OLED Glass with Excellent Optical Properties

Abstract

The OLED glass with excellent optical properties belongs to the field of glass production and manufacturing, and is manufactured from raw materials with weight percentages of SiO2 being 57 - 62%, Al2O3 being 20 - 24%, B2O3 being 0.5 - 2%, BaF2 being 2 - 5%, SrO being 8 - 11%, BeF2 being 0.5 - 1.5%, SnO2 being 0.2 - 0.5%, La2O3 being 0.3 - 1.0%, P2O5 being 0.2 - 1.0%, AlF3 being 0.2 - 0.8%, and AgNO3 being 0.1 - 0.3%. After sieving silicon dioxide and aluminum oxide and stirring them evenly, the remaining raw materials are weighed and mixed evenly. Then, through melting, stretching and forming in the tin bath area, annealing, cutting, and breaking, the finished product is obtained. The glass not only meets the use performance of optical glass, but also has excellent mechanical properties and thermal properties, so it has good application possibilities in the OLED glass and display industries.

Description

Technical Field

[0001] The present invention relates to the field of glass production and manufacturing, and more specifically, to OLED glass with excellent optical performance.

Background Art

[0002] With the rapid development of the electronic information display industry, display products have evolved from CRT (cathode ray tube) to lightweight and thin LCD (liquid crystal display), and further to OLED (organic electroluminescence), which is the third-generation display technology. OLED has advantages such as self-luminescence, wide viewing angle, low power consumption, high contrast ratio, fast response speed, and can be used for flexible displays. Currently, it is widely used in fields such as televisions and tablets. The glass substrate is a fundamental material for OLED displays and is mainly used in the TFT manufacturing process and as a support plate for CF devices, with related electrical circuits and manufacturing process processing applied to the glass surface. OLED display products have a sandwich structure with organic light-emitting materials sandwiched inside. Also, due to the digitalization and high definition of display devices progressing, the requirements for materials used in optical elements for the devices are also extremely high. Therefore, the indispensable glass substrate also needs to meet special requirements including high transmittance, low photoelastic coefficient, high Abbe number, high strain point, high hardness, and high elastic modulus. Thus, the glass substrate is an irreplaceable inorganic non-metallic material for OLEDs and plays an important role in the display industry.

[0003] At present, glass substrates that can be used for OLED displays can basically meet the needs in terms of performance such as strain points, hardness, and transmittance. However, there is little research on the optical properties of OLED glass, such as its photoelastic coefficient, Abbe number, and elastic modulus. If the optical properties are inferior and the uniformity inside the glass is not good, anisotropy will occur, resulting in non-uniform glass performance and deteriorated reproducibility. For example, regarding the photoelastic coefficient of glass, when force is applied to the glass, anisotropy occurs and the phenomenon of birefringence occurs. When the internal structure of the glass is non-uniform or the residual stress is large, the photoelastic coefficient becomes large, further affecting various properties of the glass. On the other hand, glass with a small photoelastic coefficient has good isotropy, meaning it is more suitable for the manufacture of optical devices. In addition, various defects in OLED glass have a great impact on the optical properties and mechanical properties of the glass. Speaking of the compounding raw materials of the glass, mainly, silicon and aluminum raw materials are often used in OLED glass. However, due to the non-uniformity and particle size unevenness of silicon and aluminum raw materials, defects such as knots and stones often occur, greatly reducing various properties of the glass. Moreover, since there is very little research on the defects caused by this type of glass raw material, this type of glass is inferior in optical properties and has a low product yield. However, in order to improve the display quality of images, it is necessary to make the display glass of high quality and reduce defects.

[0004] In addition, some researchers have added raw materials that are extremely harmful to the environment, such as Pb and V, to the glass for optical devices for displays. Although this type of device is excellent in performance, it cannot be used in large quantities. Furthermore, some researchers are manufacturing optical glass using at least two or more rare earth raw materials in the glass raw materials. However, in this case, the manufacturing cost of the glass increases, making it difficult to popularize and apply.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The object of the present invention is to provide an OLED glass with excellent optical performance in order to solve the problems of conventional display glasses such as OLEDs, which have a high photoelastic coefficient, a low Abbe number, a low elastic modulus, non-uniform performance inside the glass, a high defect rate caused by silicon and aluminum raw materials, and a low product yield. The glass of the present invention has a low defect rate, a low melting point, a high transmittance, a small photoelastic coefficient, a high Abbe number, a high strain point, elastic modulus and Vickers hardness, and these physical and chemical properties have high uniformity. In addition, on the premise of effectively reducing the process difficulty in the float forming process of the glass and ensuring high mechanical performance, the optical performance of the glass is greatly improved and the product yield is improved. Moreover, the glass of the said chemical composition is easy to manufacture and easy to realize.

Means for Solving the Problems

[0006] The object of the present invention can be achieved by the following technical means.

[0007] The OLED glass with excellent optical performance is manufactured from raw materials with weight percentages of SiO2 being 57 - 62%, Al2O3 being 20 - 24%, B2O3 being 0.5 - 2%, BaF2 being 2 - 5%, SrO being 8 - 11%, BeF2 being 0.5 - 1.5%, SnO2 being 0.2 - 0.5%, La2O3 being 0.3 - 1.0%, P2O5 being 0.2 - 1.0%, AlF3 being 0.2 - 0.8%, and AgNO3 being 0.1 - 0.3%.

[0008] Furthermore, the OLED glass is manufactured from raw materials with weight percentages of SiO2 being 57 - 62%, Al2O3 being 20 - 24%, B2O3 being 0.5 - 2%, BaF2 being 2 - 4%, SrO being 8 - 10%, BeF2 being 0.6 - 1.2%, SnO2 being 0.2 - 0.5%, La2O3 being 0.3 - 0.8%, P2O5 being 0.2 - 0.8%, AlF3 being 0.2 - 0.7%, and AgNO3 being 0.1 - 0.25%.

[0009] Furthermore, the OLED glass is manufactured from raw materials with the following weight percentages: 57-62% SiO2, 20-24% Al2O3, 0.5-2% B2O3, 2-4% BaF2, 8-10% SrO, 0.6-1.2% BeF2, 0.2-0.5% SnO2, 0.3-0.8% La2O3, 0.2-0.6% P2O5, 0.3-0.7% AlF3, and 0.1-0.25% AgNO3.

[0010] Furthermore, the usage ratios of the above raw materials are 21.5wt%≦Al2O3+B2O3+BeF≦26wt%, 3.5wt%≦BaF2+BeF2+AlF3≦6.5wt%, 21wt%≦P2O5+Al2O3≦25wt%, and 5.5wt%≦BaF2+BeF2+AlF3+La2O3+P2O5≦7.8wt%.

[0011] SiO2 is a glass network former and has sp 3 Hybrid orbitals constitute the basic structural unit of silicate, [SiO4]. That is, SiO2 is one of the most important raw materials in OLED glass. SiO2 reduces the thermal expansion coefficient of glass, and can improve the chemical stability, mechanical strength, and transmission performance of glass. However, if the content is high, the melting temperature becomes high and crystals are easily precipitated. Therefore, taking into consideration the properties of the glass of the present invention, the range of SiO2 is set to 57 to 62%.

[0012] B2O3 is a glass network former, and with [BO3] and [BO4] as structural units, it can improve the chemical stability and thermal stability of glass and improve the luster of glass. It can also lower the viscosity of glass at high temperatures and act as a flux. In addition, B2O3 can significantly lower the surface tension of glass as a surfactant, but if added in excess, it will actually reduce the performance of the glass. Therefore, the appropriate range of B2O3 in the present invention is 0.5-2%, and 21.5wt%≦Al2O3+B2O3+BeF≦26wt%.

[0013] Al2O3 is a glass network intermediate, has two types of coordination states, and is located in tetrahedra or octahedra.3+ , Be 2+ , when included, has a tendency to bond with oxygen ions, interferes with tetrahedral coordination, and some Al 3+ may be located in the octahedron. Aluminum can improve the glass structure by forming an aluminum-oxygen tetrahedron with oxygen having a double bond in the phosphorus-oxygen glass. Aluminum oxide can significantly improve the performance of the glass such as hardness, elastic modulus, and strain point. However, if the content is too high, the melting temperature will increase. Therefore, in the present invention, the appropriate range of Al2O3 is 20 - 24%, and 21.5 wt% ≦ Al2O3 + B2O3 + BeF ≦ 26 wt%, 21 wt% ≦ P2O5 + Al2O3 ≦ 25 wt%.

[0014] BaF, BeF, and AlF3 are fluorides introduced into the glass, which can strengthen the vitrification ability of the glass and significantly improve the optical performance of the glass. Thereby, the stability of the glass is improved, the light transmission range is expanded, the photoelastic coefficient of the glass is effectively reduced, and the Abbe number of the glass is improved. Also, it has the effect of promoting the melting of the glass and reducing the melting temperature of the glass. However, if introduced excessively, it will destroy the network structure of the glass and affect other properties of the glass. Therefore, the appropriate range of BaF in the present invention is 2 - 5%, the appropriate range of BeF is 0.5 - 1.5%, and the appropriate range of AlF is 0.2 - 0.8%. Also, 3.5 wt% ≦ BaF2 + BeF2 + AlF3 ≦ 6.5 wt%, 5.5 wt% ≦ BaF2 + BeF2 + AlF3 + La2O3 + P2O5 ≦ 7.8 wt%.

[0015] La2O3 is a rare earth oxide and has a relatively compact electron layer structure. The presence of La 3+ in the network voids of the glass can effectively improve the optical performance of the glass, reduce the light dispersion of the glass, and make it possible to have a high Abbe number. In the present invention, the appropriate range is 0.3 - 0.8%, and 5.5 wt% ≦ BaF2 + BeF2 + AlF3 + La2O3 + P2O5 ≦ 7.8 wt%.

[0016] P2O5 is a glass - forming oxide. By forming the network structure of phosphate glass with [PO4], it can improve the dispersion coefficient and ultraviolet - transmission ability of the glass and lower the melting temperature of the glass. In addition, P2O5 has strong surface activity and can significantly reduce the surface tension of the glass. However, if the content is too high, the stability of the glass will decrease. Summarizing the above, the specific range of P2O5 in the present invention is 0.2 - 1.0%, and 21 wt% ≤ P2O5 + Al2O3 ≤ 25 wt%.

[0017] The OLED glass with excellent optical performance includes the following steps as a manufacturing method.

[0018] (1) First, sieve silicon dioxide and aluminum oxide with a desired mesh number. Next, stir evenly with a mixer to prevent the generation of defects such as silicon - rich phases, aluminum - rich phases, or undissolved silicon and aluminum in the finished glass product.

[0019] (2) After all raw materials are weighed, put them into a mixer together with the above - mentioned silicon - aluminum batch materials, mix them evenly, and convey them to the inlet for feeding.

[0020] (3) Melt the glass raw materials, draw and form them in the tin - bath area, and then convey them to the annealing furnace with rollers. Then, perform forming processes such as precision annealing, cutting, and breaking, and detect each performance of the glass after completion.

Advantages of the Invention

[0021] The beneficial effects of the present invention: 1. Different from the conventional general OLED glass, the glass of the present invention has a low melting temperature and a high characteristic - point temperature. The range of the melting temperature is 1703 - 1709 °C, and the strain - point temperature reaches up to 750 °C at most. Also, it has high mechanical properties, with a Vickers hardness of 705 MPa and an elastic modulus reaching 86.12 GPa. In addition, it has excellent optical performance, with a transmittance reaching 91.8%. Moreover, the photo - elastic coefficient is 13% lower than that of general OLED glass, and the Abbe number is improved by 17%.

[0022] 2. According to the method of sieving the above glass raw materials in the present invention with a sieve of 80 to 120 mesh and stirring twice, the density of defects such as knots and undissolved nodules in the silicon-aluminum quality of the glass is significantly reduced, and the yield of the product is improved by 2 to 3%.

[0023] 3. On the premise of ensuring the mechanical properties such as high elastic modulus and high Vickers hardness of the glass of the present invention, the optical performance of the glass is improved, and the application range of the glass is expanded. In addition, the melting difficulty and the stretching forming difficulty of the glass are reduced, and the yield of the product is improved.

Embodiments for Carrying Out the Invention

[0024] Next, in combination with the embodiments of the present invention, the technical means in the embodiments of the present invention will be described clearly and concisely. Needless to say, the described embodiments are only a 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 on the premise that those skilled in the art do not perform creative labor all belong to the protection scope of the present invention.

[0025] Examples 1 to 5 The OLED glass with excellent optical performance contains silicon dioxide, aluminum oxide, boric acid, barium fluoride, strontium carbonate, beryllium fluoride, tin dioxide, lanthanum oxide, diphosphorus pentoxide, aluminum fluoride and silver nitrate as glass raw materials. In Examples 1 to 5, they were respectively weighed based on the blending ratios in Table 1.

[0026] The glasses of Examples 1 to 5 were all prepared by the following steps.

[0027] (1) First, select a sieve of 80 to 120 mesh and sieve silicon dioxide and aluminum oxide. Next, stir evenly with a mixer to prevent the generation of defects such as silicon-rich phase, aluminum-rich phase or undissolved substances of silicon and aluminum in the finished glass product.

[0028] (2) After weighing all the remaining raw materials, they were put into a mixer together with the above silicon-aluminum batch material and mixed uniformly again, and then conveyed to the inlet and fed in.

[0029] (3) After melting the glass raw materials and stretching and forming them in the tin bath area, they were conveyed to the annealing furnace by rollers. Then, forming processes such as precision annealing, cutting, and folding were carried out, and after completion, the various performances of the glass were detected.

[0030] Comparative Example (1) All the raw materials were weighed at the ratios shown in Table 1, put into a mixer and mixed uniformly, and then conveyed to the inlet and fed in.

[0031] (2) After melting the glass raw materials and stretching and forming them in the tin bath area, they were conveyed to the annealing furnace by rollers. Then, forming processes such as precision annealing, cutting, and folding were carried out, and after completion, the various performances of the glass were detected.

[0032] Performance tests were carried out on the lithium aluminosilicate glass obtained in Examples 1 to 5 and the comparative example. The treatment conditions and test results were as shown in Table 1 below.

[0033]

Table 1

[0034] The present invention mainly targets OLED glass systems. While the comparative examples in Table 1 belonged to general OLED glass, the glasses of Examples 1 to 5 had obvious differences in mechanical properties, thermal properties, and optical performance. The melting and clarification temperature of the glass of the examples was clearly low, and the temperature of the corresponding characteristic points was also low. In addition, the temperatures of the softening point, strain point, and devitrification point were all high, completely meeting the temperature process in the manufacturing process of OLEDs. Moreover, the glass had excellent optical performance, with high transmittance, a small photoelastic coefficient, a high Abbe number, and high uniformity of optical performance. When comparing the comparative examples with Examples 1 to 5, by sieving the glass raw materials to make the particle size uniform and adding a raw material mixing process, the density of defects such as knots and undissolved stones in the silicon-aluminum quality of the glass was significantly reduced. The glass of the present invention improves the optical performance of the glass and expands the application range of the glass on the premise of ensuring mechanical properties such as high elastic modulus and high Vickers hardness. In addition, the melting difficulty and stretching forming difficulty of the glass are reduced, and the product yield is improved.

[0035] In the description of the specification, references to terms such as "one embodiment", "exemplification", "specific exemplification", etc. mean that the specific features, structures, materials, or characteristics described in combination with the embodiment or exemplification are included in at least one embodiment or exemplification of the present invention. Also, in this specification, the general description of the above terms does not necessarily indicate the same embodiment or exemplification. And the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or exemplifications.

[0036] The above content is only an exemplification and explanation of the present invention. Any various modifications, supplements, or replacements in a similar manner made by those skilled in the art to the described specific embodiments shall fall within the protection scope of the present invention as long as they do not deviate from the invention or exceed the scope defined in the claims.

Claims

1. SiO ２ is 57 - 62%, Al ２ O ３ is 20 - 24%, B ２ O ３ is 0.5 - 2%, BaF ２ is 2 - 5%, SrO is 8 - 11%, BeF ２ is 0.5 - 1.5%, SnO ２ is 0.2 - 0.5%, La ２ O ３ is 0.3 - 1.0%, P ２ O ５ is 0.2 - 1.0%, AlF ３ is 0.2 - 0.8%, AgNO ３ is made from raw materials with weight percentages of 0.1 - 0.3%, and is characterized by excellent optical performance of OLED glass.

2. SiO ２ is 57 - 62%, Al ２ O ３ is 20 - 24%, B ２ O ３ is 0.5 - 2%, BaF ２ is 2 - 4%, SrO is 8 - 10%, BeF ２ is 0.6 - 1.2%, SnO ２ is 0.2 - 0.5%, La ２ O ３ is 0.3 - 0.8%, P ２ O ５ is 0.2 - 0.8%, AlF ３ is 0.2 - 0.7%, AgNO ３ The OLED glass excellent in optical performance according to claim 1, which is manufactured from raw materials in weight percentages of 0.1 - 0.25%.

3. SiO ２ is 57 - 62%, Al ２ O ３ is 20 - 24%, B ２ O ３ is 0.5 - 2%, BaF ２ is 2 - 4%, SrO is 8 - 10%, BeF ２ is 0.6 - 1.2%, SnO ２ is 0.2 - 0.5%, La ２ O ３ is 0.3 - 0.8%, P ２ O ５ is 0.2 - 0.6%, AlF ３ is 0.3 - 0.7%, AgNO ３ is made from raw materials in weight percentages of 0.1 - 0.25%, and the OLED glass according to claim 1, which is characterized by excellent optical performance.

4. The usage ratio of the above raw materials is 21.5 wt% ≤ Al ２ O ３ + B ２ O ３ + BeF ≤ 26 wt%, 3.5 wt% ≤ BaF ２ + BeF ２ + AlF ３ ≤ 6.5 wt%, 21 wt% ≤ P ２ O ５ + Al ２ O ３ ≤ 25 wt%, 5.5 wt% ≤ BaF ２ + BeF ２ + AlF ３ + La ２ O ３ + P ２ O ５ ≤ 7.8 wt%, and the OLED glass with excellent optical performance according to claim 1 is characterized in that.

5. As a manufacturing method, (1) First, sieving silicon dioxide and aluminum oxide with a desired mesh number, and then obtaining a silicon-aluminum batch material by uniformly stirring with a mixer; (2) After weighing all the remaining raw materials, putting them into a mixer together with the above silicon-aluminum batch material, uniformly mixing, and conveying and charging them to the charging port; (3) Melting the glass raw materials, stretching and forming them in the tin bath area, then conveying them to an annealing furnace with rollers, and performing precision annealing, cutting, and folding forming processes to obtain the OLED glass. The OLED glass having excellent optical performance according to claim 1, characterized by comprising the above steps.

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