A flexible glass suitable for down-draw production and its preparation method

Abstract

The invention discloses a flexible glass suitable for down-drawing production and a preparation method thereof, belonging to the technical field of glass preparation. The glass is made of the following raw materials in mass percentage: 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. The prepared glass belongs to aluminosilicate glass, which ensures that the strength and toughness of the obtained flexible glass are higher than those of general silicate glass; adding alkali metals and alkaline earth metals in different proportions makes the prepared glass have high flexibility, strong stability and excellent performance, and the melting temperature and molding temperature of the prepared glass are low, which has important application value in the technical field of flexible glass.

Description

Technical Field

[0001] The invention belongs to the technical field of glass preparation, and in particular relates to a flexible glass suitable for down-draw production and a preparation method thereof. Background Art

[0002] The development of smart electronic products and curved display technology such as foldable smartphones and bendable electronic wearable devices has put forward higher requirements for flexible displays. Flexible glass (UTG) refers to ultra-thin glass with a thickness of ≤0.1mm. It is the core material of foldable display devices. It has the characteristics of ultra-thin, wear-resistant, high strength, and bendability. It is an important new development direction for flexible folding cover plates. The production methods of flexible glass can be divided into one-time forming method and secondary processing method. Among them, the secondary processing process of "glass original sheet + chemical thinning" has problems such as low product yield, small size, waste of raw materials, and acid involvement. The one-time forming process is mainly the down-pull method, including slit down-pull, overflow down-pull and waterfall down-pull. The down-pull method has a simple process, the surface quality of the produced flexible glass is high, and the continuous production of glass strips can be realized. It has a high yield rate and strong environmental protection. It is easy to produce flexible glass with larger format size and higher strength, which is more in line with the market demand for flexible glass. However, there are many problems in the production process of the down-pull method, such as high melting temperature, difficult melting of raw materials, high viscosity, and difficulty in thinning. Because flexible glass needs to meet the requirements of strength and toughness at the same time, but current glass materials cannot have 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, studying flexible glass suitable for down-draw production has important value in the field of glass manufacturing. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide a flexible glass suitable for down-draw production and a preparation method thereof.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A flexible glass suitable for down-draw production, made from the following raw materials in percentage by mass:

[0006] 58-68% SiO 2 8-15% Al 2 O 3 , 1-6% MgO, 10-15% Na 2 O, 2-5% K 2 O, 1-5% CaO, 0.1-0.8% ZrO 2 , 0.1-0.8% TiO 2 , 0.1-0.8% La 2 O 3, 0.1-0.8% Y 2 O 3 0.5-3.5% Li 2 O.

[0007] Furthermore, a flexible glass suitable for down-draw production has a mass ratio of raw materials that meets the following conditions:

[0008] 15%≤Na 2 O+K 2 O+Li 2 O≤20%, and 2≤Na 2 O:K 2 O≤5;

[0009] 1≤Al 2 O 3 :(CaO+MgO+La 2 O 3 +Y 2 O 3 )≤2;

[0010] 0.5%≤ZrO 2 +TiO 2 ≤1%;0.5%≤La 2 O 3 +Y 2 O 3 ≤1%.

[0011] A method for preparing flexible glass suitable for down-draw production comprises the following steps:

[0012] S1. Mix the raw materials evenly and add them into a platinum crucible for melting;

[0013] S2. Cast the molten glass into a copper mold, put the casted glass into an annealing furnace, and control the annealing curve during annealing. After the annealing is completed, cool it to room temperature with the furnace, and take it out to obtain a flexible glass suitable for down-draw production.

[0014] Furthermore, in step S1, the melting temperature is 1580°C-1650°C, and the holding time is 3 hours.

[0015] Furthermore, in step S2, the annealing temperature is 580° C.-680° C., and the holding time is 1 hour.

[0016] Beneficial effects of the present invention:

[0017] 1. The glass obtained by the present invention belongs to aluminosilicate glass, which ensures that the strength and toughness of the obtained flexible glass are higher than those of ordinary silicate glass;

[0018] 2. Adding CaO and controlling its content can reduce the viscosity of glass, promote glass melting and clarification, and increase the chemical stability and flexibility of glass;

[0019] 3. Join Y 2 O 3 It can effectively reduce the melting and clarification temperature of glass and the forming and thinning temperature, and at the same time can increase the elastic modulus of glass and thus enhance the flexibility of glass;

[0020] 4. Adding MgO can not only reduce the high temperature viscosity of glass, but also improve the crystallization performance of glass;

[0021] 5. Add ZrO 2 and TiO 2 , improve the strength of the glass, and at the same time optimize the glass structure and improve performance during the annealing process;

[0022] 6. Join Li 2 O can significantly reduce the melting temperature of glass and, under certain conditions, can improve the internal structure and performance of glass, but it will also increase the tendency of glass crystallization;

[0023] 7. Join La 2 O 3 It is an important rare earth oxide that 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.

[0024] Therefore, the produced glass 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

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] Weigh the batch materials according to the following mass percentages:

[0028] 58% SiO 2 , 13% Al 2 O 3 、4.2% MgO、14% Na 2 O, 3% K 2O, 5% CaO, 0.4% ZrO 2 , 0.1% TiO 2 , 0.6% La 2 O 3 , 0.2% Y 2 O 3 , 1.5% Li 2 O. In this embodiment, the raw material is Li 2 O、Na 2 O.K 2 O, in actual use, the raw material is Li 2 CO 3 、Na 2 CO 3 , K 2 CO 3 .

[0029] S1. Mix the raw materials evenly, add them into a platinum crucible and melt them at a melting temperature of 1610°C for 3 hours;

[0030] S2. Cast the melted glass into a copper mold, and put the casted glass into an annealing furnace. During annealing, the annealing curve is used to control the annealing temperature at 580°C and the holding time is 1 hour. After the annealing, the glass is cooled to room temperature in the furnace and taken out to obtain a flexible glass suitable for down-drawing production.

[0031] Example 2

[0032] Weigh the batch materials according to the following mass percentages:

[0033] 64% SiO 2 , 12% Al 2 O 3 、2.5% MgO、12% Na 2 O, 2.5% K 2 O, 3.3% CaO, 0.2% ZrO 2 , 0.6% TiO 2 , 0.4% La 2 O 3 , Y of 0.5 2 O 3 , 2% Li 2 O. In this embodiment, the raw material is Li 2 O、Na 2 O.K 2 O, in actual use, the raw material is Li 2 CO 3 、Na 2 CO 3 , K 2 CO 3 .

[0034] S1. Mix the raw materials evenly, add them into a platinum crucible and melt them at a melting temperature of 1610°C for 3 hours;

[0035] S2. Cast the melted glass into a copper mold, and put the casted glass into an annealing furnace. During annealing, the annealing curve is used to control the annealing temperature to 630°C and the holding time to 1 hour. After the annealing, the glass is cooled to room temperature in the furnace and taken out to obtain a flexible glass suitable for down-drawing production.

[0036] Example 3

[0037] Weigh the batch materials according to the following mass percentages:

[0038] 67% SiO 2 , 8% Al 2 O 3 、3.5% MgO、10% Na 2 O. 5% K 2 O, 1.5% CaO, 0.5% ZrO 2 , 0.5% TiO 2 , 0.7% La 2 O 3 , 0.3% Y 2 O 3 , 3% Li 2 O. In this embodiment, the raw material is Li 2 O、Na 2 O.K 2 O, in actual use, the raw material is Li 2 CO 3 、Na 2 CO 3 , K 2 CO 3 .

[0039] 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;

[0040] S2. Cast the melted glass into a copper mold, and put the casted glass into an annealing furnace. During annealing, the annealing curve is used to control the annealing temperature to 680°C and the holding time to 1 hour. After the annealing, the glass is cooled to room temperature in the furnace and taken out to obtain a flexible glass suitable for down-drawing production.

[0041] Comparative Example 1

[0042] Weigh the batch materials according to the following mass percentages:

[0043] 63% SiO 2 , 15% Al2 O 3 、2.7% MgO、11% Na 2 O, 4% K 2 O, 2% CaO, 0.7% ZrO 2 , 0.4% TiO 2 , 0.1% La 2 O 3 , 0.1% Y 2 O 3 , 1% Li 2 O. In this embodiment, the raw material is Li 2 O、Na 2 O.K 2 O, in actual use, the raw material is Li 2 CO 3 、Na 2 CO 3 , K 2 CO 3 .

[0044] S1. Mix the raw materials evenly, add them into a platinum crucible and melt them at a melting temperature of 1620°C for 3 hours;

[0045] S2. Cast the melted glass into a copper mold, and put the casted glass into an annealing furnace. During annealing, the annealing curve is used to control the annealing temperature to 650°C and the holding time to 1 hour. After the annealing, the glass is cooled to room temperature in the furnace and taken out to obtain a flexible glass suitable for down-drawing production.

[0046] Comparative Example 2

[0047] Weigh the batch materials according to the following mass percentages:

[0048] 67% SiO 2 , 12% Al 2 O 3 、2.5% MgO、12% Na 2 O, 2.5% K 2 O, 4% CaO. In this embodiment, the raw materials are Na 2 O.K 2 O, in actual production, the raw material is Na 2 CO 3 , K 2 CO 3 .

[0049] S1. Mix the raw materials evenly, add them into a platinum crucible and melt them at a melting temperature of 1630°C for 3 hours;

[0050] S2. Cast the melted glass into a copper mold, and put the casted glass into an annealing furnace. During annealing, the annealing curve is used to control the annealing temperature to 680°C and the holding time to 1 hour. After the annealing, the glass is cooled to room temperature in the furnace and taken out to obtain a flexible glass suitable for down-drawing production.

[0051] Comparative Example 3

[0052] Weigh the batch materials according to the following mass percentages:

[0053] 67% SiO 2 , 12% Al 2 O 3 、2.5% MgO、12% Na 2 O, 2.5% K 2 O, 3.8% CaO, 0.2% ZrO 2 In this embodiment, the raw material is Na 2 O.K 2 O, in actual production, the raw material is Na 2 CO 3 , K 2 CO 3 .

[0054] S1. Mix the raw materials evenly, add them into a platinum crucible and melt them at a melting temperature of 1640°C for 3 hours;

[0055] S2. Cast the melted glass into a copper mold, and put the casted glass into an annealing furnace. During annealing, the annealing curve is used to control the annealing temperature to 650°C and the holding time to 1 hour. After the annealing, the glass is cooled to room temperature in the furnace and taken out to obtain a flexible glass suitable for down-drawing production.

[0056] The glasses obtained from Examples 1-3 and Comparative Examples 1-3 were subjected to the following performance tests according to different test standards:

[0057] The surface tension is measured using the national standard GB / T 39797-2021 "Test method for surface tension of glass melts - sessile drop method";

[0058] The elastic modulus is determined using the national standard GB / T 37788-2019 "Test method for elastic modulus of ultra-thin glass";

[0059] The fracture toughness is measured using the national standard GB / T 37900-2019 "Ultra-thin glass hardness and fracture toughness test method - small load Vickers hardness indentation method";

[0060] The glass composition and the measured results are shown in the following table:

[0061]

[0062]

[0063] It can be seen from the above table that the produced 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.

[0064] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] The above contents are merely examples and explanations of the present invention. Those skilled in the art 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 shall all fall within the protection scope of the present invention.

Claims

1. A flexible glass suitable for down-draw production, characterized in that: Made of the following raw materials in percentage by mass: 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; Among them, 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%.

2. The method for preparing flexible glass suitable for down-draw production according to claim 1, characterized in that: The following steps are involved: S1. Mix the raw materials evenly and add them into a platinum crucible for melting; S2. Cast the molten glass into a copper mold, put the casted glass into an annealing furnace, and control the annealing curve during annealing. After the annealing is completed, cool it to room temperature with the furnace, and take it out to obtain a flexible glass suitable for down-draw production.

3. The method for preparing flexible glass suitable for down-draw production according to claim 2, characterized in that: In step S1, the melting temperature is 1580°C-1650°C, and the holding time is 3 hours.

4. The method for preparing flexible glass suitable for down-draw production according to claim 2, characterized in that: In step S2, the annealing temperature is 580°C-680°C, and the holding time is 1 hour.

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