Low wetting angle glass substrate, preparation method and display panel

Abstract

The present invention relates to the technical field of glass substrate preparation, and in particular to a low wetting angle glass substrate, a preparation method and a display panel. The raw material components include 68.5% to 72% SiO in molar percentage. 2 , 9.8%~12.5%Al 2 O 3 , 0.73% to 5% B 2 O 3 , 4% to 6% MgO, 4% to 6% CaO, 0.5% to 2% SrO, 1.6% to 5% BaO and 0.1% to 0.2% K 2 O, by adding an appropriate amount of K 2 O, while ensuring the performance of the glass substrate, increasing the wettability of the glass liquid, fully infiltrating the surface of the overflow brick, reducing the friction between the glass liquid and the surface of the overflow brick, reducing the wear of the overflow brick, ensuring the dimensional stability of the overflow brick, making the amount of glass liquid flowing out between the far and near ends of the overflow brick equal, improving the uniformity of the thickness of the glass plate, ensuring the quality of the product, ensuring the service life of the overflow brick, and thus reducing the production cost. Solve the problem of poor uniformity of the thickness of the glass substrate and high production cost caused by the wear and poor dimensional stability of the overflow brick.

Description

Technical Field

[0001] The present invention relates to the technical field of glass substrate preparation, and in particular to a low wetting angle glass substrate, a preparation method and a display panel. Background Art

[0002] Currently, liquid crystal display technology has been widely used in a variety of products such as mobile phones, computers, and televisions. However, since it uses the LED backlight behind it as a light source, the liquid crystal display technology has viewing angle limitations, and has disadvantages in color, flexible screen, and thinness. OLED displays have the characteristics of self-luminescence, higher energy utilization, better picture quality, lighter and thinner products, and lower costs. Therefore, this technology is becoming more and more mainstream in the market.

[0003] Low-temperature polysilicon thin-film transistors (LTPS TFTs) can be used to manufacture smaller and faster transistors due to their high electron mobility characteristics, and have the advantages of high brightness, high resolution and low power consumption. Therefore, LTPS-OLED technology can meet the requirements of traditional hard-screen high-resolution displays as well as the requirements of flexible high-resolution displays.

[0004] However, whether it is the traditional hard-screen LTPS-OLED display or the flexible OLED screen, LTPS and OLED need to be produced on a glass substrate. The corresponding preparation process requires that the glass substrate must have high Young's modulus, low dimensional deformation, low thickness change and other performance requirements.

[0005] The substrate glass currently used for LTPS and OLED displays has high thermal stability, which results in the production process temperature of the glass being 50 to 100°C higher than that of ordinary TFT LCD glass, exacerbating the thermal creep of the overflow brick (zircon material), thus causing uneven thickness of the glass plate. In order to make the thickness of the glass plate controllable and easy to control, the overflow brick needs to be "wetted" after the production line is ignited and heated up. The purpose is to completely wrap the surface of the overflow brick with glass liquid, reduce the friction between the overflowed glass liquid and the surface of the overflow brick during the glass production process, and make the glass liquid only rub against the glass liquid during the pull-down process, and the friction between the same material is minimized. The glass is almost pulled down by its own weight, which is more conducive to the control of the thickness of the glass plate. At the same time, it also reduces the friction between the glass liquid and the surface of the overflow brick when the overflow is pulled down, reduces wear, ensures the dimensional stability of the overflow brick and the equal amount of glass liquid flowing between the far and near ends of the overflow brick, increases the thickness uniformity of the glass plate, and ensures that the glass plate has a low thickness variation.

[0006] However, the traditional technical means to increase the complete "wetting" of the glass liquid and the overflow brick is to increase the temperature to reduce the viscosity of the glass liquid, thereby reducing the wetting angle between the glass liquid and the overflow brick, or repeatedly change the position and inclination angle of the overflow brick so that the surface of the overflow brick is completely "wetted" by the glass liquid. These two methods will aggravate the thermal creep of the overflow brick, reduce the dimensional stability of the overflow brick, make the flow of the glass liquid overflowing from the overflow brick groove unstable, and greatly reduce the service life of the overflow brick, reduce the thickness uniformity of the glass plate, and increase the production cost. Summary of the invention

[0007] Aiming at the problems in the prior art of overflow brick wear and poor dimensional stability of overflow bricks, resulting in poor thickness uniformity of glass substrates and high production costs, the present invention provides a low wetting angle glass substrate.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The present invention provides a low wetting angle glass substrate, which comprises the following raw material components in terms of mole percentage:

[0010] SiO2 is 68.5% to 72%, Al2O3 is 9.8% to 12.5%, B2O3 is 0.73% to 5%, MgO is 4% to 6%, CaO is 4% to 6%, SrO is 0.5% to 2%, BaO is 1.6% to 5% and K2O is 0.1% to 0.2%.

[0011] Preferably, in terms of molar percentage, 0.9SiO2+0.5Al2O3+0.65B2O3+0.1MgO+2CaO+0.5SrO+0.5BaO+0.1K2O>0.83.

[0012] Preferably, the alkaline earth metal oxide RO in the raw material components is less than 16%, and the RO includes MgO, CaO, SrO and BaO.

[0013] A method for preparing the low wetting angle glass substrate as described above comprises the following steps:

[0014] Weigh the raw material components by mole percentage, mix them evenly, and form a mixture;

[0015] Melting the mixture at high temperature to form glass liquid;

[0016] The glass liquid is formed into a low wetting angle glass substrate.

[0017] Preferably, the melting temperature of the high temperature melting is 1550°C to 1650°C.

[0018] Preferably, the glass liquid is formed into a low wetting angle glass substrate by overflow down-drawing.

[0019] Furthermore, at 1260° C., the wetting angle between the glass liquid and zircon is less than 28.5°.

[0020] A low wetting angle glass substrate is prepared by using the above preparation method.

[0021] Furthermore, the strain point temperature of the low wetting angle glass substrate is 712°C to 750°C.

[0022] A display panel comprises the low wetting angle glass substrate mentioned above.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention discloses a low wetting angle glass substrate, the raw material components of which include SiO2, Al2O3, B2O3, MgO, CaO, SrO, BaO and K2O. SiO2 is the main network structure of the glass. In order to meet the necessary viscosity requirements of the glass production method, the overall molar percentage of SiO2 is controlled at 68.5% to 72%, which can maintain a relatively low density and ensure the lightweight requirements. Al2O3 has two coordination states in the glass, 4 and 6. When Al 3+ The ions are in the aluminum-oxygen tetrahedron [AlO4], forming a unified network with the silicon-oxygen tetrahedron, forming a complex aluminum-silicon-oxygen anion group, making the glass structure compact, thereby increasing the viscosity of the glass; when Al 3+ The ions are in the aluminum oxide octahedron [AlO6], which is a network outside body, destroying the network structure of the glass and reducing the viscosity of the glass. 3+ The coordination number of the ion mainly depends on the amount of free oxygen provided by the alkaline earth metal oxide in the glass melt. Invention The Al2O3 content in the raw material components of the present invention is 9.8% to 12.5%, RO / Al2O3 is greater than 1, Al 3+ The ions are mainly located in the aluminum oxide octahedron [AlO6], so while reducing the high-temperature viscosity of the glass, it can also ensure that the glass has a higher strain point temperature, increasing its thermal stability. B2O3 can reduce the high-temperature viscosity of the glass and promote the melting of the glass, especially in OLED display substrate glass. The high dimensional stability required leads to the high viscosity of the glass itself, and the melting process temperature increases accordingly. The content of B2O3 is 0.73% to 5%. On the one hand, it is mainly to increase the strain point of the glass while slightly reducing the viscosity of the glass; on the other hand, the lower B2O3 content reduces the difference between the surface and internal components of the glass caused by volatilization, and the glass performance is more stable. Alkaline earth metal oxides CaO, MgO, SrO and BaO are glass network exogenous oxides, and alkaline earth metal cations R 2+ Move more freely at high temperatures and have the ability to make O 2-Polarization weakens the effect of silicon-oxygen bonds, reducing the viscosity of the glass liquid; but when the temperature decreases, the cation R 2+ The migration ability of the alkaline earth metal is weakened, and it is possible to be in some silicon-oxygen tetrahedron groups according to a certain coordination relationship, and to combine small silicon-oxygen tetrahedrons into large silicon-oxygen tetrahedron groups, so the viscosity of the glass liquid is increased to some extent. Therefore, alkaline earth metal oxides can be beneficial to the clarification of glass liquid at high temperature and the molding of glass liquid at low temperature, but its excessive content will also increase the density, reduce the strain point temperature, deteriorate the chemical durability, and increase the thermal expansion coefficient. The mixed oxides of alkaline earth metals can reduce the liquidus temperature and increase the liquidus viscosity, which is beneficial to overflow pull-down production. Ca 2+ The coordination number is generally 6. Its activity in the glass network structure is very small and it is generally not easy to precipitate from the glass. However, it is highly active at high temperatures. 2+ It has the effect of polarizing oxygen and weakening silicon-oxygen bonds. When the CaO content in the glass is too much, it generally shortens the material properties of the glass, which is not conducive to molding, and the crystallization tendency of the glass increases. Therefore, the CaO content is controlled within 6%. If the CaO content is greater than 6%, the glass tends to crystallize more. Replacing part of CaO with MgO can reduce the effect of the glass's crystallization tendency. SrO has a similar effect to BaO. It can reduce the viscosity of the glass, which is beneficial to production and can improve the component of the glass's crystallization tendency, but it will sharply increase the density of the glass. Therefore, the SrO content is maintained between 0.5% and 2%. If the SrO content is greater than 2%, the density of the glass will increase; the BaO content is maintained at 1.6% to 5%. If the BaO content is greater than 5%, the density will increase significantly. If it is less than 1.6%, the crystallization tendency will increase, and it cannot adapt to the overflow down-drawing method. The density of the glass can be less than 2.6g / cm when the total sum of alkaline earth metal oxides is less than 16%. 3, meeting production requirements. Adding K2O as an alkali metal oxide can lower the melting temperature of glass, increase its conductivity, reduce the wetting angle of glass, and increase its wettability. The larger the radius of the alkali metal cation, the better its wettability and the smaller the wetting angle. However, alkali-containing glass cannot be used in the manufacture of LTPS TFT. This is because the thermal processing temperature is quite high when manufacturing LTPS TFT devices on glass. At this time, the alkali metal ions from the glass may pass through the SiO2 barrier layer and pollute the TFT gate dielectric material, destroying the performance of the TFT and causing a decrease in the device life. Therefore, the present application creatively adds K2O to the alkaline earth metal oxide and controls the molar mass percentage of K2O to 0.1% to 0.2%, which not only increases the wettability of the glass liquid, but also ensures that the performance of the TFT device is not affected by it. Through the joint action of the above components, the prepared glass substrate can ensure its unique mechanical properties and optical properties. At the same time, during the production process, the lower wetting angle can fully "wet" the surface of the overflow brick, reduce the friction between the glass liquid and the surface of the overflow brick when the overflow is pulled down, reduce the wear of the overflow brick, ensure that the size of the overflow brick is stable and not deformed, and make the amount of glass liquid flowing out between the far end and the near end of the overflow brick equal, that is, the flow of the glass liquid overflowing from the groove of the overflow brick is more stable, increase the thickness uniformity of the glass plate, ensure that the glass plate has a lower thickness variation, thereby ensuring the quality of the product, ensuring the service life of the overflow brick, and reducing the production cost.

[0025] The present invention provides a method for preparing a low wetting angle glass substrate as described above. The method achieves the preparation of a low wetting angle glass substrate by weighing raw material components according to molar percentage, mixing them evenly, melting them at high temperature, and finally forming them into a low wetting angle glass substrate. According to detection, at 1260°C, the wetting angle between the glass liquid and zircon is less than 28.5°, which can fully wet the surface of the overflow brick, reduce the friction between the glass liquid and the surface of the overflow brick when the overflow is pulled down, reduce the wear of the overflow brick, and ensure that the size of the overflow brick is stable and not deformed. The preparation method is simple and easy to operate, does not require the modification of existing production equipment, and is suitable for industrialization.

[0026] The present invention provides a low wetting angle glass substrate, which is prepared by the above-mentioned preparation method, and the strain point temperature of the glass substrate is 712° C. to 750° C. The thickness uniformity in the glass production process can be improved by a small wetting angle between the glass liquid and the overflow brick, which greatly improves the service life of the overflow brick and reduces the production cost.

[0027] A display panel comprises the low wetting angle glass substrate. The performance of the display panel is more stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a schematic flow chart of a method for preparing a low wetting angle glass substrate. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0032] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0033] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0034] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0036] The present invention discloses a low wetting angle glass substrate, which comprises the following components in terms of mole percentage:

[0037] SiO2 is 68.5% to 72%, Al2O3 is 9.8% to 12.5%, B2O3 is 0.73% to 5%, MgO is 4% to 6%, CaO is 4% to 6%, SrO is 0.5% to 2%, BaO is 1.6% to 5% and K2O is 0.1% to 0.2%; preferably, 0.1% SnO2 is also included, and SnO2 is added as a clarifier to improve the light transmittance of the substrate glass;

[0038] Among them, 0.9SiO2+0.5Al2O3+0.65B2O3+0.1MgO+2CaO+0.5SrO+0.5BaO+0.1K2O>0.83; the alkaline earth metal oxide RO in the raw material components is less than 16%, and the RO includes MgO, CaO, SrO and BaO.

[0039] See also Figure 1 The present invention provides a method for preparing the low wetting angle glass substrate as described above, comprising the following steps:

[0040] S1: weigh the raw material components according to molar percentage, mix them evenly to form a mixture, that is, 68.5% to 72% of SiO2, 9.8% to 12.5% ​​of Al2O3, 0.73% to 5% of B2O3, 4% to 6% of MgO, 4% to 6% of CaO, 0.5% to 2% of SrO, 1.6% to 5% of BaO and 0.1% to 0.2% of K2O are mixed evenly by a mixer to form a uniform mixture.

[0041] S2: melting the mixture at high temperature to form glass liquid, that is, feeding the uniformly mixed mixture into a glass melting furnace through a feeder, and melting it at 1550° C. to 1650° C. to form glass liquid;

[0042] S3: forming the glass liquid into a low wetting angle glass substrate, and forming the glass liquid into the low wetting angle glass substrate by an overflow down-drawing method.

[0043] Example 1

[0044] 71% SiO2, 12.5% ​​Al2O3, 0.73% B2O3, 1.1% SrO, 3.49% BaO, 5.19% CaO, 5.69% MgO, 0.2% K2O and 0.1% SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1550° C. to form molten glass; the molten glass is formed into a low wetting angle glass substrate by an overflow down-draw method.

[0045] Example 2

[0046] 68.5% of SiO2, 12.5% ​​of Al2O3, 2.7% of B2O3, 1% of SrO, 5% of BaO, 6% of CaO, 4% of MgO, 0.2% of K2O and 0.1% of SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1600° C. to form glass liquid; the glass liquid is formed into a low wetting angle glass substrate by an overflow down-pull method.

[0047] Example 3

[0048] 71% SiO2, 9.8% Al2O3, 5% B2O3, 1% SrO, 3% BaO, 4% CaO, 6% MgO, 0.1% K2O and 0.1% SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1600° C. to form molten glass; the molten glass is formed into a low wetting angle glass substrate by an overflow down-pull method.

[0049] Example 4

[0050] 68% SiO2, 12.5% ​​Al2O3, 3.5% B2O3, 0.5% SrO, 4% BaO, 5.9% CaO, 5.3% MgO, 0.2% K2O and 0.1% SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1550° C. to form molten glass; the molten glass is formed into a low wetting angle glass substrate by an overflow down-draw method.

[0051] Example 5

[0052] 70.5% SiO2, 12.5% ​​Al2O3, 2.53% B2O3, 0.5% SrO, 2.79% BaO, 5.39% CaO, 5.49% MgO, 0.2% K2O and 0.1% SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1600° C. to form glass liquid; the glass liquid is formed into a low wetting angle glass substrate by an overflow down-draw method.

[0053] Example 6

[0054] 69% SiO2, 12.4% Al2O3, 3.73% B2O3, 0.5% SrO, 3.09% BaO, 5.19% CaO, 5.89% MgO, 0.1% K2O and 0.1% SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1600° C. to form glass liquid; the glass liquid is formed into a low wetting angle glass substrate by an overflow down-draw method.

[0055] Example 7

[0056] 72% SiO2, 11.3% Al2O3, 2.5% B2O3, 1% SrO, 2.6% BaO, 5.2% CaO, 5.1% MgO, 0.2% K2O and 0.1% SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1600° C. to form molten glass; the molten glass is formed into a low wetting angle glass substrate by an overflow down-draw method.

[0057] Example 8

[0058] 71% SiO2, 12.4% Al2O3, 2.5% B2O3, 2% SrO, 1.6% BaO, 5.2% CaO, 5.1% MgO, 0.1% K2O and 0.1% SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1600° C. to form glass liquid; the glass liquid is formed into a low wetting angle glass substrate by an overflow down-draw method.

[0059] Comparative Example

[0060] 71% SiO2, 12.5% ​​Al2O3, 0.93% B2O3, 1.1% SrO, 3.49% BaO, 5.19% CaO, 5.69% MgO and 0.1% SnO2 are mixed evenly by a mixer to form a uniform mixture; the evenly mixed mixture is fed into a glass melting furnace by a feeder and melted at 1600° C. to form molten glass; the molten glass is formed into a low wetting angle glass substrate by an overflow down-draw method.

[0061] The composition and performance comparison of Examples 1 to 8 and the comparative example are shown in the table below:

[0062]

[0063]

[0064]

[0065] It can be seen that compared with the comparative example, the glass substrates prepared in Examples 1 to 8 can maintain consistent performance, but the low wetting angle glass substrates prepared in Examples 1-8 of the present invention have a smaller wetting angle between the glass liquid and the overflow brick, which can fully "wet" the surface of the overflow brick, reduce the friction between the glass liquid and the surface of the overflow brick when the overflow is pulled down, reduce the wear of the overflow brick, ensure that the size of the overflow brick is stable and not deformed, and the amount of glass liquid flowing out between the far end and the near end of the overflow brick is equal, which increases the thickness uniformity of the glass plate and ensures that the glass plate has a lower thickness variation.

[0066] A low wetting angle glass substrate is prepared by the above preparation method, and the thickness of the glass substrate is more uniform.

[0067] The present invention also provides a display panel, comprising the low wetting angle glass substrate. The display panel is more stable and has more reliable performance.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A low wetting angle glass substrate, characterized in that: The following raw material components are included by mole percentage: 71% SiO2, 9.8% Al2O3, 5% B2O3, 1% SrO, 3% BaO, 4% CaO, 6% MgO, 0.1% K2O and 0.1% SnO2, the low wetting angle glass substrate is a glass substrate for OLED display.

2. The method for preparing a low wetting angle glass substrate according to claim 1, wherein: The following steps are involved: Weigh the raw material components by mole percentage, mix them evenly, and form a mixture; Melting the mixture at high temperature to form glass liquid; The glass liquid is formed into a low wetting angle glass substrate.

3. The method for preparing a low wetting angle glass substrate according to claim 2, characterized in that: The melting temperature of high temperature melting is 1550℃~1650℃.

4. The method for preparing a low wetting angle glass substrate according to claim 2, characterized in that: The glass liquid is formed into a low wetting angle glass substrate by an overflow down-draw molding method.

5. The method for preparing a low wetting angle glass substrate according to claim 2, characterized in that: At 1260° C., the wetting angle between the glass liquid and zircon is less than 28.5°.

6. A low wetting angle glass substrate, characterized in that: Prepared by the preparation method according to any one of claims 2 to 5.

7. The low wetting angle glass substrate according to claim 6, characterized in that: Its strain point temperature is 712℃~750℃.

8. A display panel, characterized in that: The invention comprises the low wetting angle glass substrate as claimed in claim 1.

Images