CN118702406A - Protective glass and preparation method thereof - Google Patents

Abstract

The application provides protective glass and a preparation method thereof, and relates to the field of glass. The protective glass comprises ：58-66wt％SiO₂,18-24wt％Al₂O₃,0.2-2.5wt％K₂O,0.5-10wt％Na₂O,0.1-5wt％Li₂O,0.3-4wt％ZrO₂,0.05-4wt％B₂O₃,0-3wt％MgO,0-5wt％Y₂O₃; of the following components and satisfies 0.1 < (Y ₂O₃+B₂O₃)/Al₂O₃ is less than 0.4. The highest density of the protective glass can reach 2.65g/cm < 3 >, the internal structure of the glass is compact, the protective glass has excellent mechanical properties, and the protective glass meets the ultra-thin and high-strength performance requirements of the market.

Description

Protective glass and preparation method thereof

Technical Field

The present application relates to the field of glass, and in particular, to a protective glass and a method for preparing the same.

Background Art

In the field of modern science and technology, protective glass is widely used in consumer electronics, automotive, industrial control, and display. The main function of protective glass is to protect the equipment from external physical impact and chemical corrosion. In the field of display protection, due to the lightweight and large size of smart devices, higher requirements are placed on protective glass, which needs to have ultra-thin and high-strength properties.

In reality, the actual strength of glass is less than one percent of its theoretical strength. This is mainly because glass is a brittle material and will produce many tiny cracks (especially surface microcracks) that are invisible to the naked eye during the production process. These microcracks spread to the surroundings or the inside when affected by external forces, causing the glass to break and fail.

Therefore, improving the strength of glass is an issue that needs to be improved.

Summary of the invention

The purpose of the embodiments of the present application is to provide a protective glass and a method for preparing the same, which is intended to improve the strength of the glass.

The present application provides a technical solution.

A protective glass comprising _the following components: 58-66wt% _SiO2 , 18-24wt% Al2O3, 0.2-2.5wt% _K2O , 0.5-10wt% _Na2O , 0.1-5wt% _Li2O , 0.3-4wt% _{ZrO2 ,} 0.05-4wt% _B2O3 , _0-3wt % _MgO , 0-5wt% _Y2O3 ; and satisfying 0.1 _{＜(Y2O3 +B2O3 ) / Al2O3 ＜} 0.4.

In other embodiments of the present application, the proportions of the components of the protective glass satisfy the following formula:

In the illustration, R ₂ O=Li ₂ O+Na ₂ O+K ₂ O.

In other embodiments of the present application, the protective glass may further include:

0.1-2.5wt% ZnO.

In other embodiments of the present application, the protective glass has the following properties:

Density ρ ≥ 2.50 g/cm ³ ;

Diamond scratch greater than or equal to 8N;

The flexural strength is greater than or equal to 3500MPa.

In other embodiments of the present application, the protective glass has the following properties:

CS80≥40Mpa.

In other embodiments of the present application, the protective glass has the following properties:

Young's modulus is greater than or equal to 84 GPa;

Vickers hardness is greater than 680HV.

In other embodiments of the present application, the protective glass has the following properties:

The microcrack growth rate is less than 3.5.

In other embodiments of the present application, the protective glass has the following properties:

The surface scratch threshold of diamond scratch is greater than or equal to 8N.

The present application also provides a method for preparing the above-mentioned protective glass. The method for preparing the protective glass comprises:

A first ion bath treatment is performed in a molten salt comprising NaNO ₃ and KNO ₃ , wherein 50wt%≤NaNO _3≤65wt % of the molten salt; the temperature of the first ion bath is 420°C-470°C;

A second ion bath treatment is carried out in a molten salt comprising NaNO ₃ and KNO ₃ , wherein 1wt%≤NaNO _3≤5wt % in the molten salt, and the temperature of the second ion bath is 410°C-430°C.

In other embodiments of the present application, it is determined that the glass reconstruction stress after the second ion bath treatment is <850 MPa;

The second ion bath treatment also includes:

A third ion bath treatment is carried out in a molten salt including KNO ₃ , wherein the Na ⁺ concentration in the molten salt is less than 1000 ppm, and the Li ⁺ concentration is less than 200 ppm; the temperature of the third ion bath is 400°C-420°C.

In other embodiments of the present application, after the first ion bath treatment and before the second ion bath treatment, the method further includes:

Soak in a _KNO3 salt bath with a Na ⁺ concentration > 20000ppm.

The protective glass and the preparation method thereof provided in the embodiments of the present application have the following beneficial effects:

1. The density can reach up to 2.65g/cm3, and the internal structure of the glass is relatively dense, which makes it have excellent mechanical properties and meet the market's ultra-thin and high-strength performance requirements;

2. The internal structure is relatively dense, which makes the micro-cracks in the glass expand at a lower speed, greatly reducing the failure caused by the spread of micro-cracks;

3. Low molding threshold temperature, convenient for industrial production and energy saving;

4. The special ion bath treatment technology is simple and efficient, with higher compressive reconstruction stress perpendicular to the glass surface, which can effectively prevent the spread of microcracks and prevent rupture and failure;

5. Ultra-high surface hardness and bending strength can effectively prevent scratches in daily use scenarios that affect user experience.

The protective glass of the present invention has higher hardness and better puncture resistance, and can effectively prevent damage to the screen by sharp objects. At the same time, due to the use of unique ion bath treatment technology, the production cost of the glass is relatively low, it is easy to achieve large-scale production, and has good market competitiveness.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

Figure 1 is a diagram of the foreign body penetration failure height test equipment.

FIG. 2 is a structural diagram of protective glass that has failed due to puncture by a foreign object.

FIG3 is a structural diagram of the buffer foam in the foreign body puncture failure test.

Figure 4 is a diagram of a jig that fails due to foreign body penetration.

DETAILED DESCRIPTION

In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

According to Griffith's crack growth theory, microcracks of different sizes in glass require different stresses to cause them to expand. For example, when an elliptical microcrack with a major axis length of 2d is subjected to a tensile stress perpendicular to the microcrack, the ultimate strength of the glass is Where: E is the elastic modulus; σ is the surface tensile stress; μ is the Poisson's ratio. If the microcracks and tensile stress are not perpendicular to each other, and there is an arbitrary angle θ between them, the ultimate strength is The distribution of microcracks inside glass is a complex situation. If the crack length is less than the critical microcrack length for glass breakage, the glass has not completely failed and can continue to be used; if the crack length is close to or greater than the critical microcrack length, the glass will break and fail. The expansion speed of microcracks is: In the formula: k is the coefficient, which is 0.6-0.7 for lithium aluminum silicate glass; E is the elastic modulus; ρ is the glass density. It can be seen that glass microcracks are related to the glass elastic modulus, density and Poisson's ratio.

Improving the strength of glass is a problem that needs to be improved in the embodiments of the present application.

The protective glass and its preparation method according to the embodiment of the present application are described in detail below.

The embodiment of the present application provides a protective glass, comprising the following components: _58-66wt % _SiO2 , 18-24wt% _Al2O3 , _0.2-2.5wt % _K2O , 0.5-10wt% _Na2O , 0.1-5wt% Li2O, 0.3-4wt% _{ZrO2 ,} 0.05-4wt% _B2O3 , 0-3wt% MgO, 0-5wt% _{Y2O3 , and} satisfying 0.1＜ _{( Y2O3} + _{B2O3 )} / _Al2O3 ＜0.4.

"wt%" means percent by mass.

58-66wt% SiO ₂ is used as the basic material to ensure the basic structure and light transmittance of the glass, 18-24wt% Al ₂ O ₃ is added to improve the hardness and wear resistance of the glass, 0-2.5wt% K ₂ O, 0-10wt% Na ₂ O, 0-5wt% Li ₂ O are introduced to optimize the glass network structure and enhance its chemical stability and durability, and 0-4wt% ZrO ₂ , 0-4wt% B ₂ O ₃ , 0-3wt% MgO, 0-3wt% ZnO, 0-5wt% Y ₂ O ₃ and other intermediate oxides and network modifiers are introduced to further improve the comprehensive performance of the glass. The high-density ion-bath-treatable screen protection glass obtained by using the above components obtains a layer of dense compressive reconstruction stress after a special ion bath treatment, thereby greatly improving its hardness and resistance to foreign body puncture.

In some embodiments, the protective glass comprises _the following composition: 58-64wt% _SiO2 , 18-24wt% _{Al2O3 ,} 7-13wt% _R2O , 1-3.5wt% ZrO2, 0-3wt% _B2O3 , 0-3wt% _MgO , _0-2.5wt % ZnO, 0-5wt% _Y2O3 ; wherein _R2O ＝ _Li2O + _Na2O + _K2O , and satisfies

_SiO2 is a key component in the glass manufacturing process. It is mainly responsible for forming a stable network structure of glass, giving glass its transparency and hardness. In glass, the right amount of silica content can ensure good chemical resistance, thermal stability and mechanical strength, and is therefore crucial to the final performance of the product. However, when the silica content is too high, although it can further improve the heat resistance and corrosion resistance of the glass, it will also increase the melting temperature, increase energy consumption, and may cause accelerated wear of equipment in production. Relatively speaking, if the silica content is too low, it may reduce the weather resistance and mechanical strength of the glass, affect the service life and application range of the product, and fogging may occur during post-processing, affecting the post-process yield. Therefore, in order to balance cost, production efficiency and the physical and chemical properties of the product, it is very important to control the silica content in the glass within an optimized range. Such control not only ensures the stability of glass quality, but also enables the product to meet the needs of different application scenarios. Exemplarily, the proportion of SiO ₂ in the protective glass can be 58 wt %, 59 wt %, 60 wt %, 62 wt %, 63 wt %, 64 wt %, 65 wt % or 66 wt %, etc.

As an intermediate _oxide , _Al2O3 can significantly improve the chemical stability of glass, making it more resistant to chemical corrosion. It also helps to reduce the crystallization tendency and speed of glass, which is conducive to maintaining the amorphous state of glass. The increase in the content of aluminum oxide will increase the hardness and impact resistance of glass and enhance its mechanical strength, which is particularly important for protective glass products. At the same time, aluminum oxide can effectively reduce the thermal expansion coefficient of glass, thereby improving the thermal stability of glass. Since aluminum oxide increases the viscosity of glass liquid, it is not conducive to the flattening and polishing of glass during the molding process, but an appropriate amount of aluminum oxide can ensure that the glass has the necessary fluidity and plasticity during molding. Although aluminum oxide plays a very important role in glass, its usage ratio still needs to be controlled within a certain range. Too high alumina content will increase the melting point of glass, resulting in difficulty in melting and increased energy consumption, and may also affect other properties of glass, such as light transmittance and color. Therefore, it is crucial to reasonably control the proportion of aluminum oxide in glass according to different application requirements and production processes.

For example, the proportion of Al ₂ O ₃ in the protective glass may be 18 wt %, 19 wt %, 20 wt %, 21 wt %, 22 wt %, 23 wt % or 24 wt %, etc.

As an extracellular oxide, _R2O alkali metal plays an important role in the performance of glass. It can lower the melting point of glass, making it easier to melt into liquid state, which is beneficial to the preparation and molding of glass. Alkali metal has a certain influence on the physical and chemical properties of glass, and can adjust the refractive index, thermal expansion coefficient, chemical stability and other properties of glass. _R2O includes _K2O , _Na2O and _Li2O .

Illustratively, the proportion of K ₂ O in the protective glass may be 0.2 wt %, 0.3 wt %, 0.5 wt %, 0.8 wt %, 1 wt %, 1.2 wt %, 1.5 wt %, 1.8 wt %, 2 wt %, 2.5 wt %, and the like.

Illustratively, the proportion of Na ₂ O in the protective glass may be 0.2 wt %, 1 wt %, 2 wt %, 3 wt %, 4 wt %, 5 wt %, 6 wt %, 7 wt %, 8 wt %, 10 wt %, and the like.

Illustratively, the proportion of Li ₂ O in the protective glass may be 0.2 wt %, 0.8 wt %, 1 wt %, 1.5 wt %, 2 wt %, 2.5 wt %, 3 wt %, 3.5 wt %, 4 wt %, 5 wt %, and the like.

The role of _ZrO2 in glass is mainly as a network modifier. It can form strong bonds with non-bridging oxygen in the silicon-oxygen network, thereby increasing the connectivity and stability of the glass network. This effect helps to improve the chemical durability and mechanical strength of the glass. At the same time, due to the high refractive index of zirconium oxide, it can also be used to adjust the optical properties of glass. However, too high a _ZrO2 content will increase the melting temperature of the glass and increase energy consumption, so it needs to be controlled within a certain range.

Exemplarily, the proportion of _ZrO2 in the protective glass can be 0.2wt%, 0.8wt%, 1wt%, 1.6wt%, 2.1wt%, 2.6wt%, 3wt%, 3.4wt%, 3.6wt%, 4wt%, etc.

B ₂ O ₃ can act as a network former, which can connect with silicon-oxygen tetrahedrons [SiO ₄ ] at the same angle to form a more complex three-dimensional network structure, which increases the stability and chemical resistance of the glass.

At the same time, the addition of boron oxide will change the structure of some silicon-oxygen tetrahedrons, resulting in the appearance of boron-oxygen triangular pyramid structures or boron-oxygen tetrahedron structures in the glass network. These structures have higher mobility than silicon-oxygen tetrahedrons, which can reduce the viscosity of the glass and facilitate molding. However, excessive boron oxide can cause some problems. Too much boron oxide can soften the glass excessively and affect its mechanical strength. High levels of boron oxide may cause crystallization problems, thereby affecting the transparency and uniformity of the glass. During the manufacturing process, excessive boron oxide content may increase raw material costs and cause erosion to refractory materials. Therefore, according to different application requirements and production processes, the amount of boron oxide added to the glass usually needs to be carefully optimized to ensure that the final product has the expected performance and quality.

Illustratively, the proportion of B ₂ O ₃ in the protective glass may be 0.2 wt %, 0.8 wt %, 1 wt %, 1.6 wt %, 2.1 wt %, 2.6 wt %, 3 wt %, 3.4 wt %, 3.6 wt %, 4 wt %, etc.

As a network modifier, MgO can change the amount of non-bridging oxygen in the glass network structure, enhance the elasticity of the glass, and thus improve its wear resistance and chemical corrosion resistance. It can also adjust the viscosity and surface tension of the glass, lower the melting point of the glass, and facilitate molding. Excessive magnesium oxide content will not only affect the melting and molding process of the glass, but may also cause crystallization and chemical stability problems.

Exemplarily, the proportion of MgO in the protective glass can be 0.2wt%, 0.5wt%, 0.8wt%, 1wt%, 1.3wt%, 1.5wt%, 2wt%, 2.4wt%, 2.6wt%, 2.8wt%, 3wt%, etc.

As a network modifier, ZnO can provide free oxygen. These oxygen ions can form non-bridging oxygen with silicon ions in the silicon-oxygen network, thereby changing the original network structure, lowering the melting point and adjusting the thermal expansion coefficient. In addition, since zinc oxide has a small ion radius, it replaces other ions in the glass network (such as sodium, calcium, etc.), which can optimize the glass network space, making the glass easier to melt and process, and can effectively improve the stripes produced during the glass production process. However, the zinc oxide content needs to be controlled within a certain range. Too much zinc oxide may cause the glass to become unstable and prone to devitrification.

Exemplarily, the proportion of ZnO in the protective glass can be 0.2wt%, 0.5wt%, 0.8wt%, 1wt%, 1.3wt%, 1.5wt%, 2wt%, 2.4wt%, 2.5wt%, etc.

As a network modifier, _Y2O3 can form strong bonds with the bridging oxygen and non-bridging oxygen in the silicon-oxygen network. Since _yttrium has a high coordination number, its addition often increases the degree of cross-linking of the glass structure, thereby improving the stability and chemical corrosion resistance of the glass. In addition, yttrium trioxide has a large molecular weight, so its introduction will also moderately increase the density of the glass, making the glass denser and thicker. However, the content of yttrium trioxide needs to be carefully controlled. Too high a proportion may cause the glass to become opaque (devitrification) and affect its transparency. At the same time, too much yttrium trioxide may also cause the glass to become foggy during the post-process citric acid cleaning process.

For example, the proportion of _Y2O3 in the protective glass can be 0.2wt%, 0.8wt%, 1wt%, 1.5wt%, 2wt%, 2.6wt%, 2.8wt%, 3wt%, _3.4wt %, 3.8wt%, 5wt%, etc.

Furthermore, the proportions of Y ₂ O ₃ , B ₂ O ₃ , and Al ₂ O ₃ in the protective glass satisfy the following relationship:

0.1<(Y ₂ O ₃ +B ₂ O ₃ )/Al ₂ O ₃ <0.4.

In some embodiments, the ratio of components of the protective glass satisfies the following formula:

In the illustration, R ₂ O=Li ₂ O+Na ₂ O+K ₂ O.

In an embodiment of the present application, the density of the protective glass is ρ≥2.50 g/cm ³ .

For light with a wavelength of 550nm, the light transmittance of the protective glass is ≥92.0%.

The shaping threshold of protective glass is less than 1150℃. The aforementioned shaping threshold is the characteristic temperature corresponding to the glass viscosity of 10 ^4.0 dPa·s. The test is conducted by the rotational viscometer method in accordance with the national standard GB/T42414-2023 "Determination of Glass Viscosity". The test equipment is a high temperature viscometer, model RSV-16RT.

The softening threshold of protective glass is less than 800°C. The softening threshold is the characteristic temperature corresponding to the glass viscosity of 10 ^7.65 dPa·s. The test is carried out in accordance with the national standard GB_T 28195-2011 "Test method for softening point of glass", and the test equipment is a softening point tester, model SP-1100A.

The thermal stabilization threshold of the protective glass is less than 580°C. The thermal stabilization threshold is the characteristic temperature corresponding to a glass viscosity of 10 ^13.0 dPa·s. The test is carried out in accordance with GB/T 28196-2011 "Test Method for Annealing Point and Strain Point of Glass", and the test equipment is an annealing point tester, model ANS-800.

The bending strength of the protective glass is greater than 3500MPa.

The diamond scratch threshold of the protective glass is greater than or equal to 8N. The test method for the surface scratch threshold is in accordance with GB/T 39815-2021 "Test method for scratch resistance of ultra-thin glass".

The protective glass does not become hazy or blue after being cleaned with 5wt% citric acid at 70°C for 5 minutes.

The Young's modulus of the protective glass is greater than or equal to 84 GPa.

The Vickers hardness of protective glass is greater than 680HV. The test is carried out in accordance with the national standard GB/T 37900-2019 "Test method for hardness and fracture toughness of ultra-thin glass - small load Vickers hardness indentation method", and the test equipment is an automatic microhardness tester, model HVS-1000AT2.1.

The microcrack growth rate of protective glass is less than 3.5.

The compressive reconstruction stress is ≥40MPa at 80μm in the direction perpendicular to the glass surface, that is, CS80 ≥40MPa.

A compressive reconstructed stress layer of more than 100 μm perpendicular to the glass surface. The compressive reconstructed stress layer is the depth of the stress layer obtained by ion exchange.

The puncture resistance failure height can reach over 180cm.

Among them, the foreign body puncture failure height test equipment is shown in Figure 1. The test sample is clamped by the fixture, raised to the set height, and then performs free fall motion. When it is 200mm close to the drop table, the clamping device is released to ensure that the protective glass is in surface contact with the drop table. The test conditions are glass + fixture = 200g, base height 50cm, 10cm/height increment, until the protective glass breaks. The protective glass and the fixture are glued together by cushioning foam and double-sided tape.

In Figure 1, 1-safety frame, 2-safety light curtain, 3-control panel, 4-clamp, 5-drop table, 6-machine pulley.

The dimensions of the protective glass that failed due to foreign body puncture are shown in Figure 2. The units in Figure 2 are all mm.

FIG3 is a foreign body puncture failure test of the cushioning foam. The units in FIG3 are all mm.

Figure 4 is a foreign body puncture failure test fixture. The units in Figure 4 are all mm. The test fixture in Figure 4 is 304 stainless steel, and the flatness requirement is less than 0.2mm, the warping is less than 0.2mm, and the surface needs to be polished smooth to avoid puncture and scratches on the glass. In addition, the length, width and thickness of 304 stainless steel are 160mm, 77mm, and 2.0mm respectively. The long and wide sides are chamfered, and the radius of the chamfer is 6.45mm.

During the foreign body piercing process, the 304 stainless steel shown in FIG. 4 , the foam shown in FIG. 3 , and the protective glass shown in FIG. 2 are stacked to form the test sample described in FIG. 1 above; the foam is located between the 304 stainless steel and the foam.

The present application also provides a method for preparing the protective glass. The method for preparing the protective glass comprises:

The first ion bath treatment is carried out in a molten salt comprising NaNO ₃ and KNO ₃ , wherein 50wt%≤NaNO _3≤65wt % of the molten salt; and the temperature of the first ion bath is 420°C-470°C.

For example, the content of NaNO ₃ in the molten salt treated by the first ion bath can be 50wt%, 53wt%, 55wt%, 58wt%, 60wt%, 62wt% or 65wt%, etc. The temperature of the first ion bath can be, for example, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, etc.

A second ion bath treatment is carried out in a molten salt comprising NaNO ₃ and KNO ₃ , wherein 1wt%≤NaNO _3≤5wt % in the molten salt, and the temperature of the second ion bath is 410°C-430°C.

For example, the content of NaNO ₃ in the molten salt treated by the second ion bath can be 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, etc. The temperature of the second ion bath can be, for example, 410°C, 420°C, 430°C, etc.

In some embodiments, the protective glass may be kept at 360-390° C. for 30-60 minutes before the second ion bath treatment to avoid glass cracks.

In some embodiments, after the second ion bath treatment, the surface stress meter FSM-6000LE can be used to detect the glass reconstruction stress. If the protective glass reconstruction stress obtained after the second ion bath treatment is ≥850MPa, the third ion bath treatment is not required.

If it is determined that the glass reconstruction stress after the second ion bath treatment is less than 850Mpa, then the second ion bath treatment also includes:

A third ion bath treatment is carried out in a molten salt including KNO ₃ , wherein the Na ⁺ concentration in the molten salt is less than 1000 ppm, and the Li ⁺ concentration is less than 200 ppm; the temperature of the third ion bath is 400°C-420°C.

In some embodiments, the Na ⁺ concentration and the Li ⁺ concentration in the third ion bath treatment are both relatively small. The temperature of the third ion bath treatment may be, for example, 400° C., 410° C., 420° C., etc. The third ion bath treatment is beneficial to improving the reconstruction stress of the protective glass.

In some embodiments, after the first ion bath treatment and before the second ion bath treatment, the method further includes:

Soak in a _KNO3 salt bath with a Na ⁺ concentration > 20000ppm.

The features and performance of the present application are further described in detail below in conjunction with the embodiments.

Example 1-Example 8

Examples 1 to 8 provide protective glass having the components shown in Table 1.

The preparation methods of Examples 1 to 8 are as follows:

After the raw materials are mixed evenly, they are melted into glass liquid at high temperature, and then formed into a glass plate after annealing and cooling.

Then, the glass plate is cut. Exemplarily, the length, width and thickness of the glass plate are 158 mm, 75 mm and 0.6 mm respectively.

An ion bath was performed, and the conditions of the ion bath were as shown in Table 3.

The protective glass obtained after the ion bath was tested, and the test results are shown in Table 2 and Table 3. The test items in Table 2 were performed before the first ion bath.

The conditions of the ion bath components and the test results of Comparative Examples 1 to 4 are shown in Table 4.

Table 1

Table 2

Table 3

Table 4

It can be seen from Table 2, Table 3 and Table 4 that, compared with Comparative Examples 1-4, the protective glass of each component shown in Examples 1-8 of the present invention has a lower modeling threshold, is convenient for industrial production, and can also reduce energy consumption; has a higher density and Young's modulus, so that it has a lower microcrack diffusion rate, effectively avoiding rupture failure; has a higher light transmittance, which can effectively improve the visual experience; has excellent weak acid resistance, does not turn hazy or blue during post-process processing and cleaning, and effectively improves the post-process yield; after being treated with a special ion bath, has a higher hardness, which is manifested as a higher surface scratch threshold, and at the same time has a higher reconstructed compressive stress and a reconstructed stress layer inside, which further effectively prevents the spread of microcracks and prevents glass rupture failure, and the puncture resistance failure height is as high as 180 cm or more.

The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. A cover glass characterized by comprising ：58-66wt％SiO₂,18-24wt％Al₂O₃,0.2-2.5wt％K₂O,0.5-10wt％Na₂O,0.1-5wt％Li₂O,0.3-4wt％ZrO₂,0.05-4wt％B₂O₃,0-3wt％MgO,0-5wt％Y₂O₃; and satisfying 0.1 < (Y ₂O₃+B₂O₃)/Al₂O₃ < 0.4.

2. The cover glass according to claim 1, wherein the ratio of the components of the cover glass satisfies the following formula:

In the illustration, R ₂O＝Li₂O+Na₂O+K₂ O.

3. The cover glass according to claim 1 or 2, wherein the cover glass may further comprise:

0.1-2.5wt％ZnO。

4. the cover glass according to claim 1, wherein the cover glass has the following properties:

the density rho is more than or equal to 2.50g/cm ³;

diamond scratches are greater than or equal to 8N;

The bending strength is 3500MPa or more.

5. The cover glass according to claim 1, wherein the cover glass has the following properties:

CS80≥40Mpa。

6. The cover glass according to claim 1, wherein the cover glass has the following properties:

young's modulus of 84GPa or more;

The Vickers hardness is more than 680HV;

the microcrack propagation rate is less than 3.5.

7. The cover glass according to claim 1, wherein the cover glass has the following properties:

And the surface scratch threshold value of the diamond scratch is more than or equal to 8N.

8. The method for producing a cover glass according to any one of claims 1 to 7, comprising:

Carrying out first ion bath treatment in molten salt containing NaNO ₃ and KNO ₃, wherein the content of NaNO ₃ in the molten salt is more than or equal to 50% and less than or equal to 65% by weight; the temperature of the first ion bath is 420-470 ℃;

And (3) carrying out a second ion bath treatment in molten salt containing NaNO ₃ and KNO ₃, wherein the weight percent of NaNO ₃ in the molten salt is more than or equal to 1 and less than or equal to 5, and the temperature of the second ion bath is 410-430 ℃.

9. The method for producing a cover glass according to claim 8, wherein,

Determining that the glass reconstruction stress is less than 850Mpa after the second ion bath treatment;

The second ion bath treatment further comprises the following steps:

performing a third ion bath treatment in a molten salt comprising KNO ₃, wherein the concentration of Na ⁺ in the molten salt is less than 1000ppm and the concentration of Li ⁺ in the molten salt is less than 200ppm; the temperature of the third ion bath is 400-420 ℃.

10. The method for producing a cover glass according to claim 8 or 9, characterized by further comprising, after the first ion bath treatment, before the second ion bath treatment:

Soaking in KNO ₃ salt bath with Na ⁺ concentration higher than 20000 ppm.