A high-toughness ultrathin flexible glass and its preparation method

Abstract

This invention discloses a high-toughness ultrathin flexible glass and its preparation method, relating to the field of glass manufacturing technology. The raw materials for the ultrathin flexible glass include silicon dioxide, alumina, lithium oxide, sodium oxide, magnesium oxide, a modified nano-reinforcing phase, a high-temperature melt modifier, and cerium dioxide. The modified nano-reinforcing phase is prepared by pretreating silicon carbide and silicon nitride with hydrochloric acid, then mixing them with nano-zirconia to obtain a mixture; the mixture is then modified with a silane coupling agent to obtain the modified nano-reinforcing phase. The high-temperature melt modifier is a mixture of lithium borate, sodium sulfate, and lithium fluoride. The preparation method of the ultrathin flexible glass includes the steps of preparing the modified nano-reinforcing phase, homogenizing glass melt, forming a glass substrate, and obtaining the ultrathin flexible glass. The ultrathin flexible glass prepared by this invention exhibits high fracture toughness and structural stiffness, excellent flexibility and flexural fatigue durability, and excellent thermal shock resistance.

Description

Technical Field

[0001] This invention relates to the field of glass manufacturing technology, specifically to a high-toughness ultrathin flexible glass and its preparation method. Background Technology

[0002] Ultra-thin flexible glass, with its combination of thinness and excellent light transmittance, has become a core substrate for emerging fields such as flexible displays, wearable smart devices, and flexible energy storage devices. The market demands increasingly stringent requirements for its comprehensive mechanical properties and environmental adaptability.

[0003] Existing ultrathin flexible glass is mostly developed based on traditional soda-lime-silicon or aluminosilicate glass systems. Although basic flexibility can be achieved by reducing the thickness, it generally suffers from performance shortcomings: insufficient fracture toughness, poor bending fatigue durability, and inadequate thermal shock resistance. In addition, some improvement technologies attempt to introduce nano-reinforcing phases to improve toughness, but because nanoparticles are unevenly dispersed in the glass matrix, they are prone to local stress concentration, which exacerbates structural defects and cannot fundamentally solve the technical challenge of synergistically improving the aforementioned multiple properties.

[0004] Prior art disclosed in CN119080394A is an ultrathin flexible glass and its preparation method and application. This prior art relies solely on ZrO2 and TiO2 as auxiliary components. The nanoparticles are prone to agglomeration and have weak interfacial bonding with the glass matrix, resulting in poor crack propagation resistance. Furthermore, the chemical tempering uses pure KNO3 molten salt, which has low potassium ion diffusion efficiency and limited ion exchange strengthening effect. Prior art disclosed in CN120117834B is also an ultrathin flexible glass and its preparation method. In this prior art, the composite toughening agent has poor compatibility with the glass matrix, leading to insufficient fracture toughness and bending fatigue performance. In addition, the annealing process is not clearly defined, resulting in significant residual thermal stress within the glass.

[0005] In summary, although the existing technical solutions have improved some properties of ultrathin flexible glass to a certain extent, the following technical problems still exist: insufficient fracture toughness and structural stiffness, poor flexibility and bending fatigue durability, and poor thermal shock resistance. Summary of the Invention

[0006] In order to solve the above-mentioned problems in the prior art, the present invention provides a high-toughness ultrathin flexible glass and its preparation method, and achieves the following objectives: to prepare an ultrathin flexible glass with high fracture toughness and structural stiffness, excellent flexibility and bending fatigue durability, and excellent thermal shock resistance.

[0007] To achieve the above objectives, the following technical solution is adopted:

[0008] A high-toughness ultrathin flexible glass, by weight, comprises the following raw materials: 60-70 parts silicon dioxide, 12-16 parts aluminum oxide, 1-3 parts lithium oxide, 10-14 parts sodium oxide, 2-4 parts magnesium oxide, 1.5-2.5 parts modified nano-reinforcing phase, 2-3 parts high-temperature melt modifier, and 0.5-0.8 parts cerium dioxide.

[0009] The modified nano-reinforcing phase is obtained by pretreating silicon carbide and silicon nitride with hydrochloric acid and then mixing them with nano-zirconia. The mixture is then modified with a silane coupling agent to obtain the modified nano-reinforcing phase.

[0010] The high-temperature melt modifier is a mixture of lithium borate, sodium sulfate, and lithium fluoride, with a mass ratio of (10-15):(8-12):(1-2).

[0011] This invention also provides a method for preparing high-toughness ultrathin flexible glass, comprising the following steps:

[0012] Step 1: Preparation of modified nano-reinforced phase

[0013] Dissolve the silane coupling agent in an ethanol-water mixed solvent, adjust the pH to 4-5 with acetic acid, stir for 10-15 minutes at a speed of 200-300 rpm, and obtain a coupling agent hydrolysate with a mass fraction of 0.3-0.5%.

[0014] Silicon carbide and silicon nitride were immersed in dilute hydrochloric acid and heated to 80-85℃ for 2.5-3 hours. After the reaction was completed, the precipitates were separated and washed with deionized water until neutral. Then they were dried at 60-70℃ for 4-5 hours to obtain pretreated silicon carbide and pretreated silicon nitride.

[0015] Nano-zirconia, pretreated silicon carbide, and pretreated silicon nitride are mixed evenly to obtain a mixture. The mass ratio of nano-zirconia, pretreated silicon carbide, and pretreated silicon nitride is (5-10):(2-3):(4-6).

[0016] The mixture is added to the coupling agent hydrolysate at a mass ratio of (10-15):1. The temperature is controlled at 30-50℃, and stirring is started at 200-300 rpm for 2-3 hours. Simultaneously, ultrasonic dispersion is assisted at a power of 200-300W, with ultrasonication for 10 minutes every 30 minutes. After the reaction, centrifugation is performed at 8000-10000 rpm for 15-20 minutes, and the precipitate is collected as the modified nanoparticles. The modified nanoparticles are washed 2-3 times with anhydrous ethanol and then dried at 60-80℃ for 3-5 hours to obtain the modified nano-reinforced phase. The silane coupling agent used is KH570; the ethanol-water mixed solvent is a mixture of ethanol and deionized water at a mass ratio of 9:1; the dilute hydrochloric acid is a 10% hydrochloric acid solution.

[0017] Step 2: Homogenization of glass melting

[0018] Lithium borate, sodium sulfate, and lithium fluoride were mixed evenly in a mass ratio of (10-15):(8-12):(1-2) to obtain a high-temperature melt modifier.

[0019] Silica, alumina, lithium oxide, sodium oxide, magnesium oxide, modified nano-reinforcing phase, high-temperature melt modifier, and cerium dioxide are mixed evenly and then added to a glass heating furnace. The heating rate is 5-8℃ / min, and the temperature is raised to 500-550℃ and held for 1-1.5 hours. After the holding period, the temperature is raised again at a rate of 3-5℃ / min to 1550-1650℃ and held for 5-8 hours. Then, stirring is started, and the mixture is held and stirred for 1-2 hours at a speed of 100-200 rpm to obtain a glass melt.

[0020] Step 3: Glass substrate molding

[0021] The molten glass is introduced into an overflow tank at a temperature of 1250-1350℃. The melt overflows from both sides of the overflow tank and flows downward along the tank wall under gravity, converging at the bottom to form a continuous glass ribbon. The temperature is then slowly reduced to 500-550℃ at a rate of 5-10℃ / min. The glass ribbon is then sent to an annealing furnace for annealing. It is first held at 500-550℃ for 2-3 hours. After the holding period, the temperature is reduced to 300-350℃ at a rate of 1-2℃ / min, and then reduced to room temperature at a rate of 5-8℃ / min to obtain an ultrathin glass substrate.

[0022] Step 4: Obtaining ultrathin flexible glass

[0023] Potassium nitrate and potassium chloride are mixed evenly and heated to 350-420℃ to obtain a mixed molten salt with a mass ratio of potassium nitrate to potassium chloride of (17-18):(2-3). The ultrathin glass substrate is immersed in the mixed molten salt for ion exchange at a temperature of 350-420℃ for 2-4 hours. After the exchange is completed, the substrate is washed with deionized water to remove residual molten salt and then slowly cooled to room temperature at a rate of 5-10℃ / min. The substrate is then dried at a temperature of 100-120℃ for 30-40 minutes to obtain ultrathin flexible glass.

[0024] The beneficial effects of this invention are as follows:

[0025] (1) The ultrathin flexible glass of this invention exhibits excellent fracture toughness and structural stiffness. The fracture toughness of the prepared ultrathin flexible glass is 1.29-1.37 MPa·m. 1 / 2 Its elastic modulus reaches 83-86 GPa.

[0026] (2) The ultra-thin flexible glass of the present invention has excellent flexibility and bending fatigue durability. The ultra-thin flexible glass prepared has an ultimate bending radius of 1.8-2.1 mm and a maximum number of bending cycles of 360,000-390,000.

[0027] (3) The ultra-thin flexible glass of the present invention has excellent thermal shock resistance. The prepared ultra-thin flexible glass does not crack after being subjected to 48-52 cycles of alternating hot and cold immersion. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0029] Example 1: A high-toughness ultrathin flexible glass and its preparation method

[0030] A high-toughness ultrathin flexible glass, by weight, is composed of the following raw materials: 60 parts silicon dioxide, 16 parts aluminum oxide, 3 parts lithium oxide, 14 parts sodium oxide, 4 parts magnesium oxide, 1.5 parts modified nano-reinforcing phase, 2 parts high-temperature melt modifier, and 0.5 parts cerium dioxide.

[0031] The high-temperature melt modifier is a mixture of lithium borate, sodium sulfate, and lithium fluoride, with a mass ratio of lithium borate, sodium sulfate, and lithium fluoride of 10:8:1.

[0032] A method for preparing high-toughness ultrathin flexible glass includes the following steps:

[0033] Step 1: Preparation of modified nano-reinforced phase

[0034] The silane coupling agent was dissolved in an ethanol-water mixed solvent, the pH was adjusted to 4 with acetic acid, and the mixture was stirred for 10 min at a speed of 300 rpm to obtain a coupling agent hydrolysate with a mass fraction of 0.3%.

[0035] Silicon carbide and silicon nitride were immersed in dilute hydrochloric acid, heated to 80°C, and reacted for 3 hours. After the reaction was completed, the precipitates were separated and washed with deionized water until neutral. Then, they were dried at 60°C for 5 hours to obtain pretreated silicon carbide and pretreated silicon nitride.

[0036] Nano-zirconia, pretreated silicon carbide, and pretreated silicon nitride are mixed evenly to obtain a mixture with a mass ratio of 5:2:4.

[0037] The mixture was added to the coupling agent hydrolysate at a mass ratio of 10:1. The temperature was controlled at 30°C, and stirring was started at 200 rpm for 3 hours. Simultaneously, ultrasonic dispersion was assisted at a power of 200W, with ultrasonication for 10 minutes every 30 minutes. After the reaction, centrifugation was performed at 8000 rpm for 20 minutes, and the precipitate was collected, which was the modified nanoparticle. The modified nanoparticle was washed twice with anhydrous ethanol and then dried at 60°C for 5 hours to obtain the modified nano-reinforced phase. The silane coupling agent used was KH570; the ethanol-water mixed solvent was a mixture of ethanol and deionized water at a mass ratio of 9:1; the dilute hydrochloric acid was a 10% hydrochloric acid solution; the nano-zirconia had a particle size of 30-50 nm; the silicon carbide had a particle size of 50-100 nm; and the silicon nitride had a particle size of 80-150 nm.

[0038] Step 2: Homogenization of glass melting

[0039] Lithium borate, sodium sulfate, and lithium fluoride were mixed evenly in a mass ratio of 10:8:1 to obtain a high-temperature melt modifier.

[0040] Silica, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, modified nano-reinforcing phase, high-temperature melt modifier, and cerium dioxide were mixed evenly and then added to a glass heating furnace. The temperature was increased to 500℃ at a rate of 5℃ / min and held for 1.5h. After holding, the temperature was increased to 1550℃ at a rate of 3℃ / min and held for 8h. Then, stirring was started, and the mixture was held and stirred for 2h at a speed of 100rpm to obtain glass melt.

[0041] Step 3: Glass substrate molding

[0042] The molten glass is introduced into an overflow tank at a temperature of 1250°C. The melt overflows from both sides of the overflow tank and flows downward along the tank wall under gravity, converging at the bottom to form a continuous glass ribbon. The temperature is then slowly reduced to 500°C at a rate of 10°C / min. The glass ribbon is then sent to an annealing furnace for annealing treatment, first held at 500°C for 2 hours. After the holding period, the temperature is reduced to 300°C at a rate of 2°C / min, and then reduced to room temperature at a rate of 5°C / min to obtain an ultrathin glass substrate.

[0043] Step 4: Obtaining ultrathin flexible glass

[0044] Potassium nitrate and potassium chloride were mixed evenly and heated to 350°C to obtain a mixed molten salt with a mass ratio of potassium nitrate to potassium chloride of 17:2. The ultrathin glass substrate was immersed in the mixed molten salt for ion exchange at 350°C for 4 hours. After the exchange was completed, the substrate was washed with deionized water to remove residual molten salt and then slowly cooled to room temperature at a rate of 5°C / min. The substrate was then dried at 100°C for 40 minutes to obtain ultrathin flexible glass.

[0045] Example 2: A high-toughness ultrathin flexible glass and its preparation method

[0046] A high-toughness ultrathin flexible glass, by weight, is composed of the following raw materials: 65 parts silicon dioxide, 14 parts aluminum oxide, 2 parts lithium oxide, 12 parts sodium oxide, 3 parts magnesium oxide, 2 parts modified nano-reinforcing phase, 3 parts high-temperature melt modifier, and 0.8 parts cerium dioxide.

[0047] The high-temperature melt modifier is a mixture of lithium borate, sodium sulfate, and lithium fluoride, with a mass ratio of lithium borate, sodium sulfate, and lithium fluoride of 12:10:1.5.

[0048] A method for preparing high-toughness ultrathin flexible glass includes the following steps:

[0049] Step 1: Preparation of modified nano-reinforced phase

[0050] The silane coupling agent was dissolved in an ethanol-water mixed solvent, the pH was adjusted to 4.5 with acetic acid, and the mixture was stirred for 15 minutes at a speed of 300 rpm to obtain a coupling agent hydrolysate with a mass fraction of 0.4%.

[0051] Silicon carbide and silicon nitride were immersed in dilute hydrochloric acid, heated to 85°C, and reacted for 3 hours. After the reaction was completed, the precipitates were separated and washed with deionized water until neutral. Then they were dried at 70°C for 5 hours to obtain pretreated silicon carbide and pretreated silicon nitride.

[0052] Nano-zirconia, pretreated silicon carbide, and pretreated silicon nitride are mixed evenly to obtain a mixture with a mass ratio of 8:2.5:5.

[0053] The mixture was added to the coupling agent hydrolysate at a mass ratio of 12:1. The temperature was controlled at 40℃, and stirring was started at 300 rpm for 3 hours. Simultaneously, ultrasonic dispersion was assisted at a power of 300W, with ultrasonication for 10 minutes every 30 minutes. After the reaction, centrifugation was performed at 9000 rpm for 20 minutes, and the precipitate was collected, which was the modified nanoparticle. The modified nanoparticle was washed three times with anhydrous ethanol and then dried at 70℃ for 4 hours to obtain the modified nano-reinforcing phase. The silane coupling agent used was KH570; the ethanol-water mixed solvent was a mixture of ethanol and deionized water at a mass ratio of 9:1; the dilute hydrochloric acid was a 10% hydrochloric acid solution; the nano-zirconia had a particle size of 30-50 nm; the silicon carbide had a particle size of 50-100 nm; and the silicon nitride had a particle size of 80-150 nm.

[0054] Step 2: Homogenization of glass melting

[0055] Lithium borate, sodium sulfate, and lithium fluoride were mixed evenly in a mass ratio of 12:10:1.5 to obtain a high-temperature melt modifier.

[0056] Silica, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, modified nano-reinforcing phase, high-temperature melt modifier, and cerium dioxide were mixed evenly and then added to a glass heating furnace. The temperature was increased to 530℃ at a rate of 6℃ / min and held for 1.5h. After holding, the temperature was increased to 1600℃ at a rate of 4℃ / min and held for 7h. Then, stirring was started, and the mixture was held and stirred for 2h at a speed of 200rpm to obtain glass melt.

[0057] Step 3: Glass substrate molding

[0058] The molten glass is introduced into an overflow tank at a temperature of 1300℃. The melt overflows from both sides of the overflow tank and flows downward along the tank wall under gravity, converging at the bottom to form a continuous glass ribbon. The temperature is then slowly reduced to 530℃ at a rate of 8℃ / min. The glass ribbon is then sent to an annealing furnace for annealing treatment, first held at 530℃ for 3 hours. After the holding period, the temperature is reduced to 300℃ at a rate of 2℃ / min, and then reduced to room temperature at a rate of 8℃ / min to obtain an ultrathin glass substrate.

[0059] Step 4: Obtaining ultrathin flexible glass

[0060] Potassium nitrate and potassium chloride were mixed evenly and heated to 400℃ to obtain a mixed molten salt with a mass ratio of potassium nitrate to potassium chloride of 18:3. The ultrathin glass substrate was immersed in the mixed molten salt for ion exchange at 400℃ for 4 hours. After the exchange was completed, the substrate was washed with deionized water to remove residual molten salt and then slowly cooled to room temperature at a rate of 8℃ / min. The substrate was then dried at 110℃ for 40 minutes to obtain ultrathin flexible glass.

[0061] Example 3: A high-toughness ultrathin flexible glass and its preparation method

[0062] A high-toughness ultrathin flexible glass, by weight, is composed of the following raw materials: 70 parts silicon dioxide, 12 parts aluminum oxide, 1 part lithium oxide, 10 parts sodium oxide, 2 parts magnesium oxide, 2.5 parts modified nano-reinforcing phase, 3 parts high-temperature melt modifier, and 0.8 parts cerium dioxide.

[0063] The high-temperature melt modifier is a mixture of lithium borate, sodium sulfate, and lithium fluoride, with a mass ratio of lithium borate, sodium sulfate, and lithium fluoride of 15:12:2.

[0064] A method for preparing high-toughness ultrathin flexible glass includes the following steps:

[0065] Step 1: Preparation of modified nano-reinforced phase

[0066] The silane coupling agent was dissolved in an ethanol-water mixed solvent, the pH was adjusted to 5 with acetic acid, and the mixture was stirred for 15 minutes at a speed of 200 rpm to obtain a coupling agent hydrolysate with a mass fraction of 0.5%.

[0067] Silicon carbide and silicon nitride were immersed in dilute hydrochloric acid, heated to 85°C, and reacted for 2.5 hours. After the reaction was completed, the precipitates were separated and washed with deionized water until neutral. Then they were dried at 70°C for 4 hours to obtain pretreated silicon carbide and pretreated silicon nitride.

[0068] Nano-zirconia, pretreated silicon carbide, and pretreated silicon nitride are mixed evenly to obtain a mixture with a mass ratio of 10:3:6.

[0069] The mixture was added to the coupling agent hydrolysate at a mass ratio of 15:1. The temperature was controlled at 50°C, and stirring was started at 300 rpm for 2 hours. Simultaneously, ultrasonic dispersion was assisted at a power of 300W, with ultrasonication for 10 minutes every 30 minutes. After the reaction, centrifugation was performed at 10,000 rpm for 15 minutes, and the precipitate was collected, which was the modified nanoparticle. The modified nanoparticle was washed three times with anhydrous ethanol and then dried at 80°C for 3 hours to obtain the modified nano-reinforced phase. The silane coupling agent used was KH570; the ethanol-water mixed solvent was a mixture of ethanol and deionized water at a mass ratio of 9:1; the dilute hydrochloric acid was a 10% hydrochloric acid solution; the nano-zirconia had a particle size of 30-50 nm; the silicon carbide had a particle size of 50-100 nm; and the silicon nitride had a particle size of 80-150 nm.

[0070] Step 2: Homogenization of glass melting

[0071] Lithium borate, sodium sulfate, and lithium fluoride were mixed evenly in a mass ratio of 15:12:2 to obtain a high-temperature melt modifier.

[0072] Silica, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, modified nano-reinforcing phase, high-temperature melt modifier, and cerium dioxide were mixed evenly and then added to a glass heating furnace. The temperature was increased to 550℃ at a rate of 8℃ / min and held for 1 hour. After holding, the temperature was increased to 1650℃ at a rate of 5℃ / min and held for 5 hours. Then, stirring was started, and the mixture was kept at 200 rpm for 1 hour to obtain a glass melt.

[0073] Step 3: Glass substrate molding

[0074] The molten glass is introduced into an overflow tank at a temperature of 1350℃. The melt overflows from both sides of the overflow tank and flows downward along the tank wall under gravity, converging at the bottom to form a continuous glass ribbon. The temperature is then slowly reduced to 550℃ at a rate of 5℃ / min. The glass ribbon is then sent to an annealing furnace for annealing treatment, first held at 550℃ for 3 hours. After the holding period, the temperature is reduced to 350℃ at a rate of 1℃ / min, and then reduced to room temperature at a rate of 8℃ / min to obtain an ultrathin glass substrate.

[0075] Step 4: Obtaining ultrathin flexible glass

[0076] Potassium nitrate and potassium chloride were mixed evenly and heated to 420℃ to obtain a mixed molten salt with a mass ratio of potassium nitrate to potassium chloride of 18:3. The ultrathin glass substrate was immersed in the mixed molten salt for ion exchange at 420℃ for 2 hours. After the exchange was completed, the substrate was washed with deionized water to remove residual molten salt and then slowly cooled to room temperature at a rate of 10℃ / min. The substrate was then dried at 120℃ for 30 minutes to obtain ultrathin flexible glass.

[0077] Comparative Example 1

[0078] An ultrathin flexible glass, by weight, is composed of the following raw materials: 65 parts silicon dioxide, 14 parts aluminum oxide, 2 parts lithium oxide, 12 parts sodium oxide, 3 parts magnesium oxide, 3 parts high-temperature melting modifier, and 0.8 parts cerium dioxide.

[0079] The high-temperature melt modifier is a mixture of lithium borate, sodium sulfate, and lithium fluoride, with a mass ratio of lithium borate, sodium sulfate, and lithium fluoride of 12:10:1.5.

[0080] A method for preparing ultrathin flexible glass includes the following steps:

[0081] Step 1: Homogenization of glass melting

[0082] Lithium borate, sodium sulfate, and lithium fluoride were mixed evenly in a mass ratio of 12:10:1.5 to obtain a high-temperature melt modifier.

[0083] Silica, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, high-temperature melt modifier, and cerium dioxide were mixed evenly and then added to a glass heating furnace. The temperature was increased to 530°C at a rate of 6°C / min and held for 1.5 hours. After holding, the temperature was increased to 1600°C at a rate of 4°C / min and held for 7 hours. Then, stirring was started, and the mixture was held and stirred for 2 hours at a speed of 200 rpm to obtain the glass melt.

[0084] Step 2: Glass substrate molding

[0085] This step is the same as the "glass substrate forming" step in Example 2.

[0086] Step 3: Obtaining ultrathin flexible glass

[0087] This step is the same as the "Preparation of Ultrathin Flexible Glass" step in Example 2.

[0088] Comparative Example 2

[0089] An ultrathin flexible glass, by weight, is composed of the following raw materials: 65 parts silicon dioxide, 14 parts aluminum oxide, 2 parts lithium oxide, 12 parts sodium oxide, 3 parts magnesium oxide, 2 parts modified nano-reinforcing phase, and 0.8 parts cerium dioxide.

[0090] A method for preparing ultrathin flexible glass includes the following steps:

[0091] Step 1: Preparation of modified nano-reinforced phase

[0092] This step is the same as the "Preparation of Modified Nano-Reinforcing Phase" step in Example 2.

[0093] Step 2: Homogenization of glass melting

[0094] Lithium borate, sodium sulfate, and lithium fluoride were mixed evenly in a mass ratio of 12:10:1.5 to obtain a high-temperature melt modifier.

[0095] Silica, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, modified nano-reinforcing phase, and cerium dioxide were mixed evenly and then added to a glass heating furnace. The temperature was increased to 530℃ at a rate of 6℃ / min and held for 1.5h. After the holding period, the temperature was increased to 1600℃ at a rate of 4℃ / min and held for 7h. Then, stirring was started, and the mixture was stirred and held for 2h at a speed of 200rpm to obtain a glass melt.

[0096] Step 3: Glass substrate molding

[0097] This step is the same as the "glass substrate forming" step in Example 2.

[0098] Step 4: Obtaining ultrathin flexible glass

[0099] This step is the same as the "Preparation of Ultrathin Flexible Glass" step in Example 2.

[0100] Example 4 Performance Testing

[0101] (a) The fracture toughness of the ultrathin flexible glass prepared in Examples 1-3 and Comparative Examples 1-2 was tested according to the test method specified in GB / T 37900-2019. The specimen size was a square specimen with a side length of 40 mm and a thickness of 1 mm. The elastic modulus was tested according to the test method specified in GB / T37780-2019. The specific test results are shown in Table 1.

[0102] Table 1

[0103]

[0104] As shown in Table 1, the fracture toughness of the ultrathin flexible glass prepared in Examples 1-3 is 1.29-1.37 MPa·m. 1 / 2 The elastic modulus reaches 83-86 GPa. This demonstrates that the ultrathin flexible glass prepared by this invention possesses excellent fracture toughness and structural stiffness.

[0105] (II) The ultimate bending radius of the ultrathin flexible glass prepared in Examples 1-3 and Comparative Examples 1-2 was tested according to the test method specified in GB / T 38686-2020. Bending fatigue testing was carried out using a bending fatigue testing machine. After the sample reached the bending radius, it was moved back to the starting position to complete one bending fatigue test. The cycle frequency was set to 30 times / min, and the maximum number of bends was recorded. The specific test results are shown in Table 2.

[0106] Table 2

[0107]

[0108] As shown in Table 2, the ultrathin flexible glass prepared in Examples 1-3 has an ultimate bending radius of 1.8-2.1 mm and a maximum bending cycle of 360,000-390,000 times. This demonstrates that the ultrathin flexible glass prepared by this invention possesses excellent flexibility and bending fatigue durability.

[0109] (III) Thermal shock resistance tests were conducted on the ultrathin flexible glass prepared in Examples 1-3 and Comparative Examples 1-2. The glass samples were alternately immersed in cold water at 20±5℃ and hot water at 500±5℃, each time for 10 minutes, and the maximum number of cycles without cracking was recorded. The specific test results are shown in Table 3.

[0110] Table 3

[0111]

[0112] As shown in Table 3, the ultrathin flexible glass prepared in Examples 1-3 did not exhibit any cracks after 48-52 cycles of alternating hot and cold immersion. This demonstrates that the ultrathin flexible glass prepared by this invention possesses excellent thermal shock resistance.

[0113] Obviously, there are many other possible implementation methods under the concept of this invention. It should be stated here that any changes made under the inventive concept of this invention will fall within the protection scope of this invention.

Claims

1. A high-toughness, ultra-thin flexible glass, characterized in that: The raw material weight ratio of the ultrathin flexible glass is as follows: 60-70 parts silicon dioxide, 12-16 parts aluminum oxide, 1-3 parts lithium oxide, 10-14 parts sodium oxide, 2-4 parts magnesium oxide, 1.5-2.5 parts modified nano-reinforcing phase, 2-3 parts high-temperature melt modifier, and 0.5-0.8 parts cerium dioxide. The modified nano-reinforcing phase is prepared as follows: silicon carbide and silicon nitride are immersed in dilute hydrochloric acid for hydrochloric acid pretreatment to obtain pretreated silicon carbide and pretreated silicon nitride; nano-zirconia, pretreated silicon carbide, and pretreated silicon nitride are mixed evenly to obtain a mixture; the mixture is added to a coupling agent hydrolysate, the temperature is controlled at 30-50℃, and the mixture is stirred for 2-3 hours while being ultrasonically dispersed; after the reaction is completed, the modified nano-reinforcing phase is obtained by centrifugation, washing, and drying. The high-temperature melt modifier is a mixture of lithium borate, sodium sulfate, and lithium fluoride; the mass ratio of lithium borate, sodium sulfate, and lithium fluoride is (10-15):(8-12):(1-2).

2. The high-toughness ultrathin flexible glass according to claim 1, characterized in that: The mass ratio of the nano-zirconia, pretreated silicon carbide, and pretreated silicon nitride is (5-10):(2-3):(4-6).

3. The high-toughness ultrathin flexible glass according to claim 1, characterized in that: The mass ratio of the coupling agent hydrolysate to the mixture is (10-15):1, and the coupling agent used in the coupling agent hydrolysate is silane coupling agent KH570.

4. The method for preparing a high-toughness ultrathin flexible glass according to any one of claims 1-3, characterized in that: The process includes steps such as preparing a modified nano-reinforcing phase, homogenizing glass melting, forming a glass substrate, and obtaining ultrathin flexible glass.

5. The method for preparing a high-toughness ultrathin flexible glass according to claim 4, characterized in that: The glass melting and homogenization process involves uniformly mixing silica, alumina, lithium oxide, sodium oxide, magnesium oxide, modified nano-reinforcing phase, high-temperature melt modifier, and cerium dioxide, then adding the mixture to a glass heating furnace and heating it to 500-550℃ for 1-1.5 hours. After the heating period, the temperature is further increased to 1550-1650℃ and held for 5-8 hours. Then, stirring is started, and the mixture is held at 100-200 rpm for 1-2 hours to obtain a glass melt.

6. The method for preparing a high-toughness ultrathin flexible glass according to claim 4, characterized in that: The glass substrate forming process involves introducing molten glass into an overflow tank at a temperature of 1250-1350℃. The melt overflows from both sides of the overflow tank and flows downward along the tank wall under gravity, converging at the bottom to form a continuous glass ribbon. The temperature is then slowly reduced to 500-550℃ at a rate of 5-10℃ / min. The glass ribbon is then placed in an annealing furnace for annealing, initially held at 500-550℃ for 2-3 hours. After the holding period, the temperature is slowly reduced to 300-350℃, and then further reduced to room temperature at a rate of 5-8℃ / min to obtain an ultrathin glass substrate.

7. The method for preparing a high-toughness ultrathin flexible glass according to claim 4, characterized in that: The process for obtaining ultrathin flexible glass involves: mixing potassium nitrate and potassium chloride evenly and heating the mixture to 350-420℃ to obtain a mixed molten salt; immersing the ultrathin glass substrate in the mixed molten salt for ion exchange at 350-420℃ for 2-4 hours; and washing and drying the substrate after the exchange to obtain ultrathin flexible glass.

8. The method for preparing a high-toughness ultrathin flexible glass according to claim 7, characterized in that: The mass ratio of potassium nitrate to potassium chloride is (17-18):(2-3).

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