Composition for glass substrate, blue light filtering alkali-free glass substrate, and preparation method and application thereof

Abstract

The present invention relates to the field of glass and discloses a composition for a glass substrate, wherein the composition comprises the following components: SiO 2 、Al 2 O 3 , B 2 O 3 、CaO、RO、Y 2 O 3 , Pr 2 O 3 SnO 2 Based on the total mole of the composition, the SiO 2 The content of Al 2 O 3 The content of B is 8-16 mol%. 2 O 3 The content of is 3-7 mol%, the content of CaO is 7-12 mol%, the content of RO is 1-13 mol%, the content of Y 2 O 3 The content of Pr is 0.5-3 mol%. 2 O 3 The content of SnO is 0.5-2 mol%. 2 The content of RO is 0-0.5 mol%; wherein the RO is selected from at least one of MgO, SrO, BaO, and ZnO; the blue light filtering glass substrate provided by the present invention takes into account better physical and chemical properties and blue light filtering effects, and can be applied to display devices that have higher requirements on glass substrate performance.

Description

Technical Field

[0001] The present invention relates to the field of glass, and in particular to a composition for a glass substrate, a blue light filtering alkali-free glass substrate, and a preparation method and application thereof. Background Art

[0002] Glass substrate materials are used in substrates, hard disks, filters, and protective covers of sensors used in liquid crystal displays or organic self-luminous (EL) displays. In particular, in the field of liquid crystal displays, active matrix liquid crystal displays (AMLCDs) in which pixels are driven by active elements, represented by glass transistors (hereinafter referred to as TFT, Thin Film Transistor), have become mainstream, and are widely used in color or animation displays such as LCD TVs, laptop computers, mobile phones, and digital camera displays.

[0003] However, as a glass substrate material for liquid crystal displays, it is generally required to have the following characteristics, such as:

[0004] (1) It does not contain alkali metal ions, which prevents the alkali metal ions in the glass substrate from diffusing in the liquid crystal display film and causing deterioration of the film properties;

[0005] (2) It has good chemical durability to meet the various chemical reagents that the TFT manufacturing process is subjected to, including the X and / or SiN X Buffered hydrofluoric acid for thin film etching, hydrochloric acid-containing solution for ITO conductive film etching, and various acids (nitric acid, sulfuric acid) for metal electrode etching, etc.;

[0006] (3) Having a suitable thermal expansion coefficient to match the thermal expansion coefficient of the a-Si or p-Si material formed on the surface of the glass substrate;

[0007] (4) It has a higher strain point, which prevents the glass substrate from being exposed to high temperature and easily causes deformation and shrinkage of the glass substrate to a minimum. In particular, for polycrystalline silicon (p-Si) transistor devices, compared with the preparation of a-Si transistors, p-Si transistors require a higher preparation process temperature. Therefore, as a glass substrate carrying p-Si, its corresponding strain point temperature is also required to be higher;

[0008] (5) It has a high Young's modulus to prevent the glass substrate from bending and causing defects, which is of great significance for achieving mass production of large-generation glass substrates;

[0009] In addition to the above requirements for the physical and chemical conditions of the glass substrate itself, from the perspective of the glass substrate production process, the glass substrate must also meet the following requirements:

[0010] a. The glass has good melting properties to avoid the occurrence of melting defects such as bubbles, particles and veins;

[0011] b. It has good resistance to devitrification, preventing the glass substrate from crystallizing during the molding process and causing the appearance of devitrification foreign matter.

[0012] In addition, with the rapid popularization of electronic products, people can come into contact with liquid crystal display related products everywhere in their lives. However, researchers have found that when people often use electronic products related to liquid crystal display, they will emit a certain amount of short-wave blue light, such as OLED display technology, which contains tens of millions of solid microparticles inside, which can automatically emit light. As long as the voltage is input into the electrode, the excitation layer can produce the required color light. Among them, the blue light band it produces is mainly concentrated in 435nm-450nm. The blue light in this band has a short wavelength and high energy, which is the most harmful to the human eye. If the human eye is exposed to blue light radiation for a long time, it will cause eye diseases such as macular degeneration.

[0013] Therefore, as a glass substrate for liquid crystal display, on the premise of satisfying the above physical and chemical properties, the glass substrate can be further endowed with the function of anti-blue light, which is of great significance for further improving the performance of liquid crystal display products. Summary of the invention

[0014] The purpose of the present invention is to overcome the problem that the physical and chemical properties and blue light protection of the glass substrate in the prior art cannot be taken into account at the same time.

[0015] In order to achieve the above object, the first aspect of the present invention provides a composition for a blue light filtering alkali-free glass substrate, wherein the composition comprises two or more of the following components which are mixed or stored separately:

[0016] SiO2, Al2O3, B2O3, CaO, RO, Y2O3, Pr2O3, SnO2;

[0017] Based on the total mole of the composition, the content of SiO2 is 60-73mol%, the content of Al2O3 is 8-16mol%, the content of B2O3 is 3-7mol%, the content of CaO is 7-12mol%, the content of RO is 1-13mol%, the content of Y2O3 is 0.5-3mol%, the content of Pr2O3 is 0.5-2mol%, and the content of SnO2 is 0-0.5mol%;

[0018] Wherein, the RO is selected from at least one of MgO, SrO, BaO and ZnO;

[0019] The content M1 of Y2O3, the content M2 of Pr2O3, the content M3 of RO, the content M4 of CaO, and the content M5 of Al2O3 satisfy formula (1) and formula (2):

[0020] Formula (1): M2≤M1, and 1mol%≤M1+M2≤4mol%;

[0021] Formula (2): M4>M3, and 1≤(M4+M3+1.5×(M1+M2)) / M5≤1.5.

[0022] Preferably, based on the total mole of the composition, the content of SiO2 is 64-69mol%, the content of Al2O3 is 11-15mol%, the content of B2O3 is 4-7mol%, the content of CaO is 8-10mol%, the content of RO is 1-3mol%, the content of Y2O3 is 1-2mol%, the content of Pr2O3 is 0.5-2mol%, and the content of SnO2 is 0-0.5mol%.

[0023] Preferably, in the RO, based on the total mole of the composition, the content of MgO is 1-5 mol%, the content of SrO is 0-3 mol%, the content of BaO is 0-3 mol%, and the content of ZnO is 0-2 mol%.

[0024] Preferably, the content M1 of Y2O3 and the content M2 of Pr2O3 satisfy formula (3):

[0025] Formula (3): M2≤M1, and 3mol%≤M1+M2≤4mol%.

[0026] More preferably, based on the total mole of the composition, the content of SiO2 is 68.5-69 mol%, the content of Al2O3 is 11-12 mol%, the content of B2O3 is 6-7 mol%, the content of MgO is 1-2 mol%, the content of CaO is 8-9 mol%, the content of Y2O3 is 1-2 mol%, and the content of Pr2O3 is 1-2 mol%;

[0027] The content M1 of Y2O3 and the content M2 of Pr2O3 satisfy formula (4):

[0028] Formula (4): M2≤M1, 3.5mol%≤M1+M2≤4mol%.

[0029] The second aspect of the present invention provides a method for preparing a blue light filtering alkali-free glass substrate, which comprises mixing the components in the composition for a blue light filtering alkali-free glass substrate according to the first aspect and then sequentially performing melting treatment, molding treatment and annealing treatment.

[0030] The third aspect of the present invention provides a blue light filtering alkali-free glass substrate prepared by the method described in the second aspect.

[0031] Preferably, the glass substrate has the following properties:

[0032] (1) The strain point is not less than 752°C;

[0033] (2) Young’s modulus is not less than 82.4 GPa;

[0034] (3) Annealing point is not less than 791°C;

[0035] (4) The thermal expansion coefficient is 33×10 -7 -42×10 -7 / ℃;

[0036] (5) Temperature T corresponding to a viscosity of 200 poise 200 ≤1611;

[0037] (6) Density not higher than 2.7g / cm 3 .

[0038] Preferably, the short-wave blue light transmittance T of the glass substrate is (430-480nm) ≤5.6%.

[0039] The fourth aspect of the present invention provides application of the blue light filtering alkali-free glass substrate described in the third aspect in a display device.

[0040] Preferably, the blue light filtering alkali-free glass substrate is used in a TFT-LCD glass substrate and / or an OLED glass substrate.

[0041] Under the premise of controlling the contents of SiO2, Al2O3, B2O3, CaO, RO and SnO2, the present invention blends Y2O3 and Pr2O3 and accurately adjusts their dosage, which can give the glass substrate excellent blue light filtering performance and also improve the physical and chemical properties of the glass substrate.

[0042] In particular, the blue light filtering alkali-free glass substrate provided by the present invention has a strain point of up to 835°C, an annealing point of up to 873°C, a Young's modulus of up to 87.9 GPa, and a short-wave blue light transmittance T (430-480nm) As low as 2.9%, it can be used in display devices that have higher requirements on glass substrate performance, such as polysilicon transistor semiconductor devices that require higher heat treatment, and is also more conducive to the large-scale industrial production of high-generation glass substrates. DETAILED DESCRIPTION

[0043] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0044] As mentioned above, the first aspect of the present invention provides a composition for a blue light filtering alkali-free glass substrate, wherein the composition contains two or more of the following components which are mixed or stored separately:

[0045] SiO2, Al2O3, B2O3, CaO, RO, Y2O3, Pr2O3, SnO2;

[0046] Based on the total mole of the composition, the content of SiO2 is 60-73mol%, the content of Al2O3 is 8-16mol%, the content of B2O3 is 3-7mol%, the content of CaO is 7-12mol%, the content of RO is 1-13mol%, the content of Y2O3 is 0.5-3mol%, the content of Pr2O3 is 0.5-2mol%, and the content of SnO2 is 0-0.5mol%;

[0047] Wherein, the RO is selected from at least one of MgO, SrO, BaO and ZnO;

[0048] The content M1 of Y2O3, the content M2 of Pr2O3, the content M3 of RO, the content M4 of CaO, and the content M5 of Al2O3 satisfy formula (1) and formula (2):

[0049] Formula (1): M2≤M1, and 1mol%≤M1+M2≤4mol%;

[0050] Formula (2): M4>M3, and 1≤(M4+M3+1.5×(M1+M2)) / M5≤1.5.

[0051] It should be noted that the units of M1, M2, M3, M4 and M5 in formula (1) and formula (2) are mol%.

[0052] In the present invention, the composition for blue light filtering alkali-free glass substrate should be understood as the composition does not need to be further added with an alkali metal component, and the alkali metal component can be added in the form of any single substance or compound containing an alkali metal element, and the alkali metal component includes Li, Na and / or K. It can also be understood as the content of alkali metal oxides (Li2O, Na2O, K2O) in the glass component is less than 0.1 mol%.

[0053] The inventors of the present invention have limited the content range of each component in the composition for blue light filtering alkali-free glass substrate provided by the present invention based on the following considerations:

[0054] When SiO2 is a glass network former and its content is too low, the chemical stability of the obtained glass substrate, especially the acid resistance, deteriorates; when the SiO2 content is too high, the high temperature viscosity of the obtained glass substrate increases greatly, making the melting property of the glass component deteriorate. Therefore, after extensive research, the inventors of the present invention limit the content of SiO2 to 60-73 mol%.

[0055] Al2O3 is a glass intermediate oxide. When its content is too low, the strain point of the glass substrate is easily reduced, and cristobalite devitrification foreign matter is easily present in the glass; when the content of Al2O3 is too high, the buffered fluoride acid resistance (BHF resistance) of the glass substrate is deteriorated, and the surface of the glass substrate is prone to white turbidity. Therefore, after extensive research, the inventors of the present invention have limited the content of Al2O3 to 8-16 mol%.

[0056] B2O3 is a good glass melting flux, which can improve the meltability of glass and reduce the cost of glass melting. When its content is too low, it cannot fully play its role of fluxing; when the content of B2O3 is too high, it is easy to cause the strain point of the glass to decrease and the acid resistance to deteriorate. Therefore, after a lot of research, the inventors of the present invention limit the content of B2O3 to 3-7 mol%.

[0057] CaO is a component that reduces the high temperature viscosity of glass and improves the melting property of glass. When its content is too high, it will reduce the chemical resistance stability of glass. Therefore, after extensive research, the inventors of the present invention have limited the content of CaO to 7-12 mol%.

[0058] SnO2 is mainly used as a clarifier in the present invention. The valence of Sn ions changes in the high-temperature region, and multiple clarifying gases can be produced, thereby improving the solubility of the glass. At the same time, considering that excessive SnO2 content can easily lead to poor devitrification resistance of the glass, the inventors of the present invention have limited the SnO2 content to 0-0.5 mol% after extensive research.

[0059] In the present invention, Y2O3 and Pr2O3 are introduced into the glass substrate material components as rare earth oxides, which can be used to reduce the high-temperature viscosity of the glass and also increase the Young's modulus of the glass substrate; Pr 3+ As a rare earth ion, it has ff and fd orbital transitions, which makes it have rich energy levels. 3+ The ions can absorb blue light in the 430nm-480nm band, especially the blue light near 450nm. However, excessive Y2O3 and Pr2O3 can easily increase the density of the glass substrate as a whole, which is not conducive to the large-scale production of high-generation glass substrates. Therefore, after extensive research, the inventors of the present invention have limited the content of Y2O3 to 0.5-3mol%, and the content of Pr2O3 to 0.5-2mol%. At the same time, the contents of Y2O3 and Pr2O3 satisfy formula (1).

[0060] In addition, the inventors of the present invention have also found through creative research that when the content of each component satisfies formula (2), the devitrification resistance of the glass can be significantly improved, which is more conducive to the molding of the glass substrate using the overflow down-draw method.

[0061] Preferably, based on the total mole of the composition, the content of SiO2 is 64-69mol%, the content of Al2O3 is 11-15mol%, the content of B2O3 is 4-7mol%, the content of CaO is 8-10mol%, the content of RO is 1-3mol%, the content of Y2O3 is 1-2mol%, the content of Pr2O3 is 0.5-2mol%, and the content of SnO2 is 0-0.5mol%. The inventors found that under this preferred embodiment, the blue light filtering alkali-free glass substrate provided by the present invention has a higher strain point, annealing point and Young's modulus.

[0062] In the present invention, the inventors also found that MgO can reduce the high-temperature viscosity of glass, improve the glass meltability, and reduce the glass density, but if the glass component contains excessive MgO, it is easy to react with BHF buffered fluoric acid to produce white turbidity on the surface of the glass substrate; BaO and SrO can improve the chemical resistance of glass, but too high a content is likely to increase the density of glass and destroy the thermal expansion coefficient of glass; ZnO can improve the BHF resistance and meltability of glass and reduce the thermal expansion coefficient of glass, but too high a content will lead to a significant decrease in the strain point and difficulty in obtaining the desired heat resistance.

[0063] Therefore, preferably, in the RO, based on the total mole of the composition, the content of MgO is 1-5 mol%, the content of SrO is 0-3 mol%, the content of BaO is 0-3 mol%, and the content of ZnO is 0-2 mol%.

[0064] Preferably, the content M1 of Y2O3 and the content M2 of Pr2O3 satisfy formula (3):

[0065] Formula (3): M2≤M1, and 3mol%≤M1+M2≤4mol%. The inventors found that under this preferred embodiment, the blue light filtering alkali-free glass substrate provided by the present invention has a better blue light filtering effect.

[0066] More preferably, based on the total mole of the composition, the content of SiO2 is 68.5-69 mol%, the content of Al2O3 is 11-12 mol%, the content of B2O3 is 6-7 mol%, the content of MgO is 1-2 mol%, the content of CaO is 8-9 mol%, the content of Y2O3 is 1-2 mol%, and the content of Pr2O3 is 1-2 mol%;

[0067] The content M1 of Y2O3 and the content M2 of Pr2O3 satisfy formula (4):

[0068] Formula (4): M2≤M1, 3.5mol%≤M1+M2≤4mol%. The inventors found that under this preferred embodiment, the blue light filtering alkali-free glass substrate provided by the present invention has a higher strain point, annealing point, Young's modulus and better blue light filtering effect.

[0069] The second aspect of the present invention provides a method for preparing a blue light filtering alkali-free glass substrate, which comprises mixing the components in the composition for a blue light filtering alkali-free glass substrate described in the first aspect and then sequentially performing melting treatment, molding treatment and annealing treatment.

[0070] Preferably, the conditions of the melt treatment include: a temperature of 1550-1700° C. and a time of 6-10 h.

[0071] Preferably, the forming process is carried out in a graphite mould.

[0072] Preferably, the annealing treatment conditions include: a temperature of 700° C.-900° C. and a time of 4-8 hours.

[0073] The third aspect of the present invention provides a blue light filtering alkali-free glass substrate prepared by the method described in the second aspect.

[0074] Preferably, the glass substrate has the following properties:

[0075] (1) The strain point is not less than 752°C;

[0076] (2) Young’s modulus is not less than 82.4 GPa;

[0077] (3) Annealing point is not less than 791°C;

[0078] (4) The thermal expansion coefficient is 33×10 -7 -42×10 -7 / ℃;

[0079] (5) Temperature T corresponding to a viscosity of 200 poise 200 ≤1611;

[0080] (6) Density not higher than 2.7g / cm 3 .

[0081] Preferably, the short-wave blue light transmittance T of the glass substrate is (430-480nm) ≤5.6%.

[0082] The fourth aspect of the present invention provides application of the blue light filtering alkali-free glass substrate described in the third aspect in a display device.

[0083] Preferably, the blue light filtering alkali-free glass substrate is used in a TFT-LCD glass substrate and / or an OLED glass substrate.

[0084] The present invention will be described in detail below through examples.

[0085] In the following examples, unless otherwise specified, all raw materials used were commercially available.

[0086] In the following examples, unless otherwise specified, the total amount of the composition is 20 mol.

[0087] In the following examples, the performance testing methods involved are as follows:

[0088] (1) Liquidus temperature: The test was conducted using a gradient furnace (equipment model: Orton GTF-MD-16 series); the test method was as follows: glass powder that passed through a standard sieve of 30 mesh (500 μm) and remained at 50 mesh (300 μm) was placed in a platinum boat, and kept in a temperature gradient furnace within a set temperature range (1100°C-1350°C) for 24 hours. The platinum boat was then taken out and the temperature at which devitrification (appearance of crystalline foreign matter) occurred in the glass was confirmed;

[0089] (2) Liquidus viscosity and temperature (°C) corresponding to viscosity of 200 poise: A rotary high temperature viscometer (equipment model: RSV1700) is used to test to obtain the relationship curve between the viscosity of the glass liquid and temperature at different temperatures; the required liquidus viscosity and temperature (°C) corresponding to viscosity of 200 poise are obtained through the liquidus viscosity curve obtained by the test;

[0090] (3) The test standard of Young's modulus is JIS R1602; it is obtained by resonance method test;

[0091] (4) Density is measured by the Archimedes method (based on ASTM C693) and is expressed in g / cm 3 ;

[0092] (5) Annealing point temperature and strain point temperature: obtained by annealing point strain point temperature tester (equipment model: ANS-800);

[0093] (6) Thermal expansion coefficient (20-300°C): obtained by thermal expansion coefficient tester (equipment model: DIL402Expedis Classic);

[0094] (7) Transmittance of short-wave blue light T (430nm-480nm) : Obtained by UV-Vis spectrophotometer (equipment model: Perkin Elmer Lamda950);

[0095] In the following examples, unless otherwise specified, A represents M4+M3+1.5×(M1+M2), and B represents (M4+M3+1.5×(M1+M2)) / M5.

[0096] Example 1

[0097] This example is used to illustrate that the blue light filtering alkali-free glass substrate of the present invention is prepared according to the formulation in Table 1 and the method described below.

[0098] The method for preparing a blue light filtering alkali-free glass substrate comprises the following steps:

[0099] (1) stirring and mixing the components in the composition for a blue light filtering alkali-free glass substrate uniformly, and then placing the components in a platinum crucible for high-temperature melting treatment to obtain a first material; the melting treatment conditions are: temperature of 1650° C., and time of 8 hours;

[0100] (2) pouring the first material into a graphite mold (size: 200 mm×200 mm×2 mm) preheated to 200° C. for molding to obtain a second material;

[0101] (3) The second material is subjected to annealing treatment to obtain the blue light filtering alkali-free glass substrate, and the annealing treatment conditions are: temperature of 780° C. and time of 6.5 h.

[0102] Unless otherwise specified, the remaining examples were carried out using a process similar to that of Example 1, except that the formulations used in each example were different, as shown in Table 1.

[0103] Table 1

[0104]

[0105]

[0106] Table 1 (Continued)

[0107]

[0108] Test Case

[0109] The above-mentioned test method was used to measure the performance of the blue light filtering alkali-free glass substrates obtained in each embodiment and comparative example. The specific results are shown in Table 2.

[0110] Table 2

[0111]

[0112]

[0113] Table 2 (Continued)

[0114]

[0115] It can be seen from the results in Table 2 that the blue light filtering alkali-free glass substrate provided by the present invention can achieve both better physical and chemical properties and blue light filtering effects.

[0116] Specifically, by adding a specific amount of Y2O3 and Pr2O3 rare earth oxides to the glass substrate components, on the one hand, the high-temperature viscosity of the glass substrate can be reduced, that is, the solubility of the glass substrate can be improved; on the other hand, it can increase the annealing point temperature and strain point temperature of the glass substrate. The glass substrate obtained in this way can be suitable for application scenarios with higher process processing temperatures (such as polysilicon transistor semiconductor devices).

[0117] At the same time, by introducing a specific amount of Pr2O3 into the components of the glass substrate, it can give the glass substrate a better filtering effect in the 430nm-480nm blue light band.

[0118] It can be seen from Example 2 and Comparative Example 3 that when M4<M3, the high-temperature melting property of the obtained glass substrate is relatively poor, and the Young's modulus of the glass substrate is also relatively low.

[0119] It can be seen from Example 3, Comparative Example 4 and Comparative Example 5 that when B is not within the range of the present invention, crystallization is likely to occur inside the obtained glass substrate during the molding process. When the B value is lower than 1, i.e., 0.97, SiO2-Al2O3-based devitrified crystals are likely to precipitate during the molding process of the glass substrate. When the B value exceeds 1.5 and reaches 1.6, devitrified crystals of alkaline earth aluminosilicates such as mullite and anorthite are likely to occur during the molding process of the glass substrate, which is not conducive to the devitrification resistance of the glass substrate.

[0120] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A composition for a blue light filtering alkali-free glass substrate, characterized in that: The composition contains two or more of the following components which are stored in a mixed or separate manner: SiO2, Al2O3, B2O3, CaO, RO, Y2O3, Pr2O3, SnO2; Based on the total mole of the composition, the content of SiO2 is 60-73mol%, the content of Al2O3 is 8-16mol%, the content of B2O3 is 3-7mol%, the content of CaO is 7-12mol%, the content of RO is 1-13mol%, the content of Y2O3 is 0.5-3mol%, the content of Pr2O3 is 0.5-2mol%, and the content of SnO2 is 0-0.5mol%; Wherein, the RO is selected from at least one of MgO, SrO, BaO and ZnO; The content M1 of Y2O3, the content M2 of Pr2O3, the content M3 of RO, the content M4 of CaO, and the content M5 of Al2O3 satisfy formula (1) and formula (2): Formula (1): M2≤M1, and 1mol%≤M1+M2≤4mol%; Formula (2): M4>M3, and 1≤(M4+M3+1.5×(M1+M2)) / M5≤1.5; In the RO, based on the total mole of the composition, the content of MgO is 1-5 mol%, the content of SrO is 0-3 mol%, the content of BaO is 0-3 mol%, and the content of ZnO is 0-2 mol%.

2. The composition according to claim 1, characterized in that Based on the total mole of the composition, the content of SiO2 is 64-69mol%, the content of Al2O3 is 11-15mol%, the content of B2O3 is 4-7mol%, the content of CaO is 8-10mol%, the content of RO is 1-3mol%, the content of Y2O3 is 1-2mol%, the content of Pr2O3 is 0.5-2mol%, and the content of SnO2 is 0-0.5mol%.

3. The composition according to claim 1 or 2, characterized in that The content M1 of Y2O3 and the content M2 of Pr2O3 satisfy formula (3): Formula (3): M2≤M1, and 3mol%≤M1+M2≤4mol%.

4. The composition according to claim 1 or 2, characterized in that Based on the total mole of the composition, the content of SiO2 is 68.5-69 mol%, the content of Al2O3 is 11-12 mol%, the content of B2O3 is 6-7 mol%, the content of MgO is 1-2 mol%, the content of CaO is 8-9 mol%, the content of Y2O3 is 1-2 mol%, and the content of Pr2O3 is 1-2 mol%; The content M1 of Y2O3 and the content M2 of Pr2O3 satisfy formula (4): Formula (4): M2≤M1, 3.5mol%≤M1+M2≤4mol%.

5. A method for preparing a blue light filtering alkali-free glass substrate, characterized in that: The method comprises mixing the components in the composition for a blue light filtering alkali-free glass substrate according to any one of claims 1 to 4 and then sequentially performing melting treatment, molding treatment and annealing treatment.

6. A blue light filtering alkali-free glass substrate prepared by the method according to claim 5.

7. The blue light filtering alkali-free glass substrate according to claim 6, characterized in that: The glass substrate has the following properties: (1) The strain point is not less than 752°C; (2) Young’s modulus is not less than 82.4 GPa; (3) Annealing point is not less than 791°C; (4) The thermal expansion coefficient is 33×10 -7 -42×10 -7 / ℃; (5) Temperature T corresponding to a viscosity of 200 poise 200 ≤1611; (6) Density not higher than 2.7g / cm 3 .

8. The blue light filtering alkali-free glass substrate according to claim 6 or 7, characterized in that: The short-wave blue light transmittance T of the glass substrate (430-480nm) ≤5.6%.

9. Application of the blue light filtering alkali-free glass substrate according to any one of claims 6 to 8 in a display device; And / or, application of the blue light filtering alkali-free glass substrate in a TFT-LCD glass substrate and / or an OLED glass substrate.

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