Low dielectric loss microcrystalline glass and preparation method thereof

Abstract

The application discloses a kind of low dielectric loss microcrystalline glass and preparation method thereof, the microcrystalline glass includes the following components according to mass percentage: SiO2 51%-65%, Al2O3 9%-24%, MgO 4%-17%, P2O5 0.1-4%, Li2O 1-8%, Na2O 1.5-5.9%, K2O 0.01%-3%, Cr2O3 0.1%-2.2%, ZrO2 0.4%-3% and B2O3 0.7-4.5%, it can also include ZnO 0.1-2.07%; the microcrystalline glass is obtained after the above various raw materials are melted, shaped and then heat treated, i.e. low dielectric constant, low dielectric loss microcrystalline glass can be prepared, it is chemically strengthened, so that the microcrystalline glass has high strength, and can be used as the protective cover glass of intelligent communication equipment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of glass-ceramics, and particularly relates to a glass-ceramic with low dielectric loss and a preparation method thereof. BACKGROUND

[0002] With the development of 5G technology and wireless charging technology, higher requirements are put forward for the materials used by mobile terminals, because metal will affect the millimeter wave transmission of 5G communication and hinder wireless charging, and has been unable to adapt to the development needs of future mobile terminals. The mainstream of the current market is glass and ceramic cover plates; although the performance of ceramic back cover is relatively good, it faces the problems of processing difficulty, single color, low yield and the like. The change of 5G communication and the application of wireless charging put forward more stringent requirements for the cover plate materials used by mobile terminals. Most of the smart phone screens on the market use high-aluminum glass, which has improved mechanical properties compared to ordinary glass, but still cannot meet the high strength and high hardness needs of the future development of mobile terminals. Microcrystalline glass is a kind of polycrystalline solid material containing a large amount of microcrystalline phase and glass phase, which is prepared by controlling crystallization during the heating process of base glass with a specific composition. Because of the precipitation of special functional crystals, microcrystalline glass can be endowed with many unique properties, such as high mechanical properties, excellent optical properties and the like.

[0003] CN106242299A discloses a kind of glass-ceramics and glass-ceramic substrate, the glass-ceramics contains SiO2 Component 30.0%~70.0%, Al2O3 Component 8.0%~25.0%, Na2O Component 0%~25.0%, MgO Component 0%~25.0%, ZnO Component 0%~30.0% and TiO2 Component 0%~10.0%, calculated in mole % of oxide, mole ratio [Al2O3 / (MgO+ZnO)] The value is 0.5 or more 2.0 or less, and the crystal phase contains from RAl2O4, RTi2O5, R2TiO4, R2SiO4, RAl2Si2O8 and R2Al4Si5O 18More than one kind selected from the above; the microcrystalline glass or substrate is suitable for optical equipment and other protective components, has high visible light transmittance and good color balance, and also has high strength and is prepared at low cost; but the surface hardness value is still low, and the ion diffusion depth is shallow, which meets the requirements of mobile terminal application. CN105601115A discloses a spinel-based microcrystalline glass and a preparation method thereof, which comprises SiO247.5-70.0%; Al2O310.0-20.0%; MgO 0-22.0%; ZnO 0-12.5%, and the total content of MgO and ZnO is more than 6%, and the crystallized glass contains spinel crystal microcrystals; the Mohs hardness of the microcrystalline glass is 7.5-8, and different colors can be obtained, which overcomes the scratch problem of the wollastonite-based building microcrystalline glass, and prolongs the service life of the building microcrystalline glass; but the optical performance of the microcrystalline glass of the patent application is poor, the visible light transmittance is low, and it cannot be used as a mobile terminal front cover. CN104478219A discloses a nano-spinel microcrystalline glass and a preparation method thereof, the microcrystalline glass comprises 56wt%-62wt% of SiO2; 19wt%-23wt% of Al2O3; 6wt%-15wt% of ZnO; 2wt%-6.5wt% of MgO; 2wt%-6wt% of TiO2; 2wt%-7wt% of ZrO2; Al2O3 in the crystal can form four-coordinated (AlO4) or six-coordinated (AlO6) groups by using aluminum ions, so as to replace the SiO4 tetrahedron of the silicate crystal lattice, thereby improving the mechanical strength of the microcrystalline glass, but the bending strength is only 110MPa, and the Vickers hardness is only 5Gpa, the strength and hardness are low, and the demand of the mobile terminal cannot be met.

[0004] As can be seen from the above, the strength, surface hardness value and stress layer depth of the existing microcrystalline glass material cannot meet the requirements of the 5G mobile terminal for the cover plate material. Therefore, it is particularly important to develop a new type of microcrystalline glass material with high hardness, high impact strength, high transmittance, low dielectric and other properties. SUMMARY

[0005] In view of the above technical problems, the present application provides a low dielectric loss microcrystalline glass and a preparation method thereof, wherein Cr2O3 is added to the basic silicate glass raw material, and part of MgO is replaced by ZnO, and the amount of K2O is reduced to prepare the glass, so that the microcrystalline glass has the advantages of high strength, low dielectric constant and low dielectric loss, and can be used as a protective cover glass for 5G intelligent communication equipment.

[0006] In order to achieve the above object, the present application provides a kind of low dielectric loss glass-ceramics, the glass-ceramics includes the following components according to mass percentage: SiO251%-65%, Al2O39%-24%, MgO 4%-17%, P2O50.1-4%, Li2O 1-8%, Na2O 1.5-5.9%, K2O 0.01%-3%, Cr2O30.1%-2.2%, ZrO20.4%-3% and B2O30.7-4.5%.

[0007] Preferably, the glass-ceramics further includes ZnO 0.1-2.07%.

[0008] Preferably, the amount ratio of (B2O3+P2O5) / ZrO2 is between 0.68-14.9; the amount ratio of (Li2O+Na2O+K2O) / (MgO+ZnO) is between 0.21-2.1.

[0009] Preferably, the Vickers hardness of the glass-ceramics is greater than 690 kgf / mm 2 , the four-point bending strength is greater than 715 Mpa, the dielectric constant is 4-5.5, the dielectric loss is 4.2×10 -4 -6.2×10 -4 -6.2×10 -4 ; the transmittance at 550 nm is 82.7%-91.2%.

[0010] The present application also provides a preparation method of the low dielectric loss glass-ceramics, comprising the following steps:

[0011] (1) weighing each component raw material to obtain a mixture;

[0012] (2) melting the mixture to obtain a glass liquid;

[0013] (3) forming and annealing the glass liquid to prepare a precursor glass;

[0014] (4) preparing the glass-ceramics by heat treating the precursor glass.

[0015] Preferably, the melting temperature in step (2) is 1450-1680 ℃, and the melting time is 4-12 h.

[0016] Preferably, the forming in step (3) is any one of float forming, slot down-draw forming, overflow forming, chemical etching forming and secondary down-draw forming; the annealing temperature is 400 ℃-550 ℃, and the annealing time is 1-6 h.

[0017] Preferably, the heat treatment in step (4) includes nucleation and crystallization.

[0018] Further preferably, the nucleation temperature is 560-630℃, the nucleation time is 1.5-2.5h; the crystallization temperature is 900-1030℃, and the crystallization time is 1-3h.

[0019] Preferably, the chemical strengthening treatment further comprises two first-step ion exchanges and a second-step ion exchange.

[0020] Further preferably, in the first-step ion exchange, the NaNO3 content is ≥40%, the temperature is 450-550℃, and the time is 4-8h; in the second-step ion exchange, the KNO3 content is ≥90%, the temperature is 390-440℃, and the time is 1-3h.

[0021] The present application has the following advantages:

[0022] 1. Na2O is used as the network outer body to reduce the polymerization degree of the glass network structure, reduce the glass melting temperature, and improve the glass melting performance; K2O is used as the glass network outer body to reduce the glass melting temperature, improve the melting quality, and improve the optical performance of the glass; Li2O is used as the glass network outer body to greatly reduce the glass melting temperature, improve the melting quality, and improve the glass forming; MgO is the glass network intermediate body to improve the glass melting; when Li2O, Na2O, and ZnO are introduced together, these oxides support each other in function, adjust the microstructure of the glass-ceramic, and improve the mechanical properties of the glass.

[0023] 2. B2O3 is introduced into the raw materials of the glass-ceramic, which not only plays a fluxing role, but also has the tendency to form boron-oxygen tetrahedra by capturing free oxygen, so that the structure tends to be compact.

[0024] 3. By reasonably matching the chemical components and contents, α=B2O3+P2O5 / ZrO2 is controlled between 0.68-14.9, and β=(Li2O+Na2O+K2O) / (MgO+ZnO) is controlled between 0.21-2.1, so that the prepared glass-ceramic has high strength (Vickers hardness is greater than 690kgf / mm 2 , four-point bending strength is greater than 715Mpa), low dielectric constant (4-5.5), low dielectric loss (4.2×10 -4 -6.2×10 -4 ), and other advantages, and by controlling the components, the prepared glass-ceramic can be effectively ion exchanged, thereby improving the mechanical properties of the glass-ceramic. It can be used as a protective cover glass for 5G intelligent communication equipment.

[0025] 4. Cr2O3 is added to help control the crystallization degree and crystallization size, reduce the difficulty of crystallization, refine the grain size, promote the precipitation of nanoscale crystals in the glass-ceramics, ensure that the glass component is similar to the crystal component, control the crystal size to be 20-67 nm, and thus achieve a higher transmittance. DETAILED DESCRIPTION

[0026] The technical solutions of the present application will be further explained and described below in combination with specific embodiments. It should be noted that the following embodiments are only preferred embodiments of the present application and should not be understood as limiting the present application. The protection scope of the present application should be subject to the content recited in the claims. Modifications and replacements of the technical solutions of the present application made by those skilled in the art without creative labor fall within the protection scope of the present application.

[0027] In the following embodiments: α = B2O3 + P2O5 / ZrO2; β = (Li2O + Na2O + K2O) / (MgO + ZnO)

[0028] Embodiment 1

[0029] (1) High-purity quartz sand, feldspar, soda ash, limestone, dolomite, potassium nitrate, lithium carbonate, zircon, etc. are weighed and mixed to obtain a mixture, the content of SiO2 in the mixture is 59.9%, the content of Al2O3 is 22.46%, the content of MgO is 7.5%, the content of P2O5 is 0.1%, the content of Li2O is 6.09%, the content of Na2O is 1.5%, the content of K2O is 0.01%, the content of Cr2O3 is 1.1%, the content of ZrO2 is 0.44%, and the content of B2O3 is 0.9%; wherein α is 2.05 and β is 1.01;

[0030] (2) The mixture is melted at 1550℃ for 6h to prepare a glass liquid;

[0031] (3) The glass liquid is formed by float method and annealed to prepare a precursor glass;

[0032] (4) The precursor glass is nucleated at 560℃ for 2h, then crystallized at 900℃ for 1h to complete the heat treatment, and a glass-ceramic is prepared.

[0033] Embodiment 2

[0034] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 51%, the content of Al2O3 is 19.3%, the content of MgO is 11.1%, the content of P2O5 is 0.5%, the content of Li2O is 3%, the content of Na2O is 5.9%, the content of K2O is 0.1%, the content of Cr2O3 is 0.2%, the content of ZrO2 is 2.8%, the content of ZnO is 1.64%, and the content of B2O3 is 4.46%; wherein α is 1.77 and β is 0.71;

[0035] The melting temperature in step (2) is 1500°C, and the melting time is 8h;

[0036] The nucleation temperature in step (4) is 580°C, and the microcrystalline glass is prepared.

[0037] Embodiment 3

[0038] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 60%, the content of Al2O3 is 19.35%, the content of MgO is 8%, the content of P2O5 is 0.94%, the content of Li2O is 4.86%, the content of Na2O is 2.36%, the content of K2O is 0.63%, the content of Cr2O3 is 0.3%, the content of ZrO2 is 1.23%, the content of ZnO is 0.43%, and the content of B2O3 is 1.9%; wherein α is 2.31 and β is 0.93;

[0039] The melting temperature in step (2) is 1450°C, and the melting time is 12h;

[0040] The nucleation temperature in step (4) is 570°C, the crystallization temperature is 920°C, and the microcrystalline glass is prepared.

[0041] Embodiment 4

[0042] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 65%, the content of Al2O3 is 11.4%, the content of MgO is 9.2%, the content of P2O5 is 3.7%, the content of Li2O is 2%, the content of Na2O is 2.3%, the content of K2O is 0.3%, the content of Cr2O3 is 0.1%, the content of ZrO2 is 0.48%, the content of ZnO is 2.07%, and the content of B2O3 is 3.45%; wherein α is 14.90 and β is 0.41;

[0043] The melting temperature in step (2) is 1480°C, and the melting time is 8h;

[0044] The nucleation temperature in step (4) is 600°C, the crystallization temperature is 950°C, and the crystallization time is 2h, and the microcrystalline glass is prepared.

[0045] Example 5

[0046] The method and the steps are the same as those of Example 1, wherein the content of SiO2 in step (1) is 64.44%, the content of Al2O3 is 13%, the content of MgO is 8.3%, the content of P2O5 is %, the content of Li2O is 8%, the content of Na2O is 2.1%, the content of K2O is 0.01%, the content of Cr2O3 is 0.2%, the content of ZrO2 is 0.4%, the content of ZnO is 0.08%, and the content of B2O3 is 0.7%; wherein α is 8.68 and β is 1.21;

[0047] The melting temperature in step (2) is 1490°C, and the melting time is 11h;

[0048] The nucleation temperature in step (4) is 620°C, the nucleation time is 2h, the crystallization temperature is 960°C, and the crystallization time is 2h, thereby preparing the glass ceramic.

[0049] Example 6

[0050] The method and the steps are the same as those of Example 1, wherein the content of SiO2 in step (1) is 57.1%, the content of Al2O3 is 21.2%, the content of MgO is 8.8%, the content of P2O5 is 0.2%, the content of Li2O is 4%, the content of Na2O is 1.85%, the content of K2O is 3%, the content of Cr2O3 is 0.3%, the content of ZrO2 is 1%, the content of ZnO is 0.55%, and the content of B2O3 is 2%; wherein α is 2.20 and β is 0.95;

[0051] The melting temperature in step (2) is 1560°C, and the melting time is 8h;

[0052] The nucleation temperature in step (4) is 580°C, the nucleation time is 1.5h, and the crystallization temperature is 930°C, thereby preparing the glass ceramic.

[0053] Example 7

[0054] The method and the steps are the same as those of Example 1, wherein the content of SiO2 in step (1) is 53.9%, the content of Al2O3 is 16.1%, the content of MgO is 9.8%, the content of P2O5 is 4%, the content of Li2O is 4.5%, the content of Na2O is 2.54%, the content of K2O is 0.36%, the content of Cr2O3 is 0.5%, the content of ZrO2 is 3%, the content of ZnO is 1.33%, and the content of B2O3 is 3.97%; wherein α is 2.66 and β is 0.66;

[0055] The melting temperature of step (2) is 1540℃, and the melting time is 7h;

[0056] The nucleation temperature of step (4) is 580℃, the nucleation time is 1.5h, the crystallization temperature is 930℃, and the crystallization time is 1h, to prepare the glass-ceramics.

[0057] Example 8

[0058] The method and steps are the same as example 1, wherein the content of SiO2 in step (1) is 55.14%, the content of Al2O3 is 18.3%, the content of MgO is 10.37%, the content of P2O5 is 1.5%, the content of Li2O is 5.5%, the content of Na2O is 2.3%, the content of K2O is 0.7%, the content of Cr2O3 is 0.7%, the content of ZrO2 is 0.86%, the content of ZnO is 0.6%, and the content of B2O3 is 4.03%; wherein α is 6.43, and β is 0.77.

[0059] The melting temperature of step (2) is 1580℃, and the melting time is 8h;

[0060] The nucleation temperature of step (4) is 580℃, the nucleation time is 2h, the crystallization temperature is 940℃, and the crystallization time is 1h, to prepare the glass-ceramics.

[0061] Example 9

[0062] The method and steps are the same as example 1, wherein the content of SiO2 in step (1) is 54.6%, the content of Al2O3 is 19.27%, the content of MgO is 12.05%, the content of P2O5 is 0.8%, the content of Li2O is 6%, the content of Na2O is 2.5%, the content of K2O is 1.24%, the content of Cr2O3 is 0.8%, the content of ZrO2 is 1.76%, the content of ZnO is 0.58%, and the content of B2O3 is 0.4%; wherein α is 0.68, and β is 0.77.

[0063] The melting temperature of step (2) is 1600℃, and the melting time is 6h;

[0064] The nucleation temperature of step (4) is 620℃, the nucleation time is 2h, the crystallization temperature is 1000℃, and the crystallization time is 3h, to prepare the glass-ceramics.

[0065] Example 10

[0066] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 62.03%, the content of Al2O3 is 14.26%, the content of MgO is 12.55%, the content of P2O5 is 0.1%, the content of Li2O is 1%, the content of Na2O is 1.7%, the content of K2O is 0.2%, the content of Cr2O3 is 1%, the content of ZrO2 is 0.49%, the content of ZnO is 0.67%, and the content of B2O3 is 6%; wherein α is 12.24 and β is 0.22;

[0067] The melting temperature in step (2) is 1620 ℃, and the melting time is 5 h;

[0068] The nucleation temperature in step (4) is 570 ℃, the nucleation time is 2.5 h, the crystallization temperature is 950 ℃, and the crystallization time is 2 h, so as to prepare the glass ceramic.

[0069] Embodiment 11

[0070] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 51.6%, the content of Al2O3 is 17.32%, the content of MgO is 13.63%, the content of P2O5 is 3.36%, the content of Li2O is 4.57%, the content of Na2O is 2.11%, the content of K2O is 3%, the content of Cr2O3 is 1.2%, the content of ZrO2 is 0.73%, the content of ZnO is 2%, and the content of B2O3 is 0.48%; wherein α is 5.26 and β is 0.62.

[0071] The melting temperature in step (2) is 1640 ℃, and the melting time is 4 h;

[0072] The nucleation temperature in step (4) is 570 ℃, the nucleation time is 2.5 h, the crystallization temperature is 940 ℃, and the crystallization time is 1 h, so as to prepare the glass ceramic.

[0073] Embodiment 12

[0074] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 56.65%, the content of Al2O3 is 9.98%, the content of MgO is 14.79%, the content of P2O5 is 0.23%, the content of Li2O is 5.01%, the content of Na2O is 2.83%, the content of K2O is 0.79%, the content of Cr2O3 is 1.5%, the content of ZrO2 is 2.03%, the content of ZnO is 0.75%, and the content of B2O3 is 5.44%; wherein α is 2.79 and β is 0.56.

[0075] The melting temperature in step (2) is 1660 ℃, and the melting time is 4 h;

[0076] The nucleation temperature of step (4) is 630℃, the nucleation time is 2h, the crystallization temperature is 1030℃, and the crystallization time is 3h, to prepare the glass-ceramics.

[0077] Example 13

[0078] The method and steps are the same as example 1, wherein the content of SiO2 in step (1) is 54.16%, the content of Al2O3 is 16.1%, the content of MgO is 14.22%, the content of P2O5 is 0.1%, the content of Li2O is 4.5%, the content of Na2O is 3.1%, the content of K2O is 0.9%, the content of Cr2O3 is 1.6%, the content of ZrO2 is 1.62%, and the content of B2O3 is 1.6%; wherein α is 2.28 and β is 0.6;

[0079] The melting temperature of step (2) is 1680℃, and the melting time is 4h;

[0080] The nucleation temperature of step (4) is 570℃, the nucleation time is 2h, the crystallization temperature is 900℃, and the crystallization time is 1.5h, to prepare the glass-ceramics.

[0081] Example 14

[0082] The method and steps are the same as example 1, wherein the content of SiO2 in step (1) is 56.2%, the content of Al2O3 is 15.78%, the content of MgO is 15.4%, the content of P2O5 is 0.53%, the content of Li2O is 7%, the content of Na2O is 2%, the content of K2O is 0.01%, the content of Cr2O3 is 1.8%, the content of ZrO2 is 0.58%, and the content of B2O3 is 0.7%; wherein α is 2.12 and β is 0.59;

[0083] The melting temperature of step (2) is 1560℃, and the melting time is 8h;

[0084] The nucleation temperature of step (4) is 570℃, the nucleation time is 2h, the crystallization temperature is 950℃, and the crystallization time is 1.5h, to prepare the glass-ceramics.

[0085] Example 15

[0086] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 57.9%, the content of Al2O3 is 10.5%, the content of MgO is 16.16%, the content of P2O5 is 0.1%, the content of Li2O is 4.2%, the content of Na2O is 2.25%, the content of K2O is 2.5%, the content of Cr2O3 is 2%, the content of ZrO2 is 0.88%, the content of ZnO is 0.1%, and the content of B2O3 is 3.41%; wherein α is 3.88 and β is 0.55;

[0087] The melting temperature in step (2) is 1550°C, and the melting time is 8h;

[0088] The nucleation temperature in step (4) is 570°C, the nucleation time is 2.5h, the crystallization temperature is 940°C, and the crystallization time is 2h, to prepare the glass-ceramics.

[0089] Embodiment 16

[0090] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 52.4%, the content of Al2O3 is 12.8%, the content of MgO is 17%, the content of P2O5 is 0.4%, the content of Li2O is 5.11%, the content of Na2O is 5.9%, the content of K2O is 0.27%, the content of Cr2O3 is 2.2%, the content of ZrO2 is 0.5%, the content of ZnO is 2%, and the content of B2O3 is 1.42%; wherein α is 3.64 and β is 0.59;

[0091] The melting temperature in step (2) is 1570°C, and the melting time is 9h;

[0092] The nucleation temperature in step (4) is 570°C, the nucleation time is 2.5h, the crystallization temperature is 930°C, and the crystallization time is 2h, to prepare the glass-ceramics.

[0093] Embodiment 17

[0094] The method and the steps are the same as those in Embodiment 1, wherein the content of SiO2 in step (1) is 57.63%, the content of Al2O3 is 9%, the content of MgO is 14.79%, the content of P2O5 is 0.23%, the content of Li2O is 5.01%, the content of Na2O is 2.83%, the content of K2O is 0.79%, the content of Cr2O3 is 1.5%, the content of ZrO2 is 2.03%, the content of ZnO is 0.75%, and the content of B2O3 is 5.44%; wherein α is 2.79 and β is 0.56;

[0095] The melting temperature in step (2) is 1580°C, and the melting time is 8h;

[0096] The nucleation temperature in step (4) is 630°C, the nucleation time is 2h, the crystallization temperature is 1030°C, and the crystallization time is 3h, to prepare the glass-ceramics.

[0097] Example 18

[0098] The method and steps are the same as Example 1, wherein the content of SiO2 in step (1) is 59.71%, the content of Al2O3 is 24%, the content of MgO is 4%, the content of P2O5 is 0.1%, the content of Li2O is 4%, the content of Na2O is 3.3%, the content of K2O is 0.9%, the content of Cr2O3 is 0.8%, the content of ZrO2 is 1.7%, and the content of B2O3 is 1.49%; wherein α is 0.88 and β is 2.05.

[0099] The melting temperature in step (2) is 1550°C, and the melting time is 9h.

[0100] The nucleation temperature in step (4) is 570°C, the nucleation time is 2h, the crystallization temperature is 920°C, and the crystallization time is 1h, to prepare the glass-ceramics.

[0101] Comparative Example 1

[0102] The method and steps are the same as Example 1, wherein the content of SiO2 in step (1) is 59.4%, the content of Al2O3 is 20%, the content of MgO is 7.5%, the content of P2O5 is 0.1%, the content of Li2O is 6.09%, the content of Na2O is 1.5%, the content of K2O is 0.01%, the content of Cr2O3 is 3%, the content of ZrO2 is 1.5%, and the content of B2O3 is 0.9%; wherein α is 0.60 and β is 1.01.

[0103] The melting temperature in step (2) is 1450°C, and the melting time is 12h.

[0104] The nucleation temperature in step (4) is 560°C, the nucleation time is 2h, the crystallization temperature is 900°C, and the crystallization time is 1h, to prepare the glass-ceramics.

[0105] Comparative Example 2

[0106] The method and the steps are the same as those of Example 1, wherein the content of SiO2 in step (1) is 51.9%, the content of Al2O3 is 17.3%, the content of MgO is 11.1%, the content of P2O5 is 4%, the content of Li2O is 3%, the content of Na2O is 5.9%, the content of K2O is 0.1%, the content of Cr2O3 is 0.2%, the content of ZrO2 is 0.4%, the content of ZnO is 1.64%, and the content of B2O3 is 4.46%; wherein α is 21.15 and β is 0.71;

[0107] The melting temperature in step (2) is 1480°C, and the melting time is 10h;

[0108] The nucleation temperature in step (4) is 580°C, the nucleation time is 2h, the crystallization temperature is 900°C, and the crystallization time is 1h, to prepare the glass-ceramics.

[0109] Comparative Example 3

[0110] The method and the steps are the same as those of Example 1, wherein the content of SiO2 in step (1) is 64%, the content of Al2O3 is 16.35%, the content of MgO is 4%, the content of P2O5 is 0.94%, the content of Li2O is 4.86%, the content of Na2O is 5.36%, the content of K2O is 0.63%, the content of Cr2O3 is 0.3%, the content of ZrO2 is 1.23%, the content of ZnO is 0.43%, and the content of B2O3 is 1.9%; wherein α is 2.31 and β is 2.45;

[0111] The melting temperature in step (2) is 1490°C, and the melting time is 11h;

[0112] The nucleation temperature in step (4) is 570°C, the nucleation time is 2h, the crystallization temperature is 920°C, and the crystallization time is 1h, to prepare the glass-ceramics.

[0113] Comparative Example 4

[0114] The method and the steps are the same as those of Example 1, wherein the content of SiO2 in step (1) is 67.3%, the content of Al2O3 is 11.4%, the content of MgO is 9.2%, the content of P2O5 is 3.7%, the content of Li2O is 1%, the content of Na2O is 1%, the content of K2O is 0.3%, the content of Cr2O3 is 0.1%, the content of ZrO2 is 0.48%, the content of ZnO is 2.07%, and the content of B2O3 is 3.45%; wherein α is 14.90 and β is 0.20;

[0115] The melting temperature in step (2) is 1560°C, and the melting time is 8h;

[0116] The nucleation temperature in step (4) is 600°C, the nucleation time is 2h, the crystallization temperature is 950°C, and the crystallization time is 2h, to prepare the glass-ceramics.

[0117] Comparative Example 5

[0118] The method and steps are the same as in Example 1, wherein the content of SiO2 in step (1) is 65.64%, the content of Al2O3 is 13%, the content of MgO is 8.3%, the content of P2O5 is 2.77%, the content of Li2O is 7%, the content of Na2O is 2.1%, the content of K2O is 0.01%, the content of ZrO2 is 0.4%, the content of ZnO is 0.08%, and the content of B2O3 is 0.7%; wherein α is 8.68 and β is 1.09.

[0119] The melting temperature in step (2) is 1540°C, and the melting time is 7h.

[0120] The nucleation temperature in step (4) is 620°C, the nucleation time is 1.5h, the crystallization temperature is 960°C, and the crystallization time is 2h, to prepare the glass-ceramics.

[0121] Comparative Example 6

[0122] The method and steps are the same as in Example 1, wherein the content of SiO2 in step (1) is 57.1%, the content of Al2O3 is 18.5%, the content of MgO is 8.8%, the content of P2O5 is 0.2%, the content of Li2O is 4%, the content of Na2O is 1.85%, the content of K2O is 3%, the content of Cr2O3 is 3%, the content of ZrO2 is 1%, the content of ZnO is 0.55%, and the content of B2O3 is 2%; wherein α is 2.20 and β is 0.95.

[0123] The melting temperature in step (2) is 1580°C, and the melting time is 8h.

[0124] The nucleation temperature in step (4) is 580°C, the nucleation time is 1.5h, the crystallization temperature is 930°C, and the crystallization time is 1h, to prepare the glass-ceramics.

[0125] Result detection: the properties of the glass-ceramics prepared in the above examples and comparative examples are detected, wherein the conventional performance parameters are shown in Table 1, the thermal properties and mechanical properties are shown in Table 2:

[0126] Table 1 Performance parameters of the glass-ceramics

[0127]

[0128] Table 2 Thermal properties and mechanical properties of the glass-ceramics

[0129]

[0130] Example 18

[0131] The glass-ceramic prepared in Example 7 was chemically strengthened at different concentrations of sodium nitrate and potassium nitrate, respectively, by a two-step strengthening process. The strengthening conditions are shown in Table 3, and the strengthening results are shown in Table 4:

[0132] Table 3 Strengthening conditions

[0133]

[0134] Table 4 Stress results after strengthening

[0135]

Claims

1. A low dielectric loss microcrystalline glass, characterized in that: The microcrystalline glass comprises the following components by mass percentage: SiO2 51%-65%, Al2O3 9%-24%, MgO 4%-17%, P2O5 0.1-4%, Li2O 1-8%, Na2O 1.5-5.9%, K2O 0.01%-3%, Cr2O3 0.1%-2.2%, ZrO2 0.4%-3%, and B2O3 0.7-4.5%; The microcrystalline glass also contains 0.1-2.07% ZnO; The ratio of (B2O3+P2O5) / ZrO2 is between 0.68 and 14.9; the ratio of (Li2O+Na2O+K2O) / (MgO+ZnO) is between 0.21 and 2.

1.

2. A method for preparing a low dielectric loss microcrystalline glass as described in claim 1, characterized in that: Includes the following steps: (1) Weigh each component raw material and mix them to obtain a mixture; (2) Melt the mixture to obtain molten glass; (3) The molten glass is shaped and annealed to produce precursor glass; (4) The precursor glass is heat-treated to prepare microcrystalline glass.

3. The preparation method according to claim 2, characterized in that: The melting temperature in step (2) is 1450-1680℃ and the melting time is 4-12h.

4. The preparation method according to claim 2, characterized in that: The molding process described in step (3) is any one of float molding, slot-down molding, overflow molding, chemical etching molding, and secondary slot-down molding.

5. The preparation method according to claim 2, characterized in that: The heat treatment described in step (4) includes nucleation and crystallization.

6. The preparation method according to claim 5, characterized in that: The nucleation temperature is 560-630℃, and the nucleation time is 1.5-2.5h; the crystallization temperature is 900-1030℃, and the crystallization time is 1-3h.

7. The preparation method according to claim 2, characterized in that: It also includes chemical enhancement treatment, which includes a first step of ion exchange and a second step of ion exchange.

8. The preparation method according to claim 7, characterized in that: In the first step of ion exchange, the NaNO3 content is ≥40%, the temperature is 450-550℃, and the time is 4-8h; in the second step of ion exchange, the KNO3 content is ≥90%, the temperature is 390-440℃, and the time is 1-3h.

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