A high-strength high-borosilicate glass and its preparation method

Abstract

The present invention relates to a kind of high-strength high borosilicate glass and preparation method thereof, belong to the field of glass preparation technology, specifically include the following raw materials 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 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. The technical solution of the present invention significantly improves the performance of high-strength high borosilicate glass through the innovation of composite additives, optimization of raw material ratio, improvement of melt heat treatment process, optimization of homogenization and clarification treatment, optimization of press molding parameters, improvement of annealing treatment process and synergistic effect of the overall process.

Description

Technical Field

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

[0002] In the field of glass manufacturing, high 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, the existing high borosilicate glass preparation technology still has some shortcomings, which limits its further improvement in performance and the expansion of its application scope. In the traditional high borosilicate glass preparation process, the selection and use of forming agents often have a crucial impact on the quality of the final product. However, many forming agents are prone to produce gases during high-temperature treatment. If these gases are not discharged in time, bubbles will form in the glass liquid, seriously affecting the transparency and overall quality of the glass. In addition, the existing heat treatment process still has limitations in promoting the discharge of gas in the glass liquid and improving the uniformity of the glass, resulting in fluctuations in the performance of the prepared high borosilicate glass, which is difficult to meet the strict requirements of high-end applications for material performance consistency.

[0003] On the other hand, while some attempts have been made to enhance the properties of borosilicate glass by adding specific oxides, these additives often have complex effects on the glass's melting process and final properties. For example, some additives may accelerate the increase in glass viscosity, hindering impurity removal and glass clarification; while others may react adversely with other components in the glass, affecting its overall properties.

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

[0005] To address the issues raised in the background technology, the present application provides a high-strength high-borosilicate glass and a method for preparing the same. The technical solution of the present invention significantly improves the mechanical strength, chemical stability, thermal stability, and optical properties of high-strength high-borosilicate glass through the innovation of composite additives, optimization of raw material ratios, improvement of the melt heat treatment process, optimization of homogenization and clarification treatments, optimization of press molding parameters, improvement of the annealing process, and the synergistic effect of the overall process, while reducing production costs and improving production efficiency and product yield.

[0006] This application provides a high-strength high-borosilicate glass and a preparation method thereof, using the following technical solutions:

[0007] A high-strength high-borosilicate glass comprises the following raw materials in parts by weight:

[0008] 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 composite additives; wherein the composite additives are composed of zirconium salts, other metal salts and calcium nitrate.

[0009] Furthermore, the other metal salt in the composite auxiliary agent is at least one of potassium salt, zinc salt and magnesium salt.

[0010] Furthermore, the compounding agent is specifically prepared by the following steps:

[0011] Zirconium salt, other metal salts and calcium nitrate are added to deionized water and stirred at 30-90 rpm at room temperature until uniform. Then, acid solution is added to the system, the pH value of the system is adjusted to 4-5, and then the system temperature is increased to 70-80°C and stirred at 30-90 rpm for 2-3 hours. Then, the system is allowed to stand for gelation for 20-30 hours and then dried at 80-100°C for 15-20 hours to obtain a composite additive.

[0012] During the above reaction process, a composite material of zirconium salt, other metal salt and calcium nitrate is prepared by a sol-gel method. Zirconium salt and other metal salts undergo hydrolysis reaction in an acidic environment to generate corresponding metal hydroxides or oxyhydroxy compounds, and further polycondensation reaction occurs in the system to generate a metal oxygen bond network structure. During the process, the calcium ions in the system form coordination bonds with the oxygen atoms in the hydrolysis products of the metal salts to act as bridges, 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 composite additive composed of zirconium oxide, the metal oxides corresponding to other metal salts and calcium nitrate is obtained. After subsequent heat treatment, composite particles are formed as components of high borosilicate glass.

[0013] Furthermore, the molar ratio of the zirconium salt, the other metal salt and the calcium nitrate is (0.1-1):(0.1-1):(3-5).

[0014] A method for preparing high-strength borosilicate glass specifically comprises the following preparation steps:

[0015] 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;

[0016] 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;

[0017] S3, forming process: homogenizing and clarifying the glass melt obtained in step S2, and pressing and forming it after cooling to obtain formed glass;

[0018] S4. Placing the formed glass obtained in step S3 in an annealing furnace for annealing treatment to obtain a high-strength high-borosilicate glass.

[0019] Furthermore, in step S2, the specific operation of the melt heat treatment process is:

[0020] 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, 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.

[0021] Furthermore, in step S3, the specific operations of the homogenization and clarification treatment are:

[0022] The glass melt temperature 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.

[0023] Furthermore, in step S3, the pressing temperature is 1000-1100° C., and the pressing pressure is 10-30 MPa.

[0024] Furthermore, in step S4, the specific operation of the annealing treatment is:

[0025] The formed 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.

[0026] In summary, this application has the following beneficial effects:

[0027] 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 high borosilicate glass to prepare high borosilicate glass. Calcium nitrate, as a nitrate, can promote clarification in the high borosilicate glass liquid. In combination with heat treatment at 800-900°C during the stage 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, and help concentrate the gas in the glass liquid, causing the bubbles to grow continuously, thereby accelerating the rising and overflow of bubbles, reducing the possible gas in the system, and improving the transparency of the final glass product.

[0028] Through the heat treatment process at 1200-1300℃, the crystal phase transition between quartz and cristobalite can be promoted, promoting the unification of the crystal phase, improving the uniformity of the glass product, helping to improve the overall performance of the material, and reducing performance fluctuations. In addition, in the technical solution of the present invention, an appropriate amount of yttrium oxide is used to strengthen the high-borosilicate glass. Yttrium oxide increases the coordination number of boron in the high-borosilicate system and promotes the transformation of boron-oxygen triangles to boron-oxygen tetrahedra. During this heat treatment process (1200-1300℃), the degree of linkage in the glass network increases, further delaying the dissolution of SiO2 in the glass material, delaying the increase in the viscosity of the glass liquid, facilitating the removal of impurity gases, and further promoting the clarification of the glass melt. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] The quartz sand used in the specific implementation of the present application has a particle size of 120 μm-180 μm; the acid used is citric acid.

[0031] Example 1

[0032] A high-strength high-borosilicate glass comprises the following raw materials in parts by weight:

[0033] 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 parts of yttrium oxide, 0.5 parts of calcium oxide, 4 parts of sodium oxide and 0.5 parts of composite additives;

[0034] Wherein, the composite adjuvant is specifically prepared by the following steps:

[0035] Zirconium salt, other metal salts and calcium nitrate are added to deionized water and stirred at 30 rpm at room temperature until uniform. Then, acid solution is added to the system, the pH value of the system is adjusted to 4, the system temperature is increased to 70°C and stirred at 30 rpm for 2 hours, and then the system is allowed to stand for gelation for 20 hours and then dried at 80°C for 15 hours to obtain a composite auxiliary agent; wherein the molar ratio of the zirconium salt, other metal salts and calcium nitrate is 0.1:0.1:3; wherein the zirconium salt is ZrO(NO3)2 and the other metal salt is zinc nitrate.

[0036] The method for preparing the high borosilicate glass comprises the following steps:

[0037] 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;

[0038] S2, high-temperature melting: The mixed material obtained in step S1 is transferred to a glass melting furnace and subjected to a melting heat treatment process to obtain a glass melt; wherein the specific operations of the melting heat treatment process are as follows:

[0039] The mixture obtained in step S1 was heated to 800°C at a heating rate of 15°C / min and held for 1 hour; then the temperature was further increased to 1200°C at a heating rate of 10°C / min and held for 20 minutes; then the temperature was increased to 1650°C at a heating rate of 10°C / min and held for 2 hours;

[0040] S3, molding process: homogenizing and clarifying the molten glass obtained in step S2, and then pressing and molding it to obtain molded glass; during the process, the temperature of the molten glass is set to 1400°C (cooling rate is 10°C / min) and maintained for 0.5 hours for homogenization; then, the system temperature is cooled to 1300°C at a rate of 10°C / min and allowed to stand for 0.5 hours for clarification; during the process, the pressing molding temperature is set to 1000°C and the pressing pressure is set to 20 MPa;

[0041] S4, placing the formed glass obtained in step S3 in an annealing furnace for annealing to obtain a high-strength high-borosilicate glass;

[0042] During the annealing process, the specific operation is as follows: the formed glass is cooled to 500°C at a rate of 1°C / min, maintained for 1 hour, and then cooled to room temperature at a rate of 0.5°C / min.

[0043] Example 2

[0044] A high-strength high-borosilicate glass comprises the following raw materials in parts by weight:

[0045] 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 parts of yttrium oxide, 0.7 parts of calcium oxide, 5 parts of sodium oxide and 1.5 parts of composite additives;

[0046] Wherein, the composite adjuvant is specifically prepared by the following steps:

[0047] Zirconium salt, other metal salts and calcium nitrate are added to deionized water and stirred at 60 rpm at room temperature until uniform. Then, acid solution is added to the system, the pH value of the system is adjusted to 4, the system temperature is increased to 70°C and stirred at 30 rpm for 2 hours, and then allowed to stand for gelation for 25 hours and dried at 90°C for 17 hours to obtain a composite auxiliary agent; wherein the molar ratio of zirconium salt, other metal salt and calcium nitrate is 0.5:0.5:4; wherein the zirconium salt is ZrO(NO3)2, and the other metal salt is zinc nitrate.

[0048] The method for preparing the high borosilicate glass comprises the following steps:

[0049] 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;

[0050] S2, high-temperature melting: The mixed material obtained in step S1 is transferred to a glass melting furnace and subjected to a melting heat treatment process to obtain a glass melt; wherein the specific operations of the melting heat treatment process are as follows:

[0051] The mixture obtained in step S1 was heated to 850°C at a heating rate of 20°C / min and held for 1.5 hours; then the temperature was further increased to 1250°C at a heating rate of 15°C / min and held for 30 minutes; then the temperature was increased to 1680°C at a heating rate of 15°C / min and held for 2 hours;

[0052] S3, molding process: homogenizing and clarifying the molten glass obtained in step S2, and then pressing and molding it to obtain molded glass; during the process, the temperature of the molten glass is set to 1450°C (cooling rate is 10°C / min) and maintained for 0.5 hours for homogenization; then, the system temperature is cooled to 1350°C at a rate of 15°C / min and allowed to stand for 0.5 hours for clarification; during the process, the pressing molding temperature is set to 1000°C and the pressing pressure is set to 20 MPa;

[0053] S4, placing the formed glass obtained in step S3 in an annealing furnace for annealing to obtain a high-strength high-borosilicate glass;

[0054] During the annealing process, the specific operation is as follows: the formed glass is cooled to 550°C at a rate of 3°C / min, maintained for 1.5 hours, and then cooled to room temperature at a rate of 1°C / min.

[0055] Example 3

[0056] A high-strength high-borosilicate glass comprises the following raw materials in parts by weight:

[0057] 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 composite additives;

[0058] Wherein, the composite adjuvant is specifically prepared by the following steps:

[0059] Zirconium salt, other metal salts and calcium nitrate are added to deionized water and stirred at 90 rpm at room temperature until uniform. Then, acid solution is added to the system, the pH value of the system is adjusted to 5, and then the system temperature is increased to 80°C and stirred at 90 rpm for 3 hours. Then, the system is allowed to stand for gelation for 30 hours and then dried at 100°C for 20 hours to obtain a composite auxiliary agent; wherein the molar ratio of the zirconium salt, other metal salts and calcium nitrate is 1:1:5; wherein the zirconium salt is ZrO(NO3)2, and the other metal salt is magnesium nitrate.

[0060] The method for preparing the high borosilicate glass comprises the following steps:

[0061] 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;

[0062] S2, high-temperature melting: The mixed material obtained in step S1 is transferred to a glass melting furnace and subjected to a melting heat treatment process to obtain a glass melt; wherein the specific operations of the melting heat treatment process are as follows:

[0063] The mixture obtained in step S1 was heated to 900°C at a heating rate of 20°C / min and held for 2 hours; then the temperature was further increased to 1300°C at a heating rate of 20°C / min and held for 40 minutes; then the temperature was increased to 1700°C at a heating rate of 20°C / min and held for 2 hours;

[0064] S3, molding process: homogenizing and clarifying the molten glass obtained in step S2, and then pressing and molding it to obtain molded glass; during the process, the temperature of the molten glass is set to 1500°C (cooling rate is 10°C / min) and maintained for 1 hour for homogenization; then the system temperature is cooled to 1400°C at a rate of 20°C / min and allowed to stand for 1 hour for clarification; during the process, the pressing molding temperature is set to 1100°C and the pressing pressure is set to 30 MPa;

[0065] S4, placing the formed glass obtained in step S3 in an annealing furnace for annealing to obtain a high-strength high-borosilicate glass;

[0066] During the annealing process, the specific operation is as follows: the formed glass is cooled to 600°C at a rate of 5°C / min, maintained for 2 hours, and then cooled to room temperature at a rate of 2°C / min.

[0067] Comparative Example 1

[0068] The difference between this comparative example and Example 1 is that no yttrium oxide component is added in this comparative example; specifically, a high-strength high-borosilicate glass comprises the following raw materials in parts by weight:

[0069] 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 parts of calcium oxide, 4 parts of sodium oxide and 0.5 parts of composite additives.

[0070] Comparative Example 2

[0071] 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 comprises the following raw materials in parts by mass:

[0072] 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 parts of calcium oxide, 2 parts of yttrium oxide, 4 parts of sodium oxide and 0.5 parts of composite additives.

[0073] Comparative Example 3

[0074] The difference between this comparative example and Example 1 is that the composite auxiliary agent is obtained by mixing zirconium salt, other metal salts and calcium nitrate in a molar ratio of 0.1:0.1:3.

[0075] Comparative Example 4

[0076] The difference between this comparative example and Example 1 is that in step S2, the melt heat treatment does not set the first heat treatment gradient, specifically:

[0077] The specific operation of the melt heat treatment process is:

[0078] The mixture obtained in step S1 was further heated to 1200° C. at a heating rate of 10° C. / min and maintained for 20 minutes, and then heated to 1650° C. at a heating rate of 10° C. / min and maintained for 2 hours.

[0079] Comparative Example 5

[0080] The difference between this comparative example and Example 1 is that in step S2, the melt heat treatment does not have a second heat treatment gradient. Specifically, the specific operation of the melt heat treatment process is as follows:

[0081] The mixture obtained in step S1 was heated to 800°C at a heating rate of 15°C / min and maintained for 1 hour; then the temperature was increased to 1650°C at a heating rate of 10°C / min and maintained for 2 hours.

[0082] Performance Testing

[0083] The high borosilicate glass samples obtained in Examples 1-3 and Comparative Examples 1-5 of the present application were prepared into samples with a thickness of 5 mm, and performance tests were performed on the samples in each group.

[0084] The product's linear thermal expansion coefficient (20-300°C) was tested according to the test method in GB / T 34843-2017, and the shear modulus and elastic modulus were tested according to the test method in GB / T 37780-2019. The sample's bubble content was tested according to the method in GB / T7962.8-2010.

[0085] Among them, the bubble degree grade is determined by the total cross-sectional area of ​​bubbles in the glass (mm 2 / 100cm 2 ) range, specifically divided into the following seven levels:

[0086] A00 grade: 0.003-0.01

[0087] A0 level: 0.01-0.03

[0088] Grade A: 0.03-0.10

[0089] Grade B: 0.10-0.25

[0090] C-grade: 0.25-0.50

[0091] D-level: 0.50-1.00

[0092] E grade: greater than 1.00

[0093] The specific test results are shown in Table 1 below.

[0094] Table 1

[0095]

[0096] The results shown in Table 1 above show 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. The results of Comparative Examples 1 and 2 show that an appropriate amount of yttrium oxide can improve the performance of high borosilicate glass, including elastic modulus and linear expansion coefficient. However, when the yttrium oxide content increases, the Y 3+ The ionic field is too strong, forcing the bridging oxygen to become non-bridging oxygen and arrange in Y 3+The surroundings disrupt the structure of the boron-oxygen tetrahedrons in the borosilicate glass system, causing the boron-oxygen tetrahedron content to be higher than the boron-oxygen triangular structure. This reduces the viscosity of the glass melt, the material's glass-forming properties, and all aspects of the product's performance. The results in Comparative Examples 3-5 demonstrate that the composite additives derived from zirconium salts, other metal salts, and calcium nitrate, combined with the heat treatment process described in this solution, can improve the quality of the glass melt and the performance of borosilicate glass products.

[0097] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0098] 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 described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A high-strength borosilicate glass, characterized in that: The invention comprises the following raw materials in parts 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 a composite auxiliary agent; wherein the composite auxiliary agent is composed of zirconium salt, other metal salts and calcium nitrate; The other metal salt in the composite additive is at least one of potassium salt, zinc salt, and magnesium salt; the composite additive is specifically prepared by the following steps: adding zirconium salt, other metal salts, and calcium nitrate to deionized water, stirring at room temperature until uniform, adjusting the pH value of the system to 4-5, raising the system temperature to 70-80° C. and stirring for 2-3 hours, then standing and gelling for 20-30 hours and then drying to obtain the composite additive; wherein the molar ratio of zirconium salt, other metal salt, and calcium nitrate is (0.1-1):(0.1-1):(3-5); The preparation method of high-strength high-borosilicate glass specifically includes the following preparation steps: S1, raw material mixing: quartz sand, borax, boric acid, aluminum hydroxide, sodium chloride, yttrium oxide, calcium oxide, sodium oxide and composite additives in the formula are evenly mixed to obtain a mixture; S2, high-temperature melting: the mixture obtained in step S1 is transferred to a glass melting furnace, and after a melting heat treatment process, a glass melt is obtained; the specific operation of the melting 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 continuously increased to 1200-1300°C at a heating rate of 10-20°C / min, and maintained for 20-4 0 minutes, then raise the temperature to 1650-1700°C at a heating rate of 10-20°C / min, and maintain for 2 hours; S3, molding treatment: homogenize and clarify the glass melt obtained in step S2, and press-form after cooling to obtain molded glass; the specific operations of homogenization and clarification treatment are: set the temperature of the glass melt to 1400-1500°C, maintain for 0.5-1 hour to perform homogenization treatment; then cool the system temperature to 1300-1400°C at a rate of 10-20°C / min, stand for 0.5-1 hour to perform clarification treatment; S4, place the molded glass obtained in step S3 in an annealing furnace for annealing treatment to obtain a high-strength high-borosilicate glass.

2. A method for preparing high-strength borosilicate glass as claimed in claim 1, characterized in that: The preparation process specifically includes the following steps: S1, raw material mixing: uniformly mixing the formulated quantities of quartz sand, borax, boric acid, aluminum hydroxide, sodium chloride, yttrium oxide, calcium oxide, sodium oxide and composite additives 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; the specific operation of the melting heat treatment process is: heating the mixture obtained in step S1 to 800-900°C at a heating rate of 15-20°C / min, and maintaining the temperature for 1- 2 hours; then continue to increase the temperature to 1200-1300°C at a heating rate of 10-20°C / min, maintain for 20-40 minutes, then increase the temperature to 1650-1700°C at a heating rate of 10-20°C / min, maintain for 2 hours; S3, molding treatment: homogenize and clarify the glass melt obtained in step S2, and press into shape after cooling to obtain molded glass; S4, place the molded glass obtained in step S3 in an annealing furnace for annealing treatment to obtain a high-strength high-borosilicate glass.

3. The method for preparing high-strength borosilicate glass according to claim 2, wherein: In step S3, the pressing temperature is 1000-1100° C., and the pressing pressure is 10-30 MPa.

4. The method for preparing high-strength borosilicate glass according to claim 2, wherein: In step S4, the specific operation of the annealing treatment is: reducing the temperature of the formed glass to 500-600°C at a rate of 1-5°C / min, keeping it for 1-2 hours, and then cooling it to room temperature at a rate of 0.5-2°C / min.

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