Modified mother glass as well as preparation method and application thereof

Abstract

The invention relates to the technical field of electronic glass, and provides modified mother glass as well as a preparation method and application thereof. The modified mother glass comprises an air surface layer and a tin surface layer, the air surface layer and the tin surface layer both contain beta-OH, and the difference value of the beta-OH value in the air surface layer and the beta-OH value in the tin surface layer is smaller than or equal to 0.04 mm <-1 >. According to the modified mother glass disclosed by the embodiment of the invention, the beta-OH value of the air surface layer and the beta-OH value of the tin surface layer are controlled to be within a specific range, so that the beta-OH value difference of the air surface layer and the tin surface layer is reduced, and the stress difference caused by the beta-OH value difference after ion exchange of the air surface layer and the tin surface layer is reduced; the warping of the modified mother glass after chemical strengthening is reduced.

Description

Technical Field

[0001] This application belongs to the technical field of electronic glass, and particularly relates to a modified plain glass, a preparation method thereof, and an application thereof. Background Art

[0002] Chemical strengthening treatment can improve the strength, scratch resistance, and impact resistance of ultra-thin cover glass, so that the cover glass can meet the performance requirements of mobile displays such as mobile phones and tablet computers. Since the glass produced by the float process has good flatness, transparency, and reliability, the glass produced by the float process is often used for chemical strengthening to prepare ultra-thin cover glass.

[0003] However, in the prior art, the plain glass produced by the float process has a tin side and an air side, and the components of the tin side and the air side in the plain glass are different, resulting in different ion exchange rates of the tin side and the air side during the subsequent chemical strengthening process. Eventually, the CS (surface compressive stress) and DOL (ion exchange depth) on both sides of the strengthened glass are inconsistent, and the glass warps, which seriously affects the use of the cover glass. Summary of the Invention

[0004] The purpose of this application is to provide a modified plain glass and a preparation method thereof to solve the technical problem that the plain glass in the prior art is prone to warping after chemical strengthening.

[0005] This application embodiment also provides a chemically strengthened glass, a preparation method thereof, a cover glass, and an electronic device.

[0006] To achieve the above application purpose, the technical solution adopted in this application is as follows:

[0007] In the first aspect, this application embodiment provides a modified plain glass. The modified plain glass in this application embodiment includes an air surface layer and a tin surface layer. Among them, both the air surface layer and the tin surface layer contain β-OH, and the difference between the β-OH value in the air surface layer and the β-OH value in the tin surface layer ≤ 0.04 mm -1 .

[0008] The modified plain glass in this application embodiment controls the difference in β-OH value between the air surface layer and the tin surface layer within ≤ 0.04 mm -1 range, reducing the difference in β-OH value between the air surface layer and the tin surface layer, thereby reducing the stress difference caused by the difference in β-OH value after ion exchange between the air surface layer and the tin surface layer, and reducing the warping of the modified plain glass in this application embodiment after chemical strengthening.

[0009] In the second aspect, this application embodiment provides a preparation method of the above-mentioned modified plain glass. The preparation method of the modified plain glass in this application embodiment includes the following steps:

[0010] Place the air side of the plain glass in a modification solution for modification treatment to obtain a modified plain glass, where the modification solution contains hydrogen peroxide.

[0011] In the method for preparing the modified plain glass according to the embodiment of the present application, the air side of the plain glass is modified with a modification solution containing hydrogen peroxide, which promotes the formation of β-OH in the air layer of the plain glass, increases the β-OH value of the air layer, and reduces the β-OH value difference between the air layer and the tin layer. Since the β-OH value difference between the air layer and the tin layer of the modified plain glass prepared by the method for preparing the modified plain glass according to the embodiment of the present application is small, the stress difference between the air layer and the tin layer of the modified plain glass after chemical strengthening treatment is small, thereby effectively reducing the warpage value of the obtained chemically strengthened glass. In addition, the process steps of the method for preparing the plain glass according to the embodiment of the present application are few, the production process is easy to control, and it is convenient for large-scale industrial production.

[0012] In the third aspect, the embodiment of the present application provides a chemically strengthened glass. The chemically strengthened glass according to the embodiment of the present application is prepared by chemically strengthening the above-mentioned modified plain glass.

[0013] Since the β-OH value difference between the air layer and the tin layer of the modified plain glass according to the embodiment of the present application is small, the influence of β-OH in the air layer and the tin layer on the stress after chemical strengthening of the glass is similar, so that the stress between the air layer and the tin layer of the chemically strengthened glass according to the embodiment of the present application is similar, and the warpage value of the chemically strengthened glass is low.

[0014] In the fourth aspect, the embodiment of the present application provides a method for preparing a chemically strengthened glass. The method for preparing the chemically strengthened glass according to the embodiment of the present application includes the following steps:

[0015] Chemically strengthen the modified plain glass to obtain a chemically strengthened glass; where the modified plain glass is the above-mentioned modified plain glass.

[0016] In the method for preparing the chemically strengthened glass according to the embodiment of the present application, the β-OH value difference between the air layer and the tin layer of the modified plain glass used is small, so that the stress difference between the air layer and the tin layer of the obtained chemically strengthened glass is small, and the warpage value of the chemically strengthened glass is low.

[0017] In the fifth aspect, the embodiment of the present application provides a cover glass. The cover glass according to the embodiment of the present application is made from the above-mentioned chemically strengthened glass.

[0018] Based on the low warpage value of the above-mentioned chemically strengthened glass, the cover glass according to the embodiment of the present application has a low warpage value and good flatness. Furthermore, the cover glass according to the embodiment of the present application can better closely fit with other components of the electronic device, improve the yield rate during the production of the electronic device, reduce the production cost at the same time, enhance the response speed and display quality of the touch screen, and enhance the user experience.

[0019] In a sixth aspect, an embodiment of the present application provides an electronic device. The electronic device in the embodiment of the present application includes the cover glass described above.

[0020] Since the cover glass described above has a low warpage value and high strength, the touch screen of the electronic device in the embodiment of the present application has a fast response speed, high display quality, and good user experience. Detailed implementation manners

[0021] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present application clearer, the present application will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0022] In the present application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may indicate: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0023] In the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one (item)" or a similar expression thereof refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, "at least one (item) of a, b, or c", or, "at least one (item) of a, b, and c" can both indicate: a, b, c, a~b (i.e., a and b), a~c, b~c, or a~b~c, where a, b, and c can be single or multiple respectively.

[0024] It should be understood that in various embodiments of the present application, the magnitude of the serial numbers of the above processes does not mean the order of execution. Some or all of the steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0025] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0026] In the description of the embodiments of the present application, the weight of the relevant components mentioned not only can refer to the specific content of each component, but also can represent the proportional relationship of the weights between the components. Therefore, as long as the content of the relevant components in the description of the embodiments of the present application is scaled up or down proportionally, it is within the scope disclosed in the description of the embodiments of the present application. Specifically, the mass in the description of the embodiments of the present application can be mass units well-known in the chemical industry such as μg, mg, g, kg, etc.

[0027] The terms "first" and "second" are only used for descriptive purposes to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX can also be referred to as the second XX. Similarly, the second XX can also be referred to as the first XX. Thus, the features defined with "first" and "second" can explicitly or implicitly include one or more of such features.

[0028] To solve the technical problem that the plain glass is prone to warping after chemical strengthening in the prior art, the present application proposes the following technical solutions.

[0029] In a first aspect, the embodiments of the present application provide a modified plain glass. The modified plain glass of the embodiments of the present application includes an air layer and a tin layer. Both the air layer and the tin layer contain β-OH, and the difference between the β-OH value in the air layer and the β-OH value in the tin layer ≤ 0.04 mm -1 。

[0030] By controlling the difference between the β-OH value of the air layer and the β-OH value of the tin layer within a specific range, the modified plain glass of the embodiments of the present application effectively reduces the stress difference between the air layer and the tin layer of the modified plain glass after chemical strengthening treatment, thereby reducing the warping value of the modified plain glass after chemical strengthening treatment.

[0031] It should be noted that β-OH in the embodiments of the present application refers to the hydroxyl value contained in the modified plain glass. In some embodiments, the β-OH values of the air layer and the tin layer of the modified plain glass can be measured by the following measurement method: Use FT-IR to measure the transmittance, and calculate the value obtained by the formula β-OH = (1 / X)log(T1 / T2). Wherein, X: plate thickness (mm); T1: transmittance (%) at the reference wavelength of 3846 cm -1 ; T2: transmittance (%) at the reference wavelength of 3600 cm -1 。

[0032] In some embodiments, the modified plain glass of the present application embodiment can be obtained by subjecting plain glass produced by the float process to a modification treatment. Among them, the tin side of the modified plain glass is the surface that contacts the tin bath when preparing the plain glass by the float process, and the tin layer is the glass matrix on one side of the modified plain glass that includes the tin side; the air side is the upper surface that does not contact the tin bath when preparing the plain glass by the float process, and the air layer is the glass matrix on one side of the modified plain glass that includes the air side. It should be noted that the gas in the furnace when preparing the plain glass can be air or other gases, such as inert gases like nitrogen, etc., and there is no specific limitation.

[0033] It should be noted that in the modified plain glass of the present application embodiment, when the depths of the tin layer and the air layer are the same, the β-OH value of the air layer can be higher than the β-OH value of the tin layer, the β-OH value of the air layer can also be lower than the β-OH value of the tin layer, and the β-OH value of the air layer can also be the same as the β-OH value of the tin layer. There is no specific limitation, as long as the difference in β-OH value between the air layer and the tin layer ≤ 0.04 mm -1 That's all. Among them, the depth of the air layer is the depth from the air side of the glass matrix to the tin side, and the depth of the tin layer is the depth from the tin side of the glass matrix to the air side. In the demonstration example, the difference in β-OH value between the air layer and the tin layer can be ≤ 0.01 mm -1 ≤ 0.02 mm -1 ≤ 0.03 mm -1 and other typical but non-limiting sizes.

[0034] In some embodiments, the thickness of the modified plain glass can be 0.1 - 2 mm, and can be selected as 0.1 - 1 mm, 0.1 - 1.5 mm, 0.2 - 2 mm, 0.5 - 2 mm, 0.5 - 1 mm. In the demonstration example, the thickness of the modified plain glass can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm and other typical but non-limiting thicknesses, or any thickness size between any two numerical ranges. Controlling the thickness of the modified plain glass within this range can effectively reduce the thickness of the subsequent produced cover glass, and at the same time further reduce the warpage value after chemical strengthening of the modified plain glass.

[0035] In some embodiments, by mass percentage, the modified plain glass can include the following components:

[0036] SiO 2 55% - 65%;

[0037] Al 2 O3 10% to 20%;

[0038] Na 2 O 10% to 18%;

[0039] K 2 O 3% to 8%;

[0040] MgO 3% to 8%;

[0041] ZrO 2 0% to 2%

[0042] CaO 0% to 5%.

[0043] In some embodiments, by mass percentage, the modified base glass may include the following components:

[0044] SiO 2 55% to 70%;

[0045] Al 2 O 3 15% to 25%;

[0046] Li 2 O 3% to 8%;

[0047] Na 2 O 5% to 10%;

[0048] K 2 O 0 to 3%;

[0049] MgO 0 to 5%;

[0050] ZrO 2 0 to 3%

[0051] CaO 0 to 5%.

[0052] Controlling the content of each component in the modified base glass within this range can further improve the properties of the modified base glass such as light transmittance, chemical stability, hardness, scratch resistance, and impact resistance after chemical strengthening treatment.

[0053] In some embodiments, the β-OH in the embodiments of the present application may be β-OH connected to silicon. In the modified base glass, silicon β-OH is the main form of the existence of β-OH. By controlling the difference in the silicon β-OH value between the air surface layer and the tin surface layer, the difference in the β-OH value can be effectively controlled, thereby reducing the stress difference between the two sides of the glass after ion exchange caused by the β-OH value difference, and further reducing the warpage value of the chemically strengthened glass.

[0054] In some embodiments, in the present application embodiments, the depth of the modified plain glass air layer and tin layer is in the range of 0 to 10 μm, and the difference in sodium content between the tin layer and the air layer can be 0.4% to 0.8%. In further embodiments, in the range where the depth of the air layer and the tin layer is 0 to 10 μm, the difference in sodium content between the tin layer and the air layer can be typical but non-limiting values such as 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, and any value between any two numerical ranges. Sodium ions are alkali metal ions. When the sodium content decreases, during the chemical strengthening treatment of the modified plain glass, the ion exchange ability of the glass decreases. Controlling the difference in sodium content between the air layer and the tin layer in the present application embodiments within this range further reduces the difference in ion exchange ability between the air layer and the tin layer of the modified plain glass, thereby further reducing the difference in ion exchange depth and strength between the air layer and the tin layer after the ion exchange treatment, and reducing the warpage of the plain glass after chemical strengthening.

[0055] In some embodiments, the method for measuring the Na content can be: using an XRF fluorescence spectrometer to detect the surface to be measured to obtain the Na content of the surface to be measured. It should be noted that in this solution, the Na content is the mass percentage of Na 2 O.

[0056] In a second aspect, the present application embodiments provide a method for preparing the modified plain glass described above. The method for preparing the modified plain glass in the present application embodiments includes the following steps:

[0057] Placing the air surface of the plain glass in a modification solution for modification treatment to obtain a modified plain glass, wherein the modification solution contains hydrogen peroxide.

[0058] The method for preparing the modified plain glass in the present application embodiments modifies the air surface of the plain glass with a modification solution containing hydrogen peroxide, so that hydrogen peroxide weakens the strength of the Si-O bonds in the air layer, which is conducive to the erosion of the Si-O bonds by water to form Si-OH, increases the β-OH value of the air layer, and reduces the difference in β-OH value between the air layer and the tin layer. Since the difference in β-OH value between the air layer and the tin layer of the modified plain glass prepared by the preparation method of the present application embodiments is small, when the modified plain glass is subjected to chemical strengthening treatment, the difference in ion exchange rate and exchange depth between the air layer and the tin layer is small, and further, the stress difference between the air layer and the tin layer of the chemically strengthened glass obtained after the chemical strengthening treatment of the modified plain glass is small, and the warpage value of the chemically strengthened glass is low.

[0059] In some embodiments, the concentration of hydrogen peroxide in the modification solution can be 3% to 30%, optionally 5% to 15%, 5% to 20%, 5% to 30%. In exemplary embodiments, the concentration of hydrogen peroxide in the modification solution can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30% and other typical but non-limiting values, or any value between any two numerical ranges. Controlling the concentration of hydrogen peroxide in the modification solution within this range, combined with parameters such as the temperature and time of the modification treatment, further reduces the difference in β-OH values between the air surface layer and the tin surface layer in the prepared modified soda-lime glass, thereby further reducing the warpage value of the modified soda-lime glass after chemical strengthening treatment.

[0060] In some embodiments, the modification solution may further contain inorganic acid. In exemplary embodiments, the inorganic acid may include at least one of hydrochloric acid, sulfuric acid, and nitric acid. When preparing soda-lime glass, since Na volatilization occurs, and the tin surface is in direct contact with the tin bath, the volatilization amount of sodium ions in the tin surface layer is less than that in the air surface, resulting in a higher sodium ion content in the tin surface layer than in the air surface. However, after exiting the tin bath, SO 2 gas is sprayed on the tin surface, and SO 2 will perform a dealkalization treatment on the tin surface, reducing the Na content of the tin surface and narrowing the difference in Na content between the tin surface and the air surface. In this solution, adding inorganic acid to the modification solution can perform a dealkalization reaction on the air surface layer, reducing the sodium content of the air surface layer, and further increasing the difference in Na content between the tin surface and the air surface. Since the β-OH value has a greater impact on the degree of chemical strengthening than the Na content on the chemical degree, when the β-OH value of the air surface is less than that of the tin surface, by further reducing the Na content of the air surface and appropriately increasing the difference in Na content between the tin surface and the air surface, it is beneficial to make the chemical strengthening degrees of the tin surface and the air surface close, thereby further reducing the warpage value of the modified soda-lime glass after chemical strengthening treatment. At the same time, adding acid to the modification solution can also promote the formation of Si-OH and increase the Si-OH content of the air surface, thereby further reducing the difference in β-OH values between the air surface layer and the tin surface layer.

[0061] In some embodiments, the difference in β-OH values and the difference in Na content can be controlled within a certain controllable range by controlling the value of M within a certain range, where M = |0.6*(β-OH value of the tin surface layer / β-OH value of the air surface layer) - 0.4*(Na content of the tin surface layer / Na content of the air surface layer)|. In further embodiments, the range of the M value can be 0 to 0.25. In exemplary embodiments, the M value can be 0.1, 0.15, 0.2, 0.25 and other typical but non-limiting values, or any value between any two numerical ranges.

[0062] In a further embodiment, the content of the inorganic acid in the modification solution may be 1% to 5%, optionally 1% to 4%, 2% to 5%, 3% to 5%; the content of hydrogen peroxide may be 3% to 30%; optionally, 5% to 15%, 5% to 20%, 5% to 30%. In the demonstration example, the content of the inorganic acid in the modification solution may be typical but non-limiting sizes such as 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc., or sizes between any two numerical ranges. Controlling the content of the inorganic acid in the modification solution within this range, combined with parameters such as the concentration of hydrogen peroxide, the time, and the temperature of the modification treatment, appropriately increases the sodium content difference between the air surface layer and the tin surface layer of the modified soda-lime glass, and further reduces the β-OH value difference between the air surface layer and the tin surface layer, reducing the warpage of the modified soda-lime glass after chemical strengthening treatment.

[0063] In some embodiments, the temperature of the modification treatment may be 20 to 85 °C, optionally 20 to 80 °C, 20 to 50 °C, 40 to 85 °C, 40 to 50 °C, 50 to 80 °C; the time of the modification treatment may be 0.5 to 4 h, optionally 1 to 4 h, 0.5 to 3 h, 1 to 3 h, 2 to 3 h. In the demonstration example, the temperature of the modification treatment may be typical but non-limiting temperatures such as 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, etc., or any temperature between any two numerical ranges; the time of the modification treatment may be typical but non-limiting times such as 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, etc., or any time between any two numerical ranges. Controlling the temperature and time of the modification treatment within this range, combined with the content range of hydrogen peroxide, etc. in the modification solution, further promotes the reaction of β-OH formation, increases the formation of β-OH in the air surface layer, further reduces the β-OH value difference between the air surface layer and the tin surface layer, and appropriately increases the sodium content difference between the air surface layer and the tin surface layer, thereby further reducing the warpage value of the modified soda-lime glass after chemical strengthening treatment.

[0064] In some embodiments, the thickness of the plain glass used in the method for preparing the modified plain glass according to the embodiments of the present application may be 0.1 to 2 mm, optionally 0.1 to 1 mm, 0.1 to 4.5 mm, 0.2 to 2 mm, 0.5 to 2 mm, 0.5 to 1 mm. In exemplary embodiments, the thickness of the modified plain glass may be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm and other typical but non-limiting thicknesses, or any thickness value between any two numerical ranges. Controlling the thickness of the modified plain glass within this range can effectively reduce the thickness and warpage of the subsequent obtained cover glass.

[0065] In some embodiments, the components of the plain glass used in the method for preparing the modified plain glass according to the embodiments of the present application may be as follows:

[0066] SiO 2 55% - 65%

[0067] Al 2 O 3 10% - 20%

[0068] Na 2 O 10% - 18%

[0069] K 2 O 3% - 8%

[0070] MgO 3% - 8%

[0071] ZrO 2 0 - 2%

[0072] CaO 0 - 5%.

[0073] In other embodiments, the components of the plain glass used in the method for preparing the modified plain glass according to the embodiments of the present application may be as follows:

[0074]

[0075] Using the plain glass with each component within these content ranges to prepare the modified plain glass can further improve the properties such as chemical stability, hardness, scratch resistance, impact resistance and light transmittance of the modified plain glass after chemical strengthening treatment, and at the same time further reduce the warpage of the modified plain glass after chemical strengthening treatment.

[0076] In a third aspect, the embodiments of the present application provide a chemically strengthened glass. The chemically strengthened glass according to the embodiments of the present application is obtained by chemically strengthening the modified plain glass described above.

[0077] Due to the small difference in the β-OH values between the modified plain glass tin surface layer and the air surface layer in the above text, after the modified plain glass undergoes chemical strengthening treatment, the stress difference between the air surface layer and the tin surface layer is small, resulting in a low warpage value of the chemically strengthened glass in the embodiments of the present application.

[0078] In some embodiments, the warpage value of the chemically strengthened glass in the embodiments of the present application can be less than or equal to 0.38 mm. In a demonstration example, the warpage value of the chemically strengthened glass with a specification of 245*85*0.7 mm can be less than or equal to 0.38 mm.

[0079] Fourthly, the embodiments of the present application provide a method for preparing chemically strengthened glass. The method for preparing the chemically strengthened glass in the embodiments of the present application includes the following steps:

[0080] Step S10: Perform chemical strengthening treatment on the modified plain glass to obtain chemically strengthened glass; wherein, the modified plain glass is the modified plain glass in the above text.

[0081] Based on the small difference in the β-OH values between the air surface layer and the tin surface layer of the modified plain glass in the above text, the difference in the influence of β-OH on the air surface layer and the tin surface layer after the modified plain glass undergoes chemical strengthening treatment is small, and further, the stress difference between the air surface layer and the tin surface layer in the obtained chemically strengthened glass is small, and the warpage value of the chemically strengthened glass is low.

[0082] In some embodiments, the chemical strengthening treatment may include the following steps:

[0083] Step A1: Immerse the modified plain glass in a potassium-containing molten salt for salt bath treatment to obtain chemically strengthened glass.

[0084] In a further embodiment, the potassium-containing molten salt in step A1 can be 100% potassium nitrate molten salt. The temperature of the salt bath treatment can be 380 - 500 °C, optionally 400 - 500 °C, 380 - 450 °C; the time of the salt bath treatment can be 2 - 8 h, optionally 2 - 6 h, 3 - 8 h, 4 - 8 h. In the demonstration example, the temperature of the salt bath treatment can be typical but non-limiting temperatures such as 380 °C, 390 °C, 400 °C, 410 °C, 420 °C, 430 °C, 440 °C, 450 °C, 460 °C, 470 °C, 480 °C, 490 °C, 500 °C, or any temperature between any two numerical ranges; the time of the salt bath treatment can be typical but non-limiting times such as 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, or any time between any two numerical ranges. The chemically strengthened glass is prepared by performing a single salt bath treatment on the modified plain glass. The preparation process has few steps, the condition parameters are easy to control, and the repeatability of the preparation method is good. By controlling the time and temperature of the salt bath treatment within this range, the rate and depth of ion exchange are further increased, thereby further improving the strength, scratch resistance, and impact resistance of the prepared chemically strengthened glass.

[0085] In some embodiments, the chemical strengthening treatment may further include the following steps:

[0086] Step B1: Place the modified plain glass in a first molten salt for a first salt bath treatment to obtain a pre-strengthened glass, wherein the first molten salt contains sodium salt;

[0087] Step B2: Place the pre-strengthened glass in a second molten salt for a second salt bath treatment to obtain a chemically strengthened glass, wherein the second molten salt contains potassium salt.

[0088] The chemically strengthened glass is prepared by successively performing two salt bath treatments on the modified plain glass, namely the first salt bath treatment and the second salt bath treatment, further increasing the ion exchange depth and surface compressive stress on both sides of the chemically strengthened glass, and improving the properties such as the strength of the chemically strengthened glass.

[0089] In some embodiments, the sodium salt in the first molten salt may include sodium nitrate. The mass content of the sodium salt in the first solution can be ≥ 35%, optionally ≥ 45%. In the demonstration example, the content of the sodium salt in the first molten salt can be typical but non-limiting amounts such as 35%, 40%, 45%, 50%, 55%, 60%, or any amount between any two numerical ranges.

[0090] In some embodiments, the temperature of the first salt bath treatment can be 370 - 430°C, optionally 380 - 430°C, 400 - 430°C; the time of the first salt bath treatment can be 10 - 300 min, optionally 30 - 300 min, 10 - 200 min, 10 - 100 min. In exemplary embodiments, the temperature of the first salt bath treatment can be typical but non-limiting values such as 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, etc., or any value between two numerical ranges; the time of the first salt bath treatment can be typical but non-limiting times such as 30 min, 50 min, 60 min, 90 min, 120 min, 150 min, 180 min, 200 min, 250 min, 300 min, etc., or any time between two numerical ranges. Controlling the content of sodium salt in the first molten salt within this range, as well as the temperature and time of the first salt bath treatment within this range, further promotes the exchange between small-volume ions such as lithium ions and sodium ions in the modified soda-lime glass, and increases the exchange depth of sodium ions.

[0091] In some embodiments, the potassium salt in the second molten salt can include potassium nitrate. The mass content of potassium nitrate in the second molten salt can be ≥90%, optionally 92% - 100%, 92% - 98%. In exemplary embodiments, the mass content of potassium nitrate in the second molten salt can be typical but non-limiting values such as 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc., or any value between two numerical ranges.

[0092] In some embodiments, the temperature of the second salt bath treatment can be 370 - 460°C, optionally 380 - 450°C, 400 - 460°C; the time of the second salt bath treatment can be 10 - 300 min, optionally 30 - 300 min, 10 - 200 min, 10 - 100 min. In exemplary embodiments, the temperature of the second salt bath treatment can be typical but non-limiting values such as 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, etc., or any value between two numerical ranges; the time of the second salt bath treatment can be typical but non-limiting times such as 10 min, 30 min, 50 min, 60 min, 90 min, 120 min, 150 min, 180 min, 200 min, 250 min, 300 min, etc., or any time between two numerical ranges. Controlling the content of potassium salt in the second molten salt within this range, as well as the temperature and time of the second salt bath treatment within this range, further promotes the exchange between relatively small-volume ions such as sodium ions and potassium ions in the pre-strengthened glass, increases the exchange depth of potassium ions, and increases the stress and strength on both sides of the chemically strengthened glass.

[0093] Fifth aspect, embodiments of the present application provide a cover glass. The cover glass in the embodiments of the present application is made from the chemically strengthened glass described above.

[0094] Based on the low warpage value of the chemically strengthened glass described above, the cover glass in the embodiments of the present application has a low warpage value and good flatness. As a result, the cover glass in the embodiments of the present application can better closely fit with other components of the electronic device, improve the yield rate during the production of the electronic device, reduce the production cost, enhance the response speed and display quality of the touch screen, and enhance the user experience.

[0095] Sixth aspect, embodiments of the present application provide an electronic device. The electronic device in the embodiments of the present application includes the cover glass described above.

[0096] Due to the low warpage value and high strength of the cover glass described above, the touch screen of the electronic device in the embodiments of the present application has a fast response speed, high display quality, and good user experience.

[0097] To enable those skilled in the art to clearly understand the above implementation details and operations of the present application, and to significantly demonstrate the improved performance of the modified plain glass and its preparation method and application in the embodiments of the present application, the following technical solutions will be illustrated by multiple embodiments.

[0098] 1. Modified plain glass and its preparation method

[0099] Example A1

[0100] This example provides modified plain glass. The modified plain glass in this example includes an air layer and a tin layer, and both the air layer and the tin layer contain β-OH.

[0101] The preparation method of the modified plain glass in this example includes the following steps:

[0102] Step S1: Provide plain glass prepared by the float method with dimensions of 245 * 85 * 0.7 mm. The components of the plain glass in this example are as follows:

[0103]

[0104]

[0105] Step S2: Modify the air surface of the plain glass. Immerse the air surface of the plain glass in the modification solution, heat it to 85 °C, keep it warm for 2 h, then cool it to room temperature and wash it to obtain the modified plain glass in this example. The modification solution is a 5% hydrogen peroxide solution.

[0106] Examples A2 to A8

[0107] Examples A2 to A8 each provide a modified plain glass. Examples A2 to A8 are substantially the same as the modified plain glass and its preparation method of Example A2, except that: the modification solutions and treatment conditions during the modification treatment of the modified plain glass in Examples A2 to A8 are shown in Table 1.

[0108] Comparative Example A1

[0109] This comparative example provides a plain glass, which is the same as the plain glass without modification treatment in Example A1.

[0110] 2. Parameter testing of the modified plain glass

[0111] Take the modified plain glass of Examples A1 to A8 above, and the plain glass without modification treatment in Example A1, and measure the β-OH values of their air surface layer and tin surface layer, as well as the sodium contents of the tin surface layer and air surface layer. The results are shown in Table 1.

[0112] Table 1

[0113]

[0114]

[0115] 3. Chemically strengthened glass and its preparation method

[0116] Example B1

[0117] This example provides a chemically strengthened glass, which is prepared by chemically strengthening the modified plain glass of Example A1.

[0118] The preparation method of the chemically strengthened glass in this example includes the following steps:

[0119] Step G1: Chemically strengthen the modified plain glass of Example A1 in 100% potassium nitrate molten salt, with the strengthening temperature being 450 °C and the strengthening time being 4 hours.

[0120] Examples B2 to B8

[0121] Examples B2 to B8 each provide a chemically strengthened glass. The chemically strengthened glasses of Examples B2 to B8 are respectively prepared by chemically strengthening the modified plain glasses of Examples A2 to A8. Among them, the chemically strengthened glass of Example B2 is prepared by chemically strengthening the modified plain glass of Example A2, the chemically strengthened glass of Example B3 is prepared by chemically strengthening the modified plain glass of Example A3, and so on. The chemically strengthened glass of Example B8 is prepared by chemically strengthening the modified plain glass of Example A8.

[0122] The chemical strengthening treatment methods for the chemically strengthened glasses of Examples B2 to B8 are the same as those for the chemically strengthened glass of Example B1.

[0123] Comparative Example B1

[0124] Comparative Example B1 provides a chemically strengthened glass, which is prepared by chemically strengthening the plain glass without modification treatment in the modification of Example A1. The chemical strengthening treatment method for the chemically strengthened glass of this comparative example is the same as that for the chemically strengthened glass of Example B1.

[0125] Warpage value measurement:

[0126] Take the chemically strengthened glasses of the above Examples B1 to B8 and Comparative Example B1, and measure their warpage values. The results are shown in Table 2.

[0127] Table 2

[0128] Chemically strengthened glass Warpage value after strengthening / mm Example B1 0.204 Example B2 0.223 Example B3 0.264 Example B4 0.232 Example B5 0.162 Example B6 0.179 Example B7 0.173 Example B8 0.166 Comparative example B1 0.352

[0129] As shown in Table 2, compared with the chemically strengthened glass of Comparative Example B1, the warpage values of the chemically strengthened glasses of Examples B1 to B8 are significantly reduced. This shows that by modifying the plain glass through the method for preparing the modified plain glass in the embodiments of the present application, the stress difference between the air layer and the tin layer after the ion exchange treatment of the modified plain glass can be effectively reduced, thereby effectively reducing the warpage of the chemically strengthened glass.

[0130] In addition, as can be seen from Table 2, the warpage values of the chemically strengthened glasses of Examples B5 and B6 are significantly lower than those of the chemically strengthened glass of Example B1. This shows that within a certain range, increasing the concentration of hydrogen peroxide in the modification solution can further promote the formation of β-OH in the air layer, thereby further reducing the β-OH value difference between the air layer and the tin layer, and thus reducing the warpage value of the chemically strengthened glass.

[0131] By comparing the warpage values of the chemically strengthened glasses of Examples B7 and B8 with those of Example B1, it can be seen that by adding an appropriate amount of inorganic acid such as hydrochloric acid to the modification solution, the stress difference between the air layer and the tin layer of the modified plain glass after chemical strengthening can be further reduced, thereby further reducing the warpage of the chemically strengthened glass.

[0132] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A modified plain glass, characterized in that: It includes an air surface layer and a tin surface layer, wherein both the air surface layer and the tin surface layer contain β-OH, and the difference between the β-OH value in the tin surface layer and the β-OH value in the air surface layer is ≤0.04 mm -1 .

2. The modified plain glass according to claim 1, characterized in that: The depth of the air surface layer and the tin surface layer is within the range of 0 to 10 μm, and the difference in sodium content between the tin surface layer and the air surface layer is 0.4% to 0.8%; and / or The M value of the plain glass is 0 to 0.25, wherein the M value is |0.6*(β-OH value of tin surface layer / β-OH value of air surface layer)-0.4*(Na content of tin surface layer / Na content of air surface layer)|.

3. The modified plain glass according to any one of claims 1 to 2, characterized in that: The thickness of the modified plain glass is 0.1 to 2 mm; The modified plain glass comprises the following components by mass percentage: or 4. The method for preparing the modified plain glass according to any one of claims 1 to 3, characterized in that: The steps include: The air surface of the plain glass is placed in a modification solution for modification to obtain a modified plain glass; Wherein, the modified solution contains hydrogen peroxide.

5. The preparation method according to claim 4, characterized in that: The concentration of hydrogen peroxide in the modified solution is 3% to 30%; and / or The modified solution further contains an inorganic acid, and the concentration of the inorganic acid in the modified solution is 1% to 5%; and / or The temperature of the modification treatment is 20 to 85° C.; and / or the time of the modification treatment is 0.5 to 4 hours.

6. A chemically strengthened glass, characterized in that: The chemically strengthened glass is obtained by chemically strengthening modified plain glass, wherein the modified plain glass is the modified plain glass described in any one of claims 1 to 3 or the modified plain glass obtained by the modified plain glass preparation method described in any one of claims 4 to 5.

7. The chemically strengthened glass according to claim 6, wherein: The warpage value of the chemically strengthened glass is less than or equal to 0.38 mm.

8. The method for preparing chemically strengthened glass according to any one of claims 6 to 7, characterized in that: The steps include: Performing chemical strengthening treatment on the modified plain glass to obtain chemically strengthened glass; Wherein, the modified plain glass is the modified plain glass described in any one of claims 1 to 3 or the modified plain glass prepared by the modified plain glass preparation method described in any one of claims 4 to 5.

9. A cover glass, characterized in that: The invention comprises the chemically strengthened glass according to any one of claims 6 to 7 or the chemically strengthened glass prepared by the method for preparing chemically strengthened glass according to claim 8.

10. An electronic device, characterized in that: Comprising the cover glass as claimed in claim 9.

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