Acid and alkali resistant glass ceramic, preparation method thereof and kitchen stove or kitchen appliance

Abstract

The invention belongs to the field of glass ceramics, and particularly relates to acid and alkali resistant glass ceramics, a preparation method thereof and kitchen stoves or kitchen appliances. The glass ceramic comprises the following chemical components in mole percent: 69.5 mol% to 71.5 mol% of SiO2, 13 mol% to 14.2 mol% of Al2O3, 7.4 mol% to 8.8 mol% of Li2O, 0.37 mol% to 0.55 mol% of P2O5, 0.05 mol% to 0.15 mol% of SnO2, less than 0.1 mol% of As2O3, Sb2O3, B2O3 and F, and less than 2.2 of (SiO2 + Al2O3) / (100 * P2O5) which is more than 1.65 and less than 2.2, based on the total mass of crystals contained in the microcrystalline glass, the ratio of the mass content of the hydrothermal quartz solid solution to the mass content of the high quartz solid solution is 1.2-9.3%; the high-temperature founding processability and the acid and alkali corrosion resistance can be improved, the thermal expansion is reduced, and the cold and heat sudden change resistance is improved.

Description

Technical Field

[0001] This application belongs to the technical field of glass-ceramics, and specifically relates to acid- and alkali-resistant glass-ceramics, their preparation methods, and kitchen cooktops or kitchen appliances. Background Art

[0002] Glass-ceramics, also known as glass ceramics, are a special type of glass material that contains a large number of micro-nano crystals and residual glass phases inside. As an important branch of glass-ceramics, the main crystal phase components of LAS-based glass-ceramics are Li 2 O-Al 2 O 3 -SiO 2 , which have unique low expansion, high strength, high temperature resistance and other characteristics, can withstand the sudden temperature change from 800°C to room temperature, and even can withstand the temperature change from 850°C to room temperature; they have good impact resistance, with an impact strength of 0.5J spring hammer, and a bending strength higher than 100MPa, significantly stronger than ordinary glass. Therefore, LAS glass-ceramics are ideal materials for applications such as kitchen cooktops and household appliance panels.

[0003] However, the kitchen environment is extremely complex. For the glass covers used on cooktops and kitchen appliances, in addition to the basic requirements of resisting thermal and mechanical shocks, they should also have excellent resistance to acid and alkali erosion. First of all, acidic substances are common substances faced by cooktops or household appliances. Among the ingredients and seasonings used in cooking, there are various acidic substances, such as seasonings like vinegar and ketchup. During the cooking process, some acidic liquids or residues are very likely to splash onto the glass-ceramic panel. After long-term contact, it will damage the surface of the glass-ceramic panel and form various spots. Secondly, alkaline substances are even more worthy of attention, especially during the cleaning stage after cooking. Common scenarios include cleaning residual objects such as oil stains and grease. Hot alkaline cleaning agents have better cleaning effects; especially when there are scorched substances attached to the panel surface due to long-term heating, strong alkaline cleaning agents are the first choice, and the higher the water temperature of the cleaning agent, the better the cleaning effect.

[0004] It is common knowledge in this field that glass-based materials, compared with metal materials, have the characteristic of being acid-resistant but not alkali-resistant. In the field of glass materials, LAS glass-ceramics have better acid and alkali resistance than ordinary glass, but they are still insufficient in dealing with acid and alkali resistance in a heating environment, especially hot strong alkaline solutions, which are very likely to cause "matting" on the surface of the LAS glass-ceramic panel, and the surface of the panel is slightly corroded and loses its luster. Although these defects do not affect the safety performance of the glass-ceramic panel, the appearance is damaged and the user experience is greatly reduced.

[0005] The current glass-ceramics have limited acid and alkali resistance and are difficult to meet the usage requirements of kitchen cooktops and household appliance panels.

[0006] It should be noted that the content of this part of the present application only provides the background technology related to the present application, and does not necessarily constitute the prior art or the well-known technology. Summary of the Invention

[0007] The purpose of the present invention is to overcome the defects that the existing glass-ceramics have limited acid and alkali resistance and are difficult to meet the use requirements of kitchen stove tops and household appliance panels, and to provide acid- and alkali-resistant glass-ceramics, their preparation methods, and kitchen cookers or kitchen appliances, which have significantly improved acid and alkali resistance, can meet the use requirements of kitchen stove tops and household appliance panels, and protect the appearance of the glass-ceramic panel during use.

[0008] To achieve the above purpose, in the first aspect, the present application provides an acid- and alkali-resistant glass-ceramic, the chemical composition of which includes SiO in mole percentage 2 : 69.5 mol% - 71.5 mol%, Al 2 O 3 : 13 mol% - 14.2 mol%, Li 2 O: 7.4 mol% - 8.8 mol%, P 2 O 5 : 0.37 mol% - 0.55 mol%, SnO 2 : 0.05 mol% - 0.15 mol%, As 2 O 3 +Sb 2 O 3 +B 2 O 3 +F < 0.1 mol%, 1.65 < (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5 ) < 2.2;

[0009] Based on the total mass of the crystals contained in the glass-ceramic, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 1.2% - 9.3%;

[0010] Perform an acid erosion test on the glass-ceramic, and the erosion amount ≤ 15 mg / dm 2 , and the detection conditions of the acid erosion test include: the erosion solution is a HCl solution with a concentration of 6 mol / L, and the erosion is carried out for 6 h under boiling conditions; perform an alkali erosion test on the glass-ceramic, and the erosion amount ≤ 175 mg / dm 2 , and the detection conditions of the alkali erosion test include: the erosion solution is a Na 2 CO 3The solution is mixed with an equal volume of a NaOH solution with a concentration of 1 mol / L and etched under boiling conditions for 3 h.

[0011] In some preferred embodiments, based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 2.5% to 8.2%. Further preferably, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 2.8% to 7.4%.

[0012] In some preferred embodiments, 1.75 < (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5 ) < 2.2. Further preferably, 1.9 < (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5 ) < 2.2.

[0013] In some preferred embodiments, its chemical composition in mole percentages further includes: 1.5 < (CaO + 0.4×MgO + 1.2×ZnO) / [0.5×(BaO + SrO) + 1×Na 2 O + 0.2×K 2 O] < 2.4.

[0014] Preferably, 1.6 < (CaO + 0.4×MgO + 1.2×ZnO) / [0.5×(BaO + SrO) + 1×Na 2 O + 0.2×K 2 O] < 2.4. Further preferably, 2 < (CaO + 0.4×MgO + 1.2×ZnO) / [0.5×(BaO + SrO) + 1×Na 2 O + 0.2×K 2 O] < 2.4.

[0015] In some preferred embodiments, its chemical composition in mole percentages further includes: CaO: 0.05 mol% to 0.50 mol%, MgO: 0.90 mol% to 1.40 mol%, ZnO: 0.95 mol% to 1.45 mol%, SrO + BaO: 0.55 mol% to 0.80 mol%, K 2 O + Na 2 O: 0.6 mol% to 1.0 mol%.

[0016] In some preferred embodiments, its chemical composition further includes, in mole percentage: 0.71 < (TiO 2 + ZrO 2 ) / (R 2 O + RO) < 0.89, where R 2 O represents the oxide of monovalent alkali metal elements other than Li 2 O, and RO represents the oxide of divalent metal elements.

[0017] Preferably, 0.73 < (TiO 2 + ZrO 2 ) / (R 2 O + RO) < 0.87, and more preferably, 0.75 < (TiO 2 + ZrO 2 ) / (R 2 O + RO) < 0.85.

[0018] In some preferred embodiments, its chemical composition further includes, in mole percentage: TiO 2 : 2.3 mol% - 2.65 mol%, ZrO 2 : 0.65 mol% - 0.95 mol%.

[0019] In a second aspect, the present invention provides a method for preparing acid- and alkali-resistant glass ceramics, including: proportioning materials according to the components contained in the glass ceramics described in the first aspect, mixing and melting, then forming, and thereafter performing crystal growth.

[0020] In a third aspect, the present invention provides a kitchen stove or kitchen appliance, which includes the glass ceramics described in the first aspect and / or the glass ceramics prepared by the preparation method described in the second aspect.

[0021] The inventors found that in LAS glass ceramics, the crystal phase has better resistance to acids and alkalis than the residual glass phase. More unexpectedly, the anti-erosion behavior of hydrothermal quartz to acids and alkalis is quite different from that of high quartz. First, there are significant differences in their crystal morphologies. The grain size of the high quartz solid solution is relatively small, mostly 20 nm - 60 nm. During the high-temperature heat treatment process, as the holding time prolongs or the crystallization temperature increases, the high quartz solid solution gradually transforms into the hydrothermal quartz solid solution. The process of crystal phase transformation is the process of crystal aggregation and growth. As the fine grains aggregate, the specific surface area of the crystal decreases, and the crystal surface becomes more stable; and during the crystal phase transformation process, more silica participates in crystallization. These factors result in that when at the solid-liquid interface in an acidic or alkaline solution, hydrothermal quartz has higher erosion resistance. Therefore, appropriately promoting the precipitation of the hydrothermal quartz crystal phase is of great help in improving the acid and alkali resistance of LAS glass ceramics.

[0022] However, the inventors also found that an excessive amount of hydrothermal quartz phase instead caused great damage to the alkali resistance. This is because during the transformation from high quartz to hydrothermal quartz, as silica further participates in crystallization, the crystal cell structure undergoes a fundamental change. The high quartz solid solution is in the hexagonal crystal system (Hexagonal), and the unit cell parameters are approximately The hydrothermal quartz solid solution is in the orthorhombic crystal system (Orthorhombic), and the unit cell parameters are approximately The unit cell of the hydrothermal quartz solid solution is significantly larger. The packing coefficient of the orthorhombic crystal system of hydrothermal quartz is smaller than that of the hexagonal crystal system of high quartz. Therefore, there are fast ion migration channels inside hydrothermal quartz, and the ion migration rate of small-radius cations in hydrothermal quartz is significantly higher than that of high quartz. Under the action of the alkali solution OH - , elements such as Li, Mg, and Zn in the glass-ceramics are more likely to detach from the crystal phase and form precipitates in the external solution. The ion concentration difference on both sides of the solid-liquid interface will cause the elements in hydrothermal quartz to continuously precipitate into the external solution. This precipitation rate is significantly higher than that of high quartz crystals, ultimately leading to a substantial increase in the mass loss per unit surface.

[0023] In addition, as is well known to those skilled in the art, the thermal expansion coefficient of hydrothermal quartz is much higher than that of the high quartz phase. An excessive proportion of the hydrothermal quartz phase greatly damages the linear thermal expansion coefficient of LAS glass-ceramics and is likely to cause problems such as board explosion during the heating operation state, which should be avoided.

[0024] Based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of the hydrothermal quartz solid solution to the mass content of the high quartz solid solution is 1.2% - 9.3%, which can improve the acid and alkali resistance of the glass-ceramics and maintain a low thermal expansion coefficient (CTE40 - 700°C < 0.5 ppm / °C).

[0025] In LAS glass-ceramics, in addition to the crystal phase structure and composition affecting the acid and alkali resistance, various oxide components play a crucial role in the acid and alkali resistance of the glass-ceramics. Their roles are reflected in two aspects: First, affecting the acid and alkali resistance of the residual glass phase; second, affecting the crystallization process. Thus, the acid and alkali resistance of LAS glass-ceramics is changed. At the same time, the LAS glass-ceramics of the present invention are prepared by processes such as high-temperature melting and rolling, and these processes impose restrictions on the selection range of oxides. In terms of the end use, the rigid constraints on general requirements such as low expansion and high strength also impose necessary restrictions on the selection range of oxides.

[0026] SiO 2 can play a role in improving the acid and alkali resistance of the glass-ceramics, but it has a high melting point and is difficult to melt. Al 2 O 3It can also play a role in improving the acid and alkali resistance, but it will increase the viscosity of the glass-ceramics, which is likely to cause difficulties in high-temperature melting and too rapid hardening during the rolling process. SiO 2 and Al 2 O 3 The addition of increases the difficulty of melting and forming while improving the acid and alkali resistance. The addition of P 2 O 5 can reduce the high-temperature viscosity, improve the solubility of high-melting-point substances such as alumina and zirconia in the glass, and avoid defects such as raw materials and impurities during the high-temperature melting process. However, it is likely to cause a decrease in the acid and alkali resistance of the glass-ceramics. When the SiO 2 content is 69.5 mol% to 71.5 mol%, the Al 2 O 3 content is 13 mol% to 14.2 mol%, and the P 2 O 5 content is 0.37 mol% to 0.55 mol%, making 1.65 < (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5 ) < 2.2 can improve the acid and alkali erosion resistance of the glass-ceramics while keeping the viscosity of the glass-ceramics within a range suitable for high-temperature melting and forming processing.

[0027] For the glass-ceramics of the present invention, the SiO 2 content is 69.5 mol% to 71.5 mol%, the Al 2 O 3 content is 13 mol% to 14.2 mol%, the Li 2 O content is 7.4 mol% to 8.8 mol%, the P 2 O 5 content is 0.37 mol% to 0.55 mol%, the SnO 2 content is 0.05 mol% to 0.15 mol%, As 2 O 3 +Sb 2 O 3 +B 2 O 3 +F < 0.1 mol%, 1.65 < (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5) < 2.2, and based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 1.2% - 9.3%. Through the synergistic effects in multiple aspects above, the acid and alkali erosion resistance of the glass-ceramics can be improved while maintaining the high-temperature melting and processing properties of the glass-ceramics. The glass-ceramics are tested for acid erosion resistance, and the erosion amount ≤ 15 mg / dm 2 , and the glass-ceramics are tested for alkali erosion resistance, and the erosion amount ≤ 175 mg / dm 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a crystal phase test diagram of the glass-ceramics of Example 1.

[0030] Figure 2 It is a linear thermal expansion coefficient test curve diagram of the glass-ceramics of the examples and comparative examples from 40°C to 700°C. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0032] The inventors of the present invention have found that in the prior art, the acid and alkali resistance of glass-ceramics is limited. When used in kitchen stove tops, household appliance panels and other occasions, since they are likely to come into contact with acidic or alkaline seasonings or cleaning agents containing acidic or alkaline substances, the appearance is easily damaged, affecting the use experience, and it is difficult to meet the use requirements of kitchen stove tops and household appliance panels.

[0033] In a first aspect, the present invention provides an acid and alkali resistant glass-ceramics, whose chemical composition includes SiO in mole percentage 2 : 69.5 mol% - 71.5 mol%, Al 2 O 3 : 13 mol% - 14.2 mol%, Li 2 O: 7.4 mol% - 8.8 mol%, P2 O 5 : 0.37 mol% to 0.55 mol%, SnO 2 : 0.05 mol% to 0.15 mol%, As 2 O 3 +Sb 2 O 3 +B 2 O 3 +F < 0.1 mol%, 1.65 < (SiO 2 +Al 2 O 3 ) / (100 × P 2 O 5 ) < 2.2;

[0034] Based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 1.2% to 9.3%;

[0035] The acid resistance erosion test is carried out on the glass-ceramics, and the erosion amount ≤ 15 mg / dm 2 , and the detection conditions of the acid resistance erosion test include: the erosion solution is a HCl solution with a concentration of 6 mol / L, and the erosion is carried out for 6 h under boiling conditions; the alkali resistance erosion test is carried out on the glass-ceramics, and the erosion amount ≤ 175 mg / dm 2 , and the detection conditions of the alkali resistance erosion test include: the erosion solution is a solution obtained by mixing an equal volume of a Na 2 CO 3 solution and a NaOH solution with a concentration of 1 mol / L, and the erosion is carried out for 3 h under boiling conditions.

[0036] The inventors found that the high quartz solid solution has fine grains, and the size is mostly 20 nm to 60 nm. After the high quartz solid solution is transformed into the hydrothermal quartz solid solution, the crystals agglomerate and grow, the specific surface area decreases, and the crystal surface is more stable; the high quartz solid solution is hexagonal (Hexagonal), and the unit cell parameter is about The hydrothermal quartz solid solution is orthorhombic (Orthorhombic), and the unit cell parameter is about The unit cell of the hydrothermal quartz solid solution is significantly larger. The packing coefficient of the orthorhombic system of hydrothermal quartz is smaller than that of the hexagonal system of high quartz. There are fast ion migration channels inside the hydrothermal quartz. The ion migration rate of the small-radius cations in the hydrothermal quartz is significantly higher than that of the high quartz. In the alkali solution OH -Under the action of [specific factor], elements such as Li, Mg, and Zn in the glass-ceramics are more likely to dissociate from the crystal phase and form precipitates in the external solution. The ion concentration difference on both sides of the solid-liquid interface will cause the elements in the hydrothermal quartz to continuously precipitate into the external solution; appropriately increasing the content of the hydrothermal quartz solid solution in the crystal can improve the acid and alkali resistance of the glass-ceramics. However, when the content of the hydrothermal quartz solid solution is too high, it will reduce the acid and alkali resistance of the glass-ceramics. Based on the total mass of the crystals contained in the glass-ceramics, when the mass content ratio of the hydrothermal quartz solid solution to the high quartz solid solution is 1.2% - 9.3%, the acid and alkali resistance of the glass-ceramics can be improved. When the ratio is lower than 1.2%, due to the instability of the crystal surface, the acid and alkali resistance of the glass-ceramics is affected. When the ratio is higher than 9.3%, due to the significantly higher ion migration rate of the small-radius cations in the hydrothermal quartz than that in the high quartz, the alkali resistance of the glass-ceramics is affected.

[0037] Li 2 O is a good flux. During the high-temperature melting process, it reduces the high-temperature viscosity, promotes the homogenization and clarification of the glass melt, and is also beneficial to high-temperature calendering. During the high-temperature crystallization process, Li 2 O can also reduce the crystallization temperature of high quartz and hydrothermal quartz, promote crystallization, and thus reduce the expansion coefficient of the glass-ceramics. In the present invention, by making the Li 2 O content of the glass-ceramics be 7.4 mol% - 8.8 mol%, it can reduce the high-temperature viscosity, reduce the high-temperature melting difficulty, inhibit the damage of the forming roller, reduce the crystallization temperature, while reducing the cost and preventing the formation of crystal phases such as lithium disilicate, which leads to an increase in the thermal expansion coefficient of the glass-ceramics and fails to meet the requirements of thermal shock resistance. If the Li 2 O content is lower than 7.4 mol%, it will cause the viscosity of the glass-ceramics to be too high, bringing problems such as difficult melting, fast damage of the roller, and high crystallization temperature, and the difficulty of industrial preparation is large. If the Li 2 O content is higher than 8.8 mol%, the production cost is uneconomical, and the glass-ceramics are likely to fail to meet the requirements of thermal shock resistance.

[0038] SiO 2 has a relatively high melting point. When the SiO 2 content is 69.5 mol% - 71.5 mol%, it can reduce the melting difficulty while reducing the thermal expansion coefficient, improve the thermal shock resistance of the glass-ceramics, and improve the acid and alkali resistance. If the SiO 2 content is lower than 69.5 mol%, it will affect the acid and alkali resistance and thermal shock resistance of the glass-ceramics. If the SiO 2 content is higher than 71.5 mol%, due to the high melting point of SiO 2 and difficult melting, it will lead to an increase in the melting difficulty and processing difficulty of the glass-ceramics.

[0039] Al 2 O3 The content is 13 mol% - 14.2 mol%, which can improve the hardness and acid and alkali resistance of the glass-ceramics while reducing the viscosity of the glass melt, lowering the difficulty of high-temperature melting, reducing the bubbles in the glass melt, inhibiting crystallization before rolling, preventing excessive hardening during calendering, and inhibiting the formation of adverse crystal phases such as mullite during the high-temperature crystallization process, resulting in an increase in the thermal expansion coefficient. Al 2 O 3 If the content is lower than 13 mol%, it will affect the acid and alkali resistance of the glass-ceramics. Al 2 O 3 If the content is higher than 14.2 mol%, it is likely to cause high viscosity, difficult high-temperature melting, and inability to remove bubbles; the hardening during the calendering process is too fast, making it impossible to roll to the specified thickness, or there may be crystallization before rolling, resulting in warping, deformation of the flat plate, and rapid wear of the roller rods; during the high-temperature crystallization process, adverse crystal phases such as mullite are formed, leading to an increase in the thermal expansion coefficient.

[0040] P 2 O 5 The content is 0.37 mol% - 0.55 mol%, which can reduce the high-temperature viscosity, improve the solubility of high-melting-point substances such as alumina and zirconia in the glass, avoid defects such as raw materials and impurities during the high-temperature melting process, and improve the acid and alkali resistance of the glass-ceramics. P 2 O 5 If the content is lower than 0.37 mol%, it will cause problems such as high high-temperature viscosity and the generation of raw materials and impurities during the high-temperature melting process. P 2 O 5 If it is higher than 0.55 mol%, it will affect the acid and alkali resistance.

[0041] SnO 2 The content is 0.05 mol% - 0.15 mol%, which can promote the removal of bubbles from the glass-ceramics at high temperatures and avoid premature crystallization during the calendering process. If it is less than 0.05 mol%, there are likely to be bubbles in the glass-ceramics. If it is greater than 0.15 mol%, premature crystallization is likely to occur during the calendering process.

[0042] B 2 O 3 Elements such as F will increase the thermal expansion coefficient of the glass-ceramics and reduce the acid and alkali resistance. As 2 O 3 、Sb 2 O 3 has physiological toxicity. As 2 O 3 +Sb 2 O 3 +B 2 O 3 +F < 0.1 mol% can reduce the thermal expansion coefficient of the glass-ceramics, improve the acid and alkali resistance, and reduce the physiological toxicity at the same time.

[0043] SiO 2 Can play a role in improving the acid and alkali resistance of glass-ceramics, but has a high melting point and is difficult to melt. Al 2 O 3 Can also play a role in improving the acid and alkali resistance, but will increase the viscosity of the glass-ceramics, easily leading to difficulties in high-temperature melting, and too fast hardening during the rolling process. SiO 2 and Al 2 O 3 The addition of increases the difficulty of melting and forming while improving the acid and alkali resistance. The addition of P 2 O 5 Can reduce the high-temperature viscosity, improve the solubility of high-melting-point substances such as alumina and zirconia in the glass, and avoid defects such as raw materials and impurities during the high-temperature melting process, but it is easy to cause a decrease in the acid and alkali resistance of the glass-ceramics. When the SiO 2 content is 69.5 mol% - 71.5 mol%, the Al 2 O 3 content is 13 mol% - 14.2 mol%, and the P 2 O 5 content is 0.37 mol% - 0.55 mol%, making 1.65 < (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5 ) < 2.2 can improve the acid and alkali erosion resistance of the glass-ceramics while keeping the viscosity of the glass-ceramics within a suitable range for high-temperature melting and forming. For the (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5 ) of the present invention, if it is greater than 2.2, it is easy to cause difficulties in high-temperature melting, bubbles cannot be removed, too fast hardening during the rolling process, and the problem of crystallization before rolling. If it is less than 1.65, it is easy to cause the problem of decreased acid and alkali resistance.

[0044] The chemical composition of the glass-ceramics of the present invention includes SiO 2 : 69.5 mol% - 71.5 mol%, Al 2 O 3 : 13 mol% - 14.2 mol%, Li 2 O: 7.4 mol% - 8.8 mol%, P 2 O 5 : 0.37 mol% - 0.55 mol%, SnO 2 : 0.05 mol% - 0.15 mol%, As2 O 3 +Sb 2 O 3 +B 2 O 3 +F < 0.1 mol%, 1.65 < (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5 ) < 2.2, based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 1.2% - 9.3%. Through the content of each oxide, the SiO 2 +Al 2 O 3 and P 2 O 5 content relationship, and the interaction between the content relationship of hydrothermal quartz solid solution and the content relationship of high quartz solid solution, can simultaneously improve the high-temperature melting and processing properties of the glass-ceramics, improve the acid and alkali erosion resistance of the glass-ceramics, reduce the thermal expansion of the glass-ceramics, and improve the thermal shock resistance of the glass-ceramics. Conduct an acid erosion test on the glass-ceramics, the erosion amount ≤ 15 mg / dm 2 , conduct an alkali erosion test on the glass-ceramics, the erosion amount ≤ 175 mg / dm 2 , the glass-ceramics are used in occasions such as kitchen stove tops and household appliance panels, and can meet the usage requirements of kitchen stove tops and household appliance panels.

[0045] The SiO 2 content of the present invention is, for example, 69.5 mol%, 70 mol%, 70.5 mol%, 71 mol% and 71.5 mol%, the Al 2 O 3 content is, for example, 13 mol%, 13.3 mol%, 13.6 mol%, 13.8 mol% and 14.2 mol%, the Li 2 O content is, for example, 7.4 mol%, 7.7 mol%, 8.1 mol%, 8.4 mol% and 8.8 mol%, the P 2 O 5 content is, for example, 0.37 mol%, 0.39 mol%, 0.43 mol%, 0.48 mol%, 0.51 mol% and 0.55 mol%, the SnO 2 content is, for example, 0.05 mol%, 0.07 mol%, 0.09 mol%, 0.11 mol%, 0.13 mol% and 0.15 mol%, (SiO 2 +Al 2 O 3 ) / (100×P2 O 5 ) For example, they are 1.65, 1.7, 1.8, 1.9, 2, 2.1 and 2.2, and the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is, for example, 1.2%, 2.5%, 3.5%, 4.5%, 5.5%, 6.5%, 7.5%, 8.5% and 9.3%.

[0046] The acid erosion resistance test method of the present invention refers to GB / T 15728-2021 or DIN 121166-2001, and the alkali erosion resistance test method refers to GB / T 6580-2021 or ISO 695-1991. The formula for the acid erosion amount is H = (mass difference / surface area) / 2, that is, for the acid erosion resistance test, half of the erosion amount at 6 h is taken as the erosion amount; the formula for the alkali erosion amount is ρ = mass difference / surface area, that is, for the alkali erosion resistance test, the erosion amount value at 3 h is taken as the erosion amount.

[0047] In some preferred embodiments, based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 2.5% - 8.2%, and further preferably, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 2.8% - 7.4%. Under this preferred scheme, it is more conducive to improving the acid and alkali resistance of the glass-ceramics.

[0048] Based on the total mass of the crystals contained in the glass-ceramics of the present invention, the total of the mass content of hydrothermal quartz solid solution and the mass content of high quartz solid solution is preferably greater than 95 wt%.

[0049] In some preferred embodiments, 1.75 < (SiO 2 +Al 2 O 3 ) / (100 × P 2 O 5 ) < 2.2, and further preferably, 1.9 < (SiO 2 +Al 2 O 3 ) / (100 × P 2 O 5 ) < 2.2. Under this preferred scheme, it is more conducive to maintaining the viscosity of the glass-ceramics within the range suitable for high-temperature melting and forming processing while improving the acid and alkali erosion resistance of the glass-ceramics.

[0050] In some preferred embodiments, its chemical composition in terms of mole percentage further includes: 1.5 < (CaO + 0.4 × MgO + 1.2 × ZnO) / [0.5 × (BaO + SrO) + 1 × Na 2 O + 0.2 × K 2 O] < 2.4.

[0051] The present invention discovers that during the controllable crystallization process of LAS system glass-ceramics, β-quartz solid solution can be formed, which has unique low expansion characteristics. Alkali metals and alkaline earth metals play a fluxing role during the glass melting process, reducing the difficulty of melting the glass-ceramics and improving the quality of the glass melt. However, during the high-temperature crystallization process, the effects of these two groups of elements are different. Although lithium oxide is an alkali metal element, it is the main component of the crystal phase of LAS glass-ceramics. In addition to this, other alkali metal and alkaline earth metal elements will cause an increase in the expansion coefficient of the glass-ceramics. Among them, sodium oxide and potassium oxide, as network modifiers, can break the Si-O bonds and cause some bridging oxygen bonds to break, weakening the acid and alkali resistance of the glass. At the same time, during the crystallization process, they tend to accumulate in the residual glass phase. As their content increases, it has a greater impact on the increase in the expansion coefficient and the weakening of the acid and alkali resistance of the glass-ceramics. Barium oxide also accumulates in the residual glass phase. As its content increases, it will also lead to deterioration of the thermal shock resistance and acid and alkali resistance. Uniquely, elements such as Ca, Mg, and Zn can be dissolved in the β-quartz solid solution during the high-temperature crystallization process, increasing the crystallinity. Their influence on the expansion coefficient is less than that of alkali metal elements such as Na and K, and it is beneficial to maintain better acid and alkali resistance (the doping of Ca, Mg, Zn, etc. into the crystal will bring some changes to the unit cell parameters, but the impact is not significant). Among them, the expansion coefficient of the β-quartz solid solution formed by Zn is lower than that formed by Mg. In SiO 2 content is 69.5 mol% to 71.5 mol%, Al 2 O 3 content is 13 mol% to 14.2 mol%, Li 2 O content is 7.4 mol% to 8.8 mol%, P 2 O 5 content is 0.37 mol% to 0.55 mol%, SnO 2 content is 0.05 mol% to 0.15 mol%, As 2 O 3 +Sb 2 O 3 +B 2 O 3 +F content is < 0.1 mol%, 1.65 < (SiO 2 +Al 2 O 3 ) / (100×P 2 O 5 ) < 2.2, based on the total mass of the crystals contained in the glass-ceramics, on the basis that the ratio of the mass content of the hydrothermal quartz solid solution to the mass content of the high quartz solid solution is 1.2% to 9.3%, (CaO + 0.4×MgO + 1.2×ZnO) / [0.5×(BaO + SrO) + 1×Na 2O + 0.2×K 2 O is not higher than 2.4, which is more conducive to improving the high-temperature fusibility, reducing the melting and forming processing difficulties of the glass-ceramics. (CaO + 0.4×MgO + 1.2×ZnO) / [0.5×(BaO + SrO) + 1×Na 2 O + 0.2×K 2 O is not lower than 1.5, which is more conducive to reducing the thermal expansion coefficient of the glass-ceramics, improving the thermal shock resistance and acid and alkali resistance.

[0052] (CaO + 0.4×MgO + 1.2×ZnO) / [0.5×(BaO + SrO) + 1×Na 2 O + 0.2×K 2 O] is, for example, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3 and 2.4.

[0053] Preferably, 1.6 < (CaO + 0.4×MgO + 1.2×ZnO) / [0.5×(BaO + SrO) + 1×Na 2 O + 0.2×K 2 O] < 2.4. Further preferably, 2 < (CaO + 0.4×MgO + 1.2×ZnO) / [0.5×(BaO + SrO) + 1×Na 2 O + 0.2×K 2 O] < 2.4. Under this preferred scheme, it is more conducive to reducing the melting difficulty of the glass-ceramics while reducing the thermal expansion coefficient of the glass-ceramics, improving the thermal shock resistance and acid and alkali resistance.

[0054] In some preferred embodiments, its chemical composition in mole percentage further includes: CaO: 0.05 mol% to 0.50 mol%, MgO: 0.90 mol% to 1.40 mol%, ZnO: 0.95 mol% to 1.45 mol%, SrO + BaO: 0.55 mol% to 0.80 mol%, K 2 O + Na 2 O: 0.6 mol% to 1.0 mol%.

[0055] The content of CaO is not higher than 0.50 mol%, which is more conducive to preventing accidental crystallization during the calendering process. The content of MgO is not lower than 0.90 mol%, which is more conducive to improving the high-temperature fluxing effect, inhibiting crystallization during the forming process, and reducing the heat treatment temperature of the crystallization process. MgO can be dissolved in high quartz or hydrothermal quartz to increase the crystallinity of the glass-ceramics, but significantly increases the thermal expansion coefficient. The content of MgO is not higher than 1.4 mol%, which is more conducive to reducing the thermal expansion coefficient of the glass-ceramics. The content of ZnO is not lower than 0.95 mol%, which is more conducive to reducing the viscosity of the glass-ceramics, inhibiting crystallization during the forming process, reducing the melting temperature and crystallization temperature, and increasing the crystallinity. ZnO can be dissolved in high quartz or hydrothermal quartz to increase the crystallinity but will increase the thermal expansion coefficient of the glass-ceramics. The content of ZnO is not higher than 1.45 mol%, which is more conducive to reducing the thermal expansion coefficient of the glass-ceramics. Oxides such as BaO, Na 2 O, K 2 O, etc. play a fluxing role during the high-temperature melting process of the glass-ceramics, which can improve the melting quality. However, during the high-temperature crystallization process, these three oxides are enriched in the residual glass phase, increasing the thermal expansion coefficient while reducing the acid and alkali resistance of the glass-ceramics. The content of SrO + BaO is not lower than 0.55 mol%, which is more conducive to improving the fusibility of the high-temperature glass, increasing the refractive index of the LAS glass-ceramics, and improving the appearance texture. It is not higher than 0.80 mol%, which is more conducive to reducing the thermal expansion coefficient of the glass-ceramics, improving the thermal shock resistance and acid and alkali resistance. K 2 O + Na 2 O content is not lower than 0.6 mol%, which is more conducive to reducing the viscosity of the glass-ceramics, reducing the difficulty of high-temperature melting and calendering, reducing the crystallization temperature, and improving the preparation ability of the glass-ceramics. It is not higher than 1.0 mol%, which is more conducive to reducing the thermal expansion coefficient of the glass-ceramics, improving the thermal shock resistance and acid and alkali resistance. It can be understood that for different batches of ore raw materials, the calcium oxide composition will fluctuate significantly. When necessary, calcium carbonate minerals need to be added additionally to maintain the stability of the composition during the production process. Sodium oxide and potassium oxide are generally present in the mineral raw materials. When necessary, they can also be added in the form of potassium salts, sodium salts, etc.

[0056] The CaO content of the present invention is, for example, 0.05 mol%, 0.1 mol%, 0.2 mol%, 0.3 mol%, 0.4 mol% and 0.5 mol%. The MgO content is, for example, 0.9 mol%, 1 mol%, 1.1 mol%, 1.2 mol%, 1.3 mol% and 1.4 mol%. The ZnO content is, for example, 0.95 mol%, 1.05 mol%, 1.15 mol%, 1.25 mol%, 1.35 mol% and 1.45 mol%. The SrO + BaO content is, for example, 0.55 mol%, 0.6 mol%, 0.7 mol% and 0.8 mol%. K 2 O + Na 2The O content is, for example, 0.6 mol%, 0.7 mol%, 0.8 mol%, 0.9 mol% and 1 mol%.

[0057] In some preferred embodiments, its chemical composition further includes, in mole percentage: 0.71 < (TiO 2 + ZrO 2 ) / (R 2 O + RO) < 0.89, where R 2 O represents the oxide of monovalent alkali metal elements other than Li 2 O, and RO represents the oxide of divalent metal elements, including Zn in Group IIA and Group IIB.

[0058] The crystal phase of the glass-ceramics has better acid and alkali erosion resistance than the glass phase. Increasing the total content of the nucleating agents TiO 2 and ZrO 2 is beneficial to promoting crystallization. However, too high a content of nucleating agents will lead to a decrease in the content of flux or the content of the glass framework; a decrease in the flux content will lead to difficult melting of the glass, an increase in bubbles, and uneven melting, resulting in a decline in product quality or a sharp increase in production costs; a decrease in the glass framework composition will lead to a decline in acid and alkali resistance. Too low a total content of TiO 2 and ZrO 2 will result in too high a crystallization activation energy of the glass-ceramics, a decrease in crystallization efficiency, a decrease in crystallinity, and will also weaken the acid and alkali resistance of the glass-ceramics. Lithium oxide is the main component of the LAS-based glass-ceramics. Here, R 2 O does not contain lithium oxide, generally sodium oxide, potassium oxide, and may also include cesium oxide and rubidium oxide. Here, RO is generally calcium oxide, magnesium oxide, zinc oxide, barium oxide, etc., and may also include strontium oxide. By mutually restricting the total amount of nucleating agents and the total amount of flux, the content of (TiO 2 + ZrO 2 ) / (R 2 O + RO) is not less than 0.71, which is more conducive to ensuring that the crystallization temperatures of high quartz and hydrothermal quartz are within a reasonable working temperature, and the crystallization efficiency is suitable for industrial production, improving the crystallinity, and improving the acid and alkali resistance of the glass-ceramics. The content of (TiO 2 + ZrO 2 ) / (R 2 O + RO) is not higher than 0.89, which is more conducive to reducing the melting difficulty, improving the quality of the glass-ceramics or reducing the production cost, and improving the acid and alkali resistance of the glass-ceramics. (TiO 2 + ZrO 2 ) / (R 2 O + RO) is, for example, 0.71, 0.72, 0.74, 0.76, 0.78, 0.8, 0.83, 0.86 and 0.89.

[0059] Preferably, 0.73 < (TiO 2 + ZrO 2 ) / (R 2 O + RO) < 0.87, and more preferably, 0.75 < (TiO 2 + ZrO 2 ) / (R 2 O + RO) < 0.85. Under this preferred scheme, it is more conducive to improving the crystallization efficiency, increasing the crystallinity, enhancing the acid and alkali resistance of the glass-ceramics, reducing the melting difficulty, improving the quality of the glass-ceramics or reducing the production cost.

[0060] In some preferred embodiments, its chemical composition in mole percentage further includes: TiO 2 : 2.3 mol% - 2.65 mol%, ZrO 2 : 0.65 mol% - 0.95 mol%. TiO 2 and ZrO 2 are the main nucleating agents of LAS glass-ceramics. Compared with using titanium oxide or zirconium oxide alone, the synergistic effect of using both is significant, which is more conducive to greatly reducing the crystallization temperature of LAS. The content of TiO 2 is not less than 2.3 mol% and not higher than 2.65 mol%, which is more conducive to the synergistic efficiency of the nucleating agent, reducing the crystallization temperature, improving the crystallization efficiency, increasing the crystallinity, and enhancing the acid and alkali resistance of the glass-ceramics. The content of ZrO 2 is not less than 0.65 mol%, which is more conducive to the synergistic efficiency of the nucleating agent, increasing the crystallinity, and enhancing the acid and alkali resistance of the glass-ceramics. The content of ZrO 2 is not higher than 0.95 mol%, which is more conducive to ensuring the devitrification resistance during the high-temperature melting process. The TiO content of the present invention is, for example, 2.3 mol%, 2.35 mol%, 2.45 mol%, 2.55 mol%, and 2.65 mol%, and the ZrO 2 content is, for example, 0.65 mol%, 0.7 mol%, 0.8 mol%, 0.9 mol%, and 0.95 mol%.

[0061] Thirdly, the present invention provides a method for preparing acid and alkali resistant glass-ceramics, including: proportioning according to the components contained in the glass-ceramics described in the first aspect, mixing and melting, then forming, and then carrying out crystal growth. The glass-ceramics prepared by the preparation method of the present invention have significantly improved acid and alkali resistance, can meet the usage requirements of kitchen stove tops and household appliance panels, and protect the appearance of the glass-ceramic panel during use.

[0062] Fourthly, the present invention provides a kitchen stove or kitchen appliance, which includes the glass-ceramics described in the first aspect and / or the glass-ceramics prepared by the preparation method described in the second aspect.

[0063] Embodiments of the present invention will be described in detail below. They are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention.

[0064] Example 1

[0065] The composition of the glass-ceramics is shown in Table 1. The preparation method of the glass-ceramics includes: weighing materials according to the components contained in Table 1, mixing and melting, rolling and solidifying by calendering to form flat glass, and performing crystal growth on the glass obtained by rolling and solidifying. During the crystal growth process, first heat up from room temperature to 760 °C, keep the temperature for 20 min for nucleation, then continue to heat up to 920 °C, and keep the temperature for 40 min for crystallization to obtain the glass-ceramics.

[0066] The crystal phase of the glass-ceramics in Example 1 was tested. The test equipment was Bruker d8 advance. The test method and calculation process were as follows: comparing the measured spectrum with the pdf standard card, and after matching the intensities of the two, calculating the content ratio with eva software. See Figure 1 for the crystal phase test chart of the glass-ceramics in Example 1. Based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is shown in Table 1. The glass-ceramics in Example 1 were tested for acid and alkali resistance. The test results are shown in Table 1. The test conditions for the acid resistance test were that the erosion solution was a HCl solution with a concentration of 6 mol / L, and the erosion was carried out under boiling conditions for 6 h. The test conditions for the alkali resistance test were that the erosion solution was a solution prepared by mixing an equal volume of a Na 2 CO 3 solution with a concentration of 0.5 mol / L and a NaOH solution with a concentration of 1 mol / L, and the erosion was carried out under boiling conditions for 3 h. The acid resistance test method of the present invention refers to GB / T15728-2021 or DIN 121166-2001, and the alkali resistance test method refers to GB / T 6580-2021 or ISO 695-1991. The formula for the acid resistance erosion amount is H = (mass difference / surface area) / 2, that is, for the acid resistance test, half of the 6 h erosion amount value is taken as the erosion amount; the formula for the alkali resistance erosion amount is ρ = mass difference / surface area, that is, for the alkali resistance test, the 3 h erosion amount value is taken as the erosion amount. The glass-ceramics in Example 1 were tested for the linear thermal expansion coefficient from 40 °C to 700 °C. The test results are shown in Table 1.

[0067] Examples 2-17

[0068] They were respectively carried out with reference to the method of Example 1, except that the composition and / or crystallization process parameters of the glass-ceramics were different, as shown in Table 1 specifically. And corresponding tests were carried out. The test results are shown in Table 1.

[0069] Comparative Examples 1-4

[0070] It was carried out with reference to the method of Example 1 respectively, except that the composition of the glass-ceramics and / or the crystallization process parameters were different, as specifically shown in Table 2. And corresponding tests were carried out, and the test results are shown in Table 2.

[0071] The test curve graphs of the linear thermal expansion coefficients of the glass-ceramics of Example 1, Example 13, Comparative Example 1 and Comparative Example 2 from 40 °C to 700 °C are shown in Figure 2 .

[0072] Table 1

[0073]

[0074]

[0075]

[0076]

[0077]

[0078] Table 2

[0079]

[0080] Comparing Examples 1 to 17 and Comparative Examples 1 to 2 and 4, based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of hydrothermal quartz solid solution to the mass content of high quartz solid solution is 1.2% to 9.3%, which can improve the acid and alkali resistance of the glass-ceramics; comparing Examples 1 to 17 and Comparative Example 3, 1.65 < (SiO 2 + Al 2 O 3 ) / (100 × P 2 O 5 ) < 2.2, which can improve the acid and alkali resistance of the glass-ceramics.

[0081] Comparing Examples 1 to 10, 1.75 < (SiO 2 + Al 2 O 3 ) / (100 × P 2 O 5 ) < 2.2 is more conducive to improving the acid and alkali resistance of the glass-ceramics, 1.9 < (SiO 2 + Al 2 O 3 ) / (100 × P 2 O 5 ) < 2.2 is further more conducive to improving the acid and alkali resistance of the glass-ceramics. Comparing Examples 1 to 7 and Examples 11 to 12, 2 < CaO + 0.4 × MgO + 1.2 × ZnO) / [0.5 × (BaO + SrO) + 1 × Na2 O + 0.2×K 2 O]<2.4, which is more conducive to reducing the thermal expansion coefficient of the glass-ceramics, improving the thermal shock resistance and acid and alkali resistance. Comparing Examples 1-7 and Examples 13-17, based on the total mass of the crystals contained in the glass-ceramics, the ratio of the mass content of the hydrothermal quartz solid solution to the mass content of the high quartz solid solution is 2.5% - 8.2%, which is more conducive to improving the acid and alkali resistance of the glass-ceramics.

Claims

1. An acid- and alkali-resistant glass-ceramic, characterized in that: Its chemical composition includes SiO2: 69.5mol% to 71.5mol%, Al2O3: 13mol% to 14.2mol%, Li2O: 7.4mol% to 8.8mol%, P2O5: 0.37mol% to 0.55mol%, SnO2: 0.05mol% to 0.15mol%, As2O3+Sb2O3+B2O3+F<0.1mol%, 1.65<(SiO2+Al2O3) / (100×P2O5)<2.2; Based on the total mass of crystals contained in the glass-ceramics, the ratio of the mass content of the keatnetite solid solution to the mass content of the high quartz solid solution is 1.2% to 9.3%; The microcrystalline glass is subjected to an acid corrosion resistance test, and the corrosion amount is ≤15mg / dm 2 The test conditions of the acid corrosion test include: the corrosion liquid is a 6 mol / L HCl solution, and the corrosion is carried out under boiling conditions for 6 hours; the alkali corrosion test of the microcrystalline glass is carried out, and the corrosion amount is ≤175mg / dm 2 The detection conditions of the alkali corrosion resistance test include: the corrosion liquid is a solution of equal volumes of a 0.5 mol / L Na2CO3 solution and a 1 mol / L NaOH solution, and the corrosion is carried out for 3 hours under boiling conditions.

2. The glass-ceramic according to claim 1, characterized in that: Taking the total mass of crystals contained in the microcrystalline glass as a reference, the ratio of the mass content of the hydrothermal quartz solid solution to the mass content of the high quartz solid solution is 2.5% to 8.2%.

3. The glass-ceramic according to claim 2, characterized in that: The ratio of the mass content of the hydrothermal quartz solid solution to the mass content of the high quartz solid solution is 2.8% to 7.4%.

4. The glass-ceramic according to claim 1, characterized in that: 1.75<(SiO2+Al2O3) / (100×P2O5)<2.

2.

5. The glass-ceramic according to claim 4, characterized in that: 1.9<(SiO2+Al2O3) / (100×P2O5)<2.

2.

6. The glass-ceramic according to claim 1, characterized in that: Its chemical composition in terms of molar percentage also includes: 1.5<(CaO+0.4×MgO+1.2×ZnO) / [0.5×(BaO+SrO)+1×Na2O+0.2×K2O]<2.

4.

7. The glass-ceramics according to claim 6, characterized in that: 1.6<(CaO+0.4×MgO+1.2×ZnO) / [0.5×(BaO+SrO)+1×Na2O+0.2×K2O]<2.

4.

8. The glass-ceramics according to claim 7, characterized in that: 2<CaO+0.4×MgO+1.2×ZnO) / [0.5×(BaO+SrO)+1×Na2O+0.2×K2O]<2.

4.

9. The glass-ceramic according to claim 1, characterized in that: Its chemical composition, in terms of molar percentage, also includes: CaO: 0.05mol% to 0.50mol%, MgO: 0.90mol% to 1.40mol%, ZnO: 0.95mol% to 1.45mol%, SrO+BaO: 0.55mol% to 0.80mol%, K2O+Na2O: 0.6mol% to 1.0mol%.

10. The glass-ceramic according to claim 1, characterized in that: Its chemical composition in terms of molar percentage also includes: 0.71<(TiO2+ZrO2) / (R2O+RO)<0.89, R2O represents a monovalent alkali metal element oxide except Li2O, and RO represents a divalent metal element oxide.

11. The glass-ceramic according to claim 10, characterized in that: 0.73<(TiO2+ZrO2) / (R2O+RO)<0.

87.

12. The glass-ceramic according to claim 11, characterized in that: 0.75<(TiO2+ZrO2) / (R2O+RO)<0.

85.

13. The glass-ceramic according to claim 1, characterized in that: Its chemical composition in terms of molar percentage also includes: TiO2: 2.3mol% to 2.65mol%, ZrO2: 0.65mol% to 0.95mol%.

14. A method for preparing acid- and alkali-resistant microcrystalline glass, characterized in that: include: The components of the microcrystalline glass as described in any one of claims 1 to 13 are mixed and melted, then formed, and then crystal growth is carried out.

15. A kitchen stove or kitchen appliance, characterized in that: It includes the microcrystalline glass according to any one of claims 1 to 13 and / or the microcrystalline glass prepared by the preparation method according to claim 14.

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