Lithium aluminosilicate glass, chemically strengthened lithium aluminosilicate glass, and method for producing and using the same

Abstract

The lithium aluminosilicate glass contains, in terms of oxide molar percentages, 62-68 mol% SiO2, 9-14 mol% Al2O3, 6-10 mol% Na2O, 0.2-0.7 mol% K2O, 8.0-14.0 mol% Li2O, and 2.0-5.5 mol% MgO, with the proviso that (Li2O+Na2O+MgO) / Al2O3 is 1.7-2.5. The lithium aluminosilicate glass controls the ranges of the molar percentages of SiO2, Al2O3, Na2O, K2O, and Li2O, and the ratio of (Li2O+Na2O+MgO) / Al2O3, and ensures high strength after chemical strengthening of the obtained lithium aluminosilicate glass, meets the user's requirements for "film peeling static electricity", and further has the excellent effects of low melting temperature and energy saving.

Description

Technical Field

[0001] This disclosure claims the priority of a Chinese patent application filed with the China National Intellectual Property Administration on February 9, 2021, with an application number of 202110177598.1 and an invention title of "Lithium Aluminosilicate Glass, Chemically Strengthened Lithium Aluminosilicate Glass, and Manufacturing Method and Use Thereof", and all its contents are incorporated herein by reference. The present invention relates to the field of glass technology, and specifically to lithium aluminosilicate glass, chemically strengthened lithium aluminosilicate glass, and manufacturing methods and uses thereof.

Background Art

[0002] Lithium aluminosilicate glass can be chemically strengthened twice, that is, first, Li on the glass surface is exchanged with Na, and then Na on the glass surface is exchanged with K. Since large ions can replace small ions twice, a greater compressive stress can be applied to the glass surface, better sealing the "Griffith cracks" on the surface, and improving the strength of the glass by nearly 20 times. As a result, it is used as a protective glass (also called cover glass, Cover Glass) for the screen of touch smart display terminals. + on the glass surface, and then + is exchanged with + on the glass surface, and then + is exchanged with K. Since large ions can replace small ions twice, a greater compressive stress can be applied to the glass surface, better sealing the "Griffith cracks" on the surface, and improving the strength of the glass by nearly 20 times. As a result, it is used as a protective glass (also called cover glass, Cover Glass) for the screen of touch smart display terminals.

[0003] Also, lithium aluminosilicate glass requires a high Young's modulus and corrosion resistance to avoid scratches and cloudiness during the processing process before strengthening. Therefore, conventional products often introduce oxides such as high silicon oxide, aluminum oxide, and zirconium oxide to address this problem. However, when these oxides are introduced excessively, the melting temperature of the glass increases, the mass production methods and conditions become severe, and the energy consumption is high.

Summary of the Invention

Problems to be Solved by the Invention

[0004] One of the objectives of the embodiments of the present disclosure is to provide a lithium aluminosilicate glass, a chemically strengthened lithium aluminosilicate glass, and a manufacturing method and use thereof, so as to solve the problems that the strength of the lithium aluminosilicate glass in the prior art is low, the film peeling static electricity is high, and the energy consumption is high.

Means for Solving the Problems

[0005] In order to solve the above problems, the embodiments of the present disclosure adopt the following means.

[0006] The first aspect provides a lithium aluminosilicate glass, The lithium aluminosilicate glass has, in terms of molar percentage of oxides, 62 to 68 mol% of SiO2, 9 to 14 mol% of Al2O3, 6 to 10 mol% of Na2O, 0.2 to 0.7 mol% of K2O, 8.0 to 14.0 mol% of Li2O, 2.0 to 5.5 mol% of MgO, and wherein (Li2O + Na2O + MgO) / Al2O3 is 1.7 to 2.5.

[0007] In addition, the lithium aluminosilicate glass further contains 0.5 to 1.5 mol% of ZrO2 in terms of molar percentage of oxides.

[0008] In addition, the thickness of the lithium aluminosilicate glass is 0.25 mm to 2.5 mm.

[0009] In addition, the molar percentage of Li2O is 8.0 to 13.0 mol%.

[0010] In addition, the molar percentage of SiO2 is 63 to 67 mol%.

[0011] Further, when the stress layer depth (DOL) of the lithium aluminosilicate glass is 30 μm, the compressive stress (CS-30) is greater than 100 MPa.

[0012] Further, when the lithium aluminosilicate glass is dropped onto 180-mesh silicon carbide abrasive paper with a load of 180 g so that the surface lands at the free fall speed, the fracture height reaches 1.6 meters or more.

[0013] Further, the melting temperature of the lithium aluminosilicate glass is lower than 1590 °C.

[0014] A second aspect provides a method for manufacturing a lithium aluminosilicate glass, and the method for manufacturing the lithium aluminosilicate glass includes the steps of mixing, melting, shaping, and annealing the raw materials of the components of the lithium aluminosilicate glass in proportion to produce the lithium aluminosilicate glass.

[0015] Further, the melting temperature is 1510 °C to 1578 °C.

[0016] A third aspect provides a lithium aluminosilicate chemically strengthened glass, wherein the lithium aluminosilicate chemically strengthened glass is formed through chemical strengthening treatment from the lithium aluminosilicate glass or the lithium aluminosilicate glass produced by the method for manufacturing the lithium aluminosilicate glass.

[0017] Further, when the stress layer depth (DOL) of the lithium aluminosilicate chemically strengthened glass is 30 μm, the compressive stress value (CS-30) is greater than 100 MPa.

[0018] Further, the melting temperature of the lithium aluminosilicate chemically strengthened glass at a viscosity of 10 2 dPa·s is less than 1590 °C.

[0019] Further, when the lithium aluminosilicate chemically strengthened glass is coated with a protective film, the "film peeling static electricity" generated at the moment of peeling the protective film after bonding to the module is less than 300V.

[0020] The fourth aspect provides a method for manufacturing a lithium aluminosilicate chemically strengthened glass, including the step of strengthening the lithium aluminosilicate glass in a monovalent metal nitrate molten salt to obtain the lithium aluminosilicate chemically strengthened glass.

[0021] Further, the monovalent metal nitrate molten salt is sequentially selected from a sodium nitrate molten salt and a potassium nitrate molten salt, or the monovalent metal nitrate molten salt is selected from a mixed molten salt of sodium nitrate and potassium nitrate, In the step of the strengthening treatment, the period of the strengthening treatment is 1 to 3 hours, and the temperature of the strengthening treatment is 380 to 450 °C.

[0022] Further, when the monovalent metal nitrate molten salt is sequentially selected from a sodium nitrate molten salt and a potassium nitrate molten salt, first, the lithium aluminosilicate glass is subjected to a first strengthening treatment in a pure sodium nitrate molten salt, and then a second strengthening treatment is performed in a pure potassium nitrate molten salt.

[0023] Further, when the thickness of the lithium aluminosilicate glass is 0.70 mm, first, it is immersed in a pure sodium nitrate molten salt at 440 °C for 2 hours to perform the first chemical strengthening, and then it is immersed in a pure potassium nitrate molten salt at 420 °C for 1.5 hours to perform the second chemical strengthening.

[0024] The fifth aspect provides the use of the lithium aluminosilicate chemically strengthened glass or the lithium aluminosilicate chemically strengthened glass obtained by the method for manufacturing the lithium aluminosilicate chemically strengthened glass in a display screen protection glass.

Advantages of the Invention

[0025] Compared with the prior art, the present disclosure has the following technical effects.

[0026] According to the lithium aluminosilicate glass according to the present disclosure, by controlling the molar percentages of SiO2, Al2O3, Na2O, K2O, Li2O and the ratio of (Li2O + Na2O + MgO) / Al2O3, the resulting lithium aluminosilicate glass can ensure high strength after chemical strengthening, meet the user requirements for "film peeling static electricity", and further has the excellent effects of low melting temperature and energy saving.

[0027] According to the manufacturing method of the lithium aluminosilicate glass according to the present disclosure, it is simple and convenient. By the process of mixing, melting, forming, and annealing each component, lithium aluminosilicate glass can be obtained. The operation is simple and suitable for large-scale industrial applications.

[0028] According to the lithium aluminosilicate chemically strengthened glass according to the present disclosure, it is formed through a chemical strengthening treatment from the lithium aluminosilicate glass. When the depth of the stress layer (DOL) of the obtained lithium aluminosilicate chemically strengthened glass is 30 μm, the compressive stress value (CS-30) is greater than 100 MPa. The melting temperature at a glass viscosity of 10 2 dPa·s is less than 1590°C. TP (lithium aluminosilicate chemically strengthened glass), when the protective film is coated, after being bonded to the LCM (LCD liquid crystal display module), the "film peeling static electricity" generated at the moment of peeling off the protective film is less than 300V. The obtained lithium aluminosilicate chemically strengthened glass has excellent properties of high strength, low "film peeling static electricity", low melting temperature, and energy saving.

[0029] According to the manufacturing method of the lithium aluminosilicate chemically strengthened glass according to the present disclosure, the lithium aluminosilicate glass may be strengthened in a monovalent metal nitrate molten salt. The process is simple and advantageous for wide applications.

[0030] According to the use of the lithium aluminosilicate chemically strengthened glass in the display screen protection glass according to the present disclosure, the lithium aluminosilicate chemically strengthened glass has excellent properties of high strength, low "film peeling static electricity", low melting temperature, and energy saving. Therefore, the obtained application products also have excellent merits of high strength and low "film peeling static electricity".

[0031] To more clearly explain the technical solutions in the embodiments of the present disclosure, the drawings that need to be used in the following examples or exemplary technical descriptions will be briefly introduced. Needless to say, the drawings in the following descriptions are only some embodiments of the present disclosure. For those skilled in the art, other drawings can also be obtained based on these drawings without creative efforts.

Brief Description of the Drawings

[0032]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0033] To make the technical problems, technical solutions and technical effects to be solved by the present disclosure clearer, the present disclosure will be described in more detail below in connection with the embodiments. The specific embodiments described here are only for explaining the present disclosure and do not limit the present disclosure. It should be understood by those skilled in the art that all other embodiments obtained based on the embodiments in the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0034] To explain the technical solutions according to the present disclosure, the following will be described in detail in connection with specific drawings and embodiments.

[0035] The first aspect of the embodiment of the present disclosure provides a lithium aluminosilicate glass, Lithium aluminosilicate glass, in terms of molar percentage of oxides, contains 62 - 68 mol% of SiO2, 9 - 14 mol% of Al2O3, 6 - 10 mol% of Na2O, 0.2 - 0.7 mol% of K2O, 8.0 - 14.0 mol% of Li2O, 2.0 - 5.5 mol% of MgO, provided that (Li2O + Na2O + MgO) / Al2O3 is 1.7 - 2.5.

[0036] The lithium aluminosilicate glass according to the first aspect of the embodiments of the present disclosure controls the ranges of the molar percentages of SiO2, Al2O3, Na2O, K2O, Li2O and the ratio of (Li2O + Na2O + MgO) / Al2O3, ensuring high strength after the obtained lithium aluminosilicate glass is chemically strengthened, meeting the user's requirements for "film peeling static electricity", and further having the excellent effects of low melting temperature and energy saving.

[0037] Specifically, the lithium aluminosilicate glass contains 62 - 68 mol% of SiO2 in terms of molar percentage of oxides. Here, SiO2 is the main component of the lithium aluminosilicate glass. By adding SiO2, sufficient Young's modulus and corrosion resistance can be imparted to the glass, thereby meeting the user's requirements of being difficult to be damaged and not cloudy during processing.

[0038] Here, the molar percentage of SiO2 is 62 - 68 mol%. If the addition amount of SiO2 is less than 62 mol%, the corrosion resistance of the obtained lithium aluminosilicate glass will deteriorate. If the addition amount of SiO2 exceeds 68 mol%, the melting temperature of the obtained lithium aluminosilicate glass will increase, making mass production difficult, increasing energy consumption, and being disadvantageous for large-scale production.

[0039] In some embodiments, the lithium aluminosilicate glass has a molar percentage of SiO2 of 63 to 67 mol%. In specific embodiments, the molar percentage of SiO2 in the lithium aluminosilicate glass is selected from 62 mol%, 62.5 mol%, 63 mol%, 63.5 mol%, 64 mol%, 64.5 mol%, 65 mol%, 65.5 mol%, 66 mol%, 66.5 mol%, 67 mol%, 67.5 mol%, 68 mol%.

[0040] Specifically, the lithium aluminosilicate glass contains 9 to 14 mol% of Al2O3 in terms of molar percentage of oxides. Here, Al2O3 is preferably compounded with SiO2, which can not only improve the corrosion resistance of the glass, but also promote the progress of strengthening by increasing the alkali metal ion channels during chemical strengthening, and a larger compressive stress and stress layer depth can be obtained.

[0041] Here, the molar percentage of Al2O3 is 9 to 14 mol%. When the addition amount of Al2O3 is less than 9 mol%, the corrosion resistance and strength of the obtained lithium aluminosilicate glass are not ideal. When the addition amount of Al2O3 exceeds 14 mol%, the melting temperature of the obtained lithium aluminosilicate glass becomes high, mass production becomes difficult, energy consumption increases, which is disadvantageous for mass production.

[0042] In some embodiments, the lithium aluminosilicate glass has a molar percentage of Al2O3 of 9 to 14 mol%. In specific embodiments, the molar percentage of Al2O3 in the lithium aluminosilicate glass is selected from 9 mol%, 9.5 mol%, 10 mol%, 10.5 mol%, 11 mol%, 11.5 mol%, 12 mol%, 12.5 mol%, 13 mol%, 13.5 mol%, 14 mol%.

[0043] Specifically, the lithium aluminosilicate glass contains 6 to 10 mol% of Na2O in terms of molar percentage of oxides. Here, the addition of Na2O can significantly improve the strength when the glass is chemically strengthened, and it also contributes to melting and reduces the viscosity, that is, the melting temperature is lowered, and accordingly the forming and annealing temperatures are lowered, achieving the purpose of energy conservation. In addition, Na2O is an essential substance for ion exchange in the process of strengthening treatment, and provides Na2O to ensure that the subsequent strengthening treatment is carried out smoothly.

[0044] Here, the molar percentage of Na2O is 6 to 10 mol%. When the addition amount of Na2O is less than 6 mol%, the compressive stress due to ion exchange of the obtained lithium aluminosilicate glass is low, and the corresponding CS-30 does not reach 100 MPa, the sealing against "Griffith cracks" is not ideal, and glass cracking due to crack propagation still occurs. When the addition amount of Na2O exceeds 10 mol%, the chemical stability and Young's modulus of the obtained lithium aluminosilicate glass decrease, and cloudiness and scratches are likely to occur during the processing process of users, which is disadvantageous for use.

[0045] In some embodiments, the lithium aluminosilicate glass has a molar percentage of Na2O of 6 to 10 mol%. In specific embodiments, the molar percentage of Na2O in the lithium aluminosilicate glass is selected from 6 mol%, 6.5 mol%, 7 mol%, 7.5 mol%, 8 mol%, 8.5 mol%, 9 mol%, 9.5 mol%, 10 mol%.

[0046] Specifically, the lithium aluminosilicate glass contains 0.2 to 0.7 mol% of K2O in terms of the molar percentage of oxides. Here, the addition of K2O can significantly improve the strength when the glass is chemically strengthened, and it also contributes to melting and reduces the viscosity, that is, the melting temperature decreases, and accordingly the forming and annealing temperatures decrease, achieving the purpose of energy saving. In addition, K2O is an essential substance for ion exchange in the process of strengthening treatment. Potassium ions can accelerate the ions in the strengthening process, shorten the ion exchange time, and improve the strengthening efficiency.

[0047] Here, the molar percentage of K2O is 0.2 to 0.7 mol%. As shown in Figure 1, by controlling the molar percentage of K2O to be greater than 0.2 mol% and less than 0.7 mol%, the strengthening process can be accelerated, the ion exchange time can be shortened, and the strengthening efficiency can be improved. Also, when the user works in a place with a certain level of cleanliness, since the "film peeling static electricity" is greater than 500 V, dust adsorption can be avoided, preventing the product from being discarded. If the addition amount of K2O is less than 0.2 mol%, the ion exchange time in the strengthening process of the obtained lithium aluminosilicate glass will be prolonged, and the strengthening efficiency will be low. If the addition amount of K2O exceeds 0.7 mol%, since both potassium oxide and sodium oxide are present, the "mixed alkali effect" is realized, the surface resistance of the glass is improved. When applied to the user, after chemically strengthening the glass product and plating an AF film (anti-fingerprint film), when pasted to an LCM (LCD liquid crystal display module), the "film peeling static electricity" generated at the moment of peeling off the outermost protective film of the product will be greater than 500 V, excessive dust particles will be adsorbed, and the product will be discarded, which is disadvantageous for use.

[0048] In some embodiments, the lithium aluminosilicate glass has a molar percentage of K2O of 0.2 to 0.7 mol%. In the lithium aluminosilicate glass in specific embodiments, the molar percentage of K2O is selected from 0.2 mol%, 0.25 mol%, 0.3 mol%, 0.35 mol%, 0.4 mol%, 0.45 mol%, 0.5 mol%, 0.55 mol%, 0.6 mol%, 0.65 mol%, 0.7 mol%.

[0049] Specifically, the lithium aluminosilicate glass contains 8.0 to 14.0 mol% of Li2O in terms of the molar percentage of oxides. Here, the addition of Li2O not only greatly improves the strength when the glass is chemically strengthened, but also contributes to melting and reduces the viscosity, that is, the melting temperature decreases, and accordingly the forming and annealing temperatures decrease, achieving the purpose of energy saving. Also, Li2O is an essential substance for ion exchange in the process of performing the strengthening treatment, and is provided to ensure that the subsequent strengthening treatment is carried out smoothly.

[0050] Here, the molar percentage of Li2O is 8.0 to 14.0 mol%. If the addition amount of Li2O is less than 8.0 mol%, the depth of the compressive stress layer reached by ion exchange is too low, the sealing against "Griffith cracks" is not ideal, and the possibility of glass cracking and failure due to crack propagation is still high. If the addition amount of Li2O exceeds 14.0 mol%, the crystallization tendency of the glass increases, crystallization occurs in the process and defects are generated, and ultimately devitrification occurs.

[0051] In some embodiments, in the lithium aluminosilicate glass, the molar percentage of Li2O is 8.0 to 13.0 mol%. Further, in the lithium aluminosilicate glass, the molar percentage of Li2O is 8.0 to 12.0 mol%.

[0052] In a specific embodiment, in the lithium aluminosilicate glass, the molar percentage of Li2O is selected from 8 mol%, 8.5 mol%, 9 mol%, 9.5 mol%, 10 mol%, 10.5 mol%, 11 mol%, 11.5 mol%, and 12 mol%.

[0053] Specifically, in the lithium aluminosilicate glass, (Li2O + Na2O + MgO) / Al2O3 is 1.7 to 2.5. By controlling the ratio of (Li2O + Na2O + MgO) / Al2O3, the obtained lithium aluminosilicate glass, after being strengthened, has a compressive stress CS-30 corresponding to a depth of layer of stress DOL of 30 μm greater than 100 MPa. Such strength can well achieve the sealing against "Griffith cracks". Using a simulated mobile phone, with a load of 180 g and dropping it onto 180-mesh silicon carbide abrasive paper so that the surface lands at the free-fall speed, its fracture height reaches 1.6 meters or more. Also, the melting temperature of the glass is less than 1590 °C, and accordingly, the forming and annealing temperatures are also low, mass production is easy, and it is energy-saving. The obtained lithium aluminosilicate glass achieves the purpose of being scratch-resistant before chemical strengthening and corrosion-resistant after strengthening, and obtains the advantages of low melting temperature, high ion exchange rate, and high strength.

[0054] In some embodiments, some lithium aluminosilicate glasses are added with alkaline earth metal oxides, which contribute to the reduction of the melting temperature, adjust the glass forming material performance, are advantageous for controlling the forming temperature after addition, and have the effect of suppressing crystallization. However, Ca + , Sr + , Ba + have large ionic radii, which are 1.00 Å, 1.18 Å, and 1.35 Å respectively, so the glass structure lattice becomes "stagnant", inhibits the passage through the ion exchange path, and reduces the ion exchange efficiency. Therefore, the lithium aluminosilicate glass according to the present disclosure has Ca + , Sr + , Ba +Use a material into which magnesium oxide raw material with a small ionic radius is introduced without using a material into which ions are introduced.

[0055] Furthermore, the lithium aluminosilicate glass contains 2.0 - 5.5 mol% of MgO in terms of the molar percentage of oxides. The introduction of MgO contributes to the decrease in the melting temperature, adjusts the performance of the glass forming material, is advantageous for controlling the forming temperature after addition, and plays a role in suppressing crystallization. Also, in magnesium oxide ions, the ionic radius of magnesium is relatively small at 0.72 Å, which can reduce the melting and fusion, suppress crystallization, adjust the performance of the forming material, and provide a smoother ion exchange path.

[0056] In some embodiments, the lithium aluminosilicate glass has a MgO molar percentage of 2.0 - 5.5 mol%. In specific embodiments, in the lithium aluminosilicate glass, the molar percentage of MgO is selected from 2 mol%, 2.5 mol%, 3 mol%, 3.5 mol%, 4 mol%, 4.5 mol%, 5 mol%.

[0057] Furthermore, the lithium aluminosilicate glass contains 0.5 - 1.5 mol% of ZrO2 in terms of the molar percentage of oxides. The introduction of ZrO2 is advantageous for improving the inherent strength of the glass, that is, improving the elastic modulus, and increasing the scratch resistance and corrosion resistance during user processing before chemical strengthening. If the addition amount of ZrO2 is too high, it will increase the glass viscosity, increase the melting difficulty, and increase the energy consumption.

[0058] In some embodiments, the molar percentage of ZrO2 in the lithium aluminosilicate glass is 0.5 - 1.5 mol%. In specific embodiments, the molar percentage of ZrO2 in the lithium aluminosilicate glass is selected from 0.5 mol%, 1 mol%, 1.5 mol%.

[0059] Furthermore, the thickness of the lithium aluminosilicate glass is 0.25 mm - 2.5 mm.

[0060] The second aspect of the embodiments of the present disclosure provides a method for manufacturing lithium aluminosilicate glass, S01 determining the components of lithium aluminosilicate glass; S02 mixing, melting, forming, and annealing the raw materials of the components of lithium aluminosilicate glass in proportion to produce lithium aluminosilicate glass.

[0061] The method for manufacturing lithium aluminosilicate glass according to the second aspect of the embodiments of the present disclosure is a process of sequentially performing mixing, melting, forming, and annealing according to the raw materials of each component of lithium aluminosilicate glass. The obtained lithium aluminosilicate glass has high strength after strengthening, meets the user requirements for "film peeling electrostatic", has a low melting temperature, and has the excellent effect of reducing energy consumption. In addition, the manufacturing method is simple and convenient, easy to operate, and suitable for large-scale industrial applications.

[0062] In step S01, based on the above-mentioned lithium aluminosilicate glass, the content of each component is provided to determine the mixing ratio of the raw materials, which will not be described here.

[0063] In step S02, the raw materials of the components are mixed, melted, formed, and annealed in proportion to produce lithium aluminosilicate glass. Here, the melting temperature is 1510 °C to 1578 °C. The melting treatment is performed at this temperature. Further, it includes good product detection, cutting, sorting, stacking, extraction, and warehousing.

[0064] The lithium aluminosilicate chemically strengthened glass according to the third aspect of the present disclosure is formed through chemical strengthening treatment from lithium aluminosilicate glass or lithium aluminosilicate glass manufactured by the method for manufacturing lithium aluminosilicate glass.

[0065] The lithium aluminosilicate chemically strengthened glass according to the third aspect of the present disclosure is formed through chemical strengthening treatment from lithium aluminosilicate glass. The obtained lithium aluminosilicate chemically strengthened glass has a compressive stress value CS-30 greater than 100 MPa when the depth of the stress layer (DOL) is 30 μm. The melting temperature when the glass viscosity is 10 2 dPa·s is less than 1590°C. When the lithium aluminosilicate chemically strengthened glass is coated with a protective film, the "film peeling static electricity" generated at the moment of peeling off the protective film after laminating to a module is less than 300 V. The obtained lithium aluminosilicate chemically strengthened glass has excellent properties of high strength, low "film peeling static electricity", low melting temperature, and energy saving.

[0066] The manufacturing method of the lithium aluminosilicate chemically strengthened glass according to the fourth aspect of the present disclosure is G01 including the step of strengthening lithium aluminosilicate glass in a monovalent metal nitrate molten salt to obtain lithium aluminosilicate chemically strengthened glass.

[0067] The manufacturing method of the lithium aluminosilicate chemically strengthened glass according to the fourth aspect of the present disclosure strengthens lithium aluminosilicate glass in a monovalent metal nitrate molten salt to obtain lithium aluminosilicate chemically strengthened glass. The compressive stress value CS-30 of the lithium aluminosilicate chemically strengthened glass when the depth of the stress layer (DOL) is 30 μm is greater than 100 MPa. The melting temperature at a glass viscosity of 10 2 dPa·s is less than 1590°C. TP (lithium aluminosilicate chemically strengthened glass) has a "film peeling static electricity" less than 300 V generated at the moment of peeling off the protective film after laminating to an LCM (LCD liquid crystal display module) when there is a protective film. Therefore, the obtained lithium aluminosilicate chemically strengthened glass has excellent properties of high strength, low "film peeling static electricity", low melting temperature, and energy saving. Also, the manufacturing method has a simple process and is advantageous for wide applications.

[0068] In step G01, the monovalent metal nitrate molten salt is sequentially selected from sodium nitrate molten salt and potassium nitrate molten salt. Alternatively, the monovalent metal nitrate molten salt is selected from a mixed molten salt of sodium nitrate and potassium nitrate.

[0069] In some embodiments, when the monovalent metal nitrate molten salt is sequentially selected from sodium nitrate molten salt and potassium nitrate molten salt, the lithium aluminosilicate glass is subjected to a first strengthening treatment in pure sodium nitrate molten salt, and then a second strengthening treatment in pure potassium nitrate molten salt.

[0070] In some other embodiments, the lithium aluminosilicate glass is subjected to two strengthening treatments in sodium nitrate and a mixed molten salt of sodium nitrate and potassium nitrate.

[0071] Here, in the strengthening treatment step, the strengthening treatment time is 1 to 3 hours, and the strengthening treatment temperature is 380 to 450 °C.

[0072] In a specific embodiment, taking a 0.70 mm glass plate as an example, it is immersed in pure sodium nitrate molten salt at 440 °C for 2 hours for the first chemical strengthening, and then immersed in pure potassium nitrate molten salt at 420 °C for 1.5 hours for the second chemical strengthening.

[0073] The fifth aspect of the embodiments of the present disclosure provides the use of lithium aluminosilicate chemically strengthened glass or lithium aluminosilicate chemically strengthened glass produced by a method for producing lithium aluminosilicate chemically strengthened glass in a display screen protection glass.

[0074] Furthermore, the lithium aluminosilicate chemically strengthened glass is used for protecting the display screen of electronic products, automotive windows, automotive cover glasses, etc., but is not limited thereto.

[0075] According to the use of lithium aluminosilicate chemically strengthened glass in the screen protection glass according to the fifth aspect of the embodiments of the present disclosure, the lithium aluminosilicate chemically strengthened glass has excellent properties such as high strength, low "film peeling static electricity", low melting temperature, and energy saving. Therefore, the obtained product also has excellent merits of high strength and low "film peeling static electricity".

[0076] Hereinafter, it will be described in relation to specific examples.

[0077] <Examples and Comparative Examples> For the sake of brief explanation, the components of the lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 1. Based on the glass components shown in Table 1, they were prepared as follows.

[0078] Based on the lithium aluminosilicate glass components, the required raw materials were calculated, and the raw materials were uniformly mixed and prepared into a 0.70 mm glass plate by the float method, the overflow method or the crucible melting method. Then, the glass plate was cut and quality inspected to obtain lithium aluminosilicate glass.

[0079] The obtained lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3 were immersed in pure sodium nitrate molten salt at 440 °C for 2 hours for the first chemical strengthening, and then immersed in pure potassium nitrate molten salt at 420 °C for 1.5 hours for the second chemical strengthening treatment, respectively obtaining the lithium aluminosilicate chemically strengthened glasses of Examples 1 to 5 and Comparative Examples 1 to 3.

[0080]

Table 1

[0081] <Performance Test> For the lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3 and the lithium aluminosilicate chemically strengthened glasses of Examples 1 to 5 and Comparative Examples 1 to 3, the following performance tests were conducted.

[0082] (1) For the lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3, in accordance with the ASTM C965 glass viscosity measurement method, the melting temperature, that is, the temperature at which the viscosity value is 10 2 dPa·s was detected.

[0083] (2) For the chemically strengthened lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3, CS-30 was detected using an SLP-200 scattered light photoelastic stress meter manufactured by Nippon Orijin Co., Ltd.

[0084] (3) For the chemically strengthened lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3, the overall drop height was detected. The detection method was to use a drop tester (model number HE-DL-315D) manufactured by Dongguan Haowen Automation Equipment Co., Ltd., cover the ground with 180-mesh silicon carbide abrasive paper, use a simulated mobile phone model with a weight of 180 g, face down, at a free fall speed, starting from 90 cm, and increase the height by 5 cm each time until the glass cracks (until cracks occur) and drop.

[0085] (4) For the chemically strengthened lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3, after depositing an AF film on one side, the uncoated side was bonded to an LCM (LCD liquid crystal display module) using an OCA adhesive. Such a glass plate is called a cover glass coated module. A protective film was coated on the cover glass of the module, and "film peeling static electricity" was detected. The detection method was to use a film peeling static electricity measuring device (model number TREK-520 (USA)), with a measurement range of 0 to ±1999 V, a test environment requirement humidity of 40% to 60%, and a temperature of 18 to 28°C. Ensure that the probe of the film peeling static electricity measuring device is perpendicular to the surface of the sample to be measured. The tester wears an anti-static glove and an anti-static ring. The test probe is 5 to 15 mm away from the glass surface, the film peeling speed is 0.5 s, and the sample is suspended in the air without being placed on the table, and the voltage value of the static electricity at the moment of film peeling is detected.

[0086] <Result Analysis> Table 2 shows the results of performance tests on the lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3 and the chemically strengthened lithium aluminosilicate glasses of Examples 1 to 5 and Comparative Examples 1 to 3. The lithium aluminosilicate glasses obtained in Examples 1 to 5 had a melting temperature of 1590°C or lower, and the obtained chemically strengthened lithium aluminosilicate glasses had a CS-30 greater than 100 MPa, a film peeling charge (V) less than 300 V, and a drop height (load 180 g, 180-mesh silicon carbide abrasive paper) greater than 160 cm. Therefore, the lithium aluminosilicate glasses obtained in Examples 1 to 5 have high strength after chemical strengthening, meet the user requirements for "film peeling static electricity", have a low melting temperature, and have excellent effects of energy saving.

[0087] On the other hand, in the lithium aluminosilicate glasses of Comparative Examples 1 to 3, in Comparative Example 1, the "film peeling static electricity" was less than 300 V, but none of the other items achieved the expected effects of the present invention. In Comparative Examples 2 to 3, the melting temperature was greater than 1610°C, the CS-30 was less than 95 MPa, the film peeling static electricity (V) was greater than 300 V, and the drop height (load 180 g, 180-mesh silicon carbide abrasive paper) was less than 90 cm, and none of them achieved the expected effects of the present invention. The expected effects are a melting temperature <1590°C, a CS-30 >100 MPa, a film peeling static electricity (V) <300 V, and a drop height (load 180 g, 180-mesh silicon carbide abrasive paper) >160 cm.

[0088]

Table 2

[0089] Here, as shown in FIG. 2, the lithium aluminosilicate glass obtained in Examples 1 to 5 has a compressive stress CS-30 greater than 100 MPa when the depth of the stress layer DOL after strengthening treatment is 30 μm. Such strength can satisfactorily seal against "Griffith cracks". When a simulated mobile phone is used and dropped onto 180-mesh silicon carbide abrasive paper with a load of 180 g so that the surface lands at the free-fall speed, the fracture height reaches 1.6 meters or more.

[0090] As described above, the lithium aluminosilicate glass according to the present disclosure controls the molar percentages of SiO 2、 Al2O3, Na2O, K2O, Li2O and the ratio of (Li2O + Na2O + MgO) / Al2O3. The obtained lithium aluminosilicate glass has high strength after chemical strengthening, meets the user requirements for "film peeling static electricity", has a low melting temperature, and has the excellent effect of being energy-saving.

[0091] The above content is only an example of the present disclosure and does not limit the present disclosure. For those skilled in the art, various changes and modifications can be made based on the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present disclosure should all be included within the scope of the claims of the present disclosure.

Claims

1. In terms of the molar percentage of the oxide, 62 to 68 mol% of SiO ２ , 9 to 14 mol% of Al ２ O ３ , 6 to 10 mol% of Na ２ O, 0.2 to 0.7 mol% of K ２ O, 8.0 to 14.0 mol% of Li ２ O, 2.0 to 5.5 mol% of MgO, 0.5 to 1.5 mol% of ZrO ２ , and containing (Li ２ O + Na ２ O + MgO) / Al ２ O ３ is a lithium aluminosilicate glass with a value of 1.7 to 2.5, When the lithium aluminosilicate glass has a depth of the stress layer (DOL) of 30 μm, the compressive stress (CS-30) is greater than 100 MPa, and / or When the lithium aluminosilicate glass is dropped onto 180-mesh silicon carbide abrasive paper with a load of 180 g so that the surface lands at the free-fall speed, the fracture height reaches 1.6 meters or more. Lithium aluminosilicate glass.

2. The thickness of the lithium aluminosilicate glass is 0.25 mm to 2.5 mm, The lithium aluminosilicate glass according to Claim 1.

3. The Li ２ mole percentage of O is 8.0 to 13.0 mol%, and / or The molar percentage of the SiO ２ is 63 to 67 mol%, The lithium aluminosilicate glass according to Claim 1.

4. The lithium aluminosilicate glass has a melting temperature at a viscosity of 10 ２ dPa·s that is lower than 1590 °C. The lithium aluminosilicate glass according to Claim 1.

5. A step of manufacturing a lithium aluminosilicate glass by mixing, melting, forming, and annealing the raw materials of the components of the lithium aluminosilicate glass according to any one of Claims 1 to 4 in proportion is included. A method for manufacturing a lithium aluminosilicate glass.

6. In the melting, the temperature for performing the melting treatment is 1510 °C to 1578 °C. The method for manufacturing a lithium aluminosilicate glass according to Claim 5.

7. Use of the lithium aluminosilicate glass according to Claim 1 in a display screen protection glass.

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