Chemically strengthened microcrystalline glass, cover glass, electronic device, and glassware

Abstract

The application provides a chemically strengthened microcrystalline glass, a cover plate glass, an electronic device and a glass device, and belongs to the technical field of microcrystalline glass. The application makes the surface composition and stress structure of the chemically strengthened microcrystalline glass with lithium disilicate as the main crystal phase meet specific requirements, so that the chemically strengthened microcrystalline glass can meet high stress levels and also ensure good weather resistance, and can better ensure that the chemically strengthened microcrystalline glass meets application requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microcrystalline glass, in particular to a chemically strengthened microcrystalline glass, a cover glass, an electronic device and a glass device. BACKGROUND

[0002] Microcrystalline glass is a kind of solid composite material formed by controlled crystallization of base glass during heat treatment. Microcrystalline glass contains microcrystalline phase and glass phase. Compared with ordinary glass materials without microcrystalline phase, microcrystalline glass generally has higher strength, because the microcrystalline phase has higher strength than the glass phase, absorbs more energy when breaking, and can also extend the crack propagation path and hinder crack propagation, thus consuming more impact energy during the breaking and crushing process.

[0003] In recent years, microcrystalline glass has been gradually applied to various electronic devices, such as mobile phones, watches, tablets, notebook computers, e-book readers or other similar devices, as cover glass for electronic devices, such as display screen cover glass, electronic device back cover cover glass, etc. For the display screen of electronic devices, the cover glass is generally required to have good optical performance, as well as thin thickness, high mechanical performance, good environmental durability or weather resistance, etc.

[0004] In order to further improve the mechanical performance of microcrystalline glass, it is usually necessary to perform chemical strengthening treatment on the microcrystalline glass to make chemically strengthened microcrystalline glass with high stress level, high mechanical strength performance and high damage resistance performance through ion exchange.

[0005] For microcrystalline glass with main lithium disilicate crystal phase, the main process of chemical strengthening is usually sodium-lithium ion exchange, that is, during the chemical strengthening process, sodium ions in the chemical strengthening molten salt bath are ion exchanged with lithium ions in the microcrystalline glass. In order to obtain chemically strengthened microcrystalline glass with high mechanical performance, a certain amount of sodium ions is usually exchanged into the microcrystalline glass to realize high stress level by using the volume difference of exchanged ions, and then to improve the mechanical strength performance. If the content of exchanged sodium ions is small, the mechanical strength performance cannot be improved. SUMMARY

[0006] When the lithium disilicate-based glass-ceramics is subjected to sodium-lithium exchange during chemical strengthening, the deep compressive stress and the depth of the compressive stress layer of the glass-ceramics can be increased, but a sodium-rich layer is easily formed on the surface of the glass-ceramics after the exchange. When the exchange results in an increase in the sodium content on the surface of the chemically strengthened glass-ceramics, the mechanical properties of the glass-ceramics can be improved, but the high sodium content on the surface of the glass-ceramics can easily cause a decrease in the environmental durability or weather resistance of the chemically strengthened glass-ceramics. Generally, when the chemically strengthened glass-ceramics with a high sodium content on the surface is used for a long time in a sweat erosion environment or after being subjected to a humid environment, the smoothness of the surface of the glass-ceramics can easily decrease and become rough, and more seriously, the glass-ceramics can become foggy and form spots or white marks on the surface that cannot be wiped off. These conditions not only reduce the feeling of the user touching the screen, but also significantly reduce the screen display effect and appearance of the chemically strengthened glass-ceramics. Moreover, if the spots and fogging or whitening occur at the position of a camera, the camera effect of the mobile phone can be seriously affected.

[0007] The purpose of the present application is to provide a chemically strengthened glass-ceramics with a high stress level, which can ensure high mechanical strength and good environmental durability or weather resistance, by satisfying a specific relationship between the surface composition and stress of the lithium disilicate-based chemically strengthened glass-ceramics.

[0008] To achieve the above purpose, the present application provides the following technical solutions.

[0009] In a first aspect, a chemically strengthened glass-ceramics is provided, which contains a lithium disilicate crystal phase, wherein the lithium disilicate crystal phase has a larger mass percentage than other crystal phases present in the chemically strengthened glass-ceramics; the chemically strengthened glass-ceramics has a compressive stress layer on the surface and a tensile stress in the interior; and the chemically strengthened glass-ceramics satisfies:

[0010] N = n * (CT_LD-50000) / 10000, -32.5 < N < 15, preferably -28.0 < N < 0, more preferably -20.0 < N < -2.5,

[0011] wherein n = (mass percentage of Na2O on the surface of the chemically strengthened glass-ceramics / mass percentage of K2O on the surface of the chemically strengthened glass-ceramics) 2 The mass percentage of Na2O on the surface of the chemically strengthened glass-ceramics and the mass percentage of K2O on the surface of the chemically strengthened glass-ceramics are determined by XRF; CT_LD is the tensile stress linear density, with a unit of MPa / mm; in the formula N, the data are substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

[0012] The present application can ensure that the chemically strengthened microcrystalline glass meets the market application requirements by meeting the requirements of specific crystalline structure and formula N for the chemically strengthened microcrystalline glass, and ensuring that the chemically strengthened microcrystalline glass can achieve good weather resistance while meeting high stress levels.

[0013] As an optional embodiment, the chemically strengthened microcrystalline glass meets: 45000 MPa / mm≤CT_LD≤52000 MPa / mm, preferably, 45900 MPa / mm≤CT_LD≤50000 MPa / mm, more preferably, 47500 MPa / mm≤CT_LD≤50000 MPa / mm.

[0014] By making the chemically strengthened microcrystalline glass meet the appropriate stress structure, it is beneficial to obtain a chemically strengthened microcrystalline glass product with a higher stress level, and further beneficial to play the improvement effect of the stress structure on the mechanical strength performance, and ensure that the chemically strengthened microcrystalline glass meets excellent damage resistance.

[0015] As an optional embodiment, the value of formula N is -2.52, -4.07, -4.47, -4.75, -10.59, -11.90 or -12.73; and / or

[0016] 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.

[0017] As an optional embodiment, the surface Na2O content of the chemically strengthened microcrystalline glass is 5% to 8.5%, preferably 5.5% to 7.5%, in terms of mass percentage of oxides, as determined by XRF; and / or,

[0018] The surface K2O content of the chemically strengthened microcrystalline glass is 0.7% to 2.0%, preferably 0.7% to 1.5%, in terms of mass percentage of oxides, as determined by XRF; and / or,

[0019] The mass percentage of Na2O in the composition at the center of the chemically strengthened microcrystalline glass is 3% to 3.5%, preferably the mass percentage of Na2O is 3.1% to 3.2%, in terms of mass percentage of oxides.

[0020] As an optional embodiment, the surface Na2O mass percentage of the chemically strengthened glass-ceramics is 5.30%, 6.12%, 7.00%, 5.21%, 6.32%, 5.17% or 6.36% as measured by XRF in mass percentage of oxides; and / or,

[0021] The surface K2O mass percentage of the chemically strengthened glass-ceramics is 1.25%, 0.81%, 0.77%, 1.24%, 0.80% or 1.26% as measured by XRF in mass percentage of oxides; and / or,

[0022] The mass percentage of Na2O in the composition at the center of the chemically strengthened glass-ceramics is 3.16% or 3.14% in mass percentage of oxides.

[0023] As an optional embodiment, the chemically strengthened glass-ceramics satisfies:

[0024] Y = ΔC x ((CT_LD-50000) / 100) 2 Y < 60, preferably Y ≤ 50, more preferably Y ≤ 20,

[0025] wherein ΔC is the difference between the surface Na2O mass percentage of the chemically strengthened glass-ceramics and the mass percentage of Na2O at the center of the chemically strengthened glass-ceramics, the surface Na2O mass percentage of the chemically strengthened glass-ceramics being measured by XRF; CT_LD is the tensile stress linear density in MPa / mm, in formula Y, the data is substituted into the formula in the above unit and the calculation result is obtained, and the unit does not participate in the calculation.

[0026] By making the chemically strengthened glass-ceramics satisfy the specific crystalline structure and the requirement of formula Y, it is beneficial to make the chemically strengthened glass-ceramics achieve a high stress level.

[0027] As an optional embodiment, the value of formula Y is 0.36, 10.14, 11.58, 11.88, 13.02, 13.25 or 14.84.

[0028] As an optional embodiment, the chemically strengthened glass-ceramics satisfies:

[0029] 75 MPa ≤ |CT_AV| ≤ 120 MPa, preferably 77 MPa ≤ |CT_AV| ≤ 90 MPa, wherein |CT_AV| is the absolute value of the average tensile stress; and / or,

[0030] DOL_0 is 0.18t-0.25t, preferably 0.20t-0.25t, wherein DOL_0 is the depth of compressive stress layer, and t is the thickness of the chemically strengthened glass-ceramics; and / or

[0031] CS_50 is 150 MPa to 250 MPa, preferably 160 MPa to 180 MPa, wherein CS_50 refers to the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened glass-ceramic.

[0032] By making the chemically strengthened glass-ceramic satisfy a suitable stress structure, it is beneficial to obtain a chemically strengthened glass-ceramic product with a higher stress level, and further beneficial to exert the improvement effect of the stress structure on the mechanical strength performance, to ensure that the chemically strengthened glass-ceramic satisfies excellent damage resistance.

[0033] As an optional embodiment, the composition at the center of the chemically strengthened glass-ceramic, in terms of mole percentage of oxides, comprises: 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%.

[0034] By satisfying a specific glass composition, it is beneficial to obtain a glass-ceramic satisfying a specific crystal phase structure, and beneficial to obtain a chemically strengthened glass-ceramic satisfying a specific stress structure.

[0035] As an optional embodiment, in the composition at the center of the chemically strengthened glass-ceramic, in terms of mole percentage of oxides, comprises:

[0036] The mole percentage of SiO2 is 61.50% to 63.30%, preferably, the mole percentage of SiO2 is 62.00% to 62.60%; and / or,

[0037] The mole percentage of P2O5 is 1.20% to 1.91%, preferably, the mole percentage of P2O5 is 1.30% to 1.60%; and / or,

[0038] The mole percentage of Na2O is 1.85% to 3.05%, preferably, the mole percentage of Na2O is 2.20% to 3.00%; and / or,

[0039] The mole percentage of B2O3 is 0 to 0.65%; and / or, the mole percentage of ZrO2 is 4.20% to 4.60%; and / or,

[0040] The mole percentage of Li2O is 25.52% to 26.52%, preferably, the mole percentage of Li2O is 25.52% to 26.00%.

[0041] As an optional embodiment, in the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O], the molar percentage of B2O3 [B2O3] and the molar percentage of ZrO2 [ZrO2] satisfy the following relationship:

[0042] the molar percentage of SiO2 is 63.26%, 62.35% or 62.52%; and / or,

[0043] the molar percentage of Al2O3 is 2.87%, 2.94% or 2.92%; and / or,

[0044] the molar percentage of P2O5 is 1.41% or 1.53%; and / or,

[0045] the molar percentage of ZrO2 is 4.33% or 4.34%; and / or,

[0046] the molar percentage of Na2O is 2.36%, 2.93% or 2.96%; and / or,

[0047] the molar percentage of Li2O is 25.77%, 25.91% or 25.73%.

[0048] As an optional embodiment, in the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O], the molar percentage of B2O3 [B2O3] and the molar percentage of ZrO2 [ZrO2] satisfy the following relationship:

[0049] Z = -1.344 x (2.65 - 100 x [Na2O])2+ 0.466 x 100 x [B2O3] + 1.203 x 100 x [ZrO2], 4.80 ≤ Z ≤ 5.35,

[0050] preferably, 5.05 ≤ Z ≤ 5.25; and / or,

[0051] in the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of B2O3 [B2O3] satisfy the following relationship:

[0052] 0.90% ≤ [Na2O] - [B2O3] ≤ 3.10%, preferably, 2.00% ≤ [Na2O] - [B2O3] ≤ 3.00%, more preferably, 2.30% ≤ [Na2O] - [B2O3] ≤ 3.00%; and / or,

[0053] in the composition at the center of the chemically strengthened glass-ceramics, the molar percentage of Na2O [Na2O] and the molar percentage of Li2O [Li2O] satisfy the following relationship:

[0054] 8.55 < [Li2O] / [Na2O] < 13.85, preferably 8.60 < [Li2O] / [Na2O] < 11.00.

[0055] As an alternative embodiment, the composition at the center of the chemically strengthened glass-ceramic satisfies:

[0056] the value of formula Z is 5.10, 5.09 or 5.12; and / or,

[0057] the value of [Na2O] - [B2O3] is 2.36%, 2.93% or 2.96%; and / or,

[0058] the value of [Li2O] / [Na2O] is 10.92, 8.84 or 8.69.

[0059] As an alternative embodiment, the lithium disilicate crystalline phase has a mass fraction of more than 70% of all crystalline phases of the chemically strengthened glass-ceramic,

[0060] Preferably, the lithium disilicate crystalline phase has a mass fraction of more than 85% of all crystalline phases of the chemically strengthened glass-ceramic.

[0061] As an alternative embodiment, the chemically strengthened glass-ceramic has an average grain size of 40 nm or less, preferably an average grain size of 15 nm to 35 nm; and / or,

[0062] the chemically strengthened glass-ceramic has a crystallinity of more than 45%, preferably a crystallinity of 45% to 85%, more preferably a crystallinity of 55% to 65%.

[0063] As an alternative embodiment, the chemically strengthened glass-ceramic is transparent in the visible wavelength range, preferably has a transmittance of ≥ 90.00%, preferably > 90.40% for a 550 nm wavelength light at a thickness of 0.70 mm; and / or,

[0064] the chemically strengthened glass-ceramic has a haze of < 0.30%, preferably < 0.20%, at a thickness of 0.70 mm; and / or,

[0065] the chemically strengthened glass-ceramic has a b value of < 0.70, preferably ≤ 0.60, at a thickness of 0.70 mm.

[0066] As an alternative embodiment, the chemically strengthened glass-ceramic has a Young's modulus of ≥ 100 GPa, preferably a Young's modulus of 105 GPa to 112.50 GPa; and / or

[0067] the Vickers hardness of the chemically strengthened glass-ceramics is ≥ 650 kgf / mm 2 , preferably, the Vickers hardness of the chemically strengthened glass-ceramics is 650 kgf / mm 2 ~ 800 kgf / mm 2 .

[0068] As an optional embodiment, the chemically strengthened glass-ceramics is planar or curved; and / or, the thickness of the chemically strengthened glass-ceramics is 0.3 mm ~ 2 mm, preferably 0.45 mm ~ 0.8 mm; and / or, the chemically strengthened glass-ceramics does not contain a petalite crystal phase.

[0069] As an optional embodiment, the chemically strengthened glass-ceramics is subjected to high temperature and high humidity failure test at a temperature of 85°C and a relative humidity of 85%, and the high temperature and high humidity failure time of the chemically strengthened glass-ceramics is ≥ 240 h, wherein the high temperature and high humidity failure time is the total time from the beginning of the high temperature and high humidity test to the appearance of spots or whitening marks on the chemically strengthened glass-ceramics that cannot be wiped off.

[0070] In a second aspect, a cover glass is provided, which is made of the chemically strengthened glass-ceramics according to any one of the embodiments of the first aspect.

[0071] In a third aspect, an electronic device is provided, which comprises the chemically strengthened glass-ceramics according to any one of the embodiments of the first aspect.

[0072] As an optional embodiment, the electronic device comprises a housing assembled on the outer side of the electronic device, and the housing comprises the chemically strengthened glass-ceramics according to any one of the embodiments of the first aspect.

[0073] As an optional embodiment, the housing comprises a display screen cover plate assembled on the front side of the electronic device, and the display screen cover plate comprises the chemically strengthened glass-ceramics according to any one of the embodiments of the first aspect.

[0074] As an optional embodiment, the housing comprises a rear cover assembled on the rear side of the electronic device, and the rear cover comprises the chemically strengthened glass-ceramics according to any one of the embodiments of the first aspect.

[0075] As an optional embodiment, the electronic device further comprises a camera assembly located inside the housing, and the housing comprises a camera protection cover plate covering the camera assembly, and the camera protection cover plate comprises the chemically strengthened glass-ceramics according to any one of the embodiments of the first aspect.

[0076] As an optional embodiment, the electronic device further comprises a middle frame, and the middle frame comprises the chemically strengthened microcrystalline glass according to any one of the embodiments of the first aspect.

[0077] In some embodiments, the outer shell can be partially made of the chemically strengthened microcrystalline glass or entirely made of the chemically strengthened microcrystalline glass. The electronic device in the present application can be one or more of a display screen cover plate, a back cover, a camera protection cover plate, and a middle frame, which are made of the chemically strengthened microcrystalline glass according to any one of the embodiments of the first aspect.

[0078] In the fourth aspect, a glass device is provided, which comprises the chemically strengthened microcrystalline glass according to any one of the embodiments of the first aspect.

[0079] Compared with the prior art, one or more of the above technical solutions provided in the present application have the following advantages:

[0080] The present application makes the surface composition and stress structure of the chemically strengthened microcrystalline glass with lithium disilicate as the main crystal phase meet a specific relationship, so that the chemically strengthened microcrystalline glass can achieve good weather resistance while meeting a high stress level, and better meet the market application requirements. BRIEF DESCRIPTION OF DRAWINGS

[0081] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0082] Figure 1 The XRD pattern of the microcrystalline glass of Example 1.

[0083] Figure 2 The transmittance curve comparison diagram of the microcrystalline glass and the chemically strengthened microcrystalline glass of Example 1 in the 360nm-740nm wave band.

[0084] Figure 3 The XRD pattern comparison diagram of the microcrystalline glass and the chemically strengthened microcrystalline glass of Example 1.

[0085] Figure 4 The front side structure schematic diagram of the electronic device mentioned in the embodiments of the present application.

[0086] Figure 5 The back side structure schematic diagram of the electronic device mentioned in the embodiments of the present application.

[0087] Figure 6Structure diagram of an electronic device according to an embodiment of the present application.

[0088] Figure 7 Physical comparison diagram of the chemically strengthened glass provided for Comparative Example 1 before and after the high temperature and high humidity test, wherein (10a) is the chemically strengthened glass before the high temperature and high humidity test, and (10b) is the chemically strengthened glass taken out after the high temperature and high humidity test for 10 days.

[0089] Figure 8 Physical comparison diagram of the chemically strengthened glass provided for Comparative Example 2 before and after the high temperature and high humidity test, wherein (11a) is the chemically strengthened glass before the high temperature and high humidity test, and (11b) is the chemically strengthened glass taken out after the high temperature and high humidity test for 10 days.

[0090] Figure 9 Physical comparison diagram of the chemically strengthened glass provided for Comparative Example 3 before and after the high temperature and high humidity test, wherein (9a) is the chemically strengthened glass before the high temperature and high humidity test, and (9b) is the chemically strengthened glass taken out after the high temperature and high humidity test for 10 days.

[0091] Figure 10 Physical comparison diagram of the chemically strengthened glass provided for Comparative Example 1 before and after the high temperature and high humidity test, wherein (10a) is the chemically strengthened glass before the high temperature and high humidity test, and (10b) is the chemically strengthened glass taken out after the high temperature and high humidity test for 10 days.

[0092] Figure 11 Physical comparison diagram of the chemically strengthened glass provided for Comparative Example 2 before and after the high temperature and high humidity test, wherein (11a) is the chemically strengthened glass before the high temperature and high humidity test, and (11b) is the chemically strengthened glass taken out after the high temperature and high humidity test for 10 days.

[0093] The reference signs: 1-outer shell; 11-display screen cover plate; 12-back cover; 13-camera protection cover plate; 2-camera assembly; 3-middle frame; 4-display module. DETAILED DESCRIPTION

[0094] The embodiments of the present application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. The specific conditions not noted in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments not noted by the manufacturer are all conventional products that can be purchased on the market.

[0095] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not considered critical for the purposes of the application. The endpoints of the ranges and any values are provided as approximations only and are understood to be open-ended. Thus, the endpoints can be combined with one another to form ranges that are not expressly delineated. For example, a range of "1 to 10" can be combined with a range of "4 to 8" to form a range of "1 to 8", "1 to 4", "4 to 10", or "8 to 10." The same applies to any of the disclosed ranges and values. The term "optionally" means that the subsequently described event or circumstance can or can not occur, or that the subsequently identified item can or can not be present, is preferred, and does not necessarily make the application unpatentable. The term "and / or" means that the items can be combined together or used separately. The term "and / or" is inclusive.

[0096] Terminology and Test Methods:

[0097] In the present application, the glass-ceramics are a kind of solid composite materials containing both glass phase and crystal phase (or also called microcrystalline phase, crystalline phase) prepared by targeted and controlled heat treatment of base glass. The glass-ceramics are also called glass ceramics or crystallized glass.

[0098] In the present application, the chemically strengthened glass-ceramics are solid composite materials obtained by chemical strengthening treatment of the glass-ceramics. It should be understood that, during the chemical strengthening treatment, the alkali metal ions with large ionic radius (such as potassium ions or sodium ions) in the molten salt bath (or also called molten salt bath) will replace the alkali metal ions with small ionic radius (such as sodium ions or lithium ions) in the glass-ceramics, thereby generating exchange ion volume difference and generating compressive stress (or also called compression stress) on the surface of the glass-ceramics.

[0099] In the present application, the base glass refers to the glass that has not been subjected to nucleation treatment, crystallization treatment and strengthening treatment, or also called base glass.

[0100] In the present application, the composition at the center of the chemically strengthened glass-ceramics refers to the composition at or near the center of the depth or thickness of the chemically strengthened glass-ceramics, that is, the composition of the region in the chemically strengthened glass-ceramics that has not been subjected to ion exchange. It should be understood that the composition at the center of the chemically strengthened glass-ceramics is the same as or substantially the same as the composition of the glass-ceramics used to prepare the chemically strengthened glass-ceramics but has not been subjected to chemical strengthening treatment.

[0101] In the present application, the visible light wavelength range refers to 360 nm to 740 nm.

[0102] In the present application, the haze is the percentage of the transmitted light intensity deviating from the incident light by more than 2.5° in the total transmitted light intensity.

[0103] In the present application, the main crystal phase (or also called primary crystal phase) refers to the crystal phase with higher weight content (or also called weight percentage, mass percentage) than other crystal phases present in the glass-ceramics.

[0104] In the present application, the main surface refers to the surface with the largest surface area, such as the upper surface or the lower surface of a glass-ceramic sheet placed horizontally.

[0105] In the present application, the crystallinity refers to the percentage of the total mass of the crystalline phase or crystal in the glass-ceramic to the mass of the glass-ceramic, or also referred to as the total content of the crystalline phase in the glass-ceramic.

[0106] In the present application, when light of a certain wavelength is irradiated to the main surface of the glass-ceramic, the light will be reflected, absorbed and transmitted, and the ratio of the intensity of the transmitted part to the intensity of the incident light is the transmittance.

[0107] In the present application, the D65 light source is a light source for measuring the color of an object irradiated by sunlight containing ultraviolet region, with a color temperature of 6500K and a color rendering index Ra higher than 90, showing a wide spectral distribution in the visible wavelength region.

[0108] In the present application, the crystallized glass raw material refers to a glass raw material that has been heat treated for a period of time to achieve a certain crystallinity, but has not yet reached the target crystallinity, and can continue to crystallize to reach the target crystallinity under heat.

[0109] In the present application, CT_LD refers to the tensile stress linear density, with the unit of MPa / mm. It should be understood that after the glass-ceramic is placed in a molten salt bath for ion exchange, a compressive stress layer (or also referred to as a compressive stress layer) will be formed on the surface of the glass-ceramic, and a tensile stress layer (or also referred to as a tensile stress layer) will be formed inside the glass-ceramic. In the present application, during the chemical strengthening process, the alkali metal ions with larger radius in the molten salt bath are ion exchanged with the alkali metal ions with smaller radius in the glass-ceramic, thereby forming a compressive stress layer on the surface of the glass-ceramic and a tensile stress layer inside the glass-ceramic, i.e., a chemically strengthened glass-ceramic containing a compressive stress layer and a tensile stress layer is prepared. In the present application, CT_LD is calculated by the following formula:

[0110]

[0111] wherein t is the thickness of the chemically strengthened glass-ceramic, with the unit of mm; DOL_0 is the depth of the compressive stress layer of the chemically strengthened glass-ceramic, with the unit of μm; |CT_AV| is the absolute value of the average tensile stress of the chemically strengthened glass-ceramic, with the unit of MPa. It should be understood that in the calculation formula of the tensile stress linear density, the data is substituted into the calculation according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

[0112] In the present application, CS_50 refers to the compressive stress value at a depth of 50 μm from the main surface of the chemically strengthened glass-ceramic, with the unit of MPa, which is obtained by SLP-2000 stress meter testing.

[0113] In this application, |CT_AV| refers to the absolute value of the average tensile stress, in MPa. Specifically, it refers to the absolute value of the average value of all tensile stresses in the tensile stress layer, which is obtained by testing with an SLP-2000 stress meter.

[0114] In this application, DOL_0 refers to the compressive stress layer depth, or the compressive stress layer depth, specifically the distance from any main surface of the chemically strengthened glass-ceramic to the position near which the compressive stress is zero, obtained by testing with an SLP-2000 stress meter.

[0115] In this application, the aforementioned stress performance testing method is as follows: When testing the CS_50, DOL_0, and |CT_AV| of chemically strengthened glass-ceramics using an SLP-2000 stress meter, the relevant parameters of the stress meter are set as follows: light source wavelength is 518 nm, SOC (photoelastic coefficient) is set to 26 [(nm / cm) / MPa], refractive index is set to 1.56, and exposure time is set to 300 μsec. After measuring DOL_0 and |CT_AV|, the tensile stress linear density (CT_LD) value of the chemically strengthened glass-ceramics is calculated using the aforementioned formula for calculating tensile stress linear density.

[0116] In this application, the b-value is used to characterize the yellow-blue value of the material. The b-value in this application is the transmitted light b-value, and a positive b-value indicates that the material has a bluish tint.

[0117] In this application, Vickers hardness refers to that of Robert L. Smith and George Sedland.

[0118] E. Sandland proposed a standard for expressing the hardness of materials in 1921 at Vickers Ltd.

[0119] The Vickers hardness test method in this application is as follows: A small piece of microcrystalline glass or chemically strengthened microcrystalline glass with dimensions of 50mm × 50mm × 0.70mm is prepared. A clean glass sample without visible scratches, dents, cracks, or other damage is selected as the test sample. The Vickers hardness is then measured using a Vickers hardness tester. The Vickers hardness tester used in this application is the VTD405 digital display low-load Vickers hardness tester from Beijing Kewei Technology Co., Ltd. Test conditions: load 300gf, loading time 10s, and the validity of the indentation conforms to the standard "GB / T37900-2019 Test Method for Hardness and Fracture Toughness of Ultra-thin Glass: Low-load Vickers Hardness Indentation Method". Measurements are taken at three different locations on the surface of the same test sample, and the average of the three measurements is recorded as the Vickers hardness result of the test sample.

[0120] In the present application, Young's modulus is used to characterize the ability of glass to resist elastic deformation due to external force. In the present application, UMS-100 ultrasonic material characterization system is used to test the Young's modulus of the glass-ceramics by acoustic wave.

[0121] In the present application, nucleation treatment refers to the formation of stable crystal nucleus in the base glass by heat treatment; and crystallization treatment refers to the precipitation of target crystals or crystal phases in the base glass by heat treatment.

[0122] In the present application, the thickness of the glass-ceramics is measured by a micrometer. It should be understood that in the thickness direction, the ion exchange degree changes gradually from the surface to the center, and the total Na-K and / or Li-Na exchange amount is generally not more than 1.5% of the total mass of the sample, and the difference in ionic radius is pm level, so the expansion effect in the thickness direction is extremely slight, and the thickness can be approximately considered to be basically unchanged. That is, the thickness of the glass-ceramics changes very little before and after chemical strengthening, and can be basically ignored, and the thickness of the glass-ceramics is basically the same as that of the chemically strengthened glass-ceramics prepared therefrom.

[0123] In the present application, the size specifications of the glass-ceramics are measured by a two-dimensional measuring machine (instrument model Miyu MY-YXCL-4030).

[0124] In the present application, the crystal phase, crystallinity and average grain size of the glass-ceramics are determined by XRD test. Specifically as follows:

[0125] (1) XRD test: The glass-ceramics or chemically strengthened glass-ceramics of the present application are crushed and ground into samples with a particle size of less than 75 μm, and the ground samples are tested by X-ray diffractometer to obtain XRD diffraction peak curve and XRD diffraction data. In the present application, the X-ray diffractometer used is Shimadzu XRD-6100, the target material is copper, 2θ = 10°-50°, the scanning speed is 6° / min, the working voltage is 40 kV, and the working current is 30 mA.

[0126] (2) Determination of crystal phase: The XRD diffraction data are analyzed by Jade software (JADE Standard 8.6) to determine the crystal phase in the sample.

[0127] (3) Determination of crystallinity: The test results of XRD (RAW format) are imported into Jade software for fitting and calculation, and the crystallinity of the sample can be determined.

[0128] (4) Determination of average grain size: the data obtained by XRD test can be used to calculate the average grain size (or also known as average crystal size) of the sample according to the Scherrer formula D = Kλ / (βcosθ). Wherein, λ is the X-ray wavelength, λ = 0.154056 nm, β is the half-height width of the diffraction peak, K = 0.89, and θ is the Bragg diffraction angle. Specifically, the RAW format file output by the XRD instrument is curve-fitted in Jade software, and the fitting report is output by Jade. According to the angle 2θ value and the Peak FWHM value corresponding to each diffraction peak in the fitting report, the Peak FWHM value is converted to radian: β = (FWHM / 180×3.14), and the grain size of each diffraction peak is calculated by the Scherrer formula D = Kλ / (βcosθ) and then averaged to obtain the average grain size in the sample.

[0129] In the present application, reference is made to the national standard "GB / T 7962.12-2010 Colorless Optical Glass Test Methods Part 12: In-Spectrum Transmittance", and the transmittance, haze and b value of the microcrystalline glass of the present application are tested by a haze meter. Specifically, the transmittance, haze and b value of light of different wavelengths are tested by a haze meter for 5 pieces of microcrystalline glass in the same batch. The average of the b values and the haze values measured for the 5 pieces of microcrystalline glass are recorded as the b value result and the haze result of the microcrystalline glass, respectively. The average of the transmittance values measured for the 5 pieces of microcrystalline glass under 550 nm wavelength light is recorded as the transmittance result of the microcrystalline glass under 550 nm wavelength light. The haze meter used in the present application is a Japan Konica Minolta Spectrophotometer CM-3600A, the light receiving optical system is transmission, the spectral method is plane diffraction grating, the wavelength range is 360 nm-740 nm, the wavelength interval is 10 nm, the illumination light source is pulse xenon lamp x 4, and the instrument is placed in an environment with a temperature of 24°C and an air humidity of 40%.

[0130] In the present application, the anti-sandpaper drop height of each sample in the plurality of pieces of chemically strengthened microcrystalline glass samples of the same embodiment or the same comparative example is added together, and the value obtained by dividing the number of samples measured is recorded as the average anti-sandpaper drop height of the chemically strengthened microcrystalline glass tested, which is used to characterize the anti-drop damage performance of the chemically strengthened microcrystalline glass. Specifically, at least 10 samples are taken from each batch for testing, and the average anti-sandpaper drop height

[0131]

[0132] Wherein, n is the number of glass samples tested per batch, and hi is the anti-sandpaper drop height of a single sample test;

[0133] Wherein, the test method for the anti-sandpaper drop height of a single sample is as follows:

[0134] Step 1: Paste 80-mesh sandpaper on the lower surface of a 181g model machine, and place the model machine on a green chart LT-SKDL-CD type drop machine;

[0135] Step 2: Place a chemical-strengthened microcrystalline glass sample with a length, width and thickness of 50mmx50mmx0.7mm directly below the model machine, with the chemical-strengthened microcrystalline glass sample facing the sandpaper. Make the model machine impact the chemical-strengthened microcrystalline glass sample directly below it at a certain drop height. If the chemical-strengthened microcrystalline glass sample does not break, increase the drop height of the model machine in a certain manner, and continue to make the model machine impact the chemical-strengthened microcrystalline glass sample directly below it until the chemical-strengthened microcrystalline glass sample breaks. For example, the drop height of the model machine is 0.4m, and the sample is impacted once. If the sample does not break, the drop height of the model machine is increased by 0.1m, and the sample is impacted again. Repeat the foregoing process until the chemical-strengthened microcrystalline glass sample breaks.

[0136] Step 3: Record the last drop height before the chemical-strengthened microcrystalline glass sample breaks as its sandpaper drop height resistance. For example, if the drop height is increased by 0.1m each time, and the sample breaks when the drop height is 0.5m, then the sandpaper drop height resistance of the sample is 0.4m.

[0137] In this application, the test method for the surface Na2O mass percentage of the chemical-strengthened microcrystalline glass is as follows: the content of Na element on the surface of the chemical-strengthened microcrystalline glass is measured by an X-ray fluorescence spectrometer (XRF), and then the surface Na2O mass percentage is calculated. The device model used is (Thermo Scientific ARL PERFORM’X), the target material is Rh (rhodium), the light tube voltage is 30kV, the current is 80mA, the collimator is 0.40, the crystal selection is AxO3, the detector selection is FPC, the test range is a circle with a diameter of 29mm, and the test method uses the X_UQ method in the OXSAS analysis software.

[0138] In this application, the test method for the surface K2O mass percentage of the chemical-strengthened microcrystalline glass is as follows: the content of K element on the surface of the chemical-strengthened microcrystalline glass is measured by an X-ray fluorescence spectrometer (XRF), and then the surface K2O mass percentage is calculated. The device model used is (Thermo Scientific ARL PERFORM’X), the target material is Rh (rhodium), the light tube voltage is 40kV, the current is 60mA, the collimator is 0.15, the crystal selection is LiF200, the detector selection is FPC, the test range is a circle with a diameter of 29mm, and the test method uses the X_UQ method in the OXSAS analysis software.

[0139] In the present application, the concentration of elements or oxides with atomic number 6 and below in the chemically strengthened glass-ceramics is not tested when using the non-standard test for XRF testing. During testing, the chemically strengthened glass-ceramics sheet is directly cut into a suitable size (e.g., 34 mm*34 mm), placed flat in the sample box, and covered with the test aperture, and then the test can be performed.

[0140] In the present application, the high-temperature and high-humidity failure time of the chemically strengthened glass-ceramics is tested under the conditions of a test temperature of 85°C and a relative humidity of 85%, i.e., a high-temperature and high-humidity failure test is performed, and the weather resistance of the chemically strengthened glass-ceramics is characterized by the high-temperature and high-humidity failure test results. The high-temperature and high-humidity failure time is the total time from the start of the high-temperature and high-humidity test to the appearance of spots or whitish marks on the chemically strengthened glass-ceramics that cannot be wiped off.

[0141] In the present application, the high-temperature and high-humidity failure time of the chemically strengthened glass-ceramics is tested under the conditions of a test temperature of 85°C and a relative humidity of 85%, i.e., a high-temperature and high-humidity failure test is performed, and the weather resistance of the chemically strengthened glass-ceramics is characterized by the high-temperature and high-humidity failure test results. The high-temperature and high-humidity failure time is the total time from the start of the high-temperature and high-humidity test to the appearance of spots or whitish marks on the chemically strengthened glass-ceramics that cannot be wiped off.

[0142] Without being bound by any theory, when the lithium disilicate glass-ceramics with lithium disilicate crystal phase as the main crystal phase is chemically strengthened, mainly sodium-lithium ion exchange is carried out, which can improve the deep compressive stress and the depth of the compressive stress layer of the glass, but after the exchange, the sodium-rich layer is easily formed on the surface of the glass-ceramics. If the surface sodium content is too high, the environmental durability (or also known as weather resistance) of the chemically strengthened glass-ceramics will be poor. After long-term use in sweat or in a humid environment, the surface smoothness of the chemically strengthened glass-ceramics product will decrease, the surface will become rough, and more seriously, it will be foggy or whitish, or form spots that cannot be wiped off. Not only will this reduce the user's touch on the screen, but the fogging, whitening, and spotting will also reduce the display effect and appearance of the glass screen. Moreover, if the spots, fogging, or whitening occur at the camera position, it will also seriously affect the camera effect of the mobile phone and reduce the service life of the device. However, if the surface sodium content of the chemically strengthened (ion exchanged) glass-ceramics is too low, the compressive stress formed by sodium-lithium ion exchange will be relatively low, which will lead to a relatively low mechanical strength of the chemically strengthened glass-ceramics, making it unable to meet the use requirements.

[0143] Therefore, in order to maintain high stress and excellent mechanical strength performance while taking into account good weather resistance, the present application provides a chemically strengthened glass-ceramics with good weather resistance and high stress. By making the surface composition and stress of the chemically strengthened glass-ceramics with lithium disilicate as the main crystal phase satisfy a specific relationship, the present application provides a chemically strengthened glass-ceramics with a relatively high stress level, which can ensure a relatively high mechanical strength performance, while having good environmental durability or weather resistance. It can be understood that the surface composition can be the material composition or component distribution of the surface of the substrate glass, glass-ceramics, or chemically strengthened glass-ceramics, or the mass percentage of a certain component, the molar percentage of a certain component, the mass percentage relationship between two or more material components, the mass content relationship between two or more material components, or the molar content relationship between two or more material components, or a combination of the above, and others. For example: the mass percentage of Na2O on the surface of the chemically strengthened glass-ceramics or the mass percentage of K2O on the surface of the chemically strengthened glass-ceramics, for example: the content relationship between Na2O on the surface of the chemically strengthened glass-ceramics and K2O on the surface of the chemically strengthened glass-ceramics, for example: the mass percentage relationship between Na2O on the surface of the chemically strengthened glass-ceramics and K2O on the surface of the chemically strengthened glass-ceramics.

[0144] In some embodiments of the present application, a chemically strengthened glass-ceramic is provided, the chemically strengthened glass-ceramic comprising lithium disilicate crystal phase, wherein the lithium disilicate crystal phase has a larger mass percentage than other crystal phases present in the chemically strengthened glass-ceramic; the chemically strengthened glass-ceramic has a compressive stress layer on the surface and a tensile stress in the interior; the chemically strengthened glass-ceramic satisfies:

[0145] N = n * (CT_LD - 50000) / 10000, -32.5 < N < 15, preferably, -28.0 < N < 0, more preferably, -20.0 < N < -2.5,

[0146] wherein n = (mass percentage of Na2O on the surface of the chemically strengthened glass-ceramic / mass percentage of K2O on the surface of the chemically strengthened glass-ceramic) 2 The mass percentage of Na2O on the surface of the chemically strengthened glass-ceramic and the mass percentage of K2O on the surface of the chemically strengthened glass-ceramic are determined by XRF; CT_LD is the tensile stress linear density, in units of MPa / mm; in the formula N, the data are substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

[0147] The lithium disilicate (Li2Si2O5) crystal phase is an orthorhombic crystal based on [Si2O5] tetrahedral array, and the shape of the crystal is flat or plate-like. In the interior of the glass-ceramic, the lithium disilicate crystals are randomly oriented interlocking microstructures, which force the path of a crack to twist when the crack passes through the crystals, thereby preventing the propagation of the crack and improving the strength and fracture toughness of the glass-ceramic. At the same time, the optical refractive index of the lithium disilicate crystal is close to the glass matrix (such as the base glass used to prepare the glass-ceramic in the present application), which is an ideal crystal phase for preparing high-transparency glass-ceramics. In the present application, the glass-ceramic comprises a structure in which lithium disilicate is the main crystal phase, which is beneficial to ensuring that it has high intrinsic strength (or also known as inherent strength) and excellent optical performance.

[0148] In the present application, by making the chemically strengthened glass-ceramic satisfy the requirements of the specific crystal phase structure and the formula N, the chemically strengthened glass-ceramic can achieve good weather resistance while satisfying a high stress level, and can better ensure that the chemically strengthened glass-ceramic meets the application requirements.

[0149] In some embodiments, the value of formula N can be -30 to 10, -25 to 5, -20 to 0, -15 to -2 or -10 to -2.5, etc. In some embodiments, the value of formula N can be -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 a value within a range defined by any two of the above-mentioned specific values as endpoints, as long as the chemically strengthened glass-ceramics with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above-mentioned ranges can be combined with any other range, as long as the chemically strengthened glass-ceramics with desired properties of the present application can be obtained.

[0150] In some embodiments of the present application, the chemically strengthened glass-ceramics satisfy 45000 MPa / mm≤CT_LD≤52000 MPa / mm, preferably 45900 MPa / mm≤CT_LD≤50000 MPa / mm, and more preferably 47500 MPa / mm≤CT_LD≤50000 MPa / mm. By making the CT_LD of the chemically strengthened glass-ceramics not less than 45000 MPa / mm, it is beneficial to ensure that the tensile stress stored inside the chemically strengthened glass-ceramics is dense enough, thereby ensuring that it has a high surface stress level, thereby facilitating the stress structure to play a role in improving the mechanical strength performance, and ensuring that it obtains excellent damage resistance, such as excellent rough surface drop damage resistance, to meet market demand.

[0151] In some embodiments, the CT_LD of the chemically strengthened glass-ceramics can be 45000 MPa / mm to 50000 MPa / mm, 45500 MPa / mm to 49500 MPa / mm, 46000 MPa / mm to 49000 MPa / mm, 46500 MPa / mm to 48500 MPa / mm, or 46000 MPa / mm to 48000 MPa / mm. In some embodiments, the CT_LD of the chemically strengthened glass-ceramics can be 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 defined by any two of the foregoing specific values as endpoints, as long as a chemically strengthened glass-ceramics with desired properties of the present application is obtained. It should be understood that in specific embodiments, any of the foregoing ranges can be combined with any other range, as long as a chemically strengthened glass-ceramics with desired properties of the present application is obtained.

[0152] In some embodiments of the present application, the surface Na2O content of the chemically strengthened glass-ceramics is 5% to 8.5%, preferably 5.5% to 7.5%, in terms of mass percentage of oxide, as determined by XRF; and / or, in some embodiments of the present application, the surface K2O content of the chemically strengthened glass-ceramics is 0.7% to 2.0%, preferably 0.7% to 1.5%, in terms of mass percentage of oxide, as determined by XRF. By having the surface K element or the surface Na element of the chemically strengthened glass-ceramics satisfy a specific range, it is beneficial to achieve good weather resistance while obtaining a high stress level.

[0153] In some embodiments, the surface Na20 content of the chemically strengthened glass-ceramics can be 5%, 5.30%, 6.12%, 7.00%, 5.21%, 6.32%, 5.17%, 6.36%, 7%, 7.5%, 8%, or 8.5%, or a value within a range bounded by any two of the foregoing specific values, as measured by XRF in mass percent of oxides, provided that a chemically strengthened glass-ceramic having the desired properties of the present application is obtained. It should be understood that in specific embodiments, any of the foregoing ranges can be combined with any other range, provided that a chemically strengthened glass-ceramic having the desired properties of the present application is obtained.

[0154] In some embodiments, the surface K20 content of the chemically strengthened glass-ceramics can be 0.7%, 1.25%, 0.81%, 0.77%, 1.24%, 0.80%, 1.26%, 1.5%, 1.8%, or 2.0%, or a value within a range bounded by any two of the foregoing specific values, as measured by XRF in mass percent of oxides, provided that a chemically strengthened glass-ceramic having the desired properties of the present application is obtained. It should be understood that in specific embodiments, any of the foregoing ranges can be combined with any other range, provided that a chemically strengthened glass-ceramic having the desired properties of the present application is obtained.

[0155] In some embodiments of the present application, the Na20 content in the center of the chemically strengthened glass-ceramics is 3% to 3.5% in mass percent of oxides, preferably, the Na20 content in the center of the chemically strengthened glass-ceramics is 3.1% to 3.2% in mass percent of oxides. It should be understood that in the present application, the Na20 content in the center of the chemically strengthened glass-ceramics is 3% to 3.5% in mass percent of oxides, which means that the Na20 content in the center of the chemically strengthened glass-ceramics is 3% to 3.5% in mass percent of oxides.

[0156] In some embodiments, the mass percentage of Na2O in the composition at the center of the chemically strengthened glass-ceramics can be 3.1% to 3.4%, 3.1% to 3.3%, or 3% to 3.2%, in terms of mass percentage of oxides. In some embodiments, the mass percentage of Na2O in the composition at the center of the chemically strengthened glass-ceramics can be 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%, in terms of mass percentage of oxides, or a value within a range defined by any two of the foregoing specific values as endpoints, as long as a chemically strengthened glass-ceramics with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the foregoing ranges can be combined with any other range, as long as a chemically strengthened glass-ceramics with desired properties of the present application can be obtained.

[0157] In some embodiments of the present application, the concentration of Na ions in the chemically strengthened glass-ceramics varies at least in a portion of the compressive stress layer and reaches a minimum Na ion concentration at the contact with the tensile stress layer, and the chemically strengthened glass-ceramics satisfies:

[0158] Y = ΔC x ((CT_LD - 50000) / 100) 2 Y < 60, preferably Y ≤ 50, more preferably Y ≤ 20,

[0159] wherein ΔC is the difference between the mass percentage of Na2O at the surface of the chemically strengthened glass-ceramics and the mass percentage of Na2O at the center of the chemically strengthened glass-ceramics, and the mass percentage of Na2O at the surface of the chemically strengthened glass-ceramics is determined by XRF; CT_LD is the tensile stress linear density, in units of MPa / mm, and in the formula Y, the data is substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

[0160] In the present application, by making the chemically strengthened glass-ceramics satisfy the requirements of the specific crystalline structure and the formula Y, it is beneficial to make the chemically strengthened glass-ceramics achieve a high stress level.

[0161] In some embodiments, the value of Formula Y can be < 60, < 55, < 50, < 45, < 40, < 35, < 30, < 25, < 20, < 15, < 10, or < 5. In some embodiments, the value of Formula Y can be 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 between any two of the specifically mentioned values, as long as the chemically strengthened glass with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the chemically strengthened glass with desired properties of the present application can be obtained.

[0162] In some embodiments of the present application, the chemically strengthened glass satisfies 75 MPa < |CT_AV| < 120 MPa, preferably 77 MPa < |CT_AV| < 90 MPa, where |CT_AV| is the absolute value of the average tensile stress. By keeping |CT_AV| of the chemically strengthened glass at a suitable level, it is beneficial to ensure that the chemically strengthened glass has a desired tensile stress layer distribution structure, and it is beneficial to ensure that it has a high surface stress level. A higher surface compressive stress level can offset more residual energy from a drop, crush, puncture, impact, or collision, and thus it is beneficial to ensure that the chemically strengthened glass has excellent damage resistance.

[0163] In some embodiments, |CT_AV| of the chemically strengthened glass can be 80 MPa to 115 MPa, 85 MPa to 110 MPa, 90 MPa to 105 MPa, or 93 MPa to 102 MPa. In some embodiments, |CT_AV| of the chemically strengthened glass can be 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 a value within a range between any two of the specifically mentioned values, as long as the chemically strengthened glass with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the chemically strengthened glass with desired properties of the present application can be obtained.

[0164] In some embodiments of the present application, the chemically strengthened glass-ceramics satisfies: DOL_0 is 0.18t-0.25t, preferably, 0.20t-0.25t, wherein DOL_0 is the depth of compressive stress layer, and t is the thickness of the chemically strengthened glass-ceramics. By satisfying the appropriate proportional relationship between the depth of compressive stress layer and the thickness of the chemically strengthened glass-ceramics, it is beneficial to ensure that the chemically strengthened glass-ceramics is in a relatively optimal stress distribution state, and thus it is beneficial to exert the improvement effect of the stress structure on the mechanical strength performance.

[0165] In some embodiments, the value of DOL_0 / t of the chemically strengthened glass-ceramics can be 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24 or 0.25, or a value within a numerical range constituted by any two of the above specific numerical values as endpoints, as long as the chemically strengthened glass-ceramics with the required performance of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the chemically strengthened glass-ceramics with the required performance of the present application can be obtained.

[0166] In some embodiments of the present application, the chemically strengthened glass-ceramics satisfies: CS_50 is 150MPa-250MPa, preferably, 160MPa-180MPa, wherein CS_50 refers to the compressive stress value at a depth of 50μm from the main surface of the chemically strengthened glass-ceramics. By making the chemically strengthened glass-ceramics have a relatively high surface stress level, it can offset more residual energy of drop, extrusion, impact or collision, and thus it is beneficial to ensure that it has excellent damage resistance performance, such as excellent drop resistance performance.

[0167] In some embodiments, the CS_50 of the chemically strengthened glass-ceramics can be 150MPa, 160MPa, 170MPa, 180MPa, 190MPa, 210MPa, 220MPa, 230MPa, 240MPa, 250MPa, 162.81MPa, 166.33MPa, 170.25MPa, 165.17MPa, 169.43MPa, 167.89MPa, 170.28MPa or 200MPa, or a value within a numerical range constituted by any two of the above specific numerical values as endpoints, as long as the chemically strengthened glass-ceramics with the required performance of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the chemically strengthened glass-ceramics with the required performance of the present application can be obtained.

[0168] It is understood that the chemically strengthened glass-ceramics of the present application are made from a glass-ceramic that is chemically strengthened, and the composition at the center of the chemically strengthened glass-ceramics is the same or substantially the same as the composition of the glass-ceramic. Compared to the glass-ceramic before the chemical strengthening process (which involves ion exchange), the composition at the surface of the glass-ceramic article after the chemical strengthening process can be different from the composition of the glass-ceramic before the chemical strengthening process. This is because, during the chemical strengthening process, one type of alkali metal ions (e.g., Li + or Na + ) at the surface of the just-formed glass-ceramic is replaced by a larger alkali metal ion (e.g., Na + or K + ), respectively. However, in embodiments, the glass composition and phase assemblage at or near the center of the depth or thickness of the glass-ceramic article still have the composition and phase assemblage of the just-formed glass-ceramic. That is, in the present application, the composition (e.g., the composition of the compressive stress layer) and phase assemblage at the center of the chemically strengthened glass-ceramics that are chemically strengthened are the same or substantially the same as the glass-ceramics that are not chemically strengthened.

[0169] In the present application, the glass-ceramics used to make the chemically strengthened glass-ceramics can be made from a base glass that is heat treated, and the composition of the base glass is the same or substantially the same as the composition of the glass-ceramics in terms of mole percent of oxides.

[0170] In some embodiments of the present application, the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used to make the chemically strengthened glass-ceramics or the composition of the base glass in terms of mole percent of oxides comprises: 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 the specific glass composition, it is beneficial to obtain a glass-ceramic that satisfies a specific crystal phase structure, and it is beneficial to obtain a chemically strengthened glass-ceramic that satisfies a specific stress structure.

[0171] In the present application, SiO2 is an essential component for forming a glass network structure and is also one of the main components for forming lithium disilicate crystals. The higher the content of SiO2 in the glass system, the denser the network structure of the glass phase, and accordingly, the higher the mechanical strength of the glass-ceramics, the smaller the thermal expansion coefficient, and the better the heat resistance, dielectric properties and chemical stability. However, if the content of SiO2 is too high, the melting temperature of the base glass will be too high, the molten viscosity will be large, and the forming difficulty of the base glass will be increased. If the content of SiO2 is too low, the weather resistance of the glass will be reduced. Therefore, in order to balance the formability of the glass and the excellent properties, in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used for preparing the chemically strengthened glass-ceramics or the composition of the base glass, the content of SiO2 is 61.50% to 63.40% by mole, preferably 61.50% to 63.30% by mole, and more preferably 62.00% to 62.60% by mole.

[0172] In some embodiments of the present application, in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used for preparing the chemically strengthened glass-ceramics or the composition of the base glass, the content of SiO2 can be 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%, 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% by mole, or can be a value within a range formed by any two of the above specific values as endpoints, as long as a glass-ceramics or a chemically strengthened glass-ceramics with the required properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or a chemically strengthened glass-ceramics with the required properties of the present application can be obtained.

[0173] In the present application, Al2O3 is a component forming a glass network structure, and appropriate amount of Al2O3 is beneficial to improve the chemical strengthening effect of the glass-ceramics, and can improve the weather resistance of the glass, and to a certain extent, is beneficial to promote the ion exchange in the chemical strengthening process. However, excessive Al2O3 can increase the viscosity of the glass, and easily lead to the precipitation of other crystal phases, such as petalite, etc., which affects the crystal phase structure of the glass-ceramics. Therefore, in order to obtain the desired crystal phase structure and improve the chemical strengthening effect of the glass-ceramics, the molar percentage of Al2O3 in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used for preparing the chemically strengthened glass-ceramics or the composition of the substrate glass is 2.75% to 2.99%.

[0174] In some embodiments of the present application, the content of Al2O3 in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used for preparing the chemically strengthened glass-ceramics or the composition of the substrate glass, in terms of molar percentage of oxides, can be 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 can be a value within a value range formed by any two of the above specific values as endpoints, as long as a glass-ceramics or a chemically strengthened glass-ceramics with the required properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or a chemically strengthened glass-ceramics with the required properties of the present application can be obtained.

[0175] In the present application, P2O5 acts as a nucleating agent, and has the effect of promoting uniform nucleation of the glass. When the content of P2O5 is too low or too high, it will lead to poor crystallization effect, affect the optical properties of the obtained glass-ceramics, and reduce the transparency of the glass-ceramics. Therefore, in order to obtain the desired crystal phase structure and achieve excellent optical properties and excellent mechanical strength properties, the molar percentage of P2O5 in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used for preparing the chemically strengthened glass-ceramics or the composition of the substrate glass is 0.91% to 1.91%, preferably 1.20% to 1.91%, and more preferably 1.30% to 1.60%.

[0176] In some embodiments of the present application, the content of P2O5 in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the chemically strengthened glass-ceramics or the composition of the base glass can be 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% in terms of mole percent of oxide, or can be a value within a range of values formed by any two of the above specific numerical values as endpoints, as long as a glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0177] In the present application, ZrO2 is an intermediate oxide for glass formation, and an appropriate amount of ZrO2 can improve the chemical stability of the glass-ceramics, increase the hardness of the glass-ceramics, and increase the scratch resistance and drop resistance of the glass-ceramics, and can also improve the weather resistance of the glass. In addition, due to the high cation charge and strong field of ZrO2, it has a large accumulation effect on the structure of the glass, and is also commonly used as a nucleating agent in glass-ceramics. However, too high a content of ZrO2 can cause the glass to phase separate or be detrimental to obtaining glass-ceramics with excellent optical properties. Therefore, in order to obtain glass-ceramics with excellent optical properties and high mechanical strength, the content of ZrO2 in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the chemically strengthened glass-ceramics or the composition of the base glass is 4.20% to 4.85% in terms of mole percent, and is preferably 4.20% to 4.60%.

[0178] In some embodiments of the present application, the content of ZrO2 in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the chemically strengthened glass-ceramics or the composition of the base glass can be 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% in terms of mole percent of oxide, or can be a value within a range of values formed by any two of the above specific numerical values as endpoints, as long as a glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0179] In the present application, Na2O is an extra-network oxide, and appropriate amount of Na2O can provide free oxygen, improve the viscosity of the glass, promote the melting and fining of the glass liquid, and also adjust the chemical strengthening rate, but excessive Na2O not only reduces the crystallinity of the glass-ceramics, but also affects the chemical strengthening effect of the glass-ceramics. Therefore, in order to improve the formability of the substrate glass and the chemical strengthening effect of the glass-ceramics, the molar percentage of Na2O in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the chemically strengthened glass-ceramics or the composition of the substrate glass is 1.80% to 3.20%, preferably 1.85% to 3.05%, and more preferably 2.20% to 3.00%.

[0180] In some embodiments of the present application, the content of Na2O in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the chemically strengthened glass-ceramics or the composition of the substrate glass, in terms of molar percentage of oxides, can be 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%, 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 a value within a range formed by any two of the above specific values as endpoints, as long as a glass-ceramics or a chemically strengthened glass-ceramics with the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or a chemically strengthened glass-ceramics with the desired properties of the present application can be obtained.

[0181] In the present application, B2O3 as a flux can reduce the high-temperature viscosity of the glass, improve the melting difficulty caused by ZrO2, and lower the sagging temperature of the glass, but excessive B2O3 easily leads to a decrease in the transparency of the glass-ceramics. In addition, different structures are formed at different contents of B2O3, which greatly affects the weather resistance of the glass, which is specifically manifested as follows: B 3+ ions in the glass, and the B 3+ ions are in [BO4] tetrahedron, which reconnects the broken bonds in the glass caused by alkali metal ions, thereby playing a role in improving weather resistance. With the increase of the content of B2O3, B 3+The structure of the ion is converted to a [BO3] triangle, which in turn causes the weather resistance to decrease. Therefore, in order to improve the formability of the base glass while obtaining a glass-ceramic with desired properties, the molar percentage of B2O3 in the composition at the center of the chemically strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the chemically strengthened glass-ceramic or the composition of the base glass is 0-1.00%, preferably 0-0.65%.

[0182] In some embodiments of the present application, the content of B2O3 in the composition at the center of the chemically strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the chemically strengthened glass-ceramic or the composition of the base glass can be 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% in terms of molar percentage of oxide, or can be a value within a value range consisting of any two of the above specific values as endpoints, as long as a glass-ceramic or chemically strengthened glass-ceramic with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or chemically strengthened glass-ceramic with desired properties of the present application can be obtained.

[0183] In the present application, Li2O is an essential component for forming the main crystalline phase lithium disilicate crystalline phase and also an essential component for providing lithium ions for ion exchange during the chemical strengthening process. An appropriate amount of Li2O not only helps to improve the viscosity of the glass, promote the melting and fining of the glass liquid, but also helps to ensure that the desired content of lithium disilicate crystals is obtained, and at the same time, Li2O can also provide alkali lithium ions for ion exchange with large radius ions (such as sodium ions) in the molten salt bath, which is an important factor affecting the stress level that can be obtained by the chemically strengthened glass-ceramic. However, excessive Li2O can deteriorate the optical properties of the glass-ceramic. Therefore, in order to improve the formability of the base glass, obtain a glass-ceramic with a desired structure, and improve the chemical strengthening effect of the glass-ceramic, the molar percentage of Li2O in the composition at the center of the chemically strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the chemically strengthened glass-ceramic or the composition of the base glass is 25.32%-26.52%, preferably 25.52%-26.52%, more preferably 25.52%-26.00%.

[0184] In some embodiments of the present application, the content of Li2O in the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used for preparing the chemically strengthened glass-ceramics or the composition of the substrate glass can be 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%, 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% in terms of mole percentage of oxides, or can be a value within a range defined by any two of the above specific values as endpoints, as long as a glass-ceramics or a chemically strengthened glass-ceramics with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or a chemically strengthened glass-ceramics with desired properties of the present application can be obtained.

[0185] Both Na2O and Li2O belong to alkali metal oxides, and they have the common feature of being able to destroy Si-O bonds in the glass, break the glass network, and reduce the high-temperature viscosity of the glass. However, if the amount added is too large, the weather resistance of the glass will be significantly impaired. The addition of multiple alkali metal oxides to the glass component will produce a complex “synergistic effect”, and the performance of the glass will not change linearly with the addition of a single alkali metal. This phenomenon in which the performance of the glass does not change linearly when multiple alkali metal oxides are added to the glass is referred to as “mixed alkali effect”. For example, the weather resistance of the glass is improved by the addition of several alkali metal oxides to the glass component, which is more beneficial than the addition of a single alkali metal oxide. However, there is also a certain limit, and too much or too little will make it difficult to obtain the desired effect.

[0186] In the present application, on the basis of adjusting and controlling the content range of each oxide component, by adjusting and controlling the ratio relationship between each oxide component, especially the mole percentage relationship between Na2O, B2O3, ZrO2 or Li2O, it is beneficial to ensure that a glass-ceramics with desired crystal phase structure is obtained, and at the same time, it is beneficial to ensure that the glass-ceramics has excellent optical performance and high intrinsic strength.

[0187] In some embodiments of the present application, the molar percentage of Na20 [Na20], the molar percentage of B203[B203], and the molar percentage of Zr02[Zr02] in the composition at the center of the chemically strengthened glass-ceramics or in the composition of the glass-ceramics used to make the chemically strengthened glass-ceramics or in the composition of the base glass satisfy the following relationship:

[0188] Z = -1.344 x (2.65 - 100 x [Na20])2+ 0.466 x 100 x [B203] + 1.203 x 100 x [Zr02], 4.80 < Z < 5.35.

[0189] Z < 5.35, preferably, 5.05 < Z < 5.25.

[0190] In some embodiments, the value of the molar percentage relationship Z between Na20, B203, and Zr02in the composition at the center of the chemically strengthened glass-ceramics or in the composition of the glass-ceramics used to make the chemically strengthened glass-ceramics or in the composition of the base glass can be 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 can be a value within a range of values defined by any two of the above specific values as endpoints, as long as a glass-ceramics or a chemically strengthened glass-ceramics with the desired properties of the present application is obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or a chemically strengthened glass-ceramics with the desired properties of the present application is obtained.

[0191] In some embodiments of the present application, the molar percentage of Na20 [Na20] and the molar percentage of B203[B203] in the composition at the center of the chemically strengthened glass-ceramics or in the composition of the glass-ceramics used to make the chemically strengthened glass-ceramics or in the composition of the base glass satisfy the following relationship: 0.90% < [Na20] - [B203] < 3.10%, preferably, 2.00% < [Na20] - [B203] < 3.00%, more preferably, 2.30% < [Na20] - [B203] < 3.00%.

[0192] In some embodiments, the difference in mole percent between Na20 and B203, [Na20] - [B203], in the composition at the center of the chemically strengthened glass-ceramic or in the composition of the glass-ceramic used to make the chemically strengthened glass-ceramic or in the composition of the base glass, can be 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%, 2.05%, 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 a value within a range having any two of the above specifically stated values as endpoints, as long as a glass-ceramic or chemically strengthened glass-ceramic having the desired properties of the present application is obtained. It will be appreciated that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as a glass-ceramic or chemically strengthened glass-ceramic having the desired properties of the present application is obtained.

[0193] In some embodiments of the present application, the ratio of the mole percent of Na20, [Na20], to the mole percent of Li20, [Li20], in the composition at the center of the chemically strengthened glass-ceramic or in the composition of the glass-ceramic used to make the chemically strengthened glass-ceramic or in the composition of the base glass, satisfies the following relationship: 8.55 < [Li20] / [Na20] < 13.85, preferably, 8.60 < [Li20] / [Na20] < 11.00.

[0194] In some embodiments, the ratio of the mole percent of Li20, [Li20], to the mole percent of Na20, [Na20], [Li20] / [Na20], in the composition at the center of the chemically strengthened glass-ceramic or in the composition of the glass-ceramic used to make the chemically strengthened glass-ceramic or in the composition of the base glass, can 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 a value within a range having any two of the above specifically stated values as endpoints, as long as a glass-ceramic or chemically strengthened glass-ceramic having the desired properties of the present application is obtained. It will be appreciated that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as a glass-ceramic or chemically strengthened glass-ceramic having the desired properties of the present application is obtained.

[0195] In some embodiments of the present application, the composition at the center of the chemically strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the chemically strengthened glass-ceramics or the composition of the base glass can further include other components on the basis of the above-mentioned composition ranges, as long as the glass-ceramics or the chemically strengthened glass-ceramics having the desired properties of the present application can be obtained. For example, in some embodiments, the composition at the center of the chemically strengthened glass-ceramics can further include CaO: 0.00-1.00 mol%, K2O: 0.00-1.00 mol%, in terms of mole percentage of oxides.

[0196] It should be understood that, in the present application, the crystalline structure of the glass-ceramics does not change significantly after the chemical strengthening treatment to obtain the chemically strengthened glass-ceramics, i.e., the crystallinity, average grain size and optical properties of the glass-ceramics are the same as or substantially the same as those of the chemically strengthened glass-ceramics. For example, reference can be made to the comparative examples of Figure 2 Figure 3 Similarly, it should be understood that the stress structure generated during the chemical strengthening process can improve the mechanical properties of the glass product. In the present application, the mechanical properties such as Young's modulus and Vickers hardness of the glass-ceramics do not decrease after the chemical strengthening treatment to obtain the chemically strengthened glass-ceramics, i.e., when the Young's modulus of the glass-ceramics is greater than 100 GPa, the Young's modulus of the chemically strengthened glass-ceramics obtained therefrom should also be greater than 100 GPa.

[0197] ​In the present application, "the lithium disilicate crystal phase has a greater mass percentage than other crystal phases present in the chemically strengthened microcrystalline glass" or "lithium disilicate as the main crystal phase" or other similar expressions refer to the lithium disilicate crystal phase accounts for more than 70 mass percent of all crystal phases of the microcrystalline glass or chemically strengthened microcrystalline glass according to the embodiments of the present application. In some embodiments, the mass of the lithium disilicate crystal phase accounts for more than 70% of all crystal phases of the microcrystalline glass used to prepare the chemically strengthened microcrystalline glass or the chemically strengthened microcrystalline glass, preferably, the mass of the lithium disilicate crystal phase accounts for more than 85% of all crystal phases of the microcrystalline glass used to prepare the chemically strengthened microcrystalline glass or the chemically strengthened microcrystalline glass. For example, the mass percentage (or also referred to as the weight percentage) of the lithium disilicate crystal phase in all crystal phases of the microcrystalline glass used to prepare the chemically strengthened microcrystalline glass or the chemically strengthened microcrystalline glass can 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 a value within a value range formed by any two specific values as endpoints, as long as a microcrystalline glass or chemically strengthened microcrystalline glass with the required performance of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a microcrystalline glass or chemically strengthened microcrystalline glass with the required performance of the present application can be obtained.

[0198] In some embodiments of the present application, the crystallinity of the microcrystalline glass or the chemically strengthened microcrystalline glass is more than 45%, preferably, the crystallinity of the microcrystalline glass or the chemically strengthened microcrystalline glass is 45% to 85%, more preferably, the crystallinity of the microcrystalline glass or the chemically strengthened microcrystalline glass is 55% to 65%. The higher the crystallinity of the microcrystalline glass or the chemically strengthened microcrystalline glass, the more conducive to obtaining high impact resistance and high intrinsic strength of the microcrystalline glass or the chemically strengthened microcrystalline glass. However, too high crystallinity not only affects the chemical strengthening effect of the microcrystalline glass, prolonging the chemical strengthening time of the microcrystalline glass to obtain a chemically strengthened microcrystalline glass with high stress level, but also affects the optical performance of the microcrystalline glass. In the present application, by making the microcrystalline glass meet the desired crystallinity, it is conducive to ensuring that the microcrystalline glass has excellent optical performance while meeting better impact resistance and high intrinsic strength, and at the same time, it is conducive to improving the chemical strengthening effect.

[0199] In some embodiments of the present application, the crystallinity of the glass-ceramic or the chemically strengthened glass-ceramic can be 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85%, or can be a value within a range defined by any two of the above specific values as endpoints, as long as the glass-ceramic or the chemically strengthened glass-ceramic having the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the glass-ceramic or the chemically strengthened glass-ceramic having the desired properties of the present application can be obtained.

[0200] In some embodiments of the present application, non-limiting examples of other possible crystalline phases in the glass-ceramic or the chemically strengthened glass-ceramic include lithium phosphate crystalline phase. In some embodiments, it is preferred that the glass-ceramic or the chemically strengthened glass-ceramic does not contain petalite crystalline phase. "Does not contain petalite crystalline phase" herein includes that the content of petalite crystalline phase is 0, or the content is not more than 0.1%. By controlling the precipitation of other crystalline phases, it is more beneficial to ensure that lithium disilicate forms the desired interlocking structure, thereby ensuring that the glass-ceramic or the chemically strengthened glass-ceramic obtains high mechanical strength performance, excellent optical performance, and excellent damage resistance performance.

[0201] In some embodiments of the present application, the average grain size of the glass-ceramic or the chemically strengthened glass-ceramic is 40 nm or less, preferably, the average grain size is 15-35 nm. The appropriate average grain size is beneficial to make the glass-ceramic have excellent optical performance and high intrinsic strength, while if the average grain size is too high, the glass-ceramic is easy to lose transparency, and the chemical strengthening effect will also be affected. In the present application, by making the glass-ceramic meet the appropriate average grain size, it is beneficial to make the glass-ceramic have excellent optical performance while meeting better impact resistance performance and high intrinsic strength, and at the same time, it is beneficial to improve the chemical strengthening effect.

[0202] In some embodiments, the average grain size of the glass-ceramic or the chemically strengthened glass-ceramic can be 40 nm, 35 nm, 30 nm, 25 nm, 20 nm, 15 nm, or 10 nm, or can be a value within a range defined by any two of the above specific values as endpoints, as long as the glass-ceramic or the chemically strengthened glass-ceramic having the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the glass-ceramic or the chemically strengthened glass-ceramic having the desired properties of the present application can be obtained.

[0203] In some embodiments of the present application, the glass-ceramic or the chemically strengthened glass-ceramic is transparent in the visible wavelength range, preferably, the transmittance of the glass-ceramic or the chemically strengthened glass-ceramic is ≥ 90.00% for 550 nm wavelength light at a thickness of 0.70 mm, preferably the transmittance is > 90.40%. The chemically strengthened glass-ceramic satisfying the transmittance can ensure good light transmittance, good transparent effect, and is suitable for use in display screens with requirements for display effect. The "visible wavelength range" herein refers to light with a wavelength of 360 nm-740 nm.

[0204] In some embodiments, the transmittance of the glass-ceramic or the chemically strengthened glass-ceramic can be 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% for 550 nm wavelength light at a thickness of 0.70 mm, or a value within a numerical range formed by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or a chemically strengthened glass-ceramic with the required properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or a chemically strengthened glass-ceramic with the required properties of the present application can be obtained.

[0205] In some embodiments of the present application, the haze of the glass-ceramic or the chemically strengthened glass-ceramic is < 0.30% at a thickness of 0.70 mm. Haze is the cloudy or hazy appearance of the glass-ceramic or the chemically strengthened glass-ceramic inside or on the surface due to light diffusion, and the smaller the haze, the better the transparent effect and display effect of the glass-ceramic or the chemically strengthened glass-ceramic. In some embodiments, the haze of the glass-ceramic or the chemically strengthened glass-ceramic can be 0.25%, 0.20%, 0.15%, 0.10%, 0.05%, 0.21%, 0.14%, 0.13%, 0.15%, 0.16%, or 0.29% at a thickness of 0.70 mm, or a value within a numerical range formed by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or a chemically strengthened glass-ceramic with the required properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or a chemically strengthened glass-ceramic with the required properties of the present application can be obtained.

[0206] In some embodiments of the present application, the b value of the glass-ceramic or chemically strengthened glass-ceramic is < 0.70, preferably ≤ 0.60 at a thickness of 0.70 mm. In the present application, the b value refers to the optical b value measured under D65 light source, and the Konica Minolta CM-3600A is used to measure the b value in the transmittance mode, and the result is shown as b (D65). The smaller the b value, the better the display effect of the glass-ceramic or chemically strengthened glass-ceramic can be ensured. When the b value is large, the glass-ceramic or chemically strengthened glass-ceramic will have an undesirable color, which will result in a display effect that cannot meet the application requirements of the display cover glass.

[0207] In some embodiments, the b value of the glass-ceramic or chemically strengthened glass-ceramic can 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 defined by any two of the above specific values as endpoints, as long as the glass-ceramic or chemically strengthened glass-ceramic having the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the glass-ceramic or chemically strengthened glass-ceramic having the desired properties of the present application can be obtained.

[0208] The glass-ceramic or chemically strengthened glass-ceramic of the present application has high transmittance, low haze and low b value, which all indicate that the optical properties of the glass-ceramic or chemically strengthened glass-ceramic of the present application are excellent and have good uniformity, and the glass-ceramic or chemically strengthened glass-ceramic is in a transparent state, which can meet the application requirements of the display cover glass of electronic devices.

[0209] In some embodiments of the present application, the Young's modulus of the glass-ceramic or chemically strengthened glass-ceramic is ≥ 100 GPa, preferably the Young's modulus of the glass-ceramic or chemically strengthened glass-ceramic is 105 GPa to 112.50 GPa. By making the Young's modulus of the glass-ceramic or chemically strengthened glass-ceramic not less than 100 GPa, the high network structure strength of the glass-ceramic or chemically strengthened glass-ceramic can be ensured, the stress relaxation effect of the chemically strengthened glass-ceramic during ion exchange can be reduced, and the weakening effect of high temperature and long time factors on the deep stress in the compound compressive stress during ion exchange can be slowed down.

[0210] In some embodiments, the Young's modulus of the glass-ceramic or the chemically strengthened glass-ceramic can 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 a value within a range defined by any two of the above specific values as endpoints, as long as a glass-ceramic or a chemically strengthened glass-ceramic with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or a chemically strengthened glass-ceramic with desired properties of the present application can be obtained.

[0211] In some embodiments of the present application, the Vickers hardness of the glass-ceramic or the chemically strengthened glass-ceramic is ≥ 650 kgf / mm 2 , preferably, the Vickers hardness of the glass-ceramic or the chemically strengthened glass-ceramic is 650 kgf / mm 2 ~ 800 kgf / mm 2 . The Vickers hardness of the glass-ceramic or the chemically strengthened glass-ceramic within the above range indicates that the glass-ceramic or the chemically strengthened glass-ceramic has high hardness and high intrinsic strength, thereby ensuring excellent mechanical properties.

[0212] In some embodiments of the present application, the Vickers hardness of the glass-ceramic or the chemically strengthened glass-ceramic can be 650 kgf / mm 2 , 654 kgf / mm 2 , 653 kgf / mm 2 , 658 kgf / mm 2 , 659 kgf / mm 2 , or 660 kgf / mm 2 , or a value within a range defined by any two of the above specific values as endpoints, as long as a glass-ceramic or a chemically strengthened glass-ceramic with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or a chemically strengthened glass-ceramic with desired properties of the present application can be obtained.

[0213] In some embodiments of the present application, the chemically strengthened glass-ceramic is subjected to high temperature and high humidity failure test at a temperature of 85°C and a relative humidity of 85%, and the high temperature and high humidity failure time of the chemically strengthened glass-ceramic is ≥ 240 h, wherein the high temperature and high humidity failure time is the total time from the start of the high temperature and high humidity test to the appearance of spots or whitish marks on the chemically strengthened glass-ceramic that cannot be wiped off.

[0214] The thickness of the glass-ceramic or chemically strengthened glass-ceramic can be selected by those skilled in the art according to requirements. In some embodiments of the present application, the thickness of the glass-ceramic or chemically strengthened glass-ceramic is 0.3 mm to 2 mm, preferably 0.45 mm to 0.8 mm. Exemplarily, the thickness of the glass-ceramic or chemically strengthened glass-ceramic can be 0.3 mm to 1.5 mm, 0.3 mm to 1.00 mm, or 0.40 to 0.80 mm.

[0215] In some embodiments of the present application, the glass-ceramic or chemically strengthened glass-ceramic is planar or curved.

[0216] After the foregoing introduction of the composition, crystal phase structure and stress structure of the chemically strengthened glass-ceramic, the preparation method of the chemically strengthened glass-ceramic will be specifically introduced below.

[0217] In the present application, the preparation process of the chemically strengthened glass-ceramic mainly includes the preparation process of the glass-ceramic and the chemical strengthening process, and the preparation process of the glass-ceramic mainly includes the preparation process of the base glass and the heat treatment process of the base glass.

[0218] In the present application, the base glass can be prepared by using the forming method in the prior art, and the present application does not have any limitation thereon. For example, the forming method of the base glass can include but is not limited to float method, overflow method, calendering or casting process. Exemplarily, the components are mixed according to the formula, and after melting and forming, cooling and annealing treatment are performed, and the base glass can be obtained.

[0219] Exemplarily, the raw materials (industrial conventional raw materials) are prepared according to the formula, a refining agent is added, and then the mixture is mixed for a period of time to obtain a raw material mixture with uniform mixture. The raw material mixture is placed in a platinum crucible, heated to 1250°C to 1680°C, and preferably the melting temperature is 1480°C to 1680°C, and preferably the temperature is maintained for 3 to 12 hours, and then poured into a forming mold for cooling and forming. Preferably, after cooling to 750°C to 1000°C, the base glass is placed in an annealing furnace for annealing treatment, and the annealing temperature is preferably 400°C to 650°C, and the annealing time is preferably 10 to 48 hours. After that, the base glass is cooled to room temperature in the furnace, and the base glass can be obtained. Those skilled in the art can select the type and amount of the refining agent according to requirements, and no creative labor is required. Further, the refining agent can include but is not limited to one or more of sodium chloride, tin oxide, antimony oxide or arsenic oxide, and the addition amount of the refining agent can be 0wt% to 1wt% of the total amount of the raw materials.

[0220] In some embodiments of the present application, the heat treatment process of the substrate glass can comprise a nucleation treatment and / or a crystallization treatment, preferably both a nucleation treatment and a crystallization treatment. In some embodiments, the crystallization treatment comprises a one-step crystallization treatment or a two-step crystallization treatment. In some embodiments, a two-step crystallization treatment can be used for preparing a curved microcrystalline glass, and when a two-step crystallization treatment is used, the second step of the crystallization treatment is to place the crystallized glass material obtained from the first step of the crystallization treatment into a hot bending mold, heat to the crystallization temperature and perform a 3D hot bending forming treatment.

[0221] In some embodiments of the present application, in order to obtain the desired physical and chemical properties of the microcrystalline glass, the heat treatment of the substrate glass can be performed in one step or in two or more steps. If the heat treatment is performed in one step, it means that the nucleation treatment (i.e., the nucleation treatment) is not performed separately, but a one-step heating is directly performed, and the nucleation and the growth of the target crystals are performed at the temperature reached in the one-step heating process, which can be understood as directly performing the crystallization treatment. If the heat treatment is performed in two steps, it means that a two-step heating process is performed, and the nucleation treatment (i.e., the nucleation treatment) is performed first, and then the growth of the target crystals (i.e., the crystallization treatment) is performed.

[0222] In order to make the microcrystalline glass precipitate the desired crystal phase and obtain the desired physical and chemical properties, further, the temperature of the nucleation treatment can be 530-600°C, the time of the nucleation treatment can be 0-24h, preferably 2-8h; the temperature of the crystallization treatment can be 700-750°C, the time of the crystallization treatment can be 0.10-24h, preferably 1-3h. When performing the heat treatment, the heating rate is preferably controlled to be 5-15°C / min, more preferably the heating rate is 10°C / min. The temperature of the nucleation treatment refers to the temperature at which the crystal nucleus can form. The temperature of the crystallization treatment refers to the temperature at which the target crystals can grow controllably.

[0223] After the heat treatment, the person skilled in the art can also perform other conventional steps to obtain the microcrystalline glass sample that meets the required specifications or requirements, for example, the steps of shaping, cutting (such as using a multi-wire cutting machine), CNC machining (computer numerical control), thinning or polishing can be performed.

[0224] In some embodiments of the present application, the chemical strengthening microcrystalline glass that meets the desired performance can be prepared by performing a specific chemical strengthening treatment on the aforementioned microcrystalline glass.

[0225] In the present application, the chemical strengthening treatment, i.e. ion exchange method, is to immerse the glass-ceramics in a molten salt bath to exchange the alkali metal ions with smaller ionic radius in the glass-ceramics with the alkali metal ions with larger ionic radius in the molten salt bath, thereby forming a compressive stress layer on the surface of the glass-ceramics to obtain the glass-ceramics with better mechanical properties.

[0226] In some embodiments of the present application, the chemical strengthening treatment can be a single-step strengthening method or a multi-step strengthening method. The molten salt bath used in the chemical strengthening treatment is a molten salt bath containing sodium salt and / or potassium salt. Preferably, the molten salt bath used in the chemical strengthening treatment of the present application is a mixed molten salt bath containing sodium salt and potassium salt, and the temperature of the molten salt bath is preferably 380-500°C, more preferably 380-470°C. In some embodiments of the present application, the concentration of potassium salt in the salt bath is preferably 0-90wt%, and the concentration of sodium salt is 10-100wt%, more preferably a certain amount (e.g. 0-0.5wt%) of lithium salt is added to the salt bath. In some embodiments of the present application, the concentration of potassium salt in the salt bath is preferably 20-90wt%, and the concentration of sodium salt is 10-80wt%, more preferably 0.1-0.5wt% of lithium salt is added to the salt bath. In some embodiments of the present application, the time for the chemical strengthening treatment is preferably 0.1-6h, preferably 0.1-3h. The sodium salt can be selected from at least one of sodium nitrate, sodium sulfate and sodium carbonate, preferably sodium nitrate; the potassium salt can be selected from at least one of potassium nitrate, potassium sulfate and potassium carbonate, preferably potassium nitrate; and the lithium salt can be selected from at least one of lithium nitrate, lithium sulfate and lithium carbonate, preferably lithium nitrate.

[0227] The glass-ceramics or chemically strengthened glass-ceramics provided by the present application have excellent properties and can be used in electronic devices, including but not limited to mobile phones, tablet computers, handheld game consoles, portable digital devices (e.g. digital cameras), vehicle center control, electronic whiteboard glass, smart home, smart wear (e.g. smart bracelet, smart watch, smart glasses), vehicles, aircraft or vessels, and any desired glass-ceramic glassware. For example, it can be used in the display screen, cover glass, touch screen, inner screen or inner frame of an electronic device; for example, it can be used in the windshield, such as the front windshield or side windshield, of a vehicle, aircraft or vessel. For example, it can be used in a workbench, other surfaces, appliance doors, floor tiles, wall panels or storage containers. Other surfaces can include but are not limited to exterior wall surfaces, stair tread surfaces, column facings or counter surfaces, and storage containers can include but are not limited to cups, plates, medicine bottles or beverage bottles.

[0228] Exemplarily, the microcrystalline glass or chemically strengthened microcrystalline glass with excellent performance provided by the present application can be used to manufacture a glass device. The glass device referred to herein can be regular or irregular, and a person skilled in the art can manufacture it according to requirements.

[0229] Exemplarily, the microcrystalline glass or chemically strengthened microcrystalline glass with excellent performance provided by the present application can be used to manufacture a cover glass, which can be a display screen cover, a back cover or a camera protection cover of an electronic device. Exemplarily, the microcrystalline glass or chemically strengthened microcrystalline glass with excellent performance provided by the present application can be used in an electronic device. Referring to Figure 4 、 Figure 5 and Figure 6 , in some embodiments of the present application, an electronic device is provided, which can be a mobile phone, a tablet computer, a smart wearable device or the like, and the electronic device comprises a housing 1 assembled on the outer side of the electronic device, the housing 1 comprises a display screen cover 11 assembled on the front side and a back cover 12 assembled on the back side, and the display screen cover 11 covers the display module 4, wherein the display screen cover 11 and / or the back cover 12 are made of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass. In the present application, the display screen cover 11 and the back cover 12 can be made of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass entirely or partially. In the present application, the display screen can be a touch display screen, and the display screen cover 11 can be a protection cover plate arranged on the touch display screen. In the present application, the back cover 12 can cover only the back side (and the side away from the display screen) of the electronic device, or can cover the back side and the side frame of the electronic device, and optionally, the back cover 12 can cover all the side frames of the electronic device or can cover part of the side frames.

[0230] In some embodiments of the present application, as shown in Figure 5 , the electronic device further comprises a camera assembly 2 located inside the housing 1, and the housing 1 can comprise a camera protection cover plate 13, which covers the camera assembly 2 for protecting the camera assembly 2, and the camera protection cover plate 13 is made of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass. In the present application, the camera protection cover plate 13 can be made of the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass partially or entirely. In the present application, the camera protection cover plate 13 can be located on the front side of the electronic device or on the back side of the electronic device according to the location of the camera assembly 2. In some embodiments of the present application, the camera protection cover plate 13 can be in a separate structure from the display screen cover 11 or the back cover 12. In another embodiment of the present application, the camera protection cover plate 13 can be in an integrated structure with the display screen cover 11 or the back cover 12.

[0231] As shown in some embodiments of the present application, the electronic device further comprises a middle frame 3 between the display module 4 and the shell 1, and the middle frame 3 can comprise the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass. Figure 6

[0232] In the embodiments of the present application, the display screen cover plate, the back cover, the camera protection cover plate, and the middle frame in the electronic device can be any one of the four using the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass, or any two of them using the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass, or all three of them using the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass, or all four of them using the aforementioned microcrystalline glass or chemically strengthened microcrystalline glass.

[0233] The technical solutions of the present application are further described in detail below in combination with embodiments. The embodiments of the present application described in detail below are exemplary and are only used to explain the present application and cannot be understood as a limitation of the present application.

[0234] Embodiment 1

[0235] (1) Preparation of base glass:

[0236] According to the proportion of each component in Table 1, each raw material (industrial conventional raw material) is configured, the total mass of the configured raw material is 1000g, 5g of clarifying agent sodium chloride (NaCl) is added to the configured raw material, and then the V-shaped mixer is mixed for 30 minutes to obtain a uniformly mixed raw material mixture.

[0237] The raw material mixture is transferred to a platinum crucible, then melted in the platinum crucible at 1650℃ for 5 hours, then poured into a forming mold for cooling, cooled to 900℃, then placed in a 500℃ annealing furnace for annealing for 24 hours, then cooled to room temperature with the furnace, and the base glass brick is obtained.

[0238] (2) Preparation of microcrystalline glass: according to the heat treatment process in Table 2, the base glass brick is placed in an annealing furnace, heated from room temperature to 550℃ at a rate of 10℃ / min for nucleation treatment, then heated to 710℃ at a rate of 10℃ / min for crystallization treatment, and then cooled to room temperature at a rate of 1℃ / min. The microcrystalline glass sample brick is obtained. The composition of the prepared microcrystalline glass is the same as that of the base glass, and the details are shown in Table 1.

[0239] ​The obtained glass-ceramic sample bricks are subjected to cold processing of cutting, CNC machining (the CNC instrument used in the present application is of RCG500S type), and polishing in sequence, and a glass-ceramic sample meeting the required specifications and requirements can be prepared. In Examples 1-7 and Comparative Examples 1-6 of the present application, the glass-ceramic sample bricks are subjected to the aforementioned cold processing to prepare glass-ceramic samples with a thickness of 0.70 mm, specifically, glass-ceramic polished sheet samples with a size of 50 mm x 50 mm x 0.70 mm or 157.79 mm x 73.82 mm x 0.70 mm.

[0240] Test conditions for the glass-ceramic sample obtained in Example 1:

[0241] The crystalline phase composition, crystallinity, average grain size, Vickers hardness, Young's modulus of the glass-ceramic sample, and the optical b value, haze, and transmittance (under 550 nm wavelength light) of the glass-ceramic sample with a thickness of 0.70 mm are tested respectively, and the results are shown in Table 2.

[0242] (3) Preparation of chemically strengthened glass-ceramic: The obtained glass-ceramic sample is placed in a strengthening furnace cavity and preheated for 5 min according to the chemical strengthening process in Table 3, and then quickly placed in a 460℃ molten salt bath for chemical strengthening treatment. The composition of the molten salt is 90wt% KNO3+10wt% NaNO3+0.15wt% LiNO3. Here, "0.15wt% LiNO3" means that 0.15wt% LiNO3 is added based on the total mass of KNO3 and NaNO3, and other similar expressions have similar meanings. After 3h of chemical strengthening treatment, the glass-ceramic sample is taken out and slowly cooled to room temperature on the furnace body of the strengthening furnace, and then the salt on the surface of the glass-ceramic is washed off with clean water. After drying the glass-ceramic sample, the chemically strengthened glass-ceramic is obtained.

[0243] Test conditions for the chemically strengthened glass-ceramic obtained in Example 1:

[0244] I. The DOL_0, CS_50, and |CT_AV| of the chemically strengthened glass-ceramic are measured under SLP-2000 stress instrument (the light source wavelength used is 518 nm, SOC=26 (nm / cm) / MPa, the refractive index is set to 1.56, and the exposure time is 300 μsec). The CT_LD value is calculated, and the results are shown in Table 3.

[0245] II. The surface Na2O mass percentage of the chemically strengthened glass-ceramic and the surface K2O mass percentage of the chemically strengthened glass-ceramic are measured by XRF, and the results are shown in Table 3. The values of formulas N and Y are calculated.

[0246] III. The average sandpaper drop height of the chemically strengthened glass-ceramics was tested, and the high temperature and high humidity test was performed on the chemically strengthened glass-ceramics, and the results are shown in Table 3.

[0247] Examples 2-7

[0248] Each of the examples was performed with reference to Example 1, except that the raw material composition, different process parameters and the corresponding test results of each example are shown in Tables 1-3.

[0249] The XRD pattern of the glass-ceramics of Example 1 is shown in Figure 1 From the figure, it can be seen that the main crystal phase in the glass-ceramics is lithium disilicate crystal phase.

[0250] The comparison chart of the transmittance curves of the glass-ceramics of Example 1 and the chemically strengthened glass-ceramics is shown in Figure 2 From the figure, it can be seen that both the glass-ceramics and the chemically strengthened glass-ceramics prepared therefrom are transparent in the visible light range, both have high transmittance, and the transmittance remains basically unchanged before and after chemical strengthening.

[0251] The comparison chart of the XRD patterns of the glass-ceramics of Example 1 and the chemically strengthened glass-ceramics is shown in Figure 3 From the figure, it can be seen that the crystal phase structure of the glass-ceramics does not change significantly before and after chemical strengthening, and the main crystal phase of the chemically strengthened glass-ceramics prepared from the glass-ceramics is also lithium disilicate crystal phase.

[0252] Comparative Examples 1-6

[0253] Each of the comparative examples was performed with reference to Example 1, except that the raw material composition, different process parameters and the corresponding test results of each comparative example are shown in Tables 1-3.

[0254] The physical pictures of the chemically strengthened glass-ceramics provided by Examples 1-3 and Comparative Examples 1-2 before and after the high temperature and high humidity test are shown in Figures 7 to 11 In order to show the state of the chemically strengthened glass-ceramic sheet, the photograph was taken on a black background paper. From the comparison of the physical comparison chart, it can be seen that by meeting the specific relationship requirements between the mass percentages of Na2O and K2O on the surface of the chemically strengthened glass-ceramics and CT_LD, the present application can ensure that the chemically strengthened glass-ceramics has better high temperature and high humidity resistance while meeting the high stress level, indicating that it has better weather resistance.

[0255]

[0256]

[0257]

[0258]

[0259] From the above examples and comparative examples of Table 1-Table 3, for the same microcrystalline glass, by making the chemical strengthening microcrystalline glass meet the requirements of the relationship N of the present application, i.e. by making the surface Na2O mass percentage of the chemical strengthening microcrystalline glass, the surface K2O mass percentage of the chemical strengthening microcrystalline glass and the CT_LD satisfy a specific relationship, it can be ensured that the chemical strengthening microcrystalline glass has excellent stress level and excellent high temperature and high humidity resistance, and further can make the obtained chemical strengthening microcrystalline glass have higher mechanical strength performance and good weather resistance.

[0260] In the schemes of Comparative Example 1-Comparative Example 6, the surface Na2O mass percentage of the chemical strengthening microcrystalline glass and the surface K2O mass percentage of the chemical strengthening microcrystalline glass and the CT_LD do not satisfy the specific relationship, finally, the prepared chemical strengthening microcrystalline glass either has spots or whitening marks that cannot be wiped off in the high temperature and high humidity test, and the weather resistance obviously does not meet the application requirements, or the stress level is low and the anti-drop damage performance is poor.

[0261] The above is only a specific embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A chemically strengthened microcrystalline glass characterized in that, The chemical strengthening microcrystalline glass contains lithium disilicate crystal phase, wherein the mass percentage of the lithium disilicate crystal phase is greater than that of other crystal phases present in the chemical strengthening microcrystalline glass, and the mass percentage of the lithium disilicate crystal phase accounts for more than 70% of all crystal phases of the chemical strengthening microcrystalline glass; the chemical strengthening microcrystalline glass has a compressive stress layer on the surface and a tensile stress in the interior; the chemical strengthening microcrystalline glass satisfies: N = n * (CT_LD-50000) / 10000, -32.5 < N < 15, N is an index related to mechanical strength and weather resistance, Wherein, n=(surface Na2O mass percentage of the chemically strengthened glass-ceramics / surface K2O mass percentage of the chemically strengthened glass-ceramics) 2 The surface Na2O mass percentage of the chemically strengthened glass-ceramics and the surface K2O mass percentage of the chemically strengthened glass-ceramics are determined by XRF; CT_LD is the tensile stress linear density, with the unit of MPa / mm, Wherein, t is the thickness of the chemically strengthened glass-ceramics, with the unit of mm; DOL_0 is the depth of the compressive stress layer of the chemically strengthened glass-ceramics, with the unit of μm; |CT_AV| is the absolute value of the average tensile stress of the chemically strengthened glass-ceramics, with the unit of MPa, the formula N is calculated by substituting the data into the above unit, and the calculation result is obtained, and the unit does not participate in the calculation; The surface Na2O mass percentage of the chemical strengthening microcrystalline glass is 5% to 8.5% in terms of mass percentage of oxides as measured by XRF.

2. The chemically strengthened glass ceramic according to claim 1, wherein -28.0≤N≤0。 3. The chemically strengthened glass ceramic according to claim 2, wherein -20.0≤N≤-2.5。 4. The chemically strengthened glass ceramic of claim 1, wherein, The chemical strengthening microcrystalline glass satisfies: 45000 MPa / mm ≤ CT_LD ≤ 52000 MPa / mm.

5. The chemically strengthened glass ceramic according to claim 4, wherein 45900 MPa / mm ≤ CT_LD ≤ 50000 MPa / mm.

6. The chemically strengthened glass ceramic according to claim 5, wherein 47500 MPa / mm ≤ CT_LD ≤ 50000 MPa / mm.

7. The chemically strengthened glass ceramic according to claim 4, wherein The value of the formula 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.

8. The chemically strengthened glass ceramic of claim 1, wherein, The surface K2O mass percentage of the chemical strengthening microcrystalline glass is 0.7% to 2.0% in terms of mass percentage of oxides as measured by XRF; and / or, The mass percentage of Na2O in the composition at the center of the chemical strengthening microcrystalline glass is 3% to 3.5% in terms of mass percentage of oxides.

9. The chemically strengthened glass ceramic according to claim 8, wherein, The surface Na2O mass percentage of the chemical strengthening microcrystalline glass is 5.5% to 7.5% in terms of mass percentage of oxides as measured by XRF; and / or, The surface K2O mass percentage of the chemical strengthening microcrystalline glass is 0.7% to 1.5% in terms of mass percentage of oxides as measured by XRF; and / or, The mass percentage of Na2O in the composition at the center of the chemical strengthening microcrystalline glass is 3.1% to 3.2% in terms of mass percentage of oxides.

10. The chemically strengthened glass ceramic according to claim 4, wherein The surface K2O mass percentage of the chemical strengthening microcrystalline glass is 0.7% to 2.0% in terms of mass percentage of oxides as measured by XRF; and / or, The mass percentage of Na2O in the composition at the center of the chemical strengthening microcrystalline glass is 3% to 3.5% in terms of mass percentage of oxides.

11. The chemically strengthened glass ceramic according to claim 8, wherein The surface Na2O mass percentage of the chemical strengthening microcrystalline glass is 5.30%, 6.12%, 7.00%, 5.21%, 6.32%, 5.17% or 6.36% in terms of mass percentage of oxides as measured by XRF; and / or, The surface K2O mass percentage of the chemically strengthened glass-ceramics is 1.25%, 0.81%, 0.77%, 1.24%, 0.80% or 1.26% as measured by XRF in mass percentage of oxides; and / or, The mass percentage of Na2O in the composition at the center of the chemically strengthened glass-ceramics is 3.16% or 3.14% as measured by XRF in mass percentage of oxides.

12. The chemically strengthened glass ceramic of claim 1, wherein, The chemically strengthened glass-ceramics satisfies: Y = ΔC x ((CT_LD - 50000) / 100) 2 Y < 60, said Y being a stress-related index, wherein ΔC is the difference between the surface Na2O mass percentage of the chemically strengthened glass-ceramics and the Na2O mass percentage at the center of the chemically strengthened glass-ceramics, the surface Na2O mass percentage of the chemically strengthened glass-ceramics is measured by XRF; CT_LD is the tensile stress linear density, in MPa / mm, in formula Y, is calculated by substituting the data into the formula with the above unit requirements, and the unit does not participate in the calculation.

13. The chemically strengthened glass ceramic according to claim 12, wherein, Y≤50。 14. The chemically strengthened glass ceramic according to claim 13, wherein, Y≤20。 15. The chemically strengthened glass ceramic of claim 10, wherein, The chemically strengthened glass-ceramics satisfies: Y = ΔC x ((CT_LD - 50000) / 100) 2 Y < 60, said Y being a stress-related index, wherein ΔC is the difference between the surface Na2O mass percentage of the chemically strengthened glass-ceramics and the Na2O mass percentage at the center of the chemically strengthened glass-ceramics, the surface Na2O mass percentage of the chemically strengthened glass-ceramics is measured by XRF; CT_LD is the tensile stress linear density, in MPa / mm, in formula Y, is calculated by substituting the data into the formula with the above unit requirements, and the unit does not participate in the calculation.

16. The chemically strengthened glass ceramic of claim 12, wherein, The value of formula Y is 0.36, 10.14, 11.58, 11.88, 13.02, 13.25 or 14.

84.

17. The chemically strengthened glass ceramic of claim 1, wherein, The chemically strengthened glass-ceramics satisfies: 75MPa≤|CT_AV|≤120 MPa, wherein |CT_AV| is the absolute value of the average tensile stress; and / or, DOL_0 is 0.18t-0.25t, wherein DOL_0 is the depth of the compressive stress layer, and t is the thickness of the chemically strengthened glass-ceramics; and / or CS_50 is 150MPa~250MPa, wherein CS_50 refers to the compressive stress value at a depth of 50μm from the main surface of the chemically strengthened glass-ceramics.

18. The chemically strengthened glass ceramic according to claim 17, wherein, The chemically strengthened glass-ceramics satisfies: 77MPa≤|CT_AV|≤90 MPa, wherein |CT_AV| is the absolute value of the average tensile stress; and / or, 0.20t-0.25t, wherein DOL_0 is the depth of the compressive stress layer, and t is the thickness of the chemically strengthened glass-ceramics; and / or CS_50 is 160MPa~180MPa, wherein CS_50 refers to the compressive stress value at a depth of 50μm from the main surface of the chemically strengthened glass-ceramics.

19. The chemically strengthened glass ceramic of claim 15, wherein, The chemically strengthened glass-ceramics satisfies: 75MPa≤|CT_AV|≤120 MPa, wherein |CT_AV| is the absolute value of the average tensile stress; and / or, DOL_0 is 0.18t-0.25t, wherein DOL_0 is the depth of the compressive stress layer, and t is the thickness of the chemically strengthened glass-ceramics; and / or CS_50 is 150MPa~250MPa, wherein CS_50 refers to the compressive stress value at a depth of 50μm from the main surface of the chemically strengthened glass-ceramics.

20. The chemically strengthened glass ceramic of any one of claims 1 to 19, wherein, The composition of the chemically strengthened glass-ceramics at the center or the tensile stress layer comprises, in terms of mole percentage of oxides, 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%.

21. The chemically strengthened glass ceramic according to claim 20, wherein, The composition of the chemically strengthened glass-ceramics at the center or the tensile stress layer comprises, in terms of mole percentage of oxides, the mole percentage of SiO2 is 61.50% to 63.30%; and / or, the mole percentage of P2O5 is 1.20% to 1.91%; and / or, the mole percentage of Na2O is 1.85% to 3.05%; and / or, the mole percentage of B2O3 is 0 to 0.65%; and / or, the mole percentage of ZrO2 is 4.20% to 4.60%; and / or, the mole percentage of Li2O is 25.52% to 26.52%.

22. The chemically strengthened glass ceramic of claim 20, wherein, The composition of the chemically strengthened glass-ceramics at the center or the tensile stress layer comprises, in terms of mole percentage of oxides, the mole percentage of SiO2 is 62.00% to 62.60%; and / or, the mole percentage of P2O5 is 1.30% to 1.60%; and / or, the mole percentage of Na2O is 2.20% to 3.00%; and / or, the mole percentage of Li2O is 25.52% to 26.00%.

23. The chemically strengthened glass ceramic of claim 20, wherein, In the composition of the chemically strengthened glass-ceramics at the center or the tensile stress layer, the mole percentage of Na2O [Na2O], the mole percentage of B2O3 [B2O3], and the mole percentage of ZrO2 [ZrO2] satisfy the following relationship: Z = -1.344 x (2.65 - 100 x [Na20]) 2 + 0.466 x 100 x [B203] + 1.203 x 100 x [Zr02], 4.80 < Z < 5.35; and / or, In the composition of the chemically strengthened glass-ceramics at the center or the tensile stress layer, the mole percentage of Na2O [Na2O] and the mole percentage of B2O3 [B2O3] satisfy the following relationship: 0.90%≤[Na2O]-[B2O3]≤3.10%; and / or, In the composition of the chemically strengthened glass-ceramics at the center or the tensile stress layer, the mole percentage of Na2O [Na2O] and the mole percentage of Li2O [Li2O] satisfy the following relationship: 8.55≤[Li2O] / [Na2O]≤13.

85.

24. The chemically strengthened glass ceramic of claim 20, wherein, In the composition of the chemically strengthened glass-ceramics at the center or the tensile stress layer, the mole percentage of Na2O [Na2O], the mole percentage of B2O3 [B2O3], and the mole percentage of ZrO2 [ZrO2] satisfy the following relationship: Z = -1.344 x (2.65 - 100 x [Na20]) 2 + 0.466 x 100 x [B203] + 1.203 x 100 x [Zr02], 5.05 < Z < 5.25; and / or, In the composition of the chemically strengthened glass-ceramics at the center or the tensile stress layer, the mole percentage of Na2O [Na2O] and the mole percentage of B2O3 [B2O3] satisfy the following relationship: 2.00%≤[Na2O]-[B2O3]≤3.00%; and / or, The molar percentage of Na2O [Na2O] and the molar percentage of Li2O [Li2O] in the composition of the center or the tensile stress layer of the chemically strengthened glass-ceramics satisfy the following relationship: 8.60≤[Li2O] / [Na2O]≤11.

00.

25. The chemically strengthened glass ceramic of claim 20, wherein, The molar percentage of Na2O [Na2O] and the molar percentage of B2O3 [B2O3] in the composition of the center or the tensile stress layer of the chemically strengthened glass-ceramics satisfy the following relationship: 2.30%≤[Na2O]-[B2O3]≤3.00%.

26. The chemically strengthened glass ceramic of claim 23, wherein, The composition of the center or the tensile stress layer of the chemically strengthened glass-ceramics satisfies: The value of Z is 5.10, 5.09 or 5.12; and / or, The value of [Na2O]-[B2O3] is 2.36%, 2.93% or 2.96%; and / or, The value of [Li2O] / [Na2O] is 10.92, 8.84 or 8.

69.

27. The chemically strengthened glass ceramic of claim 1, wherein, The mass of the lithium disilicate crystal phase accounts for more than 85% of all crystal phases of the chemically strengthened glass-ceramics.

28. The chemically strengthened glass ceramic of any of claims 1-19, wherein, The average grain size of the chemically strengthened glass-ceramics is 40 nm or less; and / or, The crystallinity of the chemically strengthened glass-ceramics is 45% or more.

29. The chemically strengthened glass ceramic of claim 28, wherein, The average grain size of the chemically strengthened glass-ceramics is 15 nm to 35 nm; and / or, The crystallinity of the chemically strengthened glass-ceramics is 45% to 85%.

30. The chemically strengthened glass ceramic of claim 28, wherein, The crystallinity of the chemically strengthened glass-ceramics is 55% to 65%.

31. The chemically strengthened glass ceramic of claim 20, wherein, The average grain size of the chemically strengthened glass-ceramics is 40 nm or less; and / or, The crystallinity of the chemically strengthened glass-ceramics is 45% or more.

32. The chemically strengthened glass ceramic of claim 23, wherein The average grain size of the chemically strengthened glass-ceramics is 40 nm or less; and / or, The crystallinity of the chemically strengthened glass-ceramics is 45% or more.

33. The chemically strengthened glass ceramic of claim 1, wherein, The chemically strengthened glass-ceramics is transparent in the visible light wavelength range; and / or, The haze of the chemically strengthened glass-ceramics is <0.30% at a thickness of 0.70 mm, and / or, The b value of the chemically strengthened glass-ceramics is <0.70 at a thickness of 0.70 mm, the b value referring to the optical b value measured under D65 light source.

34. The chemically strengthened glass ceramic of claim 33, wherein, The transmittance of the chemically strengthened glass-ceramics is ≥90.00% for light of 550 nm wavelength at a thickness of 0.70 mm; and / or, The haze of the chemically strengthened glass-ceramics is <0.20% at a thickness of 0.70 mm, and / or, The b value of the chemically strengthened glass-ceramics is ≤0.60 at a thickness of 0.70 mm.

35. The chemically strengthened glass ceramic of claim 34, wherein, The transmittance of the chemically strengthened glass-ceramics is >90.40% for light of 550 nm wavelength at a thickness of 0.70 mm.

36. The chemically strengthened glass ceramic of claim 32, wherein, The chemically strengthened glass-ceramics is transparent in the visible light wavelength range; and / or, The haze of the chemically strengthened glass-ceramics is <0.30% at a thickness of 0.70 mm, and / or, The b value of the chemically strengthened glass-ceramics is <0.70 at a thickness of 0.70 mm, the b value referring to the optical b value measured under D65 light source.

37. The chemically strengthened glass ceramic of claim 1, wherein, The Young's modulus of the chemically strengthened glass-ceramics is ≥100 GPa; and / or The Young's modulus of the chemically strengthened glass-ceramics is ≥100 GPa; and / or The chemical strengthening microcrystalline glass has a Vickers hardness ≥ 650 kgf / mm 2 .

38. The chemically strengthened glass ceramic of claim 37, wherein, The Young's modulus of the chemically strengthened glass-ceramics is 105 GPa to 112.50 GPa; and / or The chemical strengthening microcrystalline glass has a Vickers hardness of 650 kgf / mm 2 800 kgf / mm 2 .

39. The chemically strengthened glass ceramic of claim 36, wherein, The Young's modulus of the chemically strengthened glass-ceramics is ≥ 100 GPa; and / or The chemical strengthening microcrystalline glass has a Vickers hardness ≥ 650 kgf / mm 2 .

40. The chemically strengthened glass ceramic of claim 1, wherein The chemically strengthened glass-ceramics is planar or curved; and / or, the thickness of the chemically strengthened glass-ceramics is 0.3 mm to 2 mm; and / or, the chemically strengthened glass-ceramics does not contain a petalite crystal phase.

41. The chemically strengthened glass ceramic of claim 40, wherein, The thickness of the chemically strengthened glass-ceramics is 0.45 mm to 0.8 mm.

42. The chemically strengthened glass ceramic of claim 39, wherein, The chemically strengthened glass-ceramics is planar or curved; and / or, the thickness of the chemically strengthened glass-ceramics is 0.3 mm to 2 mm; and / or, the chemically strengthened glass-ceramics does not contain a petalite crystal phase.

43. The chemically strengthened glass ceramic of any one of claims 1-42, wherein, The chemically strengthened glass-ceramics is subjected to high-temperature and high-humidity failure test at a temperature of 85°C and a relative humidity of 85%, and the high-temperature and high-humidity failure time of the chemically strengthened glass-ceramics is ≥ 240 h, wherein the high-temperature and high-humidity failure time is the total time length from the start of the high-temperature and high-humidity test to the appearance of spots or whitish marks that cannot be wiped off in the chemically strengthened glass-ceramics.

44. A cover glass, characterized by The cover glass is made of the chemically strengthened glass-ceramics according to any one of claims 1 to 43.

45. An electronic device, comprising: The electronic device comprises the chemically strengthened glass-ceramics according to any one of claims 1 to 43.

46. The electronic device of claim 45, wherein, The electronic device comprises a housing assembled on the outer side of the electronic device, and the housing comprises the chemically strengthened glass-ceramics according to any one of claims 1 to 43.

47. The electronic device of claim 46, wherein, The housing comprises a display screen cover plate assembled on the front side of the electronic device, and the display screen cover plate comprises the chemically strengthened glass-ceramics according to any one of claims 1 to 43.

48. The electronic device of claim 46, wherein, The housing comprises a rear cover assembled on the rear side of the electronic device, and the rear cover comprises the chemically strengthened glass-ceramics according to any one of claims 1 to 43.

49. The electronic device of claim 46, wherein, The electronic device further comprises a camera assembly located inside the housing, and the housing comprises a camera protection cover plate covering the camera assembly, and the camera protection cover plate comprises the chemically strengthened glass-ceramics according to any one of claims 1 to 43.

50. The electronic device of claim 45, wherein, The electronic device further comprises a middle frame, and the middle frame comprises the chemically strengthened glass-ceramics according to any one of claims 1 to 43.

51. A glass article, characterized by, The glass device comprises the chemically strengthened glass-ceramics according to any one of claims 1 to 43.

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