueous dispersion was sprayed at 15 psi.

[0018] Figure 2 Shows SEM images of different alumina hot-end coating samples on soda-lime glass taken at a magnification of 50 times according to an embodiment of the present invention. The aqueous dispersion was sprayed at 15 psi.

[0019] Figure 3 Shows, according to another embodiment of the present invention, an SEM image of the same alumina hot-end coating sample on soda-lime glass (as Figure 2 shown) taken at a magnification of 50 times. The aqueous dispersion was sprayed at 30 psi. Detailed Description

[0020] A method of coating a glass substrate with a coating is provided. The coating is a "hot-end" coating, and optionally a "cold-end" coating is applied thereon.

[0021] The method includes the following steps:

[0022] a) Applying an aqueous dispersion of particles comprising a metal hydroxide composition to the surface of the glass substrate, the surface being at a temperature of about 450 °C to about 1,000 °C, thereby forming a hot-end coating on the glass substrate. After applying the aqueous dispersion, the hot-end coating comprises a metal oxide or a combination thereof.

[0023] According to one embodiment, the method may further include the following steps:

[0024] b) Optionally cooling the glass substrate and the hot-end coating to a temperature of about 80 °C to about 350 °C, preferably about 100 °C to about 250 °C, more preferably about 100 °C to about 200 °C; and

[0025] c) Optionally applying a cold-end coating to the hot-end coating.

[0026] According to another embodiment, the aqueous dispersion is applied by spraying. Spraying can be carried out using a sprayer equipped with a nozzle through which the aqueous dispersion can be atomized at a pressure of about 2 to about 100 psi, preferably about 2 to about 70 psi. The type of sprayer is not particularly limited, but for example, compressed gas such as nitrogen, or oxygen or air can be used as the propellant. The sprayer can be of the airless type, in which case the aqueous dispersion is pressurized and no propellant is used. Non-limiting examples of sprayers that can be used are hydraulic, pneumatic or mechanical atomizers, or combinations thereof. Other non-limiting examples of sprayers that can be used are ultrasonic atomizers, rotary atomizers, airless atomizers or electrostatic atomizers, and such sprayers can also be characterized by the geometry and configuration of the nozzle and orifice, spray pattern, droplet size and the droplet size distribution that may be produced. Several such techniques are discussed in "Atomization and Sprays" by Arthur Lefebvre and Vincent McDonell, 2nd Edition (CRC Press, 2017) and "Classification of Atomization Devices" by A.Yu Vasilyev, E.S.Domrina, S.V.Kaufman and A.I.Maiorova, Journal of Physics: Conference Series 1359 (2019)

[0027] Several such techniques are discussed in 012131, the content of which is incorporated herein by reference.

[0028] The viscosity of the aqueous dispersion can be from about 1 x 10 -5 Pa·s to about 100,000 Pa·s, preferably from about 1 x 10 -4 to about 10,000 Pa·s, more preferably from about 1 x 10 -4 to about 1,000 Pa·s, measured at a shear rate of 0.1 s -1 at 25 °C. The aqueous dispersion can be a Newtonian or non-Newtonian fluid.

[0029] According to one embodiment, the application of the aqueous dispersion of the metal hydroxide composition to the surface of the hot glass substrate is carried out in air and at atmospheric pressure. The atmospheric pressure refers to the pressure around the hot glass substrate and not the pressure that can be used to spray the aqueous dispersion of the metal hydroxide composition.

[0030] Glass substrate:

[0031] Non-limiting examples of suitable glass substrates can be silicate glass, quartz glass, borosilicate glass, soda-lime glass, crystal glass, aluminosilicate glass, germanosilicate glass, phosphosilicate glass, or crown glass. The glass substrate can include 1 to 100 wt% SiO2. The glass substrate can contain other elements such as sodium, calcium, aluminum, iron, magnesium, boron, lead, sulfur, carbon, selenium, chromium, cobalt, nickel, manganese, phosphorus, germanium, and / or potassium. The glass substrate can include 0 to 100 wt% recycled glass.

[0032] Aqueous dispersion

[0033] The aqueous dispersion contains (solid) particles of the metal hydroxide composition. The volume average particle size of the particles can be from about 1 nm to about 100 microns, or from about 1 nm to about 50 microns, or from about 1 nm to about 25 microns, or from about 1 nm to about 10 microns, or from about 1 nm to about 5 microns, measured by X-ray diffraction or light scattering. Suitable measurement techniques depend on the particle size. For example, the particle size range can be unimodal, bimodal, or multimodal.

[0034] As described above, when sprayed onto the surface of the glass substrate, the temperature of the aqueous dispersion can be from about 10 °C to about 70 °C, from about 15 °C to about 60 °C, preferably from about 20 °C to about 50 °C. Surprisingly, despite the large temperature difference between the aqueous dispersion and the glass substrate surface, the glass substrate does not break or weaken when applying a (relatively) cold aqueous dispersion. The pH of the aqueous dispersion can be less than about 8, preferably from about 1 to about 7, more preferably from about 2 to about 7, and most preferably from about 3 to about 7.

[0035] The aqueous dispersion can also include at least one acid, preferably an inorganic acid, or a combination thereof. Suitable acids preferably include at least one of nitric acid, acetic acid, formic acid, hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, or a combination thereof. The acid more preferably includes nitric acid, formic acid, or a combination thereof. The acid most preferably includes nitric acid. A certain amount of acid or a combination of acids is added to achieve the pH required for the aqueous dispersion applied to the surface of the glass substrate to form a hot-end coating. According to one embodiment, the aqueous dispersion can be formed with deionized water. According to one embodiment, the aqueous dispersion can be formed with tap water.

[0036] The aqueous dispersion can include solid particles of the metal hydroxide composition in an amount of about 1 to about 70 wt%, preferably about 2 to about 70 wt%, more preferably about 5 to about 70 wt%, and most preferably about 10 to about 70 wt% based on the weight of the aqueous dispersion.

[0037] The dispersion may further comprise at least one salt, the at least one salt preferably comprising at least one of Group 3A or Group 4 elements or a combination thereof, more preferably an aluminum salt, and even more preferably at least one salt comprising at least one of aluminum nitrate (Al(NO3)3), aluminum sulfate (Al2(SO4)3), aluminum lactate, aluminum acetate, aluminum formate, aluminum stearate or a combination thereof. The aqueous dispersion may comprise from about 1 to about 10 wt% of the salt, preferably from about 3 to about 8 wt% of the salt, more preferably from about 4 to about 8 wt% of the salt, based on the weight of the aqueous dispersion.

[0038] According to one embodiment, an aqueous dispersion of solid particles comprising a metal hydroxide composition may have a viscosity at a shear rate of 0.1 s -1 of about 1,000 Pa·s or less, measured at 25 °C. The aqueous dispersion may comprise particles of the metal hydroxide composition having a volume average particle size of 10 microns or less, which particle size is determined by X-ray diffraction or light scattering. The viscosity of the fluid may be Newtonian or non-Newtonian.

[0039] Other additives:

[0040] An aqueous dispersion of solid particles comprising a metal hydroxide composition may further comprise additional additives known and used in the art. For example, the aqueous dispersion may comprise one or more of a wetting agent, a surfactant, a viscosity modifier, a preservative, a co-solvent, a stabilizer or an antibacterial additive.

[0041] Metal hydroxide composition:

[0042] According to certain embodiments, the metal hydroxide composition comprises at least one of a Group 3A hydroxide, a Group 4 hydroxide or a combination thereof; preferably titanium hydroxide, zirconium hydroxide, aluminum hydroxide, αAlO(OH), γAlO(OH), 5Al2O3·H2O or a combination thereof; more preferably γAlO(OH). After applying the metal hydroxide composition to the hot surface of a glass substrate, the resulting hot-end coating comprises a metal oxide; the metal oxide comprises at least one of a Group 3A oxide, a Group 4A oxide or a combination thereof; preferably Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), TiO2, TiO, Ti2O3Ti z O a (0 < z ≤ 2 and 0 < a ≤ 3), ZrO2, Zr b O c (0 < b ≤ 1 and 0 < c ≤ 2), Al2O3, Al2O, AlO, AlO, Al x O y(0 < x ≤ 2 and 0 < y ≤ 3), or combinations thereof; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or combinations thereof.

[0043] Solid particles of the metal hydroxide composition having a BET surface area measured by the nitrogen adsorption method of 50 to 300 m 2 / g, or 75 to 200 m 2 / g. The solid particles of the metal hydroxide composition may have a crystallite size (120 plane) of 50 to or 50 to , as measured by X-ray diffraction. The porosity of the solid particles of the metal hydroxide composition measured using the nitrogen desorption method may be less than 1 ml / gm, preferably 0.3 to 0.9 ml / g.

[0044] Hot-end coating:

[0045] After application to the hot surface of the glass substrate, the resulting coating ("hot end" coating) comprises metal oxides. These metal oxides comprise at least one of Group 3A oxides, Group 4A oxides or combinations thereof; preferably Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), TiO2, TiO, Ti2O3, Ti z O a (0 < z ≤ 2 and 0 < a ≤ 3), ZrO2, Zr b O c (0 < b ≤ 1 and 0 < c ≤ 2), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or combinations thereof; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or combinations thereof.

[0046] The coating may be an inorganic coating. According to certain embodiments, the coating formed from the aqueous dispersion of the metal hydroxide is substantially free of halides, preferably substantially free of Cl. Substantially free of halides means that the content of halides is less than 10 wt%, or less than 5 wt%, or 1 wt% or less, or 5000 ppm or less, or 1000 ppm or less, or 500 ppm or less, or 100 ppm or less, or 50 ppm or less, or 10 ppm or less, based on the weight of the hot end coating.

[0047] According to one embodiment, the coating is substantially free of carbon. Substantially free of carbon means that based on the weight of the hot-end coating, the carbon content is less than 10 wt%, or less than 5 wt%, or 1 wt% or less, or 5000 ppm or less, or 1000 ppm or less, or 500 ppm or less, or 100 ppm or less, or 50 ppm or less, or 10 ppm or less.

[0048] According to certain embodiments, the hot-end coating may be substantially free of metals other than aluminum. Substantially free of metals other than aluminum means that based on the weight of the hot-end coating, the content of metals other than aluminum is less than 1

[0049] wt%, or less than 5000 ppm, or less than 1000 ppm, or less than 500 ppm.

[0050] According to one embodiment, the coating comprises Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3) or at least one of their combinations; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3) or their combinations; and the coating is substantially free of halogens, carbon, and metals other than aluminum.

[0051] According to one embodiment, the volume average particle size of the metal oxides in the hot-end coating can be 50 microns or less. According to another embodiment, the volume average particle size measured by scanning electron microscopy or X-ray diffraction or light scattering can be from 1 nm to about 50 microns, or preferably from about 10 nm to about 10 microns.

[0052] According to one embodiment, the resulting coating comprising (one or more) metal oxides appears substantially transparent, colorless, and / or iridescent-free to the naked eye. As defined herein, transparent means capable of transmitting light such that the human naked eye can see through it. As defined herein, iridescence means that the coating has a rainbow effect or appearance observable by the naked eye. As defined herein, colorless means that no color can be discerned by the naked eye. According to one embodiment, the resulting hot-end coating comprising (one or more) metal oxides is uniform. As defined herein, uniform means that the hot-end coating and / or the (one or more) metal oxides comprised in the hot-end coating have a visually uniform appearance. According to one embodiment, the hot-end coating forms a continuous or discontinuous film when and / or after the aqueous dispersion is applied to the hot glass substrate.

[0053] According to one embodiment, the cold-end coating can adhere to the hot-end coating comprising (one or more) metal oxides.

[0054] According to one embodiment, the coated glass article includes at least one of a hollow glass container, a bottle, or a flat glass.

[0055] Emissions during coating:

[0056] According to one embodiment, the coating process results in the release (emission) of substantially only water. As used herein, "substantially only water" means that the emission of halogen and / or carbon resulting from the coating process is < 10%, or

[0057] < 5%, < 3%, < 2%, < 1%, < 0.5%, based on the weight of the aqueous dispersion composition (applied to the hot surface of the glass substrate to produce a metal oxide hot-end coating on the surface of the glass substrate).

[0058] Coated glass article:

[0059] There is provided a coated glass substrate produced by the method disclosed herein. The coated glass article includes:

[0060] a glass substrate and

[0061] a hot-end coating on the glass substrate,

[0062] wherein the hot-end coating comprises at least one of a Group 3A oxide, a Group 4A oxide, or a combination thereof; preferably TiO2, TiO, Ti2O3, Ti z O a (0 < z ≤ 2 and 0 < a ≤ 3), ZrO2, Zr b O c (0 < b ≤ 1 and 0 < c ≤ 2), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof.

[0063] According to one embodiment, the hot-end coating is substantially free of halides, preferably substantially free of Cl. As used herein, substantially free means that based on the weight of the hot-end coating, the content of halides is less than 1 wt%, or less than 5000 ppm, or less than 1000 ppm, or less than 500 ppm, or less than 100 ppm, or less than 50 ppm, or less than 10 ppm. According to one embodiment, an aqueous dispersion can be formed with deionized water. According to one embodiment, an aqueous dispersion can be formed with tap water. According to one embodiment, the hot-end coating is substantially free of carbon. Substantially free of carbon means that based on the weight of the hot-end coating, the carbon content is less than 1 wt%, or less than 5000 ppm, or less than 1000 ppm, or less than 500 ppm, or less than 100 ppm. According to certain embodiments, the hot-end coating can be substantially free of metals other than aluminum. Substantially free means that based on the weight of the hot-end coating, the content of metals other than aluminum is less than 1 wt%, or less than 5000 ppm, or less than 1000 ppm, or less than 500 ppm.

[0064] According to one embodiment, the hot-end coating comprises Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3) or at least one of its combinations; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3) or its combination; and the coating is substantially free of metals other than aluminum. Substantially free means that based on the weight of the hot-end coating, the content of metals other than aluminum is less than 1 wt%, or less than 5000 ppm, or less than 1000 ppm, or less than 500 ppm.

[0065] According to one embodiment, the coated glass article further includes a cold-end coating on the hot-end coating. According to one embodiment, the coated glass article includes at least one of a hollow glass container, a bottle, or a flat glass.

[0066] Exemplary aspects of the present invention can be summarized as follows.

[0067] Aspect 1: A method for coating a glass substrate with a hot-end coating, which includes:

[0068] a) applying an aqueous dispersion containing particles of a metal hydroxide composition to the surface of the glass substrate, the temperature of the surface being about 450 °C to about 800 °C, thereby forming a hot-end coating on the glass substrate;

[0069] wherein, after the application, the hot-end coating contains (one or more) metal oxides or their combinations.

[0070] Aspect 2. The method according to aspect 1, wherein the emissions produced by the method according to aspect 1 consist essentially of only water and are substantially free of halogens and / or carbon.

[0071] Aspect 3: The method according to aspect 1 or aspect 2, wherein the metal hydroxide composition comprises at least one of a Group 3A hydroxide, a Group 4 hydroxide, or a combination thereof; preferably titanium hydroxide, zirconium hydroxide, aluminum hydroxide, αAlO(OH), γAlO(OH), 5Al2O3·H2O, or a combination thereof; more preferably γAlO(OH); and / or wherein after application, the coating comprises a metal oxide, the metal oxide comprising at least one of a Group 3A oxide, a Group 4A oxide, or a combination thereof; preferably Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), TiO2, TiO, Ti2O3, Ti z O a (0 < z ≤ 2 and 0 < a ≤ 3), ZrO2, Zr b O c (0 < b ≤ 1 and 0 < c ≤ 2), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof.

[0072] Aspect 4: The method according to any one of aspects 1 - 3, wherein the pH of the aqueous dispersion is less than 8, preferably about 1 to about 7, more preferably about 2 to about 7, and most preferably about 3 to about 7.

[0073] Aspect 5: The method according to any one of aspects 1 - 4, wherein the aqueous dispersion further comprises at least one or more acids or a combination thereof; preferably nitric acid, formic acid, hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, or a combination thereof; more preferably nitric acid, formic acid, or a combination thereof; most preferably nitric acid.

[0074] Aspect 6: The method according to any one of aspects 1 - 5, wherein the aqueous dispersion comprises solid particles of the metal hydroxide composition in an amount of about 1 to 70% by weight, more preferably about 5 to about 70% by weight, and most preferably about 10 to about 70% by weight of the aqueous dispersion.

[0075] Aspect 7: The method according to any one of aspects 1-6, wherein the aqueous dispersion further comprises at least one salt, and the at least one salt preferably comprises at least one element of Group 3A or Group 4 or a combination thereof, preferably an aluminum salt, more preferably at least one salt comprising at least one of aluminum nitrate (Al(NO3)3), aluminum sulfate (Al2(SO4)3), aluminum lactate, aluminum acetate, aluminum formate, aluminum stearate or a combination thereof.

[0076] Aspect 8: The method according to any one of aspects 1-7, further comprising:

[0077] b) optionally cooling the glass substrate and the hot-end coating to a temperature of about 80 °C to about 350 °C, preferably about 100 °C to about 250 °C, more preferably about 100 °C to about 200 °C; and

[0078] c) applying a cold-end coating onto the hot-end coating, the hot-end coating adhering to the coated glass surface.

[0079] Aspect 9: The method according to any one of aspects 1-8, wherein the aqueous dispersion is applied by spraying, optionally at an aqueous dispersion pressure of about 2 to about 100 psi, preferably at a pressure of about 2 to about 70 psi.

[0080] Aspect 10: The method according to any one of aspects 1-9, wherein the spraying is carried out by a hydraulic, pneumatic and / or mechanical atomizer or a combination thereof, preferably at least one of an air atomizer, an ultrasonic atomizer, a rotary atomizer, a paint spray gun and an electrostatic atomizer.

[0081] Aspect 11: The method according to any one of aspects 1-10, wherein the hot-end coating is substantially free of halides, preferably substantially free of Cl.

[0082] Aspect 12: The method according to any one of aspects 1-11, wherein the hot-end coating is substantially free of carbon.

[0083] Aspect 13: The method according to any one of aspects 1-12, wherein the method is carried out in air at atmospheric pressure.

[0084] Aspect 14: The method according to any one of aspects 1-13, wherein the hot-end coating comprises Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3) or at least one combination thereof; more preferably Al2O3, Al2O, AlO, Al x O y(0 < x ≤ 2 and 0 < y ≤ 3) or a combination thereof; and wherein the hot end coating is substantially free of metals other than aluminum.

[0085] Aspect 15: The method according to any one of aspects 1 - 14, wherein the hot end coating is substantially transparent, colorless, and / or non-iridescent to the naked eye.

[0086] Aspect 16: The method according to any one of aspects 1 - 15, wherein the aqueous dispersion of solid particles comprising the metal hydroxide composition has a viscosity of 1,000 Pa·s measured at a shear rate of 0.1 s -1 or lower at 25°C, and the volume average particle size of the particles is 100 microns or less, preferably 1 nm to 10 microns (determined by X-ray diffraction or light scattering).

[0087] Aspect 17: The method according to any one of aspects 1 - 16, wherein the hot end coating is uniform.

[0088] Aspect 18: The method according to any one of aspects 1 - 17, wherein the aqueous dispersion of solid particles comprising the metal hydroxide composition further comprises at least one or a combination of a wetting agent, a surfactant, a viscosity modifier, a preservative, a stabilizer, an antibacterial additive.

[0089] Aspect 19: A coated glass substrate produced by the method according to any one of aspects 1 - 18.

[0090] Aspect 20: A coated glass article comprising:

[0091] a glass substrate and

[0092] a hot end coating on the glass substrate;

[0093] the hot end coating comprises at least one or a combination of oxides of Group 3A, oxides of Group 4A; preferably TiO2, TiO, Ti2O3, Ti z O a (0 < z ≤ 2 and 0 < a ≤ 3), ZrO2, Zr b O c (0 < b ≤ 1 and 0 < c ≤ 2), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof.

[0094] Aspect 21: A coated glass article as described in aspect 20, wherein the hot-end coating is substantially free of halides, preferably substantially free of Cl and substantially free of carbon.

[0095] Aspect 22: A coated glass article as described in any one of aspects 20-21, wherein the coated glass article comprises at least one of a hollow glass container or a flat glass.

[0096] In this specification, the embodiments have been described in a manner that enables a clear and concise description, but it is intended and should be understood that the embodiments can be combined or separated in various ways without departing from the present disclosure. For example, it should be understood that all the preferred features described herein apply to all aspects of the present invention described herein.

[0097] In some embodiments, the invention herein can be construed as not including any element or process step that does not materially affect the basic and novel characteristics of the composition, the method of making the composition, the method of using the composition, and the article prepared from the composition. In addition, in some embodiments, the present invention can be construed as not including any element or method not specified herein.

[0098] Although the present invention has been shown and described with reference to specific embodiments, the present invention is not intended to be limited to the details shown. Instead, various modifications can be made in the details within the scope of equivalents of the claims without departing from the present invention.

[0099] Examples

[0100] Method :

[0101] Measure the temperature of the glass substrate with a pyrometer (the emissivity of the coated soda-lime glass surface is 0.95)

[0102] Measure the viscosity of the dispersion using an Anton Paar MCR (Modular Compact Rheometer) 502 stress-controlled rheometer in the low shear rate range (0.1–10 s -1 )). The test is carried out using a double-wall Couette, where there are two gaps, one between the outer wall of the cup and the outer periphery of the rotor, and the other between the inner wall of the cup and the inner periphery of the rotor (the outer gap is 0.918 mm and the inner gap is 0.837 mm).

[0103] The volume-average particle size of the particles in the aqueous dispersion was measured by X-ray diffraction technology in transmission mode using a Rigaku SmartLab diffractometer (instrument model with capillary holder). The data was analyzed using NANO solver software version 3, and light scattering measurement data was obtained using a Mastersizer 3000 from Malvern. As is well known in the art, X-ray diffraction is used to measure volume-average particle sizes of about 300 nm and smaller. Light scattering is used to measure volume-average particle sizes of about 100 nm and larger.

[0104] Scanning electron microscopy was performed using a Hitachi SU 8010 instrument.

[0105] First, an aqueous dispersion of hydroxyoxide (hydroxide) was prepared. An aqueous dispersion was formed using hydrated alumina (aluminum hydroxide, also known as aluminum oxyhydroxide) produced by Sasol Chemical. The powder. The volume-average particle size of the particles in the dispersion was 18 nm. Then, at a temperature above 400 °C, the aqueous dispersion was sprayed onto the surface of soda-lime glass. When spraying the aqueous dispersion, the temperature of the soda-lime glass was 530 - 540 °C. At a shear rate of 0.1 s -1 , the viscosity of the measured aqueous dispersion was: 10 wt% dispersion: viscosity = 4.3x10 -3 Pa·s; 30 wt% dispersion: viscosity = 20 Pa·s.

[0106] By adding the powder slowly to deionized water, a dispersion of aluminum hydroxyoxide was prepared, thereby preparing an aqueous dispersion containing 5 to 35 wt% of aluminum hydroxyoxide by weight of the aqueous dispersion. During the preparation, even after the powder was completely dissolved in water, the dispersion was continuously stirred. A clean piece of soda-lime glass was placed on a hot plate and annealed to a temperature above 400 °C, measured using a pyrometer. When the glass temperature reached 400 °C or higher, the prepared aqueous dispersion was sprayed onto the hot glass surface using a spray gun (Grex, model Tritium) equipped with a corona nozzle. Depending on the concentration of the aqueous dispersion, the air pressure in the spray gun varied between 10 and 40 psi. Higher concentrations of the dispersion used higher pressures. After applying the aqueous dispersion, the glass substrate and its hot-end coating were cooled to 125 °C. The coating was transparent and had no iridescence. The volume-average particle size of the metal oxide layer containing the hot-end coating was measured to be less than 200 nm using scanning electron microscopy. When the glass substrate and its hot-end coating reached 125 °C, a wax emulsion cold-end coating ( RP-40, Arkema) was sprayed onto the hot-end coating using the same spray gun at an air pressure of 15 psi (nozzle fully open).

[0107] The SEM image of the metal oxide coating is as Figures 1-3 shown. As shown in the figure, the metal oxide coating is in the form of "islands" and is distributed substantially uniformly on the surface of the soda-lime glass substrate. The composition of these islands can be substantially homogeneous or heterogeneous. The volume average particle size of these islands was reported above as the volume average particle size of the metal oxide layer. The metal oxide coating can form a continuous thin film.

Claims

1. A method for coating a glass substrate with a hot-end coating, which comprises: a) applying an aqueous dispersion of particles comprising a metal hydroxide composition onto the surface of the glass substrate, the temperature of the surface being from about 450 °C to about 800 °C, thereby forming a hot-end coating on the glass substrate; wherein, after application, the hot-end coating comprises a metal oxide or a combination thereof.

2. The method according to claim 1, wherein the emissions generated by the method according to claim 1 consist essentially only of water and are substantially free of halogens and / or carbon.

3. The method according to claim 1 or claim 2, wherein the metal hydroxide composition comprises at least one of group 3A hydroxides and group 4 hydroxides, or a combination thereof; preferably titanium hydroxide, zirconium hydroxide, aluminum hydroxide, α-AlO(OH), γ-AlO(OH), 5Al2O3·H2O, or a combination thereof; more preferably γ-AlO(OH); and / or wherein after application, the coating comprises a metal oxide, the metal oxide comprising at least one of group 3A oxides and group 4A oxides, or a combination thereof; preferably Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), TiO2, TiO, Ti2O3, Ti z O a (0 < z ≤ 2 and 0 < a ≤ 3), ZrO2, Zr b O c (0 < b ≤ 1 and 0 < c ≤ 2), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and (0 < y ≤ 3), or a combination thereof; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof.

4. The method according to any one of claims 1-3, wherein the pH of the aqueous dispersion is less than 8, preferably from about 1 to about 7, more preferably from about 2 to about 7, and most preferably from about 3 to about 7.

5. The method according to any one of claims 1-4, wherein the aqueous dispersion further comprises at least one or more acids or a combination thereof; preferably nitric acid, formic acid, hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid or a combination thereof; more preferably nitric acid, formic acid or a combination thereof; most preferably nitric acid.

6. The method according to any one of claims 1-5, wherein the aqueous dispersion comprises solid particles of the metal hydroxide composition in an amount of about 1 to 70% by weight, more preferably about 5 to about 70% by weight, and most preferably about 10 to about 70% by weight of the aqueous dispersion.

7. The method according to any one of claims 1-6, wherein the aqueous dispersion further comprises at least one salt, the at least one salt preferably comprising at least one or a combination of elements from Group 3A or Group 4, preferably an aluminum salt, more preferably at least one salt comprising at least one or a combination of aluminum nitrate Al(NO3)3, aluminum sulfate (Al2(SO4)3), aluminum lactate, aluminum acetate, aluminum formate, aluminum stearate.

8. The method according to any one of claims 1-7, which further comprises: b) optionally cooling the glass substrate and the hot-end coating to a temperature of about 80 °C to about 350 °C, preferably about 100 °C to about 250 °C, more preferably about 100 °C to about 200 °C; and c) applying a cold-end coating onto the hot-end coating, the hot-end coating adhering to the coated glass surface.

9. The method according to any one of claims 1-8, wherein the aqueous dispersion is applied by spraying, optionally at an aqueous dispersion pressure of about 2 to about 100 psi, preferably at a pressure of about 2 to about 70 psi.

10. The method according to any one of claims 1-9, wherein spraying is carried out by a hydraulic, pneumatic and / or mechanical atomizer or a combination thereof, preferably at least one of an air atomizer, an ultrasonic atomizer, a rotary atomizer, a paintless atomizer and an electrostatic atomizer.

11. The method according to any one of claims 1-10, wherein the hot-end coating is substantially free of halides, preferably substantially free of Cl.

12. The method according to any one of claims 1-11, wherein the hot-end coating is substantially free of carbon.

13. The method according to any one of claims 1-12, wherein the method is carried out in air at atmospheric pressure.

14. The method according to any one of claims 1-13, wherein the hot end coating comprises Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3) or at least one of their combinations; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3) or their combinations; and wherein the hot end coating is substantially free of metals other than aluminum.

15. The method according to any one of claims 1 - 14, wherein the hot - end coating is substantially transparent, colorless, and / or non - iridescent to the naked eye.

16. The method according to any one of claims 1-15, wherein the aqueous dispersion of solid particles comprising the metal hydroxide composition has a viscosity of 1,000 Pa·s measured at a shear rate of 0.1 s -1 or less at 25°C, and the volume average particle size of the particles determined by X-ray diffraction or light scattering is 100 microns or less, preferably 1 nm to 10 microns.

17. The method according to any one of claims 1 - 16, wherein the hot - end coating is uniform.

18. A coated glass substrate produced by the method according to any one of claims 1 - 17.

19. A coated glass article, comprising: a glass substrate and a hot - end coating on the glass substrate; The hot-end coating contains at least one or a combination of oxides of Group 3A and Group 4A; preferably TiO2, TiO, Ti2O3, Ti z O a (0 < z ≤ 2 and 0 < a ≤ 3), ZrO2, Zr b O c (0 < b ≤ 1 and 0 < c ≤ 2), Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof; more preferably Al2O3, Al2O, AlO, Al x O y (0 < x ≤ 2 and 0 < y ≤ 3), or a combination thereof.

20. The coated glass article according to claim 19, wherein the hot - end coating is substantially free of halides, preferably substantially free of Cl and substantially free of carbon.

21. The coated glass article according to any one of claims 19 - 20, wherein the coated glass article comprises at least one of a hollow glass container or a flat glass.

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