A chemically strengthened glass and a glass device comprising the chemically strengthened glass

Abstract

The present application provides a chemically strengthened glass and a glass device including the chemically strengthened glass. The chemically strengthened glass meets the following conditions: the compressive stress line density CT_LD of the chemically strengthened glass is greater than or equal to 40000 MPa / mm, and the ratio of CT_LD / S is greater than or equal to 7.5 and less than or equal to 20. Thus, the obtained chemically strengthened glass has excellent drop resistance. Moreover, during the preparation process of the chemically strengthened glass, the content of lithium ions released by the glass into the salt bath is less than that of the existing lithium aluminosilicate glass, which is not only beneficial to improving the service life of the salt bath but also ensures that the mass-produced chemically strengthened glass has relatively stable drop resistance.

Description

Technical Field

[0001] The present application relates to the technical field of glass, and particularly to a chemically strengthened glass and a glass device including the chemically strengthened glass. Background Art

[0002] In recent years, lithium aluminosilicate chemically strengthened glass has been widely used for the display protection cover and the back cover of mobile phones. With the update and iteration of smart phones, mobile phone manufacturers have higher and higher requirements for the anti-drop performance of cover glass. The anti-drop performance of existing lithium aluminosilicate glass products still has deficiencies. In the face of the high requirements for anti-drop performance in the market, some products achieve an increase in the anti-drop height by performing a large amount of ion exchange, that is, by increasing the ion exchange amount to obtain a sufficient stress level to increase the anti-drop height. However, when the ion exchange amount is large, on the one hand, it is easy to cause excessive volume change on the surface layer of the substrate glass after strengthening, resulting in a large dispersion in the anti-drop height distribution of samples in the same batch, increasing the probability of having a low anti-drop height in the samples of the same batch, and thus making the anti-drop performance of the mass-produced chemically strengthened glass extremely unstable. At the same time, a large ion exchange amount also means that during the preparation of the chemically strengthened glass, a large amount of lithium ions are released from the glass into the salt bath, which will shorten the service life of the salt bath, and thus increase the manufacturing cost of the lithium aluminosilicate chemically strengthened glass, especially the strengthening cost.

[0003] Therefore, developing a chemically strengthened glass that can reduce the manufacturing cost, has improved anti-drop performance, and ensures that the mass-produced chemically strengthened glass has relatively stable anti-drop performance will greatly improve the competitiveness of products. Summary of the Invention

[0004] The purpose of the present application is to provide a chemically strengthened glass with improved anti-drop performance and ensure that the mass-produced chemically strengthened glass has relatively stable anti-drop performance. The specific technical solutions are as follows:

[0005] The first aspect of the present application provides a chemically strengthened glass, which satisfies the following conditions: the compressive stress line density CT_LD of the chemically strengthened glass is greater than or equal to 40000 MPa / mm, and the ratio of CT_LD / S is greater than or equal to 7.5 and less than or equal to 20; the chemically strengthened glass includes a compressive stress layer on the surface of the chemically strengthened glass and a tensile stress layer inside the chemically strengthened glass. By testing the signal intensity distribution curve of the sodium element content of the chemically strengthened glass along the thickness direction with an X-ray energy spectrometer, fitting the signal intensity distribution curve into a smooth curve, the area of the figure enclosed by x = x1, x = x2, y = y0 and the smooth curve is S, x1 is the test depth value corresponding to the surface of the chemically strengthened glass, x2 is the test depth value corresponding to the position where the compressive stress is zero, and y0 is the intensity value corresponding to the sodium element content in the tensile stress layer in the smooth curve.

[0006] In some embodiments of the present application, the surface CS of the chemically strengthened glass is greater than or equal to 900 MPa and less than or equal to 1600 MPa, preferably greater than or equal to 1000 MPa and less than or equal to 1600 MPa.

[0007] In some embodiments of the present application, the depth of the compressive stress layer DOL_0 of the chemically strengthened glass is 0.15t - 0.22t, where t is the thickness of the chemically strengthened glass.

[0008] In some embodiments of the present application, the Young's modulus of the chemically strengthened glass is greater than or equal to 85 GPa, preferably greater than or equal to 90 GPa.

[0009] In some embodiments of the present application, the compressive stress line density CT_LD of the chemically strengthened glass is greater than or equal to 42000 MPa / mm and less than or equal to 70000 MPa / mm, preferably greater than or equal to 43000 MPa / mm and less than or equal to 70000 MPa / mm.

[0010] In some embodiments of the present application, expressed in terms of the molar percentage of oxides, the composition of the tensile stress layer of the chemically strengthened glass includes: SiO2 60.00 - 75.00 mol%, Al2O3 8.00 - 18.00 mol%, Li2O 7.00 - 12.00 mol%, Y2O3 0 - 10.00 mol%, Na2O 2.00 - 8.00 mol%, MgO 0 - 8.00 mol%.

[0011] In some embodiments of the present application, expressed in terms of the molar percentage of oxides, the composition of the tensile stress layer of the chemically strengthened glass further includes: B2O3 0 - 5.00 mol%, preferably B2O3 0 - 3.00 mol%.

[0012] In some embodiments of the present application, expressed in mole percentages of oxides, the composition of the compressive stress layer of the chemically strengthened glass comprises: SiO2 60.00 - 75.00 mol%, Al2O3 8.00 - 12.00 mol%, Li2O 7.00 - 12.00 mol%, Y2O3 1.00 - 3.00 mol%, Na2O 2.00 - 8.00 mol%, MgO 0 - 8.00 mol%, La2O3 0.10 - 3.00 mol%.

[0013] In some embodiments of the present application, expressed in mole percentages of oxides, the composition in the compressive stress layer of the chemically strengthened glass satisfies: La2O3 / Y2O3 is 0.2 - 1.0; and / or

[0014] Al2O3 + Li2O ≤ 22.00 mol%, preferably, Al2O3 + Li2O ≤ 20.00 mol%.

[0015] In some embodiments of the present application, expressed in mole percentages of oxides, the composition of the compressive stress layer of the chemically strengthened glass further comprises: SrO 0 - 3.00 mol%, SrO / (MgO + SrO) ≤ 0.35; and / or K2O 0 - 3.00 mol%.

[0016] In some embodiments of the present application, expressed in mole percentages of oxides, SrO / (MgO + SrO) ≤ 0.35.

[0017] In some embodiments of the present application, expressed in mole percentages of oxides, the composition of the compressive stress layer of the chemically strengthened glass comprises: SiO2 60.00 - 75.00 mol%, Al2O3 8.00 - 12.00 mol%, Li2O 7.00 - 12.00 mol%, Y2O3 1.00 - 3.00 mol%, Na2O 2.00 - 8.00 mol%, MgO 1.00 - 8.00 mol%, La2O3 0.20 - 1.50 mol.

[0018] In some embodiments of the present application, expressed in mole percentages of oxides, the composition of the compressive stress layer of the chemically strengthened glass satisfies: SiO2 64.00 - 70.00 mol% and / or Li2O 8.00 - 12.00 mol% and / or Na2O 4.00 - 6.00 mol% and / or MgO 2.00 - 7.50 mol% and / or La2O3 0.20 - 1.50 mol%.

[0019] In some embodiments of the present application, the composition of the substrate glass, expressed as mole percentages of oxides, comprises: SiO2 60.00 - 75.00 mol%, Al2O3 8.00 - 12.00 mol%, Li2O 7.00 - 12.00 mol%, Y2O3 1.00 - 3.00 mol%, Na2O 2.00 - 8.00 mol%, MgO 1.00 - 8.00 mol%, La2O3 0.20 - 3.00 mol%, and La2O3 / Y2O3 is 0.2 - 1.0.

[0020] In some embodiments of the present application, the composition of the substrate glass, expressed as mole percentages of oxides, comprises: SiO2 64.00 - 70.00 mol%, Al2O3 8.00 - 12.00 mol%, Li2O 8.00 - 12.00 mol%, Y2O3 1.00 - 3.00 mol%, Na2O 4.00 - 6.00 mol%, MgO 2.00 - 7.50 mol%, La2O3 0.20 - 1.50 mol%.

[0021] In some embodiments of the present application, for the chemically strengthened glass with a thickness of 0.7 mm, the anti-drop test is carried out using 120 - mesh sandpaper, and the average anti - sandpaper drop height is greater than or equal to 1.60 m, preferably greater than or equal to 1.70 m.

[0022] In some embodiments of the present application, for the chemically strengthened glass with a thickness of 0.7 mm, the anti-drop test is carried out using 120 - mesh sandpaper, and the B10 value of the anti - sandpaper drop height is greater than or equal to 1.1 m, preferably 1.1 - 2.0 m.

[0023] In some embodiments of the present application, for the chemically strengthened glass with a thickness of 0.7 mm, the reduction of the B10 value of the anti - sandpaper drop height compared to the average anti - sandpaper drop height does not exceed 25%, and the sandpaper mesh number used in the test is 120 mesh.

[0024] The second aspect of the present application provides a glass device, which is made of the chemically strengthened glass in any of the above - mentioned embodiments.

[0025] The third aspect of the present application provides an electronic device, which includes the chemically strengthened glass in any of the above - mentioned embodiments.

[0026] In some embodiments of the present application, the electronic device includes a mobile phone, a tablet computer, smart wearables, a display, or a television. Among them, smart wearables include smart bracelets, smart watches, smart glasses, etc., and displays include high - definition displays, in - vehicle displays, on - vehicle displays, etc.

[0027] Any one of the above - mentioned technical solutions has the following beneficial effects:

[0028] This application provides a chemically strengthened glass with improved drop resistance. When preparing this chemically strengthened glass, the content of lithium ions released into the salt bath is less than that of the existing lithium aluminosilicate glass, which is beneficial to improving the service life of the salt bath and reducing the strengthening cost. Moreover, the reduction of the ion exchange amount is beneficial to reducing the discreteness of the drop resistance height distribution of batch samples, ensuring that the mass-produced chemically strengthened glass has relatively stable drop resistance performance.

[0029] Of course, it is not necessary for any product or method implementing this application to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of this application, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of this application, and those of ordinary skill in the art can also obtain other embodiments based on these drawings.

[0031] Figure 1 Schematic diagram of the chemically strengthened glass in Example 3 tested by a Bruker EDS - X - ray energy spectrometer;

[0032] Figure 2 Signal intensity distribution curve corresponding to the sodium element content of the chemically strengthened glass in Example 3;

[0033] Figure 3 For Figure 2 The smooth curve obtained by fitting the signal intensity distribution curve in;

[0034] Figure 4 Schematic diagram of the temperature distribution of the long quartz trough in the upper limit temperature of crystallization test;

[0035] Figure 5 Sample diagram in the long quartz trough after the upper limit temperature of crystallization test. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are only some, rather than all, of the embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art based on this application belong to the scope of protection of this application.

[0037] TERMINOLOGY EXPLANATION

[0038] Chemically strengthened glass: It is strengthened glass processed by a high-temperature ion exchange process. In a high-temperature salt bath, alkali metal ions with a large ionic radius replace alkali metal ions with a small ionic radius in the glass, resulting in a difference in the volume of the exchanged ions. A compressive stress from high to low is generated from the surface to the inside of the surface layer of the substrate glass, hindering and delaying the expansion of glass microcracks, thereby achieving the purpose of improving the mechanical strength of the glass.

[0039] Substrate glass: It is the glass matrix material that has not been strengthened.

[0040] Surface CS: Surface compressive stress / surface compression stress. After the glass is chemically strengthened, alkali metal ions with a smaller radius on the surface are replaced by alkali metal ions with a larger radius. Due to the jamming effect of alkali metal ions with a larger radius, a compressive stress is generated on the glass surface. Measured by the stress meter FSM-6000 of Orihara in Japan.

[0041] 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 where the compressive stress near that surface is zero. Measured by the stress meter SLP-2000 of Orihara in Japan.

[0042] CT_LD: Tensile stress line density. The ratio of the definite integral of the tensile stress curve of the strengthened glass to the thickness of the strengthened glass is denoted as the tensile stress line density. The substrate glass is placed in a salt bath for ion exchange to form a strengthened layer (compressive stress layer / stress layer). During the ion exchange process, a tensile stress layer is formed inside the glass. The tensile stress layer has an upper boundary at a certain interval from the upper surface of the chemically strengthened glass and a lower boundary at a certain interval from the lower surface of the chemically strengthened glass. The curve plotted with the magnitude of the tensile stress at a certain point on the line segment that is perpendicular to both the upper boundary and the lower boundary and whose upper and lower endpoints fall on the upper boundary and the lower boundary respectively in the tensile stress layer as the Y-axis and the distance from the corresponding point to the upper boundary as the X-axis is denoted as the tensile stress curve. The ratio of the definite integral of the tensile stress curve to the thickness of the strengthened glass is denoted as the tensile stress line density. That is, it is the ratio of the sum of the tensile stresses of the strengthened glass measured by the SLP-2000 stress meter to the thickness of the glass.

[0043] CT_LD max : The maximum value of the tensile stress line density (CT_LD) that the substrate glass can obtain through ion exchange chemical strengthening under specific salt bath conditions, that is, the maximum value of the tensile stress line density CT_LD that the substrate glass can obtain under this salt bath condition. max This data can characterize the strengthenable performance / ion exchange performance of the substrate glass.

[0044] During the chemical strengthening process, as the strengthening time increases, the value of the compressive stress line density (CT_LD) obtained by the substrate glass will first increase and then decrease. By continuously monitoring the change of the compressive stress line density inside the glass during the strengthening process, the maximum value of the compressive stress line density CT_LD that can be obtained by strengthening under specific salt bath conditions can be determined. max 。

[0045] The inventors of the present application have found through research that when existing lithium aluminosilicate chemically strengthened glass is subjected to chemical strengthening treatment, a large amount of sodium ions and lithium ions often need to be exchanged. By introducing a large amount of sodium ions into the substrate glass, a high stress level can be achieved, or a large amount of sodium ions will be introduced into the glass due to over-strengthening. When the amount of sodium ion and lithium ion exchange is large, it is easy to cause excessive volume change on the glass surface layer. When the volume change inside the glass is small, it is easy to cause the expansion of the microcracks originally existing on the glass surface, resulting in a large discreteness in the drop resistance height distribution of mass-produced chemically strengthened glass, increasing the probability of samples with low drop resistance height in the same batch, and further leading to extremely unstable drop resistance performance of mass-produced chemically strengthened glass, affecting the use experience of the final product. At the same time, achieving a high stress level through a large amount of sodium-lithium exchange will also cause an excessive amount of lithium ions to precipitate into the salt bath, resulting in a reduction in the salt bath life and an increase in the production cost of mass production.

[0046] Based on the above problems, the present application provides a chemically strengthened glass, as well as a glass device and an electronic device including the chemically strengthened glass. In the present application, the ion exchange stress effect refers to the stress effect generated when the same number of ions are exchanged during the ion exchange process of the substrate glass during chemical strengthening treatment. Different glass structures result in different ion exchange stress effects. Generally speaking, the higher the ion exchange stress effect, the less ion exchange amount is required to obtain a high level of stress.

[0047] The first aspect of the present application provides a chemically strengthened glass, which satisfies the following conditions: the compressive stress line density CT_LD of the chemically strengthened glass is greater than or equal to 40000 MPa / mm, preferably the compressive stress line density CT_LD is greater than or equal to 42000 MPa / mm and less than or equal to 70000 MPa / mm, and more preferably the compressive stress line density CT_LD is greater than or equal to 43000 MPa / mm and less than or equal to 70000 MPa / mm; the value of CT_LD / S is greater than or equal to 7.5 and less than or equal to 20; the chemically strengthened glass includes a compressive stress layer on the surface of the chemically strengthened glass and a tensile stress layer inside the chemically strengthened glass. By testing the signal intensity distribution curve of the sodium element content of the chemically strengthened glass in the thickness direction with an X-ray energy spectrometer, fitting the signal intensity distribution curve into a smooth curve, the area of the figure enclosed by x = x1, x = x2, y = y0 and the smooth curve is S, x1 is the test depth value corresponding to the surface of the chemically strengthened glass, x2 is the test depth value corresponding to the zero compressive stress, and y0 is the intensity value corresponding to the sodium element content in the tensile stress layer in the smooth curve.

[0048] In the present application, by controlling the chemically strengthened glass to meet specific stress design requirements, that is, the values of the compressive stress line density CT_LD and CT_LD / S are within the above ranges. For example, the compressive stress line density CT_LD can be 40000 MPa / mm, 42000 MPa / mm, 43000 MPa / mm, 45000 MPa / mm, 50000 MPa / mm, 55000 MPa / mm, 60000 MPa / mm, 65000 MPa / mm, 70000 MPa / mm or a value within the numerical range formed by any two of the above values as endpoints, and the ratio of CT_LD / S can be 7.5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or a value within the numerical range formed by any two of the above values as endpoints. The obtained chemically strengthened glass has excellent drop resistance. Among them, the range of S can be 3000 - 6500.

[0049] In some embodiments of the present application, the surface CS of the chemically strengthened glass is greater than or equal to 900 MPa and less than or equal to 1600 MPa, preferably greater than or equal to 1000 MPa and less than or equal to 1600 MPa. For example, the surface CS of the chemically strengthened glass can be 900 MPa, 950 MPa, 1000 MPa, 1050 MPa, 1100 MPa, 1150 MPa, 1200 MPa, 1250 MPa, 1300 MPa, 1350 MPa, 1400 MPa, 1450 MPa, 1500 MPa, 1550 MPa, 1600 MPa or a value within the numerical range formed by any two of the above values, indicating that the chemically strengthened glass provided by the present application has excellent scratch resistance, deformation resistance and other properties.

[0050] The present application controls the chemically strengthened glass to meet specific stress design requirements, that is, controls the stress characteristics to meet: the tensile stress line density CT_LD is greater than or equal to 40000 MPa / mm, and CT_LD / S is greater than or equal to 7.5 and less than or equal to 20. While ensuring excellent drop resistance of the chemically strengthened glass, the strengthening cost can be reduced, and the discreteness of the drop height distribution of the chemically strengthened glass of the same batch can be improved.

[0051] In some embodiments of the present application, the depth DOL_0 of the compressive stress layer of the chemically strengthened glass is 0.15t - 0.22t, where t is the thickness of the chemically strengthened glass. For example, the depth DOL_0 of the compressive stress layer can be 0.15t, 0.16t, 0.17t, 0.18t, 0.19t, 0.20t, 0.21t, 0.22t or within the range formed by any two of these values. Before and after chemical strengthening, the thickness change of the glass is very small and can be almost ignored. The depth DOL_0 of the compressive stress layer is obtained by testing with an SLP-2000 stress meter. When the depth DOL_0 of the compressive stress layer is within the above range, the compressive stress layer is deep enough. When the glass contacts a sharp object, this compressive stress layer can better prevent the generated cracks from entering the tensile stress layer, thus being beneficial to improving the drop resistance. Among them, the thickness t of the substrate glass can be selected according to the required thickness of the chemically strengthened glass, and the present application does not limit this. Exemplarily, the thickness of the substrate glass can be 0.4 - 2.0 mm.

[0052] In some embodiments of the present application, the Young's modulus of the chemically strengthened glass is greater than or equal to 85 GPa, preferably greater than or equal to 90 GPa. For example, the Young's modulus of the chemically strengthened glass can be 85 GPa, 86 GPa, 87 GPa, 88 GPa, 89 GPa, 90 GPa, 95 GPa, 100 GPa or a value within the numerical range formed by any two of the above values. It shows that the chemically strengthened glass provided by the present application has a high Young's modulus.

[0053] In some embodiments of the present application, in terms of molar percentage of oxides, the composition of the surface compression stress layer of the chemically strengthened glass comprises: SiO2 60.00 - 75.00 mol%, Al2O3 8.00 - 18.00 mol%, Li2O 7.00 - 12.00 mol%, Y2O3 0 - 10.00 mol%, Na2O 2.00 - 8.00 mol%, MgO 0 - 8.00 mol%.

[0054] During chemical strengthening, ions with a large radius in the salt bath are exchanged with ions with a small radius in the glass, thereby forming a surface compression stress layer on the glass surface and a surface tension stress layer inside the glass. Compared with the substrate glass before strengthening, the occurrence of ion exchange will cause a change in the composition of the surface compression stress layer. Since the ion exchange depth is usually less than or equal to the thickness of the surface compression stress layer, the composition of the surface tension stress layer inside the glass will not change, that is, the composition of the surface tension stress layer is the same as that of the substrate glass before strengthening.

[0055] In some embodiments of the present application, the content of SiO2 can be 60.00 mol%, 61.00 mol%, 62.00 mol%, 63.00 mol%, 64.00 mol%, 65.00 mol%, 66.00 mol%, 67.00 mol%, 68.00 mol%, 69.00 mol%, 70.00 mol%, 71.00 mol%, 72.00 mol%, 73.00 mol%, 74.00 mol%, 75.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; it should be understood that in the embodiments, any of the above ranges can be combined with any other range.

[0056] In some embodiments of the present application, the content of Al2O3 can be 8.00 mol%, 9.00 mol%, 10.00 mol%, 11.00 mol%, 12.00 mol%, 13.00 mol%, 14.00 mol%, 15.00 mol%, 16.00 mol%, 17.00 mol%, 18.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; it should be understood that in the embodiments, any of the above ranges can be combined with any other range.

[0057] In some embodiments of the present application, the content of Li2O can be 7.00 mol%, 7.50 mol%, 8.00 mol%, 8.50 mol%, 9.00 mol%, 9.50 mol%, 10.00 mol%, 10.50 mol%, 11.00 mol%, 11.50 mol%, 12.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; it should be understood that in the embodiments, any of the above ranges can be combined with any other range.

[0058] In some embodiments of the present application, the content of Y2O3 can be 0 mol%, 1.00 mol%, 2.00 mol%, 3.00 mol%, 4.00 mol%, 5.00 mol%, 6.00 mol%, 7.00 mol%, 8.00 mol%, 9.00 mol%, 10.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; it should be understood that in the embodiments, any of the above ranges can be combined with any other range.

[0059] In some embodiments of the present application, the content of Na2O can be 2.00 mol%, 3.00 mol%, 4.00 mol%, 5.00 mol%, 6.00 mol%, 7.00 mol%, 8.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; it should be understood that in the embodiments, any of the above ranges can be combined with any other range.

[0060] In some embodiments of the present application, the content of MgO can be 0 mol%, 1.00 mol%, 2.00 mol%, 3.00 mol%, 4.00 mol%, 5.00 mol%, 6.00 mol%, 7.00 mol%, 7.50 mol%, 8.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; it should be understood that in the embodiments, any of the above ranges can be combined with any other range.

[0061] In some preferred embodiments of the present application, the composition of the surface compression stress layer of the chemically strengthened glass, expressed in mole percentage of oxides, further comprises: B2O3 0 to 5.00 mol%, preferably B2O3 0 to 3.00 mol%. The addition of B2O3 is beneficial to reducing the melting temperature of the glass and increasing the exchange rate of sodium ions and lithium ions during the chemical strengthening process. However, if the content is too high, it will affect the intrinsic structure of the chemically strengthened glass. Therefore, the content of B2O3 is controlled within the above range. For example, the content of B2O3 is 0.00 mol%, 0.50 mol%, 1.00 mol%, 1.50 mol%, 2.00 mol%, 2.50 mol%, 3.00 mol% or a value within the numerical range formed by any two of the above values as endpoints.

[0062] Currently, the substrate glass corresponding to the production of strengthened glass can be prepared by, but not limited to, the following methods: overflow method, float method, and rolling method. Among them, the float process has the advantages of large production volume, large sheet size, and low cost compared to other methods. However, the inventors of the present application have found that the existing lithium aluminosilicate chemically strengthened glass that can achieve high stress levels and high mechanical properties is generally not suitable for mass production by the float process because the aluminum content in its substrate glass is too high, which will cause the melting temperature of the glass to increase, shorten the glass melting property, and further increase the decrease in viscosity of the glass melt between 800 °C and 1200 °C. At the same time, aluminum and lithium are one of the main components for precipitating spodumene crystals. Too high aluminum and / or lithium content will increase the crystallization upper limit temperature of the glass, and the glass will have crystallization defects or even devitrification during the float production process, so it cannot be produced by the float process. Therefore, for the substrate glass generally mass-produced by the float process, expressed in mole percentage of oxides, the content of both Al2O3 and Li2O does not exceed 12 mol%. However, reducing the content of Al2O3 is not conducive to increasing the stress effect generated by unit ion exchange, and reducing the content of Li2O is not conducive to increasing the exchange amount of sodium ions and lithium ions, and thus not conducive to increasing the deep compressive stress and Young's modulus. Due to the limitations of the float process, the content of Al2O3 and Li2O in the substrate glass suitable for mass production by the float process is limited, resulting in the maximum value of the surface compression stress line density CT_LD max and the maximum value of the surface compression stress CS max obtained by chemically strengthening the existing substrate glass mass-produced by the float process are lower than those of the substrate glass capable of preparing chemically strengthened glass with high stress levels and high mechanical properties. That is, the mechanical strength of the chemically strengthened glass prepared from the existing substrate glass produced by the float process is relatively low, and thus the mechanical strength of the products (such as mobile phone covers, aviation glass, automotive glass, etc.) made of this chemically strengthened glass is relatively low and cannot meet the actual requirements.

[0063] Based on the above problems, in this application, by optimizing the formulation, the substrate glass corresponding to the chemically strengthened glass that can meet the performance requirements of this application can also be mass-produced by the float process.

[0064] In some embodiments of the present application, the composition of the compressive stress layer of the chemically strengthened glass, expressed in mole percentage of oxides, comprises: 60.00 - 75.00 mol% of SiO2, 8.00 - 12.00 mol% of Al2O3, 7.00 - 12.00 mol% of Li2O, 1.00 - 3.00 mol% of Y2O3, 2.00 - 8.00 mol% of Na2O, 0 - 8.00 mol% of MgO, and 0.10 - 3.00 mol% of La2O3.For example, the content of SiO2 can be 60.00 mol%, 61.00 mol%, 62.00 mol%, 63.00 mol%, 64.00 mol%, 65.00 mol%, 66.00 mol%, 67.00 mol%, 68.00 mol%, 69.00 mol%, 70.00 mol%, 71.00 mol%, 72.00 mol%, 73.00 mol%, 74.00 mol%, 75.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; the content of Al2O3 can be 8.00 mol%, 8.50 mol%, 9.00 mol%, 9.50 mol%, 10.00 mol%, 10.50 mol%, 11.00 mol%, 11.50 mol%, 12.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; the content of Li2O can be 7.00 mol%, 7.50 mol%, 8.00 mol%, 8.50 mol%, 9.00 mol%, 9.50 mol%, 10.00 mol%, 10.50 mol%, 11.00 mol%, 11.50 mol%, 12.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; the content of Y2O3 can be 1.00 mol%, 1.25 mol%, 1.50 mol%, 1.75 mol%, 2.00 mol%, 2.25 mol%, 2.50 mol%, 2.75 mol%, 3.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; the content of Na2O can be 2.00 mol%, 3.00 mol%, 4.00 mol%, 5.00 mol%, 6.00 mol%, 7.00 mol%, 8.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; the content of MgO can be 0 mol%, 1.00 mol%, 2.00 mol%, 3.00 mol%, 4.00 mol%, 5.00 mol%, 6.00 mol%, 7.00 mol%, 8.00 mol% or a value within the numerical range formed by any two of the above values as endpoints; the content of La2O3 can be 0.10 mol%, 0.20 mol%, 0.50 mol%, 0.75 mol%, 1.00 mol%, 1.25 mol%, 1.50 mol%, 1.75 mol%, 2.00 mol%, 2.25 mol%, 2.50 mol%, 2.75 mol%, 3.00 mol% or a value within the numerical range formed by any two of the above values as endpoints.

[0065] SiO2 and Al2O3 are the main components that make up the glass network structure. The addition of both is beneficial to improving the intrinsic strength of the glass. SiO2 can also improve the acid resistance of the glass and reduce glass scratches; Al2O3 can also enhance the stress effect generated by ion exchange. However, excessive Al2O3 will increase the melting difficulty and at the same time increase the crystallization upper limit temperature, and excessive SiO2 will also increase the melting difficulty.

[0066] Y2O3 can cause changes in the glass network structure inside the glass. The formed Si-O-Y bonds reconnect the isolated island-like network structure in the glass, which can improve the glass structure, increase the glass network stability, and then enhance the unit stress generated by sodium-lithium exchange and improve the stress effect brought by ion exchange. And because the relative atomic mass of Y is relatively large and the radius is also relatively large, there is a high field strength in the glass network, which will aggregate the free alkali metals and alkaline earth metals inside and has a tightening trend on the network structure. As a result, the overall structure of the glass is arranged compactly with a high degree of densification, and the atomic packing density of the glass can be improved. Therefore, the presence of Y2O3 can also reduce the structural relaxation degree of the glass after annealing, and at the same time improve the Vickers hardness of the glass and enhance the scratch resistance. However, too much Y2O3 will lead to an increase in the crystallization upper limit of the glass and will also affect the ion exchange due to the overly dense structure of the glass, which will affect the ion exchange rate and ion exchange depth.

[0067] Alkali metals are the main components participating in ion exchange. Na ions are the key exchange ions for forming surface high compressive stress, and Li ions are the key exchange ions for forming deep compressive stress. However, since alkali metal oxides are in a free state inside the glass, their excess oxygen ions will break the bridging oxygen, damage the glass network structure, and reduce the intrinsic strength of the glass. And because Li2O is the main component of lithium aluminosilicate crystallization, too much of it will increase the crystallization upper limit of the glass and cause production difficulties. The increase in Na2O can increase CS, reduce the crystallization tendency of lithium aluminosilicate glass, and lower the crystallization upper limit temperature, but too much will hinder sodium-lithium exchange, thereby reducing the deep stress and affecting the anti-drop performance of the glass. The increase in K2O can lower the crystallization upper limit temperature, but excessive K ions will hinder the ion exchange rate, especially the potassium-sodium ion exchange. Therefore, the content of each alkali metal oxide in the scheme needs to be strictly controlled.

[0068] Magnesium oxide (MgO) exists as a network intermediate. It has the function of reducing the high-temperature viscosity of the glass and can also increase the Young's modulus of the glass. Due to the small radius of magnesium ions, their filling density in the glass network structure is large, and the effect on enhancing the Young's modulus is relatively large. Also because of the small radius of magnesium ions, it has the least hindrance to ion exchange among alkaline earth metal oxides. However, excessive magnesium oxide (MgO) will still hinder the progress of ion exchange.

[0069] The addition of La2O3 can reduce the crystallization tendency of the lithium aluminosilicate glass formula containing only Y2O3 to obtain a lower upper crystallization temperature. Moreover, La2O3 can further increase the denseness and intrinsic strength of the glass. However, when there is too much La2O3, it will affect the stress effect generated by the unit exchange amount.

[0070] By optimizing the formula, the crystallization temperature of the substrate glass corresponding to the chemically strengthened glass of this application is less than or equal to 1200 °C, and the glass melt has an appropriate viscosity during the preparation process, so that it can be prepared by the float process. Moreover, this substrate glass has a high ion exchange stress effect. During the process of chemically strengthening to prepare the chemically strengthened glass, a high stress effect can be achieved with a low sodium-lithium exchange amount, and the prepared chemically strengthened glass has excellent mechanical strength. At the same time, due to the high ion exchange stress effect of this substrate glass, when chemically strengthening using a salt bath, the content of lithium ions released by the glass into the salt bath is less than that of the existing lithium aluminosilicate glass, which is beneficial to improving the service life of the salt bath. Moreover, the reduction of the ion exchange amount is beneficial to reducing the discreteness of the anti-drop height distribution of batch samples and ensuring the stable strength performance of the mass-produced chemically strengthened glass. The above-mentioned chemical strengthening treatment process is also the process of ion exchange of the substrate glass in the salt bath. It can be understood that the substrate glass corresponding to the strengthened glass of this application can also adopt the above-mentioned other preparation methods known in the art.

[0071] In some embodiments of this application, expressed in terms of the molar percentage of oxides, the composition in the tensile stress layer of the chemically strengthened glass satisfies that La2O3 / Y2O3 is 0.2 - 1.0. Y2O3 is beneficial to improving the stress effect generated during the ion exchange of the substrate glass. The addition of La2O3 can reduce the crystallization tendency of the lithium aluminosilicate glass formula containing only Y2O3 to obtain a lower upper crystallization temperature. Moreover, La2O3 can further increase the denseness and intrinsic strength of the glass. However, when there is too much La2O3, it will affect the stress effect generated by the unit exchange amount. By controlling the ratio of La2O3 / Y2O3 within the above range, for example, La2O3 / Y2O3 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 or a value within the numerical range formed by any two of the above values as endpoints, it is possible to reduce the upper crystallization temperature of the substrate glass while ensuring that the Young's modulus and stress effect of the substrate glass meet the requirements, which is beneficial for float production and for obtaining a substrate glass with a high Young's modulus.

[0072] In some preferred embodiments of the present application, in terms of the molar percentage of oxides, the composition in the compressive stress layer of the chemically strengthened glass satisfies: Al2O3 + Li2O ≤ 22.00 mol%, preferably, Al2O3 + Li2O ≤ 20.00 mol%. Al2O3 and Li2O are the main components for precipitating spodumene crystals. By controlling the contents of Al2O3 and Li2O within the above ranges, for example, Al2O3 + Li2O can be 16.00 mol%, 17.00 mol%, 18.00 mol%, 19.00 mol%, 20.00 mol%, 21.00 mol%, 22.00 mol% or a value within the numerical range formed by any two of the above values as endpoints, the crystallization phenomenon occurring during the preparation process can be effectively improved, the mechanical strength of the chemically strengthened glass can be prevented from being affected, and at the same time, the glass melt can be ensured to have a long glass melting property, so that it can be better applied to the float process.

[0073] In some preferred embodiments of the present application, in terms of the molar percentage of oxides, the composition in the compressive stress layer of the chemically strengthened glass satisfies: La2O3 / Y2O3 is 0.2 - 1.0, Al2O3 + Li2O ≤ 22.00 mol%, preferably, Al2O3 + Li2O ≤ 20.00 mol%. The substrate glass corresponding to the chemically strengthened glass can be prepared by the float process, and the obtained substrate glass has good mechanical strength, and the chemically strengthened glass has good drop resistance.

[0074] In some embodiments of the present application, in terms of the molar percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass further contains: SrO 0 - 3.00 mol%. The addition of SrO is beneficial to reducing the crystallization rate during crystallization and further preventing the occurrence of the crystallization phenomenon. By controlling the content of SrO within the above ranges, for example, the content of SrO can be 0.00 mol%, 0.50 mol%, 1.00 mol%, 1.50%, 2.00 mol%, 2.50 mol%, 3.00 mol% or a value within the numerical range formed by any two of the above values as endpoints, which is beneficial to further preventing the occurrence of the crystallization phenomenon.

[0075] In some embodiments of the present application, expressed in mole percentage of oxides, the contents of MgO and SrO satisfy SrO / (MgO + SrO) ≤ 0.35, preferably 0.05 ≤ SrO / (MgO + SrO) ≤ 0.35. By controlling the value of SrO / (MgO + SrO) within the above range, for example, the value of SrO / (MgO + SrO) can be 0.05, 0.09, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.30, 0.35 or a value within the numerical range formed by any two of the above numerical values as endpoints, it is beneficial to ensure the ion exchange rate during the chemical strengthening process of the substrate glass and avoid too long strengthening time.

[0076] In some embodiments of the present application, expressed in mole percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass further comprises: K2O 0 - 3.00 mol%, preferably, K2O 1.00 - 3.00 mol%, more preferably, K2O 1.00 - 2.00 mol%. The addition of K2O is beneficial to reducing the upper limit temperature of crystallization, but too high a content will affect the ion exchange stress effect. By controlling the content of K2O within the above range, for example, the content of K2O can be 0.00 mol%, 0.50 mol%, 1.00 mol%, 1.50 mol%, 2.00 mol%, 2.50 mol%, 3.00 mol% or a value within the numerical range formed by any two of the above numerical values as endpoints, it is beneficial to reduce the upper limit temperature of crystallization and at the same time ensure that the ion exchange stress effect meets the requirements.

[0077] In some embodiments of the present application, expressed in mole percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass further comprises: SrO 0 - 3.00 mol%, K2O 0 - 3.00 mol%. It is possible to prepare the substrate glass corresponding to the chemically strengthened glass by the float process, and the obtained substrate glass has good mechanical strength, and the chemically strengthened glass has good anti-drop performance.

[0078] In some embodiments of the present application, expressed in mole percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass satisfies: SiO2 64.00 - 70.00 mol%, and / or Li2O 8.00 - 12.00 mol%, and / or Na2O 4.00 - 6.00 mol%, and / or MgO 2.00 - 7.50 mol%, and / or La2O3 0.20 - 1.50 mol%. That is, the composition of the compressive stress layer of the chemically strengthened glass satisfies at least one of SiO2 64.00 - 70.00 mol%, Li2O 8.00 - 12.00 mol%, Na2O 4.00 - 6.00 mol%, MgO 2.00 - 7.50 mol%, La2O3 0.20 - 1.50 mol%. By further optimizing the glass formula, not only can the requirements of float production be better met, the occurrence of crystallization be effectively avoided, and the service life of the salt bath be improved, but also it is beneficial to obtain chemically strengthened glass with higher mechanical strength.

[0079] In some embodiments of the present application, expressed in mole percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass comprises: SiO2 60.00 - 75.00 mol%, Al2O3 8.00 - 12.00 mol%, Li2O 7.00 - 12.00 mol%, Y2O3 1.00 - 3.00 mol%, Na2O 2.00 - 8.00 mol%, MgO 1.00 - 8.00 mol%, La2O3 0.20 - 3.00 mol%, and La2O3 / Y2O3 is 0.2 - 1.0.

[0080] In some embodiments of the present application, expressed in mole percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass comprises: SiO2 64.00 - 70.00 mol%, Al2O3 8.00 - 12.00 mol%, Li2O 8.00 - 12.00 mol%, Y2O3 1.00 - 3.00 mol%, Na2O 4.00 - 6.00 mol%, MgO 2.00 - 7.50 mol%, La2O3 0.20 - 1.50 mol%.

[0081] In some preferred embodiments of the present application, expressed in mole percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass satisfies: La2O3 / Y2O3 is 0.2 - 1.0, and Al2O3 + Li2O ≤ 22.00 mol%. The base glass corresponding to the chemically strengthened glass can be prepared by the float process, and the obtained base glass has good mechanical strength, and the chemically strengthened glass has good anti-drop performance.

[0082] In some embodiments of the present application, for the chemically strengthened glass with a thickness of 0.7 mm, the anti-drop test is carried out using 120-mesh sandpaper, and the average anti-sandpaper drop height is greater than or equal to 1.60 m, preferably greater than or equal to 1.70 m. For example, the average anti-sandpaper drop height can be 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 or a value within the numerical range formed by any two of the above values as endpoints, indicating that the chemically strengthened glass provided by the present application has excellent anti-drop performance.

[0083] In some embodiments of the present application, for the 0.7-mm thick chemically strengthened glass, the anti-drop test is carried out using 120-mesh sandpaper, and the B10 value of the anti-sandpaper drop height is greater than or equal to 1.1 m, preferably 1.1 - 2.0 m. For example, the B10 value of the anti-sandpaper drop height can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0 or a value within the numerical range formed by any two of the above values as endpoints, indicating that the chemically strengthened glass provided by the present application has excellent anti-drop performance.

[0084] In some embodiments of the present application, the decrease rate of the B10 value of the anti-sandpaper drop height of the 0.7-mm thick chemically strengthened glass compared to the average anti-sandpaper drop height does not exceed 25%, and the sandpaper mesh number used in the test is 120 mesh. Among them, B10 means that when the chemically strengthened glass of the same batch drops at this height, it is expected that 10% of the chemically strengthened glass will fail or malfunction, and it can be used to evaluate the discreteness of the anti-drop height distribution of the chemically strengthened glass. For example, the decrease rate Y of the B10 value of the anti-sandpaper drop height of the 0.7-mm thick chemically strengthened glass compared to the average anti-sandpaper drop height H0 can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25% or a value within the numerical range formed by any two of the above values as endpoints, thereby indicating that the discreteness of the anti-drop height distribution of the chemically strengthened glass provided by the present application is small, ensuring that the mass-produced chemically strengthened glass has relatively stable anti-drop performance. Among them, Y = (H0 - B10) / H0 × 100%.

[0085] The second aspect of the present application provides a glass device, which is made of the chemically strengthened glass in any of the above embodiments. For example, the glass device can include but is not limited to a mobile phone display protection cover plate, a mobile phone battery back cover plate, a notebook screen protection cover plate, an automotive central control glass cover plate, etc. The chemically strengthened glass provided by the present application has good anti-drop performance, so the glass device provided by the present application also has good anti-drop performance.

[0086] The third aspect of the present application provides an electronic device, which includes the chemically strengthened glass in any of the above embodiments. For example, the electronic device includes a mobile phone, a tablet computer, or other electronic terminals, and other electronic terminals may include, but are not limited to, smart wearables (such as smart watches, smart bracelets, smart glasses, etc.), displays (such as high-definition displays, in-vehicle displays, on-board displays, etc.), televisions, etc. Exemplarily, the electronic device may include a housing and electronic components partially located within the housing. The housing includes a front surface, a rear surface, and side surfaces. The electronic components include a display device, and the display device is located at or adjacent to the front surface of the housing. The chemically strengthened glass provided by the present application can be applied to the front surface and / or the rear surface and / or the side surfaces of the housing; preferably, the electronic device may further include a covering article covering the front surface of the housing or located on the display device, and the chemically strengthened glass provided by the present application can be applied to the covering article.

[0087] Test method:

[0088] 1. Test of the tensile stress line density CT_LD

[0089] Calculated from the stress parameters measured by the SLP-2000 stress meter, the tensile stress line density CT_LD is the ratio of the sum of the tensile stresses of the chemically strengthened glass measured by the SLP-2000 stress meter to the glass thickness.

[0090] 2. Calculation of S

[0091] The following takes Example 3 as an illustration, and the rest of the examples are calculated in the same way.

[0092] The cross-section of the chemically strengthened glass in Example 3 was scanned by a Bruker EDS-X-ray energy spectrometer with a magnification of 250 times, a ray intensity HV of 10.0 KeV, and a scanning range of 300 μm. As Figure 1 shown, in order to reduce deviation and accurately measure the surface position of the chemically strengthened glass, the starting test position is a dozen or so micrometers on the surface of the chemically strengthened glass. Figure 1 The direction indicated by the arrow in the figure is the test scanning direction, and the distance from the starting scanning position to the surface of the chemically strengthened glass is 14.4 μm. In this way, in the 0-300 μm test diagram, there will be a trend of increasing intensity from low to high and then slowly decreasing. When processing the data, the invalid data from low to high in the front is excluded, and the signal intensity distribution curve corresponding to the sodium element content as shown in Figure 2 is obtained. Then, the allometric function in professional data plotting software (such as SciDAVis, etc.) is used for fitting to obtain as shown in Figure 3The smooth curve shown. As can be seen from the figure, as the depth increases, the signal intensity corresponding to the sodium element content gradually decreases, and the decreasing speed gradually slows down, and finally approaches the signal intensity corresponding to the sodium element content in the tensile stress layer, and the signal intensity corresponding to this content is y0 in Figure 3 and is y0 = 94.8 in Figure 3 ; in addition, Figure 3 in Figure 3 , x1 to x2 is the thickness range corresponding to the compressive stress layer, x1 is the test depth corresponding to the surface of the chemically strengthened glass, and x2 is the test depth value corresponding to the zero compressive stress. In Figure 3 x1 = 14.4 and x2 = 149.4. Figure 3 In Figure 3 , the area of the figure enclosed by x = x1, x = x2, y = y0 and the smooth curve is S, and the area of this figure can be calculated by professional data plotting software (such as SciDAVis, etc.).

[0093] 3. Testing of stress parameters

[0094] Testing conditions for surface CS and the stress exchange depth of potassium and sodium: Use the stress meter FSM-6000 of Orihara in Japan for testing, and the light source wavelength is 596 nm. Before starting the test, first fill in the thickness, refractive index, and photoelastic coefficient of the sample to be tested in the parameter table, and then conduct the test to obtain the stress parameter values of the sample to be tested.

[0095] Testing conditions for DOL_0 and CT_LD: Use the stress meter SLP-2000 of Orihara in Japan for testing, and the light source wavelength is 518 nm. Before starting the test, first fill in the thickness, refractive index, and photoelastic coefficient of the sample to be tested in the parameter table, adjust the exposure time to 5000 usec, and then conduct the test to obtain the stress parameter values of the sample to be tested.

[0096] For glasses with different compositions, their refractive indices and photoelastic coefficients are different. In the present invention, the refractive index is tested by an Abbe refractometer, and the photoelastic coefficient is tested by a UNIPT ABR-10A dual-frequency laser stress meter.

[0097] When using a stress meter to test the stress parameters of a chemically strengthened glass sample, it is necessary to first drop its special refractive liquid on the corresponding stress meter, then wipe the chemically strengthened glass product clean, place it on the test path, and perform instrument settings according to the above test conditions, and then conduct the test to obtain the stress parameter values of the chemically strengthened glass. Among them, the refractive index of the refractive liquid used for SLP-2000 is 1.51, and the refractive index of the refractive liquid used for FSM-6000 is 1.72.

[0098] 4. Testing of Young's modulus

[0099] Place the substrate glass (25 mm × 85 mm × 2.5 mm) prepared during the preparation of each example on a testing instrument (manufacturer: Kegonas Instrument Trading Co., Ltd., model MK7), then vibrate it with the tip, obtain the ultrasonic vibration propagation result through the receiver placed on the upper end, and then obtain the Young's modulus through the instrument. The Young's moduli of the substrate glasses corresponding to Formulas 1 to 9 in Table 1 are 84 GPa, 88 GPa, 89 GPa, 91 GPa, 90 GPa, 89 GPa, 89 GPa, 90 GPa, and 89 GPa in sequence. After the substrate glass is strengthened, its Young's modulus will further increase, so that the Young's moduli of the chemically strengthened glasses obtained are all greater than or equal to 85 GPa.

[0100] 5. Measurement of the amount of lithium ions released in the salt bath

[0101] Measure the mass of the substrate glass (length × width × thickness: 50 mm × 50 mm × 0.7 mm) using a Shimadzu precision balance, denoted as m1. The precision of the balance is one ten-thousandth of a gram, and the balance model is AUW120D.

[0102] Take out the substrate glass after ion exchange in a 100 wt% NaNO3 salt bath at 450 °C for t hours, clean it with deionized water, and then measure its mass as m2. Here, t hours is the treatment time to obtain the maximum value of the compressive stress line density CT_LD max The treatment time can be obtained according to the measurement of the above-mentioned maximum value of the compressive stress line density CT_LD max

[0103] The mass increment Δw of the substrate glass before and after ion exchange is the mass increment brought by the exchange of sodium ions for lithium ions, Δw = m2 - m1, with the unit of mg. In addition, sodium ions and lithium ions are exchanged in an equimolar manner, so Δw = M Na × n - M Li × n, so n = Δw / (M Na - M Li ), and the amount of lithium ions released in the salt bath = M Li × n. Among them, M Na is the relative atomic mass of sodium, 23, M Li is the relative atomic mass of lithium, 7, and n is the number of moles of sodium ions or lithium ions exchanged. After calculation, it can be known that when obtaining the maximum value of the compressive stress line density CT_LD max , the amount of lithium ions released from the 0.7 mm thick substrate glass into the salt bath = M Li × Δw / (M Na - M Li ).

[0104] 6. Measurement of the upper crystallization temperature

[0105] Break the substrate glass into small pieces with a size of 2 mm to 5 mm, and then put them into a long quartz groove and spread them out.

[0106] Set the temperature range of the gradient furnace with the model number JKZC-XJY01, such as a temperature range of 1050 °C to 1225 °C, and take at least 6 temperature points from high to low for each temperature range.

[0107] After the gradient furnace reaches the preset temperature range, put the long quartz groove with the sample into the gradient furnace, so that the 6 temperature points respectively correspond to the glass samples at 6 positions in the long quartz groove. Refer to Figure 4 After keeping the long quartz groove in the gradient furnace at a constant temperature for 60 - 70 min, take out the long quartz groove.

[0108] Observe the glass samples at different positions in the long quartz groove. If the glass samples become devitrified or foggy, it is determined that the glass samples at that place have crystallized. If the glass samples are completely transparent, it is determined that the glass samples at that place have not crystallized. Refer to Figure 5 , Figure 5 In the long quartz groove of, the upper region is a completely transparent sample, the lower region is a devitrified sample, and there are partially foggy samples between the completely transparent sample and the devitrified sample. When observing, tools such as magnifying glasses and microscopes can be used.

[0109] Determination of the upper crystallization temperature: The upper crystallization temperature range is between the temperature point corresponding to the completely transparent sample and the temperature point corresponding to the adjacent devitrified or foggy sample, and the average value of the two temperature points is taken as the upper crystallization temperature.

[0110] If all the glass samples in the long quartz groove crystallize within the temperature range set by the gradient furnace, reset the upper limit temperature of the temperature range of the gradient furnace and measure the upper crystallization temperature of the glass samples. If all the glass samples in the long quartz groove do not crystallize within the temperature range set by the gradient furnace, reset the lower limit temperature of the temperature range of the gradient furnace and measure the upper crystallization temperature of the glass samples.

[0111] 7. Anti-drop height test and calculation of B10

[0112] Average anti-sandpaper drop height: The value obtained by dividing the sum of the anti-sandpaper drop heights measured for multiple glass samples by the number of samples measured, which is used to characterize the anti-cracking performance of the glass on the contact surface.

[0113] Take at least 10 samples for each batch for testing, average anti-sandpaper drop height

[0114]

[0115] Among them, n is the number of glass sample pieces tested for each batch, and hi is the anti-sandpaper drop height measured for a single sample piece.

[0116] Among them, the test method for the anti-sandpaper drop height of the sample is as follows:

[0117] Step 1: Stick the glass sample to be tested with a length, width and thickness of 158.8 mm × 72.8 mm × 0.7 mm on the front of a 200 g model machine;

[0118] Step 2: Place the model machine on a Green Map LT-SKDL-CD type drop tester, make the glass sample face the sandpaper, and drop it with a certain drop height, impacting the 120-mesh sandpaper directly below the model machine to simulate the normal mobile phone drop posture.

[0119] If the glass sample does not break, the drop height of the model machine is increased regularly. For example, starting from a drop height of 0.4 m, the sample is dropped and impacted once. If it does not break, the height is increased by 0.1 m each time and dropped again until the glass sample breaks.

[0120] Step 3: Record the previous drop height when the glass sample breaks as the anti-sandpaper drop height. For example, if the drop height at the time of breakage is 0.5 m, the anti-sandpaper drop height of the sample is 0.4 m.

[0121] B10 of the anti-sandpaper drop height: This is a statistical value calculated by the Weibull distribution, which is a statistical analysis of the anti-sandpaper drop height data obtained from testing multiple samples, and the discreteness of the anti-sandpaper drop height distribution of the samples is considered during the calculation. The specific meaning of B10 in this application refers to the anti-sandpaper drop height corresponding to the chemically strengthened glass samples with a failure ratio of 10%, which can be used to evaluate the anti-drop ability of a certain type of chemically strengthened glass.

[0122] Calculation of B10 of the anti-sandpaper drop height:

[0123] Take the anti-sandpaper drop heights measured from m chemically strengthened glass samples, and record them as N1 to Nm in sequence. Then set the parameter K value of the PERCENTILE function to 0.1, and the result obtained by calculating the data of N1 to Nm through this function is recorded as the B10 value of the anti-sandpaper drop height.

[0124] Example 1

[0125] According to the formulation 1 in Table 1, the glass production raw material formulation is designed and converted for batching, with a total mass of 1600 g. And 0.4 wt% (based on the total mass of formulation 1) of the clarifying agent sodium chloride is added. It is placed in a platinum crucible and heated to 1650 °C in a high-temperature melting furnace for 10 h to melt, and then poured into a forming mold to cool and form. After cooling to 800 °C, it is placed in an annealing furnace and annealed at 560 °C for 2000 min, and then cooled to 500 °C in 300 min and held at 500 °C for 300 min. Then, it is cooled down to 400 °C, 300 °C, and 200 °C successively according to this cooling method to achieve gradient slow cooling, and then cooled to room temperature with the furnace to obtain glass sample bricks.

[0126] Then, the glass sample bricks are subjected to multi-wire cutting, CNC machining on a numerically controlled lathe, thinning, and polishing to obtain substrate glass, and the thickness of the substrate glass is 0.7 mm.

[0127] Then, the substrate glass is first treated in a 100 wt% NaNO3 salt bath at 420 °C for 3 h, and then treated in a 100 wt% KNO3 salt bath at 420 °C for 1 h to obtain chemically strengthened glass, and the thickness t of the chemically strengthened glass is 0.7 mm.

[0128] Examples 2 to 9

[0129] Except that formulation 1 is sequentially replaced with formulations 2 to 9 in Table 1, the rest is the same as in Example 1.

[0130] Comparative Examples 1 to 6

[0131] Except that the strengthening process and formulation are adjusted according to Table 2, the rest is the same as in Example 1.

[0132] The parameters of each example and comparative example are shown in Table 2 in detail, and the performance test results are shown in Table 3 in detail.

[0133] Table 1

[0134]

[0135] Note: The content of each substance in Table 1 is in mole percentage, and " / " means that the corresponding substance does not exist.

[0136] Table 2

[0137]

[0138] Note: " / " in Table 2 indicates that there is no corresponding parameter. Taking Example 1 as an example, "420°C * 100wt% NaNO3 * 3h 420°C * 100wt% KNO3 * 1h" in Table 2 means that the substrate glass is first treated in a 100wt% NaNO3 salt bath at 420°C for 3h, and then treated in a 100wt% KNO3 salt bath at 420°C for 1h to obtain chemically strengthened glass. The other examples and comparative examples are understood analogously in turn.

[0139] Table 3

[0140]

[0141] Referring to Table 3, it can be seen from Examples 1 to 9 and Comparative Examples 1 to 4 that the chemically strengthened glass of the present application has a higher average anti-sanding paper drop height, B10 value of the anti-sanding paper drop height, and a lower reduction Y compared with the comparative examples. Therefore, the chemically strengthened glass provided by the present application has excellent anti-drop performance and a small discreteness in the distribution of the anti-drop height. It can be seen from Examples 1 to 9, Comparative Example 5 and Comparative Example 6 that Comparative Example 5 and Comparative Example 6 have undergone over-strengthening treatment. Although they have a relatively high average anti-sanding paper drop height, the reduction Y is significantly higher than that of the examples of the present application, indicating that the discreteness of the anti-drop height distribution of the samples in the same batch is large, and further resulting in extremely unstable anti-drop performance of the mass-produced chemically strengthened glass. In addition, it can also be seen from Table 3 that the surface CS and the depth DOL_0 of the compressive stress layer of the examples are equivalent to or better than those of the comparative examples, indicating that the chemically strengthened glass of the present application can achieve the mechanical strength in the prior art or further increase the mechanical strength. More importantly, the discreteness of the anti-drop height distribution of the chemically strengthened glass in the examples is small, which can ensure that the mass-produced chemically strengthened glass has relatively stable anti-drop performance.

[0142] The upper crystallization temperature of the substrate glass corresponding to the chemically strengthened glass of Examples 3 to 6, Example 8 and Example 9 is less than 1200°C, and it can be produced by the float process. The obtained chemically strengthened glass has excellent anti-drop performance, and at the same time, the amount of lithium ions released in the salt bath is relatively low, which is beneficial to improving the service life of the salt bath and further reducing the production cost of mass production. Although the upper crystallization temperature of the substrate glass corresponding to the chemically strengthened glass of Comparative Examples 1 to 3 and Comparative Example 6 is also less than 1200°C, their reduction Y is higher than that of the examples. That is, although these comparative examples can also be produced by the float process, the anti-drop performance and the discreteness of the anti-drop height distribution of the chemically strengthened glass obtained in the present application are significantly better than these comparative examples.

[0143] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0144] Each embodiment in this specification is described in a related manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments.

[0145] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are all included in the protection scope of the present application.

Claims

1. A chemically strengthened glass, wherein, The chemically strengthened glass satisfies the following conditions: The compressive stress line density CT_LD of the chemically strengthened glass is greater than or equal to 44500 MPa / mm and less than or equal to 70000 MPa / mm, and the ratio of CT_LD / S is greater than or equal to 7.5 and less than or equal to 20; The surface CS of the chemically strengthened glass is greater than or equal to 1000 MPa and less than or equal to 1200 MPa; The chemically strengthened glass includes a compressive stress layer on the surface of the chemically strengthened glass and a tensile stress layer inside the chemically strengthened glass. By using an X-ray energy spectrometer to test the signal intensity distribution curve of the sodium element content along the thickness direction of the chemically strengthened glass, fitting the signal intensity distribution curve into a smooth curve, the area of the figure enclosed by x = x1, x = x2, y = y0 and the smooth curve is S, x1 is the test depth value corresponding to the surface of the chemically strengthened glass, x2 is the test depth value corresponding to the position where the compressive stress is zero, and y0 is the intensity value corresponding to the sodium element content in the tensile stress layer in the smooth curve; Wherein, expressed in terms of the molar percentage of oxides, the composition of the tensile stress layer of the chemically strengthened glass contains: SiO2 63.00 - 70.00 mol%, Al2O3 8.00 - 9.00 mol%, Li2O 8.00 - 12.00 mol%, Y2O3 1.00 - 2.50 mol%, Na2O 4.00 - 6.00 mol%, MgO 2.50 - 4.00 mol%, La2O3 0.50 - 2.00 mol%, K2O 0 - 0.50 mol%, SrO 0 - 2.00 mol%, ZrO2 0 mol%; and Wherein, expressed in terms of the molar percentage of oxides, the composition in the tensile stress layer of the chemically strengthened glass satisfies: La2O3 / Y2O3 is 0.2 - 1.

0.

2. The chemically strengthened glass according to claim 1, wherein, The surface CS of the chemically strengthened glass is greater than or equal to 1100 MPa and less than or equal to 1200 MPa.

3. The chemically strengthened glass according to claim 1, wherein, Expressed in terms of the molar percentage of oxides, in the composition of the tensile stress layer of the chemically strengthened glass: The content of SiO2 is 63.00 - 68.00 mol%; and / or, The content of Y2O3 is 1.50 - 2.00 mol%.

4. The chemically strengthened glass according to claim 1, wherein, Expressed in terms of the molar percentage of oxides, in the composition of the tensile stress layer of the chemically strengthened glass: The content of SiO2 is 63.00 - 65.50 mol%; and / or, The content of Na2O is 5.00 - 6.00 mol%; and / or, The content of La2O3 is 1.00 - 2.00 mol%; and / or, The content of Li2O is 8.00 - 10.00 mol%.

5. The chemically strengthened glass according to claim 1, wherein, Expressed in terms of the molar percentage of oxides, in the composition of the tensile stress layer of the chemically strengthened glass: The content of SiO2 is 63.00 mol%, 64.00 mol%, 65.00 mol%, 65.50 mol%, 66.00 mol%, 67.00 mol%, 68.00 mol%, 69.00 mol% or 70.00 mol%; and / or, The content of Al2O3 is 8.00 mol% or 9.00 mol%; and / or, The content of Li2O is 8.00 mol%, 8.50 mol%, 9.00 mol%, 9.50 mol%, 10.00 mol%, 10.50 mol%, 11.00 mol%, 11.50 mol% or 12.00 mol%; and / or, The content of Na2O is 4.00 mol%, 5.00 mol% or 6.00 mol%; and / or, The content of MgO is 3.00 mol% or 4.00 mol%; and / or, The content of Y2O3 is 1.50 mol%, 2.00 mol% or 2.50 mol%; The content of La2O3 is 0.50 mol%, 0.75 mol%, 1.00 mol%, 1.25 mol%, 1.50 mol%, 1.75 mol% or 2.00 mol%; and / or, La2O3 / Y2O3 is 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.67, 0.7, 0.8, 0.9 or 1.

0.

6. The chemically strengthened glass according to claim 1, wherein, The compressive stress line density CT_LD of the chemically strengthened glass is 44500 MPa / mm, 45000 MPa / mm, 46300 MPa / mm, 50000 MPa / mm, 55000 MPa / mm, 60000 MPa / mm, 65000 MPa / mm or 70000 MPa / mm; and / or, The ratio of CT_LD / S is 7.5, 8, 9, 9.8, 10, 11, 11.5, 12, 13, 14, 15, 16, 17, 18, 19 or 20; and / or, The surface CS of the chemically strengthened glass is 1000 MPa, 1050 MPa, 1100 MPa, 1136 MPa, 1138 MPa, 1147 MPa, 1150 MPa or 1200 MPa.

7. The chemically strengthened glass according to claim 1, wherein The depth DOL_0 of the compressive stress layer of the chemically strengthened glass is 0.15t to 0.22t, where t is the thickness of the strengthened glass.

8. The chemically strengthened glass according to claim 1, wherein The Young's modulus of the chemically strengthened glass is greater than or equal to 85 GPa.

9. The chemically strengthened glass according to claim 1, wherein, The Young's modulus of the chemically strengthened glass is greater than or equal to 90 GPa.

10. The chemically strengthened glass according to claim 9, wherein, The Young's modulus of the chemically strengthened glass is 90 GPa to 100 GPa.

11. The chemically strengthened glass according to claim 1, wherein, The compressive stress line density CT_LD of the chemically strengthened glass is greater than or equal to 44500 MPa / mm and less than or equal to 60000 MPa / mm.

12. The chemically strengthened glass according to claim 1, wherein, In terms of the molar percentage of oxides, the composition of the tensile stress layer of the chemically strengthened glass further contains: B2O3 0 to 5.00 mol%.

13. The chemically strengthened glass according to claim 1, wherein, In terms of the molar percentage of oxides, the composition of the tensile stress layer of the chemically strengthened glass further contains: B2O3 0 to 3.00 mol%.

14. The chemically strengthened glass according to claim 1, wherein, In terms of the molar percentage of oxides, the composition in the tensile stress layer of the chemically strengthened glass satisfies: Al2O3 + Li2O ≤ 20.00 mol%.

15. The chemically strengthened glass according to claim 1, wherein, Expressed in terms of mole percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass satisfies: SrO / (MgO + SrO) ≤ 0.

35.

16. The chemically strengthened glass according to claim 1, wherein, Expressed in terms of mole percentage of oxides, the composition of the compressive stress layer of the chemically strengthened glass satisfies: 0.05 ≤ SrO / (MgO + SrO) ≤ 0.

35.

17. The chemically strengthened glass according to any one of claims 1 to 16, wherein, For the 0.7 mm thick chemically strengthened glass, the anti-drop test is carried out using 120-mesh sandpaper, and the average anti-sandpaper drop height is greater than or equal to 1.60 m.

18. The chemically strengthened glass according to any one of claims 1 to 16, wherein, For the 0.7 mm thick chemically strengthened glass, the anti-drop test is carried out using 120-mesh sandpaper, and the average anti-sandpaper drop height is greater than or equal to 1.70 m.

19. The chemically strengthened glass according to any one of claims 1 to 16, wherein, For the 0.7 mm thick chemically strengthened glass, the anti-drop test is carried out using 120-mesh sandpaper, and the B10 value of the anti-sandpaper drop height is greater than or equal to 1.1 m.

20. The chemically strengthened glass according to any one of claims 1 to 16, wherein, For the 0.7 mm thick chemically strengthened glass, the decrease rate of the B10 value of the anti-sandpaper drop height compared to the average anti-sandpaper drop height does not exceed 25%, and the sandpaper mesh number used in the test is 120 mesh.

21. A glass device, wherein, The glass device is made of the chemically strengthened glass according to any one of claims 1 to 20.

22. An electronic device, which includes the chemically strengthened glass according to any one of claims 1 to 20.

23. The electronic device according to claim 22, wherein, The electronic device includes a mobile phone, a tablet computer, smart wearables, a display or a television.

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