Coating composition for forming display coating layer and glass assembly and window assembly comprising the display coating layer
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- SAINT GOBAIN SEKURIT FRANCE
- Filing Date
- 2023-07-10
- Publication Date
- 2026-07-08
Smart Images
Figure 1.1
Abstract
Description
Coating composition for forming display coating layer and glass assembly and window assembly comprising the display coating layerTechnical Field
[0001] The present disclosure relates to the technical field of glass, in particular to a coating composition for forming a display coating layer, and a glass assembly and a window assembly comprising the display coating layer.Background
[0002] Currently consumers in the market have an increasing and strong interest in glass products with display function (such as a vehicle glass, a building exterior wall glass, etc. ) . This kind of glass products have multiple functions, such as practicality and aesthetics, and provide consumers with a good user experience. As a result, there is a growing demand for glass products with display function in the market.
[0003] In the prior art, polymer-based flexible projection display films can be used to provide glass with display functions. The polymer-based film can be used as an intermediate layer and laminated between glass panes. It is also possible to adhere the polymer-based film directly to the outer surface of the glass, for example, to the outer side of a vehicle glass. However, the assembly process of glass products obtained by using polymer-based display films is very complicated and time-consuming, which is prone to defects and thus adversely affect the visual effect. At the same time, the cost of such products is relatively high, which is not conducive to large-scale market application.
[0004] In addition, products with display function based on Thin Film Transistor (TFT) technology, such as Thin Film Transistor-Liquid Crystal Display (TFT-LCD) and Thin Film Transistor-Light Emitting Diode (TFT-LED) , can also provide display function for consumers. In TFT display panels, various films necessary for manufacturing circuits are formed on the glass by sputtering or chemical deposition processes, and large-scale semiconductor integrated circuits are created by processing the films. However, due to factors like raw materials, processing and so forth, such products are expensive and have poor durability.Summary
[0005] At present, glass products with display function often have defects such as high production cost and poor durability, and are not resistant to high temperature, which is not conducive to subsequent processing and application. In order to solve the problems in the prior art, the present disclosure provides a coating composition for forming a display coating layer. The display coating layer formed from the coating composition is compatible with high temperature, has good display performance and convenient preparing procedure. The preparation and assembly process of the glass component of the present disclosure is convenient and low in cost, which is conducive to large-scale market use.
[0006] In one aspect, provided is a coating composition for forming a display coating layer, wherein, based on the total weight of the coating composition, the coating composition comprises 59-75 wt%of a glass frit powder, 0.01-0.1 wt%of scattering particles, and 24-40 wt%of a vehicle material, wherein, the glass frit powder has a refractive index of 1.45-1.55, the scattering particles comprise any one of inorganic material particles with an average particle size of 10 nm-80 nm, inorganic material particles with an average particle size of 300 nm-500 nm, metal-dielectric composite particles with a core-shell structure and an average particle size of 30 nm-100 nm or any combination thereof.
[0007] In an embodiment, the inorganic material particles comprise any one of titanium dioxide, zirconium dioxide, silicon dioxide, aluminum oxide, zinc oxide, bismuth oxide, cerium oxide and iron oxide or any combination thereof. In another embodiment, a dielectric core of the metal-dielectric composite particles with the core-shell structure comprises any one of germanium elementary substance, silicon elementary substance, germanium-silicon alloy, silicon dioxide, silicon carbide, gallium arsenide or any combination thereof. In yet another embodiment, a metal shell of the metal-dielectric composite particles with the core-shell structure comprises any one of gold, silver, platinum, iron, nickel or any combination thereof.
[0008] In an embodiment, the glass frit powder has a coefficient of thermal expansion of 6×10-6-12×10-6 K-1. In another embodiment, the glass frit powder has a coefficient of thermal expansion of 8×10-6-9×10-6 K-1. In an embodiment, the glass frit powder has a D99 particle size of 40 μm or less. In another embodiment, the glass frit powder has a D99 particle size of 20 μm or less.
[0009] In an embodiment, the vehicle material has a Brookfield viscosity of 10000-30000 cps. In another embodiment, the vehicle material comprises a resin material and a solvent, wherein the resin material comprises any one of polyvinyl polymer, polypropylene, vinyl polymer, polystyrene-based polymer, polycarbonate, cellulose, fluorine-based polymer, polyester or any combination thereof. Solvent comprises any one of α-Terpineol, butyl diglycol, (2-butoxyethoxy) ethyl acetate or any combination thereof. In another embodiment, the resin material comprises any one of polyvinyl alcohol, ethyl cellulose, polymethyl methacrylate or any combination thereof.
[0010] In an embodiment, based on the total weight of coating composition of the present disclosure, the coating composition further comprises: ≤5 wt%of an additive. In another embodiment, the additive comprises any one of a wetting dispersant, an antifoaming agent, a rheological agent, a leveling additive or any combination thereof.
[0011] In an embodiment, based on the total weight of coating composition of the present disclosure, the coating composition further comprises: 0.01-10 wt%of a fumed silica, and the fumed silica has an average agglomerated particle size of 100 nm-30 μm. In another embodiment, in the fumed silica, the weight ratio of particles with an average agglomerated particle size of 10 μm or less to all fumed silica particles is 0.01-0.1. In yet another embodiment, in the fumed silica, the weight ratio of particles with an average agglomerated particle size of 10 μm or more to all fumed silica particles is 0.01-0.1.
[0012] In another aspect, provided is a process for forming a display coating layer on a glass substrate, comprising the following steps: providing a glass substrate; applying the coating composition according to the present disclosure on a surface of the glass substrate; and subjecting the coating composition to a heat treatment to form the display coating layer.
[0013] In another aspect, provided is a display coating layer formed from the coating composition of the present disclosure.
[0014] In an embodiment, the display coating layer according to the present disclosure comprises a binder matrix and scattering particles uniformly dispersed in the binder matrix, and the scattering particles in the display coating layer have an average spacing distance of 0.78 μm or more.
[0015] In yet another aspect, provided is a glass assembly comprising the display coating layer according to the present disclosure and a glass substrate.
[0016] In an embodiment, the glass assembly according to the present disclosure is a laminated glass, and comprises the display coating layer according to the present disclosure, a first glass substrate, a second glass substrate and an intermediate interlayer, wherein the intermediate interlayer is between the first glass substrate and the second glass substrate; the display coating layer is between the first glass substrate and the intermediate interlayer, and / or the display coating layer is between the second glass substrate and the intermediate interlayer.
[0017] In yet another aspect, provided is a window assembly comprising the glass assembly according to the present disclosure. In an embodiment, the window assembly comprises a door, a window, a curtain wall, a vehicle window glass, an airplane glass or a ship glass.Brief Description of the Drawings
[0018] Figure 1 shows a schematic diagram of an embodiment of the glass assembly according to the present disclosure, wherein a display coating layer according to the present disclosure is provided on the glass substrate. The dots in the figure represent scattering particles, “d” represents the average spacing distance of the scattering particles, and the light gray area is a binder matrix, and the scattering particles are uniformly dispersed in the binder matrix.
[0019] Figure 2 shows a schematic diagram of an embodiment of the glass assembly according to the present disclosure, wherein the glass substrate used is in the form of a glass pane.
[0020] Figure 3 shows a cross-sectional diagram of an embodiment of the glass assembly according to the present disclosure.
[0021] Figure 4 shows the display function effect of an embodiment of the glass assembly according to the present disclosure.Detailed Description
[0022] General Definition and Terms
[0023] Unless otherwise stated, all publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety.
[0024] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art. If there is a contradiction, the definition provided in this application shall prevail.
[0025] Unless otherwise stated, all percentages, parts, proportions or the like are on a weight basis. It should be understood by those skilled in the art that the sum of all components in a composition may appropriately be equal to 100%. When an amount, concentration or other value or parameter is given as a range, a preferable range or a preferable upper limit and lower limit or a specific value, it should be understood that it corresponds to specifically revealing any range by combining any pair of upper limit of the range or preferable range value with the lower limit of any range or preferable range value, regardless of whether the range is specifically disclosed. Unless otherwise stated, the numerical ranges listed herein are intended to include the endpoints of the range and all integers and fractions within the range.
[0026] When used with a numerical variable, the term “about” or “approximate” usually refers to the value of the variable and all the values of the variable within the experimental error (for example, within an average 95%confidence interval) or within ±10%of the specified value, or a wider range.
[0027] The term “optional” or “optionally” means the event described subsequent thereto may or may not happen. This term encompasses the cases that the event may or may not happen, and that the contents are selected in an arbitrary manner. For example, when the content of a certain component herein is 0%-5%, it means that the component can be optionally present, that is, it encompasses the situation of absence (0%) and that of presence (>0-5%) .
[0028] The terms “include” , “comprise” , “have” , “contain” or “involve” and other variants thereof herein are meant to be inclusive or open-ended, which do not exclude other unlisted elements or process steps. It should be understood by those skilled in the art that the above terms such as “include” encompass the meaning of “consisting of” . The expression “consisting of” excludes any element, step, or ingredient not designated. The expression “substantially consisting of” means that the scope is limited to the designated elements, steps or ingredients, plus elements, steps or ingredients that are optionally present which do not substantially affect the essential and novel feature of the claimed subject matter. It should be understood that the expression “comprise” encompasses the expressions “substantially consist of” and “consist of” . The term “selected from” refers to one or more elements of the group listed thereafter, selected independently, and may encompass the combination of two or more elements.
[0029] The term “one or more” or “at least one” as used herein means one, two, three, four, five, six, seven, eight, nine or more.
[0030] The term “and / or” as used herein encompasses both “and” and “or” . A plurality of elements, components or steps defined by “and / or” means any one of the elements, components or steps and any combination thereof. For example, A and / or B encompasses A, B and A+B; A, B and / or C encompasses A, B, C, A+B, A+C, B+C and A+B+C.
[0031] Unless otherwise stated, the terms “combination thereof” , “any combination thereof” and “mixture thereof” mean multicomponent mixtures of the elements, such as two, three, four and up to the maximum possible multicomponent mixtures.
[0032] In addition, if the number of parts or components of the disclosure is not indicated before, it means that there is no limitation to the number of parts or components. Therefore, it should be interpreted as including one or at least one, and the singular word form of a part or component also includes the plural, unless the numerical value clearly indicates the singular.
[0033] Unless otherwise stated, the expressions “first” , “second” and so forth as used herein are only used to distinguish various elements, components or steps without limiting the sequence and the number, or excluding the existence of more elements, components, or steps that are not listed, such as “third” and “fourth” . Elements, components or steps defined as “first” and “second” can be the same or different.
[0034] As used herein, the meanings of “a plurality” and “multiple layers” refer to two or more, unless otherwise specifically defined. Unless the context clearly indicates, “a” and “an” can encompass singular reference as well as plural reference.
[0035] Unless otherwise specifically defined, the terms such as “installation” , “connection” and “attach” as used herein should be understood in a broad means. For example, it can be fixed connection, detachable connection or integrated; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction between two elements. For those skilled in the art, the specific meanings of the above terms herein can be understood according to the specific situation.
[0036] As used herein, the term “refractive index” has the meaning commonly understood in the art, that is, the ratio of the propagation velocity of light in vacuum to the propagation velocity of light in a medium. The refractive index can be measured by conventional methods and instruments in the art, for example, measured by a laser particle size meter or an ellipsometer.
[0037] Herein, “Dxx particle size” refers to the corresponding particle size when the cumulative particle size distribution percentage of a sample reaches xx%. The “xx” may be, for example, 10, 50, 90, 99, etc. Taking the D99 particle size as an example, its specific physical meaning is that in the sample, the particles with a particle size larger than the D99 particle size account for 1%, and the particles with a particle size smaller than the D99 particle size account for 99%. Particle sizes can be measured by conventional methods and instruments in the art, for example, measured by a laser particle size analyzer or the Brownian motion method. For samples with smaller particle size (e.g., 100 nm or less) , it can usually be measured by the Brownian motion method. For example, samples with particle sizes of more than 100 nm can be measured by a laser particle size analyzer and by standard GB / T 15445.2-2006. Herein, “average particle size” may also be referred to as “mean particle size” or “median particle size” and is also commonly referred to as “particle size D50” in the art.
[0038] Herein, “haze” refers to the percentage of transmitted light intensity that deviates from the incident light by an angle of more than 2.5° to the total transmitted light intensity. A higher haze means a reduction in the gloss and transparency of glass stacking. It can be measured by conventional methods and instruments, for example, measured by an instrument of BYK Haze-guard plus and by standard ASTM D1003 and D1044.
[0039] As used herein, “coefficient of thermal expansion” has the meaning commonly understood in the art. It may refer to the value of change in length per unit change in temperature. The coefficient of thermal expansion can be measured by conventional methods and instruments in the art, for example, measured by a thermomechanical analyzer and by standard GB / T 7991.7-2019.
[0040] Coating composition
[0041] In one aspect, provided is a coating composition for forming a display coating layer. The coating composition comprises a glass frit powder, scattering particles and a vehicle material. The coating composition may further comprise an additive and / or a fumed silica.
[0042] Glass frit powder
[0043] The glass frit powder in the coating composition of the present disclosure is a raw material suitable for forming a binder matrix. When a glass powder is subjected to a heat treatment (e.g., sintering) to form a binder matrix, the glass powder is melted to form a fusant in which scattering particles are uniformly dispersed. When cooled, the glass frit powder participates in the formation of matrix and binds tightly with the scattering particles contained therein to form a stable display coating layer. Depending on needs, a glass frit powder that can form a transparent or translucent, colored or uncolored binder matrix may be used, so as to meet the requirements for practicality, aesthetics and display function of glass products.
[0044] The glass frit powder may have a refractive index of about 1.45-1.55, such as about 1.45, about 1.48, about 1.50, about 1.52, about 1.55, etc. The refractive index should enable the coating to realize display functions to clearly present the image to be displayed. If the refractive index is too high or too low, the image edge may be blurred and brightness may be low, making it difficult to achieve a clear display performance.
[0045] The selection of coefficient of thermal expansion should be compatible with other components in the composition and other parts of the glass assembly. It is difficult to obtain a final product that meets the requirements if the coefficient of thermal expansion is too high or too low. For example, the coefficient of thermal expansion should be selected to prevent deformation or deterioration of the coating and the glass substrate in the process of sintering the coating composition to form a display coating layer. A suitable coefficient of thermal expansion will make the display coating layer have good flexibility. For example, it can prevent cracks in the display coating layer during hot bending. The coefficient of thermal expansion of a glass frit powder can be measured in the following manner: the glass frit powder is sintered into a whole to form a glass body, and the coefficient of thermal expansion (CTE) of the sintered glass body is measured by a thermomechanical analyzer and by standard GB / T 7991.7-2019. In an embodiment, the coefficient of thermal expansion (CTE) of the glass frit powder can be about 6×10-6-12×10-6 K-1, preferably about 8×10-6-9×10-6 K-1.
[0046] The particle size of the glass frit powder may affect the degree of uniform dispersion of the coating composition and the uniformity of the fusant formed during sintering. The D99 particle size of a glass frit powder can be measured by the Brownian motion method or by laser particle size analyzer. In an embodiment, the D99 particle size of the glass frit powder is about 40 μm or less, preferably about 20 μm or less. If the D99 particle size is too high, it is not conducive to a uniform dispersion of scattering particles in the fusant of a molten glass frit powder, and it is not conducive to the formation of a smooth and flat display coating layer, which may result in poor display performance. In another embodiment, the glass frit powder has a D99 particle size of about 1 μm or more, preferably about 10 μm or more.
[0047] In an embodiment, based on the total weight of the coating composition, the coating composition comprises about 59-75 wt%of a glass frit powder, for example, about 59 wt%, about 59.5 wt%, about 60 wt%, about 60.5 wt%, about 61 wt%, about 61.5 wt%, about 62 wt%, about 62.5 wt%, about 63 wt%, about 65 wt%, about 67 wt%, about 70 wt%, about 72 wt%, about 72.5 wt%, about 73 wt%, about 73.5 wt%, about 74 wt%, about 74.5 wt%, about 75 wt%, etc. If the content of a glass frit powder is too high, the content of the scattering particles in the formed display coating layer will be low, which cannot fully scatter light and result in poor display performance. If the content of the glass frit powder is too low, the spacing distance of the scattering particles in the cured display coating layer will be too small to achieve the scattering effect of a target light (e.g., a full-wavelength visible light) , which may result in a display malfunction or a decreased display performance. If the content of the glass frit powder is too low, it will not be conducive to the full binding with the scattering particles, which may create an uneven surface and affect the product performance.
[0048] Generally, the glass frit powder may contain inorganic oxides, and examples thereof include, but are not limited to, one or more of the following: Bi2O3, BaO, ZnO, Al2O3, SiO2, Na2O, K2O, etc. The proportion of each component can be adjusted according to actual needs, thereby adjusting the refractive index, sintering temperature, stability, water resistance and other properties of the glass frit powder.
[0049] Bi2O3 may be used to reduce the densification temperature and to increase the refractive index of the glass frit powder. BaO may be used as an auxiliary component in combination with Bi2O3 for increasing the refractive index. When the content of Bi2O3 is too small, the refractive index may decrease, making it difficult to achieve the target refractive index range, and leading to an increase in the sintering temperature. If the content of Bi2O3 is too high, the light absorption of the glass frit powder in the blue region will increase and the thermal stability during sintering will decrease, resulting in the deterioration of the surface of the display coating layer. As BaO is weak in reducing the densification temperature of a glass frit powder, BaO can replace part of the Bi2O3.
[0050] ZnO is a component used to reduce the densification temperature of the glass frit powder. If the content of ZnO is too high, the binder matrix formed by the glass frit powder becomes unstable, the acid resistance decreases, and the light absorption of the glass frit powder in the green region increases.
[0051] Al2O3 can be used to stabilize the glass frit powder. The content range of Al2O3 can be adjusted as needed to avoid the following: if the content is too low, the binder matrix formed by the glass frit powder becomes unstable and the chemical resistance decreases; if the content is too high, the refractive index of the glass frit powder decreases and the sintering temperature increases.
[0052] SiO2 is a component used to stabilize the glass frit powder phase. When the content of SiO2 is too low, the binder matrix formed by the glass frit powder becomes unstable. When the content of SiO2 is too high, the refractive index of the glass frit powder decreases and the sintering temperature increases.
[0053] B2O3 is used to reduce the coefficient of thermal expansion, lower the densification temperature, and stabilize the binder matrix formed by glass frit powder. When the content of B2O3 is too low, the binder matrix formed by the glass frit powder becomes unstable. When the content of B2O3 is too high, the water resistance of the display coating layer decreases.
[0054] Alkali metal oxides, such as Na2O and K2O, are components used to reduce the densification temperature of the glass frit powder. When the content of Na2O or K2O is too low, the sintering temperature increases. If the content of Na2O or K2O is too high, the chemical resistance of the binder matrix formed by the glass frit powder will decrease. The glass frit powder may contain an inevitable small amount of TiO2 or ZrO2 but not more, for example, no more than 5%, preferably no more than 3%, and more preferably no more than 1%, based on the total weight of the glass frit powder.
[0055] Preferably, the glass frit powder used in the present disclosure does not contain any transition metal, e.g., Fe, V, Cr, Mn, Ni, Co, Cu, Pd, Ag, Au, Pt, Cd, etc. Transition metals show strong absorption characteristics in a specific light wavelength range, and the light absorption of transition elements may cause significant light loss. In this regard, it is necessary to avoid adding transition elements to the composition of the glass frit powder. However, it may optionally contain a small amount of Ce, because the oxide of Ce (which is a lanthanide) is limited to the dark blue region in the light absorption characteristics, and the Ce oxide helps to fully burn out the organic matter therein during the preparation of the display coating layer.
[0056] Scattering particles
[0057] Scattering particles are those of a certain size, through which light is scattered when the light enters the display coating layer, whereby achieving a visual display effect.
[0058] The light scattering process can be achieved by the Rayleigh Scattering, the Mie Scattering and the Localized Surface Plasma Resonance (LSPR) Scattering. Each scattering process is realized based on the composition and size of the scattering particles.
[0059] The scattering particles should have good thermal stability, e.g., that at 600℃ or higher, so as to withstand the sintering process of the coating.
[0060] The size of the scattering particles is usually in the nanometer scale, for example, several nanometers to hundreds of nanometers, or smaller or larger. The average particle size of the scattering particles can be measured by the Brownian motion method or by a laser particle size analyzer. In an embodiment, the scattering particles include, but are not limited to, any one of the following materials or any combination thereof: inorganic material particles with an average particle size of about 10 nm-80 nm, inorganic material particles with an average particle size of about 300 nm-500 nm, metal-dielectric composite particles with a core-shell structure and an average particle size of about 30 nm-100 nm. In a preferable embodiment, the scattering particles comprise the metal-dielectric composite particles with a core-shell structure and a particle size of 30 nm-100 nm. When a combination of more than one material is used, the different scattering principles may work together to achieve the final scattering effect.
[0061] Inorganic material particles with an average particle size of about 10 nm-80 nm may typically be used to realize a Rayleigh Scattering process, such as inorganic material particles with an average particle size of about 10 nm, about 20 nm, about 40 nm, about 60 nm, about 80 nm, etc. Inorganic material particles with an average particle size of about 300 nm-500 nm may typically be used to realize a Mie Scattering process, such as inorganic material particles with an average particle size of about 300 nm, about 350 nm, about 400 nm, about 450 nm, about 500 nm, etc., preferably about 400 nm. In an embodiment, the inorganic oxides can be used as scattering particles, examples include, but are not limited to, titanium dioxide (TiO2) and / or zirconium dioxide (ZrO2) .
[0062] The realization of a Plasmon Resonance Scattering can usually be accomplished by metal-dielectric composite particles with a core-shell structure and an average particle size of about 30 nm-100 nm, such as the metal-dielectric composite particles with an average particle size of about 30 nm, about 50 nm, about 70 nm, about 90 nm, about 100 nm, etc. Each metal-dielectric composite particle comprises a dielectric core and a metal shell. Generally, the dielectric core may include, but is not limited to, one or more of the following: germanium elementary substance (Ge) , silicon elementary substance (Si) , germanium-silicon alloy (Ge-Si) , silicon dioxide (SiO2) , silicon carbide (SiC) and gallium arsenide (GaAs) . The metal shell includes, but is not limited to, one or more of gold (Au) , silver (Ag) , platinum (Pt) , iron (Fe) and nickel (Ni) . Preferably, the metal-dielectric composite particles include, but are not limited to, one or more of the following: silver-silica dioxide composite particles, platinum-silica dioxide composite particles, and silver-silicon carbide composite particles.
[0063] In an embodiment, based on the total weight of the coating composition, the coating composition comprises about 0.01-0.1 wt%of scattering particles, for example, about 0.01 wt%, about 0.02 wt%, about 0.03 wt%, about 0.04 wt%, about 0.05 wt%, about 0.06 wt%, about 0.07 wt%, about 0.08 wt%, about 0.09 wt%, about 0.01 wt%, etc. A suitable content of scattering particles is helpful to achieve good scattering effect and render the products with excellent display performance. It is difficult to achieve excellent display performance if the content of the scattering particles is too high or too low. If the content of the scattering particles is too low, a light cannot be fully scattered, and the display performance may be poor or impossible to achieve. If the content of the scattering particles is too high, the spacing distance of the scattering particles in the cured display coating layer will be too small to achieve the scattering effect of a target light (e.g., a full-wavelength visible light) , and the display function cannot be realized, or the display performance will be degraded. In addition, if the content of the scattering particles is too high, the haze of the display coating layer and related products (such as a glass assembly) containing the display coating layer will increase and the user experience will become worse.
[0064] Vehicle material
[0065] As a dispersing phase, the vehicle material effectively disperses the components in the coating composition, forming a coating composition slurry. The vehicle material can adjust the viscosity and fluidity of the coating composition (slurry) . The viscosity and fluidity of the coating composition (slurry) may affect the optical performance and display performance of the display coating layer. The vehicle material may be a liquid vehicle, which provides the coating composition with good dispersity and suitable fluidity, which is advantageous for application and processing.
[0066] In an embodiment, the vehicle material has a Brookfield viscosity of about 10000-30000 cps, for example, about 10000 cps, about 15000 cps, about 20000 cps, about 25000 cps, about 30000 cps. The Brookfield viscosity can be measured by a Brookfield viscometer at a rotation speed of 150 rpm. If the viscosity of the vehicle material is too high, this may lead to a coating composition with high viscosity and poor fluidity. An uneven coating may occur during the coating process, leading to a reduction in the thickness uniformity and an increase in the surface roughness of the coating obtained, which may adversely affect the optical properties of glass products (e.g., increased haze) . If a coating composition is applied on the surface of a substrate (e.g., a glass substrate) where the viscosity of the vehicle material is too low, the resulting wet coating layer may not maintain a stable shape and thickness. In addition, it is difficult to maintain the shape and thickness of the coating layer during the drying process of said wet coating layer, and this may affect the flatness of the display coating layer, which may result in a display malfunction or a decreased display performance.
[0067] The vehicle material generally comprises a resin material and a solvent. Suitable resin materials and solvents can be used to impart appropriate viscosity and fluidity to the vehicle material.
[0068] The resin material provides the viscosity, fluidity, etc. required by the vehicle material. Available resin materials include, but are not limited to, one or more of the following: polyvinyl polymer (e.g., polyethylene (PE) , ethylene-vinyl acetate copolymer (EVA) ) , polypropylenes (PP) , vinyl polymer (e.g., polyvinyl chloride (PVC) , polyvinyl butyral (PVB) , polyvinyl alcohol (PVA) , polyvinylidene chloride (PVDC) , polyvinyl acetate (PVAC) ) , polystyrene-based polymer (polystyrene (PS) , styrene-acrylonitrile copolymer (AS) ) , acrylic-based polymer (e.g., polymethyl methacrylate (PMMA) ) , polycarbonate (PC) , cellulose (e.g., ethyl cellulose (EC) , cellulose acetate (CA) , propyl cellulose (CP) , cellulose acetate butyrate (CAB) ) , and fluorine-based polymer (polychlorofluoroethylene (PCTFE) , polytetrafluoroethylene (PTFE) ) , polyester (e.g., polyethylene terephthalate (PET) , polybutylene terephthalate (PBT) ) , etc. In a preferable embodiment, the resin material comprises one or more of the following: polyvinyl alcohol, ethyl cellulose, polymethyl methacrylate. By adjusting the molecular weight of the resin material, the vehicle material can be given the appropriate viscosity and fluidity. For example, if the resin material is ethyl cellulose, ethyl cellulose with different molecular weight distributions and viscosities can be selected as needed to impart the vehicle material with suitable viscosity and fluidity, and further improve the performance of the display coating layer. For example, the brand of ethyl cellulose used may include, but not limited to, one or more of the following: EthocelTM Std 4 Premium, EthocelTM Std 14 Premium, EthocelTM Std 45 Premium, etc.
[0069] The solvent in the vehicle material, which provides suitable fluidity, allows the coating composition to be uniformly applied to the surface to be coated and the solid particles (e.g., glass frit powder, scattering particles, etc. ) of the coating composition to be uniformly dispersed. Preferably, in the present disclosure, a solvent with a high boiling point may be used to avoid rapid volatilization of the liquid phase during the process of preparing the display coating layer (e.g., during the process of applying the coating composition to the glass substrate) , so as to avoid unevenness or other defects in the coating. A solvent with a boiling point of 200℃ or higher may be used as needed. In an embodiment, the solvent in the vehicle material includes, but is not limited to, one or more of the following: α-Terpineol, butyl diglycol, (2-butoxyethoxy) ethyl acetate.
[0070] In an embodiment, based on the total weight of the coating composition, the coating composition comprises about 24-40 wt%of a vehicle material, for example, about 24 wt%, about 24.5 wt%, about 25 wt%, about 25.5 wt%, about 26 wt%, about 26.5 wt%, about 27 wt%, about 28 wt%, about 29 wt%, about 30 wt%, about 32 wt%, about 33.5 wt%, about 34 wt%, about 34.5 wt%, about 35 wt%, about 35.5 wt%, about 36 wt%, about 36.5 wt%, about 37 wt%, about 37.5 wt%, about 38 wt%, about 38.5 wt%, about 39 wt%, about 39.5 wt%, about 40 wt%, etc. The vehicle material with a too high or too low content is not conducive to giving the coating composition suitable dispersity and fluidity and is not conducive to forming a flat display coating layer with excellent display performance.
[0071] Adjusting the ratio of the resin material to the solvent helps to provide the coating composition with good dispersity and suitable fluidity, which is beneficial for application and processing. In an embodiment, the weight ratio of the resin material to the solvent is about 1: 10-1: 40, for example, about 1: 10, about 1: 15, about 1: 20, about 1: 24, about 1: 25, about 1: 30, about 1: 35, about 1: 40.
[0072] Additive
[0073] The coating composition according to the present disclosure may further comprise an additive which can adjust the fluid properties of the coating composition and improve the dispersion uniformity of the coating composition. Useful examples of the additive in the present disclosure include, but are not limited to, a wetting dispersant, an antifoaming agent, a rheological agent, a leveling additive, etc.
[0074] The wetting dispersant can reduce the interfacial tension between the coating composition and the surface to be coated, reducing the contact angle and improving the wetting effect. It is helpful for the coating composition to adhere quickly and evenly to the surface to be coated during the coating process. The particles in the coating composition can be uniformly dispersed to form a homogeneous liquid with the aid of the wetting dispersant, which helps to improve the display performance of the display coating layer. Examples of suitable wetting agents include, but are not limited to, one or more of the following: sulfate, alkyl quaternary ammonium salt, lecithin, polyethylene glycol, polyol, polyurethane, modified polyacrylate, etc. An alkyl hydroxyammonium salt of a block copolymer containing an acidic group is preferably used.
[0075] The leveling additive improves the leveling property of the coating composition to avoid surface defects such as cavity shrinkages, edge shrinkages, brush marks, roller marks, etc. in the coating layer after coating. Examples of suitable leveling additives include, but are not limited to, one or more of the following: polydimethylsiloxane, polymethylphenylsiloxane, polyether-modified silicone, fluorine-based surfactant, polyacrylate, etc.
[0076] The antifoaming agent helps to inhibit or eliminate the foam in a coating composition and improve the surface properties (e.g., appearance, flatness, etc. ) of the coating layer. Examples of suitable leveling additives include mineral oil antifoaming agents, silicone antifoaming agents, etc.
[0077] During the process of preparation, application and curing of the coating composition, rheological problems may occur which may affect properties such as mixing, sedimentation, stability, vertical flow, etc. The addition of the rheological agent is helpful in adjusting the rheological properties of the coating composition so that during the preparation and application, the properties of the coating composition (e.g., viscosity recovery, etc. ) can be adjusted to obtain a flat and uniform display coating layer. Examples of suitable leveling additives include, but are not limited to, cellulose, xanthan gum, polyacrylate, polyurethane, etc.
[0078] The coating composition may be free of any additive. Alternatively, an appropriate amount of the additive can be added as needed to improve the properties (e.g., rheology, viscosity, etc. ) of the coating composition, thereby improving the surface properties (e.g., flatness) of the display coating layer. In an embodiment, based on the total weight of the coating composition, the coating composition comprises about ≤5 wt%of an additive, for example, about 0.01 wt%, about 0.5 wt%, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 4.5 wt%, about 5%wt%, etc.
[0079] Fumed silica
[0080] A fumed silica can be used to regulate the viscosity of the coating melt formed during the preparation process and also as a spacer to prevent the adhesion between the glasses during the processing. If needed, a fumed silica can be added to achieve anti-adhesion and viscosity-increasing effects.
[0081] The coating composition may be free of fumed silica. Alternatively, the coating composition may comprise a fumed silica as needed. In an embodiment, based on the total weight of the coating composition, the coating composition may comprise about 0.01-10 wt%of a fumed silica, for example, about 0.01 wt%, about 0.5 wt%, about 1 wt%, about 1.5 wt%, about 2 wt%, about 4 wt%, about 5 wt%, about 7 wt%, about 8 wt%, about 8.5 wt%, about 9 wt%, about 9.5 wt%, about 10 wt%, etc. If the content of the fumed silica is too high or too low, it is not conducive to the uniformity and flatness of the display coating layer, and may adversely affect the user experience.
[0082] A fumed silica with a nanometer-scale primary particle size (e.g., fumed silica with a primary particle size of 1-100 nm) can be used. After the agglomeration of fumed silica particles, agglomerated particles are formed. The fumed silica may have an average agglomerated particle size of about 100 nm-30 μm, for example, about 100 nm, about 200 nm, about 300 nm, about 500 nm, about 1 μm, about 5 μm, about 10 μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, etc. The average agglomerated particle size of the fumed silica can be measured by a laser particle size analyzer and by standard GB / T 15445.2-2006. In an embodiment, in the fumed silica, the weight ratio of particles with an average agglomerated particle size of 10 μm or less to all fumed silica particles is about 0.01-0.1, for example, about 0.01, about 0.02, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09, about 0.1, etc. The fumed silica particles with smaller sizes can increase the viscosity of the coating fusant and reduce the fluidity of the coating fusant during the single hot bending process, weakening or preventing the coating fusant flow due to external effects (e.g., gravity) and avoiding the uneven thickness of the cured display coating layer. The smaller sizes also contribute to the uniform dispersion of scattering particles in the coating layer, avoiding the uneven distribution of the scattering particles due to their deposition caused by gravity and other factors. In another embodiment, in the fumed silica, the weight ratio of particles with an average agglomerated particle size of 10 μm or more to all fumed silica particles is about 0.01-0.1, for example, about 0.01, about 0.02, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09, about 0.1, etc. In the process of double-sheet hot bending, fumed silica particles with large sizes can be used as spacers to prevent the coating fusant from sticking to another piece of glass.
[0083] Display coating layer
[0084] The coating composition according to the present disclosure can be used for forming a display coating layer, e.g., forming a display coating layer on a glass substrate of a glass assembly, to realize a display function. Therefore, in another aspect, provided is also a display coating layer formed from the coating composition according to the present disclosure.
[0085] After the coating composition has been applied to the surface of a substrate (e.g., a glass substrate) , a heat treatment is carried out to dry and sinter the coating composition, thereby removing the organic matter in the coating composition and forming a cured display coating layer. The resulting cured display coating layer may comprise or only comprise inorganic components, that is, a binder matrix and scattering particles uniformly dispersed in the binder matrix (e.g., as shown in Fig. 2) .
[0086] The binder matrix can be formed by sintering the glass frit powder. If a fumed silica is added, it can form a binder matrix together with the glass frit powder after sintering. In order to realize the display function of the display coating layer and to achieve both practicality and aesthetics, the binder matrix may be transparent or translucent.
[0087] The used scattering particles (as described above) have good thermal stability, and the structural composition before and after sintering remains stable and uniformly dispersed in the bonder matrix. The uniform distribution of the scattering particles is helpful in realizing a fine image display function. The average spacing distance of scattering particles can be adjusted in accordance with the wavelength of the light to be scattered. The average spacing distance of the scattering particles should be greater than the wavelength of the target light in order to achieve the scattering of the light above the target wavelength. The scattering particles in the display coating layer may have an average spacing distance of 0.78 μm or more to achieve the scattering effect of a full-wavelength visible light, for example, about 0.8 μm or more, about 0.85 μm or more, about 0.9 μm or more, or about 1 μm or more. The average spacing distance of scattering particles in the display coating may be influenced by the components in the coating composition, for example, types, properties (e.g., viscosity) , contents of the components, etc.
[0088] Generally, the display coating layer with a certain thickness will improve the performance of the display function. For example, a display coating layer containing the LSPR scattering particles may typically have a thickness of at least about 5 μm, even at least about 10 μm, even at least about 50 μm, typically at most about 200 μm or at most about 300 μm, for example, about 9.3 μm. The shape of the display coating layer is not particularly limited, and it may completely or partially cover the surface of the substrate to impart display functions to a target area.
[0089] The visualization effect of the display coating layer can be achieved by projecting the image directly onto the display coating layer. The visualization effect can also be achieved by means of optical waveguide technology, for example, after the imaging process has completed by an optical machine, the light is coupled into the glass substrate through an optical waveguide, which transmits the light to a target area of the display coating layer by the principle of total reflection and then releases the light by scattering.
[0090] Preparation process
[0091] Further provided is a process for forming a display coating layer on a glass substrate, which includes providing a glass substrate, applying a coating composition of the present disclosure on a surface of the glass substrate; and subjecting the coating composition to a heat treatment to form a display coating layer.
[0092] Glass substrates commonly used in the art can be used. Examples include those described below.
[0093] There is no particular limitation herein as to the manner in which the coating composition is applied and common manners in the art can be used, for example, wet coating methods such as, but not limited to, slot die coating, curtain coating, screen printing, tape casting method and so forth. The coating composition can be applied on whole or part of a surface of the glass substrate, as needed, to meet the display needs of a specific area.
[0094] The organic materials (e.g., the vehicle material and the additive) in the coating composition can be removed by heat treatment, allowing the glass frit powder to form a binder matrix which covers a surface of the glass substrate. The formation of a binder matrix allows the scattering particles to be uniformly dispersed in the binder matrix. As described above, the uniform distribution of scattering particles is helpful to realize the fine image display function. The manners of a heat treatment may include, but are not limited to, drying, sintering or the combination thereof. Dry can be carried by infrared drying, microwave drying, hot air drying and air knife drying and so forth. After drying, the coating composition can be sintered to allow the glass frit powder form a fusant after melting, so that the scattering particles can be uniformly dispersed in the fusant. The manners in which the heat treatment is carried out are well known to those skilled in the art and can be adjusted according to the specific materials used.
[0095] It is also possible to subject the glass substrate to treatments such as heat bending, tempering, etc. to meet the requirements of the application, e.g., to form a desired shape or curvature. The above operations may be carried out simultaneously or after the heat treatment. In an embodiment, the above operation is performed simultaneously with the heat treatment or when the heat treatment has been completed but the temperature of the system has not yet dropped significantly.
[0096] Glass assembly and window assembly
[0097] In another aspect, provided is a glass assembly comprising the display coating layer according to the present disclosure. The display coating layer is usually on a surface of a component (such as a glass substrate) in a glass assembly. Therefore, the glass assembly according to the present disclosure may comprise a display coating layer and a glass substrate (e.g., a glass pane) . The display coating layer can be on all or part of a surface of the glass substrate, as needed, to impart a display function to a target area. The display coating layers at different positions in the glass assembly can be the same or different, depending on the need, to meet different display function requirements.
[0098] An embodiment of the glass assembly according to the present disclosure is shown, for example, in Figure 2. The display coating layer is on a surface of the glass substrate. The black dots represent scattering particles, “d” represents the average spacing distance of the scattering particles, and the light gray area is a binder matrix. The scattering particles are uniformly dispersed in the binder matrix.
[0099] In an embodiment, the glass assembly is a laminated glass and comprises the display coating layer, a first glass substrate, a second glass substrate and an intermediate interlayer. In terms of positional relationship, the intermediate interlayer is between the first glass substrate and the second glass substrate. The display coating layer may be between the first glass substrate and the intermediate interlayer, or between the second glass substrate and the intermediate interlayer, or between the first glass substrate and the intermediate interlayer and between the second glass substrate and the intermediate interlayer at the same time.
[0100] An embodiment of the laminated glass of the present disclosure is shown, for example, in Figure 3. The first and second glass substrates are both glass panes and the interlayer is between the first glass pane and the second glass pane. The display coating layer is between the second glass pane and the intermediate interlayer.
[0101] Glass substrate may be an amorphous inorganic nonmetallic material, which is generally made of a variety of inorganic minerals (e.g., quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda ash, etc. ) as the main raw materials, and a small amount of auxiliary raw materials are added. Its main components are silicon dioxide and other oxides. “Glass” may be any type of glass, for example ordinary glass, whose chemical composition comprises Na2SiO3, CaSiO3, SiO2 or Na2O·CaO·6SiO2, etc., such as silicate double salt, which is an amorphous solid with irregular structure. For example, glass can be colorless glass and it can also be colored glass into which certain metals oxides or salts are mixed to exhibit colors, or tempered glass obtained by a physical or chemical method and so forth. In addition, the structure of “glass” itself is not particularly limited, and it can be single-layer glass or multi-layer glass, or other types of glass, such as insulating glass and so forth. The glass substrate may be a glass pane. The shape of the glass pane can be arbitrary. According to the actual needs, examples of glass panes are square, rectangular, round, oval, regular hexagon and so on. As used herein, according to the actual needs, the surface of the glass pane can be horizontal and flat, or with a radian, or with an irregular radian. Those skilled in the art can also adjust the thickness of the glass pane according to actual needs. In the glass assembly according to the present disclosure, when there is more than one glass pane, the materials, shapes, textures and so forth may be the same or different.
[0102] The intermediate interlayer counteracts the roughness of surface of the display coating layer to improve the optical properties of the laminated glass as a whole, for example, to reduce the haze. The intermediate interlayer may be of a certain viscosity, which gives itself a certain adhesive force with the adjacent layers to form a strong laminated glass. Examples of the intermediate interlayer include, but are not limited to, polyvinyl butyral (PVB) , ethylene-vinyl acetate copolymer (EVA) , thermoplastic polyolefin (TPO) , polyolefin elastomer (POE) , polyethylene terephthalate (PET) , polyvinyl chloride (PVC) , etc. PVB is preferred, and PVB with a refractive index of about 1.49 is particularly preferred.
[0103] The thickness of the intermediate interlayer facilitates the stability of the glass assembly, effectively filling the space between the edge of the display coating layer and the edge of the adjacent layer and preventing possible damage to the glass pane when a pressure is applied to the glass pane during the manufacture of the laminated glass. Therefore, in an embodiment, the thickness of the intermediate interlayer may be about 0.1-0.8 mm. Dyes may also be added to the intermediate interlayer to change its light transmittance, so as to further optimize or provide better overall display performance.
[0104] In a further aspect, also provided is a window assembly comprising the glass assembly according to the present disclosure.
[0105] In an embodiment, the window assembly comprises a door, a window, a curtain wall, a vehicle window glass, an airplane glass or a ship glass.
[0106] It should be understood that the embodiments shown in the figures herein only illustrate the optional architecture, shape, size and arrangement of various optional components in the glass stacking and the window assembly according to the present disclosure, but are merely illustrative and not restrictive, and other shapes, sizes and arrangements may be adopted without departing from the spirit and scope of the present disclosure.
[0107] Beneficial effects
[0108] In the disclosure, the display coating layer formed from the coating composition, which has good display performances, is compatible with high-temperature heat treatment and the processing process thereof is simple and convenient. The glass assembly comprising the display coating layer according to the present disclosure has a low production cost, good display performances, easy processing and good market application prospect.
[0109] Examples
[0110] A further detailed description of the scheme of the present disclosure in conjunction with specific examples is provided as follows.
[0111] It should be noted that the following examples are only examples for clearly explaining the technical scheme of the present disclosure and are not limitations of the present disclosure. For an ordinary technical person in the art, other changes or modifications in different forms can be made on the basis of the above description, and it is unnecessary and impossible to exhaust all the embodiments herein and the obvious changes or modifications derived therefrom are still within the protection scope of the present disclosure. Unless otherwise specified, the instruments, equipments and reagent materials used herein are commercially available.
[0112] Materials, instruments and test methods
[0113] Glass substrate: glass pane, brand: PLC glass, purchased from Saint-Gobain glass Qingdao factory.
[0114] Glass frit powder: with a refractive index n of 1.52, a coefficient of thermal expansion of 8.3×10-6 K-1, and a D99 particle size of < 20 μm, main components: SiO2, B2O3, ZnO, Na2O, K2O and Al2O3, supplied by Japan TOMATEC CO., LTD.
[0115] Scattering particles: LSPR scattering particles, which are mix particles of brands Luxlab OM and Luxlab MA, purchased from Luxlab Company.
[0116] Vehicle material:
[0117] Ethyl cellulose, brand: EthocelTM Std 45 Premium, purchased from DOW Chemical Company;
[0118] Butyl diglycol, purchased from Sinopharm Reagent Company.
[0119] Additive: wetting dispersant, brand BYK180, purchased from BYK Company.
[0120] Haze: the equipment of BYK Haze-guard plus is used and the equipment standards are ASTM D1003 and D1044.
[0121] Preparation and performance
[0122] Example 1:
[0123] The components were weighed according to Table 1. The glass frit powder, the scattering particles, the vehicle material and the additive were subjected into a mechanical stirrer to mix thoroughly and then ground by a three-roll grinding machine to obtain a coating composition slurry. The coating composition slurry was uniformly coated on the surface of the glass pane by tape casting before being transferred to an oven to be dried at 150℃ for 10 min and heated to 650℃ for 5 min for a heat treatment, which sintered the coating composition slurry to form a display coating layer on the glass pane.
[0124] The glass pane with the display coating layer, PVB and another glass pane were sequentially laminated and then pressed to obtain the glass assembly of Example 1 (the specific structure is shown in Figure 2) .
[0125] Example 2:
[0126] In accordance with Table 1, the glass assembly of Example 2 was obtained with the reference to the preparation process of Example 1.
[0127] The hazes of Examples 1 and 2 were tested, and the test results are shown in Table 1.
[0128] Table 1
[0129] In Table 1, the content of each component in the coating composition is calculated based on the total weight of the coating composition. The additive content is approximately 1 wt%and makes the sum of the content of each component in the coating composition 100%.
[0130] The cross-sectional diagram of laminated glass in Example 1 is shown in Figure 3. The display coating layer was closely combined with the first glass pane, and the display coating layer had a flat surface with a thickness of about 9.3 μm. Figure 4 shows the display function effect of laminated glass in Example 1, having clear and beautiful images and excellent user experience. The laminated glass of Example 2 also had good product appearance and display function. The hazes of laminated the glass in Examples 1 and 2 can both meet the use requirements well.
[0131] Although the specific embodiments of the present disclosure have been described above, it should be understood by those skilled in the art that this is by way of example only and the protection scope of the present disclosure is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principle and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.
Claims
1.A coating composition for forming a display coating layer, wherein,based on the total weight of the coating composition, the coating composition comprises:59-75 wt%of a glass frit powder,0.01-0.1 wt%of scattering particles, and24-40 wt%of a vehicle material,wherein,the glass frit powder has a refractive index of 1.45-1.55,the scattering particles comprise any one of inorganic material particles with an average particle size of 10 nm-80 nm, inorganic material particles with an average particle size of 300 nm-500 nm, metal-dielectric composite particles with a core-shell structure and an average particle size of 30 nm-100 nm, or any combination thereof.2.The coating composition according to claim 1, characterized in that,the inorganic material particles comprise any one of titanium dioxide, zirconium dioxide, silicon dioxide, aluminum oxide, zinc oxide, bismuth oxide, cerium oxide, iron oxide or any combination thereof; and / ora dielectric core of the metal-dielectric composite particles with the core-shell structure comprises any one of germanium elementary substance, silicon elementary substance, germanium-silicon alloy, silicon dioxide, silicon carbide, gallium arsenide or any combination thereof; and / ora metal shell of the metal-dielectric composite particles with the core-shell structure comprises any one of gold, silver, platinum, iron, nickel or any combination thereof.3.The coating composition according to claim 1, characterized in that,the glass frit powder has a coefficient of thermal expansion of 6×10-6-12×10-6 K-1; and / orthe glass frit powder has a D99 particle size of 40 μm or less.4.The coating composition according to claim 1, characterized in that,the glass frit powder has a coefficient of thermal expansion of 8×10-6-9×10-6 K-1; and / orthe glass frit powder has a D99 particle size of 20 μm or less.5.The coating composition according to claim 1, characterized in that,the vehicle material has a Brookfield viscosity of 10000-30000 cps; and / orthe vehicle material comprises a resin material and a solvent, wherein,the resin material comprises any one of polyvinyl polymer, polypropylene, vinyl polymer, polystyrene-based polymer, polycarbonate, cellulose, fluorine-based polymer, polyester or any combination thereof,the solvent comprises any one of α-Terpineol, butyl diglycol, (2-butoxyethoxy) ethyl acetate or any combination thereof.6.The coating composition according to claim 5, characterized in that,the resin material comprises any one of polyvinyl alcohol, ethyl cellulose, polymethyl methacrylate or any combination thereof.7.The coating composition according to any one of claims 1-6, characterized in that,based on the total weight of the coating composition, the coating composition further comprises: ≤ 5 wt%of an additive; and / orthe additive comprises any one of a wetting dispersant, an antifoaming agent, a rheological agent, a leveling additive or any combination thereof.8.The coating composition according to any one of claims 1-6, characterized in that,based on the total weight of the coating composition, the coating composition further comprises: 0.01-10 wt%of a fumed silica, and the fumed silica has an average agglomerated particle size of 100 nm-30 μm.9.The coating composition according to claim 8, characterized in that,in the fumed silica, the weight ratio of particles with an average agglomerated particle size of 10 μm or less to all fumed silica particles is 0.01-0.1; and / orin the fumed silica, the weight ratio of particles with an average agglomerated particle size of 10 μm or more to all fumed silica particles is 0.01-0.1.10.A process for forming a display coating layer on a glass substrate, comprising the following steps:providing a glass substrate;applying the coating composition according to any one of claims 1 to 9 on a surface of the glass substrate; andsubjecting the coating composition to a heat treatment to form the display coating layer.11.A display coating layer formed from the coating composition according to any one of claims 1-9.12.The display coating layer according to claim 11, characterized in that,the display coating layer comprises a binder matrix and scattering particles uniformly dispersed in the binder matrix;the scattering particles in the display coating layer have an average spacing distance of 0.78 μm or more.13.A glass assembly comprising the display coating layer according to claim 11 or 12 and a glass substrate.14.The glass assembly according to claim 13, characterized in that,the glass assembly is a laminated glass and comprises the display coating layer, a first glass substrate, a second glass substrate and an intermediate interlayer,wherein,the intermediate interlayer is between the first glass substrate and the second glass substrate;the display coating layer is between the first glass substrate and the intermediate interlayer, and / orthe display coating layer is between the second glass substrate and the intermediate interlayer.15.A window assembly comprising the glass assembly according to claim 13 or 14.16.The window assembly according to claim 15, characterized in that,the window assembly comprises a door, a window, a curtain wall, a vehicle window glass, an airplane glass or a ship glass.