Triclinic nepheline glass ceramic, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of glass ceramics, and disclosed therein are a triclinic nepheline glass ceramic, and a preparation method therefor and the use thereof. The glass ceramic comprises the following components in molar percentages: 43-58 mol% of SiO2, 15-27 mol% of Al2O3, 20-28 mol% of Na2O, 0-10 mol% of Li2O, 0-10 mol% of K2O, 1-5 mol% of P2O5, and 0.3-3 mol% of ZrO2. According to the glass ceramic provided by the present invention, the crystal phase composition can only include a main crystal phase of a triclinic nepheline phase, or can further include a secondary crystal phase of a nepheline phase and a phosphate phase, and the phosphate phase in the crystal phase is reduced or removed, thus improving the chemical stability of the glass ceramic.

Description

A triclinic nepheline glass-ceramic, its preparation method and application Technical Field

[0001] This invention relates to the field of glass and ceramics technology, and in particular to a triclinic nepheline glass-ceramic, its preparation method, and its applications. Background Technology

[0002] Glass ceramics are a type of composite material that combines crystalline phases with glass through high-temperature melting, molding, and heat treatment. Compared with glass, glass ceramics have a more stable nanocrystalline structure, resulting in higher mechanical strength and a lower coefficient of thermal expansion. Therefore, they are widely used in electronic devices, automobiles, construction, and other fields.

[0003] Nepheline glass-ceramics possess good mechanical strength and can be strengthened using known ion exchange methods. Existing nepheline glass-ceramics consist of a primary nepheline phase and a secondary phosphate phase. Nepheline crystals improve the mechanical strength of the glass-ceramic, while phosphate crystals form at lower temperatures than nepheline crystals and nucleate nepheline crystals at a fine scale (e.g., approximately tens of nanometers). However, the phosphate phase has poor chemical stability, and its presence reduces the corrosion resistance of nepheline glass-ceramics. This hinders subsequent chemical strengthening and cleaning processes, leading to decreased yield and production efficiency. Summary of the Invention

[0004] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a triclinic nepheline glass-ceramic; a second objective is to provide a method for preparing such a glass-ceramic; a third objective is to provide a chemically strengthened glass-ceramic; and a fourth objective is to provide applications of the glass-ceramic or chemically strengthened glass-ceramic.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of the present invention provides a triclinic nepheline glass-ceramic, comprising the following components by molar percentage: 43-58 mol% SiO2, 15-27 mol% Al2O3, 20-28 mol% Na2O, 0-10 mol% Li2O, 0-10 mol% K2O, 1-5 mol% P2O5, and 0.3-3 mol% ZrO2.

[0007] According to the above scheme, the molar percentage ratio of P2O5 to ZrO2 is 1 to 4, which can be one of 4 / 1, 3 / 1, 2 / 1, or 1, that is, within the range of 4 / 1 to 1 / 1. More preferably, the molar percentage ratio of P2O5 to ZrO2 is 1.1 to 4.

[0008] Preferably, in the glass-ceramic, Al2O3 is 15-25 mol%, Na2O is 21-28 mol%, P2O5 is 1-4 mol%, and ZrO2 is 1-2 mol%.

[0009] Preferably, in the glass-ceramic, Al2O3 is 15-23 mol%, Na2O is 21-28 mol%, P2O5 is 1-4 mol%, and ZrO2 is 0.3-3 mol%.

[0010] Preferably, in the glass-ceramic, SiO2 is 48-58 mol%, Al2O3 is 15-20 mol%, P2O5 is 1.5-3.5 mol%, and ZrO2 is 0.3-2 mol%.

[0011] Preferably, in the glass-ceramic, SiO2 is 43-53 mol%, Al2O3 is 18-25 mol%, Na2O is 18-24 mol%, Li2O is 2-6 mol%, K2O is 0-2 mol%, and P2O5 is 2.5-5 mol%.

[0012] According to the above scheme, the glass-ceramic further comprises the following components by molar percentage: 0~10 mol% ZnO, 0~10 mol% CaO, 0~10 mol% MgO, 0~10 mol% SrO, 0~10 mol% B2O3, and 0~10 mol% BaO. More preferably, the molar percentages of the above components are: 0~4 mol% ZnO, 0~3 mol% CaO, 0~3 mol% MgO, 0~2 mol% SrO, and 0~3 mol% B2O3.

[0013] Preferably, in the glass-ceramic, the SiO2 content, by molar percentage, can be any one of 43-56 mol%, 43-54 mol%, 43-52 mol%, 45-58 mol%, 47-58 mol%, 49-58 mol%, or 49-56 mol%. SiO2, as the main component of the glass-ceramic, constitutes the glass matrix. Furthermore, SiO2 can be used as a viscosity enhancer to improve glass formability and impart mechanical durability to the glass.

[0014] Preferably, in the glass-ceramic, the content of Al2O3, by molar percentage, can be any one of 15~21 mol%, 17~25 mol%, 19~25 mol%, or 19~23 mol%.

[0015] Preferably, in the glass ceramic, the Na2O content, by molar percentage, can be any one of 18-26 mol%, 18-24 mol%, 20-28 mol%, 22-28 mol%, or 22-26 mol%.

[0016] Preferably, in the glass ceramic, the K2O content, by molar percentage, can be any one of 0~8mol%, 0~6mol%, 2~10mol%, 4~10mol%, or 4~8mol%.

[0017] Preferably, in the glass ceramic, the content of Li2O, by molar percentage, can be any one of 0~8mol%, 0~6mol%, 2~10mol%, 4~10mol%, or 4~8mol%.

[0018] The glass-ceramic of the present invention can also contain chemical clarifying agents, such as SnO2, As2O3, Sb2O3, halides, CeO2, Fe2O3, MnO2, etc. When SnO2, As2O3, Sb2O3, or halides are used as chemical clarifying agents, their mass percentage content in the glass-ceramic is 0-3%; when CeO2, Fe2O3, or MnO2 are used as chemical clarifying agents, their mass percentage content in the glass-ceramic is 0-0.5%.

[0019] According to the above scheme, the triclinic nepheline glass-ceramic of the present invention is composed of a main crystalline phase, a secondary crystalline phase, and a residual glass phase; wherein, the mass percentage of the main crystalline phase is 30-90%, the mass percentage of the secondary crystalline phase is 0-49%, and the balance is the residual glass phase; the main crystalline phase is one of triclinic nepheline phase, triclinic nepheline and its solid solution crystalline phase; the secondary crystalline phase is at least one of nepheline phase and phosphate phase, the mass of the nepheline phase accounts for 0-39% of the mass of the glass-ceramic; the mass of the phosphate phase accounts for 0-10% of the mass of the glass-ceramic.

[0020] Preferably, the mass percentage of the main crystalline phase in the glass-ceramic is 60-85%, and the mass percentage of the secondary crystalline phase is 0-10%. More preferably, the secondary crystalline phase is nepheline.

[0021] More preferably, the nepheline phase accounts for 0-10% of the mass of the glass-ceramic, and the phosphate phase accounts for 0-5% of the mass of the glass-ceramic.

[0022] Specifically, the triclinic nepheline includes at least one of low-temperature triclinic nepheline and high-temperature triclinic nepheline; the low-temperature triclinic nepheline (NaAlSiO4, low-carnegieite) has an orthorhombic crystal system and a space group of Pmaa; the high-temperature triclinic nepheline (NaAlSiO4, high-carnegieite) has a cubic crystal system.

[0023] Specifically, the solid solution includes at least one of NaAlSiO4-SiO2 solid solution, (Na,K)AlSiO4 solid solution, (Na,K)AlSiO4-SiO2 solid solution, R(Al,Si)O4 (where R = Na, K, Mg, Ca, Ba or a hole), (K,Na)SiO4, CaO, and SiO2; the R(Al,Si)O4 (where R = Na, K, Mg, Ca, Ba or a hole) is an orthorhombic (Pmaa) network silicate, the structure of which is a "filled" derivative of silica in the form of β-cristobalite; in the (Na,K)AlSiO4-SiO2 solid solution, Na is dominant relative to K.

[0024] Specifically, the nepheline phase is a hexagonal (P63) network silicate with a structure that is a “filled” derivative of silica in the form of β-tridymite.

[0025] Specifically, the phosphate phase includes a crystalline phosphate phase and an amorphous phosphate phase; the amorphous or crystalline phosphate phase can form at a lower temperature than nepheline crystals; the amorphous or crystalline phosphate phase (approximately tens of nanometers) promotes the precipitation of triclinic nepheline and nepheline. Preferably, the size of the crystalline phosphate phase is ≤30 nm; the amorphous phosphate phase is uniformly or interconnectedly distributed within the glass-ceramic.

[0026] According to the above scheme, the main crystalline phase and the secondary crystalline phase in the glass ceramic both exist in crystalline form, and the main cross-sectional size of the crystal does not exceed 94 nm; more preferably, the main cross-sectional size of the crystal is 30~89 nm.

[0027] According to the above scheme, the microstructure of the glass ceramic is a regionally segmented grid, with a grid diameter of 30~300nm; this regionally segmented grid microstructure can restrict crystal growth and has a significant self-limiting crystallization effect.

[0028] According to the above scheme, when the thickness of the glass ceramic is 0.7 mm, the average transmittance at a wavelength of 380~780 nm is 65%~93%; preferably, when the thickness of the glass ceramic is 0.7 mm, the average transmittance at a wavelength of 380~780 nm is 68%~91%.

[0029] Preferably, the haze of the glass-ceramic is 0.1 to 0.3; more preferably, the haze of the glass-ceramic is 0.1 to 0.2; the haze is the percentage of transmitted light scattered outside an angular cone of ±4.0°, as determined by ASTM method D1003.

[0030] Preferably, the crystallinity of the glass-ceramic is 30-90 wt%; more preferably, the crystallinity of the glass-ceramic is 40-90 wt%; even more preferably, the crystallinity of the glass-ceramic is 50-90 wt%; even more preferably, the crystallinity of the glass-ceramic is 60-90 wt%; and most preferably, the crystallinity of the glass-ceramic is 65-85 wt%.

[0031] Preferably, the glass-ceramic is colorless and transparent.

[0032] Preferably, the refractive index of the glass-ceramic is 1.4 to 1.6.

[0033] Preferably, the Vickers hardness of the glass-ceramic is 5~8.5 GPa.

[0034] A second aspect of the present invention provides a method for preparing the glass-ceramic described in the first aspect of the present invention, comprising the following steps:

[0035] S1. The components are melted and mixed at 1400~1600℃ to obtain the precursor glass;

[0036] S2. The precursor glass is heat-treated to obtain the glass ceramic.

[0037] Preferably, in step S1, the mixing and melting time is 3-5 hours.

[0038] Preferably, in step S1, after mixing and melting, the process further includes casting and annealing; the annealing temperature is 550~700℃ and the time is 3~5h.

[0039] Preferably, in step S1, the precursor glass can be a glass sheet or other arbitrary shape. The glass sheet can be formed by processes such as roll pressing, float glass, spin coating, and pressing, and its thickness is less than 5 mm.

[0040] Preferably, in step S2, the heat treatment method is selected from either one-step ceramization or two-step ceramization.

[0041] Preferably, the one-step ceramization method is as follows: the precursor glass is heated from room temperature to 620-800°C at a heating rate of 1-10°C / min, and held at that temperature for 0.5-8 hours to obtain glass ceramic.

[0042] Preferably, the two-step ceramization method is selected from any one of the following:

[0043] (1) The precursor glass is heated from room temperature to 600-650°C at a heating rate of 1-10°C / min, held for 0.5-2 hours, and then heated to 650-750°C at a heating rate of 1-10°C / min, held for 1-8 hours to obtain glass ceramic.

[0044] (2) The precursor glass is heated from room temperature to 700-800°C at a heating rate of 1-10°C / min, held for 1-2 hours, and then heated to 800-850°C at a heating rate of 1-10°C / min, held for 2-4 hours to obtain glass ceramic.

[0045] Preferably, after the heat treatment is completed, a step of cooling to room temperature is also included.

[0046] A third aspect of the present invention provides a chemically strengthened glass-ceramic, wherein the glass-ceramic is subjected to single or multiple ion exchanges in a mixed salt bath containing NaNO3 and / or KNO3 to obtain the chemically strengthened glass-ceramic. The preparation method of this chemically strengthened glass-ceramic is a one-step strengthening method, using KNO3... + Exchange Na in glass ceramics + This creates a compressive stress layer, increasing the strength of the glass.

[0047] Preferably, the chemically strengthened glass-ceramic can form a surface compressive stress in the range of 200~3000MPa, and the depth of the surface compressive stress ranges from 10~160μm.

[0048] Preferably, the Vickers hardness of the chemically strengthened glass ceramic is 6.5~9 GPa.

[0049] Preferably, the mass ratio of NaNO3 to KNO3 is 1:(0.25~4).

[0050] Preferably, the temperature of the ion exchange is 400~600℃.

[0051] Preferably, the ion exchange time is 1-12 hours; more preferably, the ion exchange time is 2-10 hours; even more preferably, the ion exchange time is 2-8 hours; and even more preferably, the ion exchange time is 4-8 hours.

[0052] The fourth aspect of the present invention provides the application of the glass ceramics described in the first aspect of the present invention, or the chemically strengthened glass ceramics described in the third aspect of the present invention, in electronic devices, transportation vehicles, buildings, and explosion-proof fields.

[0053] Compared with the prior art, the beneficial effects of the present invention are:

[0054] 1) The glass ceramic provided by the present invention may contain only the main crystalline phase triclinium nepheline phase, or may also contain secondary crystalline phases nepheline phase and phosphate phase. The reduction or removal of the phosphate phase in the crystalline phase improves the chemical stability of the glass ceramic, enabling the glass ceramic to be chemically strengthened, which is beneficial to ensuring the yield and production efficiency in the production process.

[0055] 2) The glass-ceramic preparation method provided by the present invention has simple steps and short time. The temperature-time distribution of the heat treatment step and the composition of the precursor glass can control the ratio of secondary crystalline phase and residual glass phase, forming a variety of crystalline phase compositions and grain sizes.

[0056] 3) The chemically strengthened glass ceramics provided by this invention have good physical properties such as hardness.

[0057] 4) The glass ceramics and chemically strengthened glass ceramics provided by this invention have excellent performance and can meet the application requirements in electronic devices, transportation vehicles, construction, and explosion-proof fields. Attached Figure Description

[0058] Figure 1 is a picture of the glass-ceramic sample in Example 1;

[0059] Figure 2 shows the XRD curve of the glass-ceramic in Example 3;

[0060] Figure 3 shows the transmittance curve of the glass-ceramic in Example 1;

[0061] Figure 4 shows the transmittance curve of the glass-ceramic in Example 8;

[0062] Figure 5 is a SEM image of the glass-ceramic in Example 13. Embodiments of the present invention

[0063] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the present invention is not limited to the following embodiments.

[0064] Unless otherwise specified, the raw materials, reagents, or apparatus used in the examples and comparative examples are available from conventional commercial sources or can be obtained by existing methods. Unless otherwise specified, the test or experimental methods are conventional methods in the art.

[0065] Example 1

[0066] This embodiment provides a glass-ceramic with the composition shown in Table 1, wherein the molar percentage ratio of P2O5 to ZrO2 is 1.6.

[0067] Table 1 Glass-ceramic composition of Example 1

[0068] Component content (mol%) SiO₂ 49.2 ZnO 0 Al₂O₃ 15.3 CaO 0 B₂O₃ 3.3 MgO 0 Na₂O₂ 8 P₂O₅ 2.4 Li₂O 0 ZrO₂ 1.5 K₂O 0 SrO 0.3

[0069] Glass ceramics are prepared by the following steps:

[0070] S1. After melting and refining each raw material at 1580℃ for 4 hours, cast it into a rectangular slab. The slab is then annealed at 580℃ for 4 hours to obtain the precursor glass.

[0071] S2. The precursor glass is heated from room temperature to 660°C at a heating rate of 5°C / min, held at that temperature for 8 hours, and then cooled to room temperature to obtain glass ceramic.

[0072] Figure 1 is a picture of the glass-ceramic sample in Example 1. It can be seen that the obtained glass-ceramic is colorless and transparent.

[0073] Example 2

[0074] This embodiment provides a glass-ceramic with the composition shown in Table 2, wherein the molar percentage ratio of P2O5 to ZrO2 is 1.65.

[0075] Table 2 Glass-ceramic composition of Example 2

[0076] Component content (mol%) Component content (mol%) SiO2 5 2 ZnO 3.1 Al2O3 1.5 CaO 2.8 B2O3 0 MgO 0 Na2O2 1.8 P2O5 3.3 Li2O 0 ZrO2 2 K2O 0 SrO 0

[0077] Glass ceramics are prepared by the following steps:

[0078] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0079] S2. The precursor glass is heated from room temperature to 600°C at a heating rate of 5°C / min, held at that temperature for 2 hours, then heated to 650°C at a heating rate of 5°C / min, held at that temperature for 1 hour, and cooled to room temperature to obtain glass ceramic.

[0080] Example 3

[0081] This embodiment provides a glass-ceramic with the composition shown in Table 3, wherein the molar percentage ratio of P2O5 to ZrO2 is 3.375.

[0082] Table 3 Glass-ceramic composition of Example 3

[0083] Component content (mol%) SiO₂ 5.2%, ZnO 0%, Al₂O₃ 1.7%, CaO 0%, B₂O₃ 0%, MgO 0%, Na₂O₂ 0%, P₂O₅ 2.7%, Li₂O 5.5%, ZrO₂ 0.8%, K₂O 1.7%, SrO 0.3%

[0084] Glass ceramics are prepared by the following steps:

[0085] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0086] S2. The precursor glass is heated from room temperature to 700°C at a heating rate of 5°C / min, held at that temperature for 1 hour, and then cooled to room temperature to obtain glass ceramic.

[0087] Example 4

[0088] This embodiment provides a glass-ceramic with the composition shown in Table 4, wherein the molar percentage ratio of P2O5 to ZrO2 is approximately 3.57.

[0089] Table 4 Glass-ceramic composition of Example 4

[0090] Component content (mol%) SiO₂ 47.4 ZnO 0.5 Al₂O₃ 20.5 CaO 0 B₂O₃ 0.3 MgO 0 Na₂O₂ 2 P₂O₅ 5 Li₂O 2.4 ZrO₂ 1.4 K₂O 0 SrO 0.5

[0091] Glass ceramics are prepared by the following steps:

[0092] S1. After melting and refining each raw material at 1580℃ for 4 hours, cast it into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0093] S2. The precursor glass is heated from room temperature to 650°C at a heating rate of 5°C / min, held at that temperature for 0.5h, then heated to 745°C at a heating rate of 5°C / min, held at that temperature for 1h, and cooled to room temperature to obtain glass ceramic.

[0094] Example 5

[0095] This embodiment provides a glass-ceramic with the composition shown in Table 5, wherein the molar percentage ratio of P2O5 to ZrO2 is approximately 1.17.

[0096] Table 5 Glass-ceramic composition of Example 5

[0097] Component content (mol%) Component content (mol%) SiO2 5.8 ZnO 0 Al2O3 15.2 CaO 0 B2O3 0 MgO 0 Na2O2 2.9 P2O5 2.1 Li2O 0 ZrO2 1.8 K2O 0 SrO 0

[0098] Glass ceramics are prepared by the following steps:

[0099] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0100] S2. The precursor glass is heated from room temperature to 800°C at a heating rate of 5°C / min, held at that temperature for 1.5 hours, and then cooled to room temperature to obtain glass ceramic.

[0101] Example 6

[0102] This embodiment provides a glass-ceramic with the composition shown in Table 6, wherein the molar percentage ratio of P2O5 to ZrO2 is 1.3.

[0103] Table 6 Glass-ceramic composition of Example 6

[0104] Component content (mol%) SiO2 45.1 ZnO 0 Al2O3 15 CaO 3 B2O3 1.3 MgO 1.9 Na2O2 1.4 P2O5 1.3 Li2O 10 ZrO2 1 K2O 0 SrO 0

[0105] Glass ceramics are prepared by the following steps:

[0106] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0107] S2. The precursor glass is heated from room temperature to 620°C at a heating rate of 5°C / min, held at that temperature for 1 hour, then heated to 740°C at a heating rate of 5°C / min, held at that temperature for 1 hour, and cooled to room temperature to obtain glass ceramic.

[0108] Example 7

[0109] This embodiment provides a glass-ceramic with the composition shown in Table 7, wherein the molar percentage ratio of P2O5 to ZrO2 is approximately 1.36.

[0110] Table 7 Glass-ceramic composition of Example 7

[0111] Component content (mol%) Component content (mol%) SiO2 43 ZnO 2.9 Al2O3 23 CaO 0 B2O3 0 MgO 2.1 Na2O2 5.3 P2O5 1.9 Li2O 0 ZrO2 1.4 K2O 0.4 SrO 0

[0112] Glass ceramics are prepared by the following steps:

[0113] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0114] S2. The precursor glass is heated from room temperature to 770°C at a heating rate of 5°C / min, held at that temperature for 2 hours, and then cooled to room temperature to obtain glass ceramic.

[0115] Example 8

[0116] This embodiment provides a glass-ceramic with the composition shown in Table 8, wherein the molar percentage ratio of P2O5 to ZrO2 is 3.33.

[0117] Table 8 Glass-ceramic composition of Example 8

[0118] Component content (mol%) SiO2 46.8 ZnO 0 Al2O3 17.3 CaO 0 B2O3 0 MgO 0 Na2O2 4.6 P2O5 1 Li2O 0 ZrO2 0.3 K2O 10 SrO 0

[0119] Glass ceramics are prepared by the following steps:

[0120] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0121] S2. The precursor glass is heated from room temperature to 610°C at a heating rate of 5°C / min, held at that temperature for 0.5h, then heated to 680°C at a heating rate of 5°C / min, held at that temperature for 2h, and cooled to room temperature to obtain glass ceramic.

[0122] Example 9

[0123] This embodiment provides a glass-ceramic with the composition shown in Table 9, wherein the molar percentage ratio of P2O5 to ZrO2 is 1.17.

[0124] Table 9 Glass-ceramic composition of Example 9

[0125] Component content (mol%) SiO2 44.1 ZnO 0 Al2O3 15.5 CaO 0 B2O3 1.5 MgO 0 Na2O2 7.6 P2O5 2.1 Li2O2 ZrO2 1.8 K2O4 SrO 1.4

[0126] Glass ceramics are prepared by the following steps:

[0127] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0128] S2. The precursor glass is heated from room temperature to 730°C at a heating rate of 5°C / min, held at that temperature for 3 hours, and then cooled to room temperature to obtain glass ceramic.

[0129] Example 10

[0130] This embodiment provides a glass-ceramic with the composition shown in Table 10, wherein the molar percentage ratio of P2O5 to ZrO2 is 1.6.

[0131] Table 10 Glass-ceramic composition of Example 10

[0132] Component content (mol%) Component content (mol%) SiO2 43.5 ZnO 0 Al2O3 25 CaO 0 B2O3 0 MgO 0 Na2O2 1.2 P2O5 3.2 Li2O5 5.1 ZrO2 2 K2O 0 SrO 0

[0133] Glass ceramics are prepared by the following steps:

[0134] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0135] S2. The precursor glass is heated from room temperature to 740°C at a heating rate of 5°C / min, held at that temperature for 1 hour, then heated to 830°C at a heating rate of 5°C / min, held at that temperature for 2 hours, and cooled to room temperature to obtain glass ceramic.

[0136] Example 11

[0137] This embodiment provides a glass-ceramic with the composition shown in Table 11, wherein the molar percentage ratio of P2O5 to ZrO2 is 5:3, approximately 1.67.

[0138] Table 11 Glass-ceramic composition of Example 11

[0139] Component content (mol%) Component content (mol%) SiO2 47 ZnO 0 Al2O3 19 CaO 0 B2O3 0 MgO 0 Na2O2 8 P2O5 2.5 Li2O 0 ZrO2 1.5 K2O2 SrO 0

[0140] Glass ceramics are prepared by the following steps:

[0141] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0142] S2. The precursor glass is heated from room temperature to 740°C at a heating rate of 5°C / min, held at that temperature for 1 hour, and then cooled to room temperature to obtain glass ceramic.

[0143] Example 12

[0144] This embodiment provides a glass-ceramic with the composition shown in Table 12, wherein the molar percentage ratio of P2O5 to ZrO2 is approximately 1.92.

[0145] Table 12 Glass-ceramic composition of Example 12

[0146] Component content (mol%) Component content (mol%) SiO2 50 ZnO 0 Al2O3 16 CaO 0 B2O3 2.2 MgO 0 Na2O2 6 P2O5 2.5 Li2O 1 ZrO2 1.3 K2O 1 SrO 0

[0147] Glass ceramics are prepared by the following steps:

[0148] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0149] S2. The precursor glass is heated from room temperature to 650°C at a heating rate of 5°C / min, held at that temperature for 2 hours, then heated to 760°C at a heating rate of 5°C / min, held at that temperature for 0.5 hours, and cooled to room temperature to obtain glass ceramic.

[0150] Example 13

[0151] This embodiment provides a glass-ceramic with the composition shown in Table 13, wherein the molar percentage ratio of P2O5 to ZrO2 is 3.

[0152] Table 13 Glass-ceramic composition of Example 13

[0153] Component content (mol%) Component content (mol%) SiO2 48 ZnO 0 Al2O3 22 CaO 0 B2O3 0 MgO 0 Na2O2 8 P2O5 1.5 Li2O 0 ZrO2 0.5 K2O 0 SrO 0

[0154] Glass ceramics are prepared by the following steps:

[0155] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0156] S2. The precursor glass is heated from room temperature to 680°C at a heating rate of 5°C / min, held at that temperature for 4 hours, and then cooled to room temperature to obtain glass ceramic.

[0157] Example 14

[0158] This embodiment provides a glass-ceramic with the composition shown in Table 14, wherein the molar percentage ratio of P2O5 to ZrO2 is approximately 1.53.

[0159] Table 14 Glass-ceramic Components of Example 14

[0160] Component content (mol%) Component content (mol%) SiO2 4.9 ZnO 0 Al2O3 16.5 CaO 0 B2O3 0 MgO 0 Na2O2 4.1 P2O5 4.6 Li2O 2.8 ZrO2 3 K2O 0 SrO 0

[0161] Glass ceramics are prepared by the following steps:

[0162] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0163] S2. The precursor glass is heated from room temperature to 750°C at a heating rate of 5°C / min, held at that temperature for 0.5 hours, and then cooled to room temperature to obtain glass ceramic.

[0164] Example 15

[0165] This embodiment provides a glass-ceramic with the composition shown in Table 15, wherein the molar percentage ratio of P2O5 to ZrO2 is 5:3, approximately 1.67.

[0166] Table 15 Glass-ceramic composition of Example 15

[0167] Component content (mol%) Component content (mol%) SiO2 5.2 ZnO 0 Al2O3 15.2 CaO 0 B2O3 0 MgO 0 Na2O2 4.2 P2O5 2.5 Li2O 3.6 ZrO2 1.5 K2O 1 SrO 0

[0168] Glass ceramics are prepared by the following steps:

[0169] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0170] S2. The precursor glass is heated from room temperature to 680°C at a heating rate of 5°C / min, held at that temperature for 1 hour, then heated to 700°C at a heating rate of 5°C / min, held at that temperature for 8 hours, and then cooled to room temperature to obtain glass ceramic.

[0171] Comparative Example 1

[0172] This comparative example provides a glass-ceramic with the composition shown in Table 16, wherein the molar percentage ratio of P2O5 to ZrO2 is 7.5.

[0173] Table 16 Glass-ceramic composition of Comparative Example 1

[0174] Component content (mol%) SiO2 4.9%, ZnO 0%, Al2O3 17.6%, CaO 0%, B2O3 0%, MgO 0%, Na2O2 6.7%, P2O5 3%, Li2O 3.3%, ZrO2 0.4%, K2O 0%, SrO 0%

[0175] Glass ceramics are prepared by the following steps:

[0176] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0177] S2. The precursor glass is heated from room temperature to 740°C at a heating rate of 5°C / min, held at that temperature for 1 hour, and then cooled to room temperature to obtain glass ceramic.

[0178] Comparative Example 2

[0179] This comparative example provides a glass-ceramic with the composition shown in Table 17, wherein the molar percentage ratio of P2O5 to ZrO2 is 0.25.

[0180] Table 17 Comparative Example 2 Glass-Ceramic Composition

[0181] Component content (mol%) Component content (mol%) SiO2 5 3 ZnO 0 Al2O3 16.4 CaO 0 B2O3 0 MgO 0 Na2O2 2 P2O5 0.4 Li2O 4.2 ZrO2 1.6 K2O 2.4 SrO 0

[0182] Glass ceramics are prepared by the following steps:

[0183] S1. After melting and refining each raw material at 1600℃ for 4 hours, the raw material is cast into a rectangular slab. The slab is then annealed at 600℃ for 4 hours to obtain the precursor glass.

[0184] S2. The precursor glass is heated from room temperature to 650°C at a heating rate of 5°C / min, held at that temperature for 1 hour, then heated to 700°C at a heating rate of 5°C / min, held at that temperature for 8 hours, and then cooled to room temperature to obtain glass ceramic.

[0185] In the triclinic nepheline glass-ceramic described in this invention, P2O5 primarily promotes phase separation, thereby facilitating crystal precipitation. ZrO2, on the other hand, primarily increases viscosity and forms an ion migration barrier, thus inhibiting crystal precipitation. This invention achieves precise control over the type and size of crystals in the glass-ceramic by adjusting the molar percentages of P2O5 and ZrO2 (with the molar percentage ratio of P2O5 to ZrO2 in the range of 1 to 4, and the P2O5 content being higher than the ZrO2 content), thereby obtaining transparent triclinic nepheline glass-ceramic. In the comparative example, the contents of P2O5 and ZrO2 did not meet the requirements, indicating a failure to grasp the adjustment rules for triclinic nepheline, thus preventing the acquisition of transparent triclinic nepheline glass-ceramic.

[0186] Glass-ceramic characterization and performance testing

[0187] 1. The crystal phase composition and content of the glass ceramics in Examples 1-15 and Comparative Examples 1-2 were analyzed, with the remainder being residual glass phase. The results are shown in Table 18.

[0188] Table 18 Crystal phase composition of glass-ceramics in Examples 1-15 and Comparative Examples 1-2

[0189]

[0190] Note: In the table, "LC" represents low-temperature triclinite and "HC" represents high-temperature triclinite.

[0191] Table 18 shows the crystal phase composition of the glass ceramics in Examples 1-15. As can be seen from Table 18, the crystal phases of the ceramic glass in Examples 1-15 include only triclinic nepheline crystal phase, triclinic nepheline crystal phase and its solid solution (the solid solution includes at least one of NaAlSiO4-SiO2 solid solution, (Na,K)AlSiO4 solid solution, (Na,K)AlSiO4-SiO2 solid solution, R(Al,Si)O4 (where R = Na, K, Mg, Ca, Ba or vacancy), (K,Na)SiO4, CaO, SiO2), triclinic nepheline crystal phase and nepheline crystal phase, triclinic nepheline crystal phase and phosphate phase, and various compositions of triclinic nepheline crystal phase and its solid solution, nepheline phase and phosphate phase.

[0192] X-ray diffraction analysis was performed on the glass-ceramic in Example 3. Figure 2 shows the XRD curve of the glass-ceramic in Example 3. As can be seen from Figure 2, the glass-ceramic in Example 3 contains only one crystal phase, triclinite, with obvious crystal peaks and high crystallinity. That is, the glass-ceramic provided by the present invention can contain only the triclinite crystal phase in its crystal phase composition. The reduction of the phosphate phase is beneficial to the improvement of the chemical stability of the ceramic glass.

[0193] 2. The transmittance, haze, crystallinity, refractive index and crystal size of the glass ceramics in Examples 1-15 and Comparative Examples 1-2 were measured, and the results are shown in Table 19.

[0194] Table 19 Relevant properties of glass ceramics in Examples 1-15 and Comparative Examples 1-2

[0195]

[0196] Table 19 shows the relevant properties of the glass ceramics in Examples 1-15 and Comparative Examples 1-2. As can be seen from Table 19, the crystallinity of the ceramic glass in Examples 1-15 is greater than 30wt%; the crystal size is less than or equal to 94nm; the average transmittance of the 0.7mm thick glass ceramic at wavelengths of 380~780nm is greater than or equal to 66%, and the refractive index is 1.46~1.51.

[0197] Figure 3 shows the transmittance curve of the glass-ceramic in Example 1, and Figure 4 shows the transmittance curve of the glass-ceramic in Example 8. As can be seen from Figures 3 and 4, the glass-ceramics of Example 1 and Example 8 have average transmittances of 89% and 90%, respectively. It is evident that the ceramic glass provided by this invention has high average transmittance and high crystallinity.

[0198] Figure 5 is an SEM image of the glass ceramic in Example 13. As can be seen from Figure 5, there is a clear grid-like microstructure with distinct regional divisions inside the glass ceramic. The diameter of the grid is about 200 nm. The presence of the grid hinders ion migration. The crystal size in Example 13 is only about 46 nm, which shows that it has a clear self-limiting crystallization effect.

[0199] 2. Chemical stability tests were conducted on the glass ceramics in Examples 11-15 and Comparative Examples 1-2:

[0200] The test reference standard is GB / T 32644-2016, and the test results are shown in Table 20. Specifically, the weight loss method was used for testing. A 25mm × 50mm × 1mm sample was prepared and ultrasonically cleaned with neutral, organic solvents and water (none of the cleaning solvents reacted with or corroded the sample). The sample was then dried in an oven at 110℃ for 30 minutes. After weighing using a balance, the sample was placed in a desiccator. The test was conducted according to the acid / alkali concentration, corrosion temperature, and time conditions. After testing, the sample was cleaned with pure water and weighed using a balance. The sample mass was weighed to an accuracy of 0.01mg. The formula for calculating the total surface area is shown in formula (Ⅰ), and the formula for calculating the change in mass per unit area is shown in formula (Ⅱ).

[0201] (Ⅰ);

[0202] Where L: the length of the sample to be tested, in cm;

[0203] W: Width of the sample to be tested, in cm;

[0204] T: Thickness of the sample to be tested, in cm;

[0205] A: Total surface area of ​​the sample to be tested, in cm² 2 ;

[0206] (II);

[0207] Where W1: the original mass of the sample, mg;

[0208] W2: Mass of the sample after the test, mg;

[0209] A: Total surface area of ​​the sample to be tested, in cm² 2 ;

[0210] W A Change in mass per unit area, mg / cm² 2 .

[0211] Chemical stability testing includes:

[0212] (1) Chemical stability 1: Mass loss of glass ceramic after immersion in 10% HF solution at 20℃ for 20 min;

[0213] (2) Chemical stability 2: Mass loss of glass ceramics after immersion in 5% NaOH solution at 95℃ for 6 hours;

[0214] (3) Chemical stability 3: Mass loss of glass ceramics after immersion in 5% HCl solution at 95℃ for 24 hours;

[0215] (4) Chemical stability 4: mass loss of glass ceramics after immersion in 10% NH4F-HF buffer at 20℃ for 20 min.

[0216] Table 20 Chemical stability test results of the glass ceramics in Examples 11-15 and Comparative Examples 1-2

[0217] Example 11 Example 12 Example 13 Example 14 Example 15 Comparative Example 1 Comparative Example 2 Chemical Stability 1 (mg / cm2) 1 1.4 8.5 3 9.1 4 15.7 3 13.1 1 18.4 2 19.30 Chemical Stability 2 (mg / cm2) 4.1 2 3.2 3 3.2 6 4.4 6 3.5 0 5.7 1 5.6 9 Chemical Stability 3 (mg / cm2) 8.2 3 5.9 6 6.7 6 8.3 6 6.8 4 10.4 1 1 1.2 0 Chemical Stability 4 (mg / cm2) 2.1 2 2.0 1 1.5 8 3.4 5 2.6 1 3.5 5 3.7 2

[0218] Table 20 shows the chemical stability test results of the glass ceramics in Examples 11-15 and Comparative Examples 1-2. As can be seen from Table 20, the glass ceramics in Examples 11-15 showed minimal change in mass per unit area after immersion in HF solution, NaOH solution, HCl solution, and NH4F-HF buffer solution. In particular, the glass ceramics in Examples 12 and 13, containing only the triclinic nepheline phase, exhibited better chemical stability (1-4) than the other examples. In Comparative Examples 1-2, the raw materials and process conditions for preparing the glass ceramics were similar to those in Examples 13 and 14, respectively. However, because the crystal phase composition of the glass ceramics consisted of nepheline and phosphate phases, the presence of phosphate increased mass loss, resulting in poorer chemical stability compared to Examples 13 and 14. Therefore, the phosphate-free glass ceramics provided by this invention have better chemical stability, which is beneficial for ensuring yield and production efficiency during production.

[0219] 3. The glass-ceramics in Examples 11-15 were chemically strengthened. Specifically, the glass-ceramics were placed in a mixed salt bath containing NaNO3 and KNO3 for ion exchange. The mass ratio of the two molten salts was 1:1, the ion exchange temperature was 450℃, and the total ion exchange time was 4 hours, resulting in chemically strengthened glass-ceramics. Hardness tests were performed on the glass-ceramics before and after chemical strengthening. The surface compressive stress (CS) and depth of compressive stress (DOL) of the chemically strengthened glass-ceramics were also tested. The hardness test conditions were: maximum load 1.961 N, peak hold time 15 s. The test results are shown in Table 21.

[0220] Table 21. Properties of glass-ceramics before and after chemical strengthening in Examples 11-15

[0221]

[0222] Table 21 shows the properties of glass ceramics before and after chemical strengthening in Examples 11-15. As can be seen from Table 21, chemical strengthening via ion exchange allows large-radius cations to exchange for smaller-radius cations in the glass ceramics. Compared to before strengthening, this increases the Vickers hardness and improves the physical properties of the chemically strengthened glass ceramics. The exchange of potassium cations into the glass ceramics, particularly into the triclinic nepheline crystals, and the exchange of sodium cations or smaller cations out of the glass ceramics, causes the triclinic nepheline crystal cells to expand, generating significant compressive stress and a deep compressive stress layer on the glass ceramic surface. Therefore, the glass ceramics provided by this invention, which are free of or have low phosphate phase content, are beneficial for chemical strengthening treatment.

[0223] In summary, the glass-ceramic provided by this invention is a glass-ceramic with triclinite as the main crystalline phase, comprising ≥30% by mass. It may contain at least one secondary crystalline phase selected from nepheline and phosphate phases, with a secondary crystalline phase mass percentage ranging from 0% to 49%. By reducing the content of secondary crystalline phases (especially phosphate phases), the chemical stability of the glass-ceramic is improved, facilitating subsequent chemical strengthening and cleaning steps, and ensuring high yield and production efficiency during the manufacturing process. In optimal conditions, the crystallinity of the glass-ceramic can reach over 80%, the crystal size is ≤94nm, and the average transmittance in the visible light band can reach over 90%. The crystalline phase composition is diverse and can be controlled according to the heat treatment steps in the preparation method, with short heat treatment time. The chemically strengthened glass-ceramic exhibits excellent physical properties, meeting the application requirements in electronic devices, transportation vehicles, construction, and explosion-proof fields.

[0224] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A glass-ceramic, characterized in that, The product comprises the following components by molar percentage: 43~58 mol% SiO2, 15~27 mol% Al2O3, 20~28 mol% Na2O, 0~10 mol% Li2O, 0~10 mol% K2O, 1~5 mol% P2O5, and 0.3~3 mol% ZrO2. The glass-ceramic is composed of a main crystalline phase, a secondary crystalline phase, and a residual glassy phase; wherein the mass percentage of the main crystalline phase is 30-90%, and the mass percentage of the secondary crystalline phase is 0-49%. The main crystalline phase is one of the following: clinone nepheline phase, clinone nepheline and its solid solution crystalline phase. The subcrystalline phase is at least one of nepheline phase and phosphate phase; wherein the nepheline phase accounts for 0-39% of the mass of the glass ceramic; and the phosphate phase accounts for 0-10% of the mass of the glass ceramic.

2. The glass-ceramic according to claim 1, characterized in that, According to a molar percentage, the molar percentage ratio of P2O5 to ZrO2 in the glass-ceramic is 1 to 4.

3. The glass-ceramic according to claim 1, characterized in that, According to molar percentages, the glass-ceramic contains 15-25 mol% Al2O3, 21-28 mol% Na2O, 1-4 mol% P2O5, and 1-2 mol% ZrO2.

4. The glass-ceramic according to claim 1, characterized in that, According to molar percentages, the glass-ceramic contains 48-58 mol% SiO2, 15-20 mol% Al2O3, 1.5-3.5 mol% P2O5, and 0.3-2 mol% ZrO2.

5. The glass-ceramic according to claim 1, characterized in that, According to molar percentages, the glass-ceramic contains 43-53 mol% SiO2, 18-25 mol% Al2O3, 20-24 mol% Na2O, 2-6 mol% Li2O, 0-2 mol% K2O, and 2.5-5 mol% P2O5.

6. The glass-ceramic according to claim 1, characterized in that, The glass-ceramic further comprises the following components by molar percentage: 0~10 mol% ZnO, 0~10 mol% CaO, 0~10 mol% MgO, 0~10 mol% SrO, and 0~10 mol% B2O3.

7. The glass-ceramic according to any one of claims 1 to 6, characterized in that, The glass-ceramic has a regionally separated grid-like microstructure with a grid diameter of 30~300nm.

8. The glass-ceramic according to any one of claims 1 to 6, characterized in that, When the thickness of the glass-ceramic is 0.7 mm, the average transmittance at wavelengths of 380-780 nm is 65%-93%.

9. The glass-ceramic according to claim 1, characterized in that, The triclinite includes at least one of low-temperature triclinite and high-temperature triclinite. And / or, the solid solution includes at least one of NaAlSiO4-SiO2 solid solution, (Na,K)AlSiO4 solid solution, (Na,K)AlSiO4-SiO2 solid solution, R(Al,Si)O4 (where R = Na, K, Mg, Ca, Ba or a hole), (K,Na)SiO4, CaO, and SiO2.

10. The method for preparing glass-ceramics according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. The components are melted and mixed at 1400~1600℃ to obtain the precursor glass; S2. The precursor glass is heat-treated to obtain the glass ceramic.

11. The preparation method according to claim 10, characterized in that, In step S2, the heat treatment method is selected from one-step ceramization and two-step ceramization. The one-step ceramization process involves heating the precursor glass from room temperature to 620-800°C at a heating rate of 1-10°C / min and holding it at that temperature for 0.5-8 hours to obtain glass-ceramics. The two-step ceramization method is selected from one of the following two methods: (1) The precursor glass is heated from room temperature to 600-650°C at a heating rate of 1-10°C / min, held for 0.5-2 hours, and then heated to 650-750°C at a heating rate of 1-10°C / min, held for 1-8 hours to obtain glass ceramic. (2) The precursor glass is heated from room temperature to 700-800°C at a heating rate of 1-10°C / min, held for 1-2 hours, and then heated to 800-850°C at a heating rate of 1-10°C / min, held for 2-4 hours to obtain glass ceramic.

12. A chemically strengthened glass-ceramic, characterized in that, The glass-ceramic described in any one of claims 1 to 6 is subjected to single or multiple ion exchanges in a mixed salt bath containing NaNO3 and / or KNO3 to obtain the chemically strengthened glass-ceramic.

13. The chemically strengthened glass-ceramic according to claim 12, characterized in that, The chemically strengthened glass-ceramic can form a surface compressive stress ranging from 200 to 3000 MPa, and the depth of the surface compressive stress ranges from 10 to 160 μm.

14. The chemically strengthened glass-ceramic according to claim 12, characterized in that, The ion exchange is performed at a temperature of 400-600℃ for a duration of 1-12 hours.

15. The application of the glass ceramic according to any one of claims 1 to 6, or the chemically strengthened glass ceramic according to any one of claims 12 to 14, in electronic devices, transportation vehicles, buildings, and explosion-proof fields.

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