Acid and alkali resistant glass ceramic, chemical reinforced glass ceramic and preparation method thereof

Abstract

The invention discloses acid and alkali resistant microcrystalline glass, chemically strengthened microcrystalline glass and a preparation method thereof. The crystal phase of the acid and alkali resistant microcrystalline glass is selected from one or more of sodium nepheline, nepheline solid solution, triclinic nepheline and zirconium oxide; the ratio of the residual glass phase in the acid and alkali resistant glass ceramic is R, 40% < = R < = 80%, and 10 < = X / R < = 20; x is less than or equal to 8mg / cm < 2 >, and X is the loss weight of the acid and alkali resistant microcrystalline glass in an acid-resistant strength test; 1.5 < = Y / R < = 5; y is less than or equal to 3mg / cm < 2 > and is the alkali-resistant strength test loss weight of the microcrystalline glass; z / R is larger than or equal to 3 and smaller than or equal to 7, Z is smaller than or equal to 4.5 mg / cm < 2 >, and Z is the weight loss of the glass ceramic soaked in a hydrofluoric acid solution. According to the glass ceramic provided by the invention, the composition of the crystal phase contains the sodium nepheline, the triclinic nepheline or the zirconium oxide, so that the glass ceramic has relatively high mechanical strength and chemical stability, the proportion of the crystal phase to a glass phase is controlled, a composite phase structure is formed, and the glass ceramic is endowed with more excellent acid and alkali resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of glass-ceramics, and particularly to an acid- and alkali-resistant glass-ceramic, a chemically strengthened glass-ceramic, and a preparation method thereof. Background Art

[0002] Most of the existing glass-ceramics are lithium aluminosilicate glasses, which have good chemical stability. However, since the preparation of lithium aluminosilicate glasses requires a large amount of lithium salts, the cost of lithium aluminosilicate glasses is relatively high. Using sodium instead of lithium to prepare sodium aluminosilicate glasses has become a research hotspot. However, due to the addition of sodium, the overall change in the electron distribution in the glass-ceramic network will occur, which will affect the structure of the glass, resulting in the chemical stability, especially the acid and alkali resistance, of the prepared glass-ceramic being inferior to that of lithium silicate glass.

[0003] Therefore, the existing technology still needs to be further improved and enhanced. Summary of the Invention

[0004] In view of the above deficiencies of the existing technology, the present invention provides an acid- and alkali-resistant glass-ceramic, a chemically strengthened glass-ceramic, and a preparation method thereof, aiming to solve the problem of poor acid and alkali resistance of the existing sodium aluminosilicate glass.

[0005] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0006] In a first aspect, an acid- and alkali-resistant glass-ceramic, wherein the crystalline phase of the acid- and alkali-resistant glass-ceramic is selected from one or more of nepheline, nepheline solid solution, carnegieite, and zirconia;

[0007] The proportion of the remaining glass phase in the acid- and alkali-resistant glass-ceramic is denoted as R, 40% ≤ R ≤ 80%, and 10 ≤ X / R ≤ 20;

[0008] And X ≤ 8 mg / cm 2 , where X is the weight loss of the acid- and alkali-resistant glass-ceramic in the acid resistance strength test;

[0009] 1.5 ≤ Y / R ≤ 5; and Y ≤ 3 mg / cm 2 , where Y is the weight loss of the glass-ceramic in the alkali resistance strength test;

[0010] 3 ≤ Z / R ≤ 7, and Z ≤ 4.5 mg / cm 2 , where Z is the weight loss of the glass-ceramic when immersed in hydrofluoric acid (HF) solution.

[0011] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the purpose and beneficial effects of the present invention can be better achieved.

[0012] As a preferred technical solution, for the acid- and alkali-resistant glass-ceramics, in terms of molar percentage, the acid- and alkali-resistant glass-ceramics comprise the following components:

[0013] SiO2: 42% to 55%;

[0014] Al2O3: 13% to 25%;

[0015] Na2O: 12% to 25%; Li2O: 1% to 10%; K2O: 0% to 3%;

[0016] MgO: 0 to 3%; CaO: 0% to 3%;

[0017] ZrO2: 0.5% to 5%; P2O5: 0.5% to 4%; TiO2: 0% to 3%;

[0018] B2O3: 0.5% to 8%; Y2O3: 0% to 2% and one or more of SnO2, NaCl, and Sb2O3 with a total of 0.1% to 1.5%;

[0019] The molar percentages of each oxide satisfy one of the following relationships:

[0020] 0.29 ≤ (Na2O + Li2O) / (SiO2 + Al2O3 + B2O3 + TiO2) ≤ 0.51;

[0021] 18% ≤ (Na2O + Li2O + K2O) ≤ 30%;

[0022] 1% ≤ (ZrO2 + TiO2 + P2O5 + Y2O3) ≤ 9%.

[0023] As a preferred technical solution, for the acid- and alkali-resistant glass-ceramics, 0.32 ≤ (Na2O + Li2O) / (SiO2 + Al2O3 + B2O3 + TiO2) ≤ 0.40.

[0024] As a preferred technical solution, for the acid- and alkali-resistant glass-ceramics, when the soaking conditions are hydrochloric acid with a concentration of 5 wt%, a temperature of 95 °C, and a time of 24 h, X ≤ 8 mg / cm 2 .

[0025] As a preferred technical solution, for the acid- and alkali-resistant glass-ceramics, when the soaking conditions are sodium hydroxide with a concentration of 5 wt%, a temperature of 95 °C, and a time of 6 h, Y ≤ 3 mg / cm 2 .

[0026] As a preferred technical solution, for the acid and alkali resistant glass-ceramics, when the acid and alkali resistant glass-ceramics are soaked in a 5wt% concentration hydrofluoric acid (HF) solution at a temperature of 20°C for 20 minutes, X ≤ 4.5 mg / cm 2 .

[0027] As a preferred technical solution, for the acid and alkali resistant glass-ceramics, the average crystal size in the acid and alkali resistant glass-ceramics is greater than 10 nm and less than or equal to 60 nm.

[0028] As a preferred technical solution, for the acid and alkali resistant glass-ceramics, at a thickness of 0.7 mm, the average transmittance of the acid and alkali resistant glass-ceramics at a wavelength of 400 - 750 nm is greater than 89.0%.

[0029] In a second aspect, a method for preparing the acid and alkali resistant glass-ceramics according to the first aspect, which includes:

[0030] Providing a base glass;

[0031] Successively performing a first heat treatment and a second heat treatment on the base glass to obtain the glass-ceramics; the temperature of the first heat treatment is 400 - 650°C and the time is 60 - 480 minutes; the temperature of the second heat treatment is 540 - 850°C and the time is 10 - 180 minutes;

[0032] In a third aspect, a method for preparing chemically strengthened glass-ceramics, the preparation method includes the following steps:

[0033] Placing the acid and alkali resistant glass-ceramics prepared above in a molten salt and soaking for 0.25 - 12 hours to obtain the chemically strengthened glass-ceramics;

[0034] The molten salt is one or a mixture of two of sodium nitrate and potassium nitrate in a molten state at a temperature of 380°C - 480°C.

[0035] In a fourth aspect, an electronic device, which includes: acid and alkali resistant glass-ceramics, chemically strengthened glass-ceramics, and the acid and alkali resistant glass-ceramics and chemically strengthened glass-ceramics are the acid and alkali resistant glass-ceramics and chemically strengthened glass-ceramics as described above.

[0036] Beneficial effects: Compared with the prior art, for the glass-ceramics provided by the present invention, since the crystal phase composition thereof contains nepheline, carnegieite or zirconia, the glass-ceramics have high mechanical strength and chemical stability. By controlling the proportion of the crystal phase and the glass phase, a composite phase structure is formed, endowing the glass-ceramics with more excellent acid and alkali resistance. Description of the Drawings

[0037] Figure 1The weight loss per unit area diagram of the strengthened sheet for each example after standing still for 24 h at 95°C in a hydrochloric acid solution with a mass concentration of 5%, standing still for 20 min at 20°C in a hydrofluoric acid solution with a mass concentration of 10%, and standing still for 6 h at 95°C in a sodium hydroxide solution with a mass concentration of 5%.

[0038] Figure 2 X-ray diffraction pattern of Example 1. Detailed implementation manners

[0039] The present invention provides an acid- and alkali-resistant glass-ceramics, a chemically strengthened glass-ceramics and a preparation method thereof. To make the objectives, technical solutions and effects of the present invention clearer and more definite, the present invention will be further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. Meanwhile, the steps or actions in the method description can also be reordered or adjusted in an obvious manner for those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean a necessary sequence unless it is stated that a certain sequence must be followed. The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequence or technical meaning.

[0041] Term explanation:

[0042] Base glass: A glass that is not subjected to nucleation, crystallization treatment and ion exchange chemical strengthening treatment, which is obtained by uniformly mixing compounds containing various oxides (including silicon dioxide, aluminum oxide, sodium oxide, calcium oxide, etc.), melting at high temperature, and then annealing by one of the forming methods such as the float method, overflow down-drawing method, roll pressing method, and casting method.

[0043] Glass-ceramics: A type of solid composite material that contains both a glass phase and a crystal phase (microcrystalline phase, crystalline phase) and is prepared by subjecting base glass to controlled crystallization treatment with a set target.

[0044] Nucleation: Making the nucleating substances in the base glass grow into tiny crystal nuclei through heat treatment.

[0045] Crystallization: Making the base glass grow into a certain crystal on the basis of crystal nuclei through heat treatment.

[0046] Crystal phase: The microscopic structure of crystallization, which is a general term for the parts composed of a large number of crystalline solid phases.

[0047] Crystallinity: It is used to represent the proportion of the crystalline region in the (chemically strengthened) glass-ceramics, generally according to the volume ratio of the crystalline phase in the whole glass-ceramics.

[0048] Based on the molar percentage of acid- and alkali-resistant glass-ceramics, the components include:

[0049] SiO2: 42% - 55%; Al2O3: 13% - 25%; Na2O: 12% - 25%; Li2O: 1% - 10%; K2O: 0% - 3%; MgO: 0 - 3%; CaO: 0% - 3%;

[0050] ZrO2: 0.5% - 5%; B2O3: 0.5% - 8%; P2O5: 0.5% - 4%; TiO2: 0% - 3%; Y2O3: 0% - 2%; and one or more of SnO2, NaCl, Sb2O3 with a total of 0.1% - 1.5%;

[0051] For the acid- and alkali-resistant glass-ceramics described above, the molar percentage of its oxides satisfies:

[0052] 0.29 ≤ (Na2O + Li2O) / (SiO2 + Al2O3 + B2O3 + TiO2) ≤ 0.51;

[0053] Preferably, 0.32 ≤ (Na2O + Li2O) / (SiO2 + Al2O3 + B2O3 + TiO2) ≤ 0.40;

[0054] At the same time, for the glass-ceramics described above, the molar percentage of its oxides satisfies:

[0055] 18% ≤ (Na2O + Li2O + K2O) ≤ 30%; and / or 1% ≤ (ZrO2 + TiO2 + P2O5 + Y2O3) ≤ 9%. By controlling the content of monovalent oxides in the glass-ceramics, good stability of the glass-ceramics is ensured.

[0056] As one of the main components of the network-forming oxides in the base glass and glass-ceramic materials, SiO2 is one of the important components that form the Si-O tetrahedrons in the main body and build the network structure. Based on the present invention, the molar fraction of SiO2 is 42.0 - 55.0%, preferably 48 - 53%, and can take values such as 45.0%, 46.0%, 47.0%, 48.0%, 49.0%, 50.0%, 51.0%, 52.0%, 53.0%, 54.0%, 55.0% and any component within the range formed by any two of the above values. When the content of SiO2 is too low, the manufactured product of the material has poor devitrification resistance, poor scratch resistance and low hardness. When the content of SiO2 is greater than 52.0%, the melting temperature of the base glass is too high, and it is difficult to control the crystal composition and size after heat treatment;

[0057] Al2O3, as one of the main components of the internal network structure of the base glass and glass-ceramic materials, is also the main component of crystal forms such as nepheline and triclinic nepheline, and can significantly improve the thermal stability and ion exchange performance, and helps to generate the target crystal. Based on the materials involved in the present invention, the molar fraction of Al2O3 is 13.0 - 25%, preferably 15.0 - 23.0%, and can take values such as 13.0%, 14.0%, 15.0%, 16.0%, 17.0%, 18.0%, 19.0%, 20.0%, 21.0%, 22.0%, 23.0%, 24.0%, 25.0% and any value within the range formed by any two of the above components. However, when the content of Al2O3 exceeds 23.5%, it is easy to cause a decrease in transmittance, an increase in high-temperature viscosity, and an increase in melting point, which is not conducive to production.

[0058] Na2O and Li2O are important alkali metals in the glass-ceramics. Both alkali metal oxides are effective glass fluxes and can significantly reduce the melting temperature of the base glass. At the same time, Na + and Li + Due to the characteristics of the two alkali metal elements, their functions in the glass-ceramics of the present invention have their own advantages, among which:

[0059] Na +It is one of the main components of crystalline forms such as nepheline and carnegieite in glass-ceramics, and is also an important element participating in ion exchange during the chemical strengthening process of glass-ceramics materials. However, when the Na2O content is higher than 26.5%, the chemical stability decreases significantly. Therefore, the ideal molar fraction of Na2O is less than or equal to 23.5%. At this time, not only can the melting temperature be maintained within a suitable range, but also good ion exchange characteristics can be ensured. For the materials involved in the present invention, the molar proportion range of Na2O is 12.0 - 25%, preferably 14.0 - 23%, and the specific values can be 12.0%, 13.0%, 14.0%, 15.0%, 16.0%, 17.0%, 18.0%, 19.0%, 20.0%, 21.0%, 22.0%, 23.0%, 24.0%, 25.0% and any value within the range composed of any one or two of the above values.

[0060] Li2O is an oxide with relatively high alkali metal activity and is an external oxide of the glass network. As one of the additives to reduce the high-temperature viscosity of the base glass, it significantly improves the high-temperature fluidity of the base glass. At the same time, Li + In the glass-ceramics materials of the components described in the present invention, it can participate in the ion exchange chemical strengthening reaction to further enhance the mechanical properties of the glass-ceramics. For the glass-ceramics materials involved in the present invention, the molar proportion range of Li2O content is 1.0 - 10.0%, preferably 3.0 - 9.0%. In the present invention, the specific values can be 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5% and 10.0%, and any value within the range composed of any two of the above values.

[0061] K2O is often added to reduce the high-temperature viscosity of the base glass, significantly improve the formability and fluidity of the base glass at high temperatures, and at the same time significantly reduce the crack incidence rate. A small amount of added K2O can slow down the crystallization behavior during glass forming. When the molar ratio of K2O is too high, crystal phases such as potassium feldspar will form, affecting the mechanical strength and optical properties. For the materials involved in the present invention, the molar proportion content range of K2O is 0.0 - 3.0%, preferably 0.0 - 2.5%. In the present invention, the specific values can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 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%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0% and any value within the range composed of any two of the above values.

[0062] As a divalent alkaline earth metal, MgO can effectively break the bridging oxygen bonds of Si-O tetrahedrons inside the base glass. Mg 2+ is conducive to making the glass have a lower refractive index and density. In the present invention, the molar proportion range of the MgO content is 0-3.0%, specifically it can be 0, 0.50%, 1.0%, 1.50%, 2.0%, 2.50%, 3.0% and any value within the range composed of any two of the above values.

[0063] CaO also serves as a divalent alkaline earth metal, which can promote the crystallization ability of the base glass. At the same time, its Ca 2+ is conducive to improving the optical properties such as the refractive index and transmittance of the glass. In the present invention, the molar proportion range of the CaO content is 0.0%-3.0%, specifically it can be selected as 0%, 0.50%, 1.0%, 1.5%, 2.0%, 2.50%, 3.0% and any value within the range composed of any two of the above values.

[0064] As a network modifier oxide of the glass, B2O3 has a relatively large ionic radius and a high coordination number (6.8) for its cations. Generally, it fills the voids in the silicon-oxygen tetrahedron framework. The coordination of its cations rarely changes, and some properties of its oxide can be considered constant values. B2O3 helps to provide a base glass with a low melting temperature. In addition, adding B2O3 to the base glass can also improve the thermal properties of the glass-ceramics and affect the thermal shock performance of the subsequent heat treatment of the glass-ceramics. When the boron in the residual glass is not charge-balanced by alkaline oxides or divalent cation oxides, the boron will be in a triangular-coordination state (or triply coordinated boron), opening the structure of the glass, and the network around these triply coordinated borons is not as rigid as the tetrahedral coordination (or quadruply coordinated) boron. The presence of boron in the residual glass (and base glass) of the glass-ceramics will reduce the viscosity of the residual glass (or base glass), which promotes the growth of nepheline and microcline crystals, especially the growth of larger crystals with a higher aspect ratio. Generally speaking, the amount of boron should be controlled to maintain the chemical durability and mechanical strength of the glass-ceramics. Too high or too low B2O3 content will make the chemical resistance of the glass-ceramics material formed after nucleation and crystallization of the base glass unstable. The molar proportion range of the B2O3 content in the glass-ceramics involved in the present invention is 0.5-8.0%, preferably 1.0-7.0%, specifically it can take values of 0.5%, 1.0%, 3.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5% and 8.0% and any value within the range composed of any two of the above values.

[0065] In the base glasses and glass-ceramics described herein, it has been found that ZrO₂ can improve the stability of the glass by significantly reducing devitrification during formation and lowering the liquidus temperature. At high temperatures, ZrSiO₄ can form the main liquidus phase, which significantly reduces the liquidus viscosity. When the glass contains no more than 2 mol% of ZrO₂, a transparent glass can be formed. At the same time, the tetragonal phase of ZrO₂ can increase the strength and toughness of the glass-ceramic; in the present invention, the molar proportion range of ZrO₂ is 0.5-5.0%, specifically it can be 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0% and any value within the range composed of any two of the above values.

[0066] P₂O₅ can promote the phase separation and overall crystallization ability of the base glass. If the concentration of P₂O₅ is too low, the base glass does not crystallize, and only crystals are formed from the surface inward at higher temperatures and low viscosities. If the concentration of P₂O₅ is too high, it will be difficult to control devitrification when cooling during the formation of the base glass; in the present invention, the molar proportion range of P₂O₅ is 0.5-4.0%, specifically it can be 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5% and 4.0% and any value within the range composed of any two of the above values.

[0067] In the base glasses and glass-ceramics described herein, Ti in TiO₂ 4+ body-centered octahedral structural unit, and 6 O 2- coordinated in six directions, containing 1 Ti 4+ oxygen octahedron can effectively promote the crystal nucleus growth during the nucleation and crystallization heat treatment of the base glass, and at the same time improve the stability of the glass; the introduction of TiO₂ effectively promotes the precipitation of crystal nuclei during the nucleation process. At the same time, the introduction of TiO₂ easily causes phase separation of the base glass, resulting in crystallization and affecting the formation of the glass. In the present invention, the molar proportion range of TiO₂ is 0-3.0%, specifically it can be 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% and any value within the range composed of any two of the above values.

[0068] Y₂O₃ is also a rare metal oxide, which is a network modifier oxide and affects the thermal expansion coefficient of the glass. Although Y 3+Outside the network, due to its high electric field strength, it accumulates the surrounding silicon-oxygen tetrahedrons and hinders the expansion of the glass skeleton caused by thermal vibration. In the present invention, the molar proportion range of Y2O3 content is between 0 and 2%, and it can be 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0% and any value within the range composed of any two of the above values.

[0069] The present invention also contains 0.1-1.5% of a clarifying agent, and the clarifying agent includes one or more of SnO2, NaCl, and Sb2O3; the clarifying agent can homogenize the various oxides of the base glass in a molten state and uniformly distribute the various oxides in the glass body. In the present invention, the molar proportion range of the content of the clarifying agent is 0.1-1.0%, and specifically it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5% and any value within the range composed of any two of the above values.

[0070] Based on the same inventive concept, the present invention also provides a method for preparing acid and alkali resistant glass ceramics, including:

[0071] S10. Provide the chemically strengthened glass ceramic body.

[0072] Specifically, according to SiO2: 42% - 55%; Al2O3: 13% - 25%; Na2O: 12% - 25%; Li2O: 1% - 10%; K2O: 0% - 3%; MgO: 0 - 3%; CaO: 0% - 3%; ZrO2: 0.5% - 5%; P2O5: 0.5% - 4%; TiO2: 0% - 3%; B2O3: 0.5% - 8%; Y2O3: 0% - 2% and a total of 0.1% - 1.5% of SnO2, NaCl, Sb2O3, weigh each raw material and mix them evenly, and use one of the forming methods such as overflow method, float method, roll pressing method or casting method to obtain the base glass; perform nucleation and crystallization heat treatment on the base glass to obtain the glass ceramic body; the glass ceramic undergoes deep processing procedures such as cutting, grinding and polishing, and ion exchange chemical strengthening to obtain a transparent chemically strengthened glass ceramic.

[0073] S20, performing a first heat treatment and a second heat treatment on the base glass in sequence to obtain the microcrystalline glass; the first heat treatment temperature is 400-650°C, the time is 60-480 minutes, and the second heat treatment temperature is 540-850°C, the time is 10-180 minutes. By controlling the temperatures of the two heat treatments within the above range, the obtained microcrystalline glass has good chemical stability.

[0074] In one implementation of the present invention, after obtaining the microcrystalline glass, it also includes a chemical strengthening step: (1) placing the microcrystalline glass sheet in a mixed molten salt of NaNO3 and KNO3 in a molten state at a temperature of 450°C and soaking it for 8 hours to obtain a first chemically strengthened microcrystalline glass; (2): placing the once strengthened microcrystalline glass obtained in step (1) in a 100% KNO3 molten salt in a molten state at a temperature of 390°C and soaking it for 45 minutes to obtain a chemically strengthened microcrystalline glass.

[0075] For some production examples, the basic glass used for preparation can be prepared by rolling method, continuous melting casting method, float method or overflow method. The basic preparation of the microcrystalline glass of the present invention is prepared by casting method.

[0076] The composition of the basic glass is shown in Table 1.

[0077] Table 1 Chemical composition of basic products

[0078]

[0079]

[0080] The corresponding compounds containing the oxide components of the above-mentioned embodiments 1-7 are mixed uniformly, melted in a platinum-rhodium alloy dryer at a temperature of 1600°C for 4 hours, stirred during the melting process, and then poured into a mold composed of steel bars and steel blocks in a high-temperature molten state at 1450°C to form a rectangular glass brick, and annealed to obtain a block-shaped basic glass brick.

[0081] The basic glass bricks are then placed in a precision crystallization furnace (or tunnel kiln) for nucleation and crystallization heat treatment to obtain microcrystalline glass, wherein the operating parameters of nucleation and crystallization temperature and time are shown in Table 2.

[0082] Table 2 Heat treatment parameters of products

[0083]

[0084] Testing Equipment and Testing Method for Glass-Ceramics after Crystallization of Base Glass: XRD Testing: Grind the glass-ceramics sheet into fine glass powder with a grinding machine, and conduct testing through Rigaku Smart lab X-ray diffraction (XRD) under the conditions that the diffraction angle range 2θ used for testing is from 10° to 80°, the scanning speed is 10° / min, the working voltage is 40 kV, and the working current is 30 mA, to obtain the XRD diffraction peak curve. Then use the professional processing software Jade software to analyze the XRD diffraction data, analyze the type and size of crystal phases contained in the glass-ceramics and the crystal proportion, and at the same time fit the diffraction peak curve to obtain the total content of crystal phases in the glass-ceramics.

[0085] Shape, cut, grind, and polish the glass-ceramics after crystallization heat treatment to obtain glass-ceramics sheets with a size of 50 mm * 50 mm * 0.65 mm, and immerse them in a mixed molten salt of KNO3 and NaNO3 for chemical strengthening to obtain chemically strengthened glass-ceramics. Specifically, the chemical strengthening process parameters are shown in Table 3.

[0086] Conduct various optical index and mechanical property index tests on the chemically strengthened glass-ceramics. The methods are as follows (in this invention, at least 10 samples with the above size specifications are taken for testing and the average value is taken): 1. Transmittance testing: Use an ultraviolet-visible spectrophotometer, and refer to the GB / T40415 standard to test its transmittance in the wavelength range of 380 nm to 800 nm (i.e., visible light transmittance);

[0087] 2. Acid and alkali resistance

[0088] 1) Stand still in a hydrochloric acid solution with a mass concentration of 5% at 95 °C for 24 h (abbreviated as "HCl-5%-95 °C-24 h");

[0089] 2) Stand still in a hydrofluoric acid solution with a mass concentration of 10% at 20 °C for 20 min (abbreviated as "HF-10%-20 °C-20 min");

[0090] 3) Stand still in a sodium hydroxide solution with a mass concentration of 5% at 95 °C for 6 h (abbreviated as "NaOH-5%-95 °C-6 h")

[0091] 3. Chemical stability evaluation method: Use an analytical balance to weigh the mass of the glass sample before and after the acid and alkali resistance test, calculate the weight loss per unit area, and use this to measure the acid and alkali resistance of the glass sample. Specifically, use an analytical balance to weigh the mass of the glass sample before and after the acid and alkali resistance test as m0 and m1 respectively, and the area of the glass sample is s, then the weight loss per unit area x = (m0 - m1) / s.

[0092] 4. Chemical strengthening property testing: CS, DOL, etc.

[0093] CS: It refers to that after chemical strengthening of the glass, the smaller alkali metal ions are replaced by larger alkali metal ions. Due to the jamming effect of the larger alkali metal ions, compressive stress is generated on the glass surface, which is obtained by testing with a stress meter and the unit is Mpa.

[0094] DOL: Depth of compressive stress, or depth of compressive stress layer, refers to the distance from any surface of the glass-ceramic to the position where the compressive stress close to that surface is zero, which is obtained by testing with a stress meter and the unit is μm. In this patent, the stress meter SLP-2000 of Zheyuan in Japan is used, and the test is carried out with reference to the test method of the national standard GB-T 18144-2008 "Test Method for Glass Stress" to test the depth of compressive stress layer (DOL) and surface compressive stress (CS) of chemically strengthened glass-ceramics. Table 3 Chemical strengthening parameters and performance indexes of chemically strengthened glass-ceramics

[0095]

[0096] Combined with the corresponding conclusions given in the attached drawings, it can be seen that the acid and alkali resistance of the glass-ceramics is affected to a certain extent by the content of the residual glass phase. The higher the content of the residual glass phase, the worse the acid and alkali resistance. From Examples 3 and 4, it can be seen that adding yttrium oxide can increase its acid and alkali resistance when the content of the residual glass phase is similar.

[0097] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all these improvements and transformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. An acid- and alkali-resistant glass-ceramic, characterized in that: The crystal phase of the acid-alkali resistant microcrystalline glass is selected from one or more of sodium nepheline, nepheline solid solution, triclinic nepheline and zirconium oxide; The remaining glass phase ratio in the acid-alkali resistant micro-ceramic glass is R, 40%≤R≤80%, and 10≤X / R≤20; And X≤8mg / cm 2 , X is the weight loss of the acid-alkali resistant glass-ceramics in the acid resistance strength test; 1.5≤Y / R≤5; and Y≤3mg / cm 2 , Y is the weight loss of the microcrystalline glass in the alkali resistance strength test; 3≤Z / R≤7, and Z≤4.5mg / cm 2 , Z is the weight loss of the microcrystalline glass when immersed in hydrofluoric acid solution.

2. The acid- and alkali-resistant glass-ceramics according to claim 1, characterized in that: In terms of molar percentage, the acid-alkali resistant glass-ceramics includes the following components: SiO2: 42%~55%; Al2O3: 13%~25%; Na2O: 12% ~ 25%; Li2O: 1% ~ 10%; K2O: 0% ~ 3%; MgO: 0% ~ 3%; CaO: 0% ~ 3%; ZrO2: 0.5% ~ 5%; P2O5: 0.5% ~ 4%; TiO2: 0% ~ 3%; B2O3: 0.5% to 8%; Y2O3: 0% to 2% and one or more of SnO2, NaCl, Sb2O3 with a total of 0.1% to 1.5%; The molar percentage of each oxide satisfies one of the following relationships: 0.29≤(Na2O+Li2O) / (SiO2+Al2O3+B2O3+TiO2)≤0.51; 18%≤(Na2O+Li2O+K2O)≤30%; 1%≤(ZrO2+TiO2+P2O5+Y2O3)≤9%.

3. The acid- and alkali-resistant glass-ceramics according to claim 1, characterized in that: 0.32≤(Na2O+Li2O) / (SiO2+Al2O3+B2O3+TiO2)≤0.

40.

4. The acid- and alkali-resistant glass-ceramics according to claim 1, characterized in that: The acid-alkali resistant microcrystalline glass is immersed in a 5wt% hydrochloric acid solution at 95°C for 24h, and X≤8mg / cm 2 .

5. The acid- and alkali-resistant glass-ceramics according to claim 1, characterized in that: The acid-alkali resistant microcrystalline glass is immersed in a 5wt% sodium hydroxide solution at 95°C for 6 hours, and Y≤3mg / cm 2 .

6. The acid- and alkali-resistant glass-ceramics according to claim 1, characterized in that: The acid-alkali resistant microcrystalline glass is immersed in a 10wt% hydrofluoric acid HF solution at a temperature of 20°C for 20 minutes, and Z≤4.5mg / cm 2 .

7. The acid- and alkali-resistant glass-ceramics according to any one of claims 1 to 6, characterized in that: The average crystal size of the acid-alkali resistant microcrystalline glass is greater than 10 nm and less than or equal to 60 nm. At a thickness of 0.7 mm, the average transmittance of the acid-alkali resistant microcrystalline glass at a wavelength of 400 to 750 nm is greater than 89.0%.

8. A method for preparing the acid- and alkali-resistant microcrystalline glass according to claim 1, characterized in that: include: Provide basic glass; The base glass is subjected to a first heat treatment and a second heat treatment in sequence to obtain the microcrystalline glass; the first heat treatment temperature is 400-650° C., the time is 60-480 min, and the second heat treatment temperature is 540-850° C., the time is 10-180 min; In terms of mole percentage, the base glass comprises the following components: SiO2: 42%~55%; Al2O3: 13%~25%; Na2O: 12% ~ 25%; Li2O: 1% ~ 10%; K2O: 0% ~ 3%; MgO: 0% ~ 3%; CaO: 0% ~ 3%; ZrO2: 0.5% ~ 5%; P2O5: 0.5% ~ 4%; TiO2: 0% ~ 3%; B2O3: 0.5% to 8%; Y2O3: 0% to 2% and one or more of SnO2, NaCl, Sb2O3 with a total of 0.1% to 1.5%; The molar percentage of each oxide satisfies one of the following relationships: 0.29≤(Na2O+Li2O) / (SiO2+Al2O3+B2O3+TiO2)≤0.51; 18%≤(Na2O+Li2O+K2O)≤30%; 1%≤(ZrO2+TiO2+P2O5+Y2O3)≤9%.

9. A method for preparing chemically strengthened glass-ceramics, characterized in that: The preparation method comprises the following steps: The acid- and alkali-resistant microcrystalline glass prepared according to claim 8 is placed in a molten salt and soaked for 0.25 to 12 hours to obtain the chemically strengthened microcrystalline glass; The molten salt is one or a mixture of sodium nitrate and potassium nitrate in a molten state at a temperature of 380° C. to 480° C.

10. An electronic device, characterized in that: include: Acid- and alkali-resistant glass-ceramics and chemically strengthened glass-ceramics, wherein the acid- and alkali-resistant glass-ceramics and chemically strengthened glass-ceramics are the acid- and alkali-resistant glass-ceramics described in any one of claims 1 to 7 or the chemically strengthened glass-ceramics prepared by the preparation method described in claim 9.

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