Chemically strengthened crystallized glass, cover glass, electronic equipment and glass devices

Abstract

This application provides chemically strengthened crystallized glass, cover glass, electronic equipment, and glass devices, and belongs to the field of crystallized glass technology. This application ensures that chemically strengthened crystallized glass can meet high stress levels and achieve good weather resistance by having a surface composition and stress structure of chemically strengthened crystallized glass with lithium disilicate as the main crystalline phase that meets specific requirements, thereby enabling the chemically strengthened crystallized glass to meet application requirements well.

Description

[Technical Field]

[0001] This application belongs to the technical field of crystallized glass, and more specifically relates to chemically strengthened crystallized glass, cover glass, electronic devices, and glass devices.

[0002] Cross-references of related applications This application claims priority based on the Chinese application filed with the China National Intellectual Property Administration on 13 May 2024, titled "Chemically Strengthened Crystallized Glass, Cover Glass, Electronic Devices and Glass Devices," with application number 202410590891.4, the entire contents of which are incorporated into this application by reference. [Background technology]

[0003] Crystallized glass is a solid composite material formed from a base glass through controlled crystal precipitation during the heat treatment process. Crystallized glass contains both a microcrystalline phase and a glass phase. Crystallized glass is generally stronger than ordinary glass materials that do not contain a microcrystalline phase. This is because the microcrystalline phase is stronger than the glass phase, absorbing more energy during fracture, and the microcrystalline phase extends the crack propagation path, preventing crack propagation and thus allowing more impact energy to be dissipated during the fracture process.

[0004] In recent years, crystallized glass has been used in various electronic devices, such as mobile phones, watches, tablets, laptops, e-readers, and other similar devices. Examples of its use as cover glass for electronic devices include display cover glass and back cover glass. In the case of electronic device displays, cover glass is generally required to have relatively good optical performance, a relatively thin thickness, relatively high mechanical properties, and relatively good environmental durability or weather resistance.

[0005] To further improve the mechanical properties of crystallized glass, it is usually necessary to perform chemical strengthening treatment on the crystallized glass. Through ion exchange, chemically strengthened crystallized glass with relatively high stress levels, relatively high mechanical strength performance, and relatively high resistance to breakage is produced.

[0006] In the case of crystallized glass whose main crystalline phase is lithium disilicate, chemical strengthening primarily involves sodium-lithium ion exchange. That is, during the chemical strengthening process, ion exchange occurs between sodium ions in the molten salt bath used for chemical strengthening and lithium ions in the crystallized glass. To obtain chemically strengthened crystallized glass with relatively high mechanical properties, a predetermined amount of sodium ions are introduced into the crystallized glass through ion exchange, and a high stress level is achieved by utilizing the volume difference resulting from ion exchange, thereby improving mechanical strength performance. If the amount of sodium ions introduced through exchange is relatively small, improvement in mechanical strength performance cannot be achieved.

[0007] The content of this part of the application provides background art related to this application and does not necessarily constitute prior art or well-known art. [Overview of the Initiative]

[0008] Crystallized glass with lithium disilicate as its main crystalline phase undergoes sodium-lithium exchange during the chemical strengthening process, which can improve the deep compressive stress and the depth of the compressive stress layer. However, this exchange tends to form a sodium-enriched layer on the surface of the resulting chemically strengthened crystallized glass. While this exchange improves the mechanical properties of the chemically strengthened crystallized glass, the relatively high sodium content on the surface can easily lead to a decrease in the environmental durability or weather resistance of the chemically strengthened crystallized glass. Specifically, if chemically strengthened crystallized glass with a relatively high sodium content on the surface is exposed to a corrosive environment of sweat for a long period of time, or if it is used after being placed in a humid environment, the surface tends to become rougher and less smooth, leading to clouding and the formation of spots or white marks on the surface that cannot be removed by wiping. These conditions reduce the tactile feel when the user touches the screen, and problems such as clouding, whiteness, and spots further significantly reduce the display effect of the chemically strengthened crystallized glass screen, severely impairing its appearance. Furthermore, if spots, cloudiness, or opacity appear in the camera's position, it significantly impairs the photographic quality of the mobile phone.

[0009] This application aims to provide a chemically strengthened crystallized glass in which lithium disilicate is the main crystalline phase, and which satisfies a specific relationship between the surface composition and stress, thereby ensuring a relatively high stress level and relatively high mechanical strength performance, as well as good environmental durability or weather resistance.

[0010] To achieve the above objectives, this application provides the following technical solution.

[0011] In the first embodiment, a chemically strengthened crystallized glass is provided. The chemically strengthened crystallized glass contains a lithium disilicate crystalline phase, the lithium disilicate crystalline phase has a larger mass fraction than other crystalline phases present in the chemically strengthened crystallized glass, the chemically strengthened crystallized glass has a compressive stress layer on its surface and tensile stress internally, and the chemically strengthened crystallized glass is N = n×(CT_LD - 50000) / 10000 satisfies -32.5 < N < 15, preferably satisfies -28.0 ≤ N ≤ 0, more preferably satisfies -20.0 ≤ N ≤ -2.5, where n = (mass fraction of Na2O on the surface of chemically strengthened crystallized glass ÷ mass fraction of K2O on the surface of chemically strengthened crystallized glass) 2 , by XRF measurement, measure the mass fraction of Na2O on the surface of chemically strengthened crystallized glass and the mass fraction of K2O on the surface of chemically strengthened crystallized glass. CT_LD is the tensile stress line density, with the unit of MPa / mm. In the formula N = n×(CT_LD - 50000) / 10000, substitute the data according to the above unit requirements for calculation to obtain the calculation result, and the unit itself is not involved in the calculation.

[0012] The chemically strengthened crystallized glass according to the present application can meet the high stress level and ensure the realization of good weather resistance by satisfying specific crystal phase structures and requirements of N, and the chemically strengthened crystallized glass can well meet the application requirements of the market.

[0013] In an optional embodiment, the chemically strengthened crystallized glass satisfies 45000 MPa / mm ≤ CT_LD ≤ 52000 MPa / mm, preferably satisfies 45900 MPa / mm ≤ CT_LD ≤ 50000 MPa / mm, more preferably satisfies 47500 MPa / mm ≤ CT_LD ≤ 50000 MPa / mm.

[0014] By satisfying an appropriate stress structure, the chemically strengthened crystallized glass can contribute to obtaining a chemically strengthened crystallized glass product with a relatively high stress level, contribute to the improvement of the mechanical strength performance due to the stress structure, and ensure that the chemically strengthened crystallized glass meets excellent damage resistance.

[0015] In an optional embodiment, the value of N is -2.52, -4.07, -4.47, -4.75, -10.59, -11.90 or -12.73, and / or The value of CT_LD is 47517.24 MPa / mm, 48185.39 MPa / mm, 49692.43 MPa / mm, 47636.26 MPa / mm, 47919.69 MPa / mm, 47679.19 MPa / mm or 48097.14 MPa / mm.

[0016] In an optional embodiment, when expressed as the mass fraction of oxides by XRF measurement, the mass fraction of Na2O on the surface of the chemically strengthened and crystallized glass is 5% - 8.5%, preferably 5.5% - 7.5%, and / or When expressed as the mass fraction of oxides by XRF measurement, the mass fraction of K2O on the surface of the chemically strengthened and crystallized glass is 0.7% - 2.0%, preferably 0.7% - 1.5%, and / or When expressed as the mass fraction of oxides, in the composition of the central part or the tensile stress layer of the chemically strengthened and crystallized glass, the mass fraction of Na2O is 3% - 3.5%, preferably the mass fraction of Na2O is 3.1% - 3.2%.

[0017] In an optional embodiment, when expressed as the mass fraction of oxides by XRF measurement, the mass fraction of Na2O on the surface of the chemically strengthened and crystallized glass is 5.30%, 6.12%, 7.00%, 5.21%, 6.32%, 5.17% or 6.36%, and / or When expressed as the mass fraction of oxides by XRF measurement, the mass fraction of K2O on the surface of the chemically strengthened and crystallized glass is 1.25%, 0.81%, 0.77%, 1.24%, 0.80% or 1.26%, and / or When expressed as the mass fraction of oxides, in the composition of the central part or the tensile stress layer of the chemically strengthened and crystallized glass, the mass fraction of Na2O is 3.16% or 3.14%.

[0018] In an optional embodiment, the chemically strengthened and crystallized glass Y = ΔC × ((CT_LD - 50000) / 100) 2 where Y satisfies Y < 60, preferably satisfies Y ≤ 50, and more preferably satisfies Y ≤ 20. Here, ΔC is the difference between the mass fraction of Na2O on the surface of the chemically strengthened crystallized glass and the mass fraction of Na2O at the central part of the chemically strengthened crystallized glass. The mass fraction of Na2O on the surface of the chemically strengthened crystallized glass is measured by XRF measurement. CT_LD is the tensile stress line density, with the unit of MPa / mm. In the formula Y = ΔC × ((CT_LD - 50000) / 100) 2 In 2 , substitute the data according to the above unit requirements for calculation to obtain the calculation result, and the unit itself is not involved in the calculation.

[0019] By the chemically strengthened crystallized glass satisfying a specific crystal phase structure and the requirement of Y, it can contribute to the realization of a high stress level of the chemically strengthened crystallized glass.

[0020] In an alternative embodiment, the value of Y is 0.36, 10.14, 11.58, 11.88, 13.02, 13.25 or 14.84.

[0021] In an alternative embodiment, the chemically strengthened crystallized glass satisfies 75 MPa ≤ |CT_AV| ≤ 120 MPa, preferably satisfies 77 MPa ≤ |CT_AV| ≤ 90 MPa, where |CT_AV| is the absolute value of the average tensile stress, and / or DOL_0 is 0.18t to 0.25t, preferably 0.20t to 0.25t, where DOL_0 is the depth of the compressive stress layer and t is the thickness of the chemically strengthened crystallized glass, and / or CS_50 is 150 MPa to 250 MPa, preferably 160 MPa to 180 MPa, and CS_50 is the compressive stress value at a location 50 μm deep from the main surface of the chemically strengthened crystallized glass.

[0022] By the chemically strengthened crystallized glass satisfying an appropriate stress structure, it can contribute to obtaining a chemically strengthened crystallized glass product having a relatively high stress level, can contribute to the exertion of the improvement of the mechanical strength performance due to the stress structure, and can ensure that the chemically strengthened crystallized glass satisfies excellent damage resistance.

[0023] In one selectable implementation, the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, expressed as the mole fraction of oxides, includes SiO2: 61.50% to 63.40%, Al2O3: 2.75% to 2.99%, P2O5: 0.91% to 1.91%, ZrO2: 4.20% to 4.85%, Na2O: 1.80% to 3.20%, B2O3: 0% to 1.00%, and Li2O: 25.32% to 26.52%.

[0024] By satisfying specific glass composition requirements, it is possible to contribute to obtaining crystallized glass that satisfies specific crystalline phase structures, and to obtaining chemically strengthened crystallized glass that satisfies specific stress structures.

[0025] In one of the selectable implementations, expressed as the mole fraction of oxides, in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, The mole fraction of SiO2 is 61.50% to 63.30%, preferably 62.00% to 62.60%, and / or The mole fraction of P2O5 is 1.20% to 1.91%, preferably 1.30% to 1.60%, and / or The mole fraction of Na2O is 1.85% to 3.05%, preferably 2.20% to 3.00%, and / or The mole fraction of B2O3 is 0-0.65%, and / or the mole fraction of ZrO2 is 4.20-4.60%, and / or The mole fraction of Li2O is 25.52% to 26.52%, and preferably 25.52% to 26.00%.

[0026] In one of the selectable implementations, expressed as the mole fraction of oxides, in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, The mole fraction of SiO2 is 63.26%, 62.35%, or 62.52%, and / or The mole fraction of Al2O3 is 2.87%, 2.94%, or 2.92%, and / or The mole fraction of P2O5 is 1.41% or 1.53%, and / or The mole fraction of ZrO2 is 4.33% or 4.34%, and / or The mole fraction of Na2O is 2.36%, 2.93%, or 2.96%, and / or The mole fraction of Li2O is 25.77%, 25.91%, or 25.73%.

[0027] In one of the selectable embodiments, in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, the mole fractions of Na2O [Na2O], B2O3 [B2O3], and ZrO2 [ZrO2] are: Z = -1.344 × (2.65 - 100 × [Na2O]) 2 The relationship +0.466 × 100 × [B2O3] + 1.203 × 100 × [ZrO2] is satisfied, and Z satisfies 4.80 ≤ Z ≤ 5.35, preferably 5.05 ≤ Z ≤ 5.25, and / or, In the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, the mole fractions of Na2O [Na2O] and B2O3 [B2O3] are: Satisfying 0.90%≦[Na2O]-[B2O3]≦3.10%, preferably 2.00%≦[Na2O]-[B2O3]≦3.00%, more preferably 2.30%≦[Na2O]-[B2O3]≦3.00%, and / or, In the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, the mole fractions of Na2O [Na2O] and Li2O [Li2O] are: The condition 8.55 ≤ [Li2O] / [Na2O] ≤ 13.85 is satisfied, and preferably 8.60 ≤ [Li2O] / [Na2O] ≤ 11.00 is satisfied.

[0028] In one of the selectable implementations, in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, The value of Z is 5.10, 5.09, or 5.12, and / or The [Na2O]-[B2O3] value is 2.36%, 2.93%, or 2.96%, and / or The [Li2O] / [Na2O] values ​​are 10.92, 8.84, or 8.69.

[0029] In one selectable embodiment, the mass of the lithium disilicate crystalline phase accounts for 70% or more of all crystalline phases of the chemically strengthened crystallized glass. Preferably, the mass of the lithium disilicate crystalline phase accounts for 85% or more of all crystalline phases of the chemically strengthened crystallized glass.

[0030] In one selectable embodiment, the average grain size of the chemically strengthened crystallized glass is 40 nm or less, preferably 15 nm to 35 nm, and / or The degree of crystallinity of the chemically strengthened crystallized glass is 45% or more, preferably 45% to 85%, and more preferably 55% to 65%.

[0031] In one selectable embodiment, the chemically strengthened crystallized glass is transparent within the visible light wavelength range, preferably, for a thickness of 0.70 mm, the transmittance of the chemically strengthened crystallized glass at a wavelength of 550 nm is 90.00% or more, preferably, the transmittance is greater than 90.40%, and / or For a thickness of 0.70 mm, the haze of the chemically strengthened crystallized glass is less than 0.30%, preferably less than 0.20%, and / or When the thickness is 0.70 mm, the b value of the chemically strengthened crystallized glass is less than 0.70, and preferably 0.60 or less.

[0032] In one selectable embodiment, the Young's modulus of the chemically strengthened crystallized glass is 100 GPa or more, preferably 105 GPa to 112.50 GPa, and / or The Vickers hardness of the aforementioned chemically strengthened crystallized glass is 650 kgf / mm². 2The above, preferably 650 kgf / mm² 2 ~800 kgf / mm 2 That is the case.

[0033] In one selectable embodiment, the chemically strengthened crystallized glass is planar or curved, and / or the thickness of the chemically strengthened crystallized glass is 0.3 mm to 2 mm, preferably 0.45 mm to 0.8 mm, and / or the chemically strengthened crystallized glass does not contain a petalite crystalline phase.

[0034] In one of the selectable implementations, a high-temperature, high-humidity aging test is performed on the chemically strengthened crystallized glass under conditions of a temperature of 85°C and a relative humidity of 85%, wherein the high-temperature, high-humidity aging time is 240 hours or more, and the high-temperature, high-humidity aging time is the total time from the start of the high-temperature, high-humidity test on the chemically strengthened crystallized glass until spots or cloudy marks that cannot be removed by wiping appear on the chemically strengthened crystallized glass.

[0035] In a second embodiment, a cover glass is provided. The cover glass is prepared from chemically strengthened crystallized glass according to any embodiment of the first embodiment, or the cover glass includes chemically strengthened crystallized glass according to any embodiment of the first embodiment.

[0036] In a third embodiment, an electronic device is provided. The electronic device includes chemically strengthened crystallized glass according to any embodiment of the first embodiment.

[0037] In one selectable embodiment, the electronic device includes a housing assembled outside the electronic device, the housing includes chemically strengthened crystallized glass according to any embodiment of the first aspect.

[0038] In one selectable embodiment, the housing includes a display cover assembled on the front side of the electronic device, the display cover includes chemically strengthened crystallized glass according to any embodiment of the first embodiment.

[0039] In one selectable embodiment, the housing includes a rear cover assembled on the rear side of the electronic device, the rear cover includes chemically strengthened crystallized glass according to any embodiment of the first embodiment.

[0040] In one selectable embodiment, the electronic device further includes a camera assembly located inside the housing, the housing includes a camera protective cover, the camera protective cover covers the camera assembly and includes chemically strengthened crystallized glass according to any embodiment of the first aspect.

[0041] In one selectable embodiment, the electronic device further includes an intermediate frame, the intermediate frame comprising chemically strengthened crystallized glass according to any embodiment of the first embodiment.

[0042] In some embodiments, the housing may be made of chemically strengthened crystallized glass in part or entirely. The electronic device relating to this application uses chemically strengthened crystallized glass according to any embodiment of the first embodiment for one or more of the following: display cover, back cover, camera protective cover, and intermediate frame.

[0043] In a fourth embodiment, a glass device is provided, which includes a chemically strengthened crystallized glass according to any embodiment of the first embodiment.

[0044] One or more of the above-mentioned technical proposals in this application include the following advantages compared to the prior art.

[0045] This application demonstrates that by ensuring that the surface composition and stress structure of chemically strengthened crystallized glass, in which lithium disilicate is the main crystalline phase, satisfy a specific relationship, chemically strengthened crystallized glass can achieve a high stress level and good weather resistance, thereby enabling chemically strengthened crystallized glass to better meet market application requirements.

[0046] To more clearly explain the technical concept of the embodiments of this application, the drawings used in the embodiments are briefly described below. The drawings described are merely examples of some embodiments of this application and do not limit their scope. Those skilled in the art can obtain other relevant drawings based on these drawings without employing inventive ability. [Brief explanation of the drawing]

[0047] [Figure 1] This is the XRD pattern of the crystallized glass according to Example 1. [Figure 2] This is a comparative graph of the transmittance curves of crystallized glass and chemically strengthened crystallized glass according to Example 1 in the wavelength range of 360 nm to 740 nm. [Figure 3] This is a comparative graph of the XRD patterns of crystallized glass and chemically strengthened crystallized glass according to Example 1. [Figure 4] This is a schematic diagram of the front-side structure of an electronic device according to an embodiment of this application. [Figure 5] This is a schematic diagram of the rear structure of an electronic device according to an embodiment of this application. [Figure 6] This is a schematic diagram of the electronic device according to an embodiment of the present application. [Figure 7] These are comparative photographs of the chemically strengthened crystallized glass before and after the high-temperature and high-humidity test according to Example 1. (7a) is the chemically strengthened crystallized glass before the high-temperature and high-humidity test, and (7b) is the chemically strengthened crystallized glass removed after the high-temperature and high-humidity test was performed for 10 days. [Figure 8] These are comparative photographs of the actual chemically strengthened crystallized glass before and after the high-temperature and high-humidity test according to Example 2. (8a) is the chemically strengthened crystallized glass before the high-temperature and high-humidity test, and (8b) is the chemically strengthened crystallized glass removed after the high-temperature and high-humidity test was performed for 10 days. [Figure 9] These are comparative photographs of the chemically strengthened crystallized glass before and after the high-temperature and high-humidity test according to Example 3. (9a) is the chemically strengthened crystallized glass before the high-temperature and high-humidity test, and (9b) is the chemically strengthened crystallized glass removed after the high-temperature and high-humidity test was performed for 10 days. [Figure 10]The images show comparative photographs of chemically strengthened glass before and after the high-temperature and high-humidity test according to Comparative Example 1. (10a) is the chemically strengthened crystallized glass before the high-temperature and high-humidity test, and (10b) is the chemically strengthened crystallized glass removed after the high-temperature and high-humidity test was performed for 10 days. [Figure 11] Comparative photographs of chemically strengthened glass before and after the high-temperature and high-humidity test in Comparative Example 2 are shown, with (11a) being the chemically strengthened crystallized glass before the high-temperature and high-humidity test and (11b) being the chemically strengthened crystallized glass removed after a 10-day high-temperature and high-humidity test. [Modes for carrying out the invention]

[0048] The following describes in detail the implementation of this application using examples. As those skilled in the art will understand, the following examples are for illustrative purposes only and do not limit the scope of this application. Regarding the lack of specific conditions in the examples, it is possible to use conventional conditions or conditions recommended by the manufacturer. For reagents or equipment whose manufacturers are not specified, commercially available conventional products can be used.

[0049] The endpoints of the ranges and any values ​​disclosed herein are not limited to those specific ranges or values, and these ranges or values ​​should be understood to include values ​​close to those ranges or values. In the case of numerical ranges, one or more new numerical ranges can be obtained by combinations of the endpoints of each range, combinations of the endpoints of each range and individual specific values, and combinations of individual specific values, and these numerical ranges should also be considered to be specifically disclosed herein. The terms “optional” and “optional” mean “may or may not be included.” “And / or” as used herein is inclusive; for example, when using “A and / or B,” it may have only A, only B, or both A and B.

[0050] Terminology and testing methods: In this application, crystallized glass is a solid composite material containing both a glass phase and a crystalline phase (also referred to as a microcrystalline phase), prepared by a predetermined controlled heat treatment of a substrate glass. Crystallized glass is also referred to as glass ceramic, microcrystalline glass, crystallized glass, or crystalline glass.

[0051] In this application, chemically strengthened crystallized glass is a solid composite material obtained by chemically strengthening crystallized glass. During the chemical strengthening treatment, alkali metal ions with a large ionic radius (e.g., potassium ions or sodium ions) in the molten salt bath replace alkali metal ions with a small ionic radius (e.g., sodium ions or lithium ions) in the crystallized glass. This creates a volume difference due to ion exchange, resulting in compressive stress on the surface of the crystallized glass.

[0052] In this application, the substrate glass refers to glass that has not undergone nucleation treatment, crystallization treatment, or strengthening treatment, and is also referred to as base glass.

[0053] In this application, the composition of the central region of the chemically strengthened crystallized glass refers to the composition of the central region or region near the center of the depth or thickness of the chemically strengthened crystallized glass, that is, the composition of the region in the chemically strengthened crystallized glass where ion exchange has not occurred. The composition of the central region of the chemically strengthened crystallized glass is the same as or substantially the same as the composition of the unstrengthened crystallized glass used to prepare the chemically strengthened crystallized glass.

[0054] In this application, the visible light wavelength range refers to 360 nm to 740 nm.

[0055] In this application, haze refers to the percentage of the total transmitted light intensity that is at least 2.5° away from the direction of the incident light.

[0056] In this application, the principal crystalline phase (also referred to as the main crystalline phase) refers to a crystalline phase that has a higher weight content (or weight fraction, mass fraction) than other crystalline phases present in crystallized glass or chemically strengthened crystallized glass.

[0057] In this application, the main surface refers to the surface with the largest surface area, for example, the upper or lower surface of a horizontally positioned crystallized glass sheet.

[0058] In this application, crystallinity refers to the percentage of the total mass of the crystalline phase or crystals in crystallized glass or chemically strengthened crystallized glass relative to the mass of the crystallized glass or chemically strengthened crystallized glass, or is also referred to as the total content of the crystalline phase in crystallized glass or chemically strengthened crystallized glass.

[0059] In this application, when light of a certain wavelength is irradiated onto the main surface of crystallized glass or chemically strengthened crystallized glass, reflection, absorption, and transmission of light occur, and the ratio of the intensity of transmitted light to the intensity of incident light is the transmittance.

[0060] In this application, the D65 light source has a color temperature of 6500K, a color rendering index Ra of over 90, and is a light source used to measure the color of an object irradiated with sunlight including the ultraviolet region, exhibiting a broad spectral distribution in the visible light wavelength region.

[0061] In this application, the term "crystallized glass material" refers to a glass material that has reached a certain degree of crystallinity after heat treatment for a certain period of time, but has not reached the target degree of crystallinity, and can further crystallize and reach the target degree of crystallinity when heated.

[0062] In this application, CT_LD refers to the tensile stress linear density, with units of MPa / mm. After crystallized glass is placed in a molten salt bath and subjected to ion exchange, a compressive stress layer is formed on the surface of the crystallized glass, and a tensile stress layer is formed inside. In this application, during the chemical strengthening treatment, alkali metal ions with large radii in the molten salt bath and alkali metal ions with small radii in the crystallized glass undergo ion exchange, thereby forming a compressive stress layer on the surface of the crystallized glass and a tensile stress layer inside the crystallized glass. In other words, the preparation yields chemically strengthened crystallized glass containing a compressive stress layer and a tensile stress layer. In this application, CT_LD is calculated using the following formula.

[0063]

number

[0064] In this application, CS_50 refers to the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened crystallized glass, with units of MPa, and measured using an SLP-2000 stress meter.

[0065] In this application, |CT_AV| refers to the absolute value of the average tensile stress, with units of MPa, and specifically refers to the absolute value of the average value of all tensile stresses in the tensile stress layer, measured using SLP-2000.

[0066] In this application, DOL_0 refers to the depth of the compressive stress layer, specifically the distance from any main surface of the chemically strengthened crystallized glass to a position close to that surface where the compressive stress is zero, and is measured using SLP-2000.

[0067] In this application, the measurement method for the stress performance described above is specifically as follows: When measuring CS_50, DOL_0, and |CT_AV| of chemically strengthened crystallized glass using an SLP-2000 stress meter, the relevant parameters of the stress meter are a light source wavelength of 518 nm, a SOC (photoelastic coefficient) of 26 [(nm / cm) / MPa], a refractive index of 1.56, and an exposure time of 300 μsec. After measuring DOL_0 and |CT_AV|, the tensile stress linear density (CT_LD) value of the chemically strengthened crystallized glass is calculated using the above tensile stress linear density calculation formula.

[0068] In this application, the b value represents the intensity of yellow and blue hues, and is the transmitted light b value in this application. A positive value indicates that the material is bluer.

[0069] In this application, Vickers hardness is a standard for representing the hardness of materials, submitted in 1921 by Robert L. Smith and George E. Sandland of England at Vickers Ltd.

[0070] In this application, the Vickers hardness measurement method is specifically as follows: Crystallized glass or chemically strengthened crystallized glass is prepared into small pieces with a length, width, and thickness of 50 mm × 50 mm × 0.70 mm. Glass test pieces with a clean surface and no visible damage such as scratches, dents, or cracks are selected as measurement samples, and the Vickers hardness is measured using a Vickers hardness tester. The Vickers hardness tester used in this application is a digital display small-load Vickers hardness tester, model number VTD405, manufactured by Beijing Kewei Technology Co., Ltd. The measurement conditions are a load of 300 gf, a loading time of 10 s, and the effectiveness of the indentation conforms to the standard of "GB / T 37900-2019 Test Method for Hardness and Fracture Toughness of Ultrathin Glass - Small Load Vickers Hardness Indentation Method". Three different positions are selected on the surface of the same measurement sample and measured, and the average value of the three measurement results is taken as the Vickers hardness result of the measurement sample.

[0071] In this application, Young's modulus represents the glass's resistance to elastic deformation due to external forces. This application uses the UMS-100 ultrasonic material evaluation system to measure the Young's modulus of crystallized glass using sound waves.

[0072] In this application, nucleation treatment refers to forming stable crystal nuclei in the substrate glass by heat treatment, and crystallization treatment refers to precipitating crystals or crystalline phases in the substrate glass by heat treatment.

[0073] In this application, the thickness of crystallized glass or chemically strengthened crystallized glass is measured by a micrometer. During ion exchange, the total increase in the amount of Na-K and / or Li-Na exchanged generally does not exceed 1.5% of the total sample mass, so the expansion effect in the thickness direction is extremely small, and the thickness can be considered to change almost nothing. That is, the change in the thickness of the crystallized glass before and after chemical strengthening is so small that it is negligible, and the thickness of the crystallized glass and the thickness of the chemically strengthened crystallized glass prepared therefrom are approximately the same.

[0074] In this application, the dimensional specifications of the crystallized glass sheet are measured using a two-dimensional measuring instrument (instrument model number: Miyu MY-YXCL-4030).

[0075] In this application, the crystalline phase, degree of crystallinity, and average grain size of crystallized glass or chemically strengthened crystallized glass are determined by XRD measurement. Specifically, these are as follows:

[0076] (1) XRD measurement: The crystallized glass or chemically strengthened crystallized glass relating to this application is crushed and ground to obtain a sample with a particle size of less than 75 μm. The sample obtained by grinding is measured using an X-ray diffractometer to obtain an XRD diffraction peak curve and XRD diffraction data. In this application, the X-ray diffractometer used is a Shimadzu XRD-6100, the target is copper, 2θ = 10° to 50°, the scan speed is 6° / min, the work voltage is 40kV, and the work current is 30mA.

[0077] (2) Determination of crystalline phase: XRD diffraction data is analyzed using the Jade software (JADE Standard 8.6) to determine the crystalline phase in the sample.

[0078] (3) Determination of crystallinity: The XRD measurement results (RAW format) are imported into Jade software, fitted, and calculated to determine the crystallinity of the sample.

[0079] (4) Determination of average grain size: Using the result data obtained from the XRD measurement, the average grain size (also called the average crystal size) of the sample can be calculated according to Scherrer's equation D = Kλ / (βcosθ). Here, λ is the X-ray wavelength, λ = 0.154056 nm, β is the diffraction peak full width at half maximum, K = 0.89, and θ is the Bragg diffraction angle. Specifically, curve fitting is performed on the RAW file output from the XRD instrument using Jade software, a fitting report is output by Jade, and 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), and then the grain size of each diffraction peak is calculated according to Scherrer's equation D = Kλ / (βcosθ), and the average value is calculated to obtain the average grain size of the sample.

[0080] In this application, the transmittance, haze, and b-value of the crystallized glass relating to this application are measured using a haze meter, with reference to the national standard "GB / T 7962.12-2010 Method for Measuring Colorless Optical Glass Part 12: Spectral Internal Transmittance". Specifically, the transmittance, haze, and b-value of five crystallized glass pieces from the same batch are measured for light of different wavelengths using a haze meter. The average values ​​of the measured b-values ​​and hazes of the five crystallized glass pieces are taken as the b-value result and haze result of the crystallized glass, respectively. The average value of the transmittance of the five measured crystallized glass pieces at a wavelength of 550 nm is calculated and taken as the transmittance result of the crystallized glass at a wavelength of 550 nm. In this application, the haze meter used for measurement is a Konica Minolta CM-3600A spectrophotometer, with a transmission-type light-receiving optical system, a planar diffraction grating as the spectral method, a wavelength range of 360 nm to 740 nm, a wavelength interval of 10 nm, four pulsed xenon lamps as the illumination source, an ambient temperature of 24°C, and an air humidity of 40%.

[0081] In this application, for multiple chemically strengthened crystallized glass samples in the same example or the same comparative example, the sum of the sandpaper drop resistance values ​​measured for each sample, divided by the number of samples measured, is defined as the average sandpaper drop resistance value of the chemically strengthened crystallized glass being measured, and represents the drop damage resistance performance of the chemically strengthened crystallized glass. Specifically, at least 10 samples are measured per batch, and the average sandpaper drop resistance value is,

number

[0082] Here, n is the number of glass samples measured in each batch, and hi is the sandpaper drop height measured for a single sample.

[0083] The method for measuring the sandpaper drop resistance of a single sample is as follows:

[0084] Step 1: Attach 80-mesh sandpaper to the underside of the 181g model machine, and then place the model machine on the LT-SKDL-CD type drop test machine shown in the schematic diagram.

[0085] Step 2: Place a chemically strengthened crystallized glass sample awaiting measurement, with dimensions of 50mm x 50mm x 0.7mm in length, width, and thickness, directly beneath the model machine, facing the sandpaper. Drop the model machine from a fixed height, impacting the chemically strengthened crystallized glass sample located directly beneath it. If the sample does not shatter, increase the drop height of the model machine according to a predetermined rule, and continue dropping the model machine with impact until the sample shatters. For example, if the sample does not shatter after one impact from a model machine drop height of 0.4m, increase the drop height of the model machine by 0.1m and drop it again, repeating this process until the chemically strengthened crystallized glass sample shatters.

[0086] Step 3: The previous drop height at which the chemically strengthened crystallized glass sample shattered is set as the sandpaper-resistant drop height. For example, if the drop height is increased by 0.1m each time, and the sample shattered at a drop height of 0.5m, then the sandpaper-resistant drop height for the sample is 0.4m.

[0087] In this application, the method for measuring the mass fraction of Na2O on the surface of chemically strengthened crystallized glass is as follows: The content of element Na on the surface of the chemically strengthened crystallized glass is measured using an X-ray fluorescence analyzer (XRF), and the mass fraction of Na2O on the surface is obtained by calculation. The equipment used is a Thermo Scientific ARL PERFORM'X, with a Rh (rhodium) target, a tube voltage of 30kV, a current of 80mA, a collimator of 0.40, AxO3 selected as the crystal, an FPC selected as the detector, a measurement range of a circle with a diameter of 29mm, and the X_UQ method in OXSAS analysis software used as the measurement method.

[0088] In this application, the method for measuring the mass fraction of K2O on the surface of chemically strengthened crystallized glass is as follows: The content of element K on the surface of the chemically strengthened crystallized glass is measured using an X-ray fluorescence analyzer (XRF), and the mass fraction of K2O on the surface is obtained by calculation. The equipment used is a Thermo Scientific ARL PERFORM'X, with a Rh (rhodium) target, a tube voltage of 40kV, a current of 60mA, a collimator of 0.15, LiF200 selected as the crystal, an FPC selected as the detector, a measurement range of a circle with a diameter of 29mm, and the X_UQ method in OXSAS analysis software used as the measurement method.

[0089] In this application, XRF measurements were performed without a standard sample, and the concentrations of elements with atomic numbers of 6 or less, or their oxides, in the chemically strengthened crystallized glass were not measured. During measurement, the chemically strengthened crystallized glass sheet was directly cut to an appropriate size (e.g., 34 mm x 34 mm), placed flat in the sample box, covered the measurement hole diameter, and the measurement was performed.

[0090] In this application, the high-temperature, high-humidity aging time of chemically strengthened crystallized glass is tested under conditions of a test temperature of 85°C and a relative humidity of 85%, i.e., a high-temperature, high-humidity aging test is performed, and the weather resistance of the chemically strengthened crystallized glass is expressed based on the results of the high-temperature, high-humidity aging test. The high-temperature, high-humidity aging time is the total time from the start of the high-temperature, high-humidity test of the chemically strengthened crystallized glass until spots or cloudy marks that cannot be removed by wiping appear on the chemically strengthened crystallized glass.

[0091] This application primarily tests whether the high-temperature, high-humidity aging time of chemically strengthened crystallized glass can exceed 240 hours (10 days). Specifically, a chemically strengthened crystallized glass sample is placed in a temperature-humidity cycle test box with a temperature of 85°C and a relative humidity of 85%, and the initial sample placement time is recorded. Then, every 24 hours, the chemically strengthened crystallized glass sample is removed, its surface is wiped with a dust-free cloth, and it is observed whether there are any spots and / or cloudy marks that cannot be removed by wiping. If there are no spots and / or cloudy marks that cannot be removed by wiping, the sample is placed back into the temperature-humidity cycle test box, removed and observed the next time, and after testing the sample for 240 hours, if there are still no spots and / or cloudy marks that cannot be removed by wiping, the sample passes the high-temperature, high-humidity test, is in an OK state, is recorded as passing, and the high-temperature, high-humidity aging time of the chemically strengthened crystallized glass exceeds 240 hours. If spots and / or cloudy marks that cannot be removed by wiping are observed on the sample after 240 hours of measurement with the sample inside, or before 240 hours have passed since the sample was placed inside, the chemically strengthened crystallized glass will not pass the high temperature and high humidity test, will be in an NG state, and will be recorded as a failure, and the high temperature and high humidity expiration time of the chemically strengthened crystallized glass will be less than 240 hours. The temperature and humidity cycle test box used for measurement in this application is the QTH_80C All-in-One Temperature and Humidity Cycle Test Box.

[0092] While not bound by theory, lithium disilicate crystallized glass, which has lithium disilicate as its main crystalline phase, undergoes chemical strengthening primarily through sodium-lithium ion exchange. This can improve the deep compressive stress and the depth of the compressive stress layer in the glass. However, after the exchange, a sodium-enriched layer is easily formed on the surface of the crystallized glass. If the surface has a relatively high sodium content, the environmental durability (also referred to as weather resistance) of the prepared chemically strengthened crystallized glass decreases. If exposed to sweat for a long period or placed in a humid environment and then used continuously, the surface of the chemically strengthened crystallized glass product will become less smooth, rougher, and eventually cloudy, or develop white spots or spots that cannot be removed by wiping. These situations reduce the tactile feel when the user touches the screen, and problems such as cloudiness, white spots, and spots reduce the display effect of the glass screen and impair its appearance. Furthermore, if spots, cloudiness, or white spots occur in the camera area, it significantly impairs the shooting performance of the mobile phone and shortens the lifespan of the equipment. In contrast, if the surface of chemically strengthened crystallized glass obtained by chemical strengthening (ion exchange) contains too little sodium, the compressive stress formed by sodium-lithium ion exchange is relatively low, resulting in reduced mechanical strength of the chemically strengthened crystallized glass, which cannot meet the needs of use.

[0093] In view of this, in order to make the chemically strengthened crystallized glass have good weather resistance while maintaining high stress and excellent mechanical strength performance, the present application provides a chemically strengthened crystallized glass having good weather resistance and high stress. By satisfying a specific relationship between the surface composition and stress of the chemically strengthened crystallized glass having lithium disilicate as the main crystal phase, the present application provides a chemically strengthened crystallized glass having a relatively high stress level, guaranteeing relatively high mechanical strength performance, and good environmental durability or weather resistance. The surface composition may be the substance components or the component distribution of the substance components on the surface of the base glass, crystallized glass or chemically strengthened crystallized glass, and may also be the mass fraction of certain components on the surface of the base glass, crystallized glass or chemically strengthened crystallized glass, the molar fraction of certain components, the mass fraction relationship between two or more substance components, the mass content relationship between two or more substance components, or the molar content relationship between two or more substance components, or combinations thereof. For example, it may be the mass fraction of Na2O on the surface of the chemically strengthened crystallized glass or the mass fraction of K2O on the surface of the chemically strengthened crystallized glass, or the content relationship between Na2O on the surface of the chemically strengthened crystallized glass and K2O on the surface of the chemically strengthened crystallized glass, or the mass fraction relationship between Na2O on the surface of the chemically strengthened crystallized glass and K2O on the surface of the chemically strengthened crystallized glass.

[0094] In some embodiments of the present application, a chemically strengthened crystallized glass is provided. The chemically strengthened crystallized glass contains a lithium disilicate crystal phase, and the mass fraction of the lithium disilicate crystal phase is larger than that of other crystal phases present in the chemically strengthened crystallized glass. The chemically strengthened crystallized glass has a compressive stress layer on the surface and a tensile stress inside. For the chemically strengthened crystallized glass, N=n×(CT_LD - 50000) / 10000 satisfies -32.5 < N < 15, preferably -28.0 ≦ N ≦ 0, and more preferably -20.0 ≦ N ≦ -2.5.

[0095] Here, n = (mass fraction of Na2O on the surface of the chemically strengthened crystallized glass ÷ mass fraction of K2O on the surface of the chemically strengthened crystallized glass) 2The mass fraction of Na2O and K2O on the surface of the chemically strengthened crystallized glass is measured by XRF measurement. CT_LD is the tensile stress linear density, with units of MPa / mm, and the calculation is performed by substituting the data according to the above unit requirements into the formula N=n×(CT_LD-50000) / 10000 to obtain the calculation result, and the units themselves do not participate in the calculation.

[0096] The lithium disilicate (Li2Si2O5) crystalline phase is an orthorhombic crystal based on a [Si2O5] tetrahedral arrangement, with a flattened or plate-like crystal shape. Within the crystallized glass, the presence of lithium disilicate crystals distorts the crack path as cracks pass through the crystal, preventing crack propagation and improving the strength and fracture toughness of the crystallized glass. Furthermore, the lithium disilicate crystal has a refractive index close to that of the glass substrate (for example, the substrate glass used to prepare the crystallized glass in this application), making it an ideal crystalline phase for preparing highly transparent crystallized glass. In this application, the crystallized glass includes a structure with lithium disilicate as the main crystalline phase, which can contribute to achieving high intrinsic strength and excellent optical performance.

[0097] The chemically strengthened crystallized glass described in this application satisfies specific crystalline phase structure and N requirements, thereby ensuring that the chemically strengthened crystallized glass meets high stress levels and achieves good weather resistance, allowing the chemically strengthened crystallized glass to better meet application requirements.

[0098] In some embodiments, the value of N is -30 to 10, -25 to 5, -20 to 0, -15 to -2, or -10 to -2.5, etc. In some embodiments, the value of N is -32.5, -30, -28.4, -28, -26, -24, -22, -20, -18, -16, -14, -12, -10, -8, -6, -4, -2.5, -2, 0, 2, 4, 6, 8, 10, 12, 14, 15, -2.52, -4.07, -4.47, -4.75, -10.59, -11.90, or -12.73, or any value within a range configured with any two of the above specific values ​​as endpoints, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other ranges, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0099] In some embodiments of this application, the chemically strengthened crystallized glass satisfies 45,000 MPa / mm ≤ CT_LD ≤ 52,000 MPa / mm, preferably 45,900 MPa / mm ≤ CT_LD ≤ 50,000 MPa / mm, and more preferably 47,500 MPa / mm ≤ CT_LD ≤ 50,000 MPa / mm. By setting the CT_LD of the chemically strengthened crystallized glass to 45,000 MPa / mm or higher, it contributes to ensuring that the tensile stress accumulated inside the chemically strengthened crystallized glass is sufficiently dense, thus guaranteeing a relatively high surface stress level, contributing to an improvement in mechanical strength performance due to the stress structure, guaranteeing excellent break resistance, for example, guaranteeing excellent resistance to damage from rough surface drops, and meeting market demands.

[0100] In several embodiments, the CT_LD of the chemically strengthened crystallized glass is 45,000 MPa / mm to 50,000 MPa / mm, 45,500 MPa / mm to 49,500 MPa / mm, 46,000 MPa / mm to 49,000 MPa / mm, 46,500 MPa / mm to 48,500 MPa / mm, or 46,000 MPa / mm to 48,000 MPa / mm. In some embodiments, the CT_LD of the chemically strengthened crystallized glass is 45000 MPa / mm, 45900 MPa / mm, 46000 MPa / mm, 47000 MPa / mm, 47517.24 MPa / mm, 48185.39 MPa / mm, 49692.43 MPa / mm, 47636.26 MPa / mm, 47919.69 MPa / mm, 47679.19 MPa / mm, 48097.14 MPa / mm, 48000 MPa / mm, 49000 MPa / mm, 49700 MPa / mm, 50000 MPa / mm, 51000 MPa / mm, or 52000 MPa / mm, or a value within a range configured with any two of the above specific values ​​as endpoints, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other ranges, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0101] In some embodiments of this application, as determined by XRF measurement, the mass fraction of Na2O on the surface of the chemically strengthened crystallized glass is 5% to 8.5%, preferably 5.5% to 7.5%. And / or, as determined by XRF measurement, the mass fraction of K2O on the surface of the chemically strengthened crystallized glass is 0.7% to 2.0%, preferably 0.7% to 1.5%. By satisfying a specific range for the K element or Na element on the surface of the chemically strengthened crystallized glass, the chemically strengthened crystallized glass can achieve a relatively high stress level and good weather resistance.

[0102] In some embodiments, as measured by XRF, the mass fraction of Na2O on the surface of the chemically strengthened crystallized glass, expressed as the mass fraction of oxide, is 5%, 5.30%, 6.12%, 7.00%, 5.21%, 6.32%, 5.17%, 6.36%, 7%, 7.5%, 8%, or 8.5%, or may be a value within a range formed with any two of the above specific values ​​as endpoints, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0103] In some embodiments, as measured by XRF, the mass fraction of K2O on the surface of the chemically strengthened crystallized glass, expressed as the mass fraction of oxide, is 0.7%, 1.25%, 0.81%, 0.77%, 1.24%, 0.80%, 1.26%, 1.5%, 1.8%, or 2.0%, or may be a value within a range formed with any two of the above specific values ​​as endpoints, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0104] In some embodiments of this application, the mass fraction of Na2O in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass is 3% to 3.5%, preferably 3.1% to 3.2%, expressed as an oxide mass fraction. In this application, the mass fraction of Na2O in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass is 3% to 3.5%, that is, the mass fraction of Na2O in the composition of the crystallized glass or substrate glass that has not undergone chemical strengthening treatment for preparing the chemically strengthened crystallized glass is 3% to 3.5%.

[0105] In some embodiments, when expressed as the mass fraction of oxides, in the central portion of the chemically strengthened crystallized glass or in the composition of the tensile stress layer, the mass fraction of Na2O is 3.1% - 3.4%, 3.1% - 3.3% or 3% - 3.2%. In some embodiments, when expressed as the mass fraction of oxides, in the central portion of the chemically strengthened crystallized glass or in the composition of the tensile stress layer, the mass fraction of Na2O is 3%, 3.1%, 3.3%, 3.4%, 3.5%, 3.11%, 3.12%, 3.13%, 3.14%, 3.15%, 3.16%, 3.17%, 3.18%, 3.19% or 3.2%, or it may be a value within the range formed by any two specific values above as endpoints, as long as the chemically strengthened crystallized glass with the required performance of this application can be obtained. In a specific embodiment, any of the above ranges can be combined with any other range, as long as the chemically strengthened crystallized glass with the required performance of this application can be obtained.

[0106] In some embodiments of this application, in the chemically strengthened crystallized glass, the Na ion concentration changes in at least a part of the compressive stress layer and reaches the minimum value at the contact point between the compressive stress layer and the tensile stress layer. The chemically strengthened crystallized glass satisfies Y = ΔC×((CT_LD - 50000) / 100) 2 and satisfies Y < 60, preferably satisfies Y ≤ 50, and more preferably satisfies Y ≤ 20.

[0107] Here, ΔC is the difference between the mass fraction of Na2O on the surface of the chemically strengthened crystallized glass and the mass fraction of Na2O at the central portion of the chemically strengthened crystallized glass, and the mass fraction of Na2O on the surface of the chemically strengthened crystallized glass is measured by XRF measurement. CT_LD is the tensile stress line density, with the unit of MPa / mm. Y = ΔC×((CT_LD - 50000) / 100) 2 In this formula, substitute the data according to the above unit requirements for calculation to obtain the calculation result, and the unit itself is not involved in the calculation.

[0108] In this application, chemically strengthened crystallized glass can contribute to achieving a high stress level in chemically strengthened crystallized glass by satisfying the requirements for a specific crystal phase structure and Y.

[0109] In some embodiments, the value of Y satisfies <60, ≤55, ≤50, ≤45, ≤40, ≤35, ≤30, ≤25, ≤20, ≤15, ≤10, or ≤5. In some embodiments, the value of Y is 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 35, 40, 45, 50, 55, 60, 0.36, 10.14, 11.58, 11.88, 13.02, 13.25, or 14.84, or a value within a range configured with any two of the above specific values ​​as endpoints, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other ranges, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0110] In some embodiments of this application, the chemically strengthened crystallized glass satisfies 75 MPa ≤ |CT_AV| ≤ 120 MPa, preferably 77 MPa ≤ |CT_AV| ≤ 90 MPa, where |CT_AV| is the absolute value of the mean tensile stress. Maintaining the |CT_AV| of the chemically strengthened crystallized glass at an appropriate level contributes to securing a desired tensile stress layer distribution structure and a relatively high surface stress level, which can be offset by a relatively high surface compressive stress level, resulting in more residual energy from drops, compression, punctures, impacts, or collisions, thereby contributing to the assurance of excellent break resistance of the chemically strengthened crystallized glass.

[0111] In some embodiments, the |CT_AV| of the chemically strengthened crystallized glass is 80 MPa to 115 MPa, 85 MPa to 110 MPa, 90 MPa to 105 MPa, or 93 MPa to 102 MPa. In some embodiments, the |CT_AV| of the chemically strengthened crystallized glass is 75 MPa, 80 MPa, 85 MPa, 90 MPa, 95 MPa, 100 MPa, 105 MPa, 110 MPa, 115 MPa, 120 MPa, 78.26 MPa, 79.83 MPa, 84.20 MPa, 79.01 MPa, 80.77 MPa, 77.61 MPa, or 79.23 MPa, or any value within a range configured with any two of the above specific values ​​as endpoints, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0112] In some embodiments of this application, the chemically strengthened crystallized glass has a DOL_0 of 0.18t to 0.25t, preferably 0.20t to 0.25t. DOL_0 is the depth of the compressive stress layer, and t is the thickness of the chemically strengthened crystallized glass. By ensuring that the depth of the compressive stress layer and the thickness of the chemically strengthened crystallized glass satisfy an appropriate proportional relationship, it is possible to ensure that the chemically strengthened crystallized glass has a relatively good stress distribution state, and therefore, it is possible to contribute to improving the mechanical strength performance due to the stress structure.

[0113] In some embodiments, the DOL_0 / t value of the chemically strengthened crystallized glass may be 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, or 0.25, or a value within a range formed with any two of the above specific values ​​as endpoints, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0114] In some embodiments of this application, the chemically strengthened crystallized glass has a CS_50 of 150 MPa to 250 MPa, preferably 160 MPa to 180 MPa. CS_50 refers to the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened crystallized glass. The relatively high surface stress level of the chemically strengthened crystallized glass allows for greater offsetting of residual energy from drops, compression, impacts, or collisions, thereby contributing to the assurance of excellent break resistance, such as excellent drop resistance.

[0115] In some embodiments, the CS_50 of the chemically strengthened crystallized glass is 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa, 162.81 MPa, 166.33 MPa, 170.25 MPa, 165.17 MPa, 169.43 MPa, 167.89 MPa, 170.28 MPa, or 200 MPa, or any value within a range configured with any two of the above specific values ​​as endpoints, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0116] The chemically strengthened crystallized glass according to this application is prepared by chemically strengthening crystallized glass, and unless excessive ion exchange treatment is performed, the composition and phase aggregate of the portion of the chemically strengthened crystallized glass deeper than the depth of the compressive stress layer (DOL), for example, the central part of the chemically strengthened crystallized glass or the tensile stress layer, is the same as or approximately the same as the composition and phase aggregate of the crystallized glass. Compared to crystallized glass before chemical strengthening treatment (during which ion exchange is performed), the surface composition of the crystallized glass product after chemical strengthening treatment may differ from the composition of the crystallized glass before chemical strengthening treatment. This is because, during chemical strengthening treatment, one type of alkali metal ion (e.g., Li) is present on the surface of the newly formed crystallized glass. + or Na +) are relatively large alkali metal ions (for example, Na + or K + ) is replaced by ). However, in the embodiment, the composition and phase aggregate of the glass at the center of the depth or thickness of the crystallized glass product or at a location close to the center of the depth or thickness still has the composition and phase aggregate of the newly formed crystallized glass. In other words, in this application, the composition and phase aggregate of the center of the chemically strengthened crystallized glass prepared through chemical strengthening treatment or the composition and phase aggregate of the tensile stress layer are the same as or substantially the same as that of crystallized glass that has not undergone chemical strengthening treatment.

[0117] In this application, the crystallized glass used to prepare the chemically strengthened crystallized glass is prepared by heat-treating a base glass, and in terms of the mole fraction of oxides, the composition of the base glass and the composition of the crystallized glass are the same or approximately the same.

[0118] In some embodiments of this application, the composition of the central region or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the substrate glass, expressed as the mole fraction of oxides, includes SiO2: 61.50% to 63.40%, Al2O3: 2.75% to 2.99%, P2O5: 0.91% to 1.91%, ZrO2: 4.20% to 4.85%, Na2O: 1.80% to 3.20%, B2O3: 0% to 1.00%, and Li2O: 25.32% to 26.52%. By satisfying a specific glass composition, it is possible to obtain a crystallized glass that satisfies a specific crystalline phase structure, and to obtain a chemically strengthened crystallized glass that satisfies a specific stress structure. In specific embodiments, any of the above ranges can be combined with any other ranges, as long as a chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0119] In this application, SiO2 is an essential component for forming the glass network structure and is one of the main components for forming lithium disilicate crystals. In glass systems, the higher the SiO2 content, the denser the network structure of the glass phase becomes, and accordingly, the higher the mechanical strength of the crystallized glass, the lower the coefficient of thermal expansion, and the better the heat resistance, dielectric properties, and chemical stability. If the SiO2 content is too high, the melting temperature of the base glass becomes relatively high, the melt viscosity becomes relatively high, and the difficulty of molding the base glass increases. If the SiO2 content is too low, the weather resistance of the glass decreases. Therefore, in order to combine the formability of the glass with excellent performance, in this application, the mole fraction of SiO2 in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass is 61.50% to 63.40%, preferably 61.50% to 63.30%, and more preferably 62.00% to 62.60%.

[0120] In some embodiments of this application, the SiO2 content in the composition of the central or tensile stress layer of the chemically strengthened crystallized glass, the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, expressed as the mole fraction of oxides, is 62.87%, 62.88%, 63.25%, 63.26%, 62.38%, 62.27%, 62.44%, 62.45%, 62.22%, 63.17%, 61.50%, 61.60%, 61.70%, and 61.80%. , 61.90%, 62.00%, 62.10%, 62.20%, 62.30%, 62.40%, 62.50%, 62.60%, 62.70%, 62.80%, 62.90%, 63.00%, 63.10%, 63.20%, 63.30%, 63.40%, 62.35%, or 62.52%, or any value within a range formed with any two of the above specific values ​​as endpoints, as long as crystallized glass or chemically strengthened crystallized glass with the performance required for this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as crystallized glass or chemically strengthened crystallized glass with the performance required for this application can be obtained.

[0121] In this application, Al2O3 is a component that forms the glass network structure. An appropriate amount of Al2O3 can contribute to improving the chemical strengthening effect of crystallized glass, improving the weather resistance of the glass, and to some extent promoting ion exchange during the chemical strengthening process. However, an excess of Al2O3 leads to an increase in glass viscosity and makes it easier for other crystalline phases such as petalite to precipitate, affecting the crystalline phase structure of the crystallized glass. Therefore, in order to obtain the desired crystalline phase structure and improve the chemical strengthening effect of crystallized glass, in this application, the mole fraction of Al2O3 in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass is 2.75% to 2.99%.

[0122] In some embodiments of this application, the Al2O3 content in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, expressed as a mole fraction of oxides, is 2.75%, 2.77%, 2.79%, 2.81%, 2.83%, 2.85%, 2.86%, 2.87%, 2.89%, 2.91%, 2.93%, 2.94%, 2.95%, 2.97%, 2.99%, or 2.92%, or may be a value within a range formed with any two of the above specific values ​​as endpoints, as long as a crystallized glass or chemically strengthened crystallized glass with the required performance of this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as a crystallized glass or chemically strengthened crystallized glass with the required performance of this application can be obtained.

[0123] In this application, P2O5, as a nucleating agent, can promote uniform nucleation of glass. If the content is too low or too high, the crystallization effect decreases, impairing the optical performance of the resulting crystallized glass and leading to a decrease in the transparency of the crystallized glass. Therefore, in order to obtain the desired crystalline phase structure and achieve excellent optical and mechanical strength performance, in this application, the mole fraction of P2O5 in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass is 0.91% to 1.91%, preferably 1.20% to 1.91%, and more preferably 1.30% to 1.60%.

[0124] In some embodiments of this application, the P2O5 content in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, expressed as a mole fraction of oxides, is 0.91%, 0.95%, 1.00%, 1.05%, 1.10%, 1.15%, 1.20%, 1.25%, 1.30%, 1.35%, 1.40%, 1.45%, 1.50%, 1.55%, 1.60%, 1.65%, 1.70%, 1.75%, 1.80%, 1.85%, 1.41%, 1.53%, 1.54%, or 1.91%, or may be a value within a range formed with any two of the above specific values ​​as endpoints, as long as a crystallized glass or chemically strengthened crystallized glass with the required performance of this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other ranges, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0125] In this application, ZrO2 is an intermediate oxide in glass formation. An appropriate amount of ZrO2 can improve the chemical stability of crystallized glass, improve its hardness, scratch resistance, and drop resistance, and improve its weather resistance. Furthermore, the cations of ZrO2 have a high charge, a strong electric field, and a relatively large cohesive effect on the glass structure, and are often used as nucleating agents in crystallized glass. However, if the ZrO2 content is too high, it can lead to phase separation of the glass or is unfavorable for obtaining crystallized glass with excellent optical performance. Therefore, in order to obtain crystallized glass with excellent optical performance and high mechanical strength, in this application, the mole fraction of ZrO2 in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, or in the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or in the composition of the base glass, is 4.20% to 4.85%, preferably 4.20% to 4.60%.

[0126] In some embodiments of this application, the ZrO2 content in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the substrate glass, expressed as a mole fraction of oxides, is 4.20%, 4.35%, 4.40%, 4.45%, 4.50%, 4.55%, 4.60%, 4.65%, 4.70%, 4.75%, 4.74%, 4.84%, 4.33%, 4.34%, 4.85%, or 4.80%, or may be a value within a range formed with any two of the above specific values ​​as endpoints, as long as a crystallized glass or chemically strengthened crystallized glass with the required performance of this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as a crystallized glass or chemically strengthened crystallized glass with the required performance of this application can be obtained.

[0127] In this application, Na2O is a network-modifying oxide, and an appropriate amount of Na2O can provide free oxygen, improve the viscosity of the glass, promote the melting and clarification of the molten glass, and adjust the rate of chemical strengthening. Excessive Na2O leads to a decrease in the crystallinity of the crystallized glass and impairs the chemical strengthening effect of the crystallized glass. Therefore, in order to improve the formability of the base glass and the chemical strengthening effect of the crystallized glass, in this application, the mole fraction of Na2O in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass is 1.80% to 3.20%, preferably 1.85% to 3.05%, and more preferably 2.20% to 3.00%.

[0128] In some embodiments of this application, the Na2O content in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, expressed as the mole fraction of oxides, is 1.80%, 1.85%, 1.90%, 1.95%, 2.00%, 2.05%, 2.10%, 2.15%, 2.20%, 2.25%, 2.30%, 2.35%, 2.40%, The values ​​may be 2.45%, 2.50%, 2.55%, 2.60%, 2.65%, 2.70%, 2.75%, 2.80%, 2.85%, 2.90%, 2.95%, 3.00%, 3.20%, 2.36%, 2.96%, 3.01%, 2.93%, or 3.05%, or any of the above values ​​may be within a range formed with any two specific values ​​as endpoints, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0129] In this application, B2O3, as a flux, can lower the high-temperature viscosity of glass, improve the problem of difficulty in melting due to ZrO2, and lower the softening temperature of glass. However, excessive B2O3 tends to lead to a decrease in the transparency of crystallized glass. Also, depending on the B2O3 content, the structure formed will differ, which has a relatively large effect on the weather resistance of the glass. Specifically, B 3+ When the ion content is relatively low, B 3+ The ions are located in the [BO4] tetrahedron and can reconnect bonds that have been broken by alkali metal ions in the glass, contributing to improved weather resistance. As the B2O3 content increases, B 3+ The ion structure changes to a [BO3] trigonal pyramidal shape, and conversely, the weather resistance decreases. For this reason, in order to improve the moldability of the base glass and to obtain crystallized glass with the desired performance, in this application, the mole fraction of B2O3 in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass is 0 to 1.00%, preferably 0 to 0.65%.

[0130] In some embodiments of this application, the B2O3 content in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, expressed as a mole fraction of oxides, is 0, 0.05%, 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, 0.55%, 0.65%, 0.70%, 0.80%, 0.90%, 1.00%, or 0.60%, or may be a value within a range formed with any two of the above specific values ​​as endpoints, as long as a crystallized glass or chemically strengthened crystallized glass with the required performance of this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as a crystallized glass or chemically strengthened crystallized glass with the required performance of this application can be obtained.

[0131] In this application, Li2O is an essential component for forming the lithium disilicate crystal phase, which is the main crystalline phase, and is also an essential component for providing lithium ions for ion exchange during the chemical strengthening process. An appropriate amount of Li2O can improve the viscosity of the glass, contribute to promoting the melting and clarification of the molten glass, and contribute to ensuring that lithium disilicate crystals of the desired content are obtained. Furthermore, Li2O can provide alkali metal lithium ions for ion exchange with large radius ions (e.g., sodium ions) in the molten salt bath, and is one of the factors that influence the stress level that can be obtained in chemically strengthened crystallized glass. However, if there is an excess of Li2O, the optical performance of the crystallized glass will decrease. Therefore, in order to improve the moldability of the base glass and improve the crystallized glass with a desired structure, and to improve the chemical strengthening effect of the crystallized glass, in this application, the mole fraction of Li2O in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass is 25.32% to 26.52%, preferably 25.52% to 26.52%, and more preferably 25.52% to 26.00%.

[0132] In some embodiments of this application, the Li2O content in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, expressed as the mole fraction of oxides, is 25.32%, 25.52%, 25.60%, 25.65%, 25.70%, 25.75%, 25.80%, 25.85%, 25.90%, 25.95%, 26.00%, 26.05%, 26.10%, and 26.15%. , 26.20%, 26.25%, 26.30%, 26.35%, 26.40%, 26.45%, 25.62%, 25.82%, 25.69%, 25.36%, 25.77%, 25.87%, 25.79%, 26.03%, 25.74%, 26.52%, 25.91%, or 25.73%, or any value within a range formed with any two of the above specific values ​​as endpoints, as long as crystallized glass or chemically strengthened crystallized glass with the performance required for this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as crystallized glass or chemically strengthened crystallized glass with the performance required for this application can be obtained.

[0133] Both Na2O and Li2O are alkali metal oxides, and their common characteristics include the ability to break Si-O bonds in glass, disrupt the glass network, and lower the high-temperature viscosity of glass. However, if added in excessive amounts, the weather resistance of the glass is greatly impaired. When multiple types of alkali metal oxides are added to the glass composition, a complex "cooperative effect" occurs, and the performance of the glass does not change linearly with the addition of a single alkali metal. This phenomenon, where the performance of glass does not change linearly when multiple types of alkali metal oxides are added to glass, is called the "mixed alkali effect." For example, when adding a mixture of several alkali metal oxides to the glass composition, the improvement in weather resistance is more advantageous than that achieved by adding a single alkali metal oxide. However, there are limits, and it is difficult to achieve the desired effect if the amount is too much or too little.

[0134] In this application, in addition to adjusting and controlling the content range of each oxide component, by adjusting and controlling the blending ratio relationship between each oxide component, and in particular by adjusting and controlling the mole fraction relationship between Na2O, B2O3, ZrO2, or Li2O, it is possible to obtain a crystallized glass that satisfies the desired crystalline phase structure, and also contribute to the crystallized glass obtaining excellent optical performance and high intrinsic strength.

[0135] In some embodiments of this application, in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, the mole fractions of Na2O [Na2O], B2O3 [B2O3], and ZrO2 [ZrO2] are: Z = -1.344 × (2.65 - 100 × [Na2O]) 2 The expression +0.466×100×[B2O3]+1.203×100×[ZrO2] satisfies 4.80≦Z≦5.35, and preferably 5.05≦Z≦5.25.

[0136] In some embodiments, the value of Z in the mole fraction relation between Na2O, B2O3, and ZrO2 in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, is 4.80, 4.85, 4.90, 4.95, 4.98, 5.05, 5.06, 5.07, 5.08, 5.09, 5.10, 5.11, 5.12, 5.13, 5.14, 5.15, 5.16, 5.17, 5.18, 5.19, 5.35, 5.30, or 5.20, or a value within a range formed with any two of the above specific values ​​as endpoints, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other ranges, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0137] In some embodiments of this application, in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, the mole fraction of Na2O [Na2O] and the mole fraction of B2O3 [B2O3] satisfy the relationship 0.90% ≤ [Na2O] - [B2O3] ≤ 3.10%, preferably [Na2O] - [B2O3] satisfies 2.00% ≤ [Na2O] - [B2O3] ≤ 3.00%, and more preferably 2.30% ≤ [Na2O] - [B2O3] ≤ 3.00%.

[0138] In some embodiments, in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, the difference in mole fractions of Na2O and B2O3, [Na2O]-[B2O3], is 0.90%, 1.00%, 1.20%, 1.25%, 1.26%, 1.35%, 1.45%, 1.55%, 1.65%, 1.75%, 1.85%, 1.95%, 2.00%, 2.0%. The values ​​may be 5%, 2.15%, 2.25%, 2.35%, 2.45%, 2.50%, 2.55%, 2.65%, 2.75%, 2.85%, 2.95%, 3.10%, 1.79%, 0.96%, 2.36%, 2.96%, 3.01%, 2.93%, 3.00%, or 3.02%, or any of the above values ​​may be within a range formed with any two specific values ​​as endpoints, as long as crystallized glass or chemically strengthened crystallized glass with the performance required for this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as crystallized glass or chemically strengthened crystallized glass with the performance required for this application can be obtained.

[0139] In some embodiments of this application, in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, the mole fraction of Na2O [Na2O] and the mole fraction of Li2O [Li2O] satisfy the relationship 8.55 ≤ [Li2O] / [Na2O] ≤ 13.85, and preferably, [Li2O] / [Na2O] satisfies 8.60 ≤ [Li2O] / [Na2O] ≤ 11.00.

[0140] In some embodiments, the ratio of the mole fractions of Li2O to Na2O [Li2O] / [Na2O] in the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass, may be 8.55, 9.00, 9.50, 10.00, 10.50, 10.55, 11.00, 11.50, 12.00, 12.50, 13.00, 13.50, 13.83, 10.93, 13.01, 10.92, 8.73, 8.61, 8.79, 8.83, 8.84, 8.69, or 13.85, or may be a value within a range formed with any two of the above specific values ​​as endpoints, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other ranges, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0141] In some embodiments of this application, the composition of the central region or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass may further contain other components while satisfying the above composition range, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. For example, in some embodiments, the composition of the central region or tensile stress layer of the chemically strengthened crystallized glass, or the composition of the crystallized glass for preparing the chemically strengthened crystallized glass, or the composition of the base glass may further contain CaO: 0.00 mol% to 1.00 mol% and K2O: 0.00 mol% to 1.00 mol%, expressed as the mole fraction of oxides.

[0142] In this application, after chemical strengthening treatment to form chemically strengthened crystallized glass, the crystal phase structure of the crystallized glass does not change significantly; that is, the crystallized glass is the same as or nearly the same as the chemically strengthened crystallized glass prepared thereby in terms of crystallinity, average grain size, and optical properties. For example, refer to the comparison shown in Figures 2 and 3. Similarly, the stress structure generated during the chemical strengthening process can appropriately improve the mechanical properties of the glass product. In this application, after chemical strengthening treatment to form chemically strengthened crystallized glass, the mechanical properties such as Young's modulus and Vickers hardness do not decrease; that is, if the Young's modulus of the crystallized glass is greater than 100 GPa, the Young's modulus of the chemically strengthened crystallized glass prepared thereby is also greater than 100 GPa.

[0143] In this application, the expression "the lithium disilicate crystalline phase has a larger mass fraction than other crystalline phases present in the chemically strengthened crystallized glass" or "the lithium disilicate is the main crystalline phase" or other similar expressions means that the lithium disilicate crystalline phase accounts for more than 70% of the mass fraction of all crystalline phases in the crystallized glass or chemically strengthened crystallized glass according to the embodiments of this application. In some embodiments, the mass of the lithium disilicate crystalline phase accounts for 70% or more of all crystalline phases in the crystallized glass or the chemically strengthened crystallized glass used to prepare the chemically strengthened crystallized glass, and preferably, the mass of the lithium disilicate crystalline phase accounts for 85% or more of all crystalline phases in the crystallized glass or the chemically strengthened crystallized glass used to prepare the chemically strengthened crystallized glass. Exemplary, for crystallized glass or chemically strengthened crystallized glass to be prepared, the mass ratio (also referred to as weight ratio) of the lithium disilicate crystalline phase to all crystalline phases may be 70%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 96%, 97%, 98%, 100%, or 95%, or any value within a range formed with any two of the above specific values ​​as endpoints, as long as crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0144] In some embodiments of this application, the degree of crystallinity of the crystallized glass or chemically strengthened crystallized glass is 45% or higher, preferably 45% to 85%, and more preferably 55% to 65%. A higher degree of crystallinity of the crystallized glass or chemically strengthened crystallized glass is advantageous in obtaining high impact resistance and high intrinsic strength. However, if the degree of crystallinity is too high, it impairs the chemical strengthening effect of the crystallized glass, increasing the chemical strengthening time required to obtain chemically strengthened crystallized glass with a high stress level, and impairing the optical performance of the crystallized glass. In this application, by satisfying the desired degree of crystallinity of the crystallized glass, the crystallized glass can have relatively good impact resistance and high intrinsic strength, while also ensuring excellent optical performance and contributing to the improvement of the chemical strengthening effect.

[0145] In some embodiments of this application, the degree of crystallinity of the crystallized glass or chemically strengthened crystallized glass may be 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85%, or within a range defined by any two of the above specific values ​​as endpoints, as long as the crystallized glass or chemically strengthened crystallized glass having the performance required of this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as the crystallized glass or chemically strengthened crystallized glass having the performance required of this application can be obtained.

[0146] In some embodiments of this application, other possible crystalline phases in crystallized glass or chemically strengthened crystallized glass include, in non-limiting examples, lithium phosphate crystalline phase. In some embodiments, preferably, the crystallized glass or chemically strengthened crystallized glass does not contain petalite crystalline phase. Here, “does not contain petalite crystalline phase” means that the petalite crystalline phase content is 0 or less. By controlling the precipitation of other crystalline phases, lithium disilicate can contribute to forming a desired structure, thereby ensuring high mechanical strength, excellent optical properties, and excellent break resistance of the crystallized glass or chemically strengthened crystallized glass.

[0147] In some embodiments of this application, the average grain size of crystallized glass or chemically strengthened crystallized glass is 40 nm or less, preferably 15 to 35 nm. Appropriate average grain size contributes to the crystallized glass having excellent optical performance and high intrinsic strength. If the average grain size is too large, the crystallized glass is prone to devitrification, and the chemical strengthening effect is impaired. In this application, by satisfying appropriate average grain size, the crystallized glass can have relatively good impact resistance and high intrinsic strength, while ensuring excellent optical performance and contributing to improved chemical strengthening effect.

[0148] In some embodiments, the average grain size of the crystallized glass or chemically strengthened crystallized glass may be 40 nm, 35 nm, 30 nm, 25 nm, 20 nm, 15 nm, or 10 nm, or a range formed with any two of the above specific values ​​as endpoints, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0149] In some embodiments of this application, crystallized glass or chemically strengthened crystallized glass is transparent within the visible light wavelength range, and preferably, with a thickness of 0.70 mm, the transmittance of the crystallized glass or chemically strengthened crystallized glass for light with a wavelength of 550 nm is 90.00% or more, preferably more than 90.40%. Chemically strengthened crystallized glass that satisfies this transmittance can ensure relatively good light transmission, has a relatively good transparency effect, and is suitable for displays that require a display effect. Here, "visible light wavelength range" refers to light with a wavelength of 360 nm to 740 nm.

[0150] In some embodiments, for a thickness of 0.70 mm, the transmittance of the crystallized glass or chemically strengthened crystallized glass for a wavelength of 550 nm is 90.00%, 90.10%, 90.20%, 90.31%, 90.40%, 90.50%, 91.00%, 90.52%, 90.70%, 90.62%, 90.85%, 90.70%, 90.63%, 90.51%, or 92.00%, or a value within a range configured with any two of the above specific values ​​as endpoints, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other range, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0151] In some embodiments of this application, the haze of the crystallized glass or chemically strengthened crystallized glass is less than 0.30% when the thickness is 0.70 mm. Haze represents the cloudy or opaque appearance of the interior or surface of the crystallized glass or chemically strengthened crystallized glass due to the diffuse reflection of light, and the smaller the haze, the better the transparency and display effect of the crystallized glass or chemically strengthened crystallized glass. In some embodiments, when the thickness is 0.70 mm, the haze of the crystallized glass or chemically strengthened crystallized glass may be 0.25%, 0.20%, 0.15%, 0.10%, 0.05%, 0.21%, 0.14%, 0.13%, 0.15%, 0.16%, or 0.29%, or may be a value within a range configured with any two of the above specific values ​​as endpoints, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required of this application can be obtained. In specific embodiments, any of the above ranges can be combined with any other ranges, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0152] In some embodiments of this application, for a thickness of 0.70 mm, the b-value of the crystallized glass or chemically strengthened crystallized glass is less than 0.70, preferably 0.60 or less. In this application, the b-value is the optical b-value measured with a D65 light source. In this application, the b-value is measured in transmittance mode using a Konica Minolta CM-3600A, and the result is displayed as b(D65). A smaller b-value ensures a relatively good display effect for the crystallized glass or chemically strengthened crystallized glass, while a b-value that is too large results in undesirable colors appearing in the crystallized glass or chemically strengthened crystallized glass, and as a result, the display effect cannot meet the application requirements of the display cover glass.

[0153] In some embodiments, for a thickness of 0.70 mm, the b-value of the crystallized glass or chemically strengthened crystallized glass may be 0.69, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.48, 0.47, 0.52, 0.51, 0.54, or 0.20, or a value within a range formed with any two of the above specific values ​​as endpoints, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0154] The crystallized glass or chemically strengthened crystallized glass according to this application has relatively high transmittance, relatively low haze, and a relatively low b-value. In other words, the crystallized glass or chemically strengthened crystallized glass according to this application has relatively excellent optical performance, good uniformity, and is transparent, and can meet the application requirements for cover glass for electronic device displays.

[0155] In some embodiments of this application, the Young's modulus of the crystallized glass or chemically strengthened crystallized glass is 100 GPa or more, preferably 105 GPa to 112.50 GPa. In this application, by setting the Young's modulus of the crystallized glass or chemically strengthened crystallized glass to 100 GPa or more, it is possible to ensure high network structure strength of the crystallized glass or chemically strengthened crystallized glass, reduce the stress relaxation effect that occurs in ion exchange in chemically strengthened crystallized glass, and mitigate the weakening effect on deep stress in composite compressive stress caused by high temperature, long duration, etc., in ion exchange.

[0156] In some embodiments, the Young's modulus of the crystallized glass or chemically strengthened crystallized glass may be 100 GPa, 105 GPa, 110 GPa, 106.32 GPa, 111.12 GPa, 110.82 GPa, 111.32 GPa, 111.09 GPa, 112.10 GPa, 111.51 GPa, or 112.50 GPa, or any value within a range formed with any two of the above specific values ​​as endpoints, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as the crystallized glass or chemically strengthened crystallized glass with the performance required in this application can be obtained.

[0157] In some embodiments of this application, the Vickers hardness of crystallized glass or chemically strengthened crystallized glass is 650 kgf / mm². 2 The above, preferably 650 kgf / mm² 2 ~800 kgf / mm 2 Therefore, if the Vickers hardness of crystallized glass or chemically strengthened crystallized glass falls within the above range, then the crystallized glass or chemically strengthened crystallized glass will have high hardness and high intrinsic strength, and excellent mechanical properties can be guaranteed.

[0158] In some embodiments of this application, the Vickers hardness of crystallized glass or chemically strengthened crystallized glass is 650 kgf / mm².2 , 654 kgf / mm 2 , 653 kgf / mm 2 658 kgf / mm 2 659 kgf / mm 2 or 660 kgf / mm 2 The range may be any of the above two specific values ​​as endpoints, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required for this application can be obtained. In specific embodiments, any of the above ranges may be combined with any other range, as long as a crystallized glass or chemically strengthened crystallized glass with the performance required for this application can be obtained.

[0159] In some embodiments of this application, a high-temperature, high-humidity aging test is performed on chemically strengthened crystallized glass under conditions of a temperature of 85°C and a relative humidity of 85%, wherein the high-temperature, high-humidity aging time is 240 hours or more. The high-temperature, high-humidity aging time is the total time from the start of the high-temperature, high-humidity test on the chemically strengthened crystallized glass until spots or cloudy marks that cannot be removed by wiping appear on the chemically strengthened crystallized glass.

[0160] Those skilled in the art will select the thickness of crystallized glass or chemically strengthened crystallized glass according to their needs. In some embodiments of this application, the thickness of the crystallized glass or chemically strengthened crystallized glass is 0.3 mm to 2 mm, preferably 0.45 mm to 0.8 mm. Exemplarily, the thickness of the crystallized glass or chemically strengthened crystallized glass is 0.3 mm to 1.5 mm, 0.3 mm to 1.00 mm, or 0.40 mm to 0.80 mm. In specific embodiments, any of the above ranges can be combined with any other range, as long as a chemically strengthened crystallized glass with the required performance of this application can be obtained.

[0161] In some embodiments of this application, the crystallized glass or chemically strengthened crystallized glass is planar or curved.

[0162] The above describes the composition, crystalline phase structure, and stress structure of chemically strengthened crystallized glass. The following describes in detail the preparation method for chemically strengthened crystallized glass.

[0163] In this application, the preparation process for chemically strengthened crystallized glass mainly includes the preparation process for crystallized glass and the chemical strengthening process, and the preparation process for crystallized glass mainly includes the preparation process for the base glass and the heat treatment process for the base glass.

[0164] In this application, the base glass is prepared by a molding method in the prior art, but is not limited thereto. For example, the molding method for the base glass includes, but is not limited to, the float method, the overflow method, the rolling or casting process. Exemplarily, the base glass can be obtained by uniformly mixing each component according to the formulation, melt-molding, and then cooling and tempering.

[0165] For example, each raw material (common industrial material) is prepared according to the mixing ratio, a clarifying agent is added, and after mixing for a certain period of time, a uniformly mixed raw material mixture is obtained. The raw material mixture is placed in a platinum crucible and heated to 1250°C to 1680°C, preferably with a melting temperature of 1480°C to 1680°C, preferably kept at this temperature for 3 to 12 hours, then poured into a molding die and cooled and molded, preferably cooled to 750°C to 1000°C, and then placed in a tempering furnace for tempering treatment, preferably with a tempering temperature of 400°C to 650°C, preferably for a tempering time of 10 to 48 hours. Then, it is furnace-cooled to room temperature to obtain the base glass. A person skilled in the art can select the type and amount of clarifying agent according to their needs, and does not need to use inventive ability. Furthermore, the clarifying agent is one or more of the following: sodium chloride, tin oxide, antimony oxide, or arsenic oxide, and the amount of clarifying agent added is 0 wt% to 1 wt% of the total amount of each raw material.

[0166] In some embodiments of this application, the heat treatment process of the base glass includes a nucleation treatment and / or a crystallization treatment, preferably using both a nucleation treatment and a crystallization treatment. In some embodiments, the crystallization treatment includes a one-stage crystallization treatment or a two-stage crystallization treatment. In some embodiments, the preparation of curved crystallized glass uses a two-stage crystallization treatment. When using a two-stage crystallization treatment, the second stage crystallization treatment involves placing the crystallized glass material obtained from the first stage crystallization treatment into a heat bending mold and heating it to the crystallization temperature to perform a 3D heat bending molding treatment.

[0167] In some embodiments of this application, when heat treatment is performed on a substrate glass to obtain desired physical properties of crystallized glass, a single-stage heat treatment may be performed, or a two-stage or multi-stage heat treatment may be performed. In the case of a single-stage heat treatment, it can be understood that a single-stage heating is performed directly without a separate nucleation treatment, and the crystallization treatment is performed at the temperature conditions where nucleation and target crystal growth have reached the first-stage heating process. In the case of a two-stage heat treatment, two stages of heating are performed, first the nucleation treatment is performed, and then the target crystal growth treatment, i.e., the crystallization treatment is performed.

[0168] In some embodiments, in order to precipitate a desired crystalline phase in the crystallized glass and obtain the desired physical properties, the nucleation treatment temperature may be 530 to 600°C, the nucleation treatment time may be 0 to 24 hours, preferably 2 to 8 hours. The crystallization treatment temperature may be 700 to 750°C, the crystallization treatment time may be 0.10 to 24 hours, preferably 1 to 3 hours. When performing heat treatment, the heating rate is preferably 5 to 15°C / min, more preferably 10°C / min. The nucleation treatment temperature is a temperature at which crystal nuclei can be formed. The crystallization treatment temperature is a temperature suitable for the controllable growth of the target crystal.

[0169] After heat treatment, to obtain crystallized glass samples that meet the required standards or requirements, those skilled in the art may perform other general processes, such as shaping, cutting (e.g., cutting using a multi-wire cutting machine), CNC machining (i.e., computer numerical control), slimming, or polishing.

[0170] In some embodiments of this application, chemically strengthened crystallized glass that satisfies desired performance can be prepared by subjecting the above-mentioned crystallized glass to a specific chemical strengthening treatment.

[0171] In this application, the chemical strengthening treatment, i.e., the ion exchange method, involves immersing crystallized glass in a molten salt bath and exchanging alkali metal ions with relatively small ionic radii in the crystallized glass with alkali metal ions with relatively large ionic radii in the molten salt bath. This forms a compressive stress layer on the surface of the crystallized glass, thereby obtaining chemically strengthened crystallized glass with superior mechanical properties.

[0172] In some embodiments of this application, the chemical strengthening treatment may be a one-step or multi-step strengthening method. The molten salt bath for chemical strengthening is a molten salt bath containing a sodium salt and / or a potassium salt. Preferably, the molten salt bath for chemical strengthening according to this application is a mixed molten salt bath containing a sodium salt and a potassium salt, and preferably the temperature of the molten salt bath is 380°C to 500°C, more preferably 380°C to 470°C. In some embodiments of this application, preferably, in the salt bath, the concentration of the potassium salt is 0 wt% to 90 wt%, the concentration of the sodium salt is 10 wt% to 100 wt%, and more preferably, a predetermined amount (e.g., 0 wt% to 0.5 wt%) of lithium salt is added to the salt bath. In some embodiments of this application, preferably, in the salt bath, the concentration of potassium salt is 20 wt% to 90 wt%, the concentration of sodium salt is 10 wt% to 80 wt%, and more preferably, 0.1 wt% to 0.5 wt% of lithium salt is added to the salt bath. In some embodiments of this application, preferably, the chemical strengthening treatment time is 0.1 hours to 6 hours, and more preferably, 0.1 hours to 3 hours. The sodium salt is at least one selected from sodium nitrate, sodium sulfate, and sodium carbonate, and is preferably sodium nitrate. The potassium salt is at least one selected from potassium nitrate, potassium sulfate, and potassium carbonate, and is preferably potassium nitrate. The lithium salt is at least one selected from lithium nitrate, lithium sulfate, and lithium carbonate, and is preferably lithium nitrate.

[0173] The crystallized glass or chemically strengthened crystallized glass relating to this application may be used in electronic devices, including, but not limited to, mobile phones, tablets, portable game consoles, portable digital devices (e.g., digital cameras), in-car infotainment systems, electronic whiteboard glass, smart homes, and smart wearables (e.g., smart bands, smart watches, smart glasses). The crystallized glass or chemically strengthened crystallized glass relating to this application may also be used in vehicles, aircraft, or spacecraft, and in any glass device that uses crystallized glass, for example, in displays, cover glass, touch panels, glass interior screens, or inner frames of electronic devices, for example, in windshields or side windows of vehicles, aircraft, or spacecraft, for example, work surfaces, other surfaces, electrical appliance doors, floor tiles, wall panels, or storage containers. Other surfaces include, but are not limited to, exterior wall surfaces, stair surfaces, column decorative panels, or counter surfaces. Storage containers include, but are not limited to, cups, plates, medicine bottles, or beverage bottles.

[0174] Exemplary, the superior performance crystallized glass or chemically strengthened crystallized glass relating to this application can be used to manufacture glass devices. These glass devices may be regular or irregular in shape and can be manufactured as needed by those skilled in the art.

[0175] Exemplary, the superior performance crystallized glass or chemically strengthened crystallized glass relating to this application is used to manufacture cover glass. The cover glass is a display cover, back cover, or camera protective cover for an electronic device. Exemplary, the superior performance crystallized glass or chemically strengthened crystallized glass relating to this application can be used in electronic devices. As shown in Figures 4, 5, and 6, several embodiments of this application provide an electronic device. The electronic device may be a mobile phone, a tablet, a smart wearable device, or other electronic product. The electronic device includes a housing 1 assembled on the outside of the electronic device. The housing 1 includes a display cover 11 assembled on the front side and a back cover 12 assembled on the rear side, with the display cover 11 covering a display unit 4. The display cover 11 and / or the back cover 12 are made of the above-mentioned crystallized glass or chemically strengthened crystallized glass. In this application, the display cover 11 and the back cover 12 may be entirely made of the above-mentioned crystallized glass or chemically strengthened crystallized glass, or only partially made of the above-mentioned crystallized glass or chemically strengthened crystallized glass. In this application, the display may be a touch display, and the display cover 11 may be a protective cover installed on the touch display. In this application, the back cover 12 may cover only the back side of the electronic device (the side facing the display), or it may cover both the back side and the side frame of the electronic device, and optionally the back cover 12 may cover all the side frames around the electronic device, or it may cover only some of the side frames.

[0176] In some embodiments of this application, as shown in Figure 5, the electronic device further includes a camera assembly 2 located inside a housing 1. The housing 1 includes a camera protection cover 13, which covers the camera assembly 2 to protect it. The camera protection cover 13 can be made of the above-mentioned crystallized glass or chemically strengthened crystallized glass. In this application, the camera protection cover 13 may be made of only a portion of the above-mentioned crystallized glass or chemically strengthened crystallized glass, or it may be made of the above-mentioned crystallized glass or chemically strengthened crystallized glass in its entirety. In this application, the installation position of the camera protection cover 13 is determined according to the installation position of the camera assembly 2, and may be located on the front side of the electronic device or on the rear side of the electronic device. In some embodiments of this application, the camera protection cover 13 is a separate structure from the display cover 11 or the rear cover 12. In other embodiments of this application, the camera protection cover 13 is a structure formed integrally with the display cover 11 or the rear cover 12.

[0177] In some embodiments of this application, as shown in Figure 6, the electronic device includes an intermediate frame 3 located between the display unit 4 and the housing 1, wherein the intermediate frame 3 includes the crystallized glass or chemically strengthened crystallized glass described above.

[0178] In the embodiments of this application, any one of the display cover, back cover, camera protective cover, and intermediate frame in the electronic device may use the above-mentioned crystallized glass or chemically strengthened crystallized glass; any two may use the above-mentioned crystallized glass or chemically strengthened crystallized glass; any three may use the above-mentioned crystallized glass or chemically strengthened crystallized glass; or all may use the above-mentioned crystallized glass or chemically strengthened crystallized glass.

[0179] The technical proposal of this application will be described in more detail below using examples. The examples of this application described below are illustrative and are for interpretation purposes only, and are not intended to limit this application.

[0180] Example 1 (1) Preparation of the base glass: Each raw material (common industrial material) was prepared according to the component ratios shown in Table 1, with a total mass of 1000g of the prepared raw materials. 5g of sodium chloride (NaCl) as a clarifying agent was added to the prepared raw materials, and the mixture was mixed for 30 minutes using a V-type mixer to obtain a uniformly mixed raw material mixture.

[0181] The raw material mixture was transferred to a platinum crucible, melted in a platinum crucible at 1650°C for 5 hours, then molded in a molding die, cooled to 900°C, then tempered in a tempering furnace at 500°C for 24 hours, and finally cooled to room temperature to obtain a base glass block.

[0182] (2) Preparation of crystallized glass: Following the heat treatment process in Table 2, the base glass block was placed in a tempering furnace and heated from room temperature to 550°C at a heating rate of 10°C / min to perform nucleation treatment. After holding the temperature at this temperature for 4 hours, the temperature was heated to 710°C at a heating rate of 10°C / min to perform crystallization treatment. After holding the temperature at this temperature for 1.5 hours, the temperature was cooled to room temperature at a cooling rate of 1°C / min to obtain a crystallized glass block sample. Expressed as the mole fraction of oxides, the composition of the prepared crystallized glass was the same as that of the base glass. Details are shown in Table 1.

[0183] The obtained crystallized glass block samples were sequentially subjected to cold working treatments including cutting, CNC machining (model number of the CNC machine used in this application: RCG500S), and polishing, to obtain crystallized glass samples that met the required specifications and requirements. In Examples 1 to 7 and Comparative Examples 1 to 6 of this application, the above cold working treatments were performed on the crystallized glass block samples to obtain crystallized glass samples with a thickness of 0.70 mm, specifically, crystallized glass polished sheet samples of 50 mm × 50 mm × 0.70 mm or 157.79 mm × 73.82 mm × 0.70 mm.

[0184] Measurements were performed on the crystallized glass sample obtained in Example 1, and the results were as follows.

[0185] The composition of the crystalline phase, degree of crystallinity, average grain size, Vickers hardness, and Young's modulus of the crystallized glass sample were measured, as well as the optical b-value, haze, and transmittance (using light at a wavelength of 550 nm) of a 0.70 mm thick crystallized glass sample. The measurement results are shown in Table 2.

[0186] (3) Preparation of chemically strengthened crystallized glass: Following the chemical strengthening process in Table 3, the obtained crystallized glass sample was placed in the strengthening furnace chamber and preheated for 5 minutes. After preheating, it was quickly placed in a molten salt bath at 460°C to perform chemical strengthening. The composition of the molten salt was 90 wt% KNO3 + 10 wt% NaNO3 + 0.15 wt% LiNO3, where "0.15 wt% LiNO3" refers to the addition of 0.15 wt% LiNO3 based on the total mass of KNO3 and NaNO3, and other similar descriptions have similar meanings. After performing the chemical strengthening treatment for 3 hours, the crystallized glass sample was removed and placed in the furnace body of the strengthening furnace to cool slowly to room temperature. The salt adhering to the surface of the crystallized glass was washed off with clean water, and the crystallized glass sample was dried to obtain chemically strengthened crystallized glass.

[0187] Measurements were performed on the chemically strengthened crystallized glass obtained in Example 1, and the results were as follows.

[0188] I. For chemically strengthened crystallized glass, DOL_0, CS_50, and |CT_AV| were measured using an SLP-2000 stress meter (wavelength of light source used: 518 nm, SOC = 26 (nm / cm) / MPa, refractive index: 1.56, exposure time: 300 μsec), and the tensile stress linear density (CT_LD) value was calculated. The results are shown in Table 3.

[0189] II. XRF measurements were used to determine the mass fraction of Na2O and K2O on the surface of the chemically strengthened crystallized glass, and the results are shown in Table 3. Furthermore, the values ​​of N and Y were calculated.

[0190] III. The average sandpaper drop height resistance of chemically strengthened crystallized glass was tested, and high temperature and high humidity tests were performed on the chemically strengthened crystallized glass. The results are shown in Table 3.

[0191] Examples 2 to 7 Each example was carried out with reference to Example 1, and the differences, including the raw material composition, process parameters, and corresponding measurement results for each example, are shown in Tables 1 to 3.

[0192] Figure 1 shows the XRD pattern of the crystallized glass according to Example 1. As can be seen from the figure, the main crystalline phase in the crystallized glass is the lithium disilicate crystalline phase.

[0193] Figure 2 shows a comparative graph of the transmittance curves of crystallized glass and chemically strengthened crystallized glass according to Example 1. As can be seen from the graph, both the crystallized glass and the chemically strengthened crystallized glass prepared therefrom were transparent within the visible light range, had high transmittance, and showed almost no change in transmittance before and after chemical strengthening.

[0194] Figure 3 shows a comparative graph of the XRD patterns of crystallized glass and chemically strengthened crystallized glass according to Example 1. As can be seen from the graph, there was no significant change in the crystalline phase structure of the crystallized glass before and after the chemical strengthening treatment, and the main crystalline phase of the chemically strengthened crystallized glass prepared using the crystallized glass was also the lithium disilicate crystalline phase.

[0195] Comparative Examples 1 to 6 Each procedure was carried out with reference to Example 1, and the differences, including the raw material composition, process parameters, and corresponding measurement results for each comparative example, are shown in Tables 1 to 3.

[0196] Actual photographs of the chemically strengthened crystallized glass before and after high-temperature and high-humidity tests in Examples 1-3 and Comparative Examples 1-2 are shown in Figures 7-11, respectively. To show the state of the chemically strengthened crystallized glass sheet, it was photographed placed on paper with a black background. As can be seen from the comparison of the actual comparative photographs, this application demonstrates that by satisfying specific relational requirements for the mass fraction of Na2O, the mass fraction of K2O, and CT_LD on the surface of the chemically strengthened crystallized glass, the chemically strengthened crystallized glass can satisfy high stress levels, ensure relatively excellent high-temperature and high-humidity resistance, and exhibit superior weather resistance.

[0197] [Table 1] Note: The values ​​in Table 1 are obtained by substituting the molar percentage of the oxide content into each formula, and the mole unit does not play a role in the calculation of the formulas.

[0198] [Table 2]

[0199] [Table 3(1)] [Table 3(2)]

[0200] As can be seen from the examples and comparative examples in Tables 1 to 3 above, when the same crystallized glass is chemically strengthened, the resulting chemically strengthened crystallized glass satisfies the requirements of the N relation of this application. That is, the mass fraction of Na2O on the surface of the chemically strengthened crystallized glass, the mass fraction of K2O on the surface of the chemically strengthened crystallized glass, and CT_LD satisfy a specific relationship. This ensures that the chemically strengthened crystallized glass possesses both excellent stress levels and excellent high temperature and high humidity resistance. As a result, the resulting chemically strengthened crystallized glass has relatively high mechanical strength and good weather resistance.

[0201] In Comparative Examples 1 to 6, the mass fraction of Na2O on the surface of the chemically strengthened crystallized glass, the mass fraction of K2O on the surface of the chemically strengthened crystallized glass, and CT_LD did not satisfy a specific relationship. As a result, the prepared chemically strengthened crystallized glass developed spots or cloudy marks that could not be removed by wiping during high-temperature and high-humidity tests, clearly failing to meet application requirements in terms of weather resistance, or exhibiting relatively low stress levels and relatively poor resistance to drop damage.

[0202] The foregoing is merely a specific embodiment of the present application and does not limit it. Those skilled in the art may have various modifications and changes to this application. Any modifications, equivalent substitutions, or improvements made in the spirit and principles of this application fall within the scope of protection of this application.

[0203] Industrial applicability This application demonstrates that by ensuring that the surface composition and stress structure of chemically strengthened crystallized glass, in which lithium disilicate is the main crystalline phase, satisfy a specific relationship, it is possible to guarantee that chemically strengthened crystallized glass can achieve a high stress level and good weather resistance, thereby better ensuring that chemically strengthened crystallized glass can meet market application requirements. [Explanation of symbols]

[0204] 1 Housing 11 Display Cover 12 Back cover 13 Camera protective cover 2 Camera Assembly 3 Intermediate slot 4 Display Unit

Claims

1. Chemically strengthened crystallized glass, The chemically strengthened crystallized glass contains a lithium disilicate crystalline phase, the lithium disilicate crystalline phase has a larger mass fraction than other crystalline phases present in the chemically strengthened crystallized glass, the chemically strengthened crystallized glass has a compressive stress layer on its surface and tensile stress internally, and the chemically strengthened crystallized glass is N = n × (CT_LD - 50000) / 10000 satisfies -32.5 < N < 15, preferably -28.0 ≤ N ≤ 0, and more preferably -20.0 ≤ N ≤ -2.

5. Here, n = (Na on the surface of the chemically strengthened crystallized glass) ２ Mass fraction of O ÷ K on the surface of chemically strengthened crystallized glass ２ (mass fraction of O) ２ XRF measurement revealed that the Na on the surface of the chemically strengthened crystallized glass ２ The mass fraction of O and the K on the surface of chemically strengthened crystallized glass ２ The mass fraction of O is measured, CT_LD is the tensile stress linear density, with units of MPa / mm, and the calculation is performed by substituting the data according to the above unit requirements into the formula N = n × (CT_LD - 50000) / 10000 to obtain the calculation result, where the units themselves are not involved in the calculation. Chemically strengthened crystallized glass characterized by the following features.

2. The chemically strengthened crystallized glass satisfies 45,000 MPa / mm ≤ CT_LD ≤ 52,000 MPa / mm, preferably 45,900 MPa / mm ≤ CT_LD ≤ 50,000 MPa / mm, and more preferably 47,500 MPa / mm ≤ CT_LD ≤ 50,000 MPa / mm. The chemically strengthened crystallized glass according to feature 1.

3. The values ​​of N are -2.52, -4.07, -4.47, -4.75, -10.59, -11.90 or -12.73, and / or The values ​​of CT_LD are 47517.24 MPa / mm, 48185.39 MPa / mm, 49692.43 MPa / mm, 47636.26 MPa / mm, 47919.69 MPa / mm, 47679.19 MPa / mm, or 48097.14 MPa / mm. The chemically strengthened crystallized glass according to claim 1 or 2.

4. XRF measurement revealed that, expressed as the mass fraction of oxides, the Na content on the surface of the chemically strengthened crystallized glass was ２ The mass fraction of O is 5% to 8.5%, preferably 5.5% to 7.5%, and / or XRF measurement revealed that the K of the surface of the chemically strengthened crystallized glass, expressed as the mass fraction of oxides, ２ The mass fraction of O is 0.7% to 2.0%, preferably 0.7% to 1.5%, and / or When expressed as the mass fraction of the oxide, in the composition of the central portion or the tensile stress layer of the chemically strengthened crystallized glass, the mass fraction of Na ２ O is 3% to 3.5%, and preferably, the mass fraction of Na ２ O is 3.1% to 3.2% A chemically strengthened crystallized glass according to any one of claims 1 to 3.

5. XRF measurement revealed that, expressed as the mass fraction of oxides, the Na content on the surface of the chemically strengthened crystallized glass was ２ The mass fraction of O is 5.30%, 6.12%, 7.00%, 5.21%, 6.32%, 5.17%, or 6.36%, and / or XRF measurement revealed that the K of the surface of the chemically strengthened crystallized glass, expressed as the mass fraction of oxides, ２ The mass fraction of O is 1.25%, 0.81%, 0.77%, 1.24%, 0.80%, or 1.26%, and / or Expressed as a mass fraction of oxides, in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, Na ２ The mass fraction of O is 3.16% or 3.14%. A chemically strengthened crystallized glass according to any one of claims 1 to 4.

6. The aforementioned chemically strengthened crystallized glass is Y=ΔC×((CT_LD-50000) / 100) ２ However, Y < 60 is satisfied, preferably Y ≤ 50, more preferably Y ≤ 20, Here, ΔC is the Na on the surface of the chemically strengthened crystallized glass. ２ The mass fraction of O and the Na at the center of the chemically strengthened crystallized glass ２ This is the difference from the mass fraction of O, and XRF measurement reveals the Na on the surface of the chemically strengthened crystallized glass. ２ The mass fraction of O is measured, CT_LD is the tensile stress linear density, with units of MPa / mm, and the formula is Y = ΔC × ((CT_LD - 50000) / 100). ２ In this case, the data is substituted according to the above unit requirements and calculations are performed to obtain the calculation result, and the units themselves do not participate in the calculation. A chemically strengthened crystallized glass according to any one of claims 1 to 5.

7. The values ​​of Y are 0.36, 10.14, 11.58, 11.88, 13.02, 13.25, or 14.

84. A chemically strengthened crystallized glass according to any one of claims 1 to 6.

8. The aforementioned chemically strengthened crystallized glass is The following conditions must be met: 75 MPa ≤ |CT_AV| ≤ 120 MPa, preferably 77 MPa ≤ |CT_AV| ≤ 90 MPa, where |CT_AV| is the absolute value of the mean tensile stress, and / or DOL_0 is 0.18t to 0.25t, preferably 0.20t to 0.25t, where DOL_0 is the depth of the compressive stress layer, t is the thickness of the chemically strengthened crystallized glass, and / or CS_50 is 150 MPa to 250 MPa, preferably 160 MPa to 180 MPa, and CS_50 is the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened crystallized glass. A chemically strengthened crystallized glass according to any one of claims 1 to 7.

9. Expressed as the mole fraction of oxides, the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass is SiO ２ :61.50%~63.40%, Al ２ O ３ :2.75%~2.99%, P ２ O ５ :0.91% to 1.91%, ZrO ２ :4.20%~4.85%, Na ２ O: 1.80% to 3.20%, B ２ O ３ : 0-1.00% and Li ２ O: Includes 25.32% to 26.52% A chemically strengthened crystallized glass according to any one of claims 1 to 8.

10. Expressed as the mole fraction of oxides, in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, SiO ２ The mole fraction is 61.50% to 63.30%, preferably SiO ２ The mole fraction is 62.00% to 62.60%, and / or P ２ O ５ The mole fraction is 1.20% to 1.91%, preferably P ２ O ５ The mole fraction is 1.30% to 1.60%, and / or Na ２ The mole fraction of O is 1.85% to 3.05%, preferably Na ２ The mole fraction of O is 2.20% to 3.00%, and / or B ２ O ３ The mole fraction of is 0-0.65%, and / or ZrO ２ The mole fraction is 4.20% to 4.60%, and / or Li ２ The mole fraction of O is 25.52% to 26.52%, preferably Li ２ The mole fraction of O is between 25.52% and 26.00%. A chemically strengthened crystallized glass according to any one of claims 1 to 9.

11. Expressed as the mole fraction of oxides, in the composition of the central part or tensile stress layer of the chemically strengthened crystallized glass, SiO ２ The mole fractions are 63.26%, 62.35%, or 62.52%, and / or Al ２ O ３ The mole fractions are 2.87%, 2.94%, or 2.92%, and / or P ２ O ５ The mole fraction is 1.41% or 1.53%, and / or ZrO ２ The mole fraction is 4.33% or 4.34%, and / or Na ２ The mole fraction of O is 2.36%, 2.93%, or 2.96%, and / or Li ２ The mole fraction of O is 25.77%, 25.91%, or 25.73%. A chemically strengthened crystallized glass according to any one of claims 1 to 10.

12. In the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, Na ２ Mole fraction of O [Na ２ O], B ２ O ３ mole fraction [B ２ O ３ ] and ZrO ２ mole fraction [ZrO ２ ]teeth, Z=-1.344×(2.65-100×[Na ２ O]) ２ +0.466×100×[B ２ O ３ ]+1.203×100×[ZrO ２ The relationship ] is satisfied, and Z satisfies 4.80 ≤ Z ≤ 5.35, preferably 5.05 ≤ Z ≤ 5.25, and / or, In the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, Na ２ Mole fraction of O [Na ２ O] and B ２ O ３ mole fraction [B ２ O ３ ]teeth, 0.90% ≤ [Na ２ O] - [B] ２ O ３ [Na] ≤ 3.10%, preferably 2.00% ≤ [Na ２ O] - [B] ２ O ３ [Na] ≤ 3.00%, and more preferably 2.30% ≤ [Na] ２ O] - [B] ２ O ３ ] ≤ 3.00% and / or, In the composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass, Na ２ Mole fraction of O [Na ２ O] and Li ２ Mole fraction of O [Li ２ O] is, 8.55 ≤ [Li ２ O] / [Na ２ [O] ≤ 13.85, preferably 8.60 ≤ [Li ２ O] / [Na ２ Satisfying O ≤ 11.00 A chemically strengthened crystallized glass according to any one of claims 1 to 11.

13. The composition of the central portion or tensile stress layer of the chemically strengthened crystallized glass is: The value of Z is 5.10, 5.09, or 5.12, and / or [Na ２ O] - [B] ２ O ３ The value of ] is 2.36%, 2.93%, or 2.96%, and / or [Li ２ O] / [Na ２ The value of O is 10.92, 8.84, or 8.

69. The chemically strengthened crystallized glass according to feature 12.

14. The mass of the lithium disilicate crystalline phase accounts for 70% or more of all crystalline phases of the chemically strengthened crystallized glass. Preferably, the mass of the lithium disilicate crystalline phase accounts for 85% or more of all crystalline phases of the chemically strengthened crystallized glass. A chemically strengthened crystallized glass according to any one of claims 1 to 13.

15. The average grain size of the chemically strengthened crystallized glass is 40 nm or less, preferably 15 nm to 35 nm, and / or The degree of crystallinity of the chemically strengthened crystallized glass is 45% or more, preferably 45% to 85%, and more preferably 55% to 65%. A chemically strengthened crystallized glass according to any one of claims 1 to 14.

16. The chemically strengthened crystallized glass is transparent within the visible light wavelength range, preferably, when it has a thickness of 0.70 mm, the transmittance of the chemically strengthened crystallized glass at a wavelength of 550 nm is 90.00% or more, preferably, the transmittance is greater than 90.40%, and / or For a thickness of 0.70 mm, the haze of the chemically strengthened crystallized glass is less than 0.30%, preferably less than 0.20%, and / or When the thickness is 0.70 mm, the b value of the chemically strengthened crystallized glass is less than 0.70, preferably 0.60 or less. A chemically strengthened crystallized glass according to any one of claims 1 to 15.

17. The Young's modulus of the chemically strengthened crystallized glass is 100 GPa or more, preferably 105 GPa to 112.50 GPa, and / or The Vickers hardness of the chemically strengthened crystallized glass is 650 kgf / mm ２ or more, preferably 650 kgf / mm ２ to 800 kgf / mm ２ is A chemically strengthened crystallized glass according to any one of claims 1 to 16.

18. The chemically strengthened crystallized glass is planar or curved, and / or the thickness of the chemically strengthened crystallized glass is 0.3 mm to 2 mm, preferably 0.45 mm to 0.8 mm, and / or the chemically strengthened crystallized glass does not contain a petalite crystal phase. A chemically strengthened crystallized glass according to any one of claims 1 to 17.

19. A high-temperature, high-humidity aging test is performed on the chemically strengthened crystallized glass under conditions of 85°C and 85% relative humidity, and the high-temperature, high-humidity aging time is 240 hours or more, and the high-temperature, high-humidity aging time is the total time from the start of the high-temperature, high-humidity test on the chemically strengthened crystallized glass until spots or cloudy marks that cannot be removed by wiping appear on the chemically strengthened crystallized glass. A chemically strengthened crystallized glass according to any one of claims 1 to 18.

20. It is a cover glass, The cover glass is prepared from chemically strengthened crystallized glass as described in any one of claims 1 to 19, or the cover glass includes chemically strengthened crystallized glass as described in any one of claims 1 to 19. A cover glass characterized by the following features.

21. Includes a chemically strengthened crystallized glass according to any one of claims 1 to 19 An electronic device characterized by the following features.

22. The electronic device includes a housing assembled on the outside of the electronic device, and the housing includes chemically strengthened crystallized glass as described in any one of claims 1 to 19. The electronic device according to feature 21.

23. The housing includes a display cover assembled on the front side of the electronic device, and the display cover includes chemically strengthened crystallized glass as described in any one of claims 1 to 19. The electronic device according to claim 22.

24. The housing includes a rear cover assembled on the rear side of the electronic device, and the rear cover includes chemically strengthened crystallized glass as described in any one of claims 1 to 19. The electronic device according to claim 22 or 23, characterized in that it is an electronic device.

25. The electronic device further includes a camera assembly located inside the housing, the housing includes a camera protective cover, the camera protective cover covers the camera assembly and includes chemically strengthened crystallized glass as described in any one of claims 1 to 19. The electronic device according to any one of claims 22 to 24.

26. The electronic device further includes an intermediate frame, the intermediate frame includes a chemically strengthened crystallized glass as described in any one of claims 1 to 19. The electronic device according to any one of claims 22 to 25.

27. Includes a chemically strengthened crystallized glass according to any one of claims 1 to 19 A glass device characterized by the following features.

Images