Anti-dazzle high aluminosilicate microcrystalline glass containing nano nepheline phase as well as preparation method and application of anti-dazzle high aluminosilicate microcrystalline glass

Abstract

The invention relates to the field of tempered glass, and particularly discloses anti-dazzle high aluminosilicate microcrystalline glass containing a nano nepheline phase as well as a preparation method and application of the anti-dazzle high aluminosilicate microcrystalline glass. The glass ceramic is prepared from the following components in percentage by weight: 20 to 1.5 percent of SiO2, Al2O3, Na2O, K2O, P2O5, MgO and ZrO; wherein the mass percentage content of P2O5 is 4.5 to 14.0 percent, and the weight ratio of Al2O3 to P2O5 is 0.5 to 4.4. According to the method, annealing is controlled after melting forming, and a single nepheline phase with the average size smaller than 100 nm is directionally separated out in a glass matrix. After the material is subjected to chemical strengthening, the stress layer depth larger than 50 microns and the surface compressive stress larger than 750 MPa can be obtained, the anti-falling performance is remarkably improved, and meanwhile the high light transmittance of 90% or above is kept. In addition, by means of selective etching of acid liquor on the split-phase structure, uniform spherical pits with the roughness being 0.05-0.4 micrometer can be formed in the surface of the split-phase structure, and the excellent anti-dazzle effect is achieved. The microcrystalline glass is suitable for cover plate glass in various fields of mobile terminals, vehicle-mounted displays and the like.

Description

Technical Field

[0001] This application relates to the field of tempered glass, and more specifically, to a high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare properties, as well as its preparation method and uses. Background Technology

[0002] Chemically strengthened glass, due to its superior mechanical strength, excellent optical transparency, and good surface abrasion resistance, has become the preferred material for screen covers in many fields such as mobile terminals, automotive displays, and wearable devices. Its strengthening mechanism essentially involves forming a compressive stress layer on the glass surface through an ion exchange process to inhibit crack propagation and improve impact resistance. However, under the dual pressure of the industry's continuous pursuit of higher performance and lower costs, existing mainstream technologies face significant bottlenecks, particularly in balancing high drop resistance with low cost and achieving a high-quality anti-glare (AG) surface, where an irreconcilable contradiction exists.

[0003] Specifically, the cover glass currently used for chemical strengthening is mainly divided into the following three systems, and their technical limitations are as follows: (1) High-alumina silicate glass: This system can achieve high surface compressive stress (>700 MPa) through ion exchange due to its high Al2O3 content. However, the dense alumina network severely limits the diffusion depth of alkali metal ions, resulting in a shallow stress layer depth (DOL) (approximately 30-45 μm). The shallow stress layer makes it easily broken down in drop impacts, thus limiting its drop resistance (e.g., drop height is often less than 0.5 m), making it difficult to meet the increasingly demanding requirements for terminal reliability. Although its raw material cost is relatively low, its performance is insufficient.

[0004] (2) Lithium aluminosilicate glass: This system utilizes Li + / Na + Expansion allows for the creation of a deeper stress layer (DOL > 80μm), significantly improving drop resistance. However, the high cost and volatile price of its core raw material, lithium compounds, substantially increase overall production costs, hindering its widespread adoption in cost-effective products.

[0005] (3) Glass-ceramics: Through the precipitation of crystalline phases, they have extremely high intrinsic toughness and strength, exhibiting the best drop resistance. However, their preparation requires a complex melting, precision crystallization, cutting and polishing process, resulting in the highest production cost. Currently, they are only used in a few high-end devices.

[0006] Furthermore, anti-glare surfaces typically require the formation of a uniform micro-rough structure on the glass surface through an AG etching process to scatter light. The AG etching process includes frosting and chemical etching polishing. This can be achieved with ordinary soda-lime glass or aluminosilicate glass. However, existing glass-ceramics often contain multiple crystalline phases (such as lithium disilicate, petalite, etc.) and residual glass phases, which exhibit vastly different tolerances to the etching solution. This variation leads to uneven etching rates, making it difficult to form a uniform and controllable microstructure across the entire surface. It also easily results in over-etched or under-etched areas, affecting the uniformity of haze and gloss, as well as optical performance.

[0007] In summary, existing technologies suffer from two major drawbacks: firstly, there is a lack of chemically strengthened glass solutions that can balance low cost with high drop resistance; secondly, existing high-performance microcrystalline glass is difficult to adapt to high-quality, uniform anti-glare surface treatment processes. These two issues together restrict the development of cover glass in a wider range of markets and applications. Summary of the Invention

[0008] To address the aforementioned issues, this application provides a high-alumina silicate microcrystalline glass containing a nano-nepheline phase for glare reduction. This glass achieves its glare reduction through controlled crystallization of a nano-scale nepheline reinforcing phase, possessing both an ultra-deep ion-exchange stress layer and excellent drop resistance. Furthermore, a short-time acid immersion process creates a spherical concave surface, thus achieving the glare reduction purpose.

[0009] The technical solution adopted in this application is as follows: In a first aspect, this application provides a high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare, the composition of which, by weight percentage, comprises: SiO2 47.0 ~ 62.0%, Al2O3 8.0 ~ 20.0%, Na2O 8.0 ~ 15.0%, K2O 3.5 ~ 10.0%, P2O5 4.5 ~ 14.0%, MgO 2.5 ~ 10.0%, ZrO2 0 ~ 1.5%; The weight ratio of Al2O3 to P2O5 is 0.5 to 4.4. The microcrystalline glass contains nepheline crystals with an average size of less than 100 nm, and this nepheline phase is the only crystalline phase. The microcrystalline glass has an anti-glare glass surface with a roughness of 0.05 ~ 0.4 μm.

[0010] Nepheline glass-ceramics is a high-performance functional material. Its core advantages are its extremely low coefficient of thermal expansion, excellent chemical stability, high strength, and good insulation, which makes it irreplaceable in fields such as high temperature resistance, thermal shock resistance, corrosion resistance, high strength, and insulation.

[0011] In the above scheme, P2O5 is added to high-alumina silicate glass. During the melting process, phase separation occurs, forming a phosphate phase and a silicate phase. During cooling, due to the differences between the phases, the phosphate phase is retained in the form of "droplets." During subsequent heat treatment, nepheline and other crystals preferentially precipitate at the phase boundaries. After the microcrystalline glass is immersed in acid for a certain period of time, the phosphate phase or nepheline crystals are preferentially etched away, leaving relatively uniform spherical pits on the surface, which reduces reflection and achieves an anti-glare effect.

[0012] Furthermore, the aforementioned microcrystalline glass with a thickness of 0.6 mm has a transmittance of over 90% at a wavelength of 550 nm.

[0013] Furthermore, the stress layer depth (DOL) of the aforementioned microcrystalline glass is greater than 50 μm, the surface compressive stress is greater than 750 MPa, and the drop height of the microcrystalline glass is greater than 0.7 m when subjected to a drop ball impact test with 180-grit sandpaper.

[0014] Furthermore, the aforementioned microcrystalline glass also includes a clarifying agent, the content of which is 0~1.0%.

[0015] Secondly, this application also provides a method for preparing the above-mentioned high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare, comprising: The above-mentioned ingredients are prepared, mixed, melted, and shaped. The resulting glass is then annealed at 550~700 ℃ to directly obtain a microcrystalline glass substrate with uniformly precipitated nano-nepheline crystal phase inside. The microcrystalline glass substrate was placed in a molten salt containing potassium ions and subjected to ion exchange treatment at 380~450 °C for 2~8 h. Chemically strengthened microcrystalline glass is immersed in an acid solution with a concentration of 1-30 wt% and soaked at 20-40 ℃ for 5-120 s to form uniformly distributed spherical pits on its surface, thereby obtaining an anti-glare glass surface.

[0016] Furthermore, the molten salt is KNO3 molten salt, and the ion exchange treatment temperature is 400~430 ℃, and the treatment time is 4~6 h.

[0017] Furthermore, the acid solution is at least one of hydrofluoric acid, nitric acid, sulfuric acid or hydrochloric acid, with a concentration of 5-20 wt%, and the soaking time is 15-60 s. Ultrasonic vibration is performed during the soaking process to ensure the uniformity of etching.

[0018] Furthermore, the haze of the aforementioned anti-glare glass surface is 3-50%.

[0019] Thirdly, this application also provides the use of the above-mentioned high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare as a transparent protective component, which is an electronic device cover or a transparent component for automobiles.

[0020] Furthermore, the aforementioned electronic device cover includes covers for mobile phones, tablets, laptops, or smartwatches; the automotive transparent components include windows, sunroofs, display covers, or optical sensor protective covers.

[0021] In summary, this application has the following beneficial effects: 1. This application introduces a specific proportion of P2O5 into a high-alumina silicate system and controls the Al2O3 / P2O5 weight ratio between 0.5 and 4.4, effectively inducing the directional precipitation of a single nepheline phase with an average size of less than 100 nm in the glass matrix. This unique nanocrystalline structure, combined with specific component design, enables the glass to achieve a surface compressive stress exceeding 750 MPa during subsequent chemical strengthening. More importantly, it significantly increases the stress layer depth (DOL) to over 50 μm. The direct result is a qualitative leap in the material's impact and drop resistance; for example, the drop height of a bare glass ball can exceed 0.7 m, fundamentally overcoming the deficiency of insufficient drop resistance caused by the shallow DOL (30-45 μm) in traditional high-alumina silicate glass.

[0022] 2. This application creatively utilizes the phase separation effect of P2O5 during the glass melting process and its promoting effect on the precipitation of nepheline phase, resulting in a specific microstructure (phosphate-related regions and nano-nepheline crystals) in the final glass-ceramic. In the acid etching step, the acid solution's faster selective etching rate compared to the residual glass phase in these regions allows for the formation of uniform, regular spherical pits on the surface. By adjusting parameters such as acid concentration, temperature, and time, the surface roughness can be precisely controlled between 0.05 and 0.4 μm, and the haze can be flexibly adjusted within the range of 3% to 50%, thus meeting the diverse needs for gloss, clarity, and anti-glare capabilities in various scenarios, from consumer electronics to automotive displays, achieving integrated functionality and performance.

[0023] 3. Thanks to the uniform precipitation and precise composition control of nanoscale nepheline phase (<100 nm), this invention successfully achieves an excellent combination of optical performance, mechanical strength, and functionalized surface. Specifically, the microcrystalline glass maintains a transmittance of over 90% at a wavelength of 550 nm with a thickness of 0.6 mm, ensuring excellent optical clarity. Simultaneously, its Vickers hardness is greater than 700 HV, achieving both deep stress (DOL≥50 μm) and high surface compressive stress (CS≥750 MPa) while also possessing good scratch resistance. Particularly noteworthy is the uniform anti-glare surface with controllable roughness (0.05~0.4 μm) achieved through the aforementioned unique acid etching process, without sacrificing the material's intrinsic strength and light transmittance. This comprehensive combination of high light transmittance, high hardness, high strength, high impact resistance, and inherently high-quality anti-glare function makes the material of this invention an ideal "all-around" cover solution. Attached Figure Description

[0024] Figure 1 The XRD pattern of the glass-ceramic provided in Embodiment 1 of this application; Figure 2 This is a transmittance diagram of the microcrystalline glass provided in Embodiment 1 of this application. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Specific conditions not specified in the examples shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0026] The performance testing method for this application is as follows: (1) Determination of stress layer depth (DOL) and surface stress (CS): The surface stress meter (model: FSM-6000L) was used for measurement.

[0027] (2) Transmittance measurement: Using a UV-Vis-NIR spectrophotometer, the transmittance of a 0.6 mm thick sample was measured at a wavelength of 550 nm and the transmittance value was recorded.

[0028] (3) Drop resistance test (sandpaper drop method): The sample was fixed on a simulated mobile phone model, with a total mass of 186 g. Under standard environmental conditions, it was dropped onto a test surface covered with 180-grit sandpaper. The test base height was 30 cm, and the drop height was increased by 5 cm each time, with one drop at each height until the sample broke. The lowest drop height that caused the sample to break was recorded. This test was repeated at least five times, and the final result was the average of the valid data.

[0029] (4) Vickers hardness test: The test was performed using an automatic micro Vickers hardness tester according to the standard micro Vickers hardness test method.

[0030] (5) Surface roughness measurement: Use a contact or non-contact surface roughness measuring instrument to measure the arithmetic mean roughness (Ra value) of the anti-glare surface of the sample.

[0031] (6) Haze measurement: The haze is measured using an integrating sphere haze meter according to the standard haze test method.

[0032] (7) Structural characterization: X-ray diffraction (XRD) was used to confirm the crystal phase composition, and scanning electron microscopy (SEM) or transmission electron microscopy (TEM) was used to observe the morphology and size distribution of nepheline crystals.

[0033] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention. Example

[0034] This set of embodiments provides a high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare properties, which is prepared through the following steps: (1) Prepare the ingredients according to the component content in Table 1, pour the mixed raw materials into a platinum crucible, and melt them in a high-temperature furnace.

[0035] (2) Pour the molten glass into a metal mold, place the glass in an annealing furnace for precision annealing and cooling. The annealing temperature is 600 ℃, and the holding time at this temperature is 120 min. Then, let it cool naturally to 100 ℃. After cooling, slice and polish the glass block to obtain a transparent sample with dimensions of 155×73×0.6 mm. (3) Insert some glass samples into the tempering frame and then place them in a preheating furnace for preheating. The preheating temperature starts from room temperature and rises to 380 ℃ within 30 min. After holding at this temperature for 30 min, the samples are placed in molten pure KNO3 at 420 ℃ for chemical strengthening for 5 h. After strengthening, the samples are transferred to a preheating furnace at 380 ℃. The heating power of the preheating furnace is turned off, and the samples are allowed to cool naturally in the furnace to below 100 ℃ before being removed. After the samples have cooled to room temperature, they are cleaned and dried. The transmittance is measured and recorded in Table 2.

[0036] (4) After preparation, the sample was immersed in a 5% HF acid bath for 60 s for etching, cleaned, and dried. After preparing the anti-glare surface, the performance of the samples prepared in each example was tested, and the results are shown in Table 2 and... Figure 1 , Figure 2 As shown.

[0037] Table 1. Ingredient composition of the examples and comparative examples

[0038] Table 2. Performance test results of the examples and comparative examples

[0039] From the test data of Example 1 ( Figure 1-2 The performance comparison of all examples and comparative examples (Table 2) shows that: (1) XRD analysis shows that the diffraction pattern of Example 1 matches the standard nepheline pattern and has no impurity peaks, confirming that its crystal phase is a single nepheline phase. Combined with the electron microscopy observation of all examples, the grain size is less than 100 nm. This directly verifies that the core design of controlling the Al2O3 / P2O5 weight ratio at 0.5~4.4 can successfully induce the directional precipitation of the target nanocrystalline phase in the glass matrix. The results of the comparative examples demonstrate the necessity of this requirement from the opposite perspective. Comparative Example 1 (insufficient P2O5) and Comparative Example 4 (no P2O5) cannot effectively precipitate, and their performance drops back to the level of ordinary glass; Comparative Example 3 (Al / P ratio too low) suffers from performance degradation due to uncontrolled crystallization. This set of comparisons proves that without the component control of the present invention, it is impossible to obtain the required uniform nanostructure.

[0040] (2) The chemical strengthening properties of all embodiments far exceed those of the comparative examples and traditional high-alumina-silicon glasses. Their stress layer depth (DOL) is greater than 55 μm, surface compressive stress (CS) is higher than 775 MPa, and sandpaper drop height is greater than 0.7 m. This confirms that the presence of the nano-nepheline phase greatly improves ion exchange efficiency and material toughness. Meanwhile, the transmittance curve of Example 1 shows that its transmittance in the visible light region (550 nm) is as high as 91.2%. The transmittance of all embodiments is above 90.7%, proving that nanocrystallization does not sacrifice optical performance.

[0041] (3) After acid etching, the surface roughness (Ra) of all embodiments remained stable within the effective anti-glare range of 0.05-0.4 μm, and the haze was adjustable. This indicates that the phase-separated structure and nano-nepheline phase introduced by P2O5 achieve uniform and controllable selective etching, overcoming the problem that traditional microcrystalline glass is difficult to obtain a uniform anti-glare surface.

[0042] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A high-alumina silicate microcrystalline glass containing nano-nepheline phase and possessing anti-glare properties, characterized in that, Its composition, by weight percentage, includes: SiO2 47.0 ~ 62.0%, Al2O3 8.0 ~ 20.0%, Na2O 8.0 ~ 15.0%, K2O 3.5 ~ 10.0%, P2O5 4.5 ~ 14.0%, MgO 2.5 ~ 10.0%, ZrO2 0 ~ 1.5%; The weight ratio of Al2O3 to P2O5 is 0.5 to 4.

4. The microcrystalline glass contains nepheline crystals with an average size of less than 100 nm, and this nepheline phase is the only crystalline phase. The microcrystalline glass has an anti-glare glass surface with a roughness of 0.05 ~ 0.4 μm.

2. The high-alumina silicate microcrystalline glass containing nano-nepheline phase and with anti-glare properties according to claim 1, characterized in that, The microcrystalline glass with a thickness of 0.6 mm has a transmittance of over 90% at a wavelength of 550 nm.

3. The high-alumina silicate microcrystalline glass containing nano-nepheline phase and with anti-glare properties according to claim 1, characterized in that, The microcrystalline glass has a stress layer depth (DOL) greater than 50 μm and a surface compressive stress greater than 750 MPa. When the microcrystalline glass is subjected to a drop ball impact test with 180-grit sandpaper, its drop height is greater than 0.7 m.

4. The high-alumina silicate microcrystalline glass containing nano-nepheline phase and with anti-glare properties according to claim 1, characterized in that, The microcrystalline glass also includes a clarifying agent, the content of which is 0~1.0%.

5. A method for preparing a high-alumina silicate microcrystalline glass containing nano-nepheline phase and with anti-glare properties as described in any one of claims 1-4, characterized in that, It includes: According to claim 1, the ingredients are prepared, mixed, melted, and shaped, and then the resulting glass is annealed at 550~700 °C to directly obtain a microcrystalline glass substrate with uniformly precipitated nano-nepheline crystal phase inside. The microcrystalline glass substrate is immersed in an acid solution with a concentration of 1~30 wt% and soaked at 20~40 ℃ for 5~120 s to form uniformly distributed spherical pits on its surface to obtain an anti-glare glass surface. The anti-glare glass was placed in molten salt containing potassium ions and subjected to ion exchange treatment at 380~450 °C for 2~8 h.

6. The method for preparing high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare according to claim 5, characterized in that, The molten salt is KNO3 molten salt, and the ion exchange treatment temperature is 400~430 ℃, and the treatment time is 4~6 h.

7. The method for preparing high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare according to claim 5, characterized in that, The acid solution is at least one of hydrofluoric acid, nitric acid, sulfuric acid or hydrochloric acid, with a concentration of 5-20 wt%, and the soaking time is 15-60 s. Ultrasonic vibration is performed during the soaking process to ensure the uniformity of etching.

8. The method for preparing high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare according to claim 5, characterized in that, The haze on the surface of the anti-glare glass is 3-50%.

9. The use of a high-alumina silicate microcrystalline glass containing nano-nepheline phase and anti-glare as described in any one of claims 1-4 as a transparent protective component, characterized in that, The transparent protective component is an electronic device cover or a transparent component used in automobiles.

10. The use according to claim 9, characterized in that, The electronic device cover includes the cover of a mobile phone, tablet computer, laptop computer, or smartwatch; the automotive transparent component includes a window, sunroof, display cover, or optical sensor protective cover.

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