A high-strength rare earth aluminosilicate glass and a preparation method thereof

Abstract

The present invention discloses a high-strength rare-earth aluminosilicate glass and a preparation method thereof. The provided high-strength rare-earth aluminosilicate glass is made from a batch material comprising the following raw materials in parts by weight: 48-58 parts of SiO2, 15-24 parts of Al2O3, 9-21 parts of RE2O3, 1-4 parts of MgO, 5-10 parts of Na2O, 1-6 parts of Li2O, and 0.5-1.5 parts of K2O. The provided preparation method includes uniformly mixing the batch material, melting to obtain a glass melt, subjecting the melted glass melt to forming and annealing treatments, and then performing chemical strengthening. The high-strength rare-earth aluminosilicate glass provided by the present invention has relatively high strength and Vickers hardness, and simultaneously has properties such as high wear resistance, transparency, scratch resistance, and impact resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of glass, and particularly relates to a high-strength rare earth aluminosilicate glass and a preparation method thereof. Background Art

[0002] With the continuous progress of intelligent displays, especially smartphones, electronic glass has witnessed rapid development. Due to the advantages of beautiful appearance, mature technology, excellent performance, and low cost, the electronic glass used as the cover glass of smartphones has gradually replaced the original metal shell, and currently, the application of smartphone cover glass has become an important part of the application of electronic glass. Cover glass, also known as window protection glass or touch screen protection glass, is a transparent lens added outside the display screen to protect the touch module and display module. Cover glass is mainly divided into soda-lime silicate glass, soda-aluminum silicate glass, and lithium-aluminum silicate glass (both soda-aluminum and lithium-aluminum belong to alkali-aluminum silicate glass) according to chemical components.

[0003] Ordinary soda-lime glass can no longer meet its required performance, and it is difficult to improve its performance even after chemical strengthening. As a protective cover glass, it needs to meet performance requirements such as thickness and transparency when in contact with the outside world, and also needs to meet performance requirements such as high strength, high hardness, compression resistance, scratch resistance, and impact resistance. Currently, the most widely used is high-aluminum glass, which has higher strength than ordinary soda-lime glass and stronger ion exchange ability.

[0004] High-aluminum glass has already been the preferred glass cover for electronic product touch screens, and the alumina content in the components of high-aluminum glass in the current market has been in a relatively high and rising trend. The increase in alumina content can effectively improve the scratch resistance of the glass and continuously increase the height of the mobile phone when it drops as a whole. Patent document CN116903248A provides a composition for preparing high-aluminum glass, in which the alumina content reaches 14-23wt%, having excellent mechanical properties and making the surface compressive stress value reach more than 980MPa after ion exchange. However, the Young's modulus of its high-aluminum glass is ≤75GPa, and the stress layer depth after ion exchange is 30-42μm. It is far lower than the performance requirements of the glass in the present invention and cannot meet the market demand. Patent document CN113149428A discloses a preparation method of high-aluminum glass and high-aluminum tempered glass, making the alumina content of the glass reach 25-31wt%, having higher strength and surface hardness, and the Vickers hardness after ion strengthening reaches 680Kgf / mm 2As mentioned above, a high content of alumina can make the glass body have better chemical stability. After ion exchange, the tempered glass has a relatively high surface compressive stress value (500 - 1000 MPa) and a relatively deep compressive stress layer depth (≥100 μm). However, due to the introduction of excessive alumina, the viscosity of the glass melt is high and the surface tension is large, which increases the difficulty of melting, clarification, and homogenization. During the production process, defects such as many bubbles, glass ribs, line marks, and stripes are likely to occur, and it is very difficult to produce using general production techniques (float process), which greatly increases the cost of aluminosilicate glass. In patent document CN111995243A, by adding 0 - 15 mol% of lithium oxide and 6 - 20 mol% of sodium oxide, and in patent document CN112010552A, by adding 9.5 - 20 wt% of sodium oxide and 3 - 8 wt% of lithium oxide, etc., high contents of sodium oxide and lithium oxide are added to make up for the production difficulty brought by high-content alumina, and at the same time, good conditions for secondary ion exchange are created. The depth of its ion exchange layer can reach more than 100 μm and a surface compressive stress of more than 800 MPa can be obtained, making its impact resistance better. However, due to the booming development of lithium batteries, the price of lithium has been staying high, which is much more expensive than the prices of other materials. This directly leads to a very high production cost of cover glass. Reducing the dosage of lithium oxide to reduce the production cost under the condition of ensuring ion exchange, and at the same time still being able to reduce the melting temperature and viscosity on the basis of high-content alumina to reduce the process difficulty are the problems that need to be solved currently. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the above-mentioned existing technologies, and provide a high-strength rare earth aluminosilicate glass and its preparation method. On the basis of maintaining a relatively high alumina content, a certain amount of rare earth elements are added, and the rare earth elements are used as one of the main components of the glass. Compared with alkali metal and alkaline earth metal oxides, rare earth oxides have higher ionic field strength and dissociation energy, which will make the network structure of the glass become more compact, and can greatly improve the performance of the glass in terms of abrasion resistance, optical properties, and chemical stability. With the continuous mining and separation of rare earths, light rare earths separated along with praseodymium and neodymium, especially lanthanum and cerium, have had an overstock problem. Using rare earth elements in glass production can not only significantly reduce costs, but also effectively solve the problem of rare earth overstock. At the same time, rare earth elements will also replace part of the aluminum element and lithium element. Without affecting the subsequent chemical strengthening of the glass, it can further reduce the production difficulty and cost of high-aluminum glass, and at the same time can also meet the requirements of high strength, high hardness, compression resistance, scratch resistance, and impact resistance required by the performance of cover glass in the market. And the strengthened high-aluminum glass can reach a relatively high compressive stress and surface compressive layer depth.

[0006] The present invention is realized through the following technical solutions.

[0007] In a first aspect, the present invention provides a high-strength rare earth aluminosilicate glass, which is made from a batch material comprising the following raw materials in parts by weight: 48 - 58 parts of SiO2, 15 - 24 parts of Al2O3, 9 - 21 parts of RE2O3, 1 - 4 parts of MgO, 5 - 10 parts of Na2O, 1 - 6 parts of Li2O, 0.5 - 1.5 parts of K2O.

[0008] In some embodiments, the batch material further comprises 0.2 - 0.5 parts of Sb2O3.

[0009] In some embodiments, the RE2O3 comprises La2O3, CeO2 and Y2O3; preferably, the mass ratio of (La2O3 + CeO2 + Y2O3) to the total composition ≥ 9%, and designing the content of (La2O3 + CeO2 + Y2O3) to be ≥ 9% can improve properties such as the hardness, Young's modulus and fracture toughness of the glass; more preferably, the mass ratio of CeO2 / La2O3 is 0.0 - 0.8, and the mass ratio of Y2O3 / La2O3 is 0.0 - 1.0. Controlling the content ratio of the above components can further improve properties such as the hardness, Young's modulus and fracture toughness of the glass.

[0010] In some embodiments, the mass ratio of MgO / Al2O3 is 0.04 - 0.3. Designing the mass ratio of MgO / Al2O3 within the above range can reduce the glass melting temperature and improve the glass stability.

[0011] In some embodiments, the mass ratio of RE2O3 / Al2O3 is 0.3 - 1.4, and the mass ratio of RE2O3 / (Al2O3 + Li2O) is 0.3 - 1.35. Controlling the content relationship of the above components can effectively reduce the glass melting temperature and high-temperature viscosity.

[0012] In some embodiments, the mass ratio of (Na2O + Li2O + K2O) to the total composition ≤ 20%, which can further enhance the ion exchange depth.

[0013] SiO2, as a network former, is an essential component of the glass. The silicon-oxygen tetrahedron [SiO4] forms the main glass network structure as the basic structural unit, improving the chemical stability, mechanical properties and thermal stability of the glass, and at the same time reducing its crystallization tendency. However, too high a content of SiO2 will increase the glass melting temperature, increase the melting difficulty and production cost, and also cause defects such as a large number of small bubbles in the glass. Therefore, the present invention limits the mass ratio of SiO2 to 48 - 58%.

[0014] Al2O3, as a network intermediate, is a secondary structural component of the glass skeleton. Al2O3 is one of the essential components and belongs to the network intermediate composition. In the glass composition with a high alkali content, alkaline ions pair with Al 3+The ions balance the charge, causing most of the alumina to tend to form aluminum-oxygen tetrahedrons, which constitute the main glass network structure, thereby improving the stability and mechanical properties of the glass. On the other hand, the volume of the aluminum-oxygen tetrahedrons formed by Al2O3 in the glass is larger than that of the silicon-oxygen tetrahedrons, which will cause the glass volume to expand, thereby reducing the density of the glass, providing an exchange channel for the glass during the ion exchange process, increasing the depth of the glass compressive stress layer. At the same time, the glass with a high Al2O3 concentration has a high strain point temperature, so that the glass can maintain a high compressive layer stress after ion exchange. Therefore, the mass fraction of Al2O3 in the glass of the present invention is at least ≥15%. However, Al2O3 belongs to extremely refractory oxides, which can rapidly increase the high-temperature viscosity of the glass, making it difficult to clarify and homogenize the glass, and the concentration of bubble defects in the glass increases significantly. Therefore, the mass fraction of Al2O3 in the glass does not exceed 24%.

[0015] As a rare earth oxide, La2O3 can form bonding La-O-Si and La-O-Al with silicon-oxygen tetrahedrons and aluminum-oxygen hexahedrons in the glass, forming more stable structural units, thereby increasing its structural stability and glass density. The addition of La2O3 can reduce the glass viscosity and melting temperature, promote the melting and preparation process of the glass, and play the role of a flux. As a glass network modifier, it can significantly improve the mechanical strength and stiffness of aluminosilicate glass, and can greatly improve the glass properties in terms of abrasion resistance, optical properties and chemical stability. Similarly, as a rare earth oxide Y2O3, the dissociation energies of La-O bonds and Y-O bonds are 799 and 715 kJ / mol respectively, which are very close to the dissociation energy of Si-O bonds (798 kJ / mol) and will not cause a significant decrease in the intrinsic strength of the glass. Y 3+ As a rare earth ion with a high ionic field strength, filling it into the glass network as a network modifier can also improve the physical and chemical properties of the glass. And CeO2 can also improve the mechanical properties and optical properties of the glass. Therefore, the mass fraction of La2O3 + CeO2 + Y2O3 is at least greater than 9%. As one of the main components of the glass, if the rare earth oxide is higher than a certain content, it will exceed the glass formation region and serious devitrification will occur. Therefore, in the present invention, the mass fraction of La2O3 + CeO2 + Y2O3 is limited not to exceed 21%.

[0016] MgO belongs to alkaline earth metal oxides, which are components outside the glass network, which play a destructive role in the glass network structure, reduce the glass melting temperature, play a fluxing role and can also improve the stability of the glass. It is beneficial to clarification and prevent the glass from crystallizing. However, if it is higher than a certain content, it may prevent the ion exchange rate during the chemical strengthening process. Therefore, in the present invention, the mass fraction of MgO is limited to 1-4%.

[0017] As one of the essential components for ion exchange, when there is sufficient Na2O in the glass, it can provide a large amount of Na + which can undergo ion exchange with K in the molten salt + to form a high compressive stress on the glass surface. At the same time, Na2O can provide a large amount of free oxygen, thereby breaking the Si - O bond in the silica network structure, reducing the viscosity and melting temperature of the glass. Therefore, the mass proportion of Na2O should be not less than 5%. When the content of Na2O is too high, it will increase the thermal expansion coefficient of the glass and reduce the chemical stability and mechanical properties of the glass. Therefore, the mass proportion of Na2O in the glass is not more than 10wt%.

[0018] Li2O is one of the main components for ion exchange. Due to its polarization characteristics, it can effectively reduce the glass viscosity and melting temperature, and is an excellent flux. Li + has a very small ionic radius, so it can fill the voids inside the glass body and balance the free oxygen. In the mixed molten salt of NaNO3 and KNO3 used in the present invention, Li in the glass + undergoes ion exchange with Na in the molten salt + to quickly obtain a high compressive stress layer depth, enabling the glass to have good compressive and impact resistance and other properties. Therefore, the mass proportion of Li2O is not less than 1wt%. If the concentration of Li2O is insufficient, the exchange amount of Li + and Na + in the glass will be insufficient, and it will be difficult to obtain the required stress layer depth. If the mass proportion of Li2O is too high, it will greatly increase the production cost of the glass, and at the same time, the thermal expansion coefficient of the glass will also increase significantly with the increase of Li2O, which is not conducive to the stability and durability of the glass. Therefore, the mass proportion of Li2O is not more than 6%.

[0019] K2O, Na2O and Li2O all belong to alkali metal oxides. They can increase the ion exchange rate and deepen the compressive stress layer, and can also play a role in breaking the network, reducing the viscosity and melting temperature of the glass. The simultaneous presence of a small amount of K2O and Na2O can form a mixed alkali effect, which can optimize a series of properties of the glass. K + has a larger radius compared to Na + and Li + and a smaller field strength, so its ability to combine with oxygen is weak. Excessive K2O will hinder the ion exchange of Li + and Na + and reduce the surface stress value. Therefore, the mass proportion of K2O is preferably in the range of 0.5 - 1.5wt%.

[0020] In a second aspect, the present invention provides a method for preparing a high - strength rare - earth aluminosilicate glass, which includes the following steps:

[0021] (1) Mix the batch materials for preparing high-strength rare earth aluminosilicate glass evenly, keep them at 1500 - 1630 °C for 3 - 5 h for melting to obtain glass melt;

[0022] (2) Shape the melted glass melt, and after shaping, keep it at the annealing temperature of 600 - 700 °C for 2 - 5 h for annealing treatment; and

[0023] (3) Cool it to the temperature near the strain point at a rate of less than 1 °C / min, and then naturally cool it to room temperature to obtain the base glass.

[0024] In some embodiments, after the base glass is immersed in a 5% HCl solution at 95 °C for 24 h, the weight loss of the base glass is not higher than 4 mg / cm 2 .

[0025] In some embodiments, after the base glass is immersed in a 5% NaOH solution at 95 °C for 6 h, the weight loss of the base glass is not higher than 2.5 mg / cm 2 .

[0026] In some embodiments, the light transmittance of the base glass in the visible light band is greater than 90%.

[0027] In some embodiments, the Young's modulus of the base glass is ≥ 80 GPa, preferably ≥ 90 GPa.

[0028] In some embodiments, the Vickers hardness of the base glass is ≥ 630 Kgf / mm 2 , preferably ≥ 660 Kgf / mm 2 .

[0029] In some embodiments, the fracture toughness of the base glass is ≥ 1.40 MPa·m 1 / 2 , preferably ≥ 1.5 MPa·m 1 / 2 .

[0030] In some embodiments, the preparation method further includes chemically strengthening the base glass, and the operations of the chemical strengthening include the following steps:

[0031] (4) First ion exchange: Put the base glass into the first molten salt for the first ion exchange. The composition of the first molten salt includes KNO3 and NaNO3, and the mass ratio of NaNO3 / KNO3 in the first molten salt is 2.0 - 4.0:1; the temperature of the first ion exchange is 350 - 450 °C, and the time is 3 - 8 h; and

[0032] (5) Secondary ion exchange: The glass after the first ion exchange is put into a second molten salt for secondary ion exchange. The second molten salt is 100 wt% KNO3. The temperature of the secondary ion exchange is 400 - 550 °C, and the time is 1 - 3 h. The strengthened glass is obtained.

[0033] In some embodiments, the strengthened glass has a surface compressive stress value of ≥ 800 MPa, preferably ≥ 900 MPa, and more preferably ≥ 1000 MPa, and a depth of the compressive stress layer of more than 80 μm.

[0034] In some embodiments, the Vickers hardness of the strengthened glass is higher than 680 kgf / mm 2 , preferably higher than 700 kgf / mm 2 , and the fracture toughness is ≥ 1.4 MPa·m 1 / 2 , preferably ≥ 1.6 MPa·m 1 / 2 .

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. By introducing rare earth oxide RE2O3 in the present invention, it becomes one of the main components in aluminosilicate glass second only to SiO2 and Al2O3. The rare earth aluminosilicate glass replaces part of the Li element in the original glass with rare earth elements La, Y, and Ce. Without affecting the subsequent ion exchange, it can solve the problem that the content of lithium oxide in the above patent is too high, resulting in too high production cost of the glass, can greatly reduce the raw material cost of high-aluminum glass, and at the same time can solve the backlog problem caused by the separation of rare earth elements.

[0037] 2. The rare earth aluminosilicate glass of the present invention can promote the melting and preparation process of the glass by introducing rare earth oxide and adding rare earth elements La, Y, and Ce, playing the role of a flux, and can solve the problems such as high viscosity of the glass melt, large surface tension, and high glass melting temperature caused by too high alumina content in the above patent. It can reduce the technical requirements for melting glass, greatly reduce the high-temperature energy consumption, and at the same time can also reduce the loss of molds and equipment.

[0038] 3. On the basis of overcoming the above-mentioned deficiencies of the prior art, the present invention can expand the application fields of rare earth elements lanthanum, cerium, and yttrium in glass. Compared with alkali metal and alkaline earth metal oxides, rare earth oxides have a larger ionic field strength and a higher dissociation energy. The addition of La, Ce, and Y elements makes the glass have better mechanical strength and stiffness, and is improved in terms of abrasion resistance, optical properties, and chemical stability. Its Young's modulus, shear modulus, and Vickers hardness are significantly greater than those of the traditional cover glass sodium-calcium-silicate system and the currently popular alkali-aluminum-silicate glass system, and the rare earth aluminosilicate glass also exhibits good thermal stability. Through the overall implementation of the technology, not only the requirements of high hardness, high elasticity, and high fracture toughness for the cover glass used in touch screen protection are met in terms of performance, but more importantly, the high-content and high-value application of high-abundance rare earth elements in the cover glass used in touch screen protection can be realized, promoting the balanced utilization of rare earth resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a micrograph of a Vickers indentation under a 1.96N load before ion strengthening of the base glass in Example 1 of the present invention;

[0040] Figure 2 It is a micrograph of a Vickers indentation under a 1.96N load after ion strengthening of the base glass in Example 1 of the present invention;

[0041] Figure 3 It is the transmittance curve of the glass in Examples 1-4 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] The present invention will be described in detail below with reference to specific comparative examples, examples, and drawings. These examples and some of the comparative examples are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following examples.

[0043] Unless otherwise specified, the equipment used in the following examples is all conventional equipment in the art; unless otherwise specified, the reagents used are all commercially available products or prepared by conventional methods in the art. Those not described in detail in the following examples can be achieved by conventional experimental means in the art.

[0044] Example:

[0045] 1. Preparation of rare earth aluminosilicate base glass

[0046] Examples 1-6 and Comparative Examples 1-2, 5-6 of the present invention were prepared by the following method: The basic glass raw materials (batch) were mixed evenly according to the proportions in Table 1, and then the mixture was transferred to a platinum crucible. The platinum crucible was placed in a silicon molybdenum rod high-temperature furnace and gradually heated to 1500-1630 °C (for example, 1550 °C), held for 3-5 h (for example, 4 h), and the bubbles were discharged and the glass was homogenized by stirring. After melting, the molten liquid (i.e., glass liquid) was formed, and then annealed at an annealing temperature of 600-700 °C (for example, 650 °C) for 2-5 h (for example, 3.5 h), and then cooled to a temperature near the strain point at a rate of less than 1 °C / min, and then naturally cooled to room temperature to obtain the basic glass. Comparative Example 3 was prepared according to Example 1 in Patent Document CN112010552A, and Comparative Example 4 was prepared according to Example 3 in Patent Document CN116903248A.

[0047] 2. Preparation of rare earth aluminosilicate chemically strengthened glass:

[0048] The basic glasses (with a thickness of 0.7 mm) prepared in Examples 1-6 and Comparative Examples 1-2, 5-6 were put into the first molten salt (NaNO3 / KNO3 mass ratio of 3:1) for the first ion exchange at a temperature of 450 °C for 4 h, and then put into the second molten salt (100 wt% KN03) for the second ion exchange at an ion exchange temperature of 420 °C for 2 h. Table 2 shows the performance test results of the corresponding basic glasses in Examples and Comparative Examples in Table 1 before and after ion exchange, including acid and alkali resistance, Young's modulus, Vickers hardness, fracture toughness, surface compressive stress, and stress layer depth.

[0049] Explanation of the test methods in Table 2:

[0050] 1. 5% HCl weight loss (mg / cm 2 ): The cleaned and dried glass sample was immersed in a 5% HCl solution at a temperature of 95 °C for 24 hours; a ten-thousandth precision balance was used to measure the change in the glass mass before and after immersion, and the weight loss ratio of the glass in the 5% HCl solution was calculated by measuring the glass surface area.

[0051] 2. 5% NaOH weight loss (mg / cm 2 ): The cleaned and dried glass sample was immersed in a 5% NaOH solution at a temperature of 95 °C for 6 hours; a ten-thousandth precision balance was used to measure the change in the glass mass before and after immersion, and the weight loss ratio of the glass in the 5% NaOH solution was calculated by measuring the glass surface area.

[0052] Table 1: Glass compositions of Examples 1-6 and Comparative Examples 1-6

[0053]

[0054] Table 2: Performance tests of the glasses of Examples 1-6 and Comparative Examples 1-6 before and after ion exchange

[0055]

[0056] Figure 1 and Figure 2 are respectively the Vickers indentation morphology diagrams of the rare earth aluminosilicate glass of Example 1 of the present invention before and after ion exchange. The Vickers hardness of the glass of Example 1 before ion exchange was 663 Kgf / mm 2 and the Vickers hardness after ion exchange was 702 Kgf / mm 2 . It shows that ion exchange improves the mechanical properties of the glass.

[0057] Figure 3 are the transmittance curves of the glasses of Examples 1-4. The transmittance of the rare earth aluminosilicate glass of the present invention in the visible light band (380 nm - 780 nm) all reaches more than 90%.

[0058] It can be seen from the results in Table 2 that the Young's moduli of the base glasses of Examples 1-6 all exceed 90 GPa, and the weight loss after being immersed in a 5% HCl solution at 95 °C for 24 h is between 3.2 - 3.9 mg / cm 2 . After being immersed in a 5% NaOH solution at 95 °C for 6 h, the weight loss of the glass is between 1.9 - 2.3 mg / cm 2 . They have excellent mechanical properties and chemical stability. After ion exchange, the Vickers hardness and fracture toughness of the rare earth aluminosilicate glasses of Examples 1-6 are both improved. The Vickers hardness after improvement of Examples 1-6 all reaches above 700 Kgf / mm 2 and the fracture toughness reaches 1.62 - 1.82 MPa·m 1 / 2 . The glasses of Examples 1-6 can achieve a surface compressive stress CS ≥ 1000 Mpa and a depth of the stress layer DOL > 80 μm, which is beneficial to improving the drop resistance and can better meet the application requirements of touch screen protection glass.

[0059] The Young's modulus, Vickers hardness, fracture toughness and chemical stability of the glasses of Comparative Example 1 and Comparative Example 2 are much lower than those of Examples 1-6. It can be seen from the glass composition table in Table 1 that the content of rare earth oxides La2O3 + CeO2 + Y2O3 in the glass compositions of Comparative Example 1 and Comparative Example 2 is much lower than 9 wt%. Without sufficient contents of rare earth elements La, Ce, and Y, the elastic modulus is lower than 70 GPa, and the Vickers hardness also fails to exceed 640 Kgf / mm after ion strengthening 2Meanwhile, the surface compressive stress (<800 Mpa) and the stress layer depth (<60 μm) of the glass do not meet the corresponding performance requirements, and the glass has poor drop resistance.

[0060] Comparative Example 3 is Example 1 in Patent Document CN112010552A. It can be seen from the glass composition in Table 1 that the lithium oxide content in the glass composition of Comparative Example 3 is 7.45 wt% and the sodium oxide content is 11.82 wt%, which are much higher than those of the glasses in Examples 1-6 and exceed the component content ranges of lithium oxide and sodium oxide in the present invention. It can be seen from the results in Table 2 that its Young's modulus is 76 GPa, which is much lower than that of the glasses in Examples 1-6. Due to the high content of lithium oxide and sodium oxide in the composition, the stress layer depth DOL after ion exchange reaches 117 μm. However, the Vickers hardness is only 642 Kgf / mm 2 The high content of lithium oxide in the glass composition of Comparative Example 3 greatly increases the production cost, and its performance is lower than that of the glasses in Examples 1-6 of the present invention except for the stress layer depth.

[0061] Comparative Example 4 is Example 3 in Patent Document CN116903248A. It can be seen from the glass composition in Table 1 that the alumina content in the glass composition of Comparative Example 4 is 23 wt%, the sodium oxide content is 22 wt%, and the lithium oxide content is 0.3 wt%. A high content of sodium oxide is added to obtain a fluxing effect. It can be seen from the results in Table 2 that the Young's modulus of the glass in Comparative Example 4 is 73 GPa, which is lower than that of the glasses in Examples 1-6. Due to the extremely high sodium oxide content, the surface compressive stress after ion exchange can reach 1150 Mpa, but the extremely low lithium oxide content makes its stress layer depth only 42 μm. Although the glass composition of Comparative Example 4 solves the cost problem caused by lithium oxide and the high-temperature melting problem of high-aluminum glass, its mechanical properties are lower than those of Examples 1-6 in the present invention, and the Vickers hardness after ion exchange is only 638 Kgf / mm 2 Moreover, the relatively low stress layer depth results in poor drop resistance.

[0062] The content of rare earth oxides La2O3 + CeO2 + Y2O3 in the glass composition of Comparative Example 5 exceeds 21 wt%. Its composition is no longer in the corresponding glass-forming region in the phase diagram, and it is found that the glass of Comparative Example 5 has a large area of white devitrified regions and cannot meet the requirement of transparency for touch screen protection glass. The content of rare earth oxides La2O3 + CeO2 + Y2O3 in the glass composition of Comparative Example 6 is lower than 9 wt%, and the content of CeO2 is too high, making the glass color present brownish black. Due to the relatively low rare earth content, the Young's modulus, Vickers hardness, fracture toughness, and chemical stability of the glass are much lower than those of the glasses in Examples 1-6.

[0063] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-strength rare earth aluminosilicate glass, characterized in that, The high-strength rare earth aluminosilicate glass is made from a batch of raw materials including the following parts by weight: 48 - 58 parts of SiO2, 15 - 24 parts of Al2O3, 9 - 21 parts of RE2O3, 1 - 4 parts of MgO, 5 - 10 parts of Na2O, 1 - 6 parts of Li2O, 0.5 - 1.5 parts of K2O; The RE2O3 includes La2O3, CeO2 and Y2O3; the mass ratio of (La2O3 + CeO2 + Y2O3) in the total composition is ≥9% and ≤21%; the mass ratio of CeO2 / La2O3 is 0.0 - 0.8, and the mass ratio of Y2O3 / La2O3 is 0.0 - 1.0; The mass ratio of MgO / Al2O3 is 0.04 - 0.3; The mass ratio of RE2O3 / Al2O3 is 0.3 - 1.4; The mass ratio of RE2O3 / (Al2O3 + Li2O) is 0.3 - 1.35; The high-strength rare earth aluminosilicate glass has a surface compressive stress value of ≥1000 MPa and a compressive stress layer depth of more than 80 μm; and The Vickers hardness of the high-strength rare-earth aluminosilicate glass is higher than 700 kgf / mm 2 , and the fracture toughness ≥ 1.6 MPa·m 1 / 2 .

2. The high-strength rare earth aluminosilicate glass according to claim 1, wherein The batch also includes 0.2 - 0.5 parts of Sb2O3.

3. The high-strength rare earth aluminosilicate glass according to claim 1 or 2, characterized in that, (Na2O + Li2O + K2O) accounts for a mass ratio of ≤20% in the total composition.

4. The preparation method of the high-strength rare earth aluminosilicate glass according to any one of claims 1-3, characterized in that, The preparation method includes the following steps: (1) Mix the batch for preparing the high-strength rare earth aluminosilicate glass evenly, keep it warm at 1500 - 1630 °C for 3 - 5 h, and carry out melting to obtain glass liquid; (2) Shape the melted glass liquid, and after shaping, keep it warm at the annealing temperature of 600 - 700 °C for 2 - 5 h for annealing treatment; (3) Cool it to a temperature near the strain point at a rate of less than 1 °C / min, and then cool it naturally to room temperature to obtain the base glass; and Carry out chemical strengthening on the base glass, and the operations of the chemical strengthening include the following steps: (4) First ion exchange: Put the base glass into the first molten salt for the first ion exchange. The composition of the first molten salt includes KNO3 and NaNO3, and the mass ratio of NaNO3 / KNO3 in the first molten salt is 2.0 - 4.0:1; the temperature of the first ion exchange is 350 - 450 °C, and the time is 3 - 8 h; and (5) Second ion exchange: Put the glass after the first ion exchange into the second molten salt for the second ion exchange. The second molten salt is 100 wt% KNO3; the temperature of the second ion exchange is 400 - 550 °C, and the time is 1 - 3 h; to obtain the high-strength rare earth aluminosilicate glass.

5. The preparation method according to claim 4, characterized in that, After the base glass is immersed in a 5% HCl solution at 95 °C for 24 h, the weight loss of the base glass is not higher than 4 mg / cm 2 ; and / or After the base glass is immersed in a 5% NaOH solution at 95 °C for 6 h, the weight loss of the base glass is not higher than 2.5 mg / cm 2 ; and / or The light transmittance of the base glass in the visible light band is greater than 90%; and / or The Young's modulus of the base glass is ≥80 GPa; and / or The Vickers hardness of the base glass is ≥ 630 Kgf / mm 2 ; and / or The fracture toughness of the base glass ≥ 1.40 MPa·m 1 / 2 .

6. The preparation method according to claim 5, wherein The Young's modulus of the base glass is ≥90 GPa; and / or The Vickers hardness of the base glass is ≥ 660 Kgf / mm 2 ; and / or The fracture toughness of the base glass ≥ 1.5 MPa·m 1 / 2 .

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