WO2022166029A1 - Aluminosilicate reinforced glass and preparation method therefor - Google Patents

Abstract

The present invention relates to an aluminosilicate reinforced glass and a preparation method therefor. For the aluminosilicate reinforced glass, aluminosilicate glass is reinforced in one step by using a mixed molten salt of NaNO₃ and KNO₃. In weight percent, the composition of the aluminosilicate glass comprises: 48%-61% SiO₂, 23%-34% Al₂O₃, 4%-7% Li₂O, 1.5%-6% Na₂O, 0.01%-3% K₂O, 1%-5% MgO, 0.4%-6% B₂O₃, 0.1%-1% Y₂O₃, wherein B₂O₃/Y₂O₃=4-5, and 0.4%-3% ZrO ₂. The aluminosilicate reinforced glass has excellent mechanical properties, can withstand rough ground drop resistance and rough surface roller tumbling tests, and has a relatively high degree of fragmentation factor γ.

Description

Aluminosilicate strengthened glass and preparation method thereof technical field

The invention relates to the technical field of glass manufacturing, in particular to an aluminosilicate reinforced glass and a preparation method thereof.

Background technique

Mobile phones have become a necessity in daily life today, tablet computers are becoming more popular, and various devices with touch screen panels are widely used in various industries. In recent years, with the development of mobile Internet 5G communication technology and wireless charging technology, more and more mobile phones have begun to use double-sided glass design. At the same time, in order to pursue differentiated and personalized design concepts such as thinness and narrow bezels, more and more mobile phones use 3D curved cover or backplane designs.

The majority of mobile phone end users are still not satisfied with the simple anti-drop performance, anti-scratch performance and anti-ball impact performance. These performance tests are often not suitable for daily use environments. For example, holding a mobile phone at a height of 1.6 meters and dropping it on rough ground; placing the mobile phone in a backpack and repeatedly hitting keys or other hard objects, etc. Therefore, mobile phone manufacturers have further proposed several special performance testing methods. For example, the whole mobile phone is dropped on the ground of sandpaper with different particle sizes, and it is repeatedly dropped until it is broken; Tumble and hit until the time to break, etc.

Compared with the drop height of the smooth ground, the drop height of the rough ground is attenuated by more than 50%. When the mobile phone cover produced by the traditional chemical strengthening process is subjected to the above-mentioned special performance tests, most of its performance results and performance stability are not satisfactory.

Examples of traditional chemical strengthening processes include:

The earliest preparation method of cover glass is to strengthen the high-alumina glass by a one-step ion exchange process. The composition range of the mainstream high-alumina glass is roughly 55% to 70% SiO ₂ , 12% to 23% Al in terms of mass percentage. ₂ O ₃ , 13%-16% Na ₂ O, 0%-5% K ₂ O, 2%-6% MgO, 0%-5% B ₂ O ₃ , 0-2% ZrO ₂ . Due to the high alumina content, its own strength is higher than that of ordinary soda lime glass, and its ion exchange capacity is also strong. The surface compressive stress (CS) generally reaches 650MPa and the depth of stress layer (DOL) is 30μm after the above-mentioned high alumina glass is ion-exchanged in pure potassium nitrate molten salt at a temperature of 390℃～450℃ for 2h～8h. On this basis, if the ion exchange time is extended to more than 8h, the depth of the stress layer can be increased to around 60μm, but it is still far from the expected value (such as more than 100μm), and the surface compressive stress value is correspondingly reduced, and it is easy to cause After strengthening, a hard-to-remove alkali-rich layer is formed on the surface of the glass, thereby forming micro-crack defects, which seriously affects the overall strength of the protective cover. Therefore, the one-step ion-exchange chemical strengthening process has a bottleneck in improving the performance of glass.

In addition, there is a method to introduce a certain amount of Li ₂ O on the basis of the above-mentioned preparation method of cover glass to prepare high-alkali (boron) aluminosilicate glass. SiO ₂ , 17%-25% Al ₂ O ₃ , 2%-4% B ₂ O ₃ , 3%-6% P ₂ O ₅ , 10%-16% Na ₂ O, 2%- 4% Li ₂ O, 0%-5% K ₂ O, 0%-5% MgO, and 0%-3% ZrO ₂ . And carry out a two-step or multi-step ion exchange chemical strengthening process for the high alkali (boron) aluminosilicate glass. By controlling the difference in the molten salt concentration in the first step and the second step, Li-Na and The ion exchange of Na-K can simultaneously obtain a higher compressive stress layer depth and an ideal surface compressive stress value. Improve the drop breaking height of the glass cover, and obtain a protective glass with better mechanical properties and mechanical impact resistance. The prior art solution involves a two-step or multi-step ion exchange chemical strengthening process, the core principle of which is that in the first step ion exchange process, Li ⁺ in the glass and Na ⁺ in the molten salt are ion-exchanged, which can The compressive stress layer is obtained within a limited time, and the depth of the stress layer is deep, so that the glass has more excellent mechanical impact resistance; in the second step ion exchange process, Na ⁺ and molten salt in the stress layer of the shallow surface of the glass are passed through. The ion exchange of medium K ⁺ can obtain a higher stress value in a short time, so that the glass has more excellent scratch resistance and microhardness. However, although the protective glass obtained by this special strengthening process can obtain excellent mechanical properties, it is necessary for mobile phone cover manufacturers to frequently adjust the process and increase the ion exchange time to more than 300min, and it is prone to pollution by different molten salts Problems, problems such as short service life of molten salt, poor process stability, low yield, high equipment investment and production costs, etc.

Another method provides an aluminosilicate glass, the composition of which, in mass percentage, is: 55%-65% SiO ₂ , 13%-26% Al ₂ O ₃ , 2%-6% Li ₂ O, 6%～11% Na ₂ O, 1%～6% K ₂ O, 0.1%～3% B ₂ O ₃ and 0.1%～4% ZrO ₂ , using NaNO ₃ and KNO ₃ mixed molten salt One-step strengthening, the ion exchange time can be shortened to 180min ~ 300min, and the one-step strengthening method is also more suitable for industrial production. At the same time, after chemical strengthening, the aluminosilicate glass can satisfy: the depth of the surface compressive stress layer can reach 75μm～181μm; the surface compressive stress value is between 650MPa～900MPa; the thickness of the aluminosilicate glass is 0.5mm in the middle The tensile stress is not higher than 80MPa; the intermediate tensile stress of the aluminosilicate glass with a thickness of 0.7mm is not higher than 60MPa.

For example, the upper cover glass does not perform well in the rough ground drop resistance and rough surface roller tumbling tests, and has a high degree of tempering. After breaking in practical applications, a large number of fine glass particles will be generated (the breaking degree factor γ is relatively small), This inevitably leads to the following problems: (1) After being broken into fine particles, dense cracks are generated. Although the corresponding shape is still maintained due to the OCA glue, a large number of broken cracks have blocked the screen display, and the mobile phone or other smart devices are The display function will be completely lost and cannot be used; (2) The fine glass particles may enter the user's eyes, mouth, etc., especially children, and will hurt the hands and other exposed body parts because the particles are too fine. Therefore, the mechanical properties of traditional cover glass need to be further improved. At the same time, although the aforementioned aluminosilicate glass also involves research on the thermal expansion coefficient, its thermal expansion coefficient at 35℃～50℃ is 73～95× ^10-7 ℃ ^-1 , and the thermal expansion coefficient at 350℃～550℃ It is 80～100×10 ^-7 ℃ ^-1 , which still needs to be further improved to better meet the temperature requirements of 3D hot bending of cover glass, and it is suitable for 3D glass with more complex structure made by 3D mold.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide an aluminosilicate strengthened glass and a preparation method thereof. The aluminosilicate tempered glass has excellent mechanical properties, can withstand the drop resistance performance of rough ground, rough surface roller tumbling test, and has a high degree of breakage factor γ.

The specific technical solutions are as follows:

In one aspect of the present invention, there is provided an aluminosilicate reinforced glass, wherein the aluminosilicate glass is strengthened by a mixed molten salt of NaNO ₃ and KNO ₃ in one step; in terms of weight percentage, the composition of the aluminosilicate glass includes: :

48%-61% SiO ₂ , 23%-34% Al ₂ O ₃ , 4%-7% Li ₂ O, 1.5%-6% Na ₂ O, 0.01%-3% K ₂ O, ₁ %-5% MgO, 0.4%-6% B2O3, 0.1% _{-1 % Y2O3} and the mass ratio _{of B2O3} and _Y2O3 is 4-5, and 0.4 _% ~ ₃ % ZrO2.

In one embodiment, the composition of the aluminosilicate glass includes:

53%-61% SiO ₂ , 23%-34% Al ₂ O ₃ , 4%-5% Li ₂ O, 1.7%-5.3% Na ₂ O, 0.2%-1.1% K ₂ O, ₁ %-5% MgO, _0.5 %-5% B2O3, 0.15% _{-1 % Y2O3} and the mass ratio _{of B2O3} and _Y2O3 is 4-5, and 0.45% ~2.8 _% ZrO2.

In one embodiment, in the composition of the aluminosilicate glass, the mass ratio of B ₂ O ₃ and Y ₂ O ₃ is 4.4-4.97.

In one of the embodiments, the composition of the aluminosilicate glass further includes P ₂ O ₅ in a weight percentage of ≤4%.

In one of the embodiments, the composition of the aluminosilicate glass further includes CaO with a content of ≤3% by weight.

In one of the embodiments, the composition of the aluminosilicate glass further includes ZnO with a content of ≤2% by weight.

Another aspect of the present invention provides the preparation method of the aluminosilicate reinforced glass, comprising the following steps:

The raw materials are mixed according to the composition of the aluminosilicate glass, and subjected to melting treatment, followed by annealing and molding to prepare the aluminosilicate glass;

The aluminosilicate glass is immersed in a mixed molten salt of NaNO ₃ and KNO ₃ for ion exchange to prepare the aluminosilicate reinforced glass.

In one embodiment, the temperature of the melting process is 1500°C to 1700°C; and/or

The temperature of the annealing is 550°C to 750°C.

In one embodiment, in terms of mass percentage, the molten salt comprises 3%-15% NaNO ₃ and 85%-97% KNO ₃ ; and/or

The temperature of the ion exchange is 400°C to 440°C; and/or

The time of the ion exchange is 120min-180min.

In yet another aspect of the present invention, there is provided a glass protective layer comprising the aluminosilicate strengthened glass as described above.

In yet another aspect of the present invention, a glass cover plate is provided, comprising the aluminosilicate tempered glass as described above.

In yet another aspect of the present invention, an electronic product is provided, using the aluminosilicate tempered glass as described above as a glass cover plate.

Compared with the prior art, the present invention has the following beneficial effects:

For the aluminosilicate reinforced glass provided by the present invention, by adjusting the composition of the aluminosilicate glass reasonably, especially introducing a certain amount of Y ₂ O ₃ , and reasonably controlling B ₂ O ₃ /Y ₂ O ₃ =4～ 5. Among them, [BO ₃ ] triangle and [BO ₄ ] tetrahedron coexist in B ₂ O ₃ in glass, and the ratio of the two directly affects the fracture toughness and broken state of glass, and [BO ₃ ] triangle does not participate The glass structure plays the role of breaking bonds, reduces the melting temperature of the glass, and hinders the expansion _of micro _- cracks when the glass is broken, so as to avoid the broken state _of the glass from being crushed. The ratio of the glass to the body, thereby optimizing the broken state of the glass in the high ion exchange state. At the same time, the spatial end network formed by B ₂ O ₃ can slide within a certain range, and when there is stress in the glass, a larger deformation can be obtained to buffer, thereby further optimizing the mechanical properties of aluminosilicate strengthened glass.

To sum up, the aluminosilicate strengthened glass provided by the present invention can have both better mechanical properties (especially high elastic modulus and high fracture toughness) than the prior art, and maintain a low expansion coefficient. After exchange, the internal tensile stress CT value is higher, the glass network structure is perfect, and the high fracture toughness can suppress the self-explosion problem in the strengthening process. Higher elastic modulus and internal tensile stress can effectively improve the rigidity of glass after strengthening, and the breakage degree factor γ is larger. When used as a protective cover for electronic products, it not only has extremely high impact resistance, but also can effectively improve the overall structural rigidity of electronic products, and can effectively restrain the deformation of the frame and protect the internal electronic components. A large number of fine glass particles will be produced, and the lower expansion coefficient can meet the temperature requirements of 3D hot bending of cover glass, and because the expansion rate is close to that of the mold, 3D glass with a more complex structure can be made through the 3D mold. in addition. The aluminosilicate glass can be strengthened in one step by using the mixed molten salt of NaNO ₃ and KNO _3. The process flow is simple, and it is easy to control the process with high precision. The strengthening time can be kept below 180min, and the processing efficiency is high.

Description of drawings

Fig. 1 is the stress test curve and basic parameters of SM6000LE and SLP1000 according to an embodiment of the present invention;

FIG. 2 is a stress test fitting curve according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of calculation of a crushing degree factor γ according to an embodiment of the present invention;

FIG. 4 is a comparison diagram of fine fragments (left) and flake fragments (right) according to an embodiment of the present invention.

Detailed ways

The aluminosilicate strengthened glass of the present invention and the preparation method thereof will be further described in detail below with reference to specific embodiments. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the present disclosure is provided.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

The invention provides an aluminosilicate reinforced glass, which adopts NaNO ₃ and KNO ₃ mixed molten salt to strengthen the aluminosilicate glass in one step; in terms of weight percentage, the composition of the aluminosilicate glass includes:

48%-61% SiO ₂ , 23%-34% Al ₂ O ₃ , 4%-7% Li ₂ O, 1.5%-6% Na ₂ O, 0.01%-3% K ₂ O, ₁ %-5% MgO, 0.4%-6% B2O3, 0.1% _-1 % _Y2O3 and _B2O3 / _{Y2O3 = 4-5} , and 0.4% _-3 % of ZrO ₂ .

The present invention can achieve the following advantages by conducting experimental research on the glass components, and optimizing the optimal combination mode and the control range of each component:

(1) The strength of the second-strength lithium-aluminosilicate glass on the market can be reached or even exceeded by one NaNO ₃ and KNO ₃ mixed molten salt tempering, which solves the problem of double tempering, complicated procedures, time-consuming and labor-intensive, and a lot of equipment investment. Problems such as low efficiency reduce production costs, and the chemical strengthening time can be shortened to within 180min;

(2) The thermal expansion coefficient of primary tempered glass is between 57～85*10 ^-6 (the thermal expansion coefficient of 3D hot bending graphite is 55～65*10 ^-7 ), which meets the temperature requirements of 3D hot bending of cover glass, and due to The expansion rate of the mold is close to that of the mold, and 3D glass with more complex structures can be made through the 3D mold;

(3) The Vickers hardness of the original glass exceeds 600Hv, which is conducive to reducing defects such as scratches and stabs caused by foreign objects in the production process. After tempering, the Vickers hardness of the glass exceeds 710Hv, which greatly improves the cover. Scratch resistance of plate glass during consumer use;

(4) Fragments of sufficient size remain after being impacted and damaged above the load;

(5) The ion exchange depth of Na-K is effectively improved, thereby forming a high-pressure stress layer with a larger thickness, which can effectively resist the micro-cracks and crack propagation left on the glass surface during the impact of rough ground, especially the ability to form The surface compressive stress layer is a composite gradient compressive stress layer. The Na-K ion exchange layer is close to the glass surface, and the Li-Na ion exchange layer is closer to the inner glass layer. When the glass thickness is 0.33mm, the glass surface compressive stress layer. The depth is still not less than 100μm, and the surface compressive stress value CSK is not less than 800MPa, and the intermediate tensile stress can be higher than 180Mpa. Due to the excellent fracture toughness of the glass itself, the thickness of the glass cover product is 0.33 ~ 0.4mm, still It has excellent anti-rough ground drop breaking performance and better stability against mechanical impact; at the same time, it has excellent ion exchange efficiency in a very short chemical strengthening time, and when the thickness of the glass changes, the stress layer distribution characteristics do not change. There will be essential changes. For example, when the glass thickness is 0.33mm, the distribution characteristics of the compressive stress layer meet the following indicators at the same time: CSNa30≥200MPa, CSNa50≥100MPa, CSK≥800MPa, DOL≥100μm, DOLK≥4.5μm. Still has excellent anti-rough ground drop crushing performance and better stability against mechanical shock;

(6) Adopt special glass chemical composition and special one-step ion exchange chemical strengthening process;

In addition, traditional methods usually use one-step ion exchange, two-step ion exchange or multi-step ion exchange for chemical strengthening treatment, and the molten salt used can be pure KNO ₃ molten salt, pure NaNO ₃ molten salt or KNO ₃ and NaNO ₃ mixed molten salt, the ratio range is between 100:0 ~ 40:60, and the optimal molten salt formula can be selected according to its glass properties. However, in the actual production process, the concentration of pure KNO ₃ molten salt, pure NaNO ₃ molten salt or mixed molten salt of KNO ₃ and NaNO ₃ will be significantly deviated after a period of use ^. If the deviation value of Li ⁺ concentration exceeds a certain range, the strengthening performance cannot be guaranteed, which will seriously affect the processing yield, and the molten salt needs to be replaced, which affects the production efficiency and increases the production cost. The technical scheme involved in the present invention adopts special glass chemical composition and one-step ion exchange chemical strengthening process, and different glass compositions can obtain the optimal mixed molten salt ratio, and the molten salt ratio for ion exchange can be in 2 The fluctuation range of CS value in its enhanced performance is within 2.5%, and the fluctuation range of DOL is within 1%. In other words, in the technical solution of the present invention, the change value of the Na ⁺ concentration of the molten salt used for ion exchange can be 20000 ppm. At the same time, the strengthening process time involved is controlled within 180 minutes, which effectively controls the ion transition exchange, greatly prolongs the service life of the molten salt, improves production efficiency and processing yield, and reduces production costs.

Further, each component in the aluminosilicate glass is described as follows:

Silicon dioxide (SiO ₂ ) is an essential component for forming the glass skeleton. SiO ₂ can improve the strength and chemical stability of the glass, and can make the glass obtain a lower thermal expansion coefficient. When the content is too low, the main network structure of the glass is poor, the mechanical properties are poor, and the weather resistance becomes poor; Chemically enhanced efficiency. At the same time, the melting temperature of glass in the production process is too high, the energy consumption increases, and it is easy to cause frequent defects such as bubbles and stones. Therefore, in the aluminosilicate glass, the SiO ₂ content is controlled to be 48% to 61%, specifically, including but not limited to: 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55% %, 56%, 57%, 58%, 59%, 60%.

Alumina (Al ₂ O ₃ ) is an essential component to increase the ion exchange capacity of glass, and at the same time it can improve the chemical stability and elastic modulus of glass. . When its content is too low, the voids in the network space become smaller, which is not conducive to ion migration and seriously affects the efficiency of chemical enhancement; when its content is too high, the high temperature viscosity of the glass increases significantly, the melting temperature in the production process is too high, and the energy consumption increases , it is also not conducive to the control of defects such as air bubbles and stones. Therefore, in the aluminosilicate glass, the Al ₂ O ₃ content is controlled to be 23% to 34%, preferably 26.2% to 34%, specifically, including but not limited to: 26.2%, 26.5%, 27%, 27.5% %, 28%, 28.5%, 29%, 29.5%, 30%, 29.5%, 31%, 31.5%, 32%, 32.5%, 33%, 33.5%, 34%.

Lithium oxide (Li ₂ O) is an ideal flux and an essential component for ion exchange. Due to the polarization characteristics of Li ⁺ , it can effectively reduce high temperature viscosity at high temperature. Since the present invention uses the mixed molten salt of NaNO ₃ and KNO ₃ in the strengthening process, through ion exchange between Li ⁺ in the glass and Na ⁺ in the molten salt, the depth of the compressive stress layer can be increased in a short time, so that the glass has Better mechanical shock resistance. If the content is too low, it is basically difficult for the glass to obtain higher CS _Na30 and CS _Na50 ; if the content is too high, the glass manufacturing cost will be increased, the glass expansion coefficient will increase significantly, and the glass crystallization tendency will be too high, and the probability of glass forming stone defects is obvious. Increase. Therefore, in the aluminosilicate glass, the Li ₂ O content is controlled to be 4% to 7%, preferably, the Li ₂ O content is controlled to be 4% to 5%, specifically, including but not limited to: 4%, 4.5% , 5%, 5.5%, 6%.

Sodium oxide (Na ₂ O) is another major flux, an essential component for ion exchange, which can significantly reduce the melting temperature of aluminosilicate glass, and is also an essential component for ion exchange. If the content is too low, not only the melting performance of the glass will be deteriorated, but also the stress value of the K-Na ion exchange layer will be too small, which will lead to poor microhardness, cracks easily, and drop resistance. The glass network structure is deteriorated, the stability of mechanical and thermal properties is reduced, and the chemical durability is deteriorated. Therefore, in the aluminosilicate glass, the Na ₂ O content is controlled to be 1.5% to 6%, preferably, the Na ₂ O content is controlled to be 1.5% to 5%, specifically, including but not limited to: 1.5%, 2% , 2.5%, 3%, 3.5%, 4%, 4.5%, 5%.

Potassium oxide (K ₂ O) can improve the melting properties of glass. If the content is too high, the glass network structure will be significantly deteriorated, the stability of thermal properties will be reduced, the CTE will be significantly increased, and the CS _K will be low after K-Na ion exchange. Therefore, in the aluminosilicate glass, the K ₂ O content is controlled to be 0.01% to 3%, preferably, the K ₂ O content is controlled to be 0.05% to 0.08%, specifically, including but not limited to: 0.05%, 0.06% , 0.07%, 0.08%.

Magnesium oxide (MgO) can reduce the viscosity of glass at high temperature, promote the melting and clarification of glass, and enhance the stability of glass network space at low temperature. It can reduce the thermal expansion coefficient of the glass to a certain extent, and at the same time, it can also increase the low temperature viscosity of the glass and increase the strain point of the glass, which is a necessary component. However, it has a certain hindering effect on ion exchange. When the content is too high, Mg ²⁺ seriously hinders the ion exchange capacity of the glass, resulting in a significant decrease in the depth of the compressive stress layer for K-Na exchange. Therefore, in the aluminosilicate glass, the MgO content is controlled to be 1% to 5%, specifically, including but not limited to: 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% , 5%.

Boron oxide (B ₂ O ₃ ) is a good flux, and the space end network formed by it can slide within a certain range. When the glass has stress, it can obtain a larger deformation to buffer, thereby reducing the generation of cracks and reducing the glass. elastic modulus. However, when the B ₂ O ₃ content is too high, the ion exchange capacity of the glass is significantly reduced. Therefore, in the aluminosilicate glass, the B ₂ O ₃ content is controlled to be 0.4% to 6%, preferably, the B ₂ O ₃ content is controlled to be 3.4% to 4.5%, specifically, including but not limited to: 3.4%, 4%, 4.5%.

Yttrium oxide (Y ₂ O ₃ ) is a rare earth element oxide. By adding yttrium oxide (Y ₂ O ₃ ) to increase the proportion of [BO3] triangles, the fracture state of the glass in the high ion exchange state is optimized. Therefore, in the aluminosilicate glass, the Y ₂ O ₃ content is controlled to be 0.1% to 1%, preferably, the Y ₂ O ₃ content is controlled to be 0.3% to 1%, specifically, including but not limited to: 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%. In addition, if the content of Y ₂ O ₃ is greater than 1wt% or the content of B ₂ O ₃ /Y ₂ O ₃ is less than 4, the glass cost will be seriously increased, and the content of Y ₂ O ₃ is less than 0.1wt% or the content of B ₂ O ₃ /Y ₂ O ₃ is greater than 5, the function of adjusting the ratio of [BO3] triangle and [BO4] tetrahedron will be greatly reduced.

Zirconia (ZrO ₂ ) can improve the chemical stability and ion exchange performance of the glass, increase the surface hardness of the glass, and increase the pressure required for the glass to form cracks, thereby making the glass more resistant to scratches and drops, and only a small amount of ZrO ₂ is needed. It satisfies the requirements and is therefore a required ingredient. However, too much ZrO ₂ will significantly increase the melting temperature of the glass, and at the same time will bring about defects such as stones, which will adversely affect the production. Therefore, in the aluminosilicate glass, the ZrO ₂ content is controlled to be 0.4% to 3%, preferably, the ZrO ₂ content is controlled to be 1.5% to 3%, specifically, including but not limited to: 1.5%, 2%, 2.5% , 3%.

Phosphorus pentoxide (P ₂ O ₅ ) is a non-essential component. Generally, when the content of Al ₂ O ₃ is low, a certain amount of P ₂ O ₅ is introduced, which enters the glass network and makes the network void larger than that of the aluminum oxide tetrahedron. , so it can significantly increase the ion exchange capacity. More importantly, the introduction of P ₂ O ₅ can further increase the strain point of the glass, which can alleviate the stress relaxation problem during the ion exchange process to a certain extent, so that the surface compressive stress value after strengthening can be obtained at a higher level. However, the introduction of too much P ₂ O ₅ significantly increases the thermal expansion coefficient, which in turn leads to a decrease in the surface compressive stress value. The mass percentage of P ₂ O ₅ is preferably 0% to 4%, more preferably 0% to 1.7%.

Zinc oxide (ZnO) and calcium oxide (CaO) are similar to MgO, and can enhance the stability of the glass network space at low temperature, but they also have obvious hindering effects on ion exchange, so they are not necessary components. The mass fraction of zinc oxide is preferably 0% to 2%, more preferably 0% to 1%. The mass fraction of calcium oxide (CaO) is preferably 0% to 3%, more preferably 0% to 1%.

The formulation of the above-mentioned aluminosilicate glass is further optimized to achieve better comprehensive performance.

In one specific example, the composition of the aluminosilicate glass includes: 53%-61% SiO ₂ , 23%-34% Al ₂ O ₃ , 4%-5% Li ₂ in weight percentage O, 1.7%-5.3% Na ₂ O, 0.2%-1.1% K ₂ O, 1%-5% MgO, 0.5%-5% B ₂ O ₃ , 0.15%-1% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ =4 to 5, and 0.45% to 2.8% of ZrO ₂ . Further, in terms of weight percentage, the composition of the aluminosilicate glass includes: 53%-59% SiO ₂ , 23.2%-33.5% Al ₂ O ₃ , 4%-5% Li ₂ O, 1.7%- 5.3% Na2O, 0.2%-1.1 _% K2O, ₁ %-4.1% MgO, 0.6%-5% _B2O3 , 0.15% _{-1 % Y2O3} and _{B2O 3} /Y ₂ O ₃ =4.1 to 5, and 0.49% to 2.8% of ZrO ₂ . The aluminosilicate glass of the above composition can achieve a better value of the degree of fracture γ.

In one specific example, the composition of the aluminosilicate glass includes: 55%-60.5% SiO ₂ , 23%-33.5% Al ₂ O ₃ , 4%-4.5% Li ₂ in weight percentage O, 1.7%-5.3% Na ₂ O, 0.2%-1.1% K ₂ O, 1%-4.5% MgO, 0.7%-5% B ₂ O ₃ , 0.15%-1% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ =4 to 5, and 0.45% to 2.8% of ZrO ₂ . Further, in terms of weight percentage, the composition of the aluminosilicate glass includes: 55.3%-60.2% SiO ₂ , 23.2%-33.5% Al ₂ O ₃ , 4%-4.5% Li ₂ O, 1.7%- _2.1 % Na2O, 0.2%-0.42% K2O, ₁ %-2.8% MgO, 0.7%-5% _B2O3 , 0.18% _{-1 % Y2O3} and _{B2O 3} /Y ₂ O ₃ =4.2 to 5, and 0.45% to 0.6% of ZrO ₂ . The aluminosilicate glass with the above composition has better hardness on the basis of achieving better fracture degree γ value.

In one specific example, the composition of the aluminosilicate glass includes: 53.5%-60.2% SiO ₂ , 23%-33.5% Al ₂ O ₃ , 4%-5% Li ₂ in weight percentage O, 1.7%-4.7% Na ₂ O, 0.2-0.8% K ₂ O, 1-2.8% MgO, 0.6-5% B ₂ O ₃ , 0.15-1% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ = 4.1 to 5, and 0.49% to 1.1% of ZrO ₂ . Further, in terms of weight percentage, the composition of the aluminosilicate glass includes: 58%-59% SiO ₂ , 23%-24% Al ₂ O ₃ , 4.4%-4.5% Li ₂ O, 4.4%-4.4% 4.5% Na2O, 0.7%-0.8 _% K2O, 1.5%-1.7% MgO, _2.9 % _{-3 %} B2O3, 0.6% _-0.8 % _Y2O3 and _{B2O 3} /Y ₂ O ₃ =4.1 to 4.2, 0.6% to 0.8% of ZrO ₂ , 1.6% to 1.8% of P ₂ O ₅ , 0.2% to 0.4% of ZnO, and 0.3% to 0.5% of CaO. The aluminosilicate glass with the above composition has a better DOL value on the basis of achieving a better fracture degree γ value.

In one specific example, the composition of the aluminosilicate glass includes: 53.3%-60.2% SiO ₂ , 23.2%-33.5% Al ₂ O ₃ , 4%-4.5% Li ₂ in weight percentage O, 1.7%-4.5% Na ₂ O, 0.2%-0.9% K ₂ O, 1%-3.3% MgO, 0.7%-5% B ₂ O ₃ , 0.15%-1% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ = 4.1 to 5, and 0.45% to 1.1% of ZrO ₂ . Further, in terms of weight percentage, the composition of the aluminosilicate glass includes: 55.3%-60.2% SiO ₂ , 23.2%-33.5% Al ₂ O ₃ , 4%-4.5% Li ₂ O, 1.7%- 2.2% Na2O, 0.2%-0.42 _% K2O, ₁ %-2.8% MgO, 0.75%-5% _B2O3 , 0.15% _{-1 % Y2O3} and _{B2O 3} /Y ₂ O ₃ =4.2 to 5, and 0.45% to 0.58% of ZrO ₂ . The aluminosilicate glass with the above composition has a lower thermal expansion coefficient on the basis of achieving a better fracture degree γ value.

Further, in one specific example, the composition of the aluminosilicate glass includes: 60%-60.2% SiO ₂ , 23%-23.5% Al ₂ O ₃ , 3.9%-4.1% in weight percentage % Li ₂ O, 1.7%-1.8% Na ₂ O, 0.1%-0.3% K ₂ O, 1%-1.1% MgO, 4.9%-5% B ₂ O ₃ , 0.9%-1.1% of Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ = 4.9 to 5, 0.4 to 0.5% of ZrO ₂ , 0.9 to 1.1% of P ₂ O ₅ , 0.6 to 0.7% of ZnO, 1.4 %～1.6% CaO.

In one specific example, the composition of the aluminosilicate glass includes: 55%-56% SiO ₂ , 23%-24% Al ₂ O ₃ , 4%-4.5% Li ₂ in weight percentage O, 4%-5% Na ₂ O, 1%-1.1% K ₂ O, 1%-1.5% MgO, 4%-5% B ₂ O ₃ , 0.8%-1% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ = 4.2 to 4.5, 2.6% to 2.8% of ZrO ₂ , 0.4% to 0.5% of P ₂ O ₅ , 1% to 1.5% of ZnO, 0.1% to 0.5% CaO.

In one specific example, the composition of the aluminosilicate glass includes: 53%-53.5% SiO ₂ , 28%-29% Al ₂ O ₃ , 4.2%-4.7% Li ₂ in weight percentage O, 3%-3.5% Na ₂ O, 0.5%-1% K ₂ O, 3%-4% MgO, 3%-4% B ₂ O ₃ , 0.5%-1% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ =4 to 4.2, 0.8% to 1.5% of ZrO ₂ , and 0.4% to 0.8% of CaO.

In one specific example, the composition of the aluminosilicate glass includes: 53.5%-54.5% SiO ₂ , 30%-32% Al ₂ O ₃ , 4.5%-5% Li ₂ in weight percentage O, 4.5%-5% Na ₂ O, 0.3%-0.5% K ₂ O, 2.5%-3% MgO, 0.5%-0.7% B ₂ O ₃ , 0.15%-0.3% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ =4 to 4.5, 0.8% to 1.2% of ZrO ₂ , and 0.2% to 0.4% of CaO.

In one specific example, the composition of the aluminosilicate glass includes: 55%-57% SiO ₂ , 25%-27% Al ₂ O ₃ , 4%-4.5% Li ₂ in weight percentage O, 5%-5.3% Na ₂ O, 0.7%-1% K ₂ O, 3.8%-4.5% MgO, 1%-1.6% B ₂ O ₃ , 0.2%-0.5% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ =4.8 to 5, and 1.5% to 2% of ZrO ₂ .

In one specific example, the composition of the aluminosilicate glass includes: 54.5%-56% SiO ₂ , 32%-33.5% Al ₂ O ₃ , 4%-5% Li ₂ in weight percentage O, 1.8%-2.5% Na ₂ O, 0.2%-0.6% K ₂ O, 2%-3.5% MgO, 0.5%-1.2% B ₂ O ₃ , 0.15%-0.3% Y ₂ O ₃ and B ₂ O ₃ /Y ₂ O ₃ =4.2 to 4.5, and 0.5% to 0.7% of ZrO ₂ .

The present invention also provides the preparation method of the aluminosilicate reinforced glass, comprising the following steps:

The raw materials are mixed according to the composition of the aluminosilicate glass, and subjected to melting treatment, followed by annealing and molding to prepare the aluminosilicate glass;

The aluminosilicate glass was immersed in a mixed molten salt of NaNO ₃ and KNO ₃ for ion exchange to prepare the aluminosilicate reinforced glass.

The specific preparation process of the aluminosilicate glass involved in the present invention can be obtained in the traditional flat glass manufacturing process, and the manufacturing process is not limited to the float forming process, the overflow down-drawing method, the drawing-up method, the flat-drawing method and the calendering method. Wait.

In one example, the temperature of the melting process is 1500°C to 1700°C.

In one example, the annealing temperature is 550°C to 750°C.

In one example, the molten salt includes 3%-15% NaNO ₃ and 85%-97% KNO ₃ in terms of mass percentage. If the mass percentage of NaNO ₃ is too low, the ion exchange rate of Li-Na is too slow, and the surface enrichment of K+ is likely to occur, blocking the ion exchange of Li-Na; if it is too high, the Na-K ion exchange efficiency will be significantly decreased, resulting in the inability to form a higher compressive stress on the glass surface.

In one example, the temperature of the ion exchange is 390°C to 460°C. If the temperature is too low, the ion exchange rate is too slow, and the strengthening time needs to be increased to obtain acceptable mechanical properties; if the temperature is too high, stress relaxation is likely to occur, resulting in a decrease in CS. It is difficult to obtain a larger CS value, and the high strengthening temperature is likely to cause problems such as glass warpage and self-explosion, and other yield reduction problems. Specifically, the temperature of ion exchange includes but is not limited to: 390°C, 400°C, 410°C, 420°C, 430°C, and 440°C.

In one example, the time for ion exchange is 120 min to 180 min. If the ion exchange time is too short, the degree of ion exchange will be insufficient, and the CS and DOL values will not meet expectations; if the ion exchange time is too long, the DOL will not be significantly improved, but the stress value will be significantly reduced. , it is easy to produce irreversible structural defects inside the glass. Specifically, the time of ion exchange includes but is not limited to: 120min, 125min, 130min, 135min, 140min, 145min, 150min, 155min, 160min, 165min, 170min, 175min, 180min.

The present invention also provides a glass protective layer comprising the above-mentioned aluminosilicate reinforced glass. Specifically, the glass protective layer can be a glass cover plate, especially an electronic touch screen cover plate, or a glass cover plate of electronic products such as high-speed railway, aerospace, deep-sea detection equipment and other special equipment.

The following are specific examples.

In Table 1, commonly used glass raw materials such as oxides and carbonates are appropriately selected to have the compositions shown in the table, weighed to obtain batches of more than 1000 g, and thoroughly mixed with stirring. Put the batch mixture into a platinum crucible larger than 400ml, put the platinum crucible into a silicon molybdenum furnace, heat it up to 1670 ° C, and melt and clarify it for more than 8 hours, homogenize it and cast it into a mold, and anneal it below 750 ° C Precision annealing is carried out at the temperature, and then a bulk glass is obtained. The block glass is precision wire cut, and both surfaces are ground and polished to obtain 50*50mm glass with a thickness of 0.7.

Before chemical strengthening, 2.5D polishing, 3D hot bending and other processing processes can be performed on the glass backplane to meet the needs of the appearance design of electronic products. The above glass is then subjected to a special one-step ion exchange. After cooling, it is cleaned with an ultrasonic cleaner for 1 hour to wash off the residual molten salt on the glass surface, and it is tested after drying.

The high temperature viscosity test was carried out on the original glass sheet without ion exchange, and the high temperature viscometer of ORTON in the United States was used to test to determine the melting and clarification temperature Tm (10 ² dPa.s) of the glass; the thermal expansion performance test was carried out on the tightly cut glass samples, The PC402L horizontal dilatometer from NETZSCH was used to test to determine the glass transition temperature Tg (10 ^13.4 dPa.s) and thermal expansion performance (35℃～350℃). Glass samples were subjected to Vickers microhardness testing.

The tempering stress test was performed on the tempered glass of each example and the comparative example, and the data were recorded in the table. The instruments used are FSM-6000LE birefringence stress meter and scattered photoelastic stress meter SLP-1000 to conduct CS and DOL tests on the ion-exchanged tempered glass of each embodiment respectively. Using the birefringence imaging system, the polarized light of a specific wavelength passes through the glass with a stress gradient to generate a refractive optical path difference, and calculate the relevant stress distribution indicators: CS _Na30 , CS _Na50 , CS _K , DOL, CT, DOL _K . Taking Example 1 as an example, its test curve is shown in Figures 1 and 2.

Note: CS _Na30 refers to the compressive stress value of the tempered glass sample at a depth of 30 microns after being strengthened by mixed salts. Since its compressive stress value is mainly due to the Na ion in the tempered salt exchanging Li ions in the glass, it is called CS _Na30 ;

CS _Na50 , the same as CS _Na30 , refers to the compressive stress value of the strengthened glass at a depth of 50 microns;

CS _K refers to the compressive stress value on the surface of the strengthened glass, because it mainly replaces the Na ions in the glass by the K ions in the strengthened salt, so it is called CS _k ;

DOL refers to the compressive stress depth of strengthened glass;

CT refers to the tensile stress value in the center of the strengthened glass;

DOL _K refers to the depth of the high compressive stress layer on the surface of the strengthened glass, which mainly replaces the Na ions in the glass by the K ions in the strengthened salt, so it is called DOL _K , also called the K stress depth.

Taking Example 5 as an example, as shown in Figure 3, the breaking degree factor γ is introduced to represent the breaking of the tempered glass when the glass is squeezed by a sharp foreign object. Small, we pass the coated 50*50*0.7mm tempered glass through Dongguan Lichen's Compress System 310 edge blanking machine, and slowly pressurize it under the pressure head with a tip diameter of 0.5mm until it breaks, and remove the breaking point. The average diameter of the 5 largest fragments is the value of the fragmentation factor γ.

Remarks: In the actual application process of cover glass, try to avoid a large number of fine glass particles after breaking, that is, the breaking degree factor γ needs to be as large as possible. The main reasons are: 1. After breaking into small particles, dense cracks are generated, although Because the OCA glue still maintains the corresponding shape, but a large number of broken cracks have blocked the screen display, the mobile phone or other smart devices will completely lose the display function and cannot be used; Second, fine glass particles may enter the user's Eyes, mouths, etc., especially children, will also stab exposed body parts such as hands because the particles are too fine.

Table 1

Table 2

table 3

Table 4

table 5

In Comparative Example 1, 7.8wt% Na ₂ O glass component was selected, and the remaining components were within the scope of the present invention. The thermal expansion coefficient was significantly increased to 88.2*10 ^-7 , and the microhardness was reduced to 572Hv. % sodium nitrate and 90 wt% potassium nitrate mixed melt, at 400 ℃, after 2.5 hours, the stress tester detects that the CS _Na30 is 142MPa, the CS _Na50 is 80MPa, the CS _K is 894MPa, and the DOL is 138μm, CT is 70.6MPa, DOL _K is 9.8μm, and its fragmentation γ value is 6mm.

In Comparative Example 2, 5.9wt% of MgO glass components were selected, and the remaining components were within the scope of the present invention. The thermal expansion coefficient was significantly increased to 79.5* ^10-7 , and the microhardness was reduced to 588Hv. In the mixed melt of sodium nitrate and 90wt% potassium nitrate, at a temperature of 420 ℃, after 2 hours, the stress tester detects that the CS _Na30 is 169MPa, the CS _Na50 is 98MPa, the CS _K is 806MPa, and the DOL is 114μm. CT was 57.1MPa, DOL _K was 4.9μm, and its fragmentation γ value was 3mm.

In Comparative Example 3, 7.8wt% Na ₂ O and ^5.9wt % MgO glass components were selected, and the remaining components were within the scope of the present invention. The glass sample was immersed in a mixed melt of 50wt% sodium nitrate and 50wt% potassium nitrate. After 3 hours at a temperature of 430°C, it was tested by a stress tester. The CS _Na30 was 229MPa, the CS _Na50 was 139MPa, and the CS Na50 was 139MPa. _K is 486MPa, DOL is 135μm, CT is 90.4MPa, DOL _K is 4.5μm, and its fragmentation γ value is 2.5mm.

The glass components of Comparative Example 4 are all within the scope of the present invention, the thermal expansion coefficient is 78.2*10 ^-7 , and the microhardness is 619Hv. The glass sample is tempered by a two-step method, first immersed in 50wt% sodium nitrate and 50wt% In the mixed melt of potassium nitrate, after 3.5 hours at a temperature of 395 °C; Tested by the stress tester, its CS _Na30 is 288MPa, CS _Na50 is 189MPa, CS _K is 992MPa, DOL is 132μm, CT is 129.8MPa, DOL _K is 3.2μm, and its fragmentation γ value is 0.8mm.

The glass components of Comparative Example 5 are all within the scope of the present invention, the thermal expansion coefficient is 63.4*10 ^-7 , the microhardness is 609Hv, and the glass sample is immersed in a mixed melt of 90wt% sodium nitrate and 10wt% potassium nitrate. , at 445℃, after 2.5 hours, the stress tester detects that its CS _Na30 is 231MPa, CS _Na50 is 163MPa, CS _K is 958MPa, DOL is 131μm, CT is 109.6MPa, DOL _K is 11.6μm, its The fragmentation degree γ value was 1.6 mm.

In Comparative Example 6, on the basis of Example 18, Y ₂ O ₃ was adjusted from 0.25 wt % to 0.15 wt %, and its B ₂ O ₃ /Y ₂ O ₃ = 7. It can be found that the basic properties did not change significantly, but Its breaking factor is reduced from 18 to 7.9, and the breaking degree of its tempered glass is greatly increased. This is because the amount of Y ₂ O ₃ is too small to adjust the ratio of [BO ₃ ] triangle and [BO ₄ ] tetrahedron. Ability.

In Comparative Example 7, on the basis of Example 18, Y ₂ O ₃ was adjusted from 0.25 wt % to 0.5 wt %, and its B ₂ O ₃ /Y ₂ O ₃ = 2.1, it could be found that the basic properties did not change significantly, and Its breaking factor is increased from 18 to 18.2, and the breaking degree of its tempered glass is not improved because of the increase of Y ₂ O ₃ , because the amount of Y ₂ O ₃ has basically reached the adjustment of [BO ₃ ] triangle and [BO 3 ] ₄ ] The limit of the tetrahedral ratio, continue to increase Y ₂ O ₃ , can only greatly increase the cost of glass production.

Example 19 On the base component of Example 5, Y ₂ O ₃ was reduced to 0.1%, the reduced part was added to SiO ₂ , and its glass sample was immersed in a mixed melt of 10 wt % sodium nitrate and 90 wt % potassium nitrate At 420 °C, after 2 hours, the stress tester detects that its CS _Na30 is 208MPa, CS _Na50 is 133MPa, CS _K is 906MPa, DOL is 124μm, CT is 79.84MPa, DOL _K is 5.3μm, The exchange of potassium and sodium ions in the surface layer was inhibited, CS _K and DOL _K decreased slightly, but the fragmentation γ value decreased to 16.9mm.

Example 20 On the base component of Example 5, K ₂ O was increased to 2%, and the SiO ₂ component was reduced, and the glass sample was immersed in a mixed melt of 10 wt % sodium nitrate and 90 wt % potassium At 420℃, after 2 hours, the stress tester detects that the CS _Na30 is 176MPa, the CS _Na50 is 132MPa, the CS _K is 933MPa, the DOL is 122μm, the CT is 88.46MPa, and the DOL _K is 6.8μm. The gamma value has dropped to 19.8mm.

Example 21 On the base component of Example 5, the B ₂ O ₃ was increased to 6% and the SiO ₂ component was reduced, and the glass sample was immersed in a mixed melt of 10 wt % sodium nitrate and 90 wt % potassium nitrate, At 420℃, after 2 hours, the stress tester detects that the CS _Na30 is 182MPa, the CS _Na50 is 98MPa, the CS _K is 825MPa, the DOL is 113μm, the CT is 76.5MPa, and the DOL _K is 5.1μm. The potassium-sodium ion exchange was inhibited, but its fragmentation γ value decreased to 22.4 mm.

Example 22 On the base component of Example 5, the Al ₂ O ₃ was reduced to 23%, the SiO ₂ component was added, and the glass sample was immersed in a mixed melt of 10 wt % sodium nitrate and 90 wt % potassium nitrate, At 420℃, after 2 hours, the stress tester detects that its CS _Na30 is 192MPa, CS _Na50 is 134MPa, CS _K is 923MPa, DOL is 115μm, CT is 82.6MPa, DOL _K is 6μm, and its surface potassium The sodium ion exchange was inhibited, but its fragmentation γ value decreased to 23.1 mm.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (12)

1. An aluminosilicate reinforced glass, characterized in that the aluminosilicate glass is strengthened in one step by using a mixed molten salt of NaNO ₃ and KNO ₃ ; in weight percentage, the composition of the aluminosilicate glass includes:

   48%-61% SiO ₂ , 23%-34% Al ₂ O ₃ , 4%-7% Li ₂ O, 1.5%-6% Na ₂ O, 0.01%-3% K ₂ O, ₁ %-5% MgO, 0.4%-6% B2O3, 0.1% _{-1 % Y2O3} and the mass ratio _{of B2O3} and _Y2O3 is 4-5, and 0.4 _% ~ ₃ % ZrO2.
2. The aluminosilicate strengthened glass according to claim 1, characterized in that, by weight percentage, the composition of the aluminosilicate glass comprises:

   53%-61% SiO ₂ , 23%-34% Al ₂ O ₃ , 4%-5% Li ₂ O, 1.7%-5.3% Na ₂ O, 0.2%-1.1% K ₂ O, ₁ %-5% MgO, _0.5 %-5% B2O3, 0.15% _{-1 % Y2O3} and the mass ratio _{of B2O3} and _Y2O3 is 4-5, and 0.45% ~2.8 _% ZrO2.
3. The aluminosilicate tempered glass according to claim 1 or 2, wherein, in the composition of the aluminosilicate glass, the mass ratio of B ₂ O ₃ and Y ₂ O ₃ is 4.4 to 4.97.
4. The aluminosilicate tempered glass according to claim 1 or 2, characterized in that, the composition of the aluminosilicate glass further comprises P ₂ O ₅ with a weight percentage of ≤4% in weight percentage.
5. The aluminosilicate tempered glass according to claim 1 or 2, characterized in that, the composition of the aluminosilicate glass further comprises CaO with a weight percentage of ≤3% in weight percentage.
6. The aluminosilicate reinforced glass according to claim 1 or 2, characterized in that, the composition of the aluminosilicate glass further comprises ZnO with a weight percentage of ≤2% by weight.
7. The method for preparing aluminosilicate reinforced glass according to any one of claims 1 to 6, characterized in that it comprises the following steps:

   The raw materials are mixed according to the composition of the aluminosilicate glass, and subjected to melting treatment, followed by annealing and molding to prepare the aluminosilicate glass;

   The aluminosilicate glass is immersed in a mixed molten salt of NaNO ₃ and KNO ₃ for ion exchange to prepare the aluminosilicate reinforced glass.
8. The method for preparing aluminosilicate tempered glass according to claim 7, wherein the temperature of the melting treatment is 1500°C to 1700°C; and/or

   The temperature of the annealing is 550°C to 750°C.
9. The method for preparing aluminosilicate reinforced glass according to claim 7 or 8, characterized in that, in terms of mass percentage, the molten salt comprises ₃ %-15% NaNO3 and 85%-97% NaNO3 KNO ₃ ; and/or

   The temperature of the ion exchange is 400°C to 440°C; and/or

   The time of the ion exchange is 120min-180min.
10. A glass protective layer, characterized by comprising the aluminosilicate tempered glass according to any one of claims 1 to 6.
11. A glass cover plate, characterized by comprising the aluminosilicate tempered glass according to any one of claims 1 to 6.
12. An electronic product, characterized in that the aluminosilicate tempered glass according to any one of claims 1 to 6 is used as a glass cover plate.

Images