Low-thermal-shrinkage glass and preparation method therefor

Abstract

To provide low-thermal-shrinkage glass and a preparation method therefor.SOLUTION: Low-thermal-shrinkage glass including the following raw material components in percentage by mole: 69.64 to 71% of SiO2, 12.5 to 13.34% of Al2O3, 0.73 to 1.68% of B2O3, 5.6 to 5.89% of MgO, 5.15 to 5.19% of CaO, 1.1 to 1.2% of SrO, 3.29 to 3.49% of BaO, and 0.1% of SnO2.EFFECT: The optimized composition provides a glass substrate with excellent chemical resistance, high Young's modulus, high deformation temperature, low thermal shrinkage, and high ultraviolet transmittance, meeting the demands of OLED display panels. Additionally, the small temperature difference between the surface and the interior allows for more effective avoidance of issues affecting product quality and production efficiency caused by glass loss at the platinum baffle position due to glass surface volatilization.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing glass for optoelectronic display, and more specifically, to low thermal shrinkage glass and a manufacturing method thereof.

Background Art

[0002] In the rapid progress of information technologies such as "Internet +", artificial intelligence, and wearable devices, display devices as information windows are required to have flexibility, thinness, light weight, power saving, foldable and rollable capabilities, and ultra-large sizes. For example, not only conventional display technologies such as Liquid Crystal Display (LCD) and Organic Light-Emitting Diode (OLED), but also new display technologies such as Mini-LED and Micro-LED have emerged. It is considered that the most core development of display technology currently and in the next few years will focus on technologies such as curved screens, full-screen displays, foldable screens, and transparent screens.

[0003] OLED display technology has the characteristics of self-emission and low power consumption, and can be used on substrates of any shape compared with conventional LCD display technology. Therefore, it has become the mainstream technology of flexible display technology. Low-temperature polycrystalline silicon thin-film transistors (LTPS TFTs) can manufacture smaller and faster transistors due to their high electron mobility characteristics, and have advantages such as high brightness, high resolution, and low power consumption. Therefore, LTPS-OLED technology can not only meet the requirements of high-resolution displays of conventional rigid screens, but also meet the requirements of flexible high-resolution displays.

[0004] Whether it is a conventional hard screen LTPS-OLED display or a flexible OLED screen, it is necessary to fabricate LTPS and OLED on a glass substrate. In the corresponding manufacturing process, the glass substrate is required to have performance such as a high Young's modulus, a low dimensional deformation amount, and a low thickness change amount.

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the substrate glass currently used in OLED displays easily devitrifies the glass at the platinum baffle parts at the distal and proximal ends on both sides of the brick tip during the overflow down-draw forming process. As a result, quality problems such as non-uniform thickness, cavities, and size variations occur on both sides of the glass plate. In severe cases, plate cracking occurs, seriously affecting the continuity of production. This is because it is necessary to wet the overflow brick before the first lift of the glass, and in the wetting process, the glass liquid stays at the platinum baffle part. Part of the B2O3 on the surface of the stayed glass liquid volatilizes over time, making the surface of the glass liquid more prone to devitrification. Even after normal lifting, the glass staying here is not completely covered by the new glass liquid. Therefore, devitrification of the glass occurs at the platinum baffle part after the production line has been operating for a certain period. As a conventional solution, there is a method of using auxiliary heating devices on both sides of the platinum baffle to "melt" the devitrified glass, melting the devitrified glass into a glass liquid with low viscosity and allowing it to flow down by its own weight. However, this operation method sacrifices production, and the production of the draw plate cannot be carried out during the melting process.

Means for Solving the Problems

[0006] Therefore, in order to address the problem existing in the prior art that the glass at the platinum baffle part easily devitrifies due to the volatilization of the glass surface, which affects the product quality and production efficiency, the present invention discloses a low thermal shrinkage glass.

[0007] In order to achieve the above object, the present invention adopts the following technical means. Disclosed is a low thermal shrinkage glass characterized by containing, as raw material components, 69.64 to 71% of SiO2, 12.5 to 13.34% of Al2O3, 0.73 to 1.68% of B2O3, 5.6 to 5.89% of MgO, 5.15 to 5.19% of CaO, 1.1 to 1.2% of SrO, 3.29 to 3.49% of BaO, and 0.1% of SnO2 in mole percentages.

[0008] Preferably, the mole percentage of RO is greater than the mole percentage of Al2O3, and RO is the sum of MgO, CaO, SrO, and BaO.

[0009] A method for manufacturing the above low thermal shrinkage glass, comprising: weighing raw material components according to mole percentages and uniformly mixing them to form a mixture; melting the mixture at a high temperature to form a glass melt; and shaping the glass melt to obtain a low thermal shrinkage glass.

[0010] Preferably, the melting temperature at the high temperature is 1550°C to 1600°C.

[0011] A low thermal shrinkage glass manufactured by the method for manufacturing a low thermal shrinkage glass, characterized in that the strain point temperature is 745°C to 750°C, and the thermal shrinkage rate after heat treatment at 600°C for 10 minutes reaches 7 to 9 ppm.

[0012] Furthermore, in the above low thermal shrinkage glass, the Young's modulus is 82 to 83 GPa, and the density is 2.59 g / cm 3 is.

[0013] Furthermore, in the above low thermal shrinkage glass, the thermal expansion coefficient in the range of 25°C to 380°C is 36.7×10 -7 ~39.6×10 -7 is.

[0014] Furthermore, in the above low thermal shrinkage glass, the corrosion amount per unit area when corroded in a 40% HF solution by mass at 25°C for 20 minutes is 4.7 to 4.9 mg / cm 2and the corrosion rate per unit area when corroded in a 5% NaOH solution by mass at 95°C for 360 minutes is 0.29 to 0.33 mg / cm 2 is as follows.

[0015] Furthermore, in the above low thermal shrinkage glass, the ultraviolet transmittance at a wavelength of 300 nm exceeds 70%, and the ultraviolet transmittance at a wavelength of 400 nm exceeds 90%.

[0016] Furthermore, in the above low thermal shrinkage glass, the internal devitrification viscosity is 300,000 poises, the surface devitrification viscosity is 250,000 poises, and the devitrification temperature difference is 7°C.

Advantages of the Invention

[0017] The low thermal shrinkage glass of the present invention has the following beneficial effects. The low thermal shrinkage glass according to the present invention contains SiO2, Al2O3, B2O3, MgO, CaO, SrO, BaO, and SnO2 as raw material components. The main role of SiO2 is to function as the main body of the glass network structure. By controlling the total molar percentage of SiO2 to 69.64 to 71%, the glass melt can meet the viscosity requirements necessary for the manufacturing method, prevent the temperature of the production process from becoming excessively high, and at the same time, can keep the density low and meet the requirements of weight reduction. Al2O3 has two coordination states in the glass. When Al 3+ ions are present in the aluminum oxygen tetrahedron [AlO4], they form a network integrated with the silicon oxygen tetrahedron, generating a complex aluminosilicate anion group. As a result, the glass structure becomes denser and the viscosity of the glass increases. On the other hand, Al 3+When ions are present in the aluminum oxygen octahedron [AlO6], they belong to the network modifiers, which can destroy the network structure of the glass and reduce the viscosity of the glass. B2O3 can reduce the high-temperature viscosity of the glass and promote the melting of the glass. Especially in the case of OLED display glass substrates, due to the requirement of high dimensional stability, the viscosity of the glass itself becomes particularly high, and accordingly, the temperature of the melting process increases. By setting the content of B2O3 to 0.73 - 1.68%, the strain point of the glass can be increased, thermal shrinkage can be reduced, and at the same time, the viscosity of the glass can be slightly reduced. On the other hand, with a low B2O3 content, the component difference between the glass surface and the interior caused by volatilization is reduced, and thereby the difference in devitrification temperature between the surface and the interior is reduced. This can reduce the tendency for the glass at the platinum baffle position to be more prone to devitrification. Alkaline earth metal oxides can reduce the overall viscosity of the glass melt, which is beneficial for reducing the production process temperature. However, when the content is excessive, the density increases, the strain point temperature decreases, and the chemical durability decreases. Therefore, the total amount of alkaline earth metal oxides is controlled to be 15.67 - 15.77%. At this time, the mixed oxide of alkaline earth metals can lower the liquidus temperature and increase the viscosity of the liquidus, thereby reducing the devitrification temperature inside and outside the glass, narrowing the temperature difference. The relatively small difference in devitrification temperature between the surface and the interior can more effectively avoid the impact on product quality and production efficiency caused by glass devitrification at the platinum baffle position caused by the volatilization of the glass surface.

[0018] By making the molar percentage of the alkaline earth metal oxide RO larger than the molar percentage of Al2O3, Al 3+ ions can be mainly arranged in the aluminum oxygen octahedron [AlO6]. Thereby, while reducing the high-temperature viscosity of the glass, it can be ensured that the glass has a small thermal shrinkage rate and a high Young's modulus.

[0019] Furthermore, the present invention discloses a method for manufacturing the above-mentioned low thermal shrinkage glass. In this method, raw material components are weighed according to molar percentages and uniformly mixed to form a mixture. Next, the mixture is melted at a high temperature to form a glass melt. Finally, the glass melt is shaped into low thermal shrinkage glass. The manufacturing method is simple and easy to operate, and does not require modification of equipment.

[0020] Moreover, the present invention discloses low thermal shrinkage glass manufactured using the above method. As a result of inspection, the strain point temperature of this low thermal shrinkage glass is 745 - 750 °C, and the thermal shrinkage rate after heat treatment for 10 minutes under the condition of 600 °C reaches 7 - 9 ppm. The Young's modulus is 82 - 83 GPa, the density is 2.59 g / cm 3 and the coefficient of thermal expansion in the range of 25 - 380 °C is 36.7×10 -7 ~39.6×10 -7 . The corrosion rate per unit area when corroded in a 40% HF solution by mass at 25 °C for 20 minutes is 4.7 - 4.9 mg / cm 2 and the corrosion rate per unit area when corroded in a 5% NaOH solution by mass at 95 °C for 360 minutes is 0.29 - 0.33 mg / cm 2 . The ultraviolet transmittance at a wavelength of 300 nm exceeds 70%, and the ultraviolet transmittance at a wavelength of 400 nm exceeds 90%. In the manufacturing process, since this glass has a high devitrification viscosity and a small devitrification temperature difference between the inside and the surface, the influence of devitrification of the glass caused by the long residence time of the glass on the product quality and production continuity can be effectively solved.

Brief Description of the Drawings

[0021]

Figure 1

Embodiments for Carrying Out the Invention

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, hereinafter, with reference to the drawings of the embodiments of the present invention, the technical solutions will be clearly and completely described. It is obvious that the embodiments described herein are only a part of the present invention and do not cover all embodiments. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0023] Therefore, the detailed description of the embodiments of the present invention shown in the following drawings does not limit the scope of the present invention protected by the claims, but only shows selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments that can be obtained by those of ordinary skill in the art without creative efforts are included in the protection scope of the present invention.

[0024] In the following drawings, for the sake of indicating similar symbols and characters for similar items, once an item is defined in a drawing, there is no need to further define or explain that item in subsequent drawings.

[0025] In the description of the embodiments of the present invention, when indicating orientation or positional relationships such as "upper", "lower", "horizontal", "inner", etc., they are based on the orientation or positional relationships shown in the drawings or the orientation or positional relationships in which the products of the present invention are usually arranged when in use. This is only for explaining and simplifying the present invention and does not imply or suggest that the indicated devices or elements have specific orientations, specific structures, and operations. Therefore, it should not be construed as a limitation of the present invention. Also, terms such as "first" and "second" are only used for distinguishing descriptions and do not imply or suggest relative importance.

[0026] Furthermore, when the term "horizontal" is used, it does not require that the component be absolutely horizontal, but means that it may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and it does not mean that its structure needs to be completely horizontal and it may be slightly inclined.

[0027] In the description of the embodiments of the present invention, unless otherwise specifically defined or limited, terms such as "installation", "attachment", "connection", "connection", etc. should be interpreted in a broad sense. For example, it may be a fixed connection, a removable connection or an integral connection. It may be a mechanical connection or an electrical connection. It may be directly connected or indirectly connected through an intermediate medium, and the two elements may communicate with each other inside. Those skilled in the art can understand what these terms specifically mean in the present invention according to the specific situation.

[0028] Hereinafter, the present invention will be described in more detail based on specific embodiments, but it is for interpreting the present invention and not for limiting the present invention.

[0029] The present invention discloses a low thermal shrinkage glass. The low thermal shrinkage glass according to the present invention contains the following raw material components in mole percentage: SiO2 is 69.64 - 71%, Al2O3 is 12.5 - 13.34%, B2O3 is 0.73 - 1.68%, MgO is 5.6 - 5.89%, CaO is 5.15 - 5.19%, SrO is 1.1 - 1.2%, BaO is 3.29 - 3.49%, and SnO2 is 0.1%. Among them, the mole percentage of RO is greater than the mole percentage of Al2O3, and RO is the sum of MgO, CaO, SrO and BaO.

[0030] Referring to FIG. 1, the manufacturing method of the low thermal shrinkage glass according to the present invention will be described. This method includes the following steps:

[0031] Step S1: Weigh the raw material components according to the mole percentage and mix them uniformly to form a mixture. That is, mix SiO2 at 69.64 - 71%, Al2O3 at 12.5 - 13.34%, B2O3 at 0.73 - 1.68%, MgO at 5.6 - 5.89%, CaO at 5.15 - 5.19%, SrO at 1.1 - 1.2%, BaO at 3.29 - 3.49%, and SnO2 at 0.1% uniformly to form a mixture.

[0032] Step S2: Melt the mixture at a high temperature to form a glass melt. That is, introduce the mixture into the glass furnace through a feeder, and heat the glass furnace to 1550 - 1600 °C to melt the mixture into a glass melt.

[0033] Step S3: Shape the glass melt into a low thermal shrinkage glass. That is, introduce the glass melt into a platinum supply passage to clarify it, and then perform overflow down-draw forming to obtain a low thermal shrinkage glass.

[0034] (Example 1) Mix 71% of SiO2, 12.5% of Al2O3, 0.73% of B2O3, 5.89% of MgO, 5.19% of CaO, 1.1% of SrO, 3.49% of BaO, and 0.1% of SnO2 uniformly by mole percentage to form a mixture. Introduce the obtained mixture into the glass furnace through a feeder, and heat the glass furnace to 1550 °C to melt the mixture into a glass melt. After introducing the glass melt into a platinum supply passage to clarify it, perform overflow down-draw forming to obtain a low thermal shrinkage glass with a thickness of 0.1 mm.

[0035] (Example 2) Mix 69.64% of SiO2, 13.34% of Al2O3, 1.68% of B2O3, 5.6% of MgO, 5.15% of CaO, 1.2% of SrO, 3.29% of BaO, and 0.1% of SnO2 uniformly by mole percentage to form a mixture. Introduce the obtained mixture into the glass furnace through a feeder, and heat the glass furnace to 1550 °C to melt the mixture into a glass melt. After introducing the glass melt into a platinum supply passage to clarify it, perform overflow down-draw forming to obtain a low thermal shrinkage glass with a thickness of 0.1 mm.

[0036] (Example 3) Mix 70% SiO2, 13% Al2O3, 1.55% B2O3, 5.7% MgO, 5.16% CaO, 1.1% SrO, 3.39% BaO, and 0.1% SnO2 uniformly in mole percentage to form a mixture. Feed the obtained mixture into a glass furnace through a feeder, heat the glass furnace to 1600 °C, and melt the mixture to obtain a glass melt. After introducing the glass melt into a platinum supply passage and clarifying it, perform overflow down-draw forming to obtain a low thermal shrinkage glass with a thickness of 0.1 mm.

[0037] As a result of conducting performance tests on the low thermal shrinkage glass produced in Examples 1 to 3, the following was revealed. The strain point temperature of the low thermal shrinkage glass produced using the above method was 745 °C to 750 °C. The thermal shrinkage rate after heat treatment at 600 °C for 10 minutes reached 7 to 9 ppm. The Young's modulus was 82 to 83 GPa. The density was 2.59 g / cm 3 It was. The coefficient of thermal expansion in the range of 25 °C to 380 °C was 36.7×10 -7 ~39.6×10 -7 It was. When corroded in a 40% HF solution by mass at 25 °C for 20 minutes, the corrosion amount per unit area was 4.7 to 4.9 mg / cm 2 It was. When corroded in a 5% NaOH solution by mass at 95 °C for 360 minutes, the corrosion amount per unit area was 0.29 to 0.33 mg / cm 2 It was. The transmittance for ultraviolet light with a wavelength of 300 nm exceeded 70%, and the transmittance for ultraviolet light with a wavelength of 400 nm exceeded 90%. The devitrification viscosity inside was 300,000 poises, the devitrification viscosity on the surface was 250,000 poises, and the devitrification temperature difference was 7 °C.

[0038] As described above, the present invention discloses a low thermal shrinkage glass and a method for manufacturing the same. With the optimized composition, a glass substrate having excellent chemical resistance, high Young's modulus, high strain point, low thermal shrinkage, and high ultraviolet transmittance can be obtained, which meets the requirements of the OLED display panel. At the same time, since the devitrification temperature difference between the surface and the inside is small, the problem that affects product quality and production efficiency caused by devitrification of the glass at the platinum baffle position due to volatilization of the glass surface can be more effectively avoided.

[0039] The above are only preferred embodiments of the present invention and are not intended to limit the technical solutions of the present invention. Those skilled in the art of this technology can also make simple modifications and substitutions to the technical solutions of the present invention without departing from the gist and principle of the present invention, and these modifications and substitutions are included within the scope of protection covered by the claims of the present invention.

Claims

1. 69.64 to 71% SiO as a raw material component in mole percentage ２ , 12.5 to 13.34% Al ２ O ３ , 0.73-1.68% B ２ O ３ , 5.6-5.89% MgO, 5.15-5.19% CaO, 1.1-1.2% SrO, 3.29-3.49% BaO, and 0.1% SnO ２ A low thermal shrinkage glass comprising:

2. The mole percentage of RO is Al ２ O ３ 2. The low thermal shrinkage glass of claim 1, wherein said RO is a sum of MgO, CaO, SrO and BaO.

3. A method for producing the low thermal shrinkage glass according to claim 1 or 2, Weighing and uniformly mixing the raw ingredients according to mole percentage to form a mixture; melting the mixture at an elevated temperature to form a glass melt; forming the glass melt to obtain a low thermal shrinkage glass; A method for producing low thermal shrinkage glass, comprising:

4. The method for producing low thermal shrinkage glass according to claim 3, wherein the melting temperature at the high temperature is 1550°C to 1600°C.

5. A low thermal shrinkage glass produced by the method for producing low thermal shrinkage glass according to claim 3 or 4, A low-thermal shrinkage glass having a strain point temperature of 745°C to 750°C and a thermal shrinkage rate of 7 to 9 ppm after heat treatment at 600°C for 10 minutes.

6. Young's modulus is 82-83 GPa and density is 2.59 g / cm ３ The low thermal shrinkage glass according to claim 5 .

7. The thermal expansion coefficient in the range of 25°C to 380°C is 36.7 x 10 －７ ~39.6 x 10 －７ The low thermal shrinkage glass according to claim 5 .

8. The amount of corrosion per unit area when corroded for 20 minutes in a 40% HF solution at 25°C is 4.7 to 4.9 mg / cm ２ The amount of corrosion per unit area when corroded for 360 minutes in a 5% NaOH solution at 95°C is 0.29 to 0.33 mg / cm ２ The low thermal shrinkage glass according to claim 5 .

9. 6. The low thermal shrinkage glass according to claim 5, having an ultraviolet ray transmittance of more than 70% at a wavelength of 300 nm and an ultraviolet ray transmittance of more than 90% at a wavelength of 400 nm.

10. 10. The low thermal shrinkage glass according to claim 5, having an internal devitrification viscosity of 300,000 poise, a surface devitrification viscosity of 250,000 poise, and a devitrification temperature difference of 7°C.

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