Ultra-thin glass suitable for being produced by means of down-drawing method, and preparation method therefor

Abstract

Ultra-thin glass suitable for being produced by means of a down-drawing method, and a preparation method therefor. The ultra-thin glass is prepared from the following raw materials in percentages by mass: 58-68% of SiO2, 8-15% of Al2O3, 1-6% of MgO, 10-15% of Na2O, 2-5% of K2O, 1-5% of CaO, 0.1-0.8% of ZrO2, 0.1-0.8% of TiO2, 0.1-0.8% of La2O3, 0.1-0.8% of Y2O3 and 0.5-3.5% of Li2O. The glass prepared by means of the method belongs to aluminosilicate glass, such that the strength and toughness of the obtained ultra-thin glass are higher than those of common silicate glass. By adding alkali metals and alkaline earth metals in different proportions, the prepared glass has high flexibility, high stability and excellent performance; the melting temperature and the forming temperature of preparation are relatively low; and the glass has an important application value in the technical field of ultra-thin glass.

Description

Flexible glass suitable for down-draw production and preparation method thereof

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on January 12, 2024, with application number CN202410048137.8 and invention name “A flexible glass suitable for down-draw production and its preparation method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of glass preparation technology, and specifically relates to a flexible glass suitable for down-draw production and a preparation method thereof. Background Art

[0003] The development of smart electronic products such as foldable smartphones and bendable wearables, as well as curved display technology, has placed higher demands on flexible displays. Flexible glass (UTG) refers to ultra-thin glass with a thickness of ≤0.1mm. It is the core material for foldable display devices and features ultra-thinness, wear resistance, high strength, and bendability, making it an important new development direction for flexible foldable cover panels. Flexible glass production methods can be divided into primary forming and secondary processing methods. The secondary processing method of "glass sheet + chemical thinning" suffers from low product yield, small size, raw material waste, and acid exposure. The primary primary forming process is the down-draw method, which includes slit down-draw, overflow down-draw, and waterfall down-draw. The down-draw method is simple, produces high-quality flexible glass, and enables continuous production of glass ribbons with high yield and environmental friendliness. It also facilitates the production of larger and stronger flexible glass, better meeting market demand for flexible glass. However, the down-draw method currently presents numerous challenges, including high melting temperatures, difficult raw material melting, high viscosity, and difficulty in drawing thin sheets. Because flexible glass needs to meet the requirements of both strength and toughness, but current glass materials cannot achieve both high strength and high toughness at the same time, it is necessary to study the relationship between glass components to balance toughness and strength to meet the application of flexible products. Therefore, research on flexible glass suitable for down-draw production has important value in the field of glass manufacturing. Summary of the Invention

[0004] The purpose of this application is to overcome the defects of the prior art and provide a flexible glass suitable for down-draw production and a preparation method thereof.

[0005] The purpose of this application can be achieved through the following technical solutions:

[0006] A first aspect of the present application provides a flexible glass suitable for down-draw production, which is made of the following raw materials in the following mass percentages:

[0007] 58-68% SiO2, 8-15% Al2O3, 1-6% MgO, 10-15% Na2O, 2-5% K2O, 1-5% CaO, 0.1-0.8% ZrO2, 0.1-0.8% TiO2, 0.1-0.8% La2O3, 0.1-0.8% Y2O3, 0.5-3.5% Li2O.

[0008] In some embodiments of the present application, a mass ratio of raw materials for flexible glass produced by a down-draw method satisfies the following conditions:

[0009] 15%≤Na2O+K2O+Li2O≤20%, and 2≤Na2O:K2O≤5;

[0010] 1≤Al2O3: (CaO+MgO+La2O3+Y2O3)≤2;

[0011] 0.5%≤ZrO2+TiO2≤1%; 0.5%≤La2O3+Y2O3≤1%.

[0012] A second aspect of the present application provides a method for preparing flexible glass suitable for down-draw production, comprising the following steps:

[0013] S1. Mix the raw materials evenly and add them into a platinum crucible for melting;

[0014] S2. Cast the molten glass into a copper mold, place the cast glass into an annealing furnace for annealing, cool it to room temperature with the furnace, and take it out to obtain flexible glass suitable for down-draw production.

[0015] In some embodiments of the present application, the melting temperature in step S1 is 1580° C.-1650° C., and the holding time is 3 hours.

[0016] In some embodiments of the present application, the annealing temperature in step S2 is 580° C.-680° C., and the holding time is 1 hour.

[0017] Beneficial effects of this application:

[0018] 1. The glass produced in this application is aluminosilicate glass, and the strength and toughness of the obtained flexible glass are higher than those of ordinary silicate glass;

[0019] 2. The addition of CaO and control of its content in this application can reduce the viscosity of the glass, promote glass melting and clarification, and increase the chemical stability and flexibility of the glass;

[0020] 3. The addition of Y2O3 in this application can effectively reduce the melting and clarification temperature of the glass and the forming and thinning temperature, while increasing the elastic modulus of the glass and thus enhancing the flexibility of the glass;

[0021] 4. The addition of MgO in this application can not only reduce the high-temperature viscosity of the glass, but also improve the crystallization performance of the glass;

[0022] 5. This application adds ZrO2 and TiO2 to improve the strength of the glass, and at the same time, the glass structure can be optimized and the performance can be improved during the annealing process;

[0023] 6. The addition of Li2O in this application can significantly reduce the melting temperature of the glass and, under certain conditions, improve the internal structure of the glass and enhance its performance, but it will also increase the tendency of the glass to crystallize;

[0024] 7. La2O3 added in this application is an important rare earth oxide, which can lower the melting temperature and molding temperature of glass, reduce the generation of tiny bubbles, and enhance the strength of glass. Not only that, it can also reduce the surface tension of glass.

[0025] Therefore, the glass produced in this application has high flexibility, strong stability, good clarification effect, and excellent performance. The melting temperature and molding temperature are low, and the viscosity is low. It is suitable for down-draw production and has important application value in the field of flexible glass technology. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] Example 1

[0028] Weigh the batch materials according to the following mass percentages:

[0029] 58% SiO2, 13% Al2O3, 4.2% MgO, 14% Na2O, 3% K2O, 5% CaO, 0.4% ZrO2, 0.1% TiO2, 0.6% La2O3, 0.2% Y2O3, 1.5% Li2O. The raw materials in this embodiment are Li2O, Na2O, and K2O. In actual use, the raw materials are Li2CO3, Na2CO3, and K2CO3.

[0030] S1. Mix the raw materials evenly and add them into a platinum crucible for melting at a melting temperature of 1610°C for 3 hours;

[0031] S2. The molten glass is cast into a copper mold and then placed in an annealing furnace for annealing at 580°C for 1 hour. After annealing, the glass is cooled to room temperature and removed from the furnace to obtain flexible glass suitable for down-draw production.

[0032] Example 2

[0033] Weigh the batch materials according to the following mass percentages:

[0034] 64% SiO2, 12% Al2O3, 2.5% MgO, 12% Na2O, 2.5% K2O, 3.3% CaO, 0.2% ZrO2, 0.6% TiO2, 0.4% La2O3, 0.5% Y2O3, 2% Li2O. The raw materials in this embodiment are Li2O, Na2O, and K2O. In actual application, the raw materials are Li2CO3, Na2CO3, and K2CO3.

[0035] S1. Mix the raw materials evenly and add them into a platinum crucible for melting at a melting temperature of 1610°C for 3 hours;

[0036] S2. The molten glass is cast into a copper mold and then placed in an annealing furnace for annealing at 630°C for 1 hour. After annealing, the glass is cooled to room temperature and removed from the furnace to obtain flexible glass suitable for down-draw production.

[0037] Example 3

[0038] Weigh the batch materials according to the following mass percentages:

[0039] 67% SiO2, 8% Al2O3, 3.5% MgO, 10% Na2O, 5% K2O, 1.5% CaO, 0.5% ZrO2, 0.5% TiO2, 0.7% La2O3, 0.3% Y2O3, 3% Li2O. The raw materials in this embodiment are Li2O, Na2O, and K2O. In actual use, the raw materials are Li2CO3, Na2CO3, and K2CO3.

[0040] S1. Mix the raw materials evenly and add them into a platinum crucible for melting at a melting temperature of 1600°C for 3 hours;

[0041] S2. The molten glass is cast into a copper mold and then placed in an annealing furnace for annealing at 680°C for 1 hour. After annealing, the glass is cooled to room temperature and taken out of the furnace to obtain flexible glass suitable for down-draw production.

[0042] Comparative Example 1

[0043] Weigh the batch materials according to the following mass percentages:

[0044] 63% SiO2, 15% Al2O3, 2.7% MgO, 11% Na2O, 4% K2O, 2% CaO, 0.7% ZrO2, 0.4% TiO2, 0.1% La2O3, 0.1% Y2O3, 1% Li2O. The raw materials in this embodiment are Li2O, Na2O, and K2O. In actual use, the raw materials are Li2CO3, Na2CO3, and K2CO3.

[0045] S1. Mix the raw materials evenly and add them into a platinum crucible for melting at a melting temperature of 1620°C for 3 hours;

[0046] S2. The molten glass is cast into a copper mold and then placed in an annealing furnace for annealing at 650°C for 1 hour. After annealing, the glass is cooled to room temperature and removed from the furnace to obtain flexible glass suitable for down-draw production.

[0047] Comparative Example 2

[0048] Weigh the batch materials according to the following mass percentages:

[0049] 67% SiO2, 12% Al2O3, 2.5% MgO, 12% Na2O, 2.5% K2O, 4% CaO. In this embodiment, the raw materials are Na2O and K2O. In actual production, the raw materials are Na2CO3 and K2CO3.

[0050] S1. Mix the raw materials evenly and add them into a platinum crucible for melting at a melting temperature of 1630°C for 3 hours;

[0051] S2. The molten glass is cast into a copper mold and then placed in an annealing furnace for annealing at 680°C for 1 hour. After annealing, the glass is cooled to room temperature and taken out of the furnace to obtain flexible glass suitable for down-draw production.

[0052] Comparative Example 3

[0053] Weigh the batch materials according to the following mass percentages:

[0054] 67% SiO2, 12% Al2O3, 2.5% MgO, 12% Na2O, 2.5% K2O, 3.8% CaO, 0.2% ZrO2. In this embodiment, the raw materials are Na2O and K2O. In actual production, the raw materials are Na2CO3 and K2CO3.

[0055] S1. Mix the raw materials evenly and add them into a platinum crucible for melting at a melting temperature of 1640°C for 3 hours;

[0056] S2. The molten glass is cast into a copper mold and then placed in an annealing furnace for annealing at 650°C for 1 hour. After annealing, the glass is cooled to room temperature and removed from the furnace to obtain flexible glass suitable for down-draw production.

[0057] The glasses obtained from Examples 1-3 and Comparative Examples 1-3 were subjected to the following performance tests according to different test standards:

[0058] The surface tension is measured using the national standard GB / T 39797-2021 "Surface tension of glass melts - Test method - Sessile drop method";

[0059] The elastic modulus is measured using the national standard GB / T 37788-2019 "Test method for elastic modulus of ultra-thin glass";

[0060] The fracture toughness was determined using the national standard GB / T 37900-2019 “Test method for hardness and fracture toughness of ultra-thin glass - Small load Vickers hardness indentation method”.

[0061] The glass composition and the measured results are shown in Table 1 below:

[0062] Table 1 Note: “ / ” means not added.

[0063] It can be seen from Table 1 above that the weight percentage of each raw material of the flexible glass of Examples 1-3 of the present application is controlled within the scope of the present application. The prepared glass has high flexibility, strong stability, excellent performance, and a low molding temperature. It is suitable for down-draw production and has important application value in the field of flexible glass technology. However, the weight percentage of the raw materials of Comparative Examples 1-3 is not controlled within the scope of the present application, resulting in a higher molding temperature of the prepared flexible glass and a decrease in fracture toughness and elastic modulus.

[0064] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0065] The above content is merely an example and explanation of the present application. Technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present application.

Claims

1. A flexible glass suitable for production by the down-draw method, characterized in that, It is made from raw materials with the following mass percentages: 58 - 68% of SiO2, 8 - 15% of Al2O3, 1 - 6% of MgO, 10 - 15% of Na2O, 2 - 5% of K2O, 1 - 5% of CaO, 0.1 - 0.8% of ZrO2, 0.1 - 0.8% of TiO2, 0.1 - 0.8% of La2O3, 0.1 - 0.8% of Y2O3, 0.5 - 3.5% of Li2O.

2. The flexible glass suitable for the drawing method according to claim 1, characterized in that, The mass ratio between the raw materials meets the following conditions: 15% ≤ Na2O + K2O + Li2O ≤ 20%, and 2 ≤ Na2O:K2O ≤ 5; 1 ≤ Al2O3:(CaO + MgO + La2O3 + Y2O3) ≤ 2; 0.5% ≤ ZrO2 + TiO2 ≤ 1%; 0.5% ≤ La2O3 + Y2O3 ≤ 1%.

3. A preparation method of the flexible glass suitable for the down-draw method production according to any one of claims 1-2, characterized in that, It includes the following steps: S1. Mix the raw materials evenly and melt them in a platinum crucible. S2. Pour the melted glass into a copper mold. After pouring, put the glass into an annealing furnace for annealing. After annealing, cool it to room temperature with the furnace. After taking it out, flexible glass suitable for the down-draw method production is obtained.

4. The preparation method of the flexible glass suitable for the down-draw method production according to claim 3, characterized in that In step S1, the melting temperature is 1580°C - 1650°C, and the heat preservation time is 3 h.

5. The preparation method of the flexible glass suitable for the down-draw method production according to claim 3, characterized in that, In step S2, the annealing temperature is 580°C - 680°C, and the heat preservation time is 1 h.

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