3D curved surface microcrystalline glass, and chemically strengthened microcrystalline glass, preparation method therefor and use thereof

Abstract

3D curved surface microcrystalline glass, and chemically strengthened microcrystalline glass, a preparation method therefor and a use thereof. On the basis of the molar percentages of the oxides, the components of the 3D curved surface microcrystalline glass satisfy the following: 0.180≤5×P2O5 / (Li2O+0.5Al2O3)≤0.250; 18.200≤Li2O / P2O5≤25.500; 0.100≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.200; 1.500≤10×(ZrO2+P2O5) / Li2O≤2.000; and 4.000≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤6.000. The generation of a main crystal phase can be ensured during the mass preparation of the 3D curved surface microcrystalline glass product, and the whole product presents a uniform display effect.

Description

3D curved glass-ceramics, chemically strengthened glass-ceramics, and their preparation and applications

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application No. 202311801461.4, filed with the State Intellectual Property Office of China on December 25, 2023, entitled “3D curved microcrystalline glass, chemically strengthened microcrystalline glass, their preparation method and application”, the entire contents of which are incorporated into this application by reference. Technical Field

[0003] The present application belongs to the field of glass technology, and specifically relates to a 3D curved microcrystalline glass, a chemically strengthened microcrystalline glass, and a preparation method and application thereof. Background Art

[0004] With the development of electronic display technology, glass has gradually replaced plastic materials in display devices as a protective cover material. Simultaneously, with the diversification of electronic product applications, 3D curved screens, such as those in curved mobile phones and smartwatches, are becoming increasingly popular. 3D curved glass-ceramic, in particular, has gradually attracted industry attention due to its superior strength compared to conventional 3D curved glass.

[0005] 3D curved glass-ceramics for display screens, which require high optical display effects, are difficult to mass-produce. This is largely due to the difficulty in ensuring uniform composition and temperature distribution when producing large-scale prefabricated glass-ceramics used to make 3D curved glass-ceramics. This makes it easy for prefabricated glass-ceramics to have localized optical defects. This problem persists even after the prefabricated glass-ceramics are thermally bent, resulting in undesirable localized colors or overall uneven display effects in the resulting 3D curved glass-ceramics. It can even lead to fragmentation during the thermal bending process.

[0006] It should be noted that this part of the content of this application only provides background technology related to this application, and does not necessarily constitute prior art or public knowledge. Summary of the Invention

[0007] In order to increase output, when the production line mass-produces 3D curved microcrystalline glass with a petalite and lithium disilicate crystal phase structure, it generally first produces large-sized substrate glass bricks, such as substrate glass bricks with a length, width and thickness specification of (200mm-500mm)×(100mm-500mm)×(10mm-40mm). The substrate glass bricks are then heat-treated to produce prefabricated microcrystalline glass products. Considering that the microcrystalline glass of this system is usually accompanied by a certain degree of crystallization during the hot bending process, the degree of crystallization of the prefabricated microcrystalline glass products is generally lower than that of the final 3D curved microcrystalline glass products. The prefabricated microcrystalline glass products are then cold-processed to prepare multiple flat microcrystalline glass sheets of the required specifications and sizes. The obtained flat microcrystalline glass sheets are then hot-bent to prepare 3D curved microcrystalline glass products.

[0008] However, the existing microcrystalline glass solutions with petalite and lithium disilicate as the main crystal phases are prone to optical defects in prefabricated microcrystalline glass bricks when they are used for industrial mass production of large-scale prefabricated microcrystalline glass products. This is mainly manifested in that the b-values ​​of different regions in the prefabricated microcrystalline glass bricks vary greatly, and some areas exhibit undesirable colors and are prone to flowery patterns. This difference cannot be improved through subsequent hot bending processes, resulting in large differences in b-values ​​in different regions of the 3D curved microcrystalline glass obtained through hot bending. This in turn affects the overall display effect of the 3D curved microcrystalline glass, making it difficult for the obtained 3D curved microcrystalline glass to meet the application requirements of display cover plates. Some prefabricated microcrystalline glass products even break during the hot bending process, resulting in a decrease in yield.

[0009] The purpose of this application is to overcome the problems existing in the prior art of low mass production yield and easy occurrence of flowery and poor display of 3D curved microcrystalline glass products whose main crystal phases are petalite crystal phase and lithium disilicate crystal phase when mass-producing 3D curved microcrystalline glass products. A 3D curved microcrystalline glass is provided, as well as a preparation method and application thereof.

[0010] In order to achieve the above objectives, the following technical solutions are provided:

[0011] A 3D curved glass-ceramic, wherein the 3D curved glass-ceramic comprises a petalite crystalline phase and a lithium disilicate crystalline phase, wherein the petalite crystalline phase and the lithium disilicate crystalline phase have a higher weight percentage than other crystalline phases present in the 3D curved glass-ceramic;

[0012] Measured in molar percentage of oxides, the composition of the 3D curved glass-ceramics includes:

[0013] SiO2: 60.00mol%-71.00mol%, Al2O3: 1.50mol%-5.00mol%, P2O5: 0.80mol%-1.50mol%, ZrO2: 2.00mol%-4.00mol%, Na2O: 0.00m ol%-1.00mol%, K2O: 0.00mol%-0.50mol%, Li2O: 20.00mol%-30.00mol%, CaO: 0.00mol%-1.60mol%, B2O3: 0.00mol%-1.00mol%;

[0014] The composition of the 3D curved glass-ceramics satisfies the following requirements, expressed in terms of the molar percentage of each oxide in the composition of the 3D curved glass-ceramics:

[0015] 0.180≤5×P2O5 / (Li2O+0.5Al2O3)≤0.250;

[0016] 18.200≤Li2O / P2O5≤25.500;

[0017] 0.100≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.200;

[0018] 1.500≤10×(ZrO2+P2O5) / Li2O≤2.000;

[0019] 4.000≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤6.000. Maintaining the content of each oxide within an appropriate range and combining the oxide content ratio under specific conditions ensures the formation of the primary crystalline phase during the mass production of 3D curved glass-ceramics. This also ensures that the 3D curved glass-ceramics produced overall present a relatively uniform display effect, effectively avoiding the problem of large variations in b-values ​​between different regions of mass-produced 3D curved glass-ceramics, which can lead to poor display effects.

[0020] It should be pointed out that in the above formulas of the present application, the content percentage is substituted into each formula on a molar basis, that is, the molar unit does not participate in the calculation of the formula. For example, if the molar content percentage of P2O5 is 0.80%, 0.80% is substituted into the formula for calculation.

[0021] In some embodiments, the composition of the 3D curved glass-ceramics satisfies the following requirements, expressed in terms of the molar percentage of each oxide in the composition of the 3D curved glass-ceramics:

[0022] 2.600≤99×(CaO+ZrO2) / (Li2O+Na2O+1000K2O)≤5.000;

[0023] 12.200≤(5.6B2O3+10Al2O3+6.5CaO) / ZrO2≤20.000. Further adjusting the content relationship between the various components helps ensure that the 3D curved glass-ceramic achieves excellent optical properties and mechanical strength.

[0024] In some embodiments, the 3D curved glass-ceramics is transparent in the visible light range. By making the 3D curved glass-ceramics transparent in the visible light range, it can meet the requirements of display screens and help broaden the application fields and application scenarios of 3D curved glass-ceramics.

[0025] In some embodiments, the composition of the 3D curved glass-ceramics comprises, in terms of molar percentage of oxides:

[0026] SiO2: 67.50mol%-71.00mol%, Al2O3: 3.50mol%-5.00mol%, P2O5: not less than 0.85mol% and less than 1.50mol%, ZrO2: 2.50mol%-3.50mol%, Na2O: greater than 0.00mol% and not greater than 1.00mol%, K2O: greater than 0.00mol% and not greater than 0.50mol%, Li2O: 20.00mol%-25.00mol%, CaO: greater than 0.50mol% and not greater than 1.50mol%, B2O3: 0.00mol%-1.00mol%. By adjusting the content relationship of the necessary oxides, the network structure of the 3D curved glass-ceramics can be further improved, thereby ensuring the large-scale mass production of prefabricated glass-ceramics and the excellent optical and strength properties of the mass-produced 3D curved glass-ceramics.

[0027] In some embodiments, the 3D curved glass-ceramics does not contain a quartz crystal phase. Preventing the precipitation of a quartz crystal phase in a 3D curved glass-ceramics whose main crystal phases are petalite and lithium disilicate helps ensure the optical performance and overall uniformity of the 3D curved glass-ceramics.

[0028] In some embodiments, the combined content of the petalite and lithium disilicate crystalline phases in the 3D curved glass-ceramics is greater than 60.00 wt%, preferably greater than 70.00 wt%, and more preferably greater than 80.00 wt%, of the mass of the 3D curved glass-ceramics. The average crystal size in the 3D curved glass-ceramics does not exceed 100 nm. A higher content of the main crystalline phase improves the mechanical strength of the 3D curved glass-ceramics. A smaller average crystal size helps ensure the excellent optical properties of the 3D curved glass-ceramics.

[0029] In some embodiments, the composition of the 3D curved glass-ceramics satisfies the following requirements, expressed in terms of the molar percentage of each oxide in the composition of the 3D curved glass-ceramics:

[0030] 0.184≤5×P2O5 / (Li2O+0.5Al2O3)≤0.245; and / or

[0031] 18.200≤Li2O / P2O5≤25.000; and / or

[0032] 0.190≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.180; and / or

[0033] 1.500≤10×(ZrO2+P2O5) / Li2O≤1.900; and / or

[0034] 4.200≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤5.900; and / or

[0035] 2.600≤99×(CaO+ZrO2) / (Li2O+Na2O+1000K2O)≤4.950; and / or

[0036] 15.000≤(5.6B2O3+10Al2O3+6.5CaO) / ZrO2≤20.000.

[0037] In some embodiments, the composition of the 3D curved glass-ceramics satisfies the following requirements, expressed in terms of the molar percentage of each oxide in the composition of the 3D curved glass-ceramics:

[0038] 0.186≤5×P2O5 / (Li2O+0.5Al2O3)≤0.243; and / or

[0039] 18.500≤Li2O / P2O5≤24.700; and / or

[0040] 0.190≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.170; and / or

[0041] 1.550≤10×(ZrO2+P2O5) / Li2O≤1.850; and / or

[0042] 4.600≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤5.850; and / or

[0043] 2.680≤99×(CaO+ZrO2) / (Li2O+Na2O+1000K2O)≤4.930; and / or

[0044] 16.000≤(5.6B2O3+10Al2O3+6.5CaO) / ZrO2≤20.000.

[0045] In some embodiments, when the thickness is 0.6 mm, the optical b-value of the 3D curved glass-ceramic is ≤ 1.00, preferably ≤ 0.70, and more preferably ≤ 0.55. A smaller b-value indicates better optical performance of the 3D curved glass-ceramic and a better overall display effect.

[0046] In some embodiments, when the thickness is 0.6 mm, the range of the b-values ​​at nine locations on the main surface of the 3D curved glass-ceramic is ≤ 0.30, preferably ≤ 0.10, and more preferably ≤ 0.06. The smaller the range of the b-values ​​at nine locations on the main surface of the 3D curved glass-ceramic sheet of this specification, the better the overall uniformity of the 3D curved glass-ceramic sheet of this application and the better the overall display effect.

[0047] The nine locations are: (1) the test locations of test circle I close to the four corners of the main surface, a total of four locations; (2) the test locations of four test circles II formed by the points on the line segment formed by the centers of the four test circles I that are closest to the middle of the long side or short side of the main surface, a total of four locations; (3) the location of one test circle III formed by the center point of the main surface as the circle center.

[0048] In some embodiments, when the thickness of the 3D curved glass-ceramics is 0.6 mm, the haze is ≤0.20%, and the transmittance of the glass-ceramics is ≥90.00% under light of a wavelength of 550 nm.

[0049] A substrate glass, which can be used to prepare a 3D curved glass-ceramic as described in any one of the aforementioned embodiments, wherein the composition of the substrate glass, calculated in molar percentage of oxides, comprises:

[0050] SiO2: 60.00mol%-71.00mol%, Al2O3: 1.50mol%-5.00mol%, P2O5: 0.80mol%-1.50mol%, ZrO2: 2.00mol%-4.00mol%, Na2O: 0.00m ol%-1.00mol%, K2O: 0.00mol%-0.50mol%, Li2O: 20.00mol%-30.00mol%, CaO: 0.00mol%-1.60mol%, B2O3: 0.00mol%-1.00mol%;

[0051] The composition of the substrate glass satisfies the following requirements, expressed as a molar percentage of each oxide in the substrate glass composition:

[0052] 0.180≤5×P2O5 / (Li2O+0.5Al2O3)≤0.250;

[0053] 18.200≤Li2O / P2O5≤25.500;

[0054] 0.100≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.200;

[0055] 1.500≤10×(ZrO2+P2O5) / Li2O≤2.000;

[0056] 4.000≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤6.000;

[0057] 2.600≤99×(CaO+ZrO2) / (Li2O+Na2O+1000K2O)≤5.000;

[0058] 12.200≤(5.6B2O3+10Al2O3+6.5CaO) / ZrO2≤20.000. By ensuring that the base glass meets these composition requirements, not only can the base glass bricks achieve good melting conditions, but also prefabricated micro-ceramic bricks with good overall uniformity, good display effects, excellent optical properties, and excellent mechanical properties can be produced, with the main crystal phases being petalite and lithium disilicate. This is conducive to the hot bending of 3D curved micro-ceramic products with excellent optical and mechanical properties.

[0059] In some embodiments, after synchronous thermal analysis testing, under a protective atmosphere of nitrogen, the substrate glass is heated from room temperature to 900°C at a heating rate of 10°C / min to obtain a heating DSC curve. In the heating DSC curve, there are at least two exothermic peaks, wherein the first exothermic peak temperature T1 is 600°C-730°C, and the second exothermic peak temperature T2 is 740°C-800°C, and T1 and T2 satisfy the relationship: 100°C ≥ T2-T1 ≥ 40°C, preferably 80°C ≥ T2-T1 ≥ 50°C. Large-sized substrate glass bricks made with substrate glass solutions that meet specific DSC curve characteristics are heat-treated under the production line process conditions for mass production of microcrystalline glass to produce prefabricated microcrystalline glass bricks whose optical properties and display effects meet the requirements for use in display screens. This can effectively solve the problems in the prior art that, when prefabricated microcrystalline glass bricks are mass-produced, there are large differences in b-values ​​in different areas of the glass bricks, localized undesirable colors, patches, and poor display.

[0060] In some embodiments, at T g -T2 temperature range, the upper limit temperature of precipitation of lithium silicate crystal phase in the substrate glass is tested T max (Li2SiO3) and the upper limit temperature of the precipitation of quartz crystal phase in the matrix glass T max (SiO2), T max (Li2SiO3)≥T max (SiO2), where T g is the glass transition temperature of the substrate glass. By making the substrate glass in a specific temperature range, the upper limit temperature of the precipitation of the quartz crystal phase is met. max (SiO2) is lower than the upper limit temperature of precipitation of lithium silicate crystal phase T max (Li2SiO3), which can ensure that the substrate glass can effectively avoid the precipitation of quartz crystal phase under specific heat treatment process conditions for preparing prefabricated microcrystalline glass with main crystal phases of petalite and lithium disilicate. Combined with the subsequent hot bending process, the lithium monosilicate crystal phase can also be transformed into the required lithium disilicate crystal phase, thereby avoiding the adverse effects of the quartz crystal phase and the lithium monosilicate crystal phase on the optical effect of the microcrystalline glass.

[0061] In some embodiments, the composition of the substrate glass comprises, in terms of mole percentage of oxides:

[0062] SiO2: 67.50 mol%-71.00 mol%, Al2O3: 3.50 mol%-5.00 mol%, P2O5: not less than 0.85 mol% and less than 1.50 mol%, ZrO2: 2.50 mol%-3.50 mol%, Na2O: greater than 0.00 mol% and less than 1.00 mol%, K2O: greater than 0.00 mol% and less than 0.50 mol%, Li2O: 20.00 mol%-25.00 mol%, CaO: greater than 0.50 mol% and less than 1.50 mol%, and B2O3: 0.00 mol%-1.00 mol%. By adjusting the content relationship of the necessary oxides, the network structure of the glass can be further improved, thereby ensuring the production of large-sized prefabricated micro-ceramics with good overall uniformity, and further ensuring the production of 3D curved micro-ceramics with excellent optical and strength properties.

[0063] A method for preparing a 3D curved glass-ceramic as described in any one of the above embodiments, comprising the following steps:

[0064] (1) heat-treating the substrate glass as described in any one of the above embodiments to obtain a prefabricated glass-ceramic product comprising a lithium silicate crystal phase, a lithium disilicate crystal phase, and a petalite crystal phase, and having a crystallinity of not less than 60.00 wt %;

[0065] (2) Processing the prefabricated glass-ceramic product obtained in step (1) into a flat glass-ceramic sheet of required specifications and dimensions, and performing heat bending treatment on the obtained flat glass-ceramic sheet to obtain a 3D curved glass-ceramic, wherein the 3D curved glass-ceramic contains a petalite crystal phase and a lithium disilicate crystal phase, and the petalite crystal phase and the lithium disilicate crystal phase have a higher weight percentage than other crystal phases present in the 3D curved glass-ceramic.

[0066] In some embodiments, in step (1), the heat treatment includes nucleation treatment and crystallization treatment, wherein the temperature of the nucleation treatment is (Tg-20°C) to (Tg+40°C), the time of the nucleation treatment is 0min-6000min, the temperature of the crystallization treatment is (T1-50°C) to T1, and the time of the crystallization treatment is 30min-6000min; Tg is the glass transition temperature of the substrate glass; in step (1), the heating rate of the heat treatment process is 5°C / min-15°C / min.

[0067] In some embodiments, in step (2), the hot bending process includes at least 3 preheating stations, at least 3 hot pressing stations and at least 3 cooling stations; the temperature of the preheating station is 500°C-850°C, the temperature of the hot pressing station is 700°C-900°C, the pressure of the hot pressing station is 0MPa-1MPa, and the temperature of the cooling station is 500°C-800°C.

[0068] In some embodiments, the working time of each preheating station is 90s-360s, the working time of each hot pressing station is 90s-360s, and the working time of each cooling station is 90s-360s.

[0069] A chemically strengthened glass-ceramic, wherein the composition at the center of the chemically strengthened glass-ceramic is the same as the composition of the 3D curved glass-ceramic described in any of the above embodiments, the chemically strengthened glass-ceramic comprising a compressive stress layer region extending from the surface of the chemically strengthened glass-ceramic to a compression depth, and having tensile stress within the chemically strengthened glass-ceramic. Forming the compressive stress layer on the surface of the 3D curved glass-ceramic further improves the mechanical properties of the 3D curved glass-ceramic.

[0070] A glass device, wherein the glass device comprises the 3D curved micro-ceramic glass as described in any one of the above embodiments or comprises the chemically strengthened micro-ceramic glass as described in the above embodiments.

[0071] An electronic device, wherein the electronic device includes the 3D curved microcrystalline glass as described in any one of the above embodiments or includes the chemically strengthened microcrystalline glass as described in the above embodiments.

[0072] The technical solution of this application has at least the following advantages or beneficial effects:

[0073] Through the above-mentioned technical solutions, especially by ensuring that the content of each oxide is within an appropriate range and coordinating the oxide content ratio under specific conditions, the present application can ensure the generation of the main crystalline phase during the mass production of 3D curved microcrystalline glass products. At the same time, it can ensure that the prepared 3D curved microcrystalline glass products present a relatively uniform display effect as a whole, effectively avoiding the problem of large differences in b values ​​in different regions of the mass-produced 3D curved microcrystalline glass products and poor display effects.

[0074] The large-sized substrate glass bricks prepared by the glass solution of this application can ensure that the overall b-value of the main surface of the prefabricated microcrystalline glass bricks is close when they are heat-treated to be prepared into prefabricated microcrystalline glass bricks, thereby ensuring that the 3D curved microcrystalline glass prepared therefrom also presents a good display effect. The solution of the specific composition of this application can ensure that 3D curved microcrystalline glass with good optical properties is obtained, which is conducive to the industrial mass production of 3D curved microcrystalline glass and improves the yield of 3D curved microcrystalline glass products. At the same time, the microcrystalline glass prepared by the above-mentioned substrate glass formula solution can be prepared by chemical strengthening to obtain chemically strengthened microcrystalline glass with excellent strength properties, especially excellent anti-drop performance.

[0075] In the mass production process of 3D curved glass-ceramics whose main crystal phases are petalite and lithium disilicate, products with poor optical display basically contain cristobalite (SiO2) impurity phase. In this application, by adjusting the composition of the substrate glass, the substrate glass is allowed to precipitate the quartz crystal phase within a specific temperature range. max (SiO2) is lower than the upper limit temperature T of the precipitation of lithium silicate crystal phase max (Li2SiO3) can ensure that the substrate glass can effectively avoid the precipitation of quartz crystal phase under specific heat treatment process conditions for preparing prefabricated microcrystalline glass with main crystal phases of petalite and lithium disilicate. Combined with the subsequent hot bending process, the lithium monosilicate crystal phase can also be transformed into the required lithium disilicate crystal phase, thereby avoiding the adverse effects of the quartz crystal phase and the lithium monosilicate crystal phase on the optical effect of the glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0077] FIG1 is a DSC graph of the substrate glass of Example 1 at elevated temperature;

[0078] FIG2 is a DSC graph of the substrate glass of Example 10 at elevated temperatures;

[0079] FIG3 is a DSC graph of the substrate glass of Comparative Example 1 at elevated temperatures;

[0080] FIG4 is a DSC curve of the substrate glass of Comparative Example 2;

[0081] FIG5 is a schematic diagram of the structure of Li3PO4 crystals attached to lithium silicate crystals;

[0082] Figure 6 is a standard XRD diffraction pattern of quartz appearing in glass-ceramics;

[0083] FIG7 is a schematic diagram of nine test positions when performing b-value tests on the main surface of the glass-ceramics;

[0084] FIG8 is an XRD diffraction pattern of the prefabricated glass-ceramics obtained after the substrate glass of Example 2 undergoes heat treatment process C;

[0085] FIG9 is an XRD diffraction pattern of the prefabricated glass-ceramics obtained after the substrate glass of Comparative Example 2 is subjected to heat treatment process C;

[0086] FIG10 is an XRD diffraction curve at the maximum b-value position and the minimum b-value position of the 3D curved glass-ceramics of Example 1;

[0087] FIG11 is an XRD diffraction curve at the maximum b-value position and the minimum b-value position of the 3D curved glass-ceramics of Comparative Example 6;

[0088] FIG12 is a picture of the prefabricated glass-ceramics of Comparative Example 7 cracking during the 3D hot bending process;

[0089] FIG13 is a transmittance curve diagram of the 3D curved glass-ceramics of Example 1. DETAILED DESCRIPTION

[0090] The endpoints and any values ​​of the scope disclosed in this article are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, between the endpoint values ​​of each scope, between the endpoint values ​​of each scope and a separate point value, and between separate point values, one or more new numerical ranges can be combined with each other, and these numerical ranges should be considered as specifically disclosed in this article. Wherein, the terms "optional" and "optional" all refer to and may include, but may not include (or may have, or may not have). As used herein, "and / or" is inclusive, for example, "A and / or B" refers to only A, or only B, or both A and B.

[0091] Glossary and test methods:

[0092] Base glass: also known as basic glass, refers to glass that has not been nucleated, crystallized or strengthened.

[0093] Glass-ceramics: also known as glass ceramics or crystallized glass, is a type of solid composite material that contains both a glass phase and a crystal phase (also known as a microcrystalline phase or a crystal phase).

[0094] 3D curved glass-ceramics: also known as 3D curved glass-ceramics, is made by bending flat glass-ceramics through cold grinding, hot bending or hot pressing, so that both main surfaces of the flat glass-ceramics are curved.

[0095] Chemically strengthened glass-ceramics: refers to the solid composite material obtained by chemically strengthening glass-ceramics.

[0096] In the present application, when high-temperature chemical strengthening treatment is carried out, the alkali metal ions with large ionic radius (such as potassium ions and sodium ions) in the molten salt bath will replace the alkali metal ions with small ionic radius (such as sodium ions and lithium ions) in the microcrystalline glass, thereby generating an exchange ion volume difference and generating compressive stress on the surface of the microcrystalline glass.

[0097] Main crystalline phase: refers to a crystalline phase having a higher weight content than other crystalline phases present in the microcrystalline glass.

[0098] Main surface: refers to the surface with the largest surface area in a glass brick or glass sheet, such as the upper or lower surface of a horizontally placed cover glass.

[0099] Speckling: This refers to the phenomenon where strong light strikes the glass from the side, causing localized color changes on the main surface of the glass and / or uneven coloring across the entire glass, as shown in Figure 8. Products exhibiting speckling fail to meet the display requirements of display cover glass and are therefore considered defective during production.

[0100] Glass transition temperature: T g , unit ℃, also known as the brittle temperature of glass, it is the highest temperature at which glass becomes brittle, and the corresponding viscosity is 10 12 Pa·s, also known as the upper limit of annealing temperature, at which the internal stress of glass products caused by uneven cooling can be eliminated. In this application, T g It is obtained through the heating DSC curve of the substrate glass. It is manifested on the DSC curve as a step in which the baseline changes toward the endothermic direction. The two baseline extension lines before and after the step are tangent to the inflection point of the curve. The average value of the corresponding temperatures of the two intersection points is the glass transition temperature.

[0101] CS_50: refers to the compressive stress value at a depth of 50μm measured from the main surface of the chemically strengthened microcrystalline glass.

[0102] DOL_0: Depth of the compressive stress layer, also known as the depth of the compressive stress layer, refers to the distance from any surface of the glass to the position close to the surface where the compressive stress is zero in the thickness direction of the glass.

[0103] |CT_AV|: The absolute value of the average tensile stress in the tensile stress layer, specifically the absolute value of the average value of all tensile stresses in the tensile stress layer.

[0104] Test conditions for CS_50, |CT_AV|, and DOL_0: Tested using an Orihara SLP-2000 (Japan), with a light source wavelength of 518 nm, SOC = 25.5 (nm / cm) / MPa, refractive index = 1.54, and exposure time: 300 usec.

[0105] When testing surfaces CS_50, |CT_AV|, and DOL_0, first apply conductive fluid to the stress gauge. Then, clean the chemically strengthened glass-ceramic sample and place it on the test path to measure its stress. The stress gauge is an SLP-2000, and the conductive fluid used has a refractive index of 1.51.

[0106] Transmittance: The ratio of the radiant energy projected and transmitted through the object to the total radiant energy projected onto the object in the process of the incident light flux leaving from the illuminated surface or the incident surface of the medium to the other side.

[0107] b value: belongs to the Lab color model, a color model developed by the International Illumination Commission. Positive and negative b values ​​represent yellow and blue.

[0108] Haze: Haze is the percentage of transmitted light intensity that deviates from the incident light by more than 2.5° to the total transmitted light intensity.

[0109] Precursor: A form of existence before obtaining the target object.

[0110] Residual glass phase: refers to the amorphous phase in microcrystalline glass.

[0111] Synchronous thermal analysis test: Using Mettler Toledo TGA / DSC3+ synchronous thermal analyzer, the test is carried out according to the required process. The obtained curve is called DSC curve, including the heating DSC curve.

[0112] Temperature DSC curve test conditions: After grinding the substrate glass and sieving it through a 200-mesh sieve, obtain the sample to be tested. Weigh approximately 20 mg of the sample and heat it from room temperature to 900°C at a heating rate of 10°C / min under a nitrogen atmosphere to obtain the sample's temperature DSC curve. The differential thermal analysis instrument used in this application to test the temperature DSC curve is a Mettler-Toledo TGA / DSC3+ simultaneous thermal analyzer. The standard used in the test is α-Al2O3 powder. The sample container is a platinum crucible. The instrument is placed in an ambient temperature of 24°C and the air humidity is 40%.

[0113] Glass thickness: measured by laser thickness gauge.

[0114] Optical Performance Testing of Glass-Ceramics with a Thickness of 2mm or Less: This application uses a Konica Minolta CM-3600A spectrophotometer in transmission mode to test the haze, L value, a value, and b value of glass-ceramics. The CM-3600A's test aperture is 25.6mm. This application uses a Shimadzu UV-2000 UV-Vis spectrophotometer to test transmittance and its curve. To ensure accuracy, this test method is applicable to glass sheets with a thickness of 2mm or less.

[0115] Determination of crystalline phase: The XRD test results (RAW format) were imported into the X-ray diffraction data Rietveld refinement software JADE Standard 8.6 for fitting and analysis to determine the crystalline phase in the micro-glass-ceramic sample.

[0116] The crystal content in this application refers to the percentage of crystals or crystalline phases in the mass of the microcrystalline glass, which is a weight percentage.

[0117] Determination of Crystalline Content: Import XRD test results (RAW format) into the X-ray diffraction data Rietveld refinement software JADE Standard 8.6 for fitting and calculation to determine the crystal content of the glass-ceramic sample. Specifically, the ratio of the fitted crystalline phase peak area to the total fitted peak area is the crystal content.

[0118] Average crystal size test: The average crystal size of the sample can be calculated using the result data obtained from the XRD test according to the Scherrer formula D = Kλ / (βcosθ). Wherein, λ is the X-ray wavelength, λ = 0.154056nm, β is the half-height width of the diffraction peak, K = 0.89, and θ is the Bragg diffraction angle. Specifically, the RAW file (diffraction pattern) output by the XRD instrument is curve fitted in JADE Standard 8.6 software. Jade outputs a fitting report. According to the angle 2θ value and Peak FWHM value corresponding to each diffraction peak in the fitting report, the Peak FWHM value is converted to radians: β = (FWHM / 180×3.14). The grain size of each diffraction peak is calculated by the Scherrer formula D = Kλ / (βcosθ) and then averaged to obtain the average crystal size.

[0119] Testing method for the upper limit temperature of crystal phase precipitation: Heat the substrate glass at a heating rate of 10°C / min until the substrate glass is heated to Tg, Tg+5°C, Tg+10°C, Tg+15°C, etc., and continue heat treatment at increments of 5°C until T2. The heat treatment time at each temperature ranges from 30 to 240 minutes (the heat treatment time at each temperature in the Examples and Comparative Examples of this application is 240 minutes). The crystal phase composition of the samples obtained by treating the substrate glass at these different heat treatment temperatures is tested to determine the upper limit temperature for the precipitation of the lithium silicate (Li2SiO3) crystal phase and the quartz (SiO2) crystal phase.

[0120] Here, the "upper limit temperature of precipitation of lithium silicate crystal phase" specifically refers to the temperature at which g -T2 temperature range is the highest temperature at which a lithium silicate crystal phase is precipitated in the substrate glass. Above this temperature, lithium silicate will not be precipitated in the substrate glass.

[0121] The "upper limit temperature of the quartz crystal phase" here specifically refers to the temperature at which g -T2 is the maximum temperature at which quartz crystals precipitate from the substrate glass. Above this temperature, quartz will not precipitate from the substrate glass. The standard XRD diffraction pattern of quartz in glass-ceramics is shown in Figure 6.

[0122] Here T g T2 is the second exothermic peak temperature in the DSC curve obtained when the substrate glass is subjected to DSC testing.

[0123] If a certain crystal phase always exists at the temperature point T2, it means that its upper precipitation temperature is greater than T2.

[0124] Fixed height drop test:

[0125] (1) Apply 120-grit sandpaper to the bottom surface of a 187g model machine and place the model machine on a Wonder Inno drop tester.

[0126] (2) Place a glass-ceramic sample to be tested with a length, width and thickness of 50 mm × 50 mm × 0.6 mm on a smooth marble plate directly below the model machine, with the glass-ceramic sample facing the sandpaper;

[0127] (3) Drop the model machine from a fixed height of 1.0 m to impact the glass-ceramic sample located directly below the model machine. If the glass-ceramic sample does not break, replace the sandpaper on the lower surface of the model machine and repeat the above drop impact process until the glass-ceramic breaks. Record the number of drops until the glass-ceramic breaks.

[0128] At least 10 identical glass-ceramic samples from each batch are subjected to a fixed-height drop test. The average value of the test results of the 10 glass-ceramic samples is calculated to characterize the drop resistance of the glass-ceramic.

[0129] Surface Na2O concentration test: The surface Na2O concentration is equal to the surface Na2O mass / total surface oxide mass, where the total surface oxide mass includes oxides such as SiO2, Al2O3, P2O5, ZrO2, Na2O, K2O, CaO that can be accurately tested by XRF, and does not include the content of oxides such as Li2O and B2O3 that cannot be accurately tested by XRF. The surface Na2O concentration of the chemically strengthened microcrystalline glass in this application is measured by X-ray fluorescence spectrometer (XRF). The surface Na element content in the chemically strengthened microcrystalline glass is measured by XRF, and then the surface Na2O concentration is calculated. The calculation method is: surface Na2O concentration = (surface Na element content × relative molecular mass of Na2O) / (relative atomic mass of Na element × 2). It should be understood that the surface Na element content = Na element mass / total element mass, and the total element mass = total oxide mass. The equipment used for the test is Thermo Scientific ARL TM PERFORM'X. The target material was Rh (rhodium), the light tube voltage was 40 kV, the current was 60 mA, the collimator was 0.15, the crystal was LiF200, the detector was FPC, the test range was a 29 mm circle, and the analysis software was UniQuant standardless analysis. XRF testing used standardless testing, and the concentration of elements with atomic numbers 6 and below or their oxides in the glass was not measured. That is, in this application, when measuring the surface Na2O concentration by XRF, the total mass of the surface oxide does not include the mass of elements with atomic numbers 6 and below or their oxides in the glass.

[0130] As described above, the present application provides a 3D curved glass-ceramic, wherein the 3D curved glass-ceramic contains petalite (LiAlSi4O 10 ) crystalline phase and lithium disilicate (Li2Si2O5) crystalline phase, wherein the petalite crystalline phase and the lithium disilicate crystalline phase have a higher weight percentage than other crystalline phases present in the 3D curved microcrystalline glass.

[0131] The 3D curved glass-ceramics of the present application is obtained by subjecting the substrate glass to heat treatment and heat bending treatment. Therefore, it can be understood that, in terms of oxides, the composition of the substrate glass is the same as that of the 3D curved glass-ceramics.

[0132] In the present application, the composition of the 3D curved glass-ceramics or the substrate glass for preparing the 3D curved glass-ceramics includes, in terms of molar percentage of oxides:

[0133] SiO2: 60.00mol%-71.00mol%, Al2O3: 1.50mol%-5.00mol%, P2O5: 0.80mol%-1.50mol%, ZrO2: 2.00mol%-4.00mol%, Na2O: 0.00m ol%-1.00mol%, K2O: 0.00mol%-0.50mol%, Li2O: 20.00mol%-30.00mol%, CaO: 0.00mol%-1.60mol%, B2O3: 0.00mol%-1.00mol%;

[0134] In terms of the content of each oxide expressed in molar percentage in the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics, the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics satisfies:

[0135] 0.180≤5×P2O5 / (Li2O+0.5Al2O3)≤0.250;

[0136] 18.200≤Li2O / P2O5≤25.500;

[0137] 0.100≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.200;

[0138] 1.500≤10×(ZrO2+P2O5) / Li2O≤2.000;

[0139] 4.000≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤6.000;

[0140] 2.600≤99×(CaO+ZrO2) / (Li2O+Na2O+1000K2O)≤5.000;

[0141] 12.200≤(5.6B2O3+10Al2O3+6.5CaO) / ZrO2≤20.000. In the present application, by ensuring that the content of each oxide is within an appropriate range and in combination with the oxide content ratio under specific conditions, the generation of the main crystalline phase can be ensured during the mass production of 3D curved glass-ceramics products. At the same time, the prepared 3D curved glass-ceramics products can be ensured to present a relatively uniform display effect as a whole, effectively avoiding the problem of large differences in b values ​​in different regions of mass-produced 3D curved glass-ceramics products, resulting in poor display effects.

[0142] In the present application, SiO2 is an oxide that forms the network skeleton of the glass, and is used to stabilize the network structure of the substrate glass and 3D curved microcrystalline glass. It is an important component of crystalline phases such as lithium silicate, petalite, β-spodumene and quartz. When the substrate glass is heat-treated to form microcrystalline glass, the SiO2 content should be high enough to form a sufficient amount of petalite crystals and lithium silicate crystals. When the SiO2 content is too low, the glass tends to have a higher thermal expansion coefficient and lower thermal shock resistance; when the SiO2 content is too high, the glass's solubility will deteriorate, or the viscosity of the molten glass will increase, making the glass difficult to clarify, making the glass more difficult to form, reducing productivity, and also causing the crystallization heat treatment time of the substrate glass to be longer. In some embodiments, the 3D curved microcrystalline glass or substrate glass of the present application contains 60.00 mol%-71.00 mol% SiO2. In some embodiments, the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics may contain 60.00mol%-71.00mol%, 60.90mol%-70.00mol%, 60.90mol%-69.00mol%, 60.90mol%-68.00mol%, 62.00mol%-65.00mol%, 63.00mol%-70.00mol%, 64.00mol%-68.00mol%, 65.00mol%-67.00mol% or 67.50mol%-71.00mol% of SiO2. In some embodiments, the 3D curved glass-ceramics or the substrate glass for preparing the 3D curved glass-ceramics may contain 60.00mol%, 61.00mol%, 62.00mol%, 63.00mol%, 64.00mol%, 65.00mol%, 66.00mol%, 67.00mol%, 67.50mol%, 68.00mol%, 69.00mol%, 70.00mol% or 71.00mol% of SiO2, or may contain SiO2 within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass with the required performance of the present application can be obtained. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass with the required performance of the present application can be obtained.

[0143] In the present application, Al2O3 can be used to construct the glass skeleton and is an indispensable component for the formation of petalite. Al2O3 is coordinated around the crystal nucleus to form a "center-shell" structure. This structure makes it difficult for the crystal nucleus components to be supplied from the outer part of the shell, and the crystal nucleus is not easy to grow, and it is easy to form multiple tiny grains. An appropriate amount of Al2O3 can stabilize the glass network structure, improve the mechanical properties and chemical durability, and inhibit the phase separation of the glass, reduce the thermal expansion coefficient, and increase the strain point. When the Al2O3 content is too little, the glass has a tendency to have a higher thermal expansion coefficient, its chemical durability is reduced, and the crystal nucleus becomes larger, and the microcrystalline glass is prone to white turbidity; when the Al2O3 content is too much, the glass's solubility deteriorates, production becomes difficult, and mullite crystals are easily precipitated, causing the glass to lose clarity. In some embodiments, the 3D curved microcrystalline glass of the present application or the base glass for preparing the 3D curved microcrystalline glass contains 1.50 mol% to 5.00 mol%. In some embodiments, the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics may contain 1.50 mol%-5.00 mol%, 3.00 mol%-5.00 mol%, 3.00 mol%-4.00 mol%, 3.00 mol%-4.50 mol%, 3.50 mol%-4.50 mol% or 4.50 mol%-5.00 mol% of Al2O3. In some embodiments, the 3D curved glass-ceramics or the substrate glass used to prepare the 3D curved glass-ceramics may contain 1.50 mol%, 2.00 mol%, 2.50 mol%, 3.00 mol%, 3.20 mol%, 3.80 mol%, 4.00 mol%, 4.40 mol%, 4.80 mol% or 5.00 mol% of Al2O3, or may contain Al2O3 within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained.

[0144] In the present application, Li2O is the main component of the petalite crystal phase and the lithium silicate crystal phase, and is also an essential component for chemical strengthening. An appropriate amount of Li2O is beneficial to ensure that the transparency, melt forming effect, crystallization ability, chemical strengthening performance and other properties of the 3D curved glass-ceramics meet the requirements. When the Li2O content is too little, the glass is prone to precipitate crystalline phases, such as mullite, which makes the glass devitrified, the meltability is reduced or the viscosity is increased, it is difficult to clarify, and the molding becomes difficult; when the Li2O content is too much, the crystallization heat treatment temperature of the substrate glass is reduced, the crystallization ability of the glass becomes too strong, the glass has a tendency to devitrify, and the crystallized glass becomes easily broken. In some embodiments, the 3D curved glass-ceramics of the present application or the substrate glass for preparing the 3D curved glass-ceramics contains 20.00 mol%-30.00 mol% of Li2O. In some embodiments, the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics may contain 20.00 mol%-30.00 mol%, 22.00 mol%-28.00 mol%, 24.00 mol%-26.00 mol%, 20.00 mol%-24.00 mol%, 24.00 mol%-30.00 mol%, 20.00 mol%-22.00 mol%, 28.00 mol%-30.00 mol% or 21.00 mol%-28.00 mol% of Li2O. In some embodiments, the 3D curved glass-ceramics or the substrate glass for preparing the 3D curved glass-ceramics may contain 20.50 mol%, 21.50 mol%, 22.50 mol%, 23.50 mol%, 24.50 mol%, 25.50 mol%, 26.50 mol%, 27.50 mol%, 28.50 mol%, 29.50 mol% or 30.00 mol% of Li2O, or may contain Li2O within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass with the performance required by the present application can be obtained.

[0145] In this application, P2O5 is a glass-forming oxide, existing as phosphorus-oxygen tetrahedrons [PO4] within a network structure. P2O5 appears preferentially during the heat treatment process, first causing the glass to phase separate and aggregate, forming the amorphous precursor phase Li3PO4. Li3PO4 then serves as a non-uniform nucleation site, allowing crystalline phases such as lithium silicate to grow attached to the amorphous Li3PO4. As the P2O5 content increases, the number of non-uniform nucleation sites increases, effectively refining the grains centered around Li3PO4. This improves the overall transmittance of the glass-ceramics, improves the uniformity of the glass, and reduces the b-value. Within a certain P2O5 range, the gain effect is optimal. However, when the P2O5 content is too high, the upper crystallization temperature rises, which easily generates more Li3PO4 crystals, resulting in insufficient Li2O to form lithium silicate and petalite. This in turn causes quartz crystals to precipitate in the base glass, resulting in a decrease in the transmittance of the glass-ceramics and the overall optical uniformity of the glass-ceramics. In worse cases, the base glass may directly crystallize during melt molding. When the P2O5 content is too low, coarse ZrO2 crystals are easily precipitated, causing the glass to lose clarity.

[0146] In some embodiments, the 3D curved glass-ceramics of the present application or the substrate glass for preparing the 3D curved glass-ceramics contains 0.80 mol%-1.50 mol%. P2O5 in this content range is beneficial to ensuring high transmittance, good optical uniformity, significantly reducing the b value, and achieving the best gain effect of the 3D curved glass-ceramics. In some embodiments, the 3D curved glass-ceramics or the substrate glass for preparing the 3D curved glass-ceramics may contain 0.80 mol%-1.50 mol%, 0.80 mol%-1.30 mol%, 1.30 mol%-1.50 mol%, 0.80 mol%-1.00 mol%, 1.00 mol%-1.30 mol%, or 1.10 mol%-1.50 mol%. In some embodiments, the 3D curved glass-ceramics or the substrate glass used to prepare the 3D curved glass-ceramics may contain 0.85 mol%, 0.95 mol%, 1.00 mol%, 1.10 mol%, 1.20 mol%, 1.35 mol%, 1.40 mol% or 1.50 mol% of P2O5, or may contain P2O5 within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained.

[0147] In the present application, since P2O5 preferentially generates amorphous Li3PO4 during the heat treatment process, the increase in P2O5 will inevitably compete for more Li2O, thereby reducing the production of lithium silicate and petalite, and therefore a certain degree of Li2O needs to be supplemented. In this regard, in the present application, based on the content expressed by the molar percentage of each oxide in the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics, the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics satisfies: 18.200≤Li2O / P2O5≤25.500, where the chemical formula represents the molar percentage of the oxide, which is beneficial to ensure the formation of the main crystalline phase and improve the strength performance of the glass. In some embodiments, the value of Li2O / P2O5 can be, for example, 18.200, 18.500, 19.000, 19.500, 20.000, 20.500, 21.000, 21.500, 22.000, 22.500, 23.000, 23.500, 24.000, 24.500, 25.000 or 25.500, or can be a value within the numerical range formed by any two of the above specific values ​​as endpoints, as long as the 3D curved microcrystalline glass or substrate glass with the required performance of the present application can be obtained.

[0148] In some embodiments, based on the content of each oxide expressed as a molar percentage in the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics, the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics satisfies: 0.180≤5×P2O5 / (Li2O+0.5Al2O3)≤0.250, where the chemical formula represents the molar percentage of the oxide, thereby facilitating the formation of petalite and lithium disilicate main crystalline phases. In some embodiments, the value of 5×P2O5 / (Li2O+0.5Al2O3) can be, for example, 0.180, 0.184, 0.190, 0.200, 0.210, 0.220, 0.230, 0.240, 0.245 or 0.250, or can be a value within the numerical range formed by any two of the above specific values ​​as endpoints, as long as the 3D curved microcrystalline glass or substrate glass with the performance required by the present application can be obtained.

[0149] In some embodiments, based on the content of each oxide expressed as a molar percentage in the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics, the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics satisfies the following: 4.000≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤6.000, where the chemical formula represents the molar percentage of the oxide, thereby facilitating ensuring the optical properties of the 3D curved glass-ceramics. In some embodiments, the value of (SiO2-7Al2O3-Li2O) / (P2O5+ZrO2) can be, for example, 4.000, 4.200, 4.500, 5.000, 5.500, or 6.000, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or base glass for preparing the 3D curved glass-ceramics can achieve the performance required by the present application.

[0150] In the present application, an appropriate amount of ZrO2 can improve the viscosity, hardness, elastic modulus, refractive index, chemical stability of the glass and reduce the thermal expansion coefficient of the glass. ZrO2 does not play the role of a nucleating agent in the microcrystalline glass with petalite and lithium silicate structure. ZrO2 exists in the residual glass phase after heat treatment, which effectively improves the mechanical properties of the residual glass phase. However, excessive ZrO2 will increase the difficulty of melting the substrate glass, and a white zirconium precipitate will be produced during discharge, which is not conducive to the production of transparent microcrystalline glass. In some embodiments, the 3D curved microcrystalline glass of the present application or the substrate glass for preparing the 3D curved microcrystalline glass contains 2.00 mol%-4.00 mol%. ZrO2 that meets this content range is conducive to the production of transparent 3D curved microcrystalline glass and is conducive to improving the mechanical properties of 3D curved microcrystalline glass. In some embodiments, the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics may contain 2.00mol%-4.00mol%, 2.50mol%-3.50mol%, 2.70mol%-3.30mol%, 2.90mol%-3.10mol%, 2.50mol%-3.00mol%, 2.50mol%-2.80mol%, 2.80mol%-3.50mol%, 2.80mol%-3.40mol%, 2.80mol%-3.30mol% or 2.80mol%-3.10mol% of ZrO2. In some embodiments, the 3D curved glass-ceramics or the substrate glass for preparing the 3D curved glass-ceramics may contain 2.00 mol%, 2.50 mol%, 2.75 mol%, 2.95 mol%, 3.15 mol%, 3.25 mol%, 3.35 mol%, 3.50 mol% or 4.00 mol% ZrO2, or may contain ZrO2 within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained.

[0151] In some embodiments, based on the content of each oxide expressed as a molar percentage in the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics, the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics satisfies the following: 1.500≤10×(ZrO2+P2O5) / Li2O≤2.000, where the chemical formula represents the molar percentage of the oxide, thereby facilitating ensuring the strength performance of the 3D curved glass-ceramics. In some embodiments, the value of 10×(ZrO2+P2O5) / Li2O can be, for example, 1.500, 1.550, 1.600, 1.700, 1.800, 1.900, 1.95, or 2.000, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or base glass having the performance required by the present application can be obtained.

[0152] In this application, B2O3 helps lower the melting temperature of the substrate glass. B2O3 is composed of boron oxide triangles [BO3] and boron oxide tetrahedra [BO4] as structural units. As the B2O3 content increases, the relative proportions of boron oxide triangles and tetrahedra change, leading to a reversal of structure and properties. An appropriate amount of B2O3 helps lower the melting temperature of the substrate glass, improving the transmittance, overall uniformity, and other properties of the 3D curved glass-ceramics. However, when too much B2O3 is added, on the one hand, the three-dimensional framework structure of the boron oxide tetrahedron [BO4] is transformed into a two-dimensional layered structure of the boron oxide triangle [BO3]. The three-coordinated boron oxide triangle [BO3] is not as strong as the boron oxide tetrahedron [BO4], which will have the effect of opening the network structure. At the same time, the increase in the B2O3 content in the residual glass phase will reduce the viscosity of the residual glass phase and promote the growth of crystals such as lithium silicate. On the other hand, it will reduce the temperature of the second exothermic peak of the heating DSC curve of the substrate glass, increase the precipitation of SiO2 crystal phase (such as cristobalite), affect the glass transmittance, and also deteriorate the overall uniformity of the glass brick. In some embodiments, the 3D curved microcrystalline glass of the present application or the substrate glass used to prepare the 3D curved microcrystalline glass contains 0.00mol%-1.00mol%. In some embodiments, the 3D curved glass-ceramics or substrate glass may contain 0.00mol%-1.00mol%, 0.10mol%-0.90mol%, 0.30mol%-0.80mol%, 0.50mol%-0.70mol%, 0.00mol%-0.60mol%, 0.00mol%-0.50mol%, 0.60mol%-1.00mol%, 0.50mol%-1.00mol% or 0.30mol%-0.50mol% B2O3. In some embodiments, the 3D curved glass-ceramics or the substrate glass used to prepare the 3D curved glass-ceramics may contain 0.00 mol%, 0.15 mol%, 0.25 mol%, 0.35 mol%, 0.45 mol%, 0.55 mol%, 0.75 mol%, 0.95 mol% or 1.00 mol% of B2O3, or may contain B2O3 within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained.

[0153] In this application, Na2O is an oxide external to the glass network, providing free oxygen, increasing the oxygen-to-silicon ratio in the glass structure and regulating grain size. The presence of an appropriate amount of Na2O promotes the precipitation of lithium disilicate crystals, reduces the tendency of glass to crystallize, and increases the transmittance of the glass. Furthermore, it improves the thermal stability, chemical stability, mechanical strength, and weather resistance of the glass. In some embodiments, the 3D curved glass-ceramics of this application, or the base glass used to prepare the 3D curved glass-ceramics, contains 0.00 mol% to 1.00 mol% Na2O. In some embodiments, the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics may contain 0.00mol%-1.00mol%, 0.20mol%-0.90mol%, 0.40mol%-0.80mol%, 0.00mol%-0.40mol%, 0.00mol%-0.50mol%, 0.00mol%-0.40mol%, 0.40mol%-1.00mol%, 0.30mol%-0.50mol% or 0.40mol%-0.60mol% of Na2O. In some embodiments, the 3D curved glass-ceramics or the substrate glass used to prepare the 3D curved glass-ceramics may contain 0.00 mol%, 0.15 mol%, 0.35 mol%, 0.55 mol%, 0.75 mol%, 0.95 mol% or 1.00 mol% of Na2O, or may contain Na2O within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained.

[0154] In this application, K2O is an oxide outside the glass network. A proper amount of K2O can reduce the tendency of glass to crystallize and increase the transparency and gloss of the glass. However, when the K2O content is too high, the crystallization ability of the glass becomes stronger, the glass is prone to devitrification, and the crystallized glass is easily broken. + The ionic radius is larger than that of Li + , it is not easy to enter the crystal, so the K +Remains in the glass phase. Therefore, in some embodiments, the 3D curved glass-ceramics of the present application or the substrate glass for preparing the 3D curved glass-ceramics contains 0.00 mol%-0.50 mol%. In some embodiments, the 3D curved glass-ceramics or the substrate glass for preparing the 3D curved glass-ceramics may contain 0.00 mol%-0.50 mol%, 0.10 mol%-0.40 mol%, 0.20 mol%-0.30 mol%, 0.00 mol%-0.20 mol%, 0.30 mol%-0.50 mol%, 0.10 mol%-0.20 mol% or 0.20 mol%-0.40 mol%. In some embodiments, the 3D curved glass-ceramics or the substrate glass used to prepare the 3D curved glass-ceramics may contain 0.00 mol%, 0.15 mol%, 0.25 mol%, 0.35 mol%, 0.45 mol%, or 0.50 mol% of K2O, or may contain K2O within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained.

[0155] In the present application, CaO is beneficial to increase the chemical stability and mechanical strength of the glass. CaO reduces the viscosity of the glass, enhances the solubility and formability of the glass, and is also beneficial to adjust the thermal expansion coefficient and refractive index of the microcrystalline glass. However, when the CaO content is too high, the glass is prone to devitrification after crystallization. Excessive CaO residues in the glass phase produce a refractive index difference with the main crystal phase, which will cause the transmittance of the microcrystalline glass to decrease and the haze to increase. In some embodiments, the 3D curved microcrystalline glass of the present application or the base glass for preparing the 3D curved microcrystalline glass contains 0.00 mol%-1.60 mol% CaO. In some embodiments, the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics may contain 0.00mol%-1.60mol%, 0.50mol%-1.60mol%, 0.60mol%-1.50mol%, 0.80mol%-1.30mol%, 1.00mol%-1.20mol%, 0.50mol%-1.00mol%, 0.50mol%-0.85mol%, 0.85mol%-1.40mol%, 1.40mol%-1.60mol%, 0.85mol%-1.20mol%, 1.20mol%-1.60mol%, 0.85mol%-1.00mol%, 0.85mol%-0.90mol% or 1.00mol%-1.30mol% of CaO. In some embodiments, the 3D curved glass-ceramics or the substrate glass used to prepare the 3D curved glass-ceramics may contain 0.00 mol%, 0.50 mol%, 0.70 mol%, 0.85 mol%, 1.10 mol%, 1.25 mol%, 1.35 mol%, 1.45 mol% or 1.60 mol% of CaO, or may contain CaO within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics or substrate glass having the performance required by the present application can be obtained.

[0156] In some embodiments, based on the content of each oxide expressed as a molar percentage in the composition of the 3D curved glass-ceramic or the base glass for preparing the 3D curved glass-ceramic, the composition of the 3D curved glass-ceramic or the base glass for preparing the 3D curved glass-ceramic satisfies: 0.100≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.200, where the chemical formula represents the molar percentage of the oxide, thereby facilitating the formation of a 3D curved glass-ceramic that meets a specific structure and has excellent performance (especially the forming performance, optical performance and strength performance of the 3D curved glass-ceramic). In some embodiments, the value of P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3) can be, for example, 0.100, 0.150, 0.190, 0.200, 0.205, 0.210, 0.250, 0.300, 0.350, 0.380, 0.400, 0.600, 0.800, 1.000, 1.200, 1.400, 1.600, 1.800, 2.000 or 2.200, or can be a value within the numerical range formed by any two of the above specific values ​​as endpoints, as long as the 3D curved microcrystalline glass or substrate glass with the performance required by the present application can be obtained.

[0157] In some embodiments, based on the content of each oxide expressed as a molar percentage in the composition of the 3D curved glass-ceramic or the base glass for preparing the 3D curved glass-ceramic, the composition of the 3D curved glass-ceramic or the base glass for preparing the 3D curved glass-ceramic satisfies: 2.600≤99×(CaO+ZrO2) / (Li2O+Na2O+1000×K2O)≤5.000, where the chemical formula represents the molar percentage of the oxide, thereby facilitating the formation of a 3D curved glass-ceramic that meets a specific structure and has excellent performance (especially the strength performance of the 3D curved glass-ceramic). In some embodiments, the value of 99×(CaO+ZrO2) / (Li2O+Na2O+1000×K2O) can be 2.600, 2.800, 3.000, 3.500, 4.000 or 5.000, or can be a value within the numerical range formed by any two of the above specific values ​​as endpoints, as long as the 3D curved microcrystalline glass or substrate glass with the performance required by the present application can be obtained.

[0158] In some embodiments, based on the content of each oxide expressed as a molar percentage in the composition of the 3D curved glass-ceramic or the base glass for preparing the 3D curved glass-ceramic, the composition of the 3D curved glass-ceramic or the base glass for preparing the 3D curved glass-ceramic satisfies: 12.200≤(5.6×B2O3+10×Al2O3+6.5×CaO) / ZrO2≤20.000, where the chemical formula represents the molar percentage of the oxide, thereby facilitating the formation of a 3D curved glass-ceramic that meets a specific structure and has excellent performance (especially the optical and mechanical properties of the 3D curved glass-ceramic). In some embodiments, the value of (5.6×B2O3+10×Al2O3+6.5×CaO) / ZrO2 can be 12.200, 13.000, 14.000, 15.000, 16.000, 17.000, 18.000, 19.000 or 20.000, or can be a value within the numerical range formed by any two of the above specific values ​​as endpoints, as long as the 3D curved microcrystalline glass or substrate glass with the performance required by the present application can be obtained.

[0159] In some embodiments, the 3D curved glass-ceramic is transparent in the visible light range, where visible light refers to light within the wavelength range of 360nm-780nm. "Transparent in the visible light range" means that the average transmittance within the wavelength range of 360nm-780nm is greater than 80%, which can meet the optical performance requirements of the front cover display. In some embodiments, the average transmittance of the 0.6mm thick 3D curved glass-ceramic in the visible light range is not less than 90%.

[0160] In some embodiments, the composition of the 3D curved glass-ceramics or the substrate glass for preparing the 3D curved glass-ceramics, measured in molar percentage of oxides, includes: SiO2: 67.50 mol%-71.00 mol%, Al2O3: 3.50 mol%-5.00 mol%, P2O5: not less than 0.85 mol% and less than 1.50 mol%, ZrO2: 2.50 mol%-3.50 mol%, Na2O: greater than 0.00 mol% and not greater than 1.00 mol%, K2O: greater than 0.00 mol% and not greater than 0.50 mol%, Li2O: 20.00 mol%-25.00 mol%, CaO: greater than 0.50 mol% and not greater than 1.50 mol%, and B2O3: 0.00 mol%-1.00 mol%.

[0161] In some embodiments, the 3D curved microcrystalline glass does not contain a quartz crystal phase. The standard XRD diffraction pattern of quartz in the microcrystalline glass is shown in Figure 6. In a microcrystalline glass whose main crystal phases are petalite crystal phase and lithium disilicate crystal phase, if a quartz crystal phase is precipitated, it will have an adverse effect on the optical properties of the microcrystalline glass, easily leading to a decrease in the transmittance of the microcrystalline glass, and it will also easily cause the overall uniformity of the microcrystalline glass brick to deteriorate, and then there will be a problem of large differences in b-values ​​in different areas of the glass. The ratio of each oxide in the present application can enable the base glass to mass-produce 3D curved microcrystalline glass without a quartz crystal phase under specific heat treatment process conditions.

[0162] In some embodiments, the total content of the petalite crystalline phase and the lithium disilicate crystalline phase in the 3D curved glass-ceramics is greater than 60.00 wt%, preferably greater than 70.00 wt%, and more preferably greater than 80.00 wt%. A higher content of the petalite crystalline phase and the lithium disilicate crystalline phase helps improve the mechanical strength of the 3D curved glass-ceramics. The total content of the petalite crystalline phase and the lithium disilicate crystalline phase as a percentage by weight of the mass of the glass-ceramics can be, for example, 60.00wt%, 65.00wt%, 68.00wt%, 70.00wt%, 75.00wt%, 80.00wt%, 85.00wt%, 90.00wt%, 93.00wt%, 95.00wt%, 98.00wt% or 100.00wt%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics with the required performance of the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics with the required performance of the present application can be obtained.

[0163] In some embodiments, in the 3D curved glass-ceramics, the petalite crystalline phase accounts for 35.00 wt% to 50.00 wt% of the mass of the transparent glass-ceramics, and the lithium disilicate crystalline phase accounts for 35.00 wt% to 50.00 wt% of the mass of the transparent glass-ceramics. In some embodiments, the percentage of the lithium disilicate crystalline phase or the petalite crystalline phase in the mass of the transparent glass-ceramics can be 35.00 wt% to 50.00 wt%, 35.00 wt% to 45.00 wt%, 35.00 wt% to 40.00 wt%, or 40.00 wt% to 50.00 wt%. In some embodiments, the glass-ceramics may contain 35.00 wt%, 40.00 wt%, 45.00 wt%, or 50.00 wt% of a lithium disilicate crystalline phase or a petalite crystalline phase, or may contain a lithium disilicate crystalline phase or a petalite crystalline phase within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics with the performance required by the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics with the performance required by the present application can be obtained.

[0164] In some embodiments, the glass-ceramics contains one or more of a lithium silicate (Li2SiO3) crystal phase, a lithium phosphate (Li3PO4) crystal phase, and a spodumene crystal phase as a secondary crystalline phase. In some embodiments, in the glass-ceramics, the secondary crystalline phase accounts for less than 20.00wt% of the mass of the transparent glass-ceramics. The glass-ceramics of the present application has a low content of secondary crystalline phases, which is more conducive to ensuring a high content of the main crystalline phase, and thus ensuring the excellent mechanical strength properties of the glass-ceramics. In some embodiments, the lithium phosphate (Li3PO4) crystal phase is usually accompanied by the growth of secondary phases such as a lithium silicate (Li2SiO3) crystal phase, as shown in Figure 5.

[0165] In some embodiments, in the transparent glass-ceramics, a lithium silicate crystal phase accounts for less than 8.00 wt% of the mass of the transparent glass-ceramics, and the total amount of the lithium phosphate crystal phase and the spodumene crystal phase accounts for less than 8.00 wt% of the mass of the transparent glass-ceramics.

[0166] In some embodiments, the average crystal size of the 3D curved glass-ceramics does not exceed 100 nm, and may be, for example, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm, or may be within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics having the desired performance of the present application can be obtained. It should be understood that, in specific embodiments, any of the above ranges may be combined with any other ranges, as long as the transparent 3D curved glass-ceramics having the desired performance of the present application can be obtained.

[0167] In some embodiments, the crystallinity of the 3D curved glass-ceramics is ≥70.00wt%, preferably ≥80.00wt%, which is beneficial to improving the mechanical strength performance of the glass-ceramics. The "crystallinity" here refers to the percentage of the content of all crystalline phases / crystals in the 3D curved glass-ceramics to the mass of the 3D curved glass-ceramics, for example, it can be 70.00wt%, 80.00wt%, 85.00wt%, 90.00wt%, 93.00wt%, 95.00wt%, 98.00wt% or 100.00wt%, or it can be a value within the numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics with the required performance of this application can be obtained. It should be understood that in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics with the required performance of this application can be obtained.

[0168] In some embodiments, when the thickness is 0.6 mm, the optical b value of the 3D curved glass-ceramics is ≤1.00, preferably the optical b value is ≤0.70, and more preferably the optical b value is ≤0.55. In some embodiments, the optical b value of the 3D curved glass-ceramics at this thickness can be 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90 or 1.00, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints, as long as the 3D curved glass-ceramics with the required performance of the present application can be obtained. It should be understood that, in a specific embodiment, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics with the required performance of the present application can be obtained.

[0169] The nine locations are shown in Figure 7, namely: (1) four test locations of test circle I near the four corners of the main surface; (2) four test locations of test circle II formed by the point closest to the middle of the long side or short side of the main surface on the line segment formed by the centers of the four test circles I; and (3) one test circle III formed by the center point of the main surface. The diameter of the test circle depends on the size of the instrument's test window (which is a circle).

[0170] In some embodiments, when the thickness is 0.6 mm, the range of the b-values ​​at nine locations on the main surface of the 3D curved glass-ceramics is ≤0.30, preferably the range of the b-values ​​at nine locations on the main surface is ≤0.10, and more preferably the range of the b-values ​​at nine locations on the main surface is ≤0.06. In some embodiments, the range of the b-values ​​at nine locations on the main surface of the 3D curved glass-ceramics at this thickness can be 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.20, 0.25 or 0.30, or can be a value within the numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the 3D curved glass-ceramics with the required performance of the present application can be obtained.

[0171] In some embodiments, when the thickness of the 3D curved glass-ceramics is 0.6 mm, the haze is ≤ 0.20%, and the transmittance of the glass-ceramics is ≥ 90.00% under 550 nm wavelength light. The b value here refers to the b value at any position of the glass-ceramics. In some embodiments, the transmittance of 0.6 mm thick glass-ceramics at 550 nm wavelength light can be 90.00%, 90.50%, 91.00%, 92.00%, 93.00%, 94.00%, 95.00%, 96.00%, 97.00%, 98.00%, 99.00% or 100.00%, or a transmittance within a numerical range consisting of any two of the above specific values ​​as endpoints. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other ranges, as long as the glass-ceramics with the performance required by this application can be obtained.

[0172] As described above, the range of the nine b values ​​on the main surface of the 3D curved microcrystalline glass mass-produced in the present application is small, that is, the b values ​​in different areas of the 3D curved microcrystalline glass are close; and the 3D curved microcrystalline glass of the present application has high transmittance, low b value, and low haze, which indicates that the 3D curved microcrystalline glass mass-produced by the production line of the present application has better optical performance and good display uniformity, and can meet the application requirements of display screen cover.

[0173] The present application also provides a substrate glass, which can be used to prepare the 3D curved microcrystalline glass described above, wherein the composition of the substrate glass is the same as that of the aforementioned 3D curved microcrystalline glass in terms of the molar percentage of oxides.

[0174] In some embodiments, according to a simultaneous thermal analysis test, under a protective atmosphere of nitrogen, the substrate glass is heated from room temperature to 900°C at a heating rate of 10°C / min to obtain a heating DSC curve. In the heating DSC curve, there are at least two exothermic peaks, wherein the first exothermic peak temperature T1 is 600°C-730°C, and the second exothermic peak temperature T2 is 740°C-800°C, and T1 and T2 satisfy the relationship: 100°C ≥ T2-T1 ≥ 40°C, preferably 80°C ≥ T2-T1 ≥ 50°C.

[0175] In some embodiments, at T g -T2 temperature range, the upper limit temperature of precipitation of lithium silicate crystal phase in the substrate glass is tested T max (Li2SiO3) and the upper limit temperature of the precipitation of quartz crystal phase in the matrix glass T max (SiO2), T max (Li2SiO3)≥T max (SiO2), where T g T2 is the second exothermic peak temperature in the above-mentioned temperature-increasing DSC curve.

[0176] Large-sized substrate glass bricks made of a specific substrate glass solution that meets specific thermal properties can be heat-treated under the production line process conditions for mass production of 3D curved micro-ceramics to produce prefabricated micro-ceramics bricks with uniform b-value distribution. Flat micro-ceramics products made from slices of this prefabricated micro-ceramics brick can be heat-bent to obtain 3D curved micro-ceramics with better display effects. Moreover, by making the substrate glass meet the upper limit temperature T of the precipitation of the quartz crystal phase within a specific temperature range, max (SiO2) is lower than the upper limit temperature of precipitation of lithium silicate crystal phase T max (Li2SiO3), which can ensure that the substrate glass can effectively avoid the precipitation of quartz crystal phase under specific heat treatment process conditions for preparing prefabricated microcrystalline glass with main crystal phases of petalite and lithium disilicate. Combined with the subsequent hot bending process, the lithium monosilicate crystal phase can also be transformed into the required lithium disilicate crystal phase, thereby avoiding the adverse effects of the quartz crystal phase and the lithium monosilicate crystal phase on the optical effect of the microcrystalline glass.

[0177] Before preparing large-sized prefabricated microcrystalline glass bricks, a small sample of the base glass can be made according to the glass formula. By obtaining the above-mentioned characteristics, it can be verified whether the glass solution is suitable for mass production of qualified 3D curved microcrystalline glass products on the production line. If it is not suitable, adjustments can be made in time, which can greatly save time and cost and effectively avoid waste of resources.

[0178] In some embodiments, the composition of the 3D curved glass-ceramics or the substrate glass for preparing the 3D curved glass-ceramics, measured in molar percentage of oxides, includes:

[0179] SiO2: 67.50mol%-71.00mol%, Al2O3: 3.50mol%-5.00mol%, P2O5: not less than 0.85mol% and less than 1.50mol%, ZrO2: 2.50mol%-3.50mol%, Na2O: greater than 0.00mol% and not more than 1.00mol%, K2O: greater than 0.00mol% and not more than 0.50mol%, Li2O: 20.00mol%-25.00mol%, CaO: greater than 0.50mol% and not more than 1.50mol%, B2O3: 0.00mol%-1.00mol%;

[0180] In terms of the content of each oxide expressed in molar percentage in the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics, the composition of the 3D curved glass-ceramics or the base glass for preparing the 3D curved glass-ceramics satisfies:

[0181] 0.180≤5×P2O5 / (Li2O+0.5Al2O3)≤0.250;

[0182] 18.200≤Li2O / P2O5≤25.500;

[0183] 0.190≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.200;

[0184] 1.500≤10×(ZrO2+P2O5) / Li2O≤2.000;

[0185] 4.000≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤6.000;

[0186] 2.600≤99×(CaO+ZrO2) / (Li2O+Na2O+1000K2O)≤5.000;

[0187] 12.200≤(5.6B2O3+10Al2O3+6.5CaO) / ZrO2≤20.000.

[0188] The present application also provides a method for preparing 3D curved glass-ceramics, which comprises the following steps:

[0189] (1) heat-treating the aforementioned substrate glass to obtain a prefabricated glass-ceramic product comprising a lithium silicate crystal phase, a lithium disilicate crystal phase, and a petalite crystal phase, and having a crystallinity of not less than 60.00 wt %;

[0190] (2) Processing the prefabricated glass-ceramic product obtained in step (1) into a flat glass-ceramic sheet of required specifications and dimensions, and performing heat bending treatment on the obtained flat glass-ceramic sheet to obtain a 3D curved glass-ceramic, wherein the 3D curved glass-ceramic contains a petalite crystal phase and a lithium disilicate crystal phase, and the petalite crystal phase and the lithium disilicate crystal phase have a higher weight percentage than other crystal phases present in the glass-ceramic.

[0191] In some embodiments, the process of preparing 3D curved microcrystalline glass of the present application may also include conventional cold working of prefabricated microcrystalline glass products (such as bricks) obtained by heat treatment of the substrate glass to obtain flat microcrystalline glass of the required specifications and dimensions (such as a thickness of 0.2 mm to 2.0 mm), and then performing the hot bending treatment in step (2). The cold working treatment here includes but is not limited to shaping treatment, slicing treatment, CNC treatment, grinding treatment, polishing treatment, etc. commonly used in the art. Those skilled in the art can select one or more of the above methods to perform cold working on the microcrystalline glass according to actual needs.

[0192] In the present application, the hot bending process may be accompanied by further crystallization of the prefabricated microcrystalline glass product, resulting in the crystallinity of the finally prepared 3D curved microcrystalline glass being no less than that of the prefabricated microcrystalline glass product.

[0193] In this application, the crystallinity of the prefabricated microcrystalline glass product obtained by heat treatment of the substrate glass is 60wt%-90wt%, preferably 65wt%-90wt%; the crystallinity of the 3D curved microcrystalline glass obtained by hot bending treatment of the prefabricated microcrystalline glass product is 70wt%-99wt%, preferably 80wt%-99wt%.

[0194] In the present application, in the above step (1), the conditions for the heat treatment are relatively wide, and those skilled in the art can select from the existing technology according to actual needs. In some embodiments, in step (1), the heat treatment includes nucleation treatment and crystallization treatment, wherein the temperature of the nucleation treatment is (Tg-20°C) to (Tg+40°C), the time of the nucleation treatment is 0min-6000min, the temperature of the crystallization treatment is (T1-50°C) to T1, and the time of the crystallization treatment is 30min-6000min; Tg is the glass transition temperature of the substrate glass, and T1 is the first exothermic peak temperature in the DSC curve of the substrate glass; in step (1), the heating rate of the heat treatment process is 5°C / min-15°C / min. It should be understood that in the present application, the nucleation treatment is to heat up to the specified nucleation treatment temperature (also called nucleation temperature), and after reaching the nucleation treatment temperature, keep warm for a certain time, and the holding time here is the nucleation treatment time (also called nucleation time). The crystallization process involves raising the temperature to a specified crystallization temperature (also known as the crystallization temperature) and then maintaining the temperature for a specified period of time after reaching the crystallization temperature. The holding time is referred to as the crystallization time (also known as the crystallization time). The aforementioned heat treatment conditions facilitate the production of prefabricated glass-ceramics with a specific and uniform microstructure. These prefabricated glass-ceramics can be used for hot bending to produce 3D curved glass-ceramics with petalite and lithium disilicate as the primary crystalline phases and excellent optical and mechanical properties.

[0195] In some embodiments, in step (1), the heat treatment includes a nucleation treatment and a crystallization treatment, wherein the temperature of the nucleation treatment is (Tg-20°C) to (Tg+40°C), for example, (Tg-20°C), (Tg-15°C), (Tg-10°C), (Tg-5°C), (Tg-2°C), Tg, (Tg+2°C), (Tg+5°C), (Tg+10°C), (Tg+15°C), or (Tg+40°C), or any value between these adjacent values. Wherein, Tg is the glass transition temperature of the substrate glass.

[0196] In some embodiments, in step (1), the time of the nucleation treatment is 30 min-360 min, for example, it can be 30 min, 50 min, 70 min, 100 min, 130 min, 150 min, 180 min, 200 min, 250 min, 280 min, 300 min, 330 min, 360 min, 600 min, 1000 min, 2000 min, 3000 min, 4000 min, 5000 min or 6000 min, or any value between these adjacent point values.

[0197] In some embodiments, in step (1), the temperature of the crystallization treatment is ((T1-50°C) to T1, for example, it can be (T1-50°C), (T1-45°C), (T1-40°C), (T1-35°C), (T1-30°C), (T1-25°C), (T1-20°C), (T1-15°C), (T1-10°C), (T1-5°C) or T1, or any value between these adjacent point values.

[0198] In some embodiments, in step (1), the crystallization treatment time is 30 min-600 min, for example, it can be 30 min, 50 min, 70 min, 100 min, 130 min, 150 min, 180 min, 200 min, 250 min, 280 min, 300 min, 330 min, 360 min, 400 min, 450 min, 500 min, 550 min, 600 min, 1000 min, 2000 min, 3000 min, 4000 min, 5000 min or 6000 min, or any value between these adjacent point values.

[0199] In some embodiments, in step (1), the heating rate of the heat treatment process is 5°C / min-15°C / min, for example, 5°C / min, 8°C / min, 10°C / min, 12°C / min, 14°C / min, or 15°C / min, or any value between these adjacent values. Here, the "heating rate" includes the heating rate of the entire heat treatment process, that is, the heating rate of the nucleation process and the heating rate of the crystallization process.

[0200] In some embodiments, in step (2), the hot bending process includes at least three preheating stations, at least three hot pressing stations, and at least three cooling stations; the temperature of the preheating station is 500°C-850°C, the temperature of the hot pressing station is 700°C-900°C, the pressure of the hot pressing station is 0 MPa-1 MPa, and the temperature of the cooling station is 500°C-800°C. The conditions (such as temperature and pressure) of each preheating station, each hot pressing station, or each cooling station described in this application can be the same or different, for example, the temperature of each preheating station can be the same or different.

[0201] In some embodiments, the temperature of the preheating station is 500° C.-850° C., for example, 500° C., 600° C., 700° C., 800° C., or 850° C., or any value between these adjacent points.

[0202] In some embodiments, the temperature of the hot pressing station is 700° C.-900° C., for example, 700° C., 750° C., 800° C., 850° C., or 900° C., or any value between these adjacent points.

[0203] In some embodiments, the pressure of the hot pressing station is 0 MPa-1 MPa, for example, it can be 0 MPa, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa or 1 MPa, or any value between these adjacent point values.

[0204] In some embodiments, the temperature of the cooling station is 500° C.-800° C., for example, 500° C., 600° C., 700° C., 800° C., or 850° C., or any value between these adjacent points.

[0205] In some embodiments, the working time of the preheating station is 90s-360s, the working time of the hot pressing station is 90s-360s, and the working time of the cooling station is 90s-360s. The working time of each station is 90s-360s, for example, 90s, 100s, 110s, 150s, 200s, 250s, 300s, 350s or 360s, or any value between these adjacent point values.

[0206] The present application also provides a chemically strengthened microcrystalline glass, wherein the composition at the center of the chemically strengthened microcrystalline glass is basically the same as the composition of the 3D curved microcrystalline glass, the chemically strengthened microcrystalline glass includes a compressive stress layer region extending from the surface of the chemically strengthened microcrystalline glass to the compression depth, and has tensile stress inside the chemically strengthened microcrystalline glass.

[0207] It should be understood that after chemical strengthening treatment, the composition of the surface of the glass-ceramics may be different from the composition of the newly formed glass-ceramics (i.e., glass-ceramics that have not been chemically strengthened). This is because during the chemical strengthening treatment, ion exchange occurs on the surface of the glass-ceramics, and one type of alkali metal ion (e.g., Li + Or Na + ) are respectively replaced by larger alkali metal ions (e.g., Na + or K + ) is replaced by, such as Na in glass-ceramics + K in molten salt bath + Exchange, K + Replaced by, and / or, Li in glass-ceramics + With Na in molten salt bath + Exchange, by Na+ However, in the embodiment, the composition and phase assembly of the glass-ceramic at the center of the depth of the glass product or near the center of the depth will still have the composition and phase assembly of the newly formed glass-ceramic. That is, in the chemically strengthened glass-ceramic of the present application, the composition of the compressive stress layer formed by ion exchange on the surface may be different from the composition of the unstrengthened 3D curved glass-ceramic, while the composition at the center of the chemically strengthened glass-ceramic with tensile stress (also called tensile stress) inside will still have the composition of the unstrengthened glass-ceramic.

[0208] The chemical strengthening treatment conditions used in the preparation of chemically strengthened glass-ceramics from 3D curved glass-ceramics in this application are relatively broad, and those skilled in the art can select the conditions based on actual needs. For example, in some embodiments, the salt bath used for the chemical strengthening treatment is a mixed molten salt, the composition of which includes: 0 < NaNO3 < 100 wt%, 0 < KNO3 < 100 wt%, and 0 < LiNO3 ≤ 0.2 wt%. In some embodiments, the temperature of the salt bath used for the chemical strengthening treatment is 430°C-530°C, and the chemical strengthening treatment time is 0.5 h-15.0 h.

[0209] In some embodiments, the chemically strengthened glass-ceramics have a CS_50 of 110-200 MPa, where CS_50 refers to the compressive stress at a depth of 50 μm from the main surface of the chemically strengthened glass-ceramics. The CS_50 of the chemically strengthened glass-ceramics within the above range indicates that the compressive stress at a depth of 50 μm from the surface of the chemically strengthened glass-ceramics is high, indicating that the chemically strengthened glass-ceramics has a higher surface stress level. A higher surface compressive stress level can offset more residual energy from a drop collision, thereby ensuring excellent damage resistance.

[0210] In some embodiments, the chemically strengthened glass-ceramics has a compressive stress layer depth DOL_0 of 0.18t-0.25t, where t is the thickness of the chemically strengthened glass-ceramics. The chemically strengthened glass-ceramics having a DOL_0 within the above range indicates that the chemically strengthened glass-ceramics has a high compressive stress layer depth, which is more conducive to offsetting the energy that drives crack propagation, thereby ensuring excellent damage resistance.

[0211] In some embodiments, the chemically strengthened glass-ceramics have a |CT_AV| of 84-140 MPa, where |CT_AV| refers to the absolute value of the average tensile stress. For example, the chemically strengthened glass-ceramics have a |CT_AV| of 84-140 MPa, 85-140 MPa, 85-120 MPa, 85-100 MPa, 90-140 MPa, 100-140 MPa, or 120-140 MPa. A |CT_AV| of the chemically strengthened glass-ceramics within the above ranges indicates that the chemically strengthened glass-ceramics have a higher tensile stress level, reflecting a higher surface stress level. A higher surface compressive stress level can offset more residual energy from a drop collision, thereby ensuring excellent damage resistance.

[0212] Meeting specific stress characteristics can ensure that chemically strengthened glass-ceramics has excellent mechanical strength properties, especially excellent drop resistance.

[0213] In some embodiments, the chemically strengthened glass-ceramics having a thickness of 0.6 mm was subjected to multiple fixed-point height drop tests using 120-grit sandpaper. The fixed-point height of the test was 1.0 m. The chemically strengthened glass-ceramics broke 30 or more times, preferably 50 or more. This indicates that the chemically strengthened glass-ceramics of the present application have excellent drop resistance.

[0214] In some embodiments, the surface Na2O concentration of the chemically strengthened glass-ceramics is 5.0wt%-20.0wt%. For example, the surface Na2O concentration of the chemically strengthened glass-ceramics can be 5.0wt%, 6.0wt%, 7.0wt%, 8.0wt%, 9.0wt%, 10.0wt%, 11.0wt%, 12.0wt%, 13.0wt%, 14.0wt%, 15.0wt%, 16.0wt%, 17.0wt%, 18.0wt%, 19.0wt% or 20.0wt%, or can be a value within a numerical range consisting of any two of the above specific values ​​as endpoints. By meeting the surface Na2O concentration within the above range, it is possible to ensure that the chemically strengthened glass-ceramics has a better surface stress level and also ensure that the chemically strengthened glass-ceramics has better weather resistance and chemical durability.

[0215] The 3D curved glass-ceramics or chemically strengthened glass-ceramics with excellent optical and mechanical properties provided in this application can be used in any required glass-ceramics glass device and can be used in many applications.

[0216] The present application also provides a glass device, wherein the glass device comprises the 3D curved microcrystalline glass or the chemically strengthened microcrystalline glass.

[0217] The present application also provides an electronic device, wherein the electronic device includes the 3D curved microcrystalline glass or the chemically strengthened microcrystalline glass.

[0218] The 3D curved glass-ceramics or chemically strengthened glass-ceramics with high performance provided by this application can be used in any desired glass-ceramics glass device and can be used in many applications. For example, work surfaces, other surfaces, covers for electronic devices or electronic devices, appliance doors, floor tiles, wall panels, storage containers, etc. Other surfaces may include but are not limited to exterior wall surfaces, stair tread surfaces, column veneers, counter surfaces, etc. The types of electronic devices or electronic devices may include but are not limited to handheld, desktop-mounted, and wall-mounted. Covers may include but are not limited to mobile phone covers, mobile phone back panels, tablet computer covers, etc. Storage containers may include but are not limited to plates, beverage bottles, etc.

[0219] In some embodiments of the present application, the 3D curved glass-ceramics or chemically strengthened glass-ceramics can be of equal or unequal thickness. Those skilled in the art can select this option based on their needs. "Unequal thickness" here means that the 3D curved glass-ceramics or chemically strengthened glass-ceramics contains at least two portions of different thicknesses.

[0220] The following detailed description of the embodiments of the present application is illustrative and intended only to explain the present application and is not to be construed as limiting the present application. In the example numbers of the following tables, S refers to an example, such as S1 refers to Example 1; D refers to a comparative example, such as D1 refers to Comparative Example 1.

[0221] Example 1

[0222] (1) Preparation of Base Glass: The raw materials were prepared according to the ratios of the oxides in S1 of Table 1, and the base glass was produced using a continuous melting method to obtain base glass (bricks) with a molded size of 360 mm (length) × 180 mm (width) × 30 mm (thickness). Table 2 shows the calculated results of the relationship between the oxide contents in Table 1.

[0223] Test results of the substrate glass obtained in S1:

[0224] Ⅰ. Through observation, the substrate glass prepared in S1 is overall clear and transparent.

[0225] II. Determine the Tg and heating DSC curve of the substrate glass in S1, and record the first exothermic peak temperature T1, the second exothermic peak temperature T2 and their difference data in the heating DSC curve, as shown in Table 3 and Figure 1, respectively. No exothermic peak or endothermic peak appears under the temperature conditions not mentioned.

[0226] III. In T g -T2 temperature range, the upper limit temperature of precipitation of lithium silicate crystal phase in the substrate glass obtained by testing T max(Li2SiO3) and the upper limit temperature of the precipitation of quartz crystal phase in the matrix glass T max (SiO2), T max (Li2SiO3), T max (SiO2) are shown in Table 3, where T g is the glass transition temperature of the substrate glass.

[0227] (2) Preparation of prefabricated microcrystalline glass: Using a heat treatment roller kiln line, the base glass is subjected to a heat treatment process to produce prefabricated microcrystalline glass bricks. The heat treatment process is shown in Table 4, including a nucleation treatment and a crystallization treatment (referred to as heat treatment process C) performed in sequence. The heating rate of the heat treatment process is 10°C / min. After being taken out of the furnace, prefabricated microcrystalline glass bricks are obtained. In terms of oxide content, the composition of the obtained prefabricated microcrystalline glass is the same as that of the base glass, as shown in Table 1.

[0228] Test results of the prefabricated glass-ceramic bricks obtained in S1:

[0229] Ⅰ. Through observation, the microcrystalline glass bricks obtained in S1 are clear and transparent as a whole.

[0230] II. The crystal phase composition, crystal phase content and crystallinity of the prefabricated glass-ceramics were tested. The results are shown in Table 4.

[0231] III. The extreme values ​​of b values ​​at nine locations on the main surface of a prefabricated glass-ceramic with a test size of 360 mm (length) × 180 mm (width) × 30 mm (thickness) are shown in Table 4.

[0232] (3) Cold working the prefabricated microcrystalline glass bricks: The prefabricated microcrystalline glass bricks were cold worked, and the cold working process included shaping, slicing, CNC processing, grinding, and polishing in sequence to obtain a flat microcrystalline glass sheet with a size of 170 mm (length) × 80 mm (width) × 0.6 mm (thickness). The range of the b value at nine locations on the main surface of the obtained flat microcrystalline glass sheet and the average value of the b value at nine locations were tested. The results are shown in Table 4.

[0233] (4) Preparation of 3D curved glass-ceramics: The obtained flat glass-ceramics sheet is placed on a 3D hot bending machine for hot bending treatment to form a 3D curved glass-ceramics. The hot bending machine used in this process is divided into three temperature zones: preheating zone, hot pressing zone and slow cooling zone. The hot bending process (referred to as hot bending process C1) includes 3 preheating stations, 3 hot pressing stations and 3 cooling stations respectively; the temperatures of the 3 preheating stations are 590℃, 680℃ and 790℃ respectively, the temperatures and pressures of the 3 hot pressing stations are 790℃ / 0.4MPa, 790℃ / 0.4MPa and 790℃ / 0.2MPa respectively, and the temperatures of the 3 cooling stations are 790℃, 650℃ and 600℃ respectively; the residence time of each station is 90s. In terms of oxide content, the composition of the obtained 3D curved glass-ceramics is the same as that of the substrate glass, as shown in Table 1.

[0234] Test results of the 3D curved glass-ceramics obtained in S1:

[0235] I. The optical properties of the 3D curved glass-ceramic were tested, including the range and average of the b values ​​at nine locations on the main surface of the 3D curved glass-ceramic sample. The test results are shown in Table 4.

[0236] II. The crystal phase composition of the 3D curved glass-ceramics was tested, and the results are shown in Table 4. Calculations show that the average crystal size of the 3D curved glass-ceramics is 19 nm.

[0237] III. Testing the 3D curved glass-ceramic sheet at nine b-value locations. A comparison of the XRD diffraction curves at the maximum and minimum b-value locations is shown in Figure 10. Figure 10 shows that the crystalline structures at the maximum and minimum b-value locations on the main surface of the glass-ceramic sheet are essentially the same, or have very little difference. This indicates that the 3D curved glass-ceramic sheet is relatively uniform overall, resulting in consistent optical display effects.

[0238] IV. The transmittance of the 3D curved glass-ceramics was tested. As shown in FIG13 , it can be seen that the 3D curved glass-ceramics of the present application has high transmittance in the visible light band and excellent light transmittance.

[0239] (5) Preparation of chemically strengthened microcrystalline glass: The 3D curved microcrystalline glass with a size of 170 mm (length) × 80 mm (width) × 0.6 mm (thickness) obtained in step (4) was placed in a mixed nitrate salt bath of 70.00 wt% KNO3 + 30.00 wt% NaNO3 + 0.03 wt% LiNO3 (here it means based on the total amount of NaNO3 and KNO3 in the mixed molten salt, the mixed molten salt contains 0.03 wt% LiNO3) at 470°C and treated for 7.0 h to obtain chemically strengthened microcrystalline glass, t = 0.6 mm.

[0240] Testing of the chemically strengthened glass-ceramics obtained in S1: CS_50, |CT_AV|, and DOL_0 were measured using a stress tester. The chemically strengthened glass-ceramics were also tested for drop resistance from a fixed height of 1.0 m using 120-grit sandpaper. The test data are shown in Table 5.

[0241] Example 2 to Example 13

[0242] The hot bending process was carried out with reference to Example 1, except that the raw material composition and corresponding test results of each example were shown in Tables 1 to 5, respectively.

[0243] The 3D curved glass-ceramics of Examples 2 to 13 all meet the following requirements: the overall appearance is clear and transparent; the crystalline phases of the 3D curved glass-ceramics are mainly Li2Si2O5, LiAlSi4O 10 , there is no quartz crystal phase. According to calculations, the average crystal size in the 3D curved glass-ceramics of Examples 2 to 13 is 10-50 nm.

[0244] The XRD diffraction pattern of the substrate glass of Example 2 after heat treatment process C before hot bending is shown in Figure 8. The temperature-increasing DSC curve of the substrate glass of Example 10 is shown in Figure 2.

[0245] Comparative Example 1-Comparative Example 13

[0246] The hot bending treatment process was carried out with reference to Example 1, except that the raw material composition of each comparative example and the corresponding test results are shown in Tables 6 to 11, respectively.

[0247] Among them, the heating DSC curve of Comparative Example 1 is shown in Figure 3. The heating DSC curve of Comparative Example 2 is shown in Figure 4, and the XRD diffraction pattern obtained after the base glass of Comparative Example 2 is subjected to heat treatment process C is shown in Figure 9. In the nine b-value tests of the microcrystalline glass sheet of Comparative Example 6, the comparison of the XRD diffraction curves at the maximum b-value position and the minimum b-value position is shown in Figure 11. It can be seen from the figure that there is an obvious difference in the crystalline phase structure at the maximum b-value position and the minimum b-value position of the main surface of the 3D curved microcrystalline glass sheet, which indicates that the microstructure of different areas of the 3D curved microcrystalline glass sheet is inconsistent, which will lead to differences in its overall display effect, resulting in local color display and / or overall uneven color display on the main surface. The prefabricated microcrystalline glass of Comparative Example 7 cracked during the 3D hot bending forming process, as shown in Figure 12.

[0248] After calculation, the average crystal size in the 3D curved glass-ceramics of Comparative Examples 1 to 12 is greater than 20 nm.

[0249] Table 1

[0250] Table 2

[0251] Table 3 Note: In Table 3, “ / ” indicates that there is no SiO2 crystal phase, so there is no quartz vanishing temperature; the same applies to the corresponding tables in the comparative examples.

[0252] Table 4

[0253] Table 5 Note: “>50” in Table 5 means that the material did not break after being dropped 50 times, and the same applies to the other parts; the meanings in the corresponding tables of the comparative examples are the same.

[0254] Table 6

[0255] Table 7

[0256] Table 8

[0257] Table 9

[0258] Table 10

[0259] Table 11

[0260] It can be seen from the results of the embodiments in Tables 1 to 5 and the comparative examples in Tables 6 to 11 above that, relative to the comparative examples, the embodiment scheme of the present application, while meeting the content ranges of each oxide, also meets the following conditions: 0.180≤5×P2O5 / (Li2O+0.5Al2O3)≤0.250, 18.200≤Li2O / P2O5≤25.500, 0.100≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.200, 1.500≤ ≤10×(ZrO2+P2O5) / Li2O≤2.000、4.000≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤6.000、2.600≤99×(CaO+ZrO2) / (Li2O+Na2O+1000K2O)≤5.000、12.200≤(5.6B2O3+10Al2O3+6.5CaO) / ZrO2≤20.000. The large-scale substrate glass bricks prepared have a clear and transparent appearance, and Tmax (Li2SiO3)≥T max (SiO2) is conducive to 3D hot bending forming of 3D curved microcrystalline glass with good and uniform optical properties. The substrate glass has at least two exothermic peaks at a suitable temperature in the heating DSC curve tested by simultaneous thermal analysis.

[0261] The prefabricated microcrystalline glass bricks obtained by heat treatment of the large-size substrate glass bricks prepared by the embodiments of the present application are also transparent and clear in appearance. The b-value difference of different areas on the main surface of the prefabricated microcrystalline glass bricks is small and the uniformity is good. In addition, the prefabricated microcrystalline glass does not contain quartz crystal phase. In the 3D curved microcrystalline glass prepared by heat bending the prefabricated microcrystalline glass, the range of the b-values ​​at nine locations on the main surface is low and the average b-value is also low, which indicates that the 3D curved microcrystalline glass has excellent optical properties and good display effects. At the same time, the obtained 3D curved microcrystalline glass is chemically strengthened to obtain chemically strengthened microcrystalline glass with higher CS_50, |CT_AV|, and DOL_0.

[0262] In the solutions of Comparative Examples 1 to 8 and 12, the formula of the substrate glass does not meet the following requirements: the content range of each oxide in the present application, as well as 0.180≤5×P2O5 / (Li2O+0.5Al2O3)≤0.250, 18.200≤Li2O / P2O5≤25.500, 0.100≤P2O5×(CaO+ZrO2+Li2O+Al2O3) / (Na2O+K2O+B2O3)≤2.200, 1 .500≤10×(ZrO2+P2O5) / Li2O≤2.000, 4.000≤(SiO2-7Al2O3-Li2O) / (P2O5+ZrO2)≤6.000, 2.600≤99×(CaO+ZrO2) / (Li2O+Na2O+1000K2O)≤5.000, 12.200≤(5.6B2O3+10Al2O3+6.5CaO) / ZrO2≤20.000. When the large-scale substrate glass bricks prepared by these schemes are heat-treated to prepare large-scale prefabricated micro-ceramic bricks, the b-values ​​of different areas on the main surface of the prefabricated micro-ceramic bricks vary greatly, and this large difference is carried over to the 3D curved micro-ceramic obtained by hot bending, resulting in poor optical performance, causing the display effect of the 3D curved micro-ceramic to not meet the use requirements and even cracking.

[0263] In Comparative Examples 9 and 10, after the large-scale substrate glass bricks were prepared, a milky white precipitate appeared directly in the substrate glass bricks, resulting in deteriorated optical properties and reduced transmittance. In Comparative Examples 11 and 12, the mass-produced glass-ceramics failed to achieve the required excellent mechanical properties after chemical strengthening, and their drop resistance was significantly inferior to that of the products of the present application. In Comparative Example 13, a milky white precipitate and undissolved matter appeared in the large-scale substrate glass bricks prepared.

[0264] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, including combining the various technical features in any other appropriate manner. These simple modifications and combinations should also be regarded as the contents disclosed in the present application and fall within the scope of protection of the present application. Industrial Applicability

[0265] By ensuring that the content of each oxide is within an appropriate range and coordinating the oxide content ratio under specific conditions, the present application can ensure the generation of the main crystalline phase during the mass production of 3D curved microcrystalline glass products. At the same time, it can ensure that the prepared 3D curved microcrystalline glass products present a relatively uniform display effect as a whole, effectively avoiding the problem of large differences in b values ​​in different areas of 3D curved microcrystalline glass products prepared in mass production, resulting in poor display effects.

[0266] The large-sized substrate glass bricks prepared by the glass solution of the present application can ensure that the overall b value of the main surface of the prefabricated microcrystalline glass bricks is close when they are heat-treated to be prepared into prefabricated microcrystalline glass bricks, thereby ensuring that the 3D curved microcrystalline glass prepared therefrom also presents a good display effect. The specific composition scheme of the present application can ensure that 3D curved microcrystalline glass with good optical performance is obtained, which is conducive to the industrial mass production of 3D curved microcrystalline glass and the improvement of the yield of 3D curved microcrystalline glass products. At the same time, the microcrystalline glass prepared by the above-mentioned substrate glass formula scheme can be prepared by chemical strengthening to obtain chemically strengthened microcrystalline glass with excellent strength properties, especially anti-drop performance. In the mass production process of 3D curved microcrystalline glass with the main crystal phases of petalite and lithium disilicate, products with poor optical display basically have a quartz (SiO2) impurity phase. The present application adjusts the composition scheme of the substrate glass so that the substrate glass has an upper limit temperature T for precipitation of the quartz crystal phase within a specific temperature range. max (SiO2) is lower than the upper limit temperature T of the precipitation of lithium silicate crystal phase max(Li2SiO3) can ensure that the substrate glass can effectively avoid the precipitation of quartz crystal phase under specific heat treatment process conditions for preparing prefabricated microcrystalline glass with main crystal phases of petalite and lithium disilicate. Combined with the subsequent hot bending process, the lithium monosilicate crystal phase can also be transformed into the required lithium disilicate crystal phase, thereby avoiding the adverse effects of the quartz crystal phase and the lithium monosilicate crystal phase on the optical effect of the glass.

Claims

1. A 3D curved surface microcrystalline glass, characterized in that, The 3D curved surface microcrystalline glass contains spodumene crystal phase and lithium disilicate crystal phase, and the spodumene crystal phase and lithium disilicate crystal phase have a higher weight percentage than other crystal phases present in the 3D curved surface microcrystalline glass; In terms of the molar percentage of oxides, the composition of the 3D curved surface microcrystalline glass includes: SiO2: 60.00 mol% - 71.00 mol%, Al2O3: 1.50 mol% - 5.00 mol%, P2O5: 0.80 mol% - 1.50 mol%, ZrO2: 2.00 mol% - 4.00 mol%, Na2O: 0.00 mol% - 1.00 mol%, K2O: 0.00 mol% - 0.50 mol%, Li2O: 20.00 mol% - 30.00 mol%, CaO: 0.00 mol% - 1.60 mol%, B2O3: 0.00 mol% - 1.00 mol%; Based on the content expressed as the molar percentage of each oxide in the composition of the 3D curved surface microcrystalline glass, the composition of the 3D curved surface microcrystalline glass satisfies: 0.180 ≤ 5×P2O5 / (Li2O + 0.5Al2O3) ≤ 0.250; 18.200 ≤ Li2O / P2O5 ≤ 25.500; 0.100 ≤ P2O5×(CaO + ZrO2 + Li2O + Al2O3) / (Na2O + K2O + B2O3) ≤ 2.200; 1.500 ≤ 10×(ZrO2 + P2O5) / Li2O ≤ 2.000; 4.000 ≤ (SiO2 - 7Al2O3 - Li2O) / (P2O5 + ZrO2) ≤ 6.000; 2.600 ≤ 99×(CaO + ZrO2) / (Li2O + Na2O + 1000K2O) ≤ 5.000; 12.200 ≤ (5.6B2O3 + 10Al2O3 + 6.5CaO) / ZrO2 ≤ 20.

000.

2. The 3D curved surface microcrystalline glass according to claim 1, wherein The 3D curved surface microcrystalline glass is transparent in the visible light range.

3. The 3D curved surface microcrystalline glass according to any one of claims 1-2, characterized in that In terms of the molar percentage of oxides, the composition of the 3D curved surface microcrystalline glass includes: SiO2: 67.50 mol% - 71.00 mol%, Al2O3: 3.50 mol% - 5.00 mol%, P2O5: not less than 0.85 mol% and less than 1.50 mol%, ZrO2: 2.50 mol% - 3.50 mol%, Na2O: greater than 0.00 mol% and not greater than 1.00 mol%, K2O: greater than 0.00 mol% and not greater than 0.50 mol%, Li2O: 20.00 mol% - 25.00 mol%, CaO: greater than 0.50 mol% and not greater than 1.50 mol%, B2O3: 0.00 mol% - 1.00 mol%.

4. The 3D curved surface microcrystalline glass according to any one of claims 1-3, wherein The 3D curved surface microcrystalline glass does not contain quartz crystal phase.

5. The 3D curved surface microcrystalline glass according to any one of claims 1-4, characterized in that, In the 3D curved surface microcrystalline glass, the total content of spodumene crystal phase and lithium disilicate crystal phase accounts for more than 60.00 wt% of the mass of the 3D curved surface microcrystalline glass, preferably more than 70.00 wt%, and more preferably more than 80.00 wt%; in the 3D curved surface microcrystalline glass, the average crystal size does not exceed 100 nm.

6. The 3D curved surface microcrystalline glass according to any one of claims 1-5, wherein Based on the content expressed in mole percentages of each oxide in the composition of the 3D curved surface microcrystalline glass, the composition of the microcrystalline glass satisfies: 0.184 ≤ 5×P2O5 / (Li2O + 0.5Al2O3) ≤ 0.245; and / or 18.200 ≤ Li2O / P2O5 ≤ 25.000; and / or 0.190 ≤ P2O5×(CaO + ZrO2 + Li2O + Al2O3) / (Na2O + K2O + B2O3) ≤ 2.180; and / or 1.500 ≤ 10×(ZrO2 + P2O5) / Li2O ≤ 1.900; and / or 4.200 ≤ (SiO2 - 7Al2O3 - Li2O) / (P2O5 + ZrO2) ≤ 5.900; and / or 2.600 ≤ 99×(CaO + ZrO2) / (Li2O + Na2O + 1000K2O) ≤ 4.950; and / or 15.000 ≤ (5.6B2O3 + 10Al2O3 + 6.5CaO) / ZrO2 ≤ 20.

000.

7. The 3D curved surface microcrystalline glass according to any one of claims 1-6, characterized in that, Based on the content expressed in mole percentages of each oxide in the composition of the 3D curved surface microcrystalline glass, the composition of the 3D curved surface microcrystalline glass satisfies: 0.186 ≤ 5×P2O5 / (Li2O + 0.5Al2O3) ≤ 0.243; and / or 18.500 ≤ Li2O / P2O5 ≤ 24.700; and / or 0.190 ≤ P2O5×(CaO + ZrO2 + Li2O + Al2O3) / (Na2O + K2O + B2O3) ≤ 2.170; and / or 1.550 ≤ 10×(ZrO2 + P2O5) / Li2O ≤ 1.850; and / or 4.600 ≤ (SiO2 - 7Al2O3 - Li2O) / (P2O5 + ZrO2) ≤ 5.850; and / or 2.680 ≤ 99×(CaO + ZrO2) / (Li2O + Na2O + 1000K2O) ≤ 4.930; and / or 16.000 ≤ (5.6B2O3 + 10Al2O3 + 6.5CaO) / ZrO2 ≤ 20.

000.

8. The 3D curved surface microcrystalline glass according to any one of claims 1-7, characterized in that When the thickness is 0.6 mm, the optical b value of the 3D curved surface microcrystalline glass ≤ 1.00, preferably the optical b value ≤ 0.70, and more preferably the optical b value ≤ 0.

55.

9. The 3D curved surface microcrystalline glass according to any one of claims 1-8, characterized in that When the thickness is 0.6 mm, the range of the b values at nine positions on the main surface of the 3D curved surface microcrystalline glass ≤ 0.30, preferably the range of the b values at nine positions on the main surface ≤ 0.10, and preferably the range of the b values at nine positions on the main surface ≤ 0.06; Among them, the positions of the nine places are respectively: (1) the test positions of the test circles Ⅰ near the four corners of the main surface, a total of four places; (2) the test positions of the four test circles Ⅱ formed with the points closest to the middle of the long side or the short side of the main surface on the line segments formed by the centers of the above four test circles Ⅰ, a total of four places; (3) the position of the test circle Ⅲ formed with the center point of the main surface as the center of the circle.

10. The 3D curved surface microcrystalline glass according to any one of claims 1-9, characterized in that, When the thickness of the 3D curved surface microcrystalline glass is 0.6 mm, the haze is ≤ 0.20%, and under the light with a wavelength of 550 nm, the transmittance of the microcrystalline glass is ≥ 90.00%.

11. A substrate glass, which can be used to prepare the 3D curved surface microcrystalline glass according to any one of claims 1-10, characterized in that, Calculated in terms of the molar percentage of oxides, the composition of the base glass includes: SiO2: 60.00 mol% - 71.00 mol%, Al2O3: 1.50 mol% - 5.00 mol%, P2O5: 0.80 mol% - 1.50 mol%, ZrO2: 2.00 mol% - 4.00 mol%, Na2O: 0.00 mol% - 1.00 mol%, K2O: 0.00 mol% - 0.50 mol%, Li2O: 20.00 mol% - 30.00 mol%, CaO: 0.00 mol% - 1.60 mol%, B2O3: 0.00 mol% - 1.00 mol%; Calculated based on the content expressed in the molar percentage of each oxide in the composition of the base glass, the composition of the base glass satisfies: 0.180 ≤ 5 × P2O5 / (Li2O + 0.5Al2O3) ≤ 0.250; 18.200 ≤ Li2O / P2O5 ≤ 25.500; 0.100 ≤ P2O5 × (CaO + ZrO2 + Li2O + Al2O3) / (Na2O + K2O + B2O3) ≤ 2.200; 1.500 ≤ 10 × (ZrO2 + P2O5) / Li2O ≤ 2.000; 4.000 ≤ (SiO2 - 7Al2O3 - Li2O) / (P2O5 + ZrO2) ≤ 6.000; 2.600 ≤ 99 × (CaO + ZrO2) / (Li2O + Na2O + 1000K2O) ≤ 5.000; 12.200 ≤ (5.6B2O3 + 10Al2O3 + 6.5CaO) / ZrO2 ≤ 20.

000.

12. The substrate glass according to claim 11, wherein: Through synchronous thermal analysis test, under the protective atmosphere of nitrogen, the base glass is heated from room temperature to 900 °C at a heating rate of 10 °C / min to obtain a heating DSC curve. In this heating DSC curve, there are at least two exothermic peaks. Among them, the temperature T1 of the first exothermic peak is 600 °C - 730 °C, the temperature T2 of the second exothermic peak is 740 °C - 800 °C, and T1 and T2 satisfy the relationship: 100 °C ≥ T2 - T1 ≥ 40 °C, preferably 80 °C ≥ T2 - T1 ≥ 50 °C.

13. The base glass according to claim 12, wherein: At temperature T g -T2, the upper limit temperature T max (Li2SiO3) of the precipitation of the lithium metasilicate crystal phase in the substrate glass and the upper limit temperature T max (SiO2) of the precipitation of the quartz crystal phase in the substrate glass are tested. T max (Li2SiO3) ≥ T max (SiO2), where T g is the glass transition temperature of the substrate glass.

14. The base glass according to any one of claims 11-13, characterized in that, In terms of molar percentage of oxides, the composition of the base glass includes: SiO2: 67.50 mol% - 71.00 mol%, Al2O3: 3.50 mol% - 5.00 mol%, P2O5: not less than 0.85 mol% and less than 1.50 mol%, ZrO2: 2.50 mol% - 3.50 mol%, Na2O: greater than 0.00 mol% and not greater than 1.00 mol%, K2O: greater than 0.00 mol% and not greater than 0.50 mol%, Li2O: 20.00 mol% - 25.00 mol%, CaO: greater than 0.50 mol% and not greater than 1.50 mol%, B2O3: 0.00 mol% - 1.00 mol%.

15. A method for preparing a 3D curved surface microcrystalline glass according to any one of claims 1-10, characterized in that, It includes the following steps: (1) Heat-treat the base glass as described in any one of claims 11 - 14 to obtain a prefabricated glass-ceramic product containing a lithium metasilicate crystal phase, a lithium disilicate crystal phase, and a spodumene crystal phase, and having a crystallinity of not less than 60.00 wt%. (2) Process the prefabricated glass-ceramic product obtained in step (1) into a planar glass-ceramic sheet with the required specification dimensions, and perform a hot bending treatment on the obtained planar glass-ceramic sheet to obtain a 3D curved glass-ceramic. The 3D curved glass-ceramic contains a spodumene crystal phase and a lithium disilicate crystal phase, and the spodumene crystal phase and the lithium disilicate crystal phase have a higher weight percentage than other crystal phases present in the 3D curved glass-ceramic.

16. The method for preparing the 3D curved surface microcrystalline glass according to claim 15, wherein, In step (1), the heat treatment includes a nucleation treatment and a crystallization treatment. Among them, the temperature of the nucleation treatment is (Tg - 20°C) to (Tg + 40°C), the time of the nucleation treatment is 0 min - 6000 min, the temperature of the crystallization treatment is (T1 - 50°C) to T1, and the time of the crystallization treatment is 30 min - 6000 min; Tg is the glass transition temperature of the base glass; in step (1), the heating rate of the heat treatment process is 5°C / min - 15°C / min.

17. The method for preparing the 3D curved surface microcrystalline glass according to claim 15 or 16, characterized in that, In step (2), the hot bending treatment process includes at least 3 preheating stations, at least 3 hot pressing stations, and at least 3 cooling stations; the temperature of the preheating stations is 500°C - 850°C, the temperature of the hot pressing stations is 700°C - 900°C, the pressure of the hot pressing stations is 0 MPa - 1 MPa, and the temperature of the cooling stations is 500°C - 800°C; Preferably, the working time of each preheating station is 90 s - 360 s, the working time of each hot pressing station is 90 s - 360 s, and the working time of each cooling station is 90 s - 360 s.

18. A chemically strengthened microcrystalline glass, characterized in that, The composition at the center of the chemically strengthened glass-ceramic is the same as that of the 3D curved glass-ceramic as described in any one of claims 1 - 10. The chemically strengthened glass-ceramic contains a compressive stress layer region extending from the surface of the chemically strengthened glass-ceramic to the compression depth, and has a tensile stress inside the chemically strengthened glass-ceramic.

19. A glass device, characterized in that, The glass device comprises the 3D curved surface microcrystalline glass as described in any one of claims 1-10 or comprises the chemically strengthened microcrystalline glass as described in claim 17.

20. An electronic device, characterized in that, The electronic device includes the 3D curved surface microcrystalline glass as described in any one of claims 1-10 or comprises the chemically strengthened microcrystalline glass as described in claim 17.

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