Crystallized glass and preparation method therefor

Abstract

Disclosed are a crystallized glass and a preparation method therefor. The crystallized glass contains the following components, calculated by mass percentage of oxides: SiO2 accounts for 60.0%-70.0%, P2O5 accounts for 1.0%-5.0%, Al2O3 accounts for 0.1%-10.0%, Li2CO3 accounts for 3.1%-9.99%, K2CO3 accounts for 1.0%-3.0%, Na2CO3 accounts for 5.1%-12.0%, MgO accounts for 1.0%-5.0%, TiO2 accounts for 0.01%-0.09%, ZrO2 accounts for 1.0%-10.0%, SrO accounts for 1.0%-2.0%, La2O3 accounts for 0.1%-0.9%, Y2O3 accounts for 0.1%-0.9%, Nb2O5 accounts for 1.0%-2.0%, Ta2O5 accounts for 1.0%-2.0%, WO3 accounts for 0.1%-0.9%, Gd2O3 accounts for 0.1%-0.9%, Bi2O3 accounts for 0.1%-0.9%, and TeO2 accounts for 0.1%-0.9%. The crystallized glass of the present invention contains a specified quantity of components that increase a compressive stress layer and stress depth. By chemically strengthening the compressive stress layer by using a mixed acid or by changing the order of single salt components, the surface compressive stress of the compressive stress layer can be increased while the central compressive stress can be reduced. Furthermore, the glass has strong impact resistance, and even if the glass is damaged by an impact, it is difficult to break into fine particles.

Description

A crystalline glass and its preparation method Technical Field

[0001] This invention relates to the field of glass product technology, specifically to a crystallized glass and its preparation method. Background Technology

[0002] In consumer products, cover glass is used in portable electronic devices such as smartphones, tablets, and personal computers to protect the display screen. Protective glass is also used in automotive optics to protect lenses. Furthermore, in recent years, there has been a demand for these materials in the casings of electronic devices. Moreover, there is an increasing need for materials with high hardness and high light transmittance so that these devices can withstand harsh use. Therefore, this invention provides a method for preparing a crystalline glass that meets these requirements.

[0003] Summary of the Invention

[0004] The purpose of this invention is to provide a crystallizing glass to solve the problems mentioned in the background section. To achieve the above objective, this invention provides the following technical solution:

[0005] A crystalline glass, comprising the following components by mass percentage of oxides:

[0006] The composition is as follows: SiO2 60.0%–70.0%, P2O5 1.0%–5.0%, Al2O3 0.1%–10.0%, Li2CO3 3.1%–9.99%, K2CO3 1.0%–3.0%, Na2CO3 5.1%–12.0%, MgO 1.0%–5.0%, TiO2 0.01%–0.09%, ZrO2 1.0%–1 0.0%, SrO 1.0%–2.0%, La2O3 0.1%–0.9%, Y2O3 0.1%–0.9%, Nb2O5 1.0%–2.0%, Ta2O5 1.0%–2.0%, WO3 0.1%–0.9%, Gd2O3 0.1%–0.9%, Bi2O3 0.1%–0.9%, TeO2 0.1%–0.9%.

[0007] Furthermore, the main crystalline phases of the crystal glass are quartz, lithium disilicate, and petalite.

[0008] Preferably, the main crystalline phase has a grain diameter of 1–100 nm and a crystallinity of 30–80%.

[0009] This invention also provides a method for preparing crystal glass, comprising the following steps:

[0010] Raw materials are uniformly mixed, melted, and cooled to form a sheet of glass. The raw materials consist of the following components by weight percentage:

[0011] SiO2 accounts for 60.0%–70.0%, P2O5 accounts for 1.0%–5.0%, Al2O3 accounts for 0.1%–10.0%, Li2CO3 accounts for 3.1%–9.99%, K2CO3 accounts for 1.0%–3.0%, Na2CO3 accounts for 5.1%–12.0%, MgO accounts for 1.0%–5.0%, TiO2 accounts for 0.01%–0.09%, and ZrO2 accounts for 0.01%–0.09%. The composition of the components is as follows: 1.0%–10.0%, SrO 1.0%–2.0%, La2O3 0.1%–0.9%, Y2O3 0.1%–0.9%, Nb2O5 1.0%–2.0%, Ta2O5 1.0%–2.0%, WO3 0.1%–0.9%, Gd2O3 0.1%–0.9%, Bi2O3 0.1%–0.9%, and TeO2 0.1%–0.9%.

[0012] The original glass is subjected to thermal nucleation and crystal growth processes to obtain crystalline glass.

[0013] Preferably, mixing is carried out in a mixer for 5-60 minutes; melting is performed using a quartz crucible, zircon crucible, or platinum crucible at a temperature of 1500-1700℃.

[0014] Preferably, the temperature for thermal nucleation treatment is 500℃~850℃, and the time for thermal nucleation treatment is 30~4000min; the temperature for crystal growth treatment is 500℃~850℃, and the time for crystal growth treatment is 30~1800min.

[0015] Furthermore, the crystal glass is ground and polished, and the ground and polished crystal glass is immersed in a potassium or sodium salt solution; a compressive stress layer is formed on the surface layer of the crystal glass by heat strengthening treatment or ion implantation method.

[0016] Preferably, the soaking time is 1 to 720 minutes, more preferably 300 to 500 minutes; the temperature of the salt solution is 350°C to 550°C; the salt solution can be potassium nitrate or sodium nitrate.

[0017] Preferably, the specific method of heat strengthening treatment is as follows: after heating to 300℃~600℃, rapid cooling is performed to form a compressive stress layer generated by the temperature difference between the surface and the interior of the crystalline glass.

[0018] Preferably, the ion implantation method involves bombarding the surface of the crystal glass with ions to implant ions into the surface of the crystal glass without damaging the acceleration energy and acceleration voltage of the crystal glass surface, thereby forming a compressive stress layer.

[0019] The beneficial effects of the present invention are as follows: The crystal glass of the present invention contains a specified number of components that increase the compressive stress layer and stress depth. By chemically strengthening the compressive stress layer with mixed acid or by changing the order of single salt components, the surface compressive stress of the compressive stress layer can be increased while the central compressive stress is reduced. It also has strong impact resistance, and even if the glass is broken by impact, it is difficult to break it into fine particles. Detailed Implementation

[0020] The composition and preparation method of the present invention will be further described in detail below with reference to specific embodiments. However, the present invention is not limited to the following implementation methods and embodiments. Within the scope of the purpose of the present invention, appropriate modifications can be made for implementation.

[0021] In this specification, unless otherwise specified, the content of each component is expressed as a percentage by mass converted from oxides. Here, "oxide conversion" refers to the amount of each oxide in the crystal glass, expressed as a percentage by mass, assuming that all the components of the crystal glass decompose and transform into oxides, with the total mass of these oxides set at 100% by mass. In this specification, 0% means a content of 0%.

[0022] This invention provides a crystalline glass containing the following components, based on the mass percentage of oxides:

[0023] The composition is as follows: SiO2 60.0%–70.0%, P2O5 1.0%–5.0%, Al2O3 0.1%–10.0%, Li2CO3 3.1%–9.99%, K2CO3 1.0%–3.0%, Na2CO3 5.1%–12.0%, MgO 1.0%–5.0%, TiO2 0.01%–0.09%, ZrO2 1.0%–1 0.0%, SrO 1.0%–2.0%, La2O3 0.1%–0.9%, Y2O3 0.1%–0.9%, Nb2O5 1.0%–2.0%, Ta2O5 1.0%–2.0%, WO3 0.1%–0.9%, Gd2O3 0.1%–0.9%, Bi2O3 0.1%–0.9%, TeO2 0.1%–0.9%.

[0024] SiO2 is a glass-forming component that forms the network structure of glass. On the other hand, if the SiO2 content is insufficient, the resulting glass lacks chemical durability and has poor devitrification resistance. In this invention, the upper limit of the SiO2 content is preferably ≤70.0%, more preferably ≤69.0%, further preferably ≤68.0%, and most preferably ≤66.0%; the lower limit of the SiO2 content is ≥60.0%, more preferably ≥62.0%, further preferably ≥63.0%, and most preferably ≥64.0%.

[0025] A P2O5 content ≥1.0% acts as a nucleating agent during glass crystallization and also improves the glass's resistance to devitrification. In particular, reducing the P2O5 content to below 5.0% improves the glass's melting properties while also reducing its devitrification tendency. In this invention, the upper limit of the P2O5 content is ≥5.0%, more preferably ≥4.5%, and most preferably ≥4.0%.

[0026] When the Al2O3 content is ≥0.1%, it can increase the viscosity of the glass during melting and improve its chemical durability. In particular, reducing the Al2O3 content to ≤10.0% can improve the melting performance of the glass while also reducing its devitrification tendency. In this invention, the upper limit of the Al2O3 content is preferably ≤10.0%, more preferably ≤5.0%, and most preferably ≤3.0%.

[0027] Li₂CO₃, K₂CO₃, and Na₂CO₃ participate in ion exchange during chemical fortification. Li₂CO₃, K₂CO₃, and Na₂CO₃ act as nucleating agents (auxiliaries) for crystallization, exchange substances with (K⁺) and (Li⁺) ions during ion exchange, reduce dissolution viscosity, and prevent dissolution depermeability (depermeability-resistant components). However, excessive content may deteriorate chemical durability and impermeability. In this invention, the upper limit for Li₂CO₃ is ≤9.99%, and the lower limit is ≥5.1%; the upper limit for K₂CO₃ is ≤1.0%, and the lower limit is ≥3.0%; and the upper limit for Na₂CO₃ is ≤12.0%, and the lower limit is ≥5.1%.

[0028] MgO has the effect of reducing the viscosity of molten glass during glass melting. Preferably, the upper limit of MgO is ≤5.0% and the lower limit is ≥1.0%.

[0029] TiO2 has the effect of increasing the strain point of glass and improving its chemical durability. Preferably, the upper limit of TiO2 is ≤0.09% and the lower limit is ≥0.01%.

[0030] ZrO2 has the effect of increasing the strain point of glass and improving its chemical durability. Preferably, the upper limit of ZrO2 is ≤10.0% and the lower limit is ≥1.0%.

[0031] SrO, when coexisting with MgO, reduces the high-temperature viscosity of molten glass and inhibits devitrification. The upper limit of SrO is ≤2.0%, and the lower limit is ≥1.0%.

[0032] La2O3 and Nb2O5 have the effect of increasing the refractive index of glass. The upper limit of La2O3 is ≤0.9% and the lower limit is ≥0.1%; the upper limit of Nb2O5 is ≤2.0% and the lower limit is ≥1.0%.

[0033] Y2O3 works in conjunction with Ta2O5, WO3, and TeO2 to achieve good results. Specifically, the upper limit of Y2O3 is ≤0.9%, and the lower limit is ≥0.1%; the upper limit of Ta2O5 is ≤2.0%, and the lower limit is ≥1.0%; the upper limit of WO3 is ≤0.9%, and the lower limit is ≥0.1%; and the upper limit of TeO2 is ≤0.9%, and the lower limit is ≥0.1%. Using the above combinations of raw materials within these ranges can improve the strength and elastic modulus of glass.

[0034] Gd2O3 has the effect of reducing devitrification during glass melting and also acts as a nucleation aid. The upper limit of Gd2O3 is ≤0.9% and the lower limit is ≥0.1%.

[0035] Bi2O3 can reduce the viscosity of molten glass during melting and improve its solubility. The upper limit of Bi2O3 is ≤0.9% and the lower limit is 0.1%.

[0036] The crystalline glass framework structure of the present invention is as follows:

[0037] SiO 2- The Al2O3-Li2CO3-ZrO2-TiO2-P2O5 (MgO-SrO-La2O3-Y2O3-Nb2O5-Ta2O5-WO3-Gd2O3-Bi2O3-TeO2) structure exhibits robustness. Based on this framework, the crystalline glass contains a specified amount of components that increase compressive stress layers and stress depth, such as K2CO3 and Na2CO3. These components do not affect the framework structure after ion exchange and possess higher physical strength properties. Furthermore, since it contains no coloring materials, it remains colorless and transparent. In summary, the composition of this invention produces a hard, colorless, and transparent crystalline glass.

[0038] In one embodiment, the main crystalline phase of the crystal glass is cristobalite, lithium disilicate (Li2O5Si2), and lepidolite (LiAlSi4O10), and the grain diameter of the main crystalline phase is 1-100 nm and the crystallinity is 30-80%.

[0039] The present invention also provides a method for preparing the above-described crystal glass, comprising the following steps:

[0040] S1: The raw materials are uniformly mixed, melted, and cooled to form a sheet of glass. The raw materials consist of the following components by weight percentage:

[0041] The composition is as follows: SiO2 60.0%–70.0%, P2O5 1.0%–5.0%, Al2O3 0.1%–10.0%, Li2CO3 3.1%–9.99%, K2CO3 1.0%–3.0%, Na2CO3 5.1%–12.0%, MgO 1.0%–5.0%, TiO2 0.01%–0.09%, ZrO2 1.0%–1 0.0%, SrO 1.0%–2.0%, La2O3 0.1%–0.9%, Y2O3 0.1%–0.9%, Nb2O5 1.0%–2.0%, Ta2O5 1.0%–2.0%, WO3 0.1%–0.9%, Gd2O3 0.1%–0.9%, Bi2O3 0.1%–0.9%, TeO2 0.1%–0.9%;

[0042] In one embodiment, mixing is carried out in a mixer for 5-60 minutes at a speed of 1.0-30 rpm. Melting is performed using a quartz crucible, zircon crucible, or platinum crucible at a temperature of 1500-1700°C for 2-72 hours. During cooling and shaping, the temperature is reduced to between 1000°C and 1450°C, and the mixture is poured into a mold and slowly cooled to produce a sheet of glass.

[0043] S2: The original glass sheet is subjected to thermal nucleation treatment and crystal growth treatment to obtain crystalline glass;

[0044] In one embodiment: the temperature of the thermal nucleation treatment is 500℃~850℃, and the time of the thermal nucleation treatment is 30~4000min; the temperature of the crystal growth treatment is 500℃~850℃, and the time of the crystal growth treatment is 30~1800min.

[0045] In a further embodiment of the present invention, the preparation method further includes step S3:

[0046] S3: Grinding and polishing the crystallized glass;

[0047] In a further embodiment of the present invention, the preparation method further includes step S4:

[0048] S4: Immerse the ground and polished crystal glass in a solution containing potassium or sodium salts;

[0049] In one embodiment: the soaking time is 1 to 720 min, preferably 300 to 500 min; the temperature of the salt solution is 350°C to 550°C; the salt solution can be potassium nitrate (KNO3) or sodium nitrate (NaNO3);

[0050] S4: A compressive stress layer is formed on the surface layer of the crystalline glass by thermal strengthening treatment or ion implantation.

[0051] In one embodiment: The specific method of thermal strengthening treatment is to heat the glass to 300°C to 600°C and then rapidly cool it to form a compressive stress layer caused by the temperature difference between the surface and the interior of the crystal glass; the ion implantation method is to bombard the surface of the crystal glass with ions without damaging the acceleration energy and acceleration voltage of the crystal glass surface, thereby implanting ions into the surface of the crystal glass to form a compressive stress layer.

[0052] The following experiments demonstrate the beneficial effects of the present invention. The specific experimental steps are as follows:

[0053] The raw materials are mixed and fed into a platinum crucible, and melted in an electric furnace at 1500℃~1700℃ for 2~72 hours. The molten raw materials are then stirred to homogenize them. The temperature is then reduced to between 1000℃~1450℃, poured into a mold, and slowly cooled to produce the original glass sheet.

[0054] The raw glass was subjected to a one-step heat treatment (500–850 °C, 5 hours) to nucleate and crystallize, producing a crystalline glass. The resulting crystalline glass was analyzed using a 200 kV field emission transmission electron microscope (FE-TEM, JEOL, model JEM2100F). The results showed precipitated crystals with an average crystal diameter between 1 and 100 nm. Further lattice image confirmation through electron diffraction and EDX analysis confirmed that cristobalite, lithium disilicate (Li₂O₅Si₂), and petalite (LiAlSi₄O₁₀) were the main crystalline phases. Transmission electron microscopy was used to determine the 180 × 180 nm crystal size. 2 The crystal diameter of the crystalline particles within the region is calculated and the average value is determined.

[0055] The prepared crystallized glass substrate is cut and ground, and then polished face-to-face to obtain a substrate with a thickness of 0.50 mm.

[0056] Crystalline glass is obtained by chemical strengthening after parallel polishing;

[0057] Evaluation and stress measurement of crystal glass:

[0058] The following physical properties of the obtained crystalline glass were measured. The results are listed in Tables 1 to 3, including specific gravity (d), surface compressive stress (CS), and thickness of the compressive stress layer (stress depth DOL_zero).

[0059] For the crystal glasses of Examples 1-15 and Comparative Examples 1-2 (where the comparative examples are experimental results of crystal glasses obtained using prior art formulations), the effects of the present invention are generally achieved in crystal glasses that meet CS 666.8-1156.7 MPa and DOL_zero 138.9-200 μm. The surface compressive stress (CS) value and the thickness of the compressive stress layer (stress depth DOL) were measured using a glass surface stress gauge FSM-6000LE series manufactured by Orihara Manufacturing Co., Ltd., and synthesized values ​​measured on a Li+ ion substitution measuring instrument SLP-1000 or 2000. For the light source of the measuring machine used for CS measurement, a light source with a wavelength of 596 nm was selected for measurement. The refractive index value at 596 nm was used for CS measurement. The refractive index value at a wavelength of 596 nm was calculated from the refractive index measurements at the wavelengths of C, d, F, and g lines using the second-order approximation method according to the V-block method specified in JIS B7071-2:2018. The central compressive stress (CT) value is determined by curve analysis.

[0060] Table 1

[0061] Table 2

[0062] Table 3

[0063] As can be seen from the table above, the crystal glass obtained by adopting the scheme of the present invention meets the requirements of CS666.8-1156.7Mpa and DOL_zero138.9-200um. This can achieve the technical effect of increasing the surface compressive stress of the compressive stress layer, reducing the central compressive stress, and having strong impact resistance. Even if the glass is damaged by impact, it is difficult to break it into fine particles.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. The scope of protection of the present invention should be determined by the scope of the claims. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A crystallized glass, comprising, in terms of mass percentage of oxides: SiO2 60.0% to 70.0%, P2O5 1.0% to 5.0%, Al2O3 0.1% to 10.0%, Li2CO3 3.1% to 9.99%, K2CO3 1.0% to 3.0%, Na2CO3 5.1% to 12.0%, MgO 1.0% to 5.0%, TiO2 0.01% to 0.09%, ZrO2 1.0% to 10.0%, SrO 1.0% to 2.0%, La2O3 0.1% to 0.9%, Y2O3 0.1% to 0.9%, Nb2O5 1.0% to 2.0%, Ta2O5 1.0% to 2.0%, WO3 0.1% to 0.9%, Gd2O3 0.1% to 0.9%, Bi2O3 0.1% to 0.9%, and TeO2 0.1% to 0.9%. The main crystal phase of the crystallized glass is cristobalite, lithium disilicate, and petalite.

2. The crystallized glass of claim 1, wherein: The grain diameter of the main crystal phase is 1 to 100 nm, and the crystallinity is 30 to 80%.

3. The crystalline glass of claim 1, wherein: The method comprises the following steps:

4. A method of making a crystallized glass, characterized by, The raw materials are uniformly mixed, melted, and cooled to form a raw glass sheet, and the raw materials comprise the following components in terms of weight percentage: SiO2 60.0% to 70.0%, P2O5 1.0% to 5.0%, Al2O3 0.1% to 10.0%, Li2CO3 3.1% to 9.99%, K2CO3 1.0% to 3.0%, Na2CO3 5.1% to 12.0%, MgO 1.0% to 5.0%, TiO2 0.01% to 0.09%, ZrO2 1.0% to 10.0%, SrO 1.0% to 2.0%, La2O3 0.1% to 0.9%, Y2O3 0.1% to 0.9%, Nb2O5 1.0% to 2.0%, Ta2O5 1.0% to 2.0%, WO3 0.1% to 0.9%, Gd2O3 0.1% to 0.9%, Bi2O3 0.1% to 0.9%, and TeO2 0.1% to 0.9%; The raw glass sheet is subjected to heat nucleation treatment and crystal growth treatment to obtain the crystallized glass. The mixing is performed in a blender, the mixing time is 5 to 60 minutes, the blender speed is 1.0 to 30 rpm; the melting is performed using a quartz crucible, a zircon crucible, or a platinum crucible, the melting temperature is 1500 to 1700 °C, the melting time is 2 to 72 hours, and the cooling forming is performed by reducing the temperature to 1000 °C to 1450 °C, pouring the glass into a mold, and slowly cooling to produce the raw glass sheet.

5. The method of claim 4, wherein the glass is crystallized by heating the glass to a temperature in the range of 700°C to 800°C. The heat nucleation treatment temperature is 500 °C to 850 °C, and the heat nucleation treatment time is 30 to 4000 minutes; the crystal growth treatment temperature is 500 °C to 850 °C, and the crystal growth treatment time is 30 to 1800 minutes.

6. The method of claim 4, wherein the glass is crystallized by heating the glass to a temperature in the range of 700°C to 800°C. ​ 7. The method of claim 4 wherein the glass is crystallized by heating the glass to a temperature in the range of 700°C to 800°C for a period of time in the range of 1 hour to 10 hours. The crystallized glass is ground and polished, and the ground and polished crystallized glass is soaked in a solution of potassium or sodium salt. A compressive stress layer is formed on the surface layer of the crystallized glass by thermal strengthening or ion implantation.

8. The method of claim 7, wherein the glass is crystallized by heating the glass to a temperature in the range of 700°C to 800°C. The soaking time is 1-720 minutes, preferably 300-500 minutes, and the temperature of the salt solution is 350-550℃. The salt solution can be potassium nitrate or sodium nitrate.

9. The method of claim 7, wherein the glass is crystallized by heating the glass to a temperature in the range of 700°C to 800°C for a period of time in the range of 1 hour to 10 hours. The thermal strengthening method is as follows: the crystallized glass is heated to 300-600℃ and then rapidly cooled to form a compressive stress layer due to the temperature difference between the surface and the interior of the crystallized glass.

10. The method of claim 7, wherein the glass is crystallized by heating the glass to a temperature in the range of 700°C to 800°C. The ion implantation method is as follows: ions are used to impact the surface of the crystallized glass at an acceleration energy and acceleration voltage that do not damage the surface of the crystallized glass, so that the ions are implanted into the surface of the crystallized glass to form a compressive stress layer.

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