A method for preparing ultra-thin aluminosilicate glass

Abstract

The present invention relates to the technical field of special glass manufacturing, and particularly to a method for preparing ultra-thin aluminosilicate glass. SiO₂, Al₂O₃, MgO, K₂O, Na₂O, ZrO₂ / Li₂O are mixed in proportion; the mixed raw materials are fed into a glass melting furnace for high-temperature melting to form molten glass liquid; the molten glass liquid is poured into a float bath filled with tin liquid to form a uniform glass ribbon on the surface of the tin liquid; the glass ribbon in the tin bath is left standing and cooled until solidified to form flat glass; the solidified flat glass is annealed and chemically strengthened during the annealing process; it is determined whether the chemical strengthening treatment meets the preset standard according to the strengthening warpage value; it is determined secondly whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value; the flat glass with the chemical strengthening treatment meeting the preset standard is cut to obtain ultra-thin aluminosilicate glass, improving the quality of the ultra-thin aluminosilicate glass.

Description

Technical Field

[0001] The present invention relates to the technical field of special glass manufacturing, and particularly to a method for preparing ultra-thin aluminosilicate glass. Background Art

[0002] Ultra-thin glass, also known as ultra-thin electronic touch-control glass, has a thickness between 0.1 - 1.1 mm. Ultra-thin glass has excellent hardness, transparency, heat resistance, electrical insulation, airtightness, and relatively stable mechanical and chemical properties in an oxidation and light environment. It can be applied to displays such as tablet computers, mobile phones, wearable devices, in-vehicle displays, such as wrist watches, 2.5D, 3D mobile phones, foldable mobile phones, flexible e-books, curved TVs, etc.

[0003] Ultra-thin glass is mainly divided into substrate glass, cover glass, and touch-control glass according to its use and function. Among them, the cover glass is mainly used to protect the functional components inside the display device and needs to have good mechanical strength (flexural resistance, impact resistance, and drop resistance). To achieve the required mechanical properties, during the processing of the cover glass, the glass often needs to be chemically strengthened. Currently, the main production processes for cover glass substrates are the overflow method and the float method. Compared with the overflow method, the float production process has the advantages of good flatness of the original sheet and large production capacity. However, since the glass substrate produced by the float method has a tin side and a non-tin side, after chemical strengthening, the glass has a large strengthening warpage, which affects the fitting. Moreover, as the size of current client products is getting larger and the warpage value requirement is getting smaller, the problem of large warpage of the float electronic glass substrate after chemical strengthening needs to be urgently improved.

[0004] Chinese Patent Application Publication No.: CN105837031B discloses a high-strength chemically strengthened glass. At least one side of the high-strength chemically strengthened glass contains an ion exchange layer, and the ion exchange layer contains divalent alkaline earth metal ions that enter the interior of the high-strength chemically strengthened glass through an ion exchange chemical strengthening process; the ion exchange layer also contains monovalent alkali metal ions that enter the interior of the high-strength chemically strengthened glass through an ion exchange chemical strengthening process. The present invention also provides a method for strengthening a glass substrate, including the following steps: placing the glass substrate to be strengthened in an ion exchange salt bath for ion exchange strengthening to obtain the high-strength chemically strengthened glass. It can be seen that the above technical solution does not consider the problem that chemical strengthening will cause warpage of the glass and affect the glass performance. Summary of the Invention

[0005] Therefore, the present invention provides a method for preparing ultra-thin aluminosilicate glass to overcome the problem of large warpage of the float electronic glass substrate after chemical strengthening in the prior art.

[0006] To achieve the above object, the present invention provides a method for preparing ultra-thin aluminosilicate glass, including

[0007] Step S1, mix SiO2, Al2O3, MgO, K2O, Na2O and ZrO2 / Li2O in proportion;

[0008] Step S2, feed the mixed raw materials into a glass melting furnace for high-temperature melting to form molten glass;

[0009] Step S3, pour the molten glass into a float bath filled with tin liquid to form a uniform glass ribbon on the surface of the tin liquid;

[0010] Step S4, let the glass ribbon in the tin bath stand still and cool until it solidifies to form flat glass;

[0011] Step S5, anneal the solidified flat glass and perform chemical strengthening treatment during the annealing process;

[0012] Step S6, when it is determined that the chemical strengthening treatment does not meet the preset standard according to the strengthening warpage value, re-determine whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value;

[0013] Step S7, when it is re-determined that the chemical strengthening treatment does not meet the preset standard according to the strength evaluation value, increase the temperature of the spraying area according to the difference between the strength evaluation value and the first preset strength evaluation value, or reduce the sodium / lithium content in the molten salt according to the difference between the strength evaluation value and the second preset strength evaluation value;

[0014] Step S8, cut the flat glass that meets the preset standard after chemical strengthening treatment to obtain ultra-thin aluminosilicate glass.

[0015] Further, the chemical strengthening process includes:

[0016] Step S501, preheat the glass to a temperature close to the melting point of the molten salt;

[0017] Step S502, spray a layer of molten salt on the non-tin surface of the glass for ion exchange;

[0018] Step S503, keep the glass at the glass annealing point for a preset duration;

[0019] Step S504, cool the glass to room temperature.

[0020] Further, the chemical strengthening includes ion exchange of potassium-sodium exchange and ion exchange of sodium-lithium exchange, wherein,

[0021] Perform ion exchange of potassium-sodium exchange for glass without lithium;

[0022] Perform ion exchange of sodium-lithium exchange and then perform ion exchange of potassium-sodium exchange for glass containing lithium.

[0023] Further, the lithium-free glass raw material formula consists of the following parts by mass: SiO2 60% - 62%, Al2O3 13% - 15%, MgO 5.5% - 6.5%, K2O 4% - 6%, Na2O 13% - 15%, ZrO2 0.6% - 0.8%.

[0024] Further, the lithium-containing glass raw material formula consists of the following parts by mass: SiO2 60% - 64%, Al2O3 18% - 20%, MgO 1% - 3%, K2O 0% - 3%, Na2O 6% - 8%, Li2O 4% - 6%.

[0025] Further, determine whether the chemical strengthening treatment meets the preset standard according to the strengthening warpage value, where

[0026] if the strengthening warpage value is less than the preset strengthening warpage value, it is determined that the chemical strengthening treatment meets the preset standard, and step S8 is executed;

[0027] if the strengthening warpage value is greater than or equal to the preset strengthening warpage value, it is determined that the chemical strengthening treatment does not meet the preset standard, and it is determined again whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value.

[0028] Further, determine again whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value, where

[0029] if the strength evaluation value is less than the first preset strength evaluation value, it is determined that the chemical strengthening treatment meets the preset standard, and step S8 is executed;

[0030] if the strength evaluation value is greater than or equal to the first preset strength evaluation value and less than the second preset strength evaluation value, it is determined that the chemical strengthening treatment does not meet the preset standard, and the temperature of the spraying area is increased according to the difference between the strength evaluation value and the first preset strength evaluation value;

[0031] if the strength evaluation value is greater than or equal to the second preset strength evaluation value, it is determined that the chemical strengthening treatment does not meet the preset standard, and the sodium / lithium content in the molten salt is reduced according to the difference between the strength evaluation value and the second preset strength evaluation value.

[0032] Further, the strength evaluation value is jointly determined by the surface compressive stress value and the surface compressive stress layer depth of the non-tin surface of the glass.

[0033] Further, increase the temperature of the spraying area according to the difference between the first strength evaluation differences, where

[0034] If the first strength evaluation difference is less than the first preset strength evaluation difference, use the first temperature adjustment coefficient to increase the temperature of the spraying area to the corresponding value;

[0035] If the first strength evaluation difference is greater than or equal to the first preset strength evaluation difference and less than the second preset strength evaluation difference, use the second temperature adjustment coefficient to increase the temperature of the spraying area to the corresponding value;

[0036] If the first strength evaluation difference is greater than or equal to the second preset strength evaluation difference, use the third temperature adjustment coefficient to increase the temperature of the spraying area to the corresponding value;

[0037] The first strength evaluation difference is the difference between the strength evaluation value and the first preset strength evaluation value.

[0038] Furthermore, the adjustment range of the sodium / lithium content in the molten salt is positively correlated with the second strength evaluation difference, where the second strength evaluation difference is the difference between the strength evaluation value and the second preset strength evaluation value.

[0039] Compared with the prior art, the beneficial effects of the present invention are that the ultra-thin aluminosilicate glass prepared by the present invention can reduce the warpage degree without grinding and polishing during the processing, ensuring the quality of the glass and reducing the processing cost.

[0040] Furthermore, the present invention does not use a large amount of acidic gases during the chemical strengthening process, reducing the potential risks to personnel and the environment in glass production.

[0041] Furthermore, the present invention sets the temperature above the glass strain point for ion exchange during the chemical strengthening process, and then anneals the stress generated by the ion exchange to eliminate the stress, so as to achieve the purpose of improving the warpage of chemical strengthening, ensuring that there is no obvious interface or mutation between the composition and performance of the product, and thus ensuring the stability of the product. Description of the Drawings

[0042] Figure 1 It is a flowchart of a method for preparing ultra-thin aluminosilicate glass according to an embodiment of the present invention;

[0043] Figure 2 It is a flowchart for determining whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value in an embodiment of the present invention;

[0044] Figure 3 It is a flowchart for adjusting the temperature of the spraying area according to the first strength evaluation difference in an embodiment of the present invention;

[0045] Figure 4 It is a flowchart for adjusting the sodium / lithium content in the molten salt according to the second strength evaluation difference in an embodiment of the present invention. Detailed implementation manners

[0046] In order to make the objectives and advantages of the present invention more clearly understood, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] The preferred implementation manners of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0048] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0049] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0050] Please refer to Figures 1 to 4 as shown in Figure 1 a flowchart of a method for preparing an ultra-thin aluminosilicate glass according to an embodiment of the present invention; Figure 2 a flowchart of determining whether a chemical strengthening treatment meets a preset standard according to a strength evaluation value in an embodiment of the present invention; Figure 3 a flowchart of adjusting the temperature of a spraying area according to a first strength evaluation difference in an embodiment of the present invention; Figure 4 a flowchart of adjusting the sodium / lithium content in a molten salt according to a second strength evaluation difference in an embodiment of the present invention.

[0051] The method for preparing an ultra-thin aluminosilicate glass according to an embodiment of the present invention includes:

[0052] Step S1, mixing SiO2, Al2O3, MgO, K2O, Na2O and ZrO2 / Li2O in proportion;

[0053] Step S2, feeding the mixed raw materials into a glass melting furnace for high-temperature melting to form a molten glass liquid;

[0054] Step S3, pour the molten glass liquid into a float bath filled with tin liquid to form a uniform glass ribbon on the surface of the tin liquid;

[0055] Step S4, let the glass ribbon in the tin bath stand still and cool until it solidifies to form flat glass;

[0056] Step S5, anneal the solidified flat glass and perform chemical strengthening during the annealing process;

[0057] Step S6, when it is determined that the chemical strengthening treatment does not meet the preset standard according to the strengthening warpage value, re - determine whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value;

[0058] Step S7, when it is re - determined that the chemical strengthening treatment does not meet the preset standard according to the strength evaluation value, increase the temperature of the spraying area according to the difference between the strength evaluation value and the first preset strength evaluation value, or reduce the sodium / lithium content in the molten salt according to the difference between the strength evaluation value and the second preset strength evaluation value;

[0059] Step S8, cut the flat glass that meets the preset standard after chemical strengthening treatment to obtain ultra - thin aluminosilicate glass.

[0060] Specifically, the chemical strengthening includes ion exchange of potassium - sodium exchange and ion exchange of sodium - lithium exchange, where

[0061] Perform ion exchange of potassium - sodium exchange for glass without lithium;

[0062] Perform ion exchange of sodium - lithium exchange and then potassium - sodium exchange for glass containing lithium.

[0063] Specifically, the chemical strengthening process for glass without lithium includes:

[0064] Step S501, heat the glass from room temperature to 380 °C within 40 - 60 min;

[0065] Step S502, spray a layer of molten salt on the non - tin surface of the glass for ion exchange, where the ion exchange temperature is 420 °C and the ion exchange duration is 5 h;

[0066] Step S503, keep the glass at 380 °C, the glass annealing point, for a preset duration of 5 min;

[0067] Step S504, cool the glass to room temperature within 40 min.

[0068] Specifically, step S502 in the chemical strengthening process for glass containing lithium includes:

[0069] Sodium-lithium exchange, the molten salt temperature is 440 °C, and the ion exchange duration is 90 min;

[0070] Potassium-sodium exchange, the molten salt temperature is 420 °C, and the ion exchange duration is 90 min.

[0071] Specifically, in the chemical strengthening process of the lithium-containing glass, step S504 requires rapid cooling of the glass to room temperature within 10 min, and the specific duration is not limited and can be determined according to the actual production situation.

[0072] Specifically, the glass raw material formula without lithium consists of the following parts by mass: SiO2 60% - 62%, Al2O3 13% - 15%, MgO 5.5% - 6.5%, K2O 4% - 6%, Na2O 13% - 15%, ZrO2 0.6% - 0.8%.

[0073] Specifically, the glass raw material formula containing lithium consists of the following parts by mass: SiO2 60% - 64%, Al2O3 18% - 20%, MgO 1% - 3%, K2O 0% - 3%, Na2O 6% - 8%, Li2O 4% - 6%.

[0074] Specifically, it is determined whether the chemical strengthening treatment meets the preset standard according to the strengthening warpage value, where

[0075] If the strengthening warpage value is less than the preset strengthening warpage value of 0.40 mm, it is determined that the chemical strengthening treatment meets the preset standard, and step S8 is executed;

[0076] If the strengthening warpage value is greater than or equal to the preset strengthening warpage value, it is determined that the chemical strengthening treatment does not meet the preset standard, and it is determined again whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value.

[0077] Specifically, it is determined again whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value, where

[0078] If the strength evaluation value is less than the first preset strength evaluation value of 1.05, it is determined that the chemical strengthening treatment meets the preset standard, and step S8 is executed;

[0079] If the strength evaluation value is greater than or equal to the first preset strength evaluation value and less than the second preset strength evaluation value of 1.10, it is determined that the chemical strengthening treatment does not meet the preset standard, and the temperature of the spraying area is increased according to the difference between the strength evaluation value and the first preset strength evaluation value;

[0080] If the strength evaluation value is greater than or equal to the second preset strength evaluation value, it is determined that the chemical strengthening treatment does not meet the preset standard, and the sodium / lithium content in the molten salt is reduced according to the difference between the strength evaluation value and the second preset strength evaluation value.

[0081] Specifically, the process of jointly determining the strength evaluation value by the surface compressive stress value and the surface compressive stress layer depth on the non-tin side of the glass includes:

[0082] Taking the square root of the ratio of the surface compressive stress value to the surface compressive stress threshold and assigning a first evaluation coefficient to obtain the surface compressive stress evaluation value, where the first evaluation coefficient is 0.55 and the surface compressive stress threshold is 800 MPa;

[0083] Taking the square root of the ratio of the surface compressive stress layer depth to the surface compressive stress layer depth threshold and assigning a second evaluation coefficient to obtain the surface compressive stress layer depth evaluation value, where the second evaluation coefficient is 0.42 and the surface compressive stress layer depth threshold is 40 μm;

[0084] Adding the surface compressive stress evaluation value and the surface compressive stress layer depth evaluation value and recording it as the strength evaluation value.

[0085] Specifically, it is characterized in that the temperature of the spraying area is increased according to the difference between the first strength evaluation differences, where

[0086] If the first strength evaluation difference is less than the first preset strength evaluation difference of 0.02, the temperature of the spraying area is increased to the corresponding value using the first temperature adjustment coefficient of 1.01;

[0087] If the first strength evaluation difference is greater than or equal to the first preset strength evaluation difference and less than the second preset strength evaluation difference of 0.04, the temperature of the spraying area is increased to the corresponding value using the second temperature adjustment coefficient of 1.03;

[0088] If the first strength evaluation difference is greater than or equal to the second preset strength evaluation difference, the temperature of the spraying area is increased to the corresponding value using the third temperature adjustment coefficient of 1.05;

[0089] The first strength evaluation difference is the difference between the strength evaluation value and the first preset strength evaluation value.

[0090] Specifically, the adjustment range of the sodium / lithium content in the molten salt is positively correlated with the second strength evaluation difference, where

[0091] If the second strength evaluation difference is less than the third preset strength evaluation difference, the sodium / lithium content in the molten salt is reduced to the corresponding value using the first content adjustment coefficient of 0.99;

[0092] If the second strength evaluation difference is greater than or equal to the third preset strength evaluation difference and less than the fourth preset strength evaluation difference, use the second content adjustment coefficient 0.97 to reduce the sodium / lithium content in the molten salt to the corresponding value;

[0093] If the second strength evaluation difference is greater than or equal to the fourth preset strength evaluation difference, use the third content adjustment coefficient 0.95 to reduce the sodium / lithium content in the molten salt to the corresponding value;

[0094] The second strength evaluation difference is the difference between the strength evaluation value and the second preset strength evaluation value.

[0095] Specifically, for the enhanced warping, a feeler gauge is used to test the warping at four corners.

[0096] Specifically, the equipment used for testing the sodium / lithium content is the X-ray fluorescence spectrometer ARL Perform'X.

[0097] Specifically, the CS value is the surface compressive stress value after chemical strengthening, which is measured by the equipment Orihara FSM6000Le.

[0098] Specifically, the DOL value is the depth of the surface compressive stress layer after chemical strengthening, which is measured by the equipment Orihara FSM6000Le.

[0099] Specifically, the CS30 value is the compressive stress value at a depth of 30 microns after chemical strengthening, and the equipment used for testing is the Orihara SLP2000 equipment;

[0100] Specifically, the DOL-Na value is the depth of the compressive stress layer where Na and Li are replaced after chemical strengthening, and the equipment used for testing is the Orihara SLP2000 equipment.

[0101] The present invention will be further described below in conjunction with embodiments:

[0102] Comparative Example 1

[0103] The embodiment of the present invention provides an ultra-thin aluminosilicate glass without lithium, wherein,

[0104] Molten salt composition (wt%): None;

[0105] Sodium / lithium content in the spraying solution: None;

[0106] Temperature of the spraying area (°C): None.

[0107] Example 1

[0108] The embodiment of the present invention provides an ultra-thin aluminosilicate glass without lithium, wherein,

[0109] Molten salt composition (wt%): KNO3;

[0110] Sodium / lithium content of spraying solution (ppm): 0;

[0111] Temperature of spraying area (°C): 600.

[0112] Example 2

[0113] An embodiment of the present invention provides an ultra-thin aluminosilicate glass without lithium, wherein the molten salt composition (wt%): KNO3 90%, NaNO3 10%;

[0114] Sodium / lithium content of spraying solution (ppm): 27049;

[0115] Temperature of spraying area (°C): 600.

[0116] Example 3

[0117] An embodiment of the present invention provides an ultra-thin aluminosilicate glass without lithium, wherein the molten salt composition (wt%): KNO3 70%, NaNO3 29%, NaOH 1%; sodium / lithium content of spraying solution (ppm): 84189;

[0118] Temperature of spraying area (°C): 600.

[0119] Example 4

[0120] An embodiment of the present invention provides an ultra-thin aluminosilicate glass without lithium, wherein the molten salt composition (wt%): KNO3;

[0121] Sodium / lithium content of spraying solution (ppm): 0;

[0122] Temperature of spraying area (°C): 575.

[0123] Example 5

[0124] An embodiment of the present invention provides an ultra-thin aluminosilicate glass without lithium, wherein the molten salt composition (wt%): KNO3;

[0125] Sodium / lithium content of spraying solution (ppm): 0;

[0126] Temperature of spraying area (°C): 585.

[0127] Example 6

[0128] An embodiment of the present invention provides an ultra-thin aluminosilicate glass without lithium, wherein the molten salt composition (wt%): KNO3;

[0129] Sodium / lithium content of spraying solution (ppm): 0;

[0130] Temperature of spraying area (°C): 595.

[0131] The enhanced warpage values of Comparative Example 1, Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6 were detected respectively. The specific results are shown in Table 1 below:

[0132]

[0133] The surface compressive stress values and the surface compressive stress layer depths of the non-tin side and the tin side of Comparative Example 1, Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6 were detected respectively. The specific results are shown in Table 2 below:

[0134]

[0135] From the comparison between Comparative Example 1 and Examples 1-6 in Table 1 and Table 2, it can be seen that the present invention reduces the enhanced warpage value of the lithium-free ultra-thin aluminosilicate glass by adjusting the sodium content of the spraying solution and the temperature of the spraying area in the preparation process. At the same time, both the surface compressive stress value and the surface compressive stress layer depth of the non-tin side are reduced, which proves that the adjustment of the present invention reduces the glass warpage caused by chemical strengthening and thus improves the quality of the glass.

[0136] Comparative Example 2

[0137] An embodiment of the present invention provides a lithium-containing ultra-thin aluminosilicate glass, wherein the molten salt composition (wt%): none;

[0138] Lithium content of the spraying solution: none;

[0139] Temperature of the spraying area (°C): none.

[0140] Example 7

[0141] An embodiment of the present invention provides a lithium-containing ultra-thin aluminosilicate glass, wherein the molten salt composition (wt%): NaNO3;

[0142] Lithium content of the spraying solution (ppm): 0;

[0143] Temperature of the spraying area (°C): 555.

[0144] Example 8

[0145] An embodiment of the present invention provides a lithium-containing ultra-thin aluminosilicate glass, wherein the molten salt composition (wt%): 40% NaNO3, 60% KNO3;

[0146] Sodium / lithium content of the spraying solution (ppm): 0;

[0147] Temperature of the spraying area (°C): 555

[0148] Example 9

[0149] An embodiment of the present invention provides a lithium-containing ultra-thin aluminosilicate glass. Among them, the molten salt composition (wt%): NaNO3 40%, KNO3 58%, LiNO3 2%; the sodium / lithium content in the spraying solution (ppm): 2013

[0150] Temperature of the spraying area (°C): 555

[0151] Example 10

[0152] An embodiment of the present invention provides a lithium-containing ultra-thin aluminosilicate glass. Among them, the molten salt composition (wt%): NaNO3 40%, KNO3 55%, LiNO3 5%; the sodium / lithium content in the spraying solution (ppm): 5033;

[0153] Temperature of the spraying area (°C): 555.

[0154] Example 11

[0155] An embodiment of the present invention provides a lithium-containing ultra-thin aluminosilicate glass. Among them, the molten salt composition (wt%): NaNO3 40%, KNO3 60%;

[0156] The sodium / lithium content in the spraying solution (ppm): 0;

[0157] Temperature of the spraying area (°C): 540.

[0158] Example 12

[0159] An embodiment of the present invention provides a lithium-containing ultra-thin aluminosilicate glass, among which,

[0160] The molten salt composition (wt%): NaNO3 40%, KNO3 60%;

[0161] The sodium / lithium content in the spraying solution (ppm): 0;

[0162] Temperature of the spraying area (°C): 530.

[0163] The strengthening warpage values of Comparative Example 2, Example 7, Example 8, Example 9, Example 10, Example 11 and Example 12 were detected respectively. The specific results are shown in Table 3 below:

[0164]

[0165] The surface compressive stress values and the surface compressive stress layer depths of the non-tin surface and the tin surface of Comparative Example 2, Example 7, Example 8, Example 9, Example 10, Example 11 and Example 12 were detected respectively. The specific results are shown in Table 4 below:

[0166]

[0167] It can be seen from the comparison between Comparative Example 2 and Examples 7-12 in Table 3 and Table 4 that by adjusting the lithium content of the spraying solution and the temperature of the spraying area in the preparation process, the present invention reduces the strengthening warpage value of the lithium-containing ultra-thin aluminosilicate glass. At the same time, the surface compressive stress value and the depth of the surface compressive stress layer on the non-tin surface are both reduced, proving that the adjustment of the present invention reduces the glass warpage caused by chemical strengthening, thereby improving the quality of the glass.

[0168] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0169] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an ultra-thin aluminosilicate glass, characterized in that, Including: Step S1: Mix SiO2, Al2O3, MgO, K2O, Na2O, and ZrO2 / Li2O in proportion; Step S2: Feed the mixed raw materials into a glass melting furnace for high-temperature melting to form molten glass; Step S3: Pour the molten glass into a float bath filled with tin liquid to form a uniform glass ribbon on the surface of the tin liquid; Step S4: Let the glass ribbon in the tin bath stand and cool until it solidifies to form flat glass; Step S5: Anneal the solidified flat glass and perform chemical strengthening during the annealing process; Step S6: When it is determined that the chemical strengthening treatment does not meet the preset standard according to the strengthening warpage value, re-determine whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value; Step S7: When it is determined that the chemical strengthening treatment does not meet the preset standard according to the strength evaluation value after re-determination, increase the temperature of the spraying area according to the difference between the strength evaluation value and the first preset strength evaluation value, or reduce the sodium / lithium content in the molten salt according to the difference between the strength evaluation value and the second preset strength evaluation value; Step S8: Cut the flat glass that meets the preset standard of chemical strengthening treatment to obtain ultra-thin aluminosilicate glass; Determine whether the chemical strengthening treatment meets the preset standard according to the strengthening warpage value, where if the strengthening warpage value is less than the preset strengthening warpage value, it is determined that the chemical strengthening treatment meets the preset standard, and step S8 is executed; if the strengthening warpage value is greater than or equal to the preset strengthening warpage value, it is determined that the chemical strengthening treatment does not meet the preset standard, and re-determine whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value; Re-determine whether the chemical strengthening treatment meets the preset standard according to the strength evaluation value, where if the strength evaluation value is less than the first preset strength evaluation value, it is determined that the chemical strengthening treatment meets the preset standard, and step S8 is executed; if the strength evaluation value is greater than or equal to the first preset strength evaluation value and less than the second preset strength evaluation value, it is determined that the chemical strengthening treatment does not meet the preset standard, and increase the temperature of the spraying area according to the difference between the strength evaluation value and the first preset strength evaluation value; if the strength evaluation value is greater than or equal to the second preset strength evaluation value, it is determined that the chemical strengthening treatment does not meet the preset standard, and reduce the sodium / lithium content in the molten salt according to the difference between the strength evaluation value and the second preset strength evaluation value.

2. The method for preparing an ultra-thin aluminosilicate glass according to claim 1, wherein The chemical strengthening process includes: Step S501: Preheat the glass to a temperature close to the melting point of the molten salt; Step S502: Spray a layer of molten salt on the non-tin surface of the glass for ion exchange; Step S503: Keep the glass at the glass annealing point for a preset duration; Step S504: Cool the glass to room temperature.

3. The method for preparing the ultra-thin aluminosilicate glass according to claim 2, characterized in that, The chemical strengthening includes ion exchange of potassium-sodium exchange and ion exchange of sodium-lithium exchange, where Ion exchange of potassium-sodium exchange is performed for glass without lithium; Ion exchange of sodium-lithium exchange is performed for glass containing lithium, and then ion exchange of potassium-sodium exchange is performed.

4. The method for preparing the ultra-thin aluminosilicate glass according to claim 3, wherein The lithium-free glass raw material formula consists of the following parts by mass: SiO2 60% - 62%, Al2O3 13% - 15%, MgO 5.5% - 6.5%, K2O 4% - 6%, Na2O 13% - 15%, ZrO2 0.6% - 0.8%.

5. The method for preparing an ultra-thin aluminosilicate glass according to claim 4, wherein, The lithium-containing glass raw material formula consists of the following parts by mass: SiO2 60% - 64%, Al2O3 18% - 20%, MgO 1% - 3%, K2O 0% - 3%, Na2O 6% - 8%, Li2O 4% - 6%.

6. The method for preparing an ultra-thin aluminosilicate glass according to claim 5, characterized in that, The strength evaluation value is jointly determined by the surface compressive stress value and the surface compressive stress layer depth of the non-tin side of the glass.

7. The method for preparing an ultra-thin aluminosilicate glass according to claim 6, characterized in that, Increase the temperature of the spraying area according to the difference between the first strength evaluation differences, where if the first strength evaluation difference is less than the first preset strength evaluation difference, use the first temperature adjustment coefficient to increase the temperature of the spraying area to the corresponding value; if the first strength evaluation difference is greater than or equal to the first preset strength evaluation difference and less than the second preset strength evaluation difference, use the second temperature adjustment coefficient to increase the temperature of the spraying area to the corresponding value; if the first strength evaluation difference is greater than or equal to the second preset strength evaluation difference, use the third temperature adjustment coefficient to increase the temperature of the spraying area to the corresponding value; The first strength evaluation difference is the difference between the strength evaluation value and the first preset strength evaluation value.

8. The method for preparing an ultra-thin aluminosilicate glass according to claim 7, wherein, The adjustment range of the sodium / lithium content in the molten salt is positively correlated with the second strength evaluation difference, where the second strength evaluation difference is the difference between the strength evaluation value and the second preset strength evaluation value.

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