The present disclosure belongs to the field of glass manufacturing, and in particular relates to a microcrystalline glass, a manufacturing method therefor and a use thereof.
As the information age approaches, the portability and ease of operation of smart devices become particularly important, thereby making mobile phones the most promising smart terminal device today. More and more new materials are used in the design and production for smartphones, and the cover glass always participates therein. The cover glass of mobile phone, which enters a new 3D era through the 2.5D era from 2D, not only makes the appearance of mobile phones more exquisite, but also greatly enhances the sense of touch experience for the user groups of mobile phone.
Glass becomes the best choice for screen cover because of its excellent mechanical properties and excellent light transmission performance. However, people are no longer satisfied with the traditional cover made of glass, and thus the microcrystalline glass emerges as the new development direction of cover glass. New materials bring not only new experiences, but also new challenges.
For cover glass with specific shapes (such as with curved edges), secondary heating crystallization is often required, and during the molding process of secondary crystallization, microcrystalline glass is prone to irregular deformation, resulting in lower yields and material waste.
How to control the deformation quantity of microcrystalline glass manufactured by the secondary crystallization technology is a pressing technical problem to be solved in this field.
With regard to the deficiencies of the prior art, the first objective of the present disclosure is to provide a method for manufacturing microcrystalline glass, wherein the method comprises the steps of:
−a×t+652≤x1≤−a×t+667, {circle around (1)}
y
1=0.0029x1+b, {circle around (2)}
The present disclosure controls the temperature and duration of the primary crystallization for the raw glass sheet that needs to be subjected to secondary crystallization, so as to obtain the desired types of crystal phase and crystal growth rate. Therefore, the density y1 after primary crystallization meets 2.440 g/cm3≤y1≤2.490 g/cm3, which closes to the density after secondary crystallization, such that the deformation rate caused by secondary crystallization is reduced and product yield is improved.
The presumed principle is that when the glass reaches the corresponding density after primary crystallization, the crystal growth inside the glass goes into a hysteresis phase with a relatively slow rate, which has a macroscopic manifestation that the glass does not expand significantly. If the density after primary crystallization is less than 2.440 g/cm3, the various crystalline phases in the glass have not been fully grown and transformed, and then after secondary crystallization, it will lead to an excessive deformation rate of the microcrystalline glass. If the density after primary crystallization is greater than 2.490 g/cm3, the crystalline phases in the glass have grown and transformed completely, and then after the secondary crystallization, it will lead to excessive growth of the crystalline phases. In this case, the deformation rate of the glass will be reduced, but the optical properties such as transmittance of the glass will be deteriorated.
It is understood that the raw glass sheets can be obtained from raw glass materials after melting, molding, and cold processing, wherein the specific preparation process typically, but not limiting, comprises weighing and mixing of the glass raw materials; melting and forming of the glass, wherein forming methods comprise but are not limited to float glass process, overflow, recycle flattening, and pouring, etc.; and annealing of the formed glass slabs and then performing cold processing to obtain the raw glass sheets of the same size.
As a preferred technical solution, the primary crystallization duration t is of 10-300 min (e.g. 25 min, 40 min, 55 min, 70 min, 95 min, 110 min, 135 min, 155 min, 195 min, 210 min, 240 min, 270 min, or 290 min, etc.), preferably 50-200 min, preferably 80-150 min, and preferably 90-120 min; the density of the glass after the primary crystallization meets 2.447 g/cm3≤y1≤2.455 g/cm3, preferably 2.455 g/cm3≤y1≤2.460 g/cm3, preferably 2.460 g/cm3≤y1≤2.481 g/cm3, and preferably 2.481 g/cm3≤y1≤2.490 g/cm3.
The glass density after primary crystallization meets 2.440 g/cm3≤y1≤2.455 g/cm3 to further achieve the effect of controlling the deformation rate of glass after secondary crystallization at 1.2%˜1.8%; the glass density after primary crystallization meets 2.455 g/cm3≤y1≤2.460 g/cm3 to further achieve the effect of controlling the deformation rate of glass after secondary crystallization at 1.0%˜1.2%; the glass density after primary crystallization meets 2.460 g/cm3≤y1≤2.481 g/cm3 to further achieve the effect of controlling the deformation rate of glass after secondary crystallization at 0%˜1.0%; and the glass density after primary crystallization meets 2.481 g/cm3≤y1≤2.490 g/cm3 to further achieve the effect of controlling the deformation rate of glass after secondary crystallization at 0.0%˜0.5%.
As a preferred technical solution, the nucleation temperature is of 520-580° C. (e.g., 525° C., 530° C., 535° C., 540° C., 545° C., 550° C., 560° C., 565° C., 570° C., or 575° C., etc.), preferably 545-575° C., preferably 550-570° C.; preferably, the nucleation duration is of 180-360 min (e.g., 190 min, 195 min, 205 min, 225 min, 240 min, 245 min, 260 min, 280 min, 300 min, 310 min, 320 min, or 330 min, etc.), preferably 200-280 min, preferably 220-250 min.
A suitable nucleation temperature can achieve an effect of uniform nucleation.
As a preferred technical solution, the process of secondary crystallization comprises, in sequence, a heating stage, a thermoforming stage, and a cooling stage.
The process of the secondary crystallization is staged to control the temperature of each stage precisely, thereby reducing or even eliminating the impact on material properties due to the instability of processing equipment and further improving the consistency of the finished product to enhance production yield.
As a preferred technical solution, the heating stage is to raise the temperature from room temperature at a rate of 10-60° C./min to a first target temperature; preferably the heating rate is of 20-50° C./min, preferably 30-40° C./min; and the first target temperature is of 650-750° C., and preferably the first target temperature is of 670-730° C., preferably 680-710° C.
As a preferred technical solution, the thermoforming stage is to raise the temperature from the first target temperature to a second target temperature; and the heating rate is 15-50° C./min, preferably 20-40° C./min, and preferably 30-40° C./min.
The second target temperature is of 680-800° C., preferably 700-780° C., preferably 720-750° C., and preferably 730-740° C.
As a preferred technical solution, the cooling stage is to cool down from the second target temperature to room temperature at a rate of 30-50° C./min, preferably at a cooling rate of 35-45° C./min, and preferably 38-40° C./min.
A suitable temperature change curve can reduce the impact of processing equipment on the glass, on the one hand, to prevent the glass from breaking due to sudden cold and sudden heat, and on the other hand, to prevent the increased working hours and low production efficiency due to a too slow heating or cooling rate. In addition, by controlling the temperature change curve, the optical properties of the glass can also be improved.
As a preferred technical solution, the raw glass sheet is lithium-aluminum-silicon glass.
Preferably, the raw glass sheet contains, in mol %, the following components:
3~7
10~25
As a preferred technical solution, the Al2O3 content in the raw glass sheet is of 4-6 mol %, preferably 4.5-5.5 mol %.
As a preferred technical solution, the ZrO2 content in the raw glass sheet is of 1-4 mol %, preferably 2.5-3.5 mol %.
As a preferred technical solution, the Li2O content in the raw glass sheet is of 14-20 mol %, preferably 16-19 mol %, and preferably 17-18 mol %.
As a preferred technical solution, the Na2O content in the raw glass sheet is of 0.7-3.2 mol %, preferably 1.0-2.5 mol %.
As a preferred technical solution, the P2O5 content in the raw glass sheet is of 0.8-1.5 mol %, preferably 1-1.3 mol %.
As a preferred technical solution, the B2O3 content in the raw glass sheet is of 0.5-1.5 mol %, preferably 0.8-1.2 mol %.
As a preferred technical solution, the SiO2 content in the raw glass sheet is of 67-71 mol %, preferably 68-70 mol %.
The second objective of the present disclosure is to provide a microcrystalline glass obtained by a method as described in the first objective.
The third objective of the present disclosure is to provide a use of microcrystalline glass manufactured by the method as described in the first objective, wherein the microcrystalline glass is used as any one of a mobile phone cover, a watch cover, a tablet computer cover, or an automobile display cover.
Compared with the prior art, the present disclosure has at least the following beneficial effects.
The present disclosure controls the temperature and duration of the primary crystallization of the raw glass sheet that needs to be subjected to the secondary crystallization, such that the density y1 after primary crystallization meets 2.440 g/cm3≤y1≤2.490 g/cm3, which closes to the density after secondary crystallization, and thus the deformation degree during secondary crystallization is reduced. Moreover, the manufactured glass has a good transmittance, thereby improving product yield.
The FIGURE is a schematic view of the measured position when measuring the change in glass size after secondary crystallization.
The technical solutions of the present disclosure are further described below by means of specific embodiments.
It should be apparent to those skilled in the art that the embodiments are merely helpful in understanding the present disclosure and should not be considered as a specific limitation to the present disclosure.
A microcrystalline glass was manufactured by the following method.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 640° C. and the primary crystallization duration was 100 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 635° C. and the primary crystallization duration was 100 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 650° C. and the primary crystallization duration was 100 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 637° C. and the primary crystallization duration was 90 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 642° C. and the primary crystallization duration was 90 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 647° C. and the primary crystallization duration was 90 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 652° C. and the primary crystallization duration was 90 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 635° C. and the primary crystallization duration was 120 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 640° C. and the primary crystallization duration was 120 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 655° C. and the primary crystallization duration was 100 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 636° C. and the primary crystallization duration was 300 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 650° C. and the primary crystallization duration was 10 min.
The difference from Example 1 was that the glass formulation of step (1) was as follows, wherein
The difference from Example 1 was that the glass formulation of step (1) was as follows, wherein
The difference from Example 1 was that the nucleation temperature of step (3) was 520° C. and the nucleation duration was 360 min; and
The difference from Example 1 was that the nucleation temperature of step (3) was 580° C. and the nucleation duration was 180 min; and
The difference from Example 1 was that the primary crystallization temperature of step (3) was 630° C. and the primary crystallization duration was 150 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 675° C. and the primary crystallization duration was 100 min.
The difference from Example 1 was that the primary crystallization temperature of step (3) was 635° C. and the primary crystallization duration was 50 min.
Performance Test
The relevant parameters and test results of primary crystallization are shown in Table 1.
According to Table 1, it can be seen that
In the Comparative Example 1, the temperature and duration of primary crystallization meet the condition I, but the temperature and density after primary crystallization do not meet the condition II. It can be seen that, after secondary crystallization, the deformation rate of the glass increases to 1.88% and the light transmittance is poorer.
In the Comparative Example 2, the temperature and duration of primary crystallization do not meet conditions I and II, where the density after primary crystallization exceeds 2.490 g/cm3. It can be seen that the light transmittance is deteriorated, although a relatively small deformation rate can be obtained.
In the Comparative Example 3, the temperature and duration of primary crystallization do not satisfy conditions I and II. It can be seen that after the secondary crystallization, the deformation rate of the glass increases to 1.53% and the light transmittance is poorer.
The above-described embodiments are only a part of the embodiments of the present disclosure, and not all of them. The detailed description of embodiments of the present disclosure is not intended to limit the scope of the present disclosure for which protection is claimed, but merely denote selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative effort shall fall within the protection scope of the present disclosure.
Number | Date | Country | Kind |
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202110866102.1 | Jul 2021 | CN | national |
This application is a continuation-in-part application of International Application No. PCT/CN2022/109031, filed on Jul. 29, 2022, which is based upon and claims priority to Chinese Patent Application No. 202110866102.1, filed on Jul. 29, 2021, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2022/109031 | Jul 2022 | US |
Child | 18423343 | US |