Base material glass and chemically strengthened glass made from the base material glass

Abstract

This application provides a substrate glass and chemically strengthened glass made from the substrate glass, as well as glass devices and electronic devices containing the substrate glass or chemically strengthened glass. By optimizing the substrate glass formulation, the substrate glass not only meets the requirements of float glass mass production but also exhibits a high ion exchange stress benefit. When chemically strengthened glass is prepared using this substrate glass, a high stress benefit can be achieved at a low sodium-lithium exchange rate, resulting in high mechanical strength. Furthermore, due to the high ion exchange stress benefit of the substrate glass of this application, when chemically strengthened in a salt bath, the substrate glass releases less lithium ions into the salt bath than existing lithium aluminosilicate glass, which helps to extend the service life of the salt bath.

Description

Technical Field

[0001] The present application relates to the field of glass technology, and in particular to a substrate glass and a chemically strengthened glass made from the substrate glass. Background Art

[0002] In recent years, lithium-aluminum-silicon chemically strengthened glass has been widely used in mobile phone display covers and back covers. Existing cover glass capable of achieving high stress levels and excellent mechanical properties is typically reinforced with high aluminum and lithium content. Increasing the aluminum content improves the stress benefit per unit ion exchange, while increasing the lithium content increases the sodium-lithium ion exchange rate, thereby increasing deep compressive stress. Currently, the substrate glass for high-aluminum, high-lithium lithium-aluminum-silicon chemically strengthened glass is typically mass-produced using the overflow process.

[0003] Compared to the overflow process, the float glass process offers advantages such as high throughput, large sheet sizes, and low costs, and has gradually become the primary method for producing chemically strengthened lithium aluminum silicate glass. In float glass production, molten glass from the furnace flows through a runner into a tin bath. The lumpy glass is naturally flattened on the molten tin before being gradually flattened and shaped by stretchers on either side of the bath. Because the tin bath inlet temperature is typically 1200°C, the glass in the runner has a long residence time upon entering the bath. If the upper crystallization temperature exceeds 1200°C, the glass clumps will crystallize, becoming unable to spread out and even sticking to the channel opening. Therefore, if you want to produce flat glass using the float process, you must control the upper crystallization temperature to no more than 1200°C, and the lower the better. Furthermore, since the glass is flattened and shaped in the tin bath, the viscosity of the glass at 1200°C upon entering the bath is required to be low. Otherwise, it will be difficult to flatten naturally, making subsequent forming difficult. And during the molding period, that is, when the glass liquid is between 800℃ and 1200℃, the viscosity change needs to be small and the material properties need to be long, so that it is convenient for the edge drawing machine to perform molding operations. If the viscosity drops suddenly, it will increase the molding difficulty of the edge drawing machine.

[0004] Therefore, developing a substrate glass suitable for mass production using the float process and capable of achieving high ion exchange stress benefits, and using the substrate glass to prepare chemically strengthened glass with excellent mechanical strength has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The purpose of this application is to provide a substrate glass and chemically strengthened glass made from the substrate glass. This substrate glass not only meets the requirements of float glass mass production, thereby reducing glass manufacturing costs, but also, when used to prepare chemically strengthened glass with high stress levels and mechanical strength, the substrate glass exhibits a high ion exchange stress benefit, which can reduce the amount of lithium ions released into the salt bath, effectively extending the service life of the salt bath. The specific technical solution is as follows:

[0006] A first aspect of the present application provides a substrate glass, wherein, expressed in molar percentage of oxides, the composition of the substrate 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%, and La2O3 0.10-3.00 mol%.

[0007] In some embodiments of the present application, expressed as a molar percentage of oxides, La2O3 / Y2O3 is 0.2 to 1.0, preferably, La2O3 / Y2O3 is 0.2 to 0.8.

[0008] In some embodiments of the present application, expressed as a molar percentage of oxides, Al2O3+Li2O≤22.00 mol%, preferably, Al2O3+Li2O≤20.00 mol%.

[0009] In some embodiments of the present application, the composition of the substrate glass further comprises, expressed in molar percentage of oxides: SrO 0-3.00 mol %, preferably SrO 0-2.00 mol %, more preferably SrO 0.50-2.00 mol %.

[0010] In some embodiments of the present application, expressed as a mole percentage of oxides, SrO / (MgO+SrO)≤0.35.

[0011] In some embodiments of the present application, the composition of the substrate glass further comprises, expressed in molar percentage of oxides: K2O 0-3.00 mol%, preferably K2O 1.00-3.00 mol%, more preferably K2O 1.00-2.00 mol%.

[0012] In some embodiments of the present application, the composition of the substrate glass comprises, expressed in molar percentage of oxides: 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%.

[0013] In some embodiments of the present application, the composition of the substrate glass, expressed in molar percentage of oxides, includes: 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%, and La2O3 0.10-3.00 mol%.

[0014] In some embodiments of the present application, the composition of the substrate glass, expressed in molar percentage of oxides, includes: 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.

[0015] In some embodiments of the present application, the composition of the substrate glass, expressed in molar percentage of oxides, includes: 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%, and La2O3 0.20-1.50 mol%.

[0016] In some embodiments of the present application, the upper crystallization temperature of the substrate glass is less than or equal to 1185°C, preferably less than or equal to 1165°C.

[0017] In some embodiments of the present application, when ion exchange is performed on a 0.7 mm thick substrate glass in a 100 wt% NaNO3 salt bath at 450°C, the substrate glass is heated to 1 cm 2When 1 mg of sodium ions is introduced into the substrate glass by exchange, the stress benefit QF generated is greater than or equal to 90,000 MPa / mm, preferably greater than or equal to 95,000 MPa / mm and less than or equal to 200,000 MPa / mm.

[0018] In some embodiments of the present application, the maximum tensile stress linear density CT_LD obtained by ion exchange of 0.7 mm thick substrate glass in a 100 wt% NaNO3 salt bath at 450°C is max Greater than or equal to 50,000 MPa / mm, preferably 50,000 MPa / mm to 90,000 MPa / mm.

[0019] In some embodiments of the present application, the substrate glass obtains a maximum tensile stress linear density CT_LD in a 100 wt% NaNO3 salt bath at 450°C. max When the depth of the compressive stress layer DOL_0 formed on the substrate glass is 0.15t~0.22t, t is the thickness of the substrate glass.

[0020] In some embodiments of the present application, when a 0.7 mm thick substrate glass is placed in a 100 wt% NaNO3 salt bath at 450°C, the maximum tensile stress linear density CT_LD is obtained. max When the amount of lithium ions released from the substrate glass into the salt bath is less than or equal to 1.00 mg / cm 2 .

[0021] In some embodiments of the present application, when the ion exchange depth of 0.7 mm thick substrate glass is 4.9 to 5.1 μm in a 100 wt% KNO3 salt bath at 430°C, the CS obtained by the substrate glass is max Greater than or equal to 1000 MPa, preferably 1000 MPa to 1600 MPa.

[0022] In some embodiments of the present application, the Young's modulus of the substrate glass is greater than or equal to 85 GPa, preferably greater than or equal to 90 GPa and less than or equal to 100 GPa.

[0023] In some embodiments of the present application, the atomic packing density of the substrate glass is greater than or equal to 0.552 and less than or equal to 0.620.

[0024] In some embodiments of the present application, the bifurcation threshold of the substrate glass is greater than or equal to 40,000 MPa / mm, preferably 40,000 MPa / mm to 60,000 MPa / mm.

[0025] A second aspect of the present application provides a chemically strengthened glass, which is obtained by placing the substrate glass according to any of the above embodiments in a salt bath and subjecting it to ion exchange chemical strengthening. The chemically strengthened glass comprises a compressive stress layer and a tensile stress layer. The chemically strengthened glass has a compressive stress layer formed on the surface by chemically strengthened ion exchange and a tensile stress layer inside that is capable of achieving force balance with the compressive stress layer.

[0026] In some embodiments of the present application, the composition of the tensile stress layer is the same as that of the substrate glass in any of the above embodiments.

[0027] A third aspect of the present application provides a glass device, which is made of the substrate glass in any of the above embodiments or the chemically strengthened glass in any of the above embodiments.

[0028] A fourth aspect of the present application provides an electronic device comprising the chemically strengthened glass according to any one of the above embodiments.

[0029] In some embodiments of the present application, the electronic device includes a mobile phone, a tablet computer, a smart wearable device, a display, or a television. Among them, the smart wearable device includes a smart bracelet, a smart watch, and smart glasses, and the display includes a high-definition display, a car display, an aircraft display, etc.

[0030] Any of the above technical solutions has the following beneficial effects:

[0031] The present application provides a substrate glass suitable for mass production using the float process and capable of achieving high ion exchange stress benefits. This substrate glass meets the requirements for mass production using the float process and is beneficial for reducing the manufacturing cost of cover glass. When using this substrate glass to prepare chemically strengthened glass, a high stress benefit can be achieved at a relatively low sodium-lithium exchange rate, resulting in chemically strengthened glass with excellent mechanical strength. Furthermore, because the substrate glass of the present application has a high ion exchange stress benefit, when chemically strengthened using a salt bath, the amount of lithium ions released by the substrate glass into the salt bath is less than that of existing lithium aluminosilicate glass, which is beneficial for increasing the service life of the salt bath. Furthermore, the reduction in the ion exchange rate helps reduce the discreteness of the drop height distribution of batch samples, ensuring the stable strength performance of mass-produced chemically strengthened glass.

[0032] Of course, it is not necessary to achieve all the advantages described above at the same time when implementing any product or method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0034] Figure 1 is a schematic structural diagram of a stress relief device;

[0035] Figure 2 This is the reference diagram of the crack bifurcation of the sample during the bifurcation threshold test;

[0036] Figure 3 Schematic diagram of the temperature distribution of the long quartz tank in the crystallization upper limit temperature test;

[0037] Figure 4 This is a picture of the sample in the long quartz tank after the crystallization upper limit temperature test;

[0038] Figure 5 This is a scatter plot of the crystallization upper limit temperature distribution of the base glass in Examples 1 to 10 and Comparative Examples 1 to 8. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the embodiments described are only part of the embodiments of the present application, not all of them. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application are within the scope of protection of the present application.

[0040] Explanation of terms

[0041] Chemically strengthened glass is treated with a high-temperature ion exchange process. In a high-temperature salt bath, alkali metal ions with larger ionic radii replace smaller alkali metal ions in the glass, creating a volume difference between the exchanged ions. This creates a compressive stress that decreases from high to low on the surface of the base glass, hindering and slowing the growth of microcracks in the glass and ultimately increasing the mechanical strength of the glass.

[0042] Base glass: It is a glass matrix material that has not been strengthened.

[0043] Surface CS: Surface compressive stress / surface compressive stress. After chemical strengthening of glass, smaller alkali metal ions on the surface are replaced by larger alkali metal ions. Due to the crowding effect of the larger alkali metal ions, compressive stress is generated on the glass surface. Measured using the Orihara FSM-6000 stress meter from Japan.

[0044] DOL_0: Depth of the compressive stress layer, also known as the depth of the compressive stress layer, refers to the distance from any glass surface to the point near that surface where the compressive stress is zero. Measured using the Orihara SLP-2000 stress meter from Japan.

[0045] CT_LD: Tensile stress linear density. The ratio of the definite integral of the tensile stress curve of the strengthened glass to the thickness of the strengthened glass is recorded as the tensile stress linear density. The base glass is placed in a salt bath for ion exchange to form a strengthening layer (compressive stress layer / compressive stress layer). During the ion exchange process, a tensile stress layer forms within the glass. This tensile stress layer has an upper boundary spaced a certain distance from the upper surface of the chemically strengthened glass and a lower boundary spaced a certain distance from the lower surface of the chemically strengthened glass. The tensile stress curve is plotted with the tensile stress at a point on a line segment within the tensile stress layer perpendicular to both the upper and lower boundaries, with the upper and lower endpoints falling on the upper and lower boundaries, respectively, as the Y-axis and the distance from the corresponding point to the upper boundary as the X-axis. The tensile stress linear density is the ratio of the definite integral of the tensile stress curve to the thickness of the strengthened glass. This is also the ratio of the sum of the tensile stresses of the strengthened glass measured by the SLP-2000 stress meter to the glass thickness.

[0046] CT_LD max : The maximum tensile stress linear density (CT_LD) value that can be obtained by ion exchange chemical strengthening of the substrate glass under specific salt bath conditions is the maximum tensile stress linear density CT_LD that the substrate glass can obtain under the salt bath conditions. max This data can characterize the strengthening and ion exchange properties of the substrate glass.

[0047] During the chemical strengthening process, as the strengthening time increases, the tensile stress linear density (CT_LD) value of the substrate glass will first increase and then decrease. By continuously monitoring the changes in the tensile stress linear density inside the glass during the strengthening process, the maximum tensile stress linear density CT_LD that can be obtained under specific salt bath conditions can be determined. max .

[0048] Bifurcation threshold: The minimum linear tensile stress density of chemically strengthened glass prepared from a certain base glass formula when a glass crack bifurcates in an immediate fracture test is the bifurcation threshold of the chemically strengthened glass prepared from the base glass formula.

[0049] Immediate fracture test: The center point of the chemically strengthened glass sample is used as the breaking point, and a "stress release device" is used to generate a crack at the breaking point. The crack extends under the action of the internal tensile stress, such as Figure 2 When the chemically strengthened glass crack bifurcates, the minimum tensile stress linear density value of the chemically strengthened glass sample is the bifurcation threshold. Figure 1, where 1 represents the height adjustment rail, 2 represents the start adjustment rail, 3 represents the indenter, and 4 represents the chemically strengthened glass sample; the device uses pneumatic impact, and the probe uses a Vickers diamond indenter and is fixed with a rail to ensure that the indenter impacts the glass surface vertically. It is also equipped with a pressure sensor, which controls the impact force in combination with air pressure regulation, so that the destruction point only induces delayed fracture or only extends two cracks instead of producing a starburst, thereby minimizing the influence of external forces on the destruction state.

[0050] A certain number of substrate glass products were strengthened under the same salt bath conditions and subjected to different ion exchange times to obtain glass samples with different tensile stress linear densities. Immediate fracture tests were then performed on these strengthened glass samples, rank order from low to high, to determine whether cracks bifurcated. The minimum tensile stress linear density (CT_LD) corresponding to these bifurcated cracks was determined, representing the bifurcation threshold of the chemically strengthened glass prepared from this substrate glass. The bifurcation threshold is a reference indicator of the stress that can be safely tolerated by the glass.

[0051] Atomic packing density: how tightly atoms are packed inside the glass.

[0052] Upper limit of crystallization temperature: the highest temperature at which glass produces crystallization. Glass will not precipitate crystals above this temperature.

[0053] QF: Stress benefit, specifically refers to the stress effect generated by the introduction of 1 mg of sodium ions per unit area of glass during ion exchange in a salt bath.

[0054] The inventors of this application have discovered that existing lithium aluminum silicate chemically strengthened glass, which can achieve high stress levels and high mechanical properties, is generally unsuitable for mass production using the float process. This is because the high aluminum content in the base glass increases the glass's melting temperature, shortens the material properties, and increases the viscosity drop of the glass between 800°C and 1200°C. Furthermore, aluminum and lithium are the main components for the precipitation of spodumene crystals. Excessive aluminum and / or lithium content increases the upper crystallization temperature of the glass, causing crystallization defects and even devitrification during the float process, making it unsuitable for production using the float process. Therefore, the base glass typically used in mass production by the float process contains no more than 12 mol% of Al2O3 and Li2O, expressed as molar percentages of oxides. However, reducing the Al2O3 content is not conducive to improving the stress benefit generated by unit ion exchange, while reducing the Li2O content is not conducive to increasing the sodium ion-lithium ion exchange capacity, which in turn is not conducive to improving deep compressive stress and Young's modulus. Due to the limitation of float glass process, the content of Al2O3 and Li2O in the base glass suitable for float glass mass production is limited, which leads to the maximum tensile stress linear density CT_LD that can be obtained by chemical strengthening of the base glass of existing float glass mass production. max, maximum surface compressive stress CS max , which is lower than the existing base glass used to produce chemically strengthened glass with high stress levels and high mechanical properties. In other words, the mechanical strength of chemically strengthened glass made from base glass produced using the existing float process is relatively low. This, in turn, results in relatively low mechanical strength of products made from this chemically strengthened glass (such as mobile phone cover panels, aviation glass, automotive glass, etc.), which cannot meet actual needs.

[0055] Based on the above problems, the present application provides a substrate glass and a chemically strengthened glass made from the substrate glass, as well as a glass device comprising the substrate glass or the chemically strengthened glass, and an electronic device comprising the chemically strengthened glass.

[0056] A first aspect of the present application provides a substrate glass, wherein, expressed in molar percentage of oxides, the composition of the substrate 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%, and La2O3 0.10-3.00 mol%.

[0057] SiO2 and Al2O3 are the primary components of the glass network structure. Their addition helps improve the intrinsic strength of glass. SiO2 also enhances glass's acid resistance and reduces scratching, while Al2O3 enhances the stress benefits of ion exchange. However, excessive Al2O3 increases melting difficulty and raises the upper crystallization temperature. Excessive SiO2 also increases melting difficulty.

[0058] Y2O3 within the glass can cause changes in the glass network structure. The Si-OY bonds it forms reconnect the isolated island-like network structure within the glass, improving the glass structure and increasing its network stability. This in turn increases the unit stress generated by sodium-lithium exchange and enhances the stress benefit of ion exchange. Furthermore, due to Y's large relative atomic mass and radius, it exerts a high field strength within the glass network, aggregating the free alkali and alkaline earth metals within it, tightening the network structure and thus making the overall glass structure more compact and densified, thereby increasing the atomic packing density of the glass. Therefore, the presence of Y2O3 can also reduce the degree of structural relaxation after annealing, while also increasing the glass's Vickers hardness and scratch resistance. However, excessive Y2O3 can lead to an increase in the upper limit of glass crystallization and, by making the glass structure too dense, hinder ion exchange, affecting both the ion exchange rate and depth.

[0059] Alkali metals are the main components involved in ion exchange, Na ions are the key exchange ions for forming high surface 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 disconnect the bridging oxygen, destroy the network structure of the glass, and reduce the intrinsic strength of the glass. And since Li2O is the main component of lithium aluminum silicate crystallization, too much of it will increase the crystallization upper limit of the glass, causing production difficulties. Although the increase of Na2O can increase CS, reduce the crystallization tendency of lithium aluminum silicate glass, and lower the upper limit temperature of crystallization, too much will hinder sodium-lithium exchange, thereby reducing deep stress and affecting the drop resistance of the glass. The increase of K2O can reduce the upper limit temperature of crystallization, but excessive K ions will hinder the ion exchange rate, especially potassium-sodium ion exchange. Therefore, the content of each alkali metal oxide in the scheme needs to be strictly controlled.

[0060] Magnesium oxide (MgO) exists as a network intermediate, which has the effect of reducing the high-temperature viscosity of glass and increasing the Young's modulus of glass. Due to the small radius of the magnesium ion, it has a high filling density in the glass network structure, which has a significant effect on improving the Young's modulus. Also due to the small radius of the magnesium ion, it is the alkaline earth metal oxide with the least inhibitory effect on ion exchange. However, excessive magnesium oxide (MgO) will still hinder ion exchange.

[0061] The addition of La2O3 can reduce the crystallization tendency of lithium aluminosilicate glass formula containing only Y2O3, so as to obtain a lower upper limit of crystallization temperature. La2O3 can also further increase the density and intrinsic strength of the glass. However, when there is too much La2O3, it will affect the stress benefit generated by the unit exchange amount.

[0062] In some embodiments, the content of SiO2 can be 60.00mol%, 61.00mol%, 62.00mol%, 63.00mol%, 64.00mol%, 65.00mol%, 66.00mol%, 67.00mol%, 68.00mol%, 69.00mol%, 70.00mol%, 71.00mol%, 72.00mol%, 73.00mol%, 74.00mol%, 75.00mol% or a value within a numerical range consisting of any two of the above values as endpoints; it should be understood that, in the embodiment, any of the above ranges can be combined with any other ranges.

[0063] In some embodiments, the content of Al2O3 can be 8.00mol%, 8.50mol%, 9.00mol%, 9.50mol%, 10.00mol%, 10.50mol%, 11.00mol%, 11.50mol%, 12.00mol%, or a value within a numerical range consisting of any two of the above values as endpoints; it should be understood that, in the embodiment, any of the above ranges can be combined with any other ranges.

[0064] In some embodiments, the content of Li2O may 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 a numerical range consisting of any two of the above values as endpoints; it should be understood that, in embodiments, any of the above ranges may be combined with any other ranges.

[0065] In some embodiments, the content of Y2O3 can be 1.00mol%, 1.25mol%, 1.50mol%, 1.75mol%, 2.00mol%, 2.25mol%, 2.50mol%, 2.75mol%, 3.00mol% or a value within a numerical range consisting of any two of the above values as endpoints; it should be understood that, in the embodiment, any of the above ranges can be combined with any other ranges.

[0066] In some embodiments, 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 a numerical range consisting of any two of the above values as endpoints; it should be understood that, in the embodiment, any of the above ranges can be combined with any other ranges.

[0067] In some embodiments, the MgO content may 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 a numerical range consisting of any two of the above values as endpoints; it should be understood that, in the embodiment, any of the above ranges may be combined with any other ranges.

[0068] In some embodiments, the content of La2O3 may 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 a numerical range consisting of any two of the above values as endpoints. It should be understood that, in embodiments, any of the above ranges may be combined with any other ranges.

[0069] The substrate glass provided in this application, through an optimized formulation, not only meets the requirements of float glass mass production, for example, the substrate glass has a crystallization temperature of less than 1200°C and the glass liquid has an appropriate viscosity during the preparation process, but also has a high ion exchange stress benefit. When using this substrate glass to prepare chemically strengthened glass, high stress benefits can be achieved at a low sodium-lithium exchange rate, resulting in excellent mechanical strength. Furthermore, due to the high ion exchange stress benefit of the substrate glass in this application, when chemically strengthened in a salt bath, the substrate glass releases less lithium ions into the salt bath than existing lithium aluminosilicate glass, which helps to increase the service life of the salt bath. Furthermore, a reduced ion exchange rate helps reduce the discreteness of the drop height distribution of batch samples, ensuring the stable strength performance of mass-produced chemically strengthened glass. A high ion exchange rate can easily cause excessive volume changes in the surface layer of the substrate glass after strengthening, which can easily lead to large discreteness in the drop height distribution of batch samples and unstable strength performance in mass production.

[0070] In this application, base glass refers to unstrengthened glass; ion exchange stress benefit refers to the stress effect produced by exchanging the same number of ions during chemical strengthening. Ion exchange stress benefits vary depending on the glass structure. Generally speaking, the higher the ion exchange stress benefit, the less ion exchange required to achieve a high level of stress.

[0071] In some embodiments of the present application, the composition of the substrate glass, expressed as a molar percentage of oxides, satisfies the following conditions: La2O3 / Y2O3 is 0.2 to 1.0, preferably 0.2 to 0.8. Y2O3 is beneficial for improving the stress benefit QF generated by the substrate glass during ion exchange. The addition of La2O3 can reduce the crystallization tendency of lithium aluminosilicate glass formulations containing only Y2O3, thereby achieving a lower upper crystallization temperature. La2O3 can also further increase the density and intrinsic strength of the glass. However, excessive La2O3 can reduce the stress benefit generated per unit exchange amount. By regulating the La2O3 / Y2O3 ratio 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 a numerical range consisting of any two of the above values as endpoints, it is possible to lower the upper limit crystallization temperature of the substrate glass while ensuring that the Young's modulus and stress efficiency QF of the substrate glass meet the requirements, thereby facilitating float glass production and obtaining a substrate glass with a higher Young's modulus.

[0072] In some embodiments of the present application, expressed as a molar percentage of oxides, Al2O3+Li2O≤22.00mol%, preferably, Al2O3+Li2O≤20.00mol%. Al2O3 and Li2O are the main components for precipitating spodumene crystals. Excessive contents of Al2O3 and Li2O can increase the upper limit of crystallization temperature, causing crystallization defects and even devitrification of the glass during the float process. By regulating the contents of Al2O3 and Li2O within the above ranges, for example, Al2O3+Li2O can be 16.00mol%, 17.00mol%, 18.00mol%, 19.00mol%, 20.00mol%, 21.00mol%, 22.00mol%, or a value within a range consisting of any two of the above values as endpoints, this not only helps to lower the upper limit of crystallization temperature of the substrate glass, ensuring that the glass liquid has a longer material property and is better suited for the float process, but also can, to a certain extent, ensure the stability of the glass structure and the lithium ion exchange capacity during chemical strengthening.

[0073] In some embodiments of the present application, the composition of the substrate glass further comprises, expressed as a molar percentage of oxides, 0-3.00 mol% SrO, preferably 0-2.00 mol% SrO, and more preferably 0.50-2.00 mol% SrO. The addition of SrO helps reduce the crystallization tendency of the lithium aluminosilicate glass and the crystallization rate during crystallization, further avoiding the occurrence of crystallization. However, excessive strontium oxide (SrO) can hinder ion exchange. By regulating the SrO content within the above range, for example, the SrO content 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 a numerical range consisting of any two of the above values as endpoints, the occurrence of crystallization can be further avoided.

[0074] In some embodiments of the present application, the MgO and SrO contents, expressed as molar percentages of oxides, satisfy SrO / (MgO+SrO) ≤ 0.35, preferably 0.05 ≤ SrO / (MgO+SrO) ≤ 0.35. By regulating the SrO / (MgO+SrO) value within the aforementioned range, for example, the SrO / (MgO+SrO) value 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 range of values consisting of any two of the aforementioned values, this helps ensure the ion exchange rate during the chemical strengthening process of the substrate glass and avoids excessive strengthening time. The aforementioned chemical strengthening process is also the process of ion exchange of the substrate glass in a salt bath.

[0075] In some embodiments of the present application, the composition of the substrate glass further includes, expressed as a molar percentage of oxides, 0-3.00 mol% of K2O, preferably 1.00-3.00 mol% of K2O, and more preferably 1.00-2.00 mol% of K2O. The addition of K2O helps lower the upper crystallization temperature, but excessive K2O content can affect the ion exchange stress benefit. By regulating the K2O content within the aforementioned range, for example, the K2O content can be 0.00 mol%, 0.50.00 mol%, 1.00 mol%, 1.50 mol%, 2.00 mol%, 2.50 mol%, 3.00 mol%, or a range consisting of any two of the aforementioned values, the upper crystallization temperature can be lowered while ensuring that the ion exchange stress benefit meets the requirements.

[0076] In some preferred embodiments of the present application, the composition of the substrate glass, expressed in molar percentage of oxides, includes: 64.00-70.00 mol% SiO2, and / or 8.00-12.00 mol% Li2O, and / or 4.00-6.00 mol% Na2O, and / or 2.00-7.50 mol% MgO, and / or 0.20-1.50 mol% La2O3. In other words, the composition of the substrate glass satisfies at least one of 64.00-70.00 mol% SiO2, 8.00-12.00 mol% Li2O, 4.00-6.00 mol% Na2O, 2.00-7.50 mol% MgO, and 0.20-1.50 mol% La2O3. Further optimization of the base glass formula can not only better meet the requirements of float glass mass production, effectively avoid the occurrence of crystallization and increase the service life of the salt bath, but also help to obtain chemically strengthened glass with higher mechanical strength.

[0077] In some preferred embodiments of the present application, the composition of the substrate glass, expressed in molar percentage of oxides, includes: 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%, and La2O3 0.10-3.00 mol%.

[0078] In some preferred embodiments of the present application, the composition of the substrate glass, expressed in molar percentage of oxides, includes: 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.

[0079] In some preferred embodiments of the present application, the composition of the substrate glass, expressed in molar percentage of oxides, includes: 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%, and La2O3 0.20-1.50 mol%.

[0080] The upper crystallization temperature limit of the substrate glass in any of the above embodiments of the present application is less than or equal to 1185°C, preferably less than or equal to 1165°C. For example, the upper crystallization temperature limit of the substrate glass can be 900°C, 950°C, 1000°C, 1100°C, 1150°C, 1165°C, 1180°C, 1185°C, or a value within a range of values consisting of any two of the above values. This upper crystallization temperature limit meets the production requirements of the float glass process, and thus the substrate glass provided in this application can be mass-produced using the float glass process.

[0081] The substrate glass in any of the above embodiments of the present application is ion exchanged with a substrate glass of 0.7 mm thickness, and ion exchange is carried out in a 100 wt% NaNO3 salt bath at 450°C to 1 cm 2 When 1 mg of sodium ions is introduced into the substrate glass by exchange, the resulting stress benefit QF is greater than or equal to 90,000 MPa / mm, preferably greater than or equal to 95,000 MPa / mm and less than or equal to 200,000 MPa / mm. For example, the stress benefit QF can be 90,000 MPa / mm, 92,500 MPa / mm, 95,000 MPa / mm, 97,500 MPa / mm, 100,000 MPa / mm, 125,000 MPa / mm, 150,000 MPa / mm, 175,000 MPa / mm, 200,000 MPa / mm, or a value within a range of values consisting of any two of the foregoing values. When the substrate glass undergoes ion exchange, the greater the stress benefit QF value per unit area, the easier it is to prepare chemically strengthened glass with high stress levels and mechanical strength. In addition, when preparing chemically strengthened glass with high stress levels and mechanical strength, the required amount of ion exchange is also less, which can reduce the amount of lithium ions released into the salt bath and effectively increase the service life of the salt bath.

[0082] The substrate glass in any of the above embodiments of the present application is ion exchanged with a substrate glass of 0.7 mm thickness, and the maximum tensile stress linear density CT_LD obtained in a 100 wt% NaNO3 salt bath at 450°C is max Greater than or equal to 50000 MPa / mm, preferably 50000 MPa / mm to 90000 MPa / mm. For example, the maximum tensile stress linear density CT_LD max The maximum tensile stress linear density CT_LD may be 50000 MPa / mm, 55000 MPa / mm, 60000 MPa / mm, 65000 MPa / mm, 70000 MPa / mm, 75000 MPa / mm, 80000 MPa / mm, 85000 MPa / mm, 90000 MPa / mm, or a value within a numerical range consisting of any two of the above values as endpoints. maxThe higher the value, the better the strengthening and ion exchange properties of the base glass. Using this base glass, chemically strengthened glass with high tensile stress linear density can be produced, ensuring that the chemically strengthened glass has excellent drop resistance.

[0083] The substrate glass in any of the above embodiments of the present application obtains the maximum tensile stress linear density CT_LD in a 100wt% NaNO3 salt bath at 450°C. max When the compressive stress layer depth DOL_0 formed on the substrate glass is 0.15t to 0.22t, where t is the thickness of the substrate glass. The change in glass thickness before and after chemical strengthening is very small and negligible. Therefore, in this application, the thickness of the substrate glass is used as the thickness of the chemically strengthened glass. For example, the compressive stress layer depth DOL_0 can be 0.15t, 0.16t, 0.17t, 0.18t, 0.19t, 0.20t, 0.21t, 0.22t, or a value within a range of values defined by any two of these values. The compressive stress layer depth DOL_0 is measured using an SLP-2000 stress meter. When the compressive stress layer depth DOL_0 is within the above range, the compressive stress layer is sufficiently deep. When the glass contacts a sharp object, this compressive stress layer can better prevent cracks from entering the tensile stress layer, thereby improving drop resistance. The substrate glass thickness t can be selected based on the desired thickness of the chemically strengthened glass and is not limited in this application. Illustratively, the thickness of the substrate glass may be 0.4 to 2.0 mm.

[0084] In any of the above embodiments of the present application, the substrate glass is ion exchanged with a 0.7 mm thick substrate glass. When the substrate glass obtains the maximum tensile stress linear density CT_LD in a 100 wt% NaNO3 salt bath at 450°C, max When the amount of lithium ions released from the substrate glass into the salt bath is less than or equal to 1.00 mg / cm 2 For example, the amount of lithium ions released by the substrate glass into the salt bath can be 0.10 mg / cm 2 , 0.20mg / cm 2 , 0.30mg / cm 2 , 0.40mg / cm 2 , 0.50mg / cm 2 , 0.60mg / cm 2 , 0.70mg / cm 2 , 0.80mg / cm 2 , 0.90mg / cm 2 、1.00mg / cm 2or a value within a range defined by any two of the aforementioned values. This demonstrates that when the substrate glass provided herein undergoes ion exchange to obtain chemically strengthened glass with high stress levels and mechanical properties, the amount of lithium ions released into the salt bath is relatively small, thereby improving the salt bath's service life. During mass production, this increased salt bath service life helps reduce production costs, indicating that the substrate glass provided herein is suitable for mass production of chemically strengthened glass. Furthermore, the low amount of ion exchange helps ensure minimal dispersion in the drop height distribution of batch samples, ensuring stable strength performance in mass-produced chemically strengthened glass.

[0085] In any of the above embodiments of the present application, the substrate glass is subjected to ion exchange with a thickness of 0.7 mm. When the depth of ion exchange of the substrate glass is 4.9 to 5.1 μm in a 100 wt% KNO3 salt bath at 430°C, the surface compressive stress CS of the substrate glass is obtained. max Greater than or equal to 1000 MPa, preferably 1000 MPa to 1600 MPa. The surface compressive stress CS obtained by the substrate glass max The compressive stress CS generated on the surface of the substrate glass in a 100wt% KNO3 salt bath at 430°C can be 1000MPa, 1050MPa, 1100MPa, 1150MPa, 1200MPa, 1250MPa, 1300MPa, 1350MPa, 1400MPa, 1450MPa, 1500MPa, 1550MPa, 1600MPa, or a value within a range of values consisting of any two of the above values as endpoints. max The larger the value, the greater the surface compressive stress that can be obtained when the substrate glass is used to prepare chemically strengthened glass using other salt baths, and the better the mechanical strength of the obtained chemically strengthened glass.

[0086] The Young's modulus of the substrate glass in any of the above-described embodiments of the present application is greater than or equal to 85 GPa, preferably greater than or equal to 90 GPa and less than or equal to 100 GPa. For example, the Young's modulus of the substrate glass can be 85 GPa, 86 GPa, 87 GPa, 88 GPa, 89 GPa, 90 GPa, 95 GPa, 100 GPa, or a range of values consisting of any two of these values. The substrate glass provided herein has a relatively high Young's modulus, and thus, the chemically strengthened glass produced using the substrate glass provided herein has excellent mechanical strength.

[0087] In some embodiments of the present application, the atomic packing density of the substrate glass is greater than or equal to 0.552 and less than or equal to 0.620. For example, the atomic packing density of the substrate glass can be 0.552, 0.555, 0.560, 0.565, 0.570, 0.575, 0.580, 0.585, 0.595, 0.600, 0.605, 0.610, 0.620, or a value within a range of values defined by any two of the aforementioned values as endpoints. The high atomic packing density of the substrate glass and the high network integrity and density of the substrate glass are further beneficial for improving the ion exchange stress resistance of the glass, as well as improving the glass's Vickers hardness, Young's modulus, drop resistance, bifurcation threshold, and other properties. When chemically strengthened, this substrate glass is advantageously capable of obtaining chemically strengthened glass with high stress levels and excellent mechanical strength.

[0088] In some embodiments of the present application, the bifurcation threshold of the substrate glass is greater than or equal to 40,000 MPa / mm, preferably between 40,000 MPa / mm and 60,000 MPa / mm. For example, the bifurcation threshold of the substrate glass can be 40,000 MPa / mm, 42,000 MPa / mm, 44,000 MPa / mm, 45,000 MPa / mm, 47,000 MPa / mm, 50,000 MPa / mm, 52,000 MPa / mm, 54,000 MPa / mm, 55,000 MPa / mm, 57,000 MPa / mm, 60,000 MPa / mm, or a value within a range of values defined by any two of the aforementioned values. The inventors of this application, through in-depth and systematic research on substrate glass and strengthening processes, discovered that lithium aluminosilicate glass, which can be used to prepare chemically strengthened glass with high stress resistance, must be able to withstand the stresses caused by chemical strengthening. If the stress tolerance limit is too low, the stress effect achieved by chemical strengthening will be extremely limited. The bifurcation threshold is a reference indicator for whether the substrate glass can safely accommodate stress. It is an inherent characteristic of the substrate glass itself and will not change with changes in the strengthening conditions of the substrate glass. It will only change with changes in the formulation of the substrate glass. Therefore, the bifurcation threshold becomes a characteristic parameter for determining whether the substrate glass can be used to prepare chemically strengthened glass with high stress levels.

[0089] In applications such as mobile phone covers, the higher the tensile stress linear density CT_LD value obtained by the base glass after ion exchange, the stronger its drop resistance. However, the more the CT_LD value exceeds the bifurcation threshold of the glass, the more small fragments the glass sample will produce after the cover glass shatters. If you want the cover glass to remain in larger fragments when it shatters and continue to be used without immediate failure, you need to control the CT_LD value not to exceed the bifurcation threshold too much. Therefore, to ensure that the chemically strengthened glass used for mobile phone covers has excellent drop resistance, in addition to ensuring that the base glass used can obtain a sufficient maximum tensile stress linear density CT_LD in a 100wt% NaNO3 salt bath at 450°C, max In addition, it is also necessary to ensure that the substrate glass used has a high bifurcation threshold. The higher the bifurcation threshold, the higher the stress level of the chemically strengthened glass that can be produced from the substrate glass, and the better the drop resistance. Using the substrate glass provided in this application, chemically strengthened glass with excellent drop resistance can be produced.

[0090] The second aspect of the present application provides a chemically strengthened glass, which is obtained by placing the substrate glass of any of the above embodiments in a salt bath and subjecting it to ion exchange chemical strengthening. The chemically strengthened glass comprises a compressive stress layer and a tensile stress layer. The chemically strengthened glass has a compressive stress layer formed on the surface by chemically strengthened ion exchange and a tensile stress layer inside that is capable of achieving force balance with the compressive stress layer. In some embodiments of the present application, the composition of the tensile stress layer is the same as that of the substrate glass of any of the above embodiments. The present application does not limit the parameters (such as temperature and time) for chemically strengthening the substrate glass in the salt bath; parameters known in the art may be used as long as the objectives of the present application are achieved. The present application does not limit the type of salt bath; salt baths known in the art may be used as long as the objectives of the present application are achieved.

[0091] A third aspect of this application provides a glass device, which is made from the substrate glass described in any of the aforementioned embodiments or the chemically strengthened glass described in any of the aforementioned embodiments. For example, the glass device may include, but is not limited to, a mobile phone display cover, a mobile phone battery back cover, a laptop screen cover, and an automotive center console glass cover. The substrate glass and chemically strengthened glass provided herein have excellent mechanical strength, and thus the glass device provided herein also has excellent mechanical strength.

[0092] A fourth aspect of the present application provides an electronic device comprising the chemically strengthened glass of any of the aforementioned embodiments. For example, the electronic device may include, but is not limited to, a mobile phone, a tablet computer, a smart wearable device (e.g., an electronic watch, a smart bracelet, a smart watch, smart glasses, etc.), a display (e.g., a high-definition display, an in-vehicle display, an in-flight display, etc.), a television, and the like.

[0093] Illustratively, an electronic device may include a housing and an electronic component partially located within the housing, the housing including a front surface, a rear surface, and side surfaces, the electronic component including a display device, the display device being located at or adjacent to the front surface of the housing, and the chemically strengthened glass provided in the present application may be applied to the front surface and / or the rear surface and / or the side surface of the housing; preferably, the electronic device may further include a covering product covering the front surface of the housing or located on the display device, and the chemically strengthened glass provided in the present application may be applied to the covering product.

[0094] Test method:

[0095] 1. Testing method of stress parameters

[0096] Test conditions for surface CS and potassium-sodium stress exchange depth: A Japanese Orihara FSM-6000 stress meter was used, with a light source wavelength of 596 nm. Before testing, the thickness, refractive index, and photoelastic coefficient of the sample to be tested were entered into the parameter table. The test was then performed to obtain the stress parameter values for the sample.

[0097] DOL_0 and CT_LD test conditions: Tests were conducted using an Orihara SLP-2000 stress meter (Japan) with a light source wavelength of 518nm. Before testing, the thickness, refractive index, and photoelastic coefficient of the sample were entered into the parameter table. The exposure time was adjusted to 5000 usec before testing to obtain the stress parameter values for the sample.

[0098] Glasses of different compositions have different refractive indices and photoelastic coefficients. 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.

[0099] When using a stress meter to measure the stress parameters of chemically strengthened glass samples, first place a drop of the instrument's dedicated refractive fluid on the instrument. Then, clean the chemically strengthened glass and place it in the test path. The instrument settings are configured according to the aforementioned test conditions before testing to obtain the stress parameter values for the chemically strengthened glass. The refractive fluid used in the SLP-2000 has a refractive index of 1.51, while the refractive fluid used in the FSM-6000 has a refractive index of 1.72.

[0100] 2. Test of the upper limit temperature of crystallization

[0101] The substrate glass was broken into small pieces of 2 mm to 5 mm in size, and then placed into the long quartz tank and filled.

[0102] The gradient furnace model JKZC-XJY01 is set to a temperature range, such as a temperature range of 1050°C to 1225°C, and at least 6 temperature points are selected from high to low in each temperature range.

[0103] After the gradient furnace reaches the preset temperature range, place the long quartz tank with the sample into the gradient furnace so that the six temperature points correspond to the glass samples at six positions in the long quartz tank. Figure 3 Place the long quartz tank in a gradient furnace and keep it at a constant temperature for 60 to 70 minutes, then take it out.

[0104] Observe the glass samples at different positions in the long quartz tank. If the glass sample becomes devitrified or foggy, it is determined that the glass sample at that position has crystallized. If the glass sample is completely transparent, it is determined that the glass sample at that position has not crystallized. Figure 4 , Figure 4 In a long quartz cell, the upper area is a completely transparent sample, the lower area is a devitrified sample, and there is a foggy sample between the completely transparent and devitrified samples. Observation can be aided by tools such as a magnifying glass or microscope.

[0105] Determination of the upper limit temperature of crystallization: The upper limit temperature range of crystallization is between the temperature point corresponding to the completely transparent sample and the temperature point corresponding to the adjacent devitrified or foggy sample. The average value of the two temperature points is taken as the upper limit temperature of crystallization.

[0106] If all the glass samples in the long quartz tank crystallize within the temperature range set by the gradient furnace, the upper limit temperature of the gradient furnace temperature range is reset, and the upper limit temperature of crystallization of the glass samples is measured. If none of the glass samples in the long quartz tank crystallize within the temperature range set by the gradient furnace, the lower limit temperature of the gradient furnace temperature range is reset, and the upper limit temperature of crystallization of the glass samples is measured.

[0107] 3. Stress Benefit QF Test

[0108] The initial mass of a glass substrate (50 mm x 50 mm x 0.7 mm) was measured using a Shimadzu precision balance (AUW120D, with an accuracy of one ten-thousandth of a gram). Ion exchange was then performed in a 100 wt% NaNO3 salt bath at 450°C. The glass was removed every hour, cleaned, and its mass and tensile stress linear density (CT_LD) were measured and recorded. After each test, the glass was reinserted into the bath for further strengthening and then removed for testing at the next test time.

[0109] During the ion exchange process, the sodium ions in the salt bath are exchanged with the lithium ions in the glass, so the glass will produce a mass increment W. The mass increment W is the mass increment brought about by the exchange of sodium ions for lithium ions, that is, W = MNa ×n Na -M Li ×n Li , where M Na 、M Li are the relative atomic masses of sodium and lithium, n Na and n Li is the amount of sodium ions and lithium ions exchanged. The mass of sodium ions in the salt bath participating in the exchange W Na =M Na ×n Na Since the amount of sodium ions and lithium ions exchanged is the same, that is, n Na =n Li , so n Na =W / (M Na -M Li ). Then W Na =M Na *W / (M Na -M Li ). The relative atomic mass of sodium is 23, and the relative atomic mass of lithium is 7. Finally, W is calculated. Na =1.4375W.

[0110] During the ion exchange process, due to the different ionic radii of sodium ions and lithium ions, compressive stress will be generated on the glass surface. In order to balance the generated compressive stress, tensile stress will be generated inside the glass. Therefore, the strengthened glass will obtain a tensile stress linear density CT_LD.

[0111] Because the high temperature exchange environment will weaken the fixed stress generated by the exchange, that is, stress relaxation. Therefore, the tensile stress linear density value obtained by the glass should be the value after deducting the stress relaxation from the stress benefit generated by the exchange.

[0112] Assuming that the stress relaxation generated per hour during the ion exchange process is QW, then

[0113]

[0114] Where S is the area of any one of the two surfaces of the substrate glass facing each other along its thickness direction, in cm 2 ; W is in mg; T is time in h.

[0115] For example: the maximum compressive stress CT_LD will be reached max The mass increment at this time is recorded as W max , time is recorded as T max The mass increase after ion exchange for 1 hour is recorded as W1, the time is recorded as T1, and the compressive stress is recorded as CT_LD T1The mass increase after ion exchange for 2 hours is recorded as W2, the time is recorded as T2, and the compressive stress is recorded as CT_LD T2 , and so on, the mass increase after ion exchange for n hours is recorded as W n , time is recorded as T n , compressive stress is recorded as CT_LD Tn .

[0116] For example, as in T1 and T max Under QF and QW, we can get two formulas as follows

[0117] CT_LD T1 =QF×1.4375×W1 / 2S-T1×QW Formula Ⅰ

[0118] CT_LD max =QF×1.4375×W max / 2S-T max ×QW Formula II

[0119] Let T max / T1=a,Formula II-a×Formula I then obtains:

[0120] CT_LD max -a×CT_LD T1 =QF×1.4375×W max / 2S-a×QF×1.4375×W1 / 2S

[0121] Then QF=(CT_LD max -a×CT_LD T1 ) / (1.4375×W max / 2S-a×1.4375×W1 / 2S), and T1 and T max The QF under is denoted as QF (T1-max) By analogy, the same calculation method can be used to obtain QF (T2-max) ...QF (Tn-max) .

[0122] Finally calculate QF (T1-max) , QF (T2-max) ...QF (Tn-max) The average value is taken as QF value. QF represents the stress benefit generated by exchanging 1mg sodium ions per square centimeter.

[0123] 4. Maximum tensile stress linear density CT_LD max Test

[0124] In the present invention, a 100wt% sodium nitrate bath at 450°C is used as the test CT_LD maxUnder the salt bath conditions, SLP-2000 stress meter was used as the testing instrument for testing the tensile stress linear density CT_LD.

[0125] The specific method is as follows: the substrate glass sample to be tested is placed in a 100wt% sodium nitrate salt bath at 450°C for chemical strengthening. During the strengthening period, the glass sample is taken out every 0.5h to test its internal CT_LD value. After each glass sample is taken out and tested, the glass sample is immediately placed in the salt bath and continued to be strengthened. When the next test time point is reached, the glass sample is taken out for testing again, and the above test process is repeated, and the CT_LD value of the test is recorded. When it is found that the measured CT_LD value begins to decrease after increasing to a certain value m, the value m is determined to be the maximum tensile stress linear density CT_LD that can be obtained by the substrate glass sample under the salt bath conditions (100wt% sodium nitrate salt bath at 450°C). max .

[0126] Note: Each time the tensile stress linear density CT_LD value is tested, other data measured on the instrument, such as DOL_0, should be recorded to facilitate the determination of CT_LD max When the value is determined, the glass obtains the maximum value of the tensile stress linear density CT_LD max The depth of the compressive stress layer that can be reached.

[0127] 5. Test of the amount of lithium ions released in the salt bath

[0128] The mass of the substrate glass (length, width and thickness of 50 mm × 50 mm × 0.7 mm) was measured using a Shimadzu precision balance, which was recorded as m1. The accuracy of the balance was one ten-thousandth of a gram, and the balance model was AUW120D.

[0129] After ion exchange in a 100wt% NaNO3 salt bath at 450℃ for t hours, the substrate glass is taken out and cleaned with deionized water. The mass of the substrate glass is then measured to be m2. Among them, t hours is the maximum value of the tensile stress linear density CT_LD. max The processing time can be calculated based on the maximum value of the tensile stress linear density CT_LD max The test is obtained.

[0130] The mass increase of the substrate glass before and after ion exchange is the mass increase caused by the exchange of sodium ions for lithium ions, △w = m2 - m1, in mg. In addition, sodium ions and lithium ions are exchanged in equimolar amounts, so △w = M Na ×nM Li ×n, so n=△w / (M Na -M Li ), the amount of lithium ions released in the salt bath = M Li ×n. Among them, M NaThe relative atomic mass of sodium is 23, M Li is the relative atomic mass of lithium 7, n is the number of moles of sodium ions or lithium ions exchanged. After calculation, it can be seen that the maximum value of the tensile stress linear density CT_LD is obtained max When the 0.7mm thick substrate glass releases lithium ions into the salt bath = M Li ×△w / (M Na -M Li ).

[0131] 6. Test of Young's modulus

[0132] A glass substrate (25 mm x 85 mm x 2.5 mm) was placed on the test instrument and vibrated with the tip. A receiver placed at the upper end detected the ultrasonic vibration propagation results, and the instrument then measured the Young's modulus. The test instrument used in this invention is manufactured by Kegonas Instrument Trading Co., Ltd., model MK7.

[0133] 7. Test of atomic packing density

[0134] The atomic packing density is calculated as:

[0135]

[0136] in:

[0137] ρ is the density of the substrate glass, unit: g / cm 3 , tested using the Archimedes drainage method, and the test environment is 25℃.

[0138] Mtotal=Ma+Mb+...+Mx;

[0139] Where: Ma, Mb...Mx are the molar masses of the oxide components in the glass. For example, the molar fraction of oxide a in the substrate glass is Mol a The relative molecular mass of the oxide is F ma , the molar fraction of oxide b in the substrate glass is Mol b The relative molecular mass of the oxide is F mb , the mole fraction of oxide x in the substrate glass is Mol x The relative molecular mass of the oxide is F mx .

[0140] Ma=Mol a ×F ma , Mb=Mol b ×F mb , Mx=Mol x ×F mx .

[0141] Vtotal = Va + Vb + ... + Vx;

[0142] Where: Va, Vb...Vx are the molar volumes of the oxides in the glass. For example, the molar fraction of oxide a in the glass is Mol a , the oxide in the glass is X ⅰ Y ⅱ , the molecular volume of its oxide is F Va =(4×π / 3)×NA×(ⅰ×r x 3 +ⅱ×r Y 3 )×10 -21 ,

[0143] Va=Mol a ×F va , and so on for other oxides b...oxide x to obtain Vb...Vx.

[0144] NA is Avogadro's constant 6.02×10 23 , r x 、r Y They are the ionic radius of cations and anions in oxides (the ionic radius here refers to the Pauling ion radius), and the unit is nm.

[0145] 8. Testing of the Bifurcation Threshold

[0146] First, the maximum tensile stress linear density CT_LD that can be obtained in a 100wt% sodium nitrate bath at 450°C for a substrate glass with a thickness of 0.7mm corresponding to a certain glass formula is tested. max Then, chemically strengthened glass samples with different CT_LD were strengthened under the salt bath conditions, ranging from 30000MPa / mm to CT_LD max , with an increase of about 1000MPa / mm, 1500MPa / mm or 2000MPa / mm, and the CT_LD is obtained by testing with an SLP-2000 stress meter. For example, the substrate glass with a thickness of 0.7mm corresponding to the glass formula to be tested is strengthened under the above-mentioned salt bath conditions, that is, a 100wt% sodium nitrate salt bath at 450°C, to obtain chemically strengthened glass samples with CT_LD of about 30000MPa / mm, about 31000MPa / mm, about 32000MPa / mm, about 33000MPa / mm, about 34000MPa / mm, and about 36000MPa / mm. These chemically strengthened glass samples are then subjected to fracture experiments in order of CT_LD values from low to high. The center point of the chemically strengthened glass sample is used as the destruction point, and a "stress release device" (see Figure 1 ), causing cracks to form at the failure point.

[0147] A chemically strengthened glass sample with crack bifurcation is selected, and the minimum CT_LD value of the chemically strengthened glass sample with crack bifurcation is used as the bifurcation threshold of the chemically strengthened glass prepared from the base glass of the formula.

[0148] When the CT_LD of the chemically strengthened glass sample has reached CT_LD max , and an immediate fracture test is performed on the glass sample. If it is found that the crack of the glass sample still does not bifurcate, it is judged that the bifurcation threshold of the chemically strengthened glass prepared by this formula base glass is greater than the maximum tensile stress linear density CT_LD that can be obtained by the base glass of this formula in a 100wt% sodium nitrate salt bath at 450℃ max .

[0149] 9. Anti-drop height test

[0150] Average sandpaper drop resistance: The value obtained by dividing the sum of the sandpaper drop resistance heights measured for multiple glass samples by the number of samples measured. It is used to indicate the glass's resistance to contact surface cracking.

[0151] Take at least 10 samples from each batch for testing, and the average resistance to sandpaper drop height

[0152]

[0153] Where n is the number of glass samples tested in each batch, and hi is the sandpaper drop resistance height of a single sample tested.

[0154] Among them, the test method for the sample's resistance to sandpaper drop height is:

[0155] Step 1: Place the glass sample to be tested, which is 158.8mm x 72.8mm x 0.7mm in length, width and thickness, on the front of a 200g model machine.

[0156] Step 2: Place the model phone on a Green Figure LT-SKDL-CD drop machine with the glass sample facing the sandpaper. Drop it from a certain drop height, impacting the 120-grit sandpaper directly below the model phone, to simulate a normal mobile phone drop.

[0157] If the glass sample does not break, the drop height of the model machine is increased in a certain pattern. For example, the drop height starts from 0.4m and the sample is dropped once. If it does not break, the drop height is increased by 0.1m each time until the glass sample breaks.

[0158] Step 3: Record the last drop height of the glass sample when it breaks as the sandpaper drop height. For example, if the drop height when it breaks is 0.5m, the sandpaper drop height of the sample is 0.4m.

[0159] B10 of sandpaper drop resistance: This is a statistical value calculated using a Weibull distribution. It analyzes sandpaper drop resistance data from multiple samples, taking into account the discreteness of the sandpaper drop resistance distribution. In this application, B10 specifically refers to the sandpaper drop resistance of a chemically strengthened glass sample with a 10% failure rate. It can be used to evaluate the drop resistance of a specific chemically strengthened glass.

[0160] Calculation of B10 against sandpaper drop height:

[0161] Take the measured sandpaper drop resistance of m pieces of chemically strengthened glass and record them as N1 to Nm. Then, set the parameter K of the PERCENTILE function to 0.1 and use this function to calculate the data from N1 to Nm. The result is recorded as the B10 value of the sandpaper drop resistance.

[0162] 10. Test of chemically strengthened glass CT_LD

[0163] The sum of the tensile stress of the chemically strengthened glass was tested using an SLP-2000 stress meter, and the ratio of the tested sum of the tensile stress to the glass thickness was calculated, which is the tensile stress linear density CT_LD of the chemically strengthened glass.

[0164] Example 1

[0165] According to the formula 1 in Table 1, the material design is converted into the glass production raw material formula for ingredient preparation, with a total mass of 1600 g, and 0.4wt% (based on the total mass of formula 1) of clarifier sodium chloride is added. It is placed in a platinum crucible and heated to 1650°C in a high-temperature melting furnace to melt for 10 hours. Then it is poured into a molding mold and cooled to form. After cooling to 800°C, it is placed in an annealing furnace and annealed at 560°C for 2000 minutes. Then, it is cooled to 500°C in 300 minutes and kept warm for 300 minutes. Then, it is cooled to 400°C, 300°C, and 200°C in this cooling method in sequence to achieve gradient slow cooling. It is then cooled to room temperature with the furnace to obtain a glass sample brick.

[0166] Then, the glass sample brick is subjected to multi-wire cutting, CNC, thinning, and polishing to obtain substrate glass, and the thickness of the substrate glass is 0.7 mm.

[0167] Example 2 to Example 10

[0168] Except that Formula 1 is replaced by Formulas 2 to 10 in Table 1 in sequence, the rest is the same as Example 1.

[0169] Example 11

[0170] The substrate glass in Example 1 was first treated in a 100 wt % NaNO 3 salt bath at 430° C. for 2 h, and then treated in a 100 wt % KNO 3 salt bath at 430° C. for 0.5 h to obtain chemically strengthened glass. The thickness of the chemically strengthened glass was 0.7 mm.

[0171] Example 12 to Example 16

[0172] The above process is the same as Example 11 except that the substrate glass in Example 1 is replaced by the substrate glass in Examples 2 to 4 and 9 to 10, respectively, and the strengthening process is adjusted according to Table 4.

[0173] Comparative Examples 1 to 8

[0174] Except that Formula 1 is replaced by Formulas 11 to 18 in Table 1 in sequence, the rest is the same as Example 1.

[0175] Comparative Examples 9 to 15

[0176] Except that the substrate glass in Example 11 is replaced by the substrate glass in Comparative Examples 1 to 4 and Comparative Examples 6 to 8 in sequence, and the strengthening process is adjusted according to Table 4, the rest is the same as Example 11.

[0177] The parameters of each embodiment and comparative example are detailed in Table 2, and the performance test results are detailed in Table 3 and Table 4.

[0178] Table 1

[0179]

[0180] Note: The content of each substance in Table 1 is molar percentage, and “ / ” means the corresponding substance does not exist.

[0181] Table 2

[0182]

[0183]

[0184] Note: “ / ” in Table 2 indicates that there is no corresponding parameter.

[0185] Table 3

[0186]

[0187]

[0188] Note: “>42430” in Table 3 means that the tensile stress linear density is CT_LD according to the test method of the above bifurcation threshold. maxIn the immediate fracture test, the chemically strengthened glass did not produce crack bifurcation when it was broken. Therefore, it can be determined that the bifurcation threshold of the substrate glass prepared by the formula of Comparative Example 1 is greater than CT_LD max .

[0189] Table 4

[0190]

[0191] Note: In Table 4, taking Example 11 as an example, "430°C*100wt% NaNO3*2h 430°C*100wt% KNO3*0.5h" means that the substrate glass is first treated in a 100wt% NaNO3 salt bath at 430°C for 2h, and then treated in a 100wt% KNO3 salt bath at 430°C for 0.5h to obtain chemically strengthened glass. The same applies to other Examples and Comparative Examples.

[0192] Refer to Table 3 and Figure 5 From Examples 1 to 10, Comparative Examples 2, 4, 7, and 8, it can be seen that the upper limit of crystallization temperature of the substrate glass in the examples of the present application is less than 1180°C, so it can be produced by the float process, while the crystallization temperature in the comparative examples is greater than 1200°C, so it cannot be produced by the float process. At the same time, the stress benefit QF and the maximum tensile stress linear density CT_LD of the substrate glass obtained in the examples of the present application are max , depth of compressive stress layer DOL_0, amount of lithium ions released in the salt bath, surface compressive stress CS max , Young's modulus, atomic packing density and bifurcation threshold are comparable to those of the comparative example or some performances are better than those of the comparative example.

[0193] From Examples 1 to 10, Comparative Examples 1, 3, 5 and 6, it can be seen that although the crystallization temperature of the comparative examples does not exceed 1200°C and the float process can be used for production, the stress benefit QF and the maximum tensile stress linear density CT_LD of the substrate glass in the examples of the present application are max , depth of compressive stress layer DOL_0, surface compressive stress CS max , Young's modulus, atomic packing density and bifurcation threshold are at least partially higher than those of the comparative example, indicating that the chemically strengthened glass made from the substrate glass provided by the present application has better mechanical strength.

[0194] Referring to Table 4, Examples 6-10, Comparative Examples 9, 11, and 13 show that chemically strengthened glass prepared using the substrate glass of the present application exhibits higher CT_LD, surface CS, average sandpaper drop height, and B10 of sandpaper drop height. This demonstrates that the chemically strengthened glass in the present application examples possesses higher mechanical strength, with less dispersion in the drop height distribution of batch samples, and consistent strength performance in mass-produced chemically strengthened glass. Examples 11-16, Comparative Examples 10, 12, 14, and 15 show that Comparative Examples 10, 12, 14, and 15 cannot be mass-produced using the float glass process. For example, the chemically strengthened glass in Comparative Example 12 exhibits superior mechanical strength, but the substrate glass formulation corresponding to Comparative Example 12 has a crystallization ceiling temperature of 1248°C, far exceeding 1200°C, making it unsuitable for mass production using the float glass process. However, the substrate glass corresponding to the chemically strengthened glass in the present application examples can all be produced using the float glass process.

[0195] It is understandable that the temperature, time and type of salt bath used in the strengthening treatment of the substrate glass in the salt bath in Examples 11 to 16 are merely examples and do not impose any limitation on the technical solution of the present application. The purpose of the present application can also be achieved by using other conventional strengthening treatment temperatures, times and types of salt baths in the art.

[0196] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0197] Each embodiment in this specification is described in a related manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0198] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application are included in the scope of protection of the present application.

Claims

1. A substrate glass, wherein: Expressed in terms of molar percentage of oxides, the composition of the substrate glass comprises: SiO2 63.00~70.00mol%, Al2O3 8.00~10mol%, Li2O 9.85~10.50mol%, Y2O3 1.00~1.50mol%, Na2O 5.91~8.00mol%, MgO 2~6.00mol%, La2O3 0.10~2mol%; K2O 1.00~2.00mol%; SrO 0~3.00mol%; ZrO2 0mol%; Wherein, expressed as a molar percentage of oxides, La2O3 / Y2O3 is 0.2~0.33 or 0.4~0.6 or 0.67~1.

2. The substrate glass according to claim 1, wherein Expressed as molar percentage of oxides, Al2O3+Li2O≤20.00mol%.

3. The substrate glass according to claim 1, wherein Expressed as a molar percentage of oxides, the composition of the substrate glass includes SrO in an amount of 0 to 2.00 mol %.

4. The substrate glass according to claim 1, wherein Expressed as a molar percentage of oxides, the composition of the substrate glass includes 0.50-2.00 mol % of SrO.

5. The substrate glass according to claim 1, wherein Expressed as a molar percentage of oxides, SrO / (MgO+SrO)≤0.

35.

6. The substrate glass according to claim 5, wherein Expressed as a molar percentage of oxides, the composition of the substrate glass is: 0.05≤SrO / (MgO+SrO)≤0.

35.

7. The substrate glass according to claim 1, wherein: Expressed in molar percentage of oxides, the composition of the substrate glass includes: SiO2 64.00~69.00mol%, and / or Li2O 9.85~10.00mol%, and / or Al2O3 8.50~10mol%, and / or Na2O 5.91~6.00mol%, and / or La2O3 0.20~1.50mol%.

8. The substrate glass according to any one of claims 1 to 7, wherein The upper crystallization temperature limit of the substrate glass is less than or equal to 1185°C.

9. The substrate glass according to any one of claims 1 to 7, wherein: The upper crystallization temperature limit of the substrate glass is less than or equal to 1165°C.

10. The substrate glass according to any one of claims 1 to 7, wherein When the substrate glass of 0.7 mm thickness was ion exchanged in a 100 wt% NaNO3 salt bath at 450 ° C, the substrate glass of 1 cm thickness was 2 When 1 mg of sodium ions are introduced into the substrate glass through exchange, the stress effect QF generated is greater than or equal to 90,000 MPa / mm.

11. The substrate glass according to any one of claims 1 to 7, wherein When the substrate glass of 0.7 mm thickness was ion exchanged in a 100 wt% NaNO3 salt bath at 450 ° C, the substrate glass of 1 cm thickness was 2 When 1 mg of sodium ions is introduced into the substrate glass by exchange, the stress benefit QF generated is greater than or equal to 95,000 MPa / mm and less than or equal to 200,000 MPa / mm.

12. The substrate glass according to any one of claims 1 to 7, wherein: The maximum tensile stress linear density CT_LD obtained by ion exchange of the 0.7 mm thick substrate glass in a 100 wt% NaNO3 salt bath at 450 ° C max Greater than or equal to 50000MPa / mm.

13. The substrate glass according to any one of claims 1 to 7, wherein: The maximum tensile stress linear density CT_LD obtained by ion exchange of the 0.7 mm thick substrate glass in a 100 wt% NaNO3 salt bath at 450 ° C max It is 50000MPa / mm~90000MPa / mm.

14. The substrate glass according to claim 12, wherein The substrate glass obtains the maximum tensile stress linear density CT_LD in a 100wt% NaNO3 salt bath at 450°C. max When the depth DOL_0 of the compressive stress layer formed on the substrate glass is 0.15t~0.22t, t is the thickness of the substrate glass.

15. The substrate glass according to claim 12, wherein When the substrate glass with a thickness of 0.7 mm is placed in a 100 wt% NaNO3 salt bath at 450 °C, the maximum tensile stress linear density CT_LD is obtained. max When the amount of lithium ions released by the substrate glass into the salt bath is less than or equal to 1.00 mg / cm 2 .

16. The substrate glass according to any one of claims 1 to 7, wherein: When the ion exchange depth of the 0.7 mm thick substrate glass is 4.9-5.1 μm in a 100 wt% KNO3 salt bath at 430 °C, the CS obtained by the substrate glass is max Greater than or equal to 1000MPa.

17. The substrate glass according to any one of claims 1 to 7, wherein When the ion exchange depth of the 0.7 mm thick substrate glass is 4.9-5.1 μm in a 100 wt% KNO3 salt bath at 430 °C, the CS obtained by the substrate glass is max It is 1000MPa~1600MPa.

18. The substrate glass according to any one of claims 1 to 7, wherein: The Young's modulus of the substrate glass is greater than or equal to 85 GPa.

19. The substrate glass according to any one of claims 1 to 7, wherein: The Young's modulus of the substrate glass is greater than or equal to 90 GPa and less than or equal to 100 GPa.

20. The substrate glass according to any one of claims 1 to 7, wherein The atomic packing density of the substrate glass is greater than or equal to 0.552 and less than or equal to 0.

620.

21. The substrate glass according to any one of claims 1 to 7, wherein The bifurcation threshold of the substrate glass is greater than or equal to 40,000 MPa / mm.

22. The substrate glass according to any one of claims 1 to 7, wherein: The bifurcation threshold of the substrate glass is 40000 MPa / mm~60000 MPa / mm.

23. A chemically strengthened glass, wherein: The chemically strengthened glass is prepared by placing the substrate glass according to any one of claims 1 to 22 in a salt bath and subjecting it to ion exchange chemical strengthening; the chemically strengthened glass comprises a compressive stress layer and a tensile stress layer.

24. The chemically strengthened glass according to claim 23, wherein The composition of the tensile stress layer is the same as that of the substrate glass according to any one of claims 1 to 22.

25. A glass device, wherein: The glass device is made of the substrate glass according to any one of claims 1 to 22 or the chemically strengthened glass according to any one of claims 23 to 24.

26. An electronic device comprising the chemically strengthened glass according to claim 23 or 24.

27. The electronic device according to claim 26, wherein The electronic device includes a mobile phone, a tablet computer, a smart wearable, a display or a television.

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