High-lithium-content glass-ceramic, chemically strengthened glass-ceramic and use thereof

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

High-lithium-content glass-ceramics, chemically strengthened glass-ceramics, and applications thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number 202410156329.0 filed with the Patent Office of China on February 2, 2024, entitled “A high lithium content microcrystalline glass, chemically strengthened microcrystalline glass and its application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application belongs to the field of microcrystalline glass technology, and specifically relates to a high-lithium content microcrystalline glass, chemically strengthened microcrystalline glass and their applications. Background Art

[0004] Glass-ceramics, a solid material containing both microcrystalline and glass phases, possesses significant strength advantages over conventional glass due to its numerous nanoscale crystals that inhibit the growth of microcracks. Currently, glass-ceramics is increasingly being used in portable electronic devices as cover glass, such as display screen protectors or rear covers.

[0005] The lithium disilicate (Li2Si2O5) crystalline phase is an orthorhombic crystal based on an array of [Si2O5] tetrahedrons, and the crystals are flat or plate-like in shape. Inside the glass-ceramics, the lithium disilicate crystals are randomly oriented interlocking microstructures, forcing the crack path to distort as it passes through the crystal, thereby preventing the crack from expanding and improving the strength and fracture toughness of the glass-ceramics. At the same time, the refractive index of lithium disilicate crystals is close to that of the glass matrix (e.g., the base glass used to prepare glass-ceramics), making it an ideal crystalline phase for preparing highly transparent glass-ceramics. This shows that glass-ceramics with a main lithium disilicate crystalline phase have great application potential in the cover glass market for electronic products or electronic devices. Summary of the Invention

[0006] As the cover glass of electronic devices, especially the cover glass of portable electronic devices (such as mobile phones, watches, PADs, etc.), the thickness is generally less than 2 mm. For example, the thickness of the cover glass of the electronic device can be about 0.1 mm-2.0 mm. Therefore, in order to meet the high performance requirements such as anti-fall, pressure resistance, scratch resistance, and wear resistance, it is usually necessary to chemically strengthen the cover glass of the electronic device to further improve its mechanical strength performance. The so-called "chemical strengthening" here refers to placing the glass in a molten salt bath, using the alkali metal ions with large ionic radius in the molten salt to exchange ions with the alkali metal ions with small ionic radius in the glass, thereby generating compressive stress on the glass surface. In order to improve the efficiency of the chemical strengthening treatment and reduce production costs, the art generally considers using a high-temperature molten salt bath to chemically strengthen the glass.

[0007] However, glass-ceramics with a high lithium content and containing a primary lithium disilicate crystalline phase are susceptible to surface cracking and / or peeling during chemical strengthening treatment in a high-temperature molten salt bath exceeding 480°C. "Surface cracking" here refers primarily to the appearance of numerous irregular cracks on the surface of the glass-ceramics after chemical strengthening, while "peeling" refers primarily to the detachment of the outermost layer of the glass-ceramics after chemical strengthening, with the thickness of the detached glass layer ranging from a few microns to tens of microns. This surface cracking and / or peeling can significantly reduce the drop resistance and mechanical strength of the glass-ceramics, and may even render the surface of the chemically strengthened glass-ceramics inoperable, rendering it unusable.

[0008] The purpose of this application is to overcome the defects of "surface cracking" and / or "peeling" that exist in glass-ceramics with a high lithium content and containing a main crystalline phase of lithium disilicate when chemically strengthened in a high-temperature salt bath (e.g., a salt bath temperature of 480°C or above), and to provide a high-lithium-content glass-ceramics, a chemically strengthened glass-ceramics, and their applications that are suitable for high-temperature chemical strengthening and whose main crystalline phase is lithium disilicate. After high-temperature chemical strengthening, the high-lithium-content glass-ceramics not only overcomes the problems of "surface cracking" and / or "peeling", but also can produce chemically strengthened glass-ceramics with a high stress level after high-temperature chemical strengthening. By adopting the high-lithium-content glass-ceramics for high-temperature chemical strengthening treatment to obtain chemically strengthened glass-ceramics with high stress level and high mechanical strength properties, the efficiency of preparing high-strength chemically strengthened glass-ceramics can be greatly improved.

[0009] In order to achieve the above objectives, this application provides the following technical solutions:

[0010] The present application provides a high-lithium-content glass-ceramic, wherein the high-lithium-content glass-ceramic comprises a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the high-lithium-content glass-ceramic;

[0011] Measured in mole percentage of oxides, the composition of high lithium content glass-ceramics includes:

[0012] SiO2: 41.00mol%-69.50mol%, Al2O3: 0.00mol%-2.00mol%, P2O5: 1.50mol%-3.00mol%, ZrO2: 2.00mol%-6.00mol%, MgO :0.00mol%-2.00mol%, ZnO: 0.00mol%-2.00mol%, Na2O: 0.00mol%-3.00mol%, K2O: 0.00mol%-1.00mol%, Li2O: 27.00mo 1%-32.00mol%, CaO: 0.00mol%-5.00mol%, B2O3: 0.00mol%-1.00mol%, SrO: 0.00mol%-2.00mol%; the composition of the high lithium content microcrystalline glass satisfies the following requirements: 0.20≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.41, optionally, 0.21≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.39, in terms of the content of each oxide expressed in molar percentage in the composition of the high lithium content microcrystalline glass. By optimizing the glass formula so that the components satisfy a specific content relationship and interact with each other, on the one hand, it is beneficial to ensure the precipitation of the desired content of lithium disilicate crystal phase and limit the precipitation of other crystal phases (such as lithium feldspar crystal phase), thereby helping to ensure the acquisition of microcrystalline glass with high intrinsic strength and excellent optical properties and with lithium disilicate as the main crystal phase. On the other hand, it is beneficial to ensure that the microcrystalline glass meets the specific composition and structure, thereby ensuring that it can achieve high-temperature chemical strengthening and ensuring that it will not have "surface cracking" and / or surface "peeling" problems during the high-temperature chemical strengthening process, thereby helping to improve its chemical strengthening efficiency and can ensure that the chemically strengthened microcrystalline glass prepared thereby meets high stress levels (such as high CS_50, |CT_AV|, DOL_0, etc.) and high mechanical strength properties.

[0013] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics, expressed as a molar percentage of each oxide in the high-lithium-content glass-ceramics, further satisfies the following: 0.25 ≤ (2.2 × ZrO2 + 0.35 × CaO + Na2O) / Li2O ≤ 0.45; alternatively, 0.27 ≤ (2.2 × ZrO2 + 0.35 × CaO + Na2O) / Li2O ≤ 0.43. By ensuring that the composition of the glass-ceramics satisfies this relationship, the high-lithium-content glass-ceramics can be ensured to have high intrinsic strength and excellent optical properties while avoiding "surface cracking" and / or "peeling" during strengthening of the glass-ceramics in a high-temperature molten salt bath.

[0014] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics satisfies the following requirements, based on the content of each oxide in the high-lithium-content glass-ceramics expressed as a molar percentage:

[0015] 0≤(CaO+MgO+ZnO+Na2O+K2O) / (ZrO2+Li2O)≤0.15; and / or,

[0016] 0.90≤SiO2+Li2O≤0.95; and / or,

[0017] 2.00≤SiO2 / Li2O≤2.30; and / or,

[0018] 0≤(CaO+SrO) / ZrO2≤1.50; and / or,

[0019] 0≤Al2O3 / (SiO2+Al2O3)≤0.03. By ensuring that the composition satisfies at least one of the above-mentioned relationships, it is advantageous to further improve the structure of the glass, thereby facilitating the production of high-lithium-content glass-ceramics that meet specific structural requirements and have excellent properties (especially optical properties, strength properties, etc.). It is also advantageous to ensure the chemical strengthening effect of the high-lithium-content glass-ceramics, ensuring that the high-lithium-content glass-ceramics can be prepared through chemical strengthening to produce chemically strengthened glass-ceramics with high stress levels, excellent mechanical strength properties, and excellent damage resistance.

[0020] It should be pointed out that in the above formulas of the present application, the content percentage is substituted into each formula in molar percentage, that is, the molar unit does not participate in the calculation of the formula. For example, if the molar percentage content of Al2O3 is 2%, 2% is substituted into the formula for calculation.

[0021] In some embodiments of the present application, in terms of molar percentage of oxides, in the high lithium content glass-ceramics:

[0022] The content of SiO2 is 60.00mol%-65.00mol%, optionally, the content of SiO2 is 61.00mol%-63.50mol%; and / or, the content of Li2O is 27.50mol%-31.00mol%, optionally, the content of Li2O is 28.00mol%-30.50mol%; and / or, the content of ZrO2 is 3.00mol%-6.00mol%, optionally, the content of ZrO2 is 3.50mol%-6.00mol%; and / or, the content of P2O5 is 1.50mol%-2.50mol%, optionally, the content of P2O5 is 1.60mol%-2.10mol%; and / or, the content of CaO is 0.00mol%-4.00mol%, optionally, the content of CaO is 0.00mol%-2.00mol%. By adjusting the composition of high-lithium-content glass-ceramics, the high-lithium-content glass-ceramics can obtain higher mechanical strength and damage resistance.

[0023] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics further includes, by mole percentage of oxides, the following: Y2O3: 0.00mol%-1.00mol%, La2O3: 0.00mol%-1.00mol%, and Ta2O5: 0.00mol%-1.00mol%. In the present application, the selective addition of appropriate amounts of Y2O3, La2O3, or Ta2O5 helps to increase the density and Young's modulus of the high-lithium-content glass-ceramics, but may also increase the refractive index of the high-lithium-content glass-ceramics, thereby reducing the optical properties of the high-lithium-content glass-ceramics.

[0024] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics satisfies the following requirements, based on the content of each oxide in the high-lithium-content glass-ceramics expressed as a molar percentage:

[0025] 0≤(CaO+MgO+ZnO+Na2O+K2O) / (ZrO2+Li2O)≤0.10; and / or,

[0026] 0.90≤SiO2+Li2O≤0.93; and / or,

[0027] 0≤(CaO+SrO) / ZrO2≤1.00, optionally, 0≤(CaO+SrO) / ZrO2≤0.70. Ensuring that the composition satisfies at least one of the above relationships further improves the structure of the glass, facilitates the production of chemically strengthened glass-ceramics with higher stress levels, and further ensures that the resulting chemically strengthened glass-ceramics possess excellent mechanical strength and damage resistance.

[0028] In some embodiments of the present application, the density of the high lithium content glass-ceramics is ρ≥2.54 g / cm 3 , refractive index ≤1.60. High lithium content glass-ceramics that meet this density and refractive index can ensure high intrinsic strength and excellent optical properties.

[0029] In some embodiments of the present application, when the high-lithium-content glass-ceramics is 0.5 mm thick, the b-value of the high-lithium-content glass-ceramics is ≤ 1.0, and optionally, the b-value is ≤ 0.8. High-lithium-content glass-ceramics that meet this optical b-value can ensure excellent optical performance and display effects, and are suitable for use in display screens with demanding display effects.

[0030] In some embodiments of the present application, the high-lithium-content glass-ceramics is transparent in the visible light range, and / or, when the high-lithium-content glass-ceramics is 0.5 mm thick, for light of 550 nm wavelength, the transmittance of the high-lithium-content glass-ceramics is ≥ 85.00%, and optionally, the transmittance is ≥ 90.00%. High-lithium-content glass-ceramics with a relatively high transmittance can ensure good light transmittance and transparency, making them suitable for use in display screens with demanding visual effects.

[0031] In some embodiments of the present application, the crystallinity of the high-lithium-content glass-ceramics is 30.00 wt%-90.00 wt%, optionally, 50.00 wt%-90.00 wt%. A higher content of microcrystalline phase is beneficial to improving the mechanical strength of the high-lithium-content glass-ceramics.

[0032] In some embodiments of the present application, the high-lithium-content glass-ceramics has an average crystal size of ≤100 nm, optionally ≤50 nm, and further optionally, an average crystal size of 15 nm to 45 nm. A smaller average crystal size helps ensure that the high-lithium-content glass-ceramics has excellent optical properties.

[0033] In some embodiments of the present application, the Young's modulus of the high-lithium-content glass-ceramics is ≥100.00 GPa. Alternatively, the Young's modulus of the high-lithium-content glass-ceramics is ≥110.00 GPa. More preferably, the Young's modulus of the high-lithium-content glass-ceramics is between 114 GPa and 130 GPa. A higher Young's modulus indicates that the high-lithium-content glass-ceramics has higher intrinsic strength, which is beneficial for achieving higher mechanical strength and damage resistance.

[0034] In some embodiments of the present application, the expansion softening point of the high-lithium-content glass-ceramics is between 750° C. and 820° C. A suitable expansion softening point facilitates 3D hot bending of the high-lithium-content glass-ceramics to produce 3D curved glass-ceramics with high strength.

[0035] The present application also provides a chemically strengthened microcrystalline glass, the composition at the center of which is the same as the composition of the aforementioned high-lithium-content microcrystalline glass, the chemically strengthened microcrystalline glass includes a compressive stress layer region extending from the surface of the chemically strengthened microcrystalline glass to the compression depth, and has tensile stress inside the chemically strengthened microcrystalline glass.

[0036] In some embodiments of the present application, the chemically strengthened glass-ceramics includes a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the chemically strengthened glass-ceramics; and the composition at the center of the chemically strengthened glass-ceramics, measured in molar percentage of oxides, includes:

[0037] SiO2: 41.00mol%-69.50mol%, Al2O3: 0.00mol%-2.00mol%, P2O5: 1.50mol%-3.00mol%, ZrO2: 2.00mol%-6.00mol%, MgO: 0.00mol%-2.00mol%, ZnO: 0.00mol%-2.00mol% , Na2O: 0.00mol%-3.00mol%, K2O: 0.00mol%-1.00mol%, Li2O: 27.00mol%-32.00mol%, CaO: 0.00mol%-5.00mol%, B2O3: 0.00mol%-1.00mol%, SrO: 0.00mol%-2.00mol%;

[0038] The composition at the center of the chemically strengthened microcrystalline glass satisfies the following conditions, expressed as the molar percentage of each oxide in the composition at the center of the chemically strengthened microcrystalline glass: 0.20≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.41, optionally, 0.21≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.39.

[0039] In some embodiments of the present application, the chemically strengthened glass-ceramics has a DOL_0 of 0.20t-0.25t, and optionally, a DOL_0 of 0.22t-0.25t, where DOL_0 represents the depth of the compressive stress layer and t represents the thickness of the chemically strengthened glass-ceramics. The DOL_0 of the chemically strengthened glass-ceramics being within the above range indicates that the chemically strengthened glass-ceramics has a high depth of the compressive stress layer, which helps offset the energy that drives crack propagation, thereby ensuring excellent damage resistance, such as excellent drop resistance.

[0040] In some embodiments of the present application, the chemically strengthened glass-ceramics has a |CT_AV| of 80 MPa-200 MPa, where |CT_AV| is the absolute value of the average tensile stress; alternatively, it has a |CT_AV| of 90 MPa-200 MPa; and more alternatively, it has a |CT_AV| of 130 MPa-200 MPa. The chemically strengthened glass-ceramics have a |CT_AV| within the above range, indicating that the chemically strengthened glass-ceramics have a high tensile stress level, reflecting a high surface compressive stress level. A higher surface compressive stress level can offset more residual energy from a drop, squeeze, impact, or collision, thereby ensuring excellent damage resistance.

[0041] In some embodiments of the present application, the chemically strengthened glass-ceramics has a CT_LD of 50,000 MPa / mm-100,000 MPa / mm, where CT_LD is the tensile stress linear density; alternatively, it has a CT_LD of 55,000 MPa / mm-100,000 MPa / mm; more alternatively, it has a CT_LD of 65,000 MPa / mm-100,000 MPa / mm. The CT_LD of the chemically strengthened glass-ceramics being within the above range indicates that the tensile stress stored within the chemically strengthened glass-ceramics is relatively dense, indicating that the chemically strengthened glass-ceramics has a high surface compressive stress level, thereby ensuring that it has excellent damage resistance, such as excellent drop resistance.

[0042] In some embodiments of the present application, the chemically strengthened glass-ceramics has a CS_50 of 150 MPa to 280 MPa, where CS_50 refers to the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened glass-ceramics; alternatively, the CS_50 is 160 MPa to 280 MPa; and more alternatively, the CS_50 is 180 MPa to 280 MPa. The CS_50 of the chemically strengthened glass-ceramics being within the above range indicates that the compressive stress at a depth of 50 μm from the surface of the chemically strengthened glass-ceramics is high, indicating that the chemically strengthened glass-ceramics has a higher surface compressive stress level. A higher surface compressive stress level can offset more residual energy from a drop, squeeze, impact, or collision, thereby ensuring excellent damage resistance, such as excellent drop resistance.

[0043] In some embodiments of the present application, a sandpaper drop test was conducted on 0.5 mm thick chemically strengthened glass-ceramics using 80-grit sandpaper. The average sandpaper drop resistance height of the chemically strengthened glass-ceramics was ≥1.0 m, optionally ≥1.2 m, and more optionally ≥1.5 m. This indicates that the chemically strengthened glass-ceramics have excellent drop resistance.

[0044] The present application further provides a glass device, wherein the glass device comprises the aforementioned high-lithium-content glass-ceramics or the aforementioned chemically strengthened glass-ceramics.

[0045] The present application further provides an electronic device, wherein the electronic device includes the high-lithium-content microcrystalline glass as described above or includes the chemically strengthened microcrystalline glass as described above. Beneficial effects:

[0046] The present application ensures that the high-lithium-content microcrystalline glass containing lithium disilicate as the main crystalline phase meets specific composition and structure, especially the oxide content and specific oxide content relationship under specific conditions, which not only ensures that it can achieve high-temperature chemical strengthening and ensures that it will not have "surface cracking" and / or surface "peeling" problems during the high-temperature chemical strengthening process, thereby improving its chemical strengthening efficiency, but also ensures that the chemically strengthened microcrystalline glass obtained by it meets high stress levels (such as high CS_50, |CT_AV|, DOL_0, etc.) and high mechanical strength properties. The high-lithium-content microcrystalline glass of the present application can be used to produce chemically strengthened microcrystalline glass with both excellent optical properties and mechanical strength properties, which is conducive to broadening its application scenarios and application fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0048] FIG1 is a physical picture of the chemically strengthened glass-ceramics of Example 1 under strong light.

[0049] FIG2 is a physical picture of the chemically strengthened glass-ceramics of Example 2 under strong light.

[0050] Figure 3 is a morphology image of a cross section of the chemically strengthened microcrystalline glass of Example 1 along the thickness direction under an optical microscope (magnification 200 times); wherein A points to the surface of the chemically strengthened microcrystalline glass of Example 1, and B points to the interior of the chemically strengthened microcrystalline glass of Example 1.

[0051] FIG4 is a physical picture of the chemically strengthened glass-ceramics of Comparative Example 1 under strong light irradiation, showing that the chemically strengthened glass-ceramics exhibits “surface cracking”;

[0052] FIG4A is a morphology image of a cross section along the thickness direction of the chemically strengthened glass-ceramics of Comparative Example 1 under an optical microscope (magnification 200 times);

[0053] FIG4B is a morphology image of a local area of ​​the main surface of the chemically strengthened glass-ceramics of Comparative Example 1 under an optical microscope (50 times magnification);

[0054] In FIG4A and FIG4B , 1 points to the interior of the chemically strengthened glass-ceramics of Comparative Example 1, 2 points to the “crack” region on the main surface of the chemically strengthened glass-ceramics of Comparative Example 1, and 3 points to the air.

[0055] FIG5 is a physical picture of the chemically strengthened micro-ceramic glass of comparative example 12 under natural light, and the chemically strengthened micro-ceramic glass has a surface "peeling" phenomenon.

[0056] Figure 6 is a morphology image of the cross-section of the chemically strengthened microcrystalline glass of Comparative Example 12 along the thickness direction under an optical microscope (magnification 50 times); wherein, 4 points to the interior of the chemically strengthened microcrystalline glass of Comparative Example 12, and 5 points to the surface "peeling" area of ​​the chemically strengthened microcrystalline glass of Comparative Example 12.

[0057] FIG7 is a transmittance curve of the high lithium content glass-ceramics of Example 6 in the 360 ​​nm-740 nm band.

[0058] FIG8 is an XRD pattern of the high lithium content glass-ceramics of Example 6.

[0059] Figure 9 is the XRD spectrum of the microcrystalline glass in Comparative Example 1 before and after chemical strengthening; wherein, curve A is the XRD spectrum of the microcrystalline glass in Comparative Example 1, and curve B is the XRD spectrum of the chemically strengthened microcrystalline glass in Comparative Example 1.

[0060] Figure 10 is the XRD spectrum of the high-lithium-content microcrystalline glass in Example 4 before and after chemical strengthening; wherein, curve C is the XRD spectrum of the high-lithium-content microcrystalline glass in Example 4, and curve D is the XRD spectrum of the chemically strengthened microcrystalline glass in Example 4.

[0061] FIG11 is a test curve of thermal expansion coefficient of high-lithium-content glass-ceramics of Example 8, and the temperature shown in the figure is the expansion softening point temperature of high-lithium-content glass-ceramics. DETAILED DESCRIPTION

[0062] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article. Among them, the terms "optional", "optionally", and "optionally" all mean that they may or may not be included (or may or may not be included).

[0063] Glossary and test methods:

[0064] "Surface cracking" refers to the phenomenon in which chemically strengthened glass (such as chemically strengthened microcrystalline glass) shows obvious cracks on the surface when exposed to strong light.

[0065] Surface "peeling" phenomenon: refers to the phenomenon in which the surface glass of chemically strengthened glass (such as chemically strengthened microcrystalline glass) separates from the glass body.

[0066] Base glass: glass that has not been nucleated, crystallized or strengthened, or also called basic glass.

[0067] Glass-ceramics: also known as glass ceramics, is a type of solid composite material that contains both a glass phase and a crystal phase (also called a microcrystalline phase or a crystalline phase) and is prepared by targeted and controlled crystallization of the base glass.

[0068] Chemically strengthened glass-ceramics refers to the solid composite material obtained by chemically strengthening glass-ceramics. During high-temperature chemical strengthening, alkali metal ions with larger ionic radii (such as potassium or sodium ions) in the molten salt bath replace alkali metal ions with smaller ionic radii (such as sodium or lithium ions) in the glass-ceramics. This creates a volume difference between the exchanged ions and produces compressive stress (also known as compression stress) on the surface of the glass-ceramics.

[0069] Nucleation: Through heat treatment, the nucleating material in the glass grows small crystal nuclei.

[0070] Crystallization: Glass grows a certain type of crystal based on the crystal nucleus through heat treatment.

[0071] Crystalline phase: Crystalline phase is the microscopic structure of crystals. It is a general term for parts composed of a large number of crystalline solid phases, or also called crystals.

[0072] Main crystalline phase: also known as primary crystalline phase, refers to a crystalline phase having a higher weight content than other crystalline phases present in the microcrystalline glass.

[0073] Main surface: refers to the surface with the largest surface area in the glass brick or glass sheet, such as the upper or lower surface of the cover glass.

[0074] Crystallinity: refers to the percentage of the total mass of the crystalline phase or crystals in the microcrystalline glass to the mass of the microcrystalline glass, or also called the total crystalline phase content in the microcrystalline glass.

[0075] Refractive index: The refractive index refers to the ratio of the speed of light in a vacuum to the speed of light in the medium.

[0076] Transmittance: When light of a certain wavelength hits the glass surface, the light will be reflected, absorbed and transmitted. The ratio of the intensity of the transmitted part to the intensity of the incident light is the transmittance.

[0077] SOC: Photoelastic coefficient. Photoelasticity refers to the anisotropic birefringence of transparent materials when subjected to stress. By measuring the photoelastic coefficient and birefringence, the residual stress (in MPa) within the material can be determined.

[0078] CT_LD: refers to the tensile stress linear density, measured in MPa / mm. It should be understood that after the glass-ceramics is placed in a molten salt bath for ion exchange, a compressive stress layer (or also called a compressive stress layer) will be formed on the surface of the glass-ceramics, and a tensile stress layer (or also called a tensile stress layer) will be formed inside the glass-ceramics. Exemplarily, during chemical strengthening, alkali metal ions with a large radius in the molten salt bath are ion-exchanged with alkali metal ions with a small radius in the glass-ceramics, thereby forming a compressive stress layer on the surface of the glass-ceramics and a tensile stress layer inside the glass-ceramics. In this application, CT_LD is calculated by the following formula:

[0079] Where t is the thickness of the chemically strengthened glass-ceramic, in mm; DOL_0 is the depth of the compressive stress layer of the chemically strengthened glass-ceramic, in μm; and |CT_AV| is the absolute value of the average tensile stress of the chemically strengthened glass-ceramic, in MPa. It should be understood that the calculation formula for tensile stress linear density is based on the aforementioned unit requirements, and the units are not involved in the calculation.

[0080] CS_50: refers to the compressive stress value at a depth of 50μm measured from the main surface of the chemically strengthened microcrystalline glass, the unit is MPa.

[0081] |CT_AV|: refers to the absolute value of the average tensile stress, in MPa. Specifically, it refers to the absolute value of the average value of all tensile stresses in the tensile stress layer, obtained by testing with the SLP-2000 stress meter.

[0082] DOL_0: refers to the depth of the compressive stress layer, or the depth of the compressive stress layer. Specifically, it refers to the distance from any major surface of the chemically strengthened microcrystalline glass to the position close to that surface where the compressive stress is zero. It is measured using an SLP-2000 stress meter.

[0083] b value: used to characterize the yellow-blue value of a material. The optical b value in this application refers to the b value of transmitted light. A positive optical b value indicates that the material is blue.

[0084] Crystallization upper limit temperature: Crystallization upper limit temperature refers to the highest temperature at which the substrate glass produces crystallization. Above this temperature, the substrate glass will not precipitate crystals.

[0085] Glass thickness: measured with a micrometer. It should be understood that the degree of ion exchange varies gradually from the surface to the center of the glass through the thickness, and the overall Na-K and / or Li-Na exchange increment (mass) generally does not exceed 1.5% of the total sample mass. Therefore, the expansion effect through the thickness is extremely slight, and the thickness can be considered essentially unchanged. In other words, the change in thickness of the glass-ceramic before and after chemical strengthening is very small and negligible.

[0086] Glass sheet size measurement: A two-dimensional measuring machine (instrument model: Miyu MY-YXCL-4030) was used for testing.

[0087] XRD testing: The high-lithium-content glass-ceramics or chemically strengthened glass-ceramics of this application were crushed and ground into samples with a particle size of less than 75 μm. The ground samples were tested using an X-ray diffractometer to obtain XRD diffraction peak curves and XRD diffraction data. The X-ray diffractometer used in this application was a Shimadzu XRD-6100, with a 2θ value of 10°-50°, a scanning speed of 6° / min, an operating voltage of 40 kV, and an operating current of 30 mA.

[0088] Determination of crystal phase: XRD diffraction data were analyzed using Jade software (JADE Standard 8.6) to determine the crystal phase composition of the sample.

[0089] Determination of Crystallinity: Import the XRD test results (RAW format) into Jade, an X-ray diffraction data Rietveld refinement software, for fitting and calculation to determine the crystallinity of the sample. Specifically, the ratio of the fitted crystalline phase peak area to the total fitted peak area is recorded as the crystallinity of the sample.

[0090] Determination of average crystal size: Using the result data obtained from the XRD test, the average crystal size of the sample can be calculated according to the Scherrer formula D = Kλ / (βcosθ). Wherein, λ is the X-ray wavelength, λ = 0.154056nm, β is the half-maximum width of the diffraction peak, K = 0.89, and θ is the Bragg diffraction angle. Specifically, the RAW format file output by the XRD instrument is curve fitted in Jade software. Jade outputs a fitting report. Based on the angle 2θ value and Peak FWHM value corresponding to each diffraction peak in the fitting report, the Peak FWHM value is converted to radians: β = (FWHM / 180×3.14). The crystal size of each diffraction peak is calculated using the Scherrer formula D = Kλ / (βcosθ) and then averaged to obtain the average crystal size in the sample.

[0091] Transmittance and optical b-value testing: Referring to the national standard "GB / T 7962.12-2010 Test methods for colorless optical glass Part 12: Spectral transmittance," a haze meter was used to test the transmittance and optical b-value of the high-lithium-content glass-ceramics of this application. Specifically, a haze meter was used to test the transmittance and optical b-value of five glass-ceramics from the same batch for light of different wavelengths. The average optical b-values ​​measured for the five glass-ceramics were taken and recorded as the optical b-value result of the glass-ceramics. The average transmittance of the five glass-ceramics at a wavelength of 550nm was taken and recorded as the transmittance result of the glass-ceramics at a wavelength of 550nm. Among them, the haze meter used in the test of this application is the Konica Minolta spectrophotometer CM-3600A from Japan. The light receiving optical system is transmission, the spectroscopic method is a plane reflective grating, the wavelength range is 360nm-740nm, the wavelength spacing is 10nm, the illumination light source is a pulsed xenon lamp × 4, the ambient temperature of the instrument is 24°C, and the air humidity is 40%.

[0092] Density: This application uses the electronic density balance SD-200L of Japan ALFA MIRAGE to test the density of high lithium content microcrystalline glass.

[0093] Refractive index: This application uses a WYA-2WAJ Abbe refractometer to measure the refractive index of high-lithium content microcrystalline glass.

[0094] Exchange capacity: refers to the ratio of the mass difference of high-lithium-content glass-ceramics before and after chemical strengthening to the mass of high-lithium-content glass-ceramics before chemical strengthening.

[0095] Expansion softening point temperature: The sample is made into a cylinder with a diameter of 5.5 mm and a length of 20 mm. The sample is tested using a thermal expansion instrument LINSEIS L75VD1000. The test output is a thermal expansion coefficient test curve. When the curve begins to decline with increasing temperature, the temperature corresponding to the starting point of the downward trend is taken as the expansion softening point temperature of the sample.

[0096] Young's modulus: The UMS-100 ultrasonic material characterization system was used to test the Young's modulus of high lithium content glass-ceramics by acoustic waves.

[0097] Crystallization Upper Limit Temperature: Break the base glass into small pieces and place them into a long quartz tank, filling the tank completely. Set the temperature range in a JKZC-XJY01 gradient furnace, such as 1050°C-1225°C. Select at least six temperature points in each temperature range, from high to low. Once the gradient furnace reaches the preset temperature range, place the long quartz tank containing the sample into the gradient furnace, adjusting the six temperature points to correspond to the glass samples at six locations within the long quartz tank. Maintain the long quartz tank at a constant temperature within the gradient furnace for 60-70 minutes before removing it. Observe the glass samples at different locations within the long quartz tank using a microscope or magnifying glass. If the glass sample shows devitrification or fogging, it is considered crystallized. If the glass sample is transparent, it is considered non-crystallized. The crystallization upper limit temperature range is between the temperature point corresponding to the transparent sample and the temperature point corresponding to the adjacent devitrified or foggy sample. The average of these two temperature points is the crystallization upper limit temperature. If all or none of the glass samples in the long quartz tank crystallize within the temperature range set by the gradient furnace, the temperature range of the gradient furnace is reset and the upper limit temperature of crystallization of the glass samples is measured.

[0098] Average sandpaper drop height test: For multiple chemically strengthened glass-ceramics samples in the same embodiment or the same comparative example, the sandpaper drop height of each sample is added together and divided by the number of samples tested. The value obtained is recorded as the average sandpaper drop height of the tested chemically strengthened glass-ceramics, which is used to characterize the drop damage resistance of the chemically strengthened glass-ceramics. At least 10 samples are taken from each batch for testing, and the average sandpaper drop height is Where n is the number of glass samples tested in each batch, hi is the sandpaper drop resistance height of a single sample test;

[0099] Among them, the test method for a single sample's resistance to sandpaper drop height is:

[0100] Step 1: Apply 80-grit sandpaper to the bottom surface of the 181g model machine and place the model machine on the green figure LT-SKDL-CD drop machine;

[0101] Step 2: Place a chemically strengthened glass-ceramic sample to be tested with a length, width and thickness of 50mm×50mm×0.5mm directly below the model machine, with the chemically strengthened glass-ceramic sample facing the sandpaper. Make the model machine drop from a certain drop height to impact the chemically strengthened glass-ceramic sample directly below the model machine. If the chemically strengthened glass-ceramic sample does not break, increase the drop height of the model machine in a certain pattern, and continue to drop the model machine to impact the chemically strengthened glass-ceramic sample directly below the model machine until the chemically strengthened glass-ceramic sample breaks. For example, the drop height of the model machine starts from 0.4m, and the sample is dropped once. If the sample does not break, the drop height of the model machine is increased by 0.1m, and it falls again. Repeat the above process until the chemically strengthened glass-ceramic sample breaks;

[0102] Step 3: The last drop height of the chemically strengthened glass-ceramic sample before it breaks is recorded as its sandpaper drop height. For example, if the drop height is increased by 0.1m each time, and the drop height of the sample is 0.5m when it breaks, the sandpaper drop height of the sample is 0.4m.

[0103] Without being bound by any theory, it is speculated that the chemical strengthening process of microcrystalline glass usually goes through the following two steps: first, ion exchange occurs at the interface between microcrystalline glass and molten salt, and ions with larger ionic radius in the molten salt enter the microcrystalline glass; second, the large-radius ions exchanged in the microcrystalline glass migrate deeper into the microcrystalline glass. However, when microcrystalline glass with a high lithium content and containing a main crystal phase of lithium disilicate is chemically strengthened in a high-temperature salt bath (e.g., the salt bath temperature is above 480°C), the surface ion exchange (e.g., lithium ions Li in the microcrystalline glass) + With the sodium ion Na in the salt bath + While the rate of exchange (exchange) is relatively fast, the migration rate of large-radius ions entering the glass-ceramic is limited by the internal structure of the glass-ceramic. In this case, the compressive stress generated on the surface of the glass-ceramic will quickly reach its limit, which can easily lead to "surface cracking" on the surface of the glass-ceramic. "Surface cracking" mainly occurs on the first and / or second main surfaces of the glass-ceramic, and the cracks do not penetrate the entire depth or thickness of the glass-ceramic.

[0104] Optionally, when the chemical strengthening treatment is carried out at a higher temperature, the first main surface or / and the second main surface of the microcrystalline glass with a high lithium content and containing a main crystalline phase of lithium disilicate may even be prone to "peeling", that is, the outermost layer will directly fall off from the microcrystalline glass, and the thickness of the detached layer will usually be from a few microns to tens of microns.

[0105] The "surface cracking" and / or "peeling" of the microcrystalline glass that occurs during the chemical strengthening process is very harmful to the performance of the microcrystalline glass itself. It will not only cause the surface of the microcrystalline glass to fail, but also greatly reduce the mechanical strength of the microcrystalline glass, making it unable to meet the requirements of use.

[0106] In view of this, the present application provides a high-lithium-content glass-ceramic suitable for high-temperature chemical strengthening, wherein the primary crystalline phase is lithium disilicate, a chemically strengthened glass-ceramic, and their applications. After high-temperature chemical strengthening, the high-lithium-content glass-ceramic not only overcomes the problems of "surface cracking" and / or surface "peeling," but also enables the production of chemically strengthened glass-ceramics with high stress resistance. By using this high-lithium-content glass-ceramic for high-temperature chemical strengthening to produce chemically strengthened glass-ceramics with high stress levels and high mechanical strength, the efficiency of preparing high-strength chemically strengthened glass-ceramics can be greatly improved.

[0107] As described above, in some embodiments of the present application, a high-lithium-content glass-ceramics is provided, wherein the high-lithium-content glass-ceramics contains a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the high-lithium-content glass-ceramics; in terms of molar percentage of oxides, the composition of the high-lithium-content glass-ceramics includes: SiO2: 41.00mol%-69.50mol%, Al2O3: 0.00mol%-2.00mol%, P2O5: 1.50mol%-3.00mol%, ZrO2: 2.00mol%-6.00mol%, MgO: 0.00mol%-2.00mol%, ZnO :0.00mol%-2.00mol%, Na2O: 0.00mol%-3.00mol%, K2O: 0.00mol%-1.00mol%, Li2O: 27.00mol%-32.00mol%, CaO: 0.00mol%-5.00mol%, B2O3: 0.00mol%-1.00mol%, SrO: 0.00mol%-2.00mol%; in terms of the content expressed in molar percentage of each oxide in the composition of high lithium content microcrystalline glass, the composition of high lithium content microcrystalline glass satisfies: 0.20≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.41.

[0108] In the present application, by optimizing the glass formula, such as using a higher content of zirconium and a lower content of aluminum at a higher content of lithium, and so on, while ensuring that the various components satisfy a specific content relationship and that the various components interact with each other, on the one hand, it is beneficial to ensure the precipitation of the desired content of lithium disilicate crystal phase and limit the precipitation of other crystal phases (such as petalite crystal phase), thereby helping to ensure that a microcrystalline glass with high intrinsic strength and excellent optical properties and with lithium disilicate as the main crystal phase is obtained; on the other hand, it is beneficial to ensure that the microcrystalline glass meets a specific composition and structure, thereby ensuring that it can achieve high-temperature chemical strengthening, ensuring that it will not have "surface cracking" and / or surface "peeling" problems during the high-temperature chemical strengthening process, thereby helping to improve its chemical strengthening efficiency, and can ensure that the chemically strengthened microcrystalline glass prepared thereby has a high stress level (such as high CS_50, |CT_AV|, DOL_0, etc.) and high mechanical strength properties.

[0109] In some embodiments, the value of 2.25×Li2O-8×ZrO2-0.2×CaO can be, for example, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, or 0.41, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0110] In this application, SiO2 is a glass network-forming oxide and an indispensable component of the glass network structure. While appropriately increasing the SiO2 content can enhance the structural stability and mechanical strength of the glass, excessive SiO2 can increase the viscosity of the base glass, making glass melting more difficult and thus reducing the formability of the base glass. Therefore, the molar percentage of SiO2 is controlled within a range of 41.00 mol% to 69.50 mol%, optionally within a range of 60.00 mol% to 65.00 mol%, and more preferably, within a range of 61.00 mol% to 64.00 mol%.

[0111] In some embodiments, the high lithium content glass-ceramics may contain 41.00mol%-69.50mol%, 42.00mol%-69.00mol%, 50.00mol%-68.00mol%, 55.00mol%-66.00mol%, 60.00mol%-69.00mol%, 60.00mol%-65.00mol%, 61.00mol%-69.00mol%, 61.00mol%-64.00mol%, 62.00mol%-64.00mol%, 63.00mol%-64.00mol%, 61.00mol%-63.50mol% or 63.00mol%-69.50mol% SiO2. In some embodiments, the high lithium content glass-ceramics may contain 41.00 mol%, 42.00 mol%, 43.00 mol%, 44.00 mol%, 45.00 mol%, 46.00 mol%, 47.00 mol%, 50.00 mol%, 53.00 mol%, 55.00 mol%, 58.00 mol%, 60.00 mol%, 61.00 mol%, 62.00 mol%, 63.00 mol%, 63.50 mol%, 64.00 mol%, 65.00 mol% or 69.50 mol% of SiO2, or may contain SiO2 within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as a high lithium content microcrystalline glass or chemically strengthened microcrystalline glass with the required performance of the present application can be obtained.

[0112] In this application, Al2O3 is an optional component. The addition of an appropriate amount of Al2O3 helps to promote ion exchange during the chemical strengthening process to a certain extent. However, excessive Al2O3 can increase the viscosity of the glass and easily lead to the precipitation of other crystalline phases, such as petalite, affecting the crystal structure of the microcrystalline glass. Therefore, the molar percentage of Al2O3 is controlled within 0.00mol%-2.00mol%.

[0113] In some embodiments, the high lithium content microcrystalline glass may contain 0.00mol%-2.00mol%, 0.00mol%-1.60mol%, 0.00mol%-1.00mol%, 0.50mol%-1.60mol%, 0.50mol%-1.00mol%, 0.00mol%-0.50mol%, 1.20mol%-1.60mol%, 0.00mol%-1.30mol%, 0.00mol%-1.20mol% or 1.00mol%-2.00mol% Al2O3. In some embodiments, the high-lithium-content glass-ceramics may contain 0.00 mol%, 0.50 mol%, 0.70 mol%, 0.85 mol%, 0.95 mol%, 1.00 mol%, 1.10 mol%, 1.20 mol%, 1.30 mol%, 1.40 mol%, 1.50 mol%, 1.60 mol%, 1.80 mol% or 2.00 mol% of Al2O3, or may contain Al2O3 within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0114] In this application, P2O5 is an essential component as a nucleating agent. When its content is too little or too much, it will lead to poor crystallization effect and affect the optical properties of the obtained microcrystalline glass, such as reducing the transparency of the microcrystalline glass. Therefore, the molar percentage of P2O5 is controlled at 1.50mol%-3.00mol%, optionally, 1.50mol%-2.10mol%.

[0115] In some embodiments, the high lithium content microcrystalline glass may contain 1.50mol%-3.00mol%, 1.60mol%-2.80mol%, 1.50mol%-2.50mol%, 1.60mol%-2.10mol%, 1.70mol%-2.20mol%, 1.50mol%-1.60mol%, 1.70mol%-3.00mol%, 1.60mol%-2.50mol%, 1.70mol%-2.30mol%, 1.80mol%-2.00mol%, 2.00mol%-3.00mol%, 1.80mol%-1.90mol%, 1.60mol%-1.90mol%, 1.70mol%-1.90mol%, 1.75mol%-1.95mol% or 1.50mol%-2.10mol% of P2O5. In some embodiments, the high-lithium-content glass-ceramics may contain 1.50 mol%, 1.60 mol%, 1.70 mol%, 1.75 mol%, 1.80 mol%, 1.85 mol%, 1.95 mol%, 2.00 mol%, 2.10 mol%, 2.20 mol%, 2.30 mol%, 2.40 mol%, 2.50 mol%, 2.60 mol%, 2.80 mol% or 3.00 mol% of PO, or may contain PO within a numerical range consisting of any two of the above-mentioned specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0116] In the present application, ZrO2 is an intermediate oxide in the formation of glass. An appropriate amount of ZrO2 can improve the chemical stability of the glass, increase the hardness of the glass, and the scratch and drop resistance of the glass. At the same time, due to the high cationic charge and strong electric field of ZrO2, it has a large accumulation effect on the glass structure and is often used as a nucleating agent in microcrystalline glass. In the present application, the use of a certain amount of ZrO2 is not only beneficial for the microcrystalline glass to obtain higher stress after chemical strengthening, but also beneficial for the microcrystalline glass to resist "surface cracking" during the strengthening process. However, too high a ZrO2 content will cause the glass to separate or be detrimental to obtaining microcrystalline glass with excellent optical properties. Therefore, the molar percentage of ZrO2 is controlled at 2.00mol%-6.00mol%, and can be optionally 3.00mol%-6.00mol%.

[0117] In some embodiments, the high lithium content glass-ceramics may contain 2.00mol%-6.00mol%, 2.30mol%-5.80mol%, 2.50mol%-5.50mol%, 2.80mol%-5.30mol%, 2.90mol%-5.10mol%, 3.00mol%-5.50mol%, 3.10mol%-4.80mol%, 4.80mol%-6.00mol%, 4.00mol%-5.80mol%, 3.20mol%-5.30mol%, 3.50mol%-5.00mol%, 3.50mol%-6.00mol%, 3.50mol%-5.80mol%, 4.00mol%-5.00mol% or 3.00mol%-6.00mol%. In some embodiments, the high-lithium-content glass-ceramics may contain 2.00 mol%, 2.30 mol%, 2.50 mol%, 2.70 mol%, 2.90 mol%, 3.00 mol%, 3.10 mol%, 3.30 mol%, 3.50 mol%, 4.00 mol%, 4.50 mol%, 5.00 mol%, 5.50 mol%, 5.80 mol% or 6.00 mol% of ZrO2, or may contain ZrO2 within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0118] In the present application, CaO is an optional component of the network exosome oxide formed by the glass. An appropriate amount of CaO helps to reduce the high-temperature viscosity of the glass and increase the density of the glass. However, excessive CaO will shorten the material properties of the glass and increase its brittleness. In the present application, the appropriate addition of a small amount of CaO helps to increase the stress obtained by the micro-ceramics after chemical strengthening, while also slowing down the chemical strengthening rate of the micro-ceramics. Therefore, the molar percentage of CaO is controlled at 0.00mol%-5.00mol%, optionally, at 0.00mol%-4.00mol%.

[0119] In some embodiments, the high lithium content glass-ceramics may contain 0.00mol%-5.00mol%, 0.10mol%-4.00mol%, 0.00mol%-4.00mol%, 0.50mol%-3.80mol%, 0.80mol%-2.00mol%, 0.00mol%-1.60mol%, 0.00mol%-1.00mol%, 1.50mol%-4.00mol%, 0.00mol%-2.00mol%, 1.00mol%-4.00mol% or 0.10mol%-5.00mol% CaO. In some embodiments, the high lithium content glass-ceramics may include 0.00 mol%, 0.10 mol%, 0.50 mol%, 0.70 mol%, 0.85 mol%, 0.95 mol%, 1.00 mol%, 1.10 mol%, 1.20 mol%, 1.30 mol%, 1.40 mol%, 1.50 mol%, 1.60 mol%, 1.80 mol%, 2.00 mol%, 3.00 mol%, 4.00 mol% or 5.00 mol% of CaO, or may include CaO within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0120] In the present application, Li2O is an essential component and a network exo-oxide formed by glass. It not only improves the viscosity of the glass and promotes the melting and clarification of the glass liquid, but is also one of the main components for the formation of lithium disilicate crystals. At the same time, Li2O can also provide alkali metal lithium ions for ion exchange with large-radius ions in the molten salt bath, which is an important factor affecting the stress level that can be obtained by chemically strengthened microcrystalline glass. However, excessive Li2O will deteriorate the optical properties of microcrystalline glass and easily cause the microcrystalline glass to produce "surface cracking" during the strengthening process. Therefore, the molar percentage of Li2O is controlled at 27.00mol%-32.00mol%, optionally, at 27.00mol%-30.00mol%.

[0121] In some embodiments, the high lithium content glass-ceramics may include 27.00mol%-32.00mol%, 27.50mol%-31.00mol%, 27.00mol%-30.00mol%, 27.50mol%-29.50mol%, 28.00mol%-32.00mol%, 28.50mol%-31.00mol%, 29.00mol%-30.50mol%, 28.00mol%-30.50mol% or 29.50mol%-32.00mol% Li2O. In some embodiments, the high-lithium-content glass-ceramics may contain 27.00 mol%, 27.50 mol%, 28.00 mol%, 28.50 mol%, 29.00 mol%, 29.50 mol%, 30.00 mol%, 30.50 mol%, 31.00 mol%, 31.50 mol%, or 32.00 mol% of Li2O, or may contain Li2O within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0122] In this application, MgO is an optional component. An appropriate amount of MgO can regulate the glass phase composition in the microcrystalline glass. However, excessive MgO will affect the growth of the crystal and the crystal phase structure of the microcrystalline glass. Therefore, the molar percentage of MgO is controlled at 0.00mol%-2.00mol%.

[0123] In some embodiments, the high lithium content glass-ceramics may contain 0.00mol%-2.00mol%, 0.00mol%-1.60mol%, 0.50mol%-1.60mol%, 0.80mol%-1.50mol%, 0.00mol%-1.00mol%, 0.00mol%-0.50mol%, 0.10mol%-1.10mol%, 0.10mol%-1.50mol% or 0.00mol%-1.40mol% of MgO. In some embodiments, the high-lithium-content glass-ceramics may include 0.00 mol%, 0.50 mol%, 0.70 mol%, 0.85 mol%, 0.95 mol%, 1.00 mol%, 1.10 mol%, 1.20 mol%, 1.30 mol%, 1.40 mol%, 1.50 mol%, 1.60 mol%, 1.80 mol% or 2.00 mol% of MgO, or may include MgO within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0124] In this application, ZnO, as a network intermediate, is an optional component. An appropriate amount of ZnO can bind free oxygen, adjust the glass structure, and remain in the glass phase of the glass-ceramics, increasing the glass viscosity. However, excessive ZnO can affect crystal growth and the crystalline structure of the glass-ceramics. Therefore, the ZnO mole percentage is controlled within a range of 0.00 mol% to 2.00 mol%.

[0125] In some embodiments, the high lithium content glass-ceramics may contain 0.00mol%-2.00mol%, 0.00mol%-1.70mol%, 0.50mol%-1.60mol%, 0.80mol%-1.50mol%, 0.00mol%-1.00mol%, 0.00mol%-0.50mol%, 0.10mol%-1.10mol%, 0.10mol%-1.50mol% or 0.00mol%-1.40mol% of ZnO. In some embodiments, the high-lithium-content glass-ceramics may include 0.00 mol%, 0.50 mol%, 0.70 mol%, 0.85 mol%, 0.95 mol%, 1.00 mol%, 1.10 mol%, 1.20 mol%, 1.30 mol%, 1.40 mol%, 1.50 mol%, 1.60 mol%, 1.80 mol% or 2.00 mol% of ZnO, or may include ZnO within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0126] In this application, Na2O is an optional component and a network-external oxide. A moderate amount of Na2O provides free oxygen, improves the viscosity of the glass, promotes melting and clarification of the molten glass, and regulates the chemical strengthening rate. However, excessive Na2O not only reduces the crystallinity of the glass-ceramics but also impairs the chemical strengthening effect. Therefore, the molar percentage of Na2O is controlled within a range of 0.00 mol% to 3.00 mol%.

[0127] In some embodiments, the high lithium content glass-ceramics may contain 0.00mol%-3.00mol%, 0.00mol%-2.80mol%, 0.00mol%-1.00mol%, 0.10mol%-2.70mol%, 0.50mol%-1.60mol%, 0.60mol%-1.00mol%, 2.50mol%-3.00mol% or 0.00mol%-0.50mol% of Na2O. In some embodiments, the high-lithium-content glass-ceramics may contain 0.00 mol%, 0.50 mol%, 0.70 mol%, 0.85 mol%, 0.95 mol%, 1.00 mol%, 1.10 mol%, 1.20 mol%, 1.30 mol%, 1.40 mol%, 1.50 mol%, 1.60 mol%, 1.80 mol%, 2.00 mol%, 2.50 mol% or 3.00 mol% of Na2O, or may contain Na2O within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0128] In this application, K2O is an oxide outside the glass network and is an optional component. A moderate amount of K2O can provide free oxygen, increasing the oxygen-to-silicon ratio in the glass structure. However, excessive K2O can affect the glass network structure, impacting the glass's optical properties, thermal stability, chemical stability, mechanical strength, and weatherability. Therefore, the molar percentage of K2O is controlled between 0.00 mol% and 1.00 mol%.

[0129] In some embodiments, the high-lithium-content glass-ceramics may contain 0.00 mol%-1.00 mol%, 0.50 mol%-1.00 mol%, 0.00 mol%-0.50 mol%, 0.85 mol%-1.00 mol%, or 0.00 mol%-0.15 mol% of K2O. In some embodiments, the high-lithium-content glass-ceramics may contain 0.00 mol%, 0.15 mol%, 0.50 mol%, 0.70 mol%, 0.85 mol%, 0.95 mol% or 1.00 mol% of K2O, or may contain K2O within a numerical range consisting of any two of the above-mentioned specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0130] In this application, B2O3 is an optional component. An appropriate amount of B2O3 can be used as a flux and / or softener to help improve the molding and hot bending effects of the glass. However, excessive B2O3 will cause the crystallization process to be uncontrollable, resulting in deterioration of the optical properties of the microcrystalline glass. Therefore, the molar percentage of B2O3 is controlled at 0.00mol%-1.00mol%.

[0131] In some embodiments, the high-lithium-content glass-ceramics may contain 0.00 mol%-1.00 mol%, 0.00 mol%-0.50 mol%, 0.50 mol%-1.00 mol%, 0.10 mol%-0.85 mol%, 0.85 mol%-1.00 mol%, or 0.25 mol%-0.75 mol%. In some embodiments, the high-lithium-content glass-ceramics may contain 0.00 mol%, 0.10 mol%, 0.25 mol%, 0.50 mol%, 0.60 mol%, 0.70 mol%, 0.75 mol%, 0.85 mol%, 0.95 mol% or 1.00 mol% of B2O3, or may contain B2O3 within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics having the required performance of the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as a high lithium content microcrystalline glass or chemically strengthened microcrystalline glass with the required performance of the present application can be obtained.

[0132] In this application, SrO is an optional component and an alkaline earth metal oxide. An appropriate amount of SrO can regulate the glass phase composition in the glass-ceramic, helping to increase the density and Young's modulus of the glass-ceramic. It also helps lower the expansion softening point of the glass-ceramic, thereby facilitating the hot bending of the glass-ceramic into 3D curved glass-ceramics. However, excessive SrO can deteriorate the optical properties of the glass-ceramic. Therefore, the molar percentage of SrO is controlled within a range of 0.00 mol% to 2.00 mol%.

[0133] In some embodiments, the high lithium content glass-ceramics may contain 0.00mol%-2.00mol%, 0.10mol%-2.00mol%, 0.00mol%-1.00mol%, 0.10mol%-1.00mol%, 0.30mol%-1.90mol%, 0.40mol%-1.20mol%, 1.20mol%-2.00mol%, 0.00mol%-0.30mol%, 0.85mol%-1.40mol%, 0.85mol%-1.90mol%, 0.50mol%-1.20mol% or 1.00mol%-2.00mol% SrO. In some embodiments, the high-lithium-content glass-ceramics may contain 0.00 mol%, 0.30 mol%, 0.50 mol%, 0.70 mol%, 0.85 mol%, 0.95 mol%, 1.00 mol%, 1.10 mol%, 1.20 mol%, 1.30 mol%, 1.40 mol%, 1.50 mol%, 1.60 mol%, 1.80 mol% or 2.00 mol% of SrO, or may contain SrO within a numerical range consisting of any two of the above specific numerical values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0134] In some embodiments, the composition of the high lithium content microcrystalline glass includes, in terms of molar percentage of oxides: SiO2: 60.00mol%-65.00mol%, Al2O3: 0.00mol%-2.00mol%, P2O5: 1.50mol%-3.00mol%, ZrO2: 2.00mol%-6.00mol%, MgO: 0.00mol%-2.00mol%, ZnO: 0.00mol%-2.00mol%, Na2O: 0.00mol%-3.00mol%, K2O: 0.00mol%-1.00mol%, Li2O: 27.00mol%-32.00mol%, CaO: 0.00mol%-4.00mol%, B2O3: 0.00mol%-1.00mol%, SrO: 0.00mol%-2.00mol%. By making the microcrystalline glass meet the above composition, it is not only beneficial to give the high-lithium-content microcrystalline glass with lithium disilicate as the main crystal phase high intrinsic strength and excellent optical properties, but also beneficial to ensure its chemical strengthening effect, ensuring that the microcrystalline glass obtains a higher stress level after chemical strengthening, and thus obtains higher mechanical strength and damage resistance.

[0135] In some embodiments, the composition of the high-lithium-content glass-ceramics of the present application may further include other components in addition to the above composition ranges. For example, in some specific embodiments, the composition of the high-lithium-content glass-ceramics may further include, by mole percentage of oxides, the following: Y2O3: 0.00mol%-1.00mol%, La2O3: 0.00mol%-1.00mol%, and Ta2O5: 0.00mol%-1.00mol%.

[0136] In this application, the selective addition of an appropriate amount of Y2O3, La2O3 or Ta2O5 helps to increase the density of the microcrystalline glass and increase its Young's modulus, but it may also increase the refractive index of the microcrystalline glass and reduce the optical properties of the microcrystalline glass. Therefore, the molar percentage of Y2O3, La2O3 or Ta2O5 is controlled at 0.00mol%-1.00mol%.

[0137] In some embodiments, in the high-lithium-content glass-ceramics, the molar percentage of Y2O3, La2O3, or Ta2O5 can be 0.00mol%, 0.10mol%, 0.20mol%, 0.30mol%, 0.40mol%, 0.50mol%, 0.60mol%, 0.70mol%, 0.80mol%, 0.85mol%, 0.90mol%, 0.95mol%, or 1.00mol%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0138] In some embodiments, the composition of the high lithium content glass-ceramics includes, in terms of molar percentage of oxides: SiO2: 60.00mol%-65.00mol%, Al2O3: 0.00mol%-2.00mol%, P2O5: 1.50mol%-2.50mol%, ZrO2: 3.00mol%-6.00mol%, MgO: 0.00mol%-2.00mol%, ZnO: 0.00mol%-2.00mol%, Na2O: 0.00mol%-3.0 0mol%, K2O: 0.00mol%-1.00mol%, Li2O: 27.50mol%-31.00mol%, CaO: 0.00mol%-2.50mol%, B2O3: 0.00mol%-1.00mol%, SrO: 0.00mol%-2.00mol%, Y2O3: 0.00mol%-1.00mol%, La2O3: 0.00mol%-1.00mol%, Ta2O5: 0.00mol%-1.00mol%. By ensuring that the high-lithium content microcrystalline glass meets the above composition, it is beneficial to prepare chemically strengthened microcrystalline glass with a high stress level, and further conducive to ensuring that the prepared chemically strengthened microcrystalline glass has high mechanical strength and excellent damage resistance.

[0139] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics, expressed as the molar percentage of each oxide in the composition, further satisfies the following relationship: 0.25 ≤ (2.2 × ZrO2 + 0.35 × CaO + Na2O) / Li2O ≤ 0.45. By ensuring that the composition of the glass-ceramics satisfies this relationship, the high-lithium-content glass-ceramics can be guaranteed to have high intrinsic strength and excellent optical properties while avoiding surface cracking and / or peeling during chemical strengthening of the glass-ceramics in a high-temperature molten salt bath. In some embodiments, the value of (2.2×ZrO2+0.35×CaO+Na2O) / Li2O can be, for example, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, or 0.45, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0140] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics further satisfies the following, expressed as the molar percentage of each oxide in the high-lithium-content glass-ceramics: 0.00 ≤ (CaO + MgO + ZnO + Na₂O + KO) / (ZrO₂ + Li₂O) ≤ 0.15. Using a composition and structure that satisfies this relationship is more conducive to improving the stress level generated by the high-lithium-content glass-ceramics after chemical strengthening. In some embodiments, the value of (CaO + MgO + ZnO + Na2O + K2O) / (ZrO2 + Li2O) can be, for example, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, or 0.15, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0141] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics further satisfies the following conditions, expressed as the molar percentage of each oxide in the composition of the high-lithium-content glass-ceramics: 0.90≤SiO2+Li2O≤0.95. Adopting a composition and structure that satisfies this relationship is beneficial for ensuring the precipitation of a desired amount of lithium disilicate crystals in the glass-ceramics and can effectively reduce the precipitation of other crystals, such as petalite crystals. This helps ensure that the glass-ceramics obtains higher intrinsic strength and optical properties, and is also beneficial for achieving a high stress level in the glass-ceramics after chemical strengthening. It also helps ensure that the substrate glass does not lose transparency during heat treatment to prepare the glass-ceramics, or that the substrate glass does not lose transparency during the melting process. In some embodiments, the value of SiO2+Li2O can be, for example, 0.900, 0.904, 0.905, 0.910, 0.915, 0.920, 0.925, 0.930, 0.935, 0.940, 0.945, or 0.950, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0142] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics further satisfies the following, expressed as the molar percentage of each oxide in the high-lithium-content glass-ceramics: 2.00 ≤ SiO2 / Li2O ≤ 2.30. Adopting a composition and structure that satisfies this relationship helps reduce the crystal size of the glass-ceramics, thereby improving the optical properties of the glass-ceramics. Furthermore, it helps ensure the precipitation of lithium disilicate crystals, the primary crystalline phase, while effectively reducing the precipitation of other crystalline phases, such as petalite crystals. This helps ensure that the glass-ceramics achieves high intrinsic strength and also helps achieve a high stress level after chemical strengthening. In some embodiments, the value of SiO2 / Li2O can be, for example, 2.00, 2.02, 2.04, 2.06, 2.08, 2.10, 2.12, 2.14, 2.16, 2.18, 2.20, 2.22, 2.24, 2.26, 2.28, or 2.30, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0143] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics, expressed in terms of the molar percentage of each oxide in the composition of the high-lithium-content glass-ceramics, also satisfies the following: 0≤(CaO+SrO) / ZrO2≤1.50. The use of a composition and structure that satisfies this relationship will be more conducive to improving the stress level generated by the high-lithium-content glass-ceramics after chemical strengthening. In some embodiments, the value of (CaO+SrO) / ZrO2 can be, for example, 0.00, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.20, 1.30, 1.40 or 1.50, or can be a value within the numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics having the performance required by the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as a high lithium content microcrystalline glass or chemically strengthened microcrystalline glass with the required performance of the present application can be obtained.

[0144] In some embodiments of the present application, the composition of the high-lithium-content glass-ceramics, expressed in terms of the molar percentage of each oxide in the composition of the high-lithium-content glass-ceramics, also satisfies the following: 0≤Al2O3 / (SiO2+Al2O3)≤0.03. The use of a composition and structure that satisfies this relationship is more conducive to ensuring the precipitation of the main crystalline phase lithium disilicate crystals, and can effectively reduce the precipitation of other crystalline phases, such as petalite crystals, which is conducive to ensuring that the glass-ceramics obtains higher intrinsic strength and optical properties, and is also conducive to enabling the glass-ceramics to obtain a high stress level after chemical strengthening. In some embodiments, the value of Al2O3 / (SiO2+Al2O3) can be, for example, 0.00, 0.01, 0.020, 0.022, 0.023, 0.024, 0.025 or 0.03, or can be a value within the numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as a high lithium content microcrystalline glass or chemically strengthened microcrystalline glass with the required performance of the present application can be obtained.

[0145] In some embodiments, the composition of the high-lithium-content glass-ceramics satisfies the following conditions, based on the content of each oxide in the high-lithium-content glass-ceramics expressed as a molar percentage:

[0146] 0≤(CaO+MgO+ZnO+Na2O+K2O) / (ZrO2+Li2O)≤0.10; and / or,

[0147] 0.90≤SiO2+Li2O≤0.93; and / or,

[0148] 0≤(CaO+SrO) / ZrO2≤1.00, optionally 0≤(CaO+SrO) / ZrO2≤0.70. Ensuring that the composition satisfies at least one of the above relationships further improves the structure of the glass, facilitates the preparation of chemically strengthened glass-ceramics with higher stress levels, and further ensures that the prepared chemically strengthened glass-ceramics have high mechanical strength and excellent damage resistance.

[0149] The high-lithium-content glass-ceramics of the present application have a specific composition and structure that enables high-temperature chemical strengthening. When chemically strengthened in a high-temperature molten salt bath, they do not exhibit surface cracking and / or peeling. In some embodiments of the present application, after treatment in a mixed salt bath at 500°C for 1-5 hours, the X-ray diffraction pattern of the high-lithium-content glass-ceramics exhibits no diffraction peak within the 2θ range of 35.30°-35.90°; wherein the mixed salt bath comprises 29.99wt% NaNO3, 69.98wt% KNO3, and 0.03wt% LiNO3.

[0150] It should be pointed out that after the above-mentioned treatment for 1h-5h, there is no diffraction peak in the range of 2θ of 35.30°-35.90° in the X-ray diffraction pattern of the high-lithium content microcrystalline glass, which means that at any time between 1h-5h of treatment, there is no diffraction peak in the range of 2θ of 35.30°-35.90° in the X-ray diffraction pattern.

[0151] In some embodiments of the present application, the density of the high lithium content glass-ceramics is ρ≥2.54 g / cm 3 , refractive index ≤1.60. High lithium content glass-ceramics that meet this density and refractive index can ensure high intrinsic strength and excellent optical properties.

[0152] In some embodiments, the density ρ of the high lithium content glass-ceramics can be 2.54 g / cm 3 , 2.55g / cm 3 , 2.56g / cm 3 , 2.57g / cm 3 , 2.58g / cm 3 , 2.59g / cm 3 , 2.60g / cm 3 , 2.61g / cm 3 , 2.62g / cm 3 , 2.63g / cm 3 , 2.64g / cm 3 or 2.65g / cm 3, or a value greater than any of the above specific values, or a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the desired performance of the present application can be obtained.

[0153] In some embodiments, the refractive index of the high-lithium-content glass-ceramics can be 1.50, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, or 1.60, or can be a value below any of the above specific values, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0154] In some embodiments of the present application, when the high-lithium-content glass-ceramics is 0.5 mm thick, the b-value of the high-lithium-content glass-ceramics is ≤1.0, and can be optionally ≤0.8. The high-lithium-content glass-ceramics that meets this optical b-value can ensure better optical performance and display effects, and is suitable for use in display screens that require display effects. In some embodiments, at a thickness of 0.5 mm, the b-value of the high-lithium-content glass-ceramics can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0, or can be a value below any of the above-mentioned specific values, or can be a value within the numerical range consisting of any two of the above-mentioned specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that in a specific embodiment, any of the above-mentioned ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0155] In some embodiments of the present application, the high-lithium-content glass-ceramics is transparent in the visible light range, and / or, at a thickness of 0.5 mm, for light with a wavelength of 550 nm, the transmittance of the high-lithium-content glass-ceramics is ≥ 85.00%, optionally, the transmittance is ≥ 90.00%. High-lithium-content glass-ceramics that meet this transmittance can ensure good light transmittance and transparency, and is suitable for use in display screens with requirements for display effects. The "visible light range" here refers to light in the 360 ​​nm-740 nm band.

[0156] In some embodiments, when the high-lithium-content glass-ceramics is 0.5 mm thick, for light with a wavelength of 550 nm, the transmittance of the high-lithium-content glass-ceramics can be 85.00%, 86.00%, 87.00%, 88.00%, 89.00%, 90.00%, 90.50%, 91.00% or 92.00%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0157] The high-lithium-content microcrystalline glass of the present application has a high transmittance and a low b value, which indicates that the high-lithium-content microcrystalline glass of the present application has excellent optical properties and good uniformity, is in a transparent state, and can meet the application requirements of cover glass of electronic equipment.

[0158] In some embodiments of the present application, the crystallinity of the high-lithium content glass-ceramics is 30.00wt%-90.00wt%, optionally, the crystallinity is 50.00wt%-90.00wt%. The "crystallization of the glass-ceramics" here refers to the percentage of the content of all crystalline phases or crystals in the glass-ceramics to the mass of the glass-ceramics. A higher content of microcrystalline phase is beneficial to improving the mechanical strength properties of the glass-ceramics. In some embodiments, the crystallinity of the high-lithium content glass-ceramics can be 30.00wt%-90.00wt%, 45.00wt%-85.00wt%, 50.00wt%-90.00wt%, 55.00wt%-85.00wt%, 60.00wt%-85.00wt%, 65.00wt%-90.00wt%, 70.00wt%-90.00wt% or 68.00wt%-85.00wt%. In some embodiments, the crystallinity of the high-lithium-content glass-ceramics can be 30.00wt%, 35.00wt%, 40.00wt%, 45.00wt%, 50.00wt%, 55.00wt%, 60.00wt%, 65.00wt%, 70.00wt%, 75.00wt%, 80.00wt%, 85.00wt% or 90.00wt%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the required performance of the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the required performance of the present application can be obtained.

[0159] In some embodiments of the present application, "the main crystalline phase is lithium disilicate" or "the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the high lithium content microcrystalline glass" and similar expressions mean that the lithium disilicate crystalline phase accounts for more than 70 weight percent (wt %) of all crystalline phases of the microcrystalline glass according to the embodiment of the present application.

[0160] In some embodiments of the present application, non-limiting examples of other possible crystalline phases in the high-lithium-content glass-ceramics include: a petalite crystalline phase and / or a lithium phosphate crystalline phase. In some embodiments, the high-lithium-content glass-ceramics further comprises a petalite crystalline phase. Optionally, the petalite crystalline phase accounts for ≤20% by weight of the glass-ceramics. More preferably, the petalite crystalline phase may account for ≤15%, ≤10%, or ≤5% by weight of the glass-ceramics.

[0161] In some embodiments of the present application, in high lithium content glass-ceramics, the average crystal size is ≤100nm, optionally, the average crystal size is ≤50nm, more optionally, the average crystal size is 15nm-45nm. Meeting the smaller average crystal size is conducive to ensuring the excellent optical properties of glass-ceramics. In some embodiments, the average crystal size can be 10nm-100nm, 20nm-90nm, 30nm-80nm, 40nm-60nm, 10nm-30nm, 10nm-20nm, 5nm-35nm or 15nm-35nm. In some embodiments, the average crystal size can be 10nm, 15nm, 20nm, 30nm, 40nm, 45nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm, or it can be a numerical value within the numerical range consisting of any two of the above-mentioned specific numerical values ​​as endpoints, as long as the high lithium content glass-ceramics or chemically strengthened glass-ceramics with the required performance of the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as a high lithium content microcrystalline glass or chemically strengthened microcrystalline glass with the required performance of the present application can be obtained.

[0162] In some embodiments of the present application, the upper limit crystallization temperature of the substrate glass corresponding to the high-lithium content glass-ceramics is 1000° C.-1100° C. Meeting this upper limit crystallization temperature range is conducive to the industrial mass production of high-lithium content glass-ceramics.

[0163] In some embodiments of the present application, the Young's modulus of the high lithium content glass-ceramics is ≥100.00GPa, optionally, the Young's modulus of the high lithium content glass-ceramics is ≥110.00GPa, more optionally, the Young's modulus of the high lithium content glass-ceramics is 114GPa-130GPa. Having a higher Young's modulus indicates that the high lithium content glass-ceramics has a higher intrinsic strength, which is beneficial for it to obtain higher mechanical strength properties. In some embodiments, the Young's modulus of the high lithium content glass-ceramics can be 100.00GPa-150.00GPa, 105.00GPa-140.00GPa, 110.00GPa-130.00GPa or 114.00GPa-125.00GPa. In some embodiments, the Young's modulus of the high-lithium-content glass-ceramics can be 100.00 GPa, 105.00 GPa, 110.00 GPa, 114 GPa, 115.00 GPa, 120.00 GPa, 125.00 GPa, 130.00 GPa, 140.00 GPa, or 150.00 GPa, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics or chemically strengthened glass-ceramics with the performance required by the present application can be obtained.

[0164] In some embodiments of the present application, the expansion and softening point of the high-lithium-content glass-ceramics is between 750°C and 820°C. A suitable expansion and softening point is conducive to the 3D hot bending of the high-lithium-content glass-ceramics to obtain 3D curved glass-ceramics with high strength performance. In some embodiments, the expansion and softening point of the high-lithium-content glass-ceramics can be 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, 810°C or 820°C, or can be a value within the numerical range consisting of any two of the above specific values ​​as endpoints, as long as the high-lithium-content glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the high-lithium-content glass-ceramics with the performance required by the present application can be obtained.

[0165] In the present application, the high-lithium content glass-ceramics can be heat-bent to produce 3D curved glass-ceramics. The composition of the 3D curved glass-ceramics is the same or substantially the same as that of the high-lithium content glass-ceramics in terms of molar percentage of oxides.

[0166] The high-lithium-content glass-ceramics of the present application can be prepared by heat-treating a substrate glass. The composition of the substrate glass used is the same or substantially the same as that of the high-lithium-content glass-ceramics in terms of the molar percentage of oxides.

[0167] In this application, the substrate glass can be prepared using conventional molding methods, which are not limited in this application. For example, the molding methods may include, but are not limited to, float, overflow, rolling, or casting. For example, the raw materials and clarifiers may be uniformly mixed (with a uniformity of greater than 98%), melt-molded, and then annealed to produce the substrate glass. Optionally, the process parameters may include a melting temperature of 1480°C to 1680°C, an annealing temperature of 450°C to 650°C, and a holding time of 10 to 48 hours at the annealing temperature. Optionally, the clarifier may include, but is not limited to, one or more of sodium chloride, tin oxide, antimony oxide, or arsenic oxide. The amount of clarifier added may be 0 to 1 wt% of the total amount of the raw materials.

[0168] In the present application, when the substrate glass is heat-treated to prepare a high-lithium content microcrystalline glass, the heat treatment can be carried out in an annealing furnace, for example, and the heat treatment method can include but is not limited to a one-step heat treatment, a two-step heat treatment or a multi-step heat treatment. For example, it can include a two-step heat treatment of a nucleation treatment and then a crystallization treatment. The process conditions of the heat treatment may include but are not limited to: the nucleation temperature can be 500℃-600℃, the nucleation holding time can be 120min-360min; the crystallization temperature can be 600℃-800℃, the crystallization holding time can be 60min-180min; the heating rate of the whole process can be 5℃ / min-20℃ / min, and the cooling rate can be 0.1℃ / min-3℃ / min. After the heat treatment, those skilled in the art can also perform other conventional steps to obtain a high-lithium content microcrystalline glass sample that meets the required specifications or requirements, such as cutting, CNC machining (computer numerical control, i.e., CNC machine tools) or polishing.

[0169] In the present application, a chemically strengthened microcrystalline glass is also provided, wherein the composition at the center of the chemically strengthened microcrystalline glass is the same as the composition of the previous high-lithium content microcrystalline glass, the chemically strengthened microcrystalline glass includes a compressive stress layer region extending from the surface of the chemically strengthened microcrystalline glass to the compression depth, and has tensile stress inside the chemically strengthened microcrystalline glass.

[0170] It should be understood that the composition of the surface of the glass-ceramic product after chemical strengthening may be different from the composition of the glass-ceramic before chemical strengthening (not subjected to the ion exchange process). This is because, during chemical strengthening, one type of alkali metal ion (e.g., Li ion) at the surface of the newly formed glass-ceramic (glass-ceramic before chemical strengthening) + Or Na + ) are replaced by larger alkali metal ions (e.g., Na+ or K + ) is replaced. However, in the embodiments, the glass composition and phase assembly at or near the depth center of the glass-ceramic product still have the composition and phase assembly of the newly formed glass-ceramic. That is, in the present application, the composition (e.g., the composition of the tensile stress layer) and phase assembly at the center of the chemically strengthened glass-ceramic that has been chemically strengthened are the same or substantially the same as those of the newly formed high-lithium glass-ceramic.

[0171] In the present application, the chemically strengthened glass-ceramics contains a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the chemically strengthened glass-ceramics; the composition at the center of the chemically strengthened glass-ceramics, in terms of molar percentage of oxides, includes: SiO2: 41.00mol%-69.50mol%, Al2O3: 0.00mol%-2.00mol%, P2O5: 1.50mol%-3.00mol%, ZrO2: 2.00mol%-6.00mol%, MgO: 0.00mol%-2.00mol%, ZnO: 0.00mol%-2.00mol%, Na2O: 0.00mol%-3.00mol%. mol%, K2O: 0.00mol%-1.00mol%, Li2O: 27.00mol%-32.00mol%, CaO: 0.00mol%-5.00mol%, B2O3: 0.00mol%-1.00mol%, SrO: 0.00mol%-2.00mol%; based on the content of each oxide expressed in molar percentage in the composition at the center of the chemically strengthened microcrystalline glass, the composition at the center of the chemically strengthened microcrystalline glass satisfies: 0.20≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.41, optionally, 0.21≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.39.

[0172] In some embodiments of the present application, the chemically strengthened glass-ceramics has a DOL_0 of 0.20t-0.25t, where DOL_0 is the depth of the compressive stress layer and t is the thickness of the chemically strengthened glass-ceramics. In some embodiments, the depth of the compressive stress layer DOL_0 of the chemically strengthened glass-ceramics can be 0.20t-0.25t, 0.21t-0.24t, 0.21t-0.25t, or 0.22t-0.25t. For example, when the thickness of the chemically strengthened glass-ceramics is 0.5 mm, the DOL_0 of the chemically strengthened glass-ceramics can be 0.100 mm, 0.105 mm, 0.110 mm, 0.112 mm, 0.113 mm, 0.114 mm, 0.115 mm, 0.116 mm, 0.117 mm, 0.118 mm, 0.119 mm, 0.120 mm, 0.121 mm, 0.122 mm, 0.123 mm, 0.124 mm, or 0.125 mm, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics having the desired performance of the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the chemically strengthened glass-ceramics having the desired performance of the present application can be obtained. The DOL_0 of the chemically strengthened microcrystalline glass is within the above range, indicating that the chemically strengthened microcrystalline glass has a high compressive stress layer depth, which is more conducive to offsetting the energy driving crack expansion, thereby ensuring that it has excellent damage resistance, such as excellent drop resistance.

[0173] In some embodiments of the present application, the chemically strengthened glass-ceramics has a |CT_AV| of 80 MPa-200 MPa, where |CT_AV| is the absolute value of the average tensile stress; alternatively, it has a |CT_AV| of 90 MPa-200 MPa. In some embodiments, the chemically strengthened glass-ceramics has a |CT_AV| of 80 MPa-200 MPa, 90 MPa-200 MPa, 90 MPa-180 MPa, 100 MPa-150 MPa, 130 MPa-180 MPa, 80 MPa-100 MPa, 85 MPa-120 MPa, 90 MPa-150 MPa, 95 MPa-180 MPa, 100 MPa-140 MPa, or 120 MPa-140 MPa. In some embodiments, the chemically strengthened glass-ceramics has a |CT_AV| of 80MPa, 90MPa, 100MPa, 110MPa, 120MPa, 130MPa, 140MPa, 150MPa, 160MPa, 170MPa, 180MPa, 190MPa, or 200MPa, or has a |CT_AV| within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics with the performance required by the present application can be obtained. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the chemically strengthened glass-ceramics with the performance required by the present application can be obtained. The |CT_AV| of the chemically strengthened glass-ceramics is within the above range, indicating that the chemically strengthened glass-ceramics has a higher tensile stress level, reflecting that it has a higher surface stress level, and the higher surface compressive stress level can offset more residual energy from falling, squeezing, impact, or collision, thereby ensuring that it has excellent damage resistance.

[0174] In some embodiments of the present application, the chemically strengthened glass-ceramics has a CT_LD of 50,000 MPa / mm-100,000 MPa / mm, where CT_LD is the tensile stress linear density; optionally, it has a CT_LD of 55,000 MPa / mm-100,000 MPa / mm. In some embodiments, the chemically strengthened glass-ceramics has a CT_LD of 50,000 MPa / mm-100,000 MPa / mm, 55,000 MPa / mm-95,000 MPa / mm, 60,000 MPa / mm-90,000 MPa / mm, 65,000 MPa / mm-85,000 MPa / mm, 70,000 MPa / mm-80,000 MPa / mm, 65,000 MPa / mm-100,000 MPa / mm, 60,000 MPa / mm-80,000 MPa / mm, or 60,000 MPa / mm-100,000 MPa / mm. In some embodiments, the chemically strengthened glass-ceramics has a CT_LD of 50,000 MPa / mm, 55,000 MPa / mm, 60,000 MPa / mm, 65,000 MPa / mm, 70,000 MPa / mm, 75,000 MPa / mm, 80,000 MPa / mm, 85,000 MPa / mm, 90,000 MPa / mm, 95,000 MPa / mm, or 100,000 MPa / mm, or has a CT_LD within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. The CT_LD of the chemically strengthened glass-ceramics is within the above range, indicating that the tensile stress stored inside the chemically strengthened glass-ceramics is relatively dense, indicating that the chemically strengthened glass-ceramics has a higher surface stress level, thereby ensuring that it has excellent damage resistance, such as excellent drop resistance.

[0175] In some embodiments of the present application, the chemically strengthened glass-ceramics has a CS_50 of 150 MPa to 280 MPa, where CS_50 refers to the compressive stress value at a depth of 50 μm measured from the main surface of the chemically strengthened glass-ceramics; alternatively, the CS_50 is 160 MPa to 280 MPa. In some embodiments, the chemically strengthened glass-ceramics has a CS_50 of 150 MPa to 280 MPa, 160 MPa to 270 MPa, 165 MPa to 265 MPa, 170 MPa to 260 MPa, 180 MPa to 280 MPa, 165 MPa to 250 MPa, or 180 MPa to 200 MPa. In some embodiments, the chemically strengthened glass-ceramics has a CS_50 of 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa, 260 MPa, 270 MPa, or 280 MPa, or has a CS_50 within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. The CS_50 of the chemically strengthened glass-ceramics is within the above range, indicating that the compressive stress of the chemically strengthened glass-ceramics at a depth of 50 μm from the surface is high, indicating that the chemically strengthened glass-ceramics has a higher surface stress level. The higher the surface compressive stress level, the more residual energy from falling, squeezing, impact or collision can be offset, thereby ensuring that it has excellent damage resistance, such as excellent drop resistance.

[0176] In the present application, by making the chemically strengthened microcrystalline glass meet specific stress characteristics, it can be ensured that the chemically strengthened microcrystalline glass has excellent mechanical strength properties, excellent mechanical strength properties and excellent damage resistance, especially excellent drop damage resistance.

[0177] In some embodiments of the present application, 80 mesh sandpaper is used to perform an anti-sandpaper drop test on a chemically strengthened glass-ceramic with a thickness of 0.5 mm. The average anti-sandpaper drop height of the chemically strengthened glass-ceramic is ≥1.0 m, optionally, the average anti-sandpaper drop height is ≥1.2 m, and more optionally, the average anti-sandpaper drop height is ≥1.5 m. This shows that the chemically strengthened glass-ceramic of the present application has excellent anti-drop performance. In some embodiments, 80 mesh sandpaper is used to perform an anti-sandpaper drop test on a chemically strengthened glass-ceramic with a thickness of 0.5 mm. The average anti-sandpaper drop height of the chemically strengthened glass-ceramic can be 1.0 m, 1.1 m, 1.2 m, 1.3 m, 1.4 m, 1.5 m, 1.6 m, 1.7 m, 1.8 m, 1.9 m, 2.0 m or 2.1 m, etc.

[0178] The chemically strengthened microcrystalline glass of the present application can be obtained by chemically strengthening the high-lithium content microcrystalline glass mentioned above. The chemical strengthening process can be carried out with reference to the process in the prior art, as long as the chemically strengthened microcrystalline glass with the required performance of the present application can be obtained. For example, it may include: first heating the molten salt containing a certain sodium ion concentration to the temperature required for chemical strengthening, and then preheating the high-lithium content microcrystalline glass (for example, a heating rate of 5°C / min-100°C / min can be used during preheating) to the required chemical strengthening temperature and then placing it in the molten salt. After constant temperature treatment until the time required for chemical strengthening is achieved, it is taken out, cooled to room temperature, and the salt attached to the surface is cleaned. After drying, a chemically strengthened microcrystalline glass with a high stress level is obtained.

[0179] In some embodiments of the present application, the temperature of the molten salt bath for chemical strengthening treatment can be 400°C-530°C, and the time of chemical strengthening treatment can be 0.5h-24h, as long as the chemically strengthened microcrystalline glass with the performance required by the present application can be obtained. In some embodiments of the present application, the composition of the molten salt includes 4.8wt%-100wt% sodium salt, 0-95wt% potassium salt and 0-0.2wt% lithium salt in terms of mass ratio. Optionally, the selected sodium salt, potassium salt and lithium salt can be nitrate, sulfate, phosphate or carbonate, etc., as long as the chemically strengthened microcrystalline glass with the performance required by the present application can be obtained. In some embodiments, after the chemical strengthening treatment is completed, when the chemically strengthened microcrystalline glass is cooled, the cooling rate can be 1°C / min-50°C / min. The high-lithium content microcrystalline glass or chemically strengthened microcrystalline glass with excellent performance provided by the present application can be used in electronic devices, including but not limited to mobile phones, tablet computers, handheld game consoles, portable digital devices (such as digital cameras), car-mounted central control, electronic whiteboard glass, smart home, and can also be used in vehicles, aircraft or aircraft, and can also be used in any glass device of desired microcrystalline glass. For example, it can be used for display screens, cover glass, touch screens, glass inner screens or inner frames of electronic devices; for example, it can be used for windshields of vehicles, aircraft or aircraft, such as front windshields or side windshields. For example, it can be used for worktops, other surfaces, appliance doors, floor tiles, wall panels or storage containers. Other surfaces can include but are not limited to exterior wall surfaces, stair tread surfaces, column veneers or counter surfaces, and storage containers can include but are not limited to cups, plates, medicine bottles or beverage bottles.

[0180] The embodiments of the present application are described in detail below. These embodiments are exemplary and are only used to explain the present application. They should not be construed as limiting the present application.

[0181] In the example numbers of the following tables, S refers to an embodiment, such as S1 refers to Example 1; D refers to a comparative example, such as D1 refers to Comparative Example 1.

[0182] Example 1

[0183] (1) Preparation of substrate glass:

[0184] Prepare raw materials with a total mass of 1000g (the raw materials are configured according to the formula of S1 in Table 1, and the proportions of each oxide are shown in Table 2), and add 5g of sodium chloride to the configured raw materials, mix at a speed of 25r / min in a V-type mixer for 30min, and melt in a platinum crucible at 1650℃ for 5h, then pour into a mold to form a glass brick, cool to 900℃, put into a 460℃ annealing furnace for annealing for 12h, and then cool to room temperature with the furnace to obtain the base glass brick.

[0185] (2) Preparation of high-lithium content glass-ceramics: The substrate glass brick was placed in an annealing furnace and heated from room temperature to 525°C at a rate of 10°C / min for nucleation treatment. After being kept at this temperature for 240 minutes, the temperature was then increased to 685°C at a rate of 10°C / min for crystallization treatment. The temperature was kept at this temperature for 60 minutes, and then cooled to room temperature at a rate of 1°C / min to obtain a high-lithium content glass-ceramics sample brick. The composition of the obtained high-lithium content glass-ceramics was the same as that of the substrate glass in terms of molar percentage of oxides, as shown in Tables 1 and 2.

[0186] The obtained high-lithium-content glass-ceramic bricks are subjected to the cold working processes of cutting, CNC machining (the CNC instrument model used in this application is: RCG500S), and polishing in sequence to produce high-lithium-content glass-ceramic samples that meet the required specifications and requirements. In this application, the high-lithium-content glass-ceramic bricks are subjected to the aforementioned cold working processes to produce high-lithium-content glass-ceramic samples with a thickness of 0.50 mm, specifically, to produce 50 mm × 50 mm × 0.50 mm polished glass-ceramic sheet samples.

[0187] Test results of the high lithium content glass-ceramic sample obtained in S1:

[0188] The main crystal phase composition, crystallinity, average crystal size, density, refractive index, Young's modulus of the high lithium content glass-ceramics sample, as well as the optical b value and transmittance (under 550 nm wavelength light) of the high lithium content glass-ceramics sample with a thickness of 0.5 mm were tested respectively, and the results are shown in Table 3.

[0189] (3) Preparation of chemically strengthened microcrystalline glass: The obtained high-lithium content microcrystalline glass sample is placed in the strengthening furnace cavity for preheating for 5 minutes. After preheating, it is quickly placed in 500°C molten salt for chemical strengthening. The composition of the molten salt is 29.99wt% NaNO3+69.98wt% KNO3+0.03wt% LiNO3. After chemical strengthening for 4.75 hours, the glass sample is taken out and placed on the strengthening furnace body to slowly cool to room temperature. The salt wrapped on the glass surface is washed off with clean water. After the glass sample is dried, the chemically strengthened microcrystalline glass can be obtained.

[0190] Test results of chemically strengthened glass-ceramics obtained in S1:

[0191] Ⅰ. Determine whether the chemically strengthened microcrystalline glass has "surface cracks": use 500-2000 lumen light to illuminate the glass surface, as shown in Figure 4. If bright silk cracks are observed, it means that the chemically strengthened microcrystalline glass has "surface cracks"; or if a large number of irregular cracks are observed on the surface of the chemically strengthened microcrystalline glass under an optical microscope, as shown in Figure 4B, it also means that the chemically strengthened microcrystalline glass has "surface cracks", which is recorded as "surface cracks" in appearance. If the aforementioned bright silk cracks and irregular cracks do not exist on the glass surface, it means that the chemically strengthened microcrystalline glass does not have "surface cracks" in appearance, and it is recorded as "good". The effect of the chemically strengthened microcrystalline glass of this embodiment under strong light irradiation is shown in Figure 1, and the morphology of the cross-section of the chemically strengthened microcrystalline glass along the thickness direction under an optical microscope (magnification 200 times) is shown in Figure 3. It can be seen that the aforementioned bright silk cracks do not exist, and there are no irregular cracks inside and on the surface of the glass. The appearance results are recorded as shown in Table 4.

[0192] II. If the chemically strengthened glass-ceramics indicates that there is no "surface cracking", the chemically strengthened glass-ceramics is subjected to an SLP 2000 stress meter (the light source wavelength used is 518 nm, SOC = 25.5 (nm / cm) / MPa, the refractive index is set according to the refractive index value of the glass-ceramics, the refractive index of the high-lithium content glass-ceramics of S1 is 1.5600, and the exposure time is 300 μsec) to measure CS_50, DOL_0, and |CT_AV|; then the tensile stress linear density (CT_LD) value is calculated. The results are shown in Table 4.

[0193] III. The average sandpaper drop resistance of chemically strengthened glass-ceramics was tested. The results are shown in Table 4.

[0194] Example 2-Example 14

[0195] The above steps are respectively carried out with reference to Example 1, except that the raw material composition, different process parameters and corresponding test results of each example are shown in Tables 1 to 4, respectively.

[0196] The effect of the chemically strengthened glass-ceramics of Example 2 under strong light irradiation is shown in FIG2 . There are no bright silk cracks and the appearance quality is good.

[0197] A comparison chart of the XRD spectra of the high-lithium-content microcrystalline glass of Example 4 and the chemically strengthened microcrystalline glass made from the high-lithium-content microcrystalline glass is shown in Figure 10. It can be seen that there is no obvious difference in the XRD spectra of the high-lithium-content microcrystalline glass of Example 4 before and after chemical strengthening treatment.

[0198] In Example 6, the transmittance of the obtained high-lithium-content microcrystalline glass in the 360nm-740nm band is shown in Figure 7, and the X-ray diffraction pattern (i.e., XRD pattern) of the high-lithium-content microcrystalline glass is shown in Figure 8. It can be seen that the main crystalline phase of the high-lithium-content microcrystalline glass is the lithium disilicate crystalline phase, which is transparent in the visible light range and has high transmittance.

[0199] In Example 8, the thermal expansion coefficient test curve of the obtained high-lithium-content microcrystalline glass is shown in Figure 11. It can be seen that the expansion softening point temperature of the high-lithium-content microcrystalline glass is 777°C, indicating that the high-lithium-content microcrystalline glass is easier to perform 3D hot bending.

[0200] Comparative Example 1-Comparative Example 15

[0201] The above methods are respectively carried out with reference to Example 1, except that the raw material composition, different process parameters and corresponding test results of each comparative example are shown in Tables 5 to 8, respectively.

[0202] Among them, the comparison of the XRD patterns of the glass-ceramics before and after chemical strengthening in Comparative Example 1 is shown in Figure 9. It can be seen that after the glass-ceramics in Comparative Example 1 is chemically strengthened in a high-temperature salt bath to obtain chemically strengthened glass-ceramics, the structure undergoes significant changes. Specifically, in the range of 2θ of 35.30°-35.90°, the glass-ceramics before chemical strengthening have no diffraction peaks, but the chemically strengthened glass-ceramics prepared therefrom do have diffraction peaks. The effect of the chemically strengthened glass-ceramics of Comparative Example 1 under strong light irradiation is shown in Figure 4, and the effect under an optical microscope is shown in Figures 4A and 4B. It can be seen that after the glass-ceramics in Comparative Example 1 is chemically strengthened in a high-temperature salt bath, it has the problem of "surface cracking", that is, a large number of "cracks" exist on the surface of the chemically strengthened glass-ceramics obtained.

[0203] The surface of the chemically strengthened microcrystalline glass of Comparative Example 12 exhibits a "peeling" phenomenon, as shown in FIG5 ; the effect under an optical microscope is shown in FIG6 , which shows that the surface is "peeling".

[0204] The chemically strengthened glass-ceramics of Comparative Examples 1-11 all exhibited surface cracking, and the chemically strengthened glass-ceramics of Comparative Example 12 exhibited surface peeling. These chemically strengthened glass-ceramics clearly did not meet the requirements for use, so stress distribution data and exchange capacity testing and calculation were not performed. Because the glass-ceramics of Comparative Example 13 exhibited devitrification (i.e., transmittance at 550 nm was less than 85%), subsequent testing and chemical strengthening were not performed.

[0205] Crystallization upper limit temperature test: In order to analyze the industrial mass production feasibility of the high-lithium-content microcrystalline glass of the present application, the crystallization upper limit temperature of the substrate glass of some embodiments was tested. Among them, the crystallization upper limit temperature of the substrate glass of S3 was 1067.2°C, and the crystallization upper limit temperature of the substrate glass of S4 was 1053.5°C, both lower than 1100°C. The crystallization upper limit temperature was between 1000°C and 1100°C, indicating that the high-lithium-content microcrystalline glass of the present application is conducive to industrial mass production.

[0206] Expansion softening point test: In order to analyze the 3D hot bending effect of the high-lithium-content microcrystalline glass of the present application, the thermal expansion coefficient test curves of the high-lithium-content microcrystalline glass in some embodiments were tested, and the expansion softening point was obtained, as shown in Table 3 for details. From the test results, it can be seen that the expansion softening point of the high-lithium-content microcrystalline glass of the present application is lower than 820°C, and is between 750°C and 820°C, indicating that the high-lithium-content microcrystalline glass of the present application is conducive to 3D hot bending forming to prepare 3D curved microcrystalline glass.

[0207] Table 1 Note: In Table 1, an oxide content of "0" indicates that the component was not actively or intentionally added to the glass composition during the initial batching process, but the component may be present as an impurity.

[0208] Table 2 Note: In Table 2, the content percentages are substituted into the formulas based on the molar percentage of oxides, that is, the molar unit does not participate in the calculation of the formulas.

[0209] Table 3 Note: In Table 3, “ / ” means not tested.

[0210] Table 4

[0211] Table 5 Note: In Table 5, an oxide content of "0" indicates that the component was not actively or intentionally added to the glass composition during the initial batching process, but the component may be present as an impurity.

[0212] Table 6 Note: In Table 6, the content percentages are substituted into the formulas based on the molar percentage of oxides, i.e. the molar unit does not participate in the calculation of the formulas.

[0213] Table 7 Note: In Table 7, “ / ” means not tested.

[0214] Table 8 Note: In Table 8, “ / ” means not tested.

[0215] It can be seen from the results of the embodiments in Tables 1 to 4 and the comparative examples in Tables 5 to 8 that, relative to the comparative examples, the embodiment scheme of the present application, while satisfying the content range of each oxide, also satisfies the composition characteristics of: 0.20≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.41. The obtained high-lithium content microcrystalline glass is suitable for high-temperature chemical strengthening, and can obtain high stress performance after high-temperature chemical strengthening. The chemically strengthened microcrystalline glass will not have "surface cracking" and / or "peeling". At the same time, the chemically strengthened microcrystalline glass has excellent optical properties, has high CS_50, |CT_AV|, DOL_0, CT_LD, and has excellent drop resistance.

[0216] However, in the solutions of Comparative Examples 1 to 15, the glass formulations do not simultaneously meet the oxide content ranges of this application and the composition characteristics of 0.20≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.41. After high-temperature chemical strengthening, the resulting high-lithium-content glass-ceramics either exhibit "surface cracking" and / or "peeling" or have poor optical or stress properties. Specifically, the chemically strengthened glass-ceramics of Comparative Examples 1 to 11 exhibited "surface cracking," the chemically strengthened glass-ceramics of Comparative Example 12 exhibited "peeling," the glass-ceramics of Comparative Example 13 exhibited devitrification and poor optical properties, and the stress properties of Comparative Examples 14 and 15 were poor.

[0217] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, including combining the various technical features in any other appropriate manner. These simple modifications and combinations should also be regarded as the contents disclosed in the present application and fall within the scope of protection of the present application. Industrial Applicability

[0218] The present application ensures that the high-lithium-content microcrystalline glass containing lithium disilicate as the main crystalline phase meets specific composition and structure, especially meets specific oxide content and specific oxide content relationship, which not only ensures that it can achieve high-temperature chemical strengthening and ensures that it will not have "surface cracking" and / or surface "peeling" problems during the high-temperature chemical strengthening process, thereby improving its chemical strengthening efficiency, but also ensures that the chemically strengthened microcrystalline glass prepared by it has a high stress level (such as high CS_50, |CT_AV|, DOL_0, etc.) and high mechanical strength performance. The high-lithium-content microcrystalline glass of the present application can be used to produce chemically strengthened microcrystalline glass with both excellent optical properties and excellent mechanical strength properties, which is conducive to broadening its application scenarios and application fields.

Claims

1. A high lithium content glass-ceramic, characterized in that: The high-lithium-content glass-ceramics comprises a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the high-lithium-content glass-ceramics; Measured in mole percentage of oxides, the composition of the high lithium content glass-ceramics includes: SiO2: 41.00mol%-69.50mol%, Al2O3: 0.00mol%-2.00mol%, P2O5: 1.50mol%-3.00mol%, ZrO2: 2.00mol%-6.00mol%, MgO: 0.00mol%-2.00mol%, ZnO: 0.00mol%-2.00mol%, Na2O: 0.00mol%-3.00mol%, K2O: 0.00mol%-1.00mol%, L i2O: 27.00mol%-32.00mol%, CaO: 0.00mol%-5.00mol%, B2O3: 0.00mol%-1.00mol%, SrO: 0.00mol%-2.00mol%; The composition of the high-lithium-content microcrystalline glass satisfies the following conditions: 0.20≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.41, optionally, 0.21≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.39, expressed as the molar percentage of each oxide in the high-lithium-content microcrystalline glass composition.

2. The high lithium content glass-ceramics according to claim 1, characterized in that: The composition of the high-lithium-content microcrystalline glass also satisfies the following conditions, expressed in terms of the molar percentage of each oxide in the composition: 0.25≤(2.2×ZrO2+0.35×CaO+Na2O) / Li2O≤0.45; optionally, 0.27≤(2.2×ZrO2+0.35×CaO+Na2O) / Li2O≤0.

43.

3. The high lithium content glass-ceramics according to claim 1 or 2, characterized in that: The composition of the high-lithium-content microcrystalline glass satisfies the following conditions, expressed as the molar percentage of each oxide in the composition: 0≤(CaO+MgO+ZnO+Na2O+K2O) / (ZrO2+Li2O)≤0.15; and / or, 0.90≤SiO2+Li2O≤0.95; and / or, 2.00≤SiO2 / Li2O≤2.30; and / or, 0≤(CaO+SrO) / ZrO2≤1.50; and / or, 0≤Al2O3 / (SiO2+Al2O3)≤0.

03.

4. The high lithium content glass-ceramics according to any one of claims 1 to 3, characterized in that Measured in mole percentage of oxides, the high lithium content glass-ceramics comprises: The content of SiO2 is 60.00mol%-65.00mol%, optionally, the content of SiO2 is 61.00mol%-63.50mol%; and / or, The content of Li2O is 27.50mol%-31.00mol%, optionally, the content of Li2O is 28.00mol%-30.50mol%; and / or, The content of ZrO2 is 3.00mol%-6.00mol%, optionally, the content of ZrO2 is 3.50mol%-6.00mol%; and / or, The content of P2O5 is 1.50mol%-2.50mol%, optionally, the content of P2O5 is 1.60mol%-2.10mol%; and / or, The content of CaO is 0.00 mol% to 4.00 mol%. Alternatively, the content of CaO is 0.00 mol% to 2.00 mol%.

5. The high lithium content glass-ceramics according to any one of claims 1 to 4, characterized in that: Calculated in molar percentage of oxides, the composition of the high-lithium content microcrystalline glass also includes: Y2O3: 0.00mol%-1.00mol%, La2O3: 0.00mol%-1.00mol%, Ta2O5: 0.00mol%-1.00mol%.

6. The high lithium content glass-ceramics according to any one of claims 1 to 5, characterized in that: The composition of the high-lithium-content microcrystalline glass satisfies the following conditions, expressed as the molar percentage of each oxide in the composition of the high-lithium-content microcrystalline glass: 0≤(CaO+MgO+ZnO+Na2O+K2O) / (ZrO2+Li2O)≤0.10; and / or, 0.90≤SiO2+Li2O≤0.93; and / or, 0≤(CaO+SrO) / ZrO2≤1.00, optionally, 0≤(CaO+SrO) / ZrO2≤0.

70.

7. The high lithium content glass-ceramics according to any one of claims 1 to 6, characterized in that: The density of the high lithium content glass-ceramics is ρ≥2.54g / cm 3 , refractive index ≤1.

60.

8. The high lithium content glass-ceramics according to any one of claims 1 to 7, characterized in that: At a thickness of 0.5 mm, the b value of the high lithium content glass-ceramics is ≤1.0, optionally, the b value is ≤0.8; and / or, The high lithium content glass-ceramics is transparent in the visible light range, and / or When the thickness is 0.5 mm, for light with a wavelength of 550 nm, the transmittance of the high-lithium-content glass-ceramics is ≥85.00%, and optionally, the transmittance is ≥90.00%.

9. The high lithium content glass-ceramics according to any one of claims 1 to 8, characterized in that: The high lithium content glass-ceramics has a crystallinity of 30.00 wt% to 90.00 wt%, optionally, a crystallinity of 50.00 wt% to 90.00 wt%; and / or, In the high-lithium content glass-ceramics, the average crystal size is ≤100 nm, optionally, the average crystal size is ≤50 nm, and further optionally, the average crystal size is 15 nm-45 nm.

10. The high lithium content glass-ceramics according to any one of claims 1 to 9, characterized in that: The Young's modulus of the high-lithium-content glass-ceramics is ≥100.00 GPa. Optionally, the Young's modulus of the high-lithium-content glass-ceramics is ≥110.00 GPa. Further optionally, the Young's modulus of the high-lithium-content glass-ceramics is 114 GPa-130 GPa.

11. A chemically strengthened glass-ceramic, characterized in that: The composition at the center of the chemically strengthened microcrystalline glass is the same as the composition of the high-lithium-content microcrystalline glass described in any one of claims 1-10, and the chemically strengthened microcrystalline glass includes a compressive stress layer region extending from the surface of the chemically strengthened microcrystalline glass to the compression depth, and has tensile stress inside the chemically strengthened microcrystalline glass.

12. The chemically strengthened glass-ceramics according to claim 11, wherein: The chemically strengthened glass-ceramics contains a lithium disilicate crystalline phase, wherein the lithium disilicate crystalline phase has a higher weight percentage than other crystalline phases present in the chemically strengthened glass-ceramics; the composition at the center of the chemically strengthened glass-ceramics, in terms of molar percentage of oxides, includes: SiO2: 41.00mol%-69.50mol%, Al2O3: 0.00mol%-2.00mol%, P2O5: 1.50mol%-3.00mol%, ZrO2: 2.00mol%-6.00mol%, MgO: 0.00mol%-2.00mol%, ZnO: 0.00mol%-2.00mol%, Na2O: 0.00mol%-3.00mol%, K2O: 0.00mol%-1.00mol%, L i2O: 27.00mol%-32.00mol%, CaO: 0.00mol%-5.00mol%, B2O3: 0.00mol%-1.00mol%, SrO: 0.00mol%-2.00mol%; The composition at the center of the chemically strengthened microcrystalline glass satisfies the following requirements, expressed as the molar percentage of each oxide in the composition at the center of the chemically strengthened microcrystalline glass: 0.20≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.41, optionally, 0.21≤2.25×Li2O-8×ZrO2-0.2×CaO≤0.

39.

13. The chemically strengthened glass-ceramics according to claim 11 or 12, characterized in that: The chemically strengthened glass-ceramics has a DOL_0 of 0.20t-0.25t, and optionally, has a DOL_0 of 0.22t-0.25t, where DOL_0 is the depth of the compressive stress layer and t is the thickness of the chemically strengthened glass-ceramics.

14. The chemically strengthened glass-ceramics according to any one of claims 11 to 13, characterized in that: The chemically strengthened glass-ceramics has a |CT_AV| of 80 MPa-200 MPa, where |CT_AV| is the absolute value of the average tensile stress; optionally, it has a |CT_AV| of 90 MPa-200 MPa; further optionally, it has a |CT_AV| of 130 MPa-200 MPa.

15. The chemically strengthened glass-ceramics according to any one of claims 11 to 14, characterized in that The chemically strengthened glass-ceramics has a CT_LD of 50,000 MPa / mm-100,000 MPa / mm, where CT_LD is the tensile stress linear density; optionally, it has a CT_LD of 55,000 MPa / mm-100,000 MPa / mm; further optionally, it has a CT_LD of 65,000 MPa / mm-100,000 MPa / mm.

16. The chemically strengthened glass-ceramics according to any one of claims 11 to 15, characterized in that The chemically strengthened microcrystalline glass has a CS_50 of 150MPa-280MPa, where CS_50 refers to the compressive stress value at a depth of 50μm measured from the main surface of the chemically strengthened microcrystalline glass; optionally, it has a CS_50 of 160MPa-280MPa; further optionally, it has a CS_50 of 180MPa-280MPa.

17. The chemically strengthened glass-ceramics according to any one of claims 11 to 16, characterized in that: Using 80-grit sandpaper, the chemically strengthened microcrystalline glass with a thickness of 0.5 mm was subjected to a sandpaper drop resistance test. The average sandpaper drop resistance height of the chemically strengthened microcrystalline glass was ≥1.0 m. Optionally, the average sandpaper drop resistance height was ≥1.2 m. Further optionally, the average sandpaper drop resistance height was ≥1.5 m.

18. A glass device, characterized in that: The glass device comprises the high-lithium-content glass-ceramics according to any one of claims 1 to 10 or the chemically strengthened glass-ceramics according to any one of claims 11 to 17.

19. An electronic device, characterized in that: The electronic device comprises the high-lithium-content glass-ceramics according to any one of claims 1 to 10 or the chemically strengthened glass-ceramics according to any one of claims 11 to 17.