A composition for anti-crack glass, anti-crack glass and a preparation method and application thereof

Abstract

The present application relates to a kind of anti-crack glass composition, anti-crack glass and its preparation method and application.The anti-crack glass composition includes SiO2, Al2O3, Li2O, Na2O, K2O, MgO, Y2O3 and ZrO2 in oxide form;With the total mass of anti-crack glass composition as 100wt%, the mass fraction of Al2O3 is 16wt%-21wt%, the mass fraction of Li2O is 2wt%-6.5wt%, the mass fraction of Na2O is 0.5wt%-4wt%, the mass fraction of K2O is 1wt%-4wt%, the mass fraction of MgO is 1wt%-5wt%, the mass fraction of Y2O3 is 2wt%-7wt%, the mass fraction of ZrO2 is 0.5wt%-3.5wt%, and the balance is SiO2.The anti-crack glass prepared by the anti-crack glass composition of the present application has high drop height resistance and excellent drop resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of glass, in particular to a composition for crack-resistant glass, crack-resistant glass and a preparation method and application thereof. BACKGROUND

[0002] Glass has always been an indispensable material in the development of display technology. By changing the composition of the glass surface through chemical strengthening, the strength of the glass can be improved, allowing the glass to be more widely used in the protection of display devices.

[0003] At present, cover glasses are applied to mobile devices such as mobile phones, computers, smart watches and other various mobile devices with touch screen panels, etc. for screen protection. It is generally required to have relatively optimal physical properties and high mechanical properties, such as high mechanical strength, high Young's modulus, high chemical temperature resistance and light and thin, etc., so as to avoid screen damage of the mobile device caused by external factors such as impact, falling, scratching, extrusion, etc. during use.

[0004] Studies have shown that 80% of mobile phone screen breakage is caused by accidental falling. Conventional chemically strengthened glass has reached a high level in terms of resistance to impact by flat objects, but is generally weak in terms of resistance to impact by sharp objects (falling resistance). For example, glass products are prone to cracking and breaking when falling from a high place to a rough surface (such as a cement floor, sand, sandpaper, etc.).

[0005] The glass products have very limited anti-falling and anti-impact ability in the prior art. Therefore, how to provide a glass composition to improve the anti-falling and anti-cracking ability of the glass product is still a problem to be solved at present. SUMMARY

[0006] To solve the above technical problems, the present application aims to provide a composition for crack-resistant glass, crack-resistant glass and a preparation method and application thereof. The crack-resistant glass prepared from the composition for crack-resistant glass has high anti-falling height and excellent anti-falling performance.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a composition for crack-resistant glass, which comprises SiO2, Al2O3, Li2O, Na2O, K2O, MgO, Y2O3 and ZrO2 in the form of oxides.

[0009] The mass fraction of Al2O3 is 16wt%-21wt% based on 100wt% of the total mass of the composition for crack-resistant glass, for example, it can be 16wt%, 17wt%, 18wt%, 19wt%, 20wt% or 21wt%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0010] In the present application, Al2O3 is introduced to improve the strength of the glass structure. Non-bridging oxygen forms aluminum-oxygen tetrahedron with Al, which is larger than silicon-oxygen tetrahedron, resulting in larger gaps in the glass structure, which is beneficial to ion exchange, and ultimately makes the chemical strengthening effect better, improving the scratch resistance and drop resistance of the glass. However, if the content of Al2O3 is too high, it is difficult to melt; if the content of Al2O3 is too low, the glass is prone to crystallization, and the mechanical strength is low, which is not conducive to forming. The content of Al2O3 in the present application is 16wt%-21wt%.

[0011] The mass fraction of Li2O is 2wt%-6.5wt% based on the total mass of the anti-crack glass composition, for example, it can be 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt% or 6.5wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0012] The mass fraction of Na2O is 0.5wt%-4wt% based on the total mass of the anti-crack glass composition, for example, it can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt% or 4wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0013] The mass fraction of K2O is 1wt%-4wt% based on the total mass of the anti-crack glass composition, for example, it can be 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt% or 4wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0014] Li2O, Na2O and K2O introduced in the present application are the main exchange ions in the chemical strengthening process. Li + has a smaller ionic radius than Na + , and the glass containing Li + has a faster ion exchange speed, so that the glass obtains a thicker strengthened layer in a short time. Li + ions exchange with Na + ions in the molten liquid, and the speed is faster than Na + and K +The exchange speed is fast. However, when the content of Li2O is high, the refractory material is eroded seriously. When the contents of Na2O and K2O are high, the expansion coefficient of the glass is increased, the mechanical properties of the glass are reduced, and the chemical strengthening speed is affected. The content of Li2O in the application is 2wt%-6.5wt%, the content of Na2O is 0.5wt%-4wt%, and the content of K2O is 1wt%-4wt%.

[0015] The mass fraction of MgO is 1wt%-5wt% based on the total mass of the composition for the crack-resistant glass, for example, can be 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt% or 5wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0016] In the application, MgO is introduced to improve the glass Na + and Li + ion exchange performance, improve the thermal performance, chemical stability and mechanical strength of the glass. The content of MgO in the application is 1wt%-5wt%.

[0017] The mass fraction of Y2O3 is 2wt%-7wt% based on the total mass of the composition for the crack-resistant glass, for example, can be 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt% or 7wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0018] In the application, Y2O3 is introduced, and because the ionic radius of Y is close to that of Na, the internal Na + and Li + ion exchange rate can be adjusted, which is beneficial to improve the CS-Na 30 and CS-Na 50 ; at the same time, Y2O3 improves the strain point of the glass, thereby improving the stress relaxation caused by the chemical strengthening process of the glass for a long time or at high temperature. The content of Y2O3 in the application is 2wt%-7wt%.

[0019] The mass fraction of ZrO2 is 0.5wt%-3.5wt% based on the total mass of the composition for the crack-resistant glass, for example, can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt% or 3.5wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable. The balance is SiO2.

[0020] The present application introduces ZrO2, which is in the network space, has an accumulation effect on the surrounding silicon oxygen tetrahedron, and can enhance the network structure; at the same time, the internal chemical strengthening stress intensity, ion exchange speed and depth of the glass are enhanced. The content of ZrO2 in the present application is 0.1wt%-0.5wt%.

[0021] In the present application, SiO2 is introduced, which is a component constituting the glass framework. SiO2 can serve as the main body of the glass network structure. If the content is low, it is not easy to form glass, the strain point decreases, the expansion coefficient increases, the acid resistance and alkali resistance decrease, and the glass stability is poor. Increasing the content of SiO2 can improve the mechanical strength of the glass, reduce the expansion coefficient, and improve the stability of the glass. However, if the content is too high, the high-temperature viscosity of the glass increases, which is not conducive to the melting of the glass. In the present application, the mass fraction of SiO2 in the composition for anti-crack glass is 61wt%-65wt%.

[0022] The following is a preferred technical solution of the present application, but not as a limitation on the technical solutions provided by the present application. Through the following preferred technical solution, the technical purpose and beneficial effects of the present application can be better achieved and realized.

[0023] Preferably, the mass fraction of each component in the anti-crack glass composition satisfies at least one of the following conditions: (i) 3.91≤A=(SiO2-Al2O3) / (MgO+Y2O3+ZrO2)≤5.87; (ii) 0.38≤B=(Li2O-Na2O) / K2O≤2.5; (iii) 0.27≤C=(Y2O3-Na2O) / (ZrO2+MgO)≤0.76.

[0024] (i) 3.91≤A=(SiO2-Al2O3) / (MgO+Y2O3+ZrO2)≤5.87, for example, can be 3.91, 4.0, 4.1, 4.2, 4.3, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8 or 5.87, but is not limited to the listed values, other values not listed within the value range are also applicable.

[0025] The present application controls 3.91≤A=(SiO2-Al2O3) / (MgO+Y2O3+ZrO2)≤5.87. Within this range, SiO2 is the glass network structure, on the one hand, SiO2 is replaced by [AlO4], which has a larger volume compared to the glass network structure silicon oxygen tetrahedron, can improve the ion exchange speed during subsequent glass strengthening, and improve the damage resistance of the glass, without damaging the overall network structure of the glass. On the other hand, MgO+Y2O3+ZrO2 as the network outside body, has a significant accumulation effect in the glass network gap, and can enhance the glass network structure.

[0026] Preferably, the anti-cracking glass composition mass fraction satisfies: (ii) 0.38≤B=(Li2O-Na2O) / K2O≤2.5, for example, it can be 0.38, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5, but not limited to the listed values, other values not listed in the value range are also applicable.

[0027] The present application controls 0.38≤B=(Li2O-Na2O) / K2O≤2.5, in this range, it is beneficial for Li + , Na + , K + exchange between each other, to produce sufficient ion exchange depth, and improve the chemical strengthening performance of the glass.

[0028] Preferably, the anti-cracking glass composition mass fraction satisfies: (iii) 0.27≤C=(Y2O3-Na2O) / (ZrO2+MgO)≤0.76, for example, it can be 0.27, 0.28, 0.29, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 or 0.76, but not limited to the listed values, other values not listed in the value range are also applicable.

[0029] The present application controls 0.27≤C=(Y2O3-Na2O) / (ZrO2+MgO)≤0.76, in this range, it can improve the thermal performance of the glass, and improve the strain point of the glass. It can improve the stress relaxation of the glass caused by the long time or high temperature chemical strengthening in the first step of chemical strengthening; at the same time, it can improve the second step of chemical strengthening performance, and further improve CS-Na 30 , CS-Na 50 .

[0030] The present application can improve the drop height resistance of the anti-cracking glass, and improve the drop resistance of the anti-cracking glass by optimizing and controlling the mass fraction of SiO2, Al2O3, Li2O, Na2O, K2O, MgO, Y2O3 and ZrO2 in the anti-cracking glass composition.

[0031] In the second aspect, the present application provides an anti-cracking glass, which comprises the anti-cracking glass composition of the first aspect.

[0032] The anti-crack glass provided by the application has simple composition, high anti-falling height and excellent anti-falling performance. The thickness of the anti-crack glass is 0.08mm-1.5mm, and the thinner the anti-crack glass is, the lighter the glass can be.

[0033] Preferably, the CS-K of the anti-crack glass is greater than or equal to 950MPa, for example, can be 950MPa, 955MPa, 1000MPa, 1005MPa, 1010MPa, 1015MPa, 1020MPa, 1025MPa or 1030MPa, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0034] In the application, CS-K refers to the compressive stress value of the surface of the strengthened glass, which is mainly achieved by replacing K ions in the strengthening salt with Na ions in the glass.

[0035] Preferably, the CS-Na 30 of the anti-crack glass is greater than or equal to 160MPa, for example, can be 160MPa, 165MPa, 170MPa, 175MPa, 180MPa, 185MPa, 190MPa, 195MPa or 200MPa, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0036] Preferably, the CS-Na 50 of the anti-crack glass is greater than or equal to 130MPa, for example, can be 130MPa, 132MPa, 134MPa, 136MPa, 138MPa, 140MPa, 142MPa, 144MPa, 146MPa, 148MPa, 150MPa, 152MPa, 154MPa, 156MPa, 158MPa or 160MPa, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0037] In the application, CS-Na 30 refers to the compressive stress value of the 30μm deep position of the strengthened glass sample after mixed salt strengthening, and the compressive stress value is mainly achieved by exchanging Li ions in the glass with Na ions in the strengthening salt.

[0038] In the application, CS-Na 50 refers to the compressive stress value of the 50μm deep position of the strengthened glass sample after mixed salt strengthening, and the compressive stress value is mainly achieved by exchanging Li ions in the glass with Na ions in the strengthening salt.

[0039] Preferably, the anti-cracking glass has a DOL-Na≥ 120 μm, for example, it can be 120 μm, 122 μm, 124 μm, 126 μm, 128 μm, 130 μm, 132 μm, 134 μm, 136 μm, 138 μm, 140 μm, 142 μm, 144 μm, 146 μm, 148 μm, or 150 μm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0040] Preferably, the anti-cracking glass has a DOL-K≥ 7 μm, for example, it can be 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, or 15 μm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0041] DOL-Na refers to the depth of Na ion exchange in the compressive stress layer of the strengthened glass. DOL-K refers to the depth of K ion exchange in the compressive stress layer of the strengthened glass.

[0042] Preferably, the anti-cracking glass has a drop height resistance≥ 120 cm, for example, it can be 120 cm, 122 cm, 124 cm, 126 cm, 128 cm, 130 cm, 132 cm, 134 cm, 136 cm, 138 cm, 140 cm, 142 cm, 144 cm, 146 cm, 148 cm, 150 cm, 152 cm, 154 cm, 156 cm, 158 cm, or 160 cm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0043] Preferably, the anti-cracking glass has a crack resistance factor D = [(CS-Na 30 )-(CS-Na 50 )] / 20 μm, D≥ 1.6 MPa·μm -1 , preferably in the range of 1.6 MPa·μm -1 ≤ D≤ 2 MPa·μm -1 , for example, it can be 1.6 MPa·μm -1 , 1.7 MPa·μm -1 , 1.8 MPa·μm -1 , 1.9 MPa·μm -1 , or 2 MPa·μm -1 , but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0044] The inventors have found that when the glass falls from a height to 180 mesh sandpaper, the surface of the glass directly contacts the protruding part (30-50 microns) of the 180 mesh sandpaper, and the stress value at this position is mainly generated by the exchange of Li ions in the glass with Na ions in the strengthening salt. Therefore, if the surface compressive stress layer of the glass is too low in strength or too thin in depth, the stress layer of the glass is easily pierced by the protruding sharp part, cracks are generated, and the glass breaks, and the drop height resistance of the glass is low.

[0045] The present application proposes a crack resistance factor D, which is obtained by the ratio of the stress difference of CS-Na 30 , CS-Na 50 at 20 microns, and CS-Na 30 , CS-Na 50 respectively correspond to the compressive stress values at the 30 micron depth position and the 50 micron depth position of the strengthened glass sample after mixed salt strengthening. The range of D is 1.6 MPa·μm -1 Above, the crack resistance of the glass in this range is excellent, and the preferred range is 1.6 MPa·μm -1 ≤D≤2 MPa·μm -1 .

[0046] In a third aspect, the present application provides a method for preparing the crack resistance glass according to the second aspect, which comprises the following steps:

[0047] Melting the composition of the crack resistance glass, and then clarifying, homogenizing, forming, annealing and chemically strengthening to obtain the crack resistance glass.

[0048] The present application adopts a conventional method for preparing the crack resistance glass, wherein the clarifying agent added in the clarifying process comprises one or a combination of at least two of sodium chloride, mirabilite or cerium oxide, and the mass of the composite clarifying agent is 0.1wt%-0.5wt% of the total mass of the raw materials for the crack resistance glass.

[0049] Preferably, the forming method comprises any one of float method, slot down-draw method, casting method or overflow method.

[0050] Preferably, the chemical strengthening step comprises:

[0051] S1: using sodium ion molten salt to strengthen at 430-480℃ for 1-2h; for example, the temperature can be 430℃, 440℃, 450℃, 460℃, 470℃ or 480℃, and the time can be 1h, 1.5h or 2h, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0052] S2: strengthening at 400℃-430℃ for 1h-2h using potassium ion molten salt; for example, the temperature can be 400℃, 405℃, 410℃, 415℃, 420℃, 425℃ or 430℃, and the time can be 1h, 1.5h or 2h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0053] The sodium ion molten salt used in S1 can be a NaNO3 molten salt with a mass fraction of 100wt%.

[0054] The potassium ion molten salt used in S2 can be a KNO3 molten salt with a mass fraction of 100wt%.

[0055] Preferably, the chemical strengthening is followed by cleaning and drying the crack-resistant glass.

[0056] In a fourth aspect, the present application provides the use of the crack-resistant glass according to the third aspect in front or back covers for touch display screens, electronic smart terminals, photovoltaic power generation devices, automobile windows, automobile protective glass, pharmaceutical glass containers or primary packaging.

[0057] The crack-resistant glass obtained by the present application has excellent physical and chemical properties and mechanical properties, and can be applied in front or back covers for touch display screens, electronic smart terminals, photovoltaic power generation devices, automobile windows, automobile protective glass, pharmaceutical glass containers or primary packaging, etc.

[0058] The numerical ranges described in the present application include not only the listed point values, but also any point values between the listed values, and the present application does not exhaustively list the specific point values included in the range for the sake of brevity and simplicity.

[0059] Compared with the prior art, the present application has at least the following beneficial effects:

[0060] The crack-resistant glass prepared from the crack-resistant glass composition provided by the present application has high drop height resistance and excellent drop resistance. The crack-resistant glass prepared has a crack resistance factor D = [(CS-Na 30 )-(CS-Na 50 )] / 20μm, and D is in the range of 1.6MPa·μm -1 The drop height resistance of the crack-resistant glass is ≥120cm. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 FIG. 1 is a graph showing the relationship between the D value of the crack-resistant glass prepared in Examples 1-10 of the present application and the drop height resistance of 180-mesh sandpaper. DETAILED DESCRIPTION

[0062] The technical solutions of the present application are further illustrated below in conjunction with the accompanying drawings and through specific embodiments. However, the following examples are merely simple examples of the present application and do not represent or limit the protection scope of the present application, and the protection scope of the present application is subject to the claims.

[0063] In the following examples and comparative examples, all reagents and consumables are purchased from conventional reagent manufacturers in the art unless otherwise specified; and the experimental methods and technical means used are conventional methods and means in the art unless otherwise specified.

[0064] Example 1

[0065] The present embodiment provides a composition for anti-crack glass: the mass fraction of Al2O3 is 16wt%, the mass fraction of Li2O is 6.5wt%, the mass fraction of Na2O is 4wt%, the mass fraction of K2O is 1wt%, the mass fraction of MgO is 1wt%, the mass fraction of Y2O3 is 7wt%, the mass fraction of ZrO2 is 3.5wt%, and the balance is SiO2, based on the total mass of the composition for anti-crack glass being 100wt%; and A=(SiO2-Al2O3) / (MgO+Y2O3+ZrO2)=3.91, B=(Li2O-Na2O) / K2O=2.5, C=(Y2O3-Na2O) / (ZrO2+MgO)=0.67, and the content of each component is shown in Table 1.

[0066] The preparation method of the anti-crack glass provided by the present embodiment includes the following steps:

[0067] The glass composition is mixed in a mass ratio and poured into a platinum-rhodium crucible, and a clarifier of NaNO3 and CeO2 in a mass ratio of 1:1 is added, the clarifier is added in an amount of 0.3wt% of the total amount of raw materials for the anti-crack glass, and is heated at 1600℃ for 5h and mixed uniformly. Subsequently, the crucible is taken out, the melted glass liquid is poured into a preheated mold to form by casting, after forming, it is placed in a 600℃ muffle furnace for 2h for annealing treatment, and after the muffle furnace is cooled to room temperature, the formed anti-crack glass is taken out, and the formed anti-crack glass is preheated at a preheating temperature of 380℃ for 30min to obtain the anti-crack glass after pretreatment.

[0068] The anti-crack glass after pretreatment is chemically strengthened, and the chemical strengthening includes the following steps:

[0069] S1: using a molten salt of NaNO3 with a mass fraction of 100wt% to strengthen at 430℃ for 2h;

[0070] S2: using a molten salt of KNO3 with a mass fraction of 100wt% to strengthen at 400℃ for 1h to obtain the anti-crack glass.

[0071] Example 2

[0072] The present example provides a composition for crack-resistant glass, the content of which is shown in Table 1; the preparation method of the crack-resistant glass provided by the present example comprises the following steps:

[0073] The glass composition is mixed according to the mass ratio, poured into a platinum-rhodium crucible, and 1:1 NaCl and CeO2clarifying agents are added, the amount of clarifying agent is 0.1wt% of the total amount of crack-resistant glass raw materials, heated at 1560℃ for 5h and mixed uniformly. Then the crucible is taken out, the melted glass liquid is poured into a preheated mold to form by casting method, after forming, it is placed in a 550℃ muffle furnace for annealing treatment for 3h, and then taken out when the muffle furnace cools to room temperature to obtain the shaped crack-resistant glass, and the shaped crack-resistant glass is preheated at a temperature of 400℃ for 30 minutes to obtain the pre-processed crack-resistant glass.

[0074] The pre-processed crack-resistant glass is chemically strengthened, and the chemical strengthening comprises the following steps:

[0075] S1: using 100wt% NaNO3molten salt, strengthening at 430℃ for 2h;

[0076] S2: using 100wt% KNO3molten salt, strengthening at 400℃ for 1.5h to obtain the crack-resistant glass.

[0077] Examples 3-10

[0078] The content of the crack-resistant glass composition in each example is shown in Table 1;

[0079] The preparation method of the crack-resistant glass provided by the present example is the same as that of Example 1 except for the chemical strengthening step, and the chemical strengthening conditions are shown in Table 2.

[0080] Comparative Example 1

[0081] The content of the glass composition of Comparative Example 1 is shown in Table 1;

[0082] The preparation method of Comparative Example 1 comprises the same chemical strengthening steps as Example 1.

[0083] Test method

[0084] The glass prepared in Examples 1-10 and Comparative Example 1 is tested, and the test results are shown in Table 3.

[0085] According to the above glass performance test requirements, the performance of the glass is tested. The CS and DOL of the strengthened glass of each embodiment after ion exchange are tested by using Japan OZAWA FSM-6000LE+SLP1000 surface stress meter. By using a birefringence imaging system, a specific wavelength of polarized light passes through the glass with a stress gradient, generating a refractive path difference, and calculating the relevant stress distribution indicators: CS-K, CS-Na 30 , CS-Na 50 , DOL-Na, DOL-K.

[0086] In the present application, CS-K refers to the compressive stress value of the surface of the strengthened glass, which is mainly generated by the replacement of K ions in the strengthening salt with Na ions in the glass. DOL-Na refers to the depth of ion exchange of Na ions and Li ions in the compressive stress layer of the strengthened glass. DOL-K refers to the depth of ion exchange of K ions in the compressive stress layer of the strengthened glass.

[0087] CS-Na 30 , CS-Na 50 respectively, refer to the compressive stress values at the depth of 30 μm and the depth of 50 μm of the strengthened glass sample after being strengthened by the mixed salt. The stress values at these positions are mainly generated by the replacement of Li ions in the glass with Na ions in the strengthening salt.

[0088] The sandpaper drop performance of the whole machine is measured by a mobile phone controlled drop tester, and the specific test conditions are: 180 mesh sandpaper, 195 g total weight, 60 cm base height, 5 cm increment, 1 time per height, until broken.

[0089] The relationship between the D value of the crack-resistant glass prepared in Examples 1-10 and the sandpaper drop height of 180 mesh sandpaper is plotted as Figure 1 .

[0090] Table 1

[0091]

[0092]

[0093] Table 2

[0094]

[0095] Table 3

[0096]

[0097]

[0098] From the test results, it can be seen that:

[0099] (1) From Example 1 to Example 10, it can be seen that the anti-crack glass of the present application can greatly improve the drop height resistance and the anti-falling ability of the anti-crack glass by optimizing the mass fraction of SiO2, Al2O3, Li2O, Na2O, K2O, MgO, Y2O3 and ZrO2 in the composition for regulating anti-crack glass. The CS-K of the anti-crack glass is ≥950MPa, the CS-Na 30 ≥160MPa, the CS-Na 50 ≥130MPa, the DOL-Na is ≥120μm, and the DOL-K is ≥7μm.

[0100] (2) From Example 1 to Example 10, it can be seen that the anti-crack glass of the present application has a crack resistance factor D = [(CS-Na 30 )-(CS-Na 50 )] / 20μm, and the range of D is 1.6MPa·μm -1 ≤D≤2MPa·μm -1 , and the drop height resistance of the anti-crack glass is ≥120cm. According to Figure 1 it can be seen that the crack resistance factor D of the anti-crack glass is positively correlated with the drop height resistance, that is, the present application improves the performance of the anti-crack glass by regulating and improving the size of the crack resistance factor D.

[0101] (3) From Example 1 and Comparative Example 1, it can be seen that the components of Comparative Example 1 do not fall within the composition range of the present application, the parameters A, B and C are not within the range of the present application, the crack resistance factor D of Comparative Example 1 is <1.6MPa·μm -1 , the anti-falling performance is significantly reduced, the drop height resistance of 180-mesh sandpaper is reduced, and the maximum is only 80cm, and the damage resistance is reduced.

[0102] In summary, the present application improves the drop height resistance and the anti-falling ability of the anti-crack glass by optimizing the mass fraction of SiO2, Al2O3, Li2O, Na2O, K2O, MgO, Y2O3 and ZrO2 in the composition for regulating anti-crack glass.

[0103] The applicant declares that the above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by any person skilled in the art, and all fall within the protection scope and disclosure scope of the present application.

Claims

1. A composition for crack resistant glass, characterized by, The anti-crack glass composition comprises, in oxide form, SiO2, Al2O3, Li2O, Na2O, K2O, MgO, Y2O3 and ZrO2; The mass fraction of Al2O3 is 16wt%-21wt%, the mass fraction of Li2O is 2wt%-6.5wt%, the mass fraction of Na2O is 0.5wt%-4wt%, the mass fraction of K2O is 1wt%-4wt%, the mass fraction of MgO is 1wt%-5wt%, the mass fraction of Y2O3 is 4.5wt%-7wt%, the mass fraction of ZrO2 is 0.5wt%-3.5wt%, and the balance is SiO2, based on the total mass of the anti-crack glass composition being 100wt%; The mass fractions of the components in the anti-crack glass composition satisfy at least one of the following conditions: (i) 3.91≤A=(SiO2-Al2O3) / (MgO+Y2O3+ZrO2)≤5.87; (ii) 0.38≤B=(Li2O-Na2O) / K2O≤2.5; (iii) 0.27≤C=(Y2O3-Na2O) / (ZrO2+MgO)≤0.76; The crack resistance factor of the anti-crack glass ranges from 1.6 MPa μm -1 ≤ D ≤ 2 MPa μm -1 ; The crack resistance factor D = [(CS - Na 30 )-(CS - Na 50 )] / 20 μm, CS - Na 30 is the compressive stress value at the 30 μm depth position of the strengthened glass sample after mixed salt strengthening, CS - Na 50 is the compressive stress value at the 50 μm depth position of the strengthened glass sample after mixed salt strengthening.

2. A crack resistant glass, characterized by, The anti-crack glass comprises the anti-crack glass composition of claim 1.

3. The crack resistant glass according to claim 2, wherein, The CS-K of the anti-crack glass is ≥950MPa, wherein CS-K refers to the compressive stress value of the surface of the strengthened glass.

4. The crack resistant glass according to claim 2, wherein, CS-Na of the anti-crack glass 30 ≥ 160 MPa.

5. The crack resistant glass according to claim 2, wherein, CS-Na of the anti-crack glass 50 ≥ 130 MPa.

6. The crack resistant glass of claim 2, wherein, The DOL-Na of the anti-crack glass is ≥120μm, wherein DOL-Na refers to the depth of lithium-ion exchange in the compressive stress layer of the strengthened glass.

7. The crack resistant glass of claim 2, wherein, The DOL-K of the anti-crack glass is ≥7μm, wherein DOL-K refers to the depth of potassium-ion exchange in the compressive stress layer of the strengthened glass.

8. The crack resistant glass of claim 2, wherein, The anti-crack glass has a drop height resistance of ≥120cm.

9. A method of making a crack resistant glass according to any one of claims 2-8, characterized in that, The preparation method comprises the following steps: Melting and mixing the anti-crack glass composition of claim 1, followed by clarification, homogenization, molding, annealing and chemical strengthening to obtain the anti-crack glass.

10. The method of claim 9, wherein, The molding method comprises any one of float method, slot down-draw method, casting method or overflow method.

11. The preparation method according to claim 9, characterized in that, The chemical strengthening step comprises: S1: using sodium-ion molten salt to strengthen at 430℃-480℃ for 1h-2h; S2: using potassium-ion molten salt to strengthen at 400℃-430℃ for 1h-2h.

12. Use of the crack resistant glass according to any one of claims 2 to 8, characterized in that, The anti-crack glass is used for front and / or back covers of touch display screens, photovoltaic power generation devices, automobile windows, automobile protective glass, pharmaceutical glass containers.

13. Use of the crack resistant glass according to any one of claims 2 to 8, characterized in that, The anti-crack glass is used in the fields of electronic smart terminals and primary packaging.

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