High-strength high borosilicate glass and preparation method thereof

Abstract

The invention relates to high-strength high borosilicate glass and a preparation method thereof, and belongs to the technical field of glass preparation, and the high-strength high borosilicate glass specifically comprises the following raw materials in parts by mass: 100 parts of quartz sand, 6-10 parts of borax, 5-9 parts of boric acid, 2-4 parts of aluminum hydroxide, 1-3 parts of sodium chloride, 0.5-1 part of yttrium oxide, 0.5-1 part of calcium oxide, 4-7 parts of sodium oxide and 0.5-3 parts of a compound additive, wherein the compound additive is prepared from zircon salt, other metal salts and calcium nitrate. According to the technical scheme, the performance of the high-strength and high-borosilicate glass is remarkably improved through innovation of the compound additive, optimization of the raw material ratio, improvement of the melting heat treatment procedure, optimization of homogenization and clarification treatment, optimization of compression molding parameters, improvement of the annealing treatment process and the synergistic effect of the whole process.

Description

Technical Field

[0001] This application relates to the technical field of glass preparation, and more specifically, it relates to a high-strength borosilicate glass and a preparation method thereof. Background Art

[0002] In the field of glass manufacturing, borosilicate glass is widely used in many industries such as kitchenware, optical instruments, and solar photovoltaic panels due to its excellent thermal stability, chemical stability, and mechanical strength. However, there are still some deficiencies in the existing borosilicate glass preparation technology, which limit the further improvement of its performance and the expansion of its application scope. In the traditional preparation process of borosilicate glass, the selection and use of the forming agent often have a crucial impact on the quality of the final product. However, many forming agents are prone to generating gases during the high-temperature treatment process. If these gases cannot be discharged in time, they will form bubbles in the glass melt, seriously affecting the transparency and overall quality of the glass. In addition, the existing heat treatment process has limitations in promoting the discharge of gases in the glass melt and improving the glass uniformity, resulting in fluctuations in the performance of the prepared borosilicate glass and making it difficult to meet the strict requirements of high-end applications for the consistency of material performance.

[0003] On the other hand, although there have been some attempts to enhance the performance of borosilicate glass by adding specific oxides, these additives often have complex effects on the melting process and final performance of the glass. For example, some additives may accelerate the increase in the viscosity of the glass, which is not conducive to the removal of impurities and the clarification of the glass; while some may have adverse reactions with other components in the glass, affecting the overall performance of the glass.

[0004] Based on the above statements, this application provides a high-strength borosilicate glass and a preparation method thereof. Summary of the Invention

[0005] To solve the problems raised in the background art, this application provides a high-strength borosilicate glass and a preparation method thereof. The technical solution of the present invention significantly improves the mechanical strength, chemical stability, thermal stability, and optical properties of the high-strength borosilicate glass through the innovation of composite additives, the optimization of raw material ratios, the improvement of the melting heat treatment process, the optimization of homogenization and clarification treatment, the optimization of pressing parameters, the improvement of annealing treatment process, and the synergistic effect of the overall process. At the same time, it reduces the production cost, improves the production efficiency and product yield.

[0006] This application provides a high-strength borosilicate glass and a preparation method thereof, adopting the following technical solutions: A high-strength borosilicate glass, comprising the following raw materials in parts by mass: 100 parts of quartz sand, 6 - 10 parts of borax, 5 - 9 parts of boric acid, 2 - 4 parts of aluminum hydroxide, 1 - 3 parts of sodium chloride, 0.5 - 1 part of yttrium oxide, 0.5 - 1 part of calcium oxide, 4 - 7 parts of sodium oxide and 0.5 - 3 parts of compound auxiliary agent; wherein, the compound auxiliary agent is composed of zirconium salt, other metal salts and calcium nitrate.

[0007] Further, the other metal salts in the compound auxiliary agent are at least one of potassium salt, zinc salt and magnesium salt.

[0008] Further, the compound auxiliary agent is specifically prepared by the following steps: Add zirconium salt, other metal salts and calcium nitrate into deionized water, stir at a rate of 30 - 90 rpm until uniform at room temperature, then add acid solution to the system, adjust the pH value of the system to 4 - 5, then raise the temperature of the system to 70 - 80 °C and stir at a rate of 30 - 90 rpm for 2 - 3 hours, then let it stand for gelation for 20 - 30 hours and dry at 80 - 100 °C for 15 - 20 hours to obtain the compound auxiliary agent.

[0009] In the above reaction process, a composite material of zirconium salt, other metal salts and calcium nitrate is prepared by the sol - gel method. The zirconium salt and other metal salts undergo hydrolysis reactions in an acidic environment to form corresponding metal hydroxides or oxyhydroxide compounds, and further polycondensation reactions occur in the system to form a metal - oxygen bond network structure. During the process, calcium ions in the system play a bridging role by forming coordination bonds with oxygen atoms in the hydrolysis products of metal salts, connecting different metal - oxygen bond networks together. This cross - linking effect enhances the three - dimensional network structure of the gel, improves the mechanical strength and stability of the gel, and then after drying, a compound auxiliary agent composed of zirconium oxide, metal oxides corresponding to other metal salts and calcium nitrate is obtained. After subsequent heat treatment, composite particles are formed and used as components of high - borosilicate glass.

[0010] Further, the molar ratio of zirconium salt, other metal salts and calcium nitrate is (0.1 - 1):(0.1 - 1):(3 - 5).

[0011] A preparation method of high - strength high - borosilicate glass specifically includes the following preparation steps: S1. Raw material mixing: Mix 100 parts of quartz sand, 6 - 10 parts of borax, 5 - 9 parts of boric acid, 2 - 4 parts of aluminum hydroxide, 1 - 3 parts of sodium chloride, 0.5 - 1 part of yttrium oxide, 0.5 - 1 part of calcium oxide, 4 - 7 parts of sodium oxide and 0.5 - 3 parts of compound auxiliary agent evenly to obtain a mixed material; S2. High - temperature melting: Transfer the mixed material obtained in step S1 to a glass melting furnace, and after the melting heat treatment process, obtain a glass melt; S3. Forming treatment: Carry out homogenization and clarification treatment on the glass melt obtained in step S2, and after cooling, press it into shape to obtain formed glass; S4. Place the formed glass obtained in step S3 in an annealing furnace for annealing treatment to obtain a high-strength borosilicate glass.

[0012] Further, in step S2, the specific operation of the melting and heat treatment process is as follows: Heat the mixture obtained in step S1 at a heating rate of 15 - 20 °C / min to 800 - 900 °C and hold for 1 - 2 hours; then continue to increase the temperature at a heating rate of 10 - 20 °C / min to 1200 - 1300 °C and hold for 20 - 40 minutes, and then increase the temperature at a heating rate of 10 - 20 °C / min to 1650 - 1700 °C and hold for 2 hours.

[0013] Further, in step S3, the specific operations of the homogenization treatment and clarification treatment are as follows: Set the temperature of the glass melt at 1400 - 1500 °C and hold for 0.5 - 1 hour for homogenization treatment; then cool the system temperature to 1300 - 1400 °C at a rate of 10 - 20 °C / min and stand for 0.5 - 1 hour for clarification treatment.

[0014] Further, in step S3, the temperature for press forming is 1000 - 1100 °C and the pressing pressure is 10 - 30 Mpa.

[0015] Further, in step S4, the specific operation of the annealing treatment is as follows: Reduce the formed glass to 500 - 600 °C at a rate of 1 - 5 °C / min, hold for 1 - 2 hours, and then cool to room temperature at a rate of 0.5 - 2 °C / min.

[0016] In summary, the present application has the following beneficial effects: In the technical solution of the present invention, a composite material obtained by drying metal oxides and calcium nitrate is used as a composite forming agent for borosilicate glass to prepare borosilicate glass. As a nitrate, calcium nitrate can promote clarification in the borosilicate glass melt. Coupled with the heat treatment at 800 - 900 °C during the staged heat treatment process, solid solution composite particles can be formed to capture the CO2 gas generated during the process, promote the aggregation of gas near the solid solution composite particles, facilitate the concentration of gas in the glass melt, make the bubbles grow continuously, and then accelerate the rise and overflow of the bubbles, reduce the gas that may appear in the system, and improve the transparency of the final glass product.

[0017] Through the heat treatment process at 1200 - 1300 °C, the phase transformation between quartz and cristobalite can be promoted, the unity of the crystal phase can be enhanced, the uniformity of the glass product can be improved, which helps to improve the overall performance of the material and reduce the performance fluctuations. And in the technical solution of the present invention, an appropriate amount of yttrium oxide is used to strengthen the borosilicate glass. Yttrium oxide in the borosilicate system increases the coordination number of boron, promoting the transformation of boron oxygen triangles into boron oxygen tetrahedrons. During this heat treatment process (1200 - 1300 °C), the degree of linkage in the glass network increases, further delaying the dissolution of SiO2 in the glass material, retarding the increase in the viscosity of the glass melt, facilitating the removal of impurity gases, and further promoting the clarification of the glass melt. Detailed implementation manners

[0018] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0019] In the specific implementation manner of this application, the particle size of the quartz sand used is 120 μm - 180 μm; the acid solution used is citric acid.

[0020] Example 1 A high-strength borosilicate glass, comprising the following raw materials in parts by mass: 100 parts of quartz sand, 6 parts of borax, 5 parts of boric acid, 2 parts of aluminum hydroxide, 1 part of sodium chloride, 0.5 part of yttrium oxide, 0.5 part of calcium oxide, 4 parts of sodium oxide, and 0.5 part of a composite additive; Among them, the composite additive is specifically prepared by the following steps: Add zirconium salt, other metal salts, and calcium nitrate to deionized water, stir evenly at a rate of 30 rpm at room temperature, then add the acid solution to the system, adjust the pH value of the system to 4, then raise the system temperature to 70 °C and stir at a rate of 30 rpm for 2 hours, then let it stand for gelation for 20 hours and dry at 80 °C for 15 hours to obtain the composite additive; among them, the molar ratio of zirconium salt, other metal salts, and calcium nitrate is 0.1:0.1:3; among them, the zirconium salt is ZrO(NO3)2, and the other metal salt is zinc nitrate.

[0021] The preparation method of the borosilicate glass includes the following steps: S1. Raw material mixing: Mix 100 parts of quartz sand, 6 parts of borax, 5 parts of boric acid, 2 parts of aluminum hydroxide, 1 part of sodium chloride, 0.5 part of yttrium oxide, 0.5 part of calcium oxide, 4 parts of sodium oxide, and 0.5 part of the composite additive evenly to obtain a mixture; S2. High-temperature melting: Transfer the mixture obtained in step S1 to a glass melting furnace. After the melting heat treatment process, a glass melt is obtained. The specific operation of the melting heat treatment process is as follows: Heat the mixture obtained in step S1 at a heating rate of 15 °C / min to 800 °C and hold for 1 hour. Then continue to increase the temperature to 1200 °C at a heating rate of 10 °C / min and hold for 20 minutes. Subsequently, increase the temperature to 1650 °C at a heating rate of 10 °C / min and hold for 2 hours. S3. Forming treatment: Homogenize and clarify the glass melt obtained in step S2, cool it, and then press it into shape to obtain a formed glass. During the process, set the temperature of the glass melt to 1400 °C (cooling rate: 10 °C / min) and hold for 0.5 hour for homogenization treatment. Then cool the system temperature to 1300 °C at a rate of 10 °C / min and let it stand for 0.5 hour for clarification treatment. During the process, set the temperature for pressing into shape to 1000 °C and the pressing pressure to 20 Mpa. S4. Place the formed glass obtained in step S3 in an annealing furnace for annealing treatment to obtain a high-strength borosilicate glass. During the process, the specific operation of the annealing treatment is as follows: Reduce the formed glass to 500 °C at a rate of 1 °C / min, hold for 1 hour, and then cool it to room temperature at a rate of 0.5 °C / min.

[0022] Example 2 A high-strength borosilicate glass, comprising the following raw materials in parts by mass: 100 parts of quartz sand, 8 parts of borax, 7 parts of boric acid, 3 parts of aluminum hydroxide, 3 parts of sodium chloride, 0.8 part of yttrium oxide, 0.7 part of calcium oxide, 5 parts of sodium oxide, and 1.5 parts of a composite additive; Among them, the composite additive is specifically prepared by the following steps: Add zirconium salt, other metal salts, and calcium nitrate to deionized water, stir evenly at a rate of 60 rpm at room temperature, then add acid solution to the system, adjust the pH value of the system to 4, raise the system temperature to 70 °C, and stir at a rate of 30 rpm for 2 hours. Then let it stand for gelation for 25 hours and dry it at 90 °C for 17 hours to obtain the composite additive. Among them, the molar ratio of zirconium salt, other metal salts, and calcium nitrate is 0.5:0.5:4. Among them, the zirconium salt is ZrO(NO3)2, and the other metal salt is zinc nitrate.

[0023] The preparation method of the borosilicate glass includes the following steps: S1. Raw material mixing: Mix 100 parts of quartz sand, 8 parts of borax, 7 parts of boric acid, 3 parts of aluminum hydroxide, 3 parts of sodium chloride, 0.8 part of yttrium oxide, 0.7 part of calcium oxide, 5 parts of sodium oxide, and 1.5 parts of the composite additive in accordance with the formula quantity to obtain a mixture. S2. High-temperature melting: Transfer the mixture obtained in step S1 to a glass melting furnace. After undergoing the melting heat treatment process, a glass melt is obtained. The specific operation of the melting heat treatment process is as follows: Heat the mixture obtained in step S1 at a heating rate of 20 °C / min to 850 °C and hold for 1.5 hours. Subsequently, continue to increase the temperature to 1250 °C at a heating rate of 15 °C / min and hold for 30 minutes. Then, increase the temperature to 1680 °C at a heating rate of 15 °C / min and hold for 2 hours. S3. Forming treatment: Perform homogenization and clarification on the glass melt obtained in step S2, cool it, and then press it into shape to obtain formed glass. During the process, set the temperature of the glass melt to 1450 °C (cooling rate: 10 °C / min) and hold for 0.5 hours for homogenization treatment. Subsequently, cool the system temperature to 1350 °C at a rate of 15 °C / min and let it stand for 0.5 hours for clarification treatment. During the process, set the temperature for pressing into shape to 1000 °C and the pressing pressure to 20 Mpa. S4. Place the formed glass obtained in step S3 in an annealing furnace for annealing treatment to obtain a high-strength borosilicate glass. During the process, the specific operation of the annealing treatment is as follows: Reduce the temperature of the formed glass to 550 °C at a rate of 3 °C / min, hold for 1.5 hours, and then cool it to room temperature at a rate of 1 °C / min.

[0024] Example 3 A high-strength borosilicate glass, comprising the following raw materials in parts by mass: 100 parts of quartz sand, 10 parts of borax, 9 parts of boric acid, 4 parts of aluminum hydroxide, 3 parts of sodium chloride, 1 part of yttrium oxide, 1 part of calcium oxide, 7 parts of sodium oxide, and 3 parts of a composite additive; Among them, the composite additive is specifically prepared by the following steps: Add zirconium salt, other metal salts, and calcium nitrate to deionized water, stir evenly at a rate of 90 rpm at room temperature, then add acid solution to the system, adjust the pH value of the system to 5, raise the system temperature to 80 °C, and stir at a rate of 90 rpm for 3 hours. Then, let it stand for gelation for 30 hours and dry it at 100 °C for 20 hours to obtain the composite additive. Among them, the molar ratio of zirconium salt, other metal salts, and calcium nitrate is 1:1:5. Among them, the zirconium salt is ZrO(NO3)2, and the other metal salt is magnesium nitrate.

[0025] The preparation method of the borosilicate glass comprises the following steps: S1. Raw material mixing: Mix 100 parts of quartz sand, 10 parts of borax, 9 parts of boric acid, 4 parts of aluminum hydroxide, 3 parts of sodium chloride, 1 part of yttrium oxide, 1 part of calcium oxide, 7 parts of sodium oxide, and 3 parts of the composite additive in accordance with the formula amounts to obtain a mixture. S2. High-temperature melting: Transfer the mixture obtained in step S1 to a glass melting furnace. After the melting heat treatment process, a glass melt is obtained. The specific operation of the melting heat treatment process is as follows: Heat the mixture obtained in step S1 at a heating rate of 20 °C / min to 900 °C and hold for 2 hours. Then continue to increase the temperature to 1300 °C at a heating rate of 20 °C / min and hold for 40 minutes. Subsequently, increase the temperature to 1700 °C at a heating rate of 20 °C / min and hold for 2 hours. S3. Forming treatment: Homogenize and clarify the glass melt obtained in step S2, cool it, and then press it into shape to obtain formed glass. During the process, set the temperature of the glass melt to 1500 °C (cooling rate: 10 °C / min) and hold for 1 hour for homogenization treatment. Then cool the system temperature to 1400 °C at a rate of 20 °C / min and let it stand for 1 hour for clarification treatment. During the process, set the temperature for pressing into shape to 1100 °C and the pressing pressure to 30 Mpa. S4. Place the formed glass obtained in step S3 in an annealing furnace for annealing treatment to obtain a high-strength high-borosilicate glass. During the process, the specific operation of the annealing treatment is as follows: Reduce the formed glass to 600 °C at a rate of 5 °C / min, hold for 2 hours, and then cool it to room temperature at a rate of 2 °C / min.

[0026] Comparative Example 1 The difference between this comparative example and Example 1 is that yttrium oxide is not added in this comparative example. Specifically, a high-strength high-borosilicate glass includes the following raw materials in parts by mass: 100 parts of quartz sand, 6 parts of borax, 5 parts of boric acid, 2 parts of aluminum hydroxide, 1 part of sodium chloride, 0.5 part of calcium oxide, 4 parts of sodium oxide, and 0.5 part of composite additive.

[0027] Comparative Example 2 The difference between this comparative example and Example 1 is that the amount of yttrium oxide used in this comparative example is 2 parts. Specifically, a high-strength high-borosilicate glass includes the following raw materials in parts by mass: 100 parts of quartz sand, 6 parts of borax, 5 parts of boric acid, 2 parts of aluminum hydroxide, 1 part of sodium chloride, 0.5 part of calcium oxide, 2 parts of yttrium oxide, 4 parts of sodium oxide, and 0.5 part of composite additive.

[0028] Comparative Example 3 The difference between this comparative example and Example 1 is that the composite additive is obtained by mixing zirconium salt, other metal salts, and calcium nitrate in a molar ratio of 0.1:0.1:3.

[0029] Comparative Example 4 The difference between this comparative example and Example 1 is that in Step S2, no first-stage heat treatment gradient is set in the melting heat treatment. Specifically: The specific operation of the melting heat treatment process is as follows: The mixture obtained in Step S1 is further heated to 1200°C at a heating rate of 10°C / min and held for 20 minutes, and then heated to 1650°C at a heating rate of 10°C / min and held for 2 hours.

[0030] Comparative Example 5 The difference between this comparative example and Example 1 is that in Step S2, no second-stage heat treatment gradient is set in the melting heat treatment. Specifically, the specific operation of the melting heat treatment process is as follows: The mixture obtained in Step S1 is heated to 800°C at a heating rate of 15°C / min and held for 1 hour; then heated to 1650°C at a heating rate of 10°C / min and held for 2 hours.

[0031] Performance Test The high-borosilicate glass samples prepared in Examples 1-3 and Comparative Examples 1-5 of this application are made into samples with a thickness of 5 mm, and the performance of the samples in each group is tested.

[0032] Referring to the test method in GB / T 34843-2017, the linear thermal expansion coefficient (20-300°C) of the product is detected. Referring to the test method in GB / T 37780-2019, the shear modulus and elastic modulus of the product are detected. Referring to the method in GB / T7962.8-2010, the bubble degree of the sample is tested.

[0033] Among them, the bubble degree grade is divided according to the total cross-sectional area of bubbles in the glass (mm 2 / 100 cm 2 ), and is specifically divided into the following seven grades: Grade A00: 0.003 - 0.01 Grade A0: 0.01 - 0.03 Grade A: 0.03 - 0.10 Grade B: 0.10 - 0.25 Grade C: 0.25 - 0.50 Grade D: 0.50 - 1.00 Grade E: greater than 1.00 The specific test results are shown in Table 1 below.

[0034] Table 1

[0035] From the results shown in Table 1 above, it can be seen that the performance of the high borosilicate glass prepared in Examples 1-3 of the present application is better than that of the samples prepared in the comparative examples. From the results of Comparative Examples 1 and 2, it can be seen that an appropriate amount of yttrium oxide can promote the performance of high borosilicate glass including elastic modulus and linear expansion coefficient. However, when the yttrium oxide content increases, due to the Y 3+ The ion field is too strong, forcing the bridging oxygen to become non-bridging oxygen and arrange in Y 3+ Around, the structure of the boron-oxygen tetrahedron in the high borosilicate glass system is destroyed, making the content of boron-oxygen tetrahedron in the system higher than that of boron-oxygen triangle, the viscosity of the glass melt decreases, the glass-forming performance of the material decreases, and the performance of the product in all aspects decreases. From the results in Comparative Examples 3-5, it can be seen that the composite additive obtained by using zirconium salt, other metal salts and calcium nitrate, combined with the heat treatment process in this scheme, can improve the quality of the glass melt and improve the performance of the high borosilicate glass product.

[0036] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0037] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A high-strength high-borosilicate glass, characterized in that: Including the following raw materials by weight: 100 parts of quartz sand, 6-10 parts of borax, 5-9 parts of boric acid, 2-4 parts of aluminum hydroxide, 1-3 parts of sodium chloride, 0.5-1 parts of yttrium oxide, 0.5-1 parts of calcium oxide, 4-7 parts of sodium oxide and 0.5-3 parts of composite additives; wherein the composite additives are composed of zirconium salts, other metal salts and calcium nitrate.

2. The high-strength high-borosilicate glass according to claim 1, characterized in that: The other metal salt in the composite auxiliary agent is at least one of potassium salt, zinc salt and magnesium salt.

3. The high-strength high-borosilicate glass according to claim 1, characterized in that: The composite auxiliary agent is specifically prepared by the following steps: Add zirconium salt, other metal salts and calcium nitrate into deionized water, stir until uniform at room temperature, adjust the pH value of the system to 4-5, increase the system temperature to 70-80°C and stir for 2-3 hours, then let it stand for gelation for 20-30 hours and then dry to obtain the composite additive.

4. The high-strength high-borosilicate glass according to claim 3, characterized in that: The molar ratio of zirconium salt, other metal salt and calcium nitrate is (0.1-1):(0.1-1):(3-5).

5. A method for preparing high-strength high-borosilicate glass as claimed in any one of claims 1 to 4, characterized in that: The specific preparation steps include: S1. Raw material mixing: uniformly mix quartz sand, borax, boric acid, aluminum hydroxide, sodium chloride, yttrium oxide, calcium oxide, sodium oxide and composite additives in the prescribed amount to obtain a mixture; S2, high temperature melting: transferring the mixture obtained in step S1 to a glass melting furnace, and obtaining a glass melt after a melting heat treatment process; S3, molding process: homogenizing and clarifying the glass melt obtained in step S2, and pressing and molding after cooling to obtain molded glass; S4. Placing the formed glass obtained in step S3 in an annealing furnace for annealing to obtain a high-strength high-borosilicate glass.

6. The method for preparing high-strength high-borosilicate glass according to claim 5, characterized in that: In step S2, the specific operation of the melt heat treatment process is: The mixture obtained in step S1 is heated to 800-900°C at a heating rate of 15-20°C / min and maintained for 1-2 hours; then the temperature is further increased to 1200-1300°C at a heating rate of 10-20°C / min and maintained for 20-40 minutes, and then the temperature is increased to 1650-1700°C at a heating rate of 10-20°C / min and maintained for 2 hours.

7. The method for preparing high-strength high-borosilicate glass according to claim 5, characterized in that: In step S3, the specific operations of the homogenization and clarification treatment are as follows: The temperature of the molten glass is set to 1400-1500°C and maintained for 0.5-1 hour for homogenization treatment; then the system temperature is cooled to 1300-1400°C at a rate of 10-20°C / min and allowed to stand for 0.5-1 hour for clarification treatment.

8. The method for preparing high-strength high-borosilicate glass according to claim 5, characterized in that: In step S3, the pressing temperature is 1000-1100°C and the pressing pressure is 10-30Mpa.

9. The method for preparing high-strength high-borosilicate glass according to claim 5, characterized in that: In step S4, the specific operation of the annealing treatment is: The molded glass is cooled to 500-600°C at a rate of 1-5°C / min, maintained for 1-2 hours, and then cooled to room temperature at a rate of 0.5-2°C / min.

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