Glass composition, high performance electronic glass substrate and method of making the same

Abstract

The application discloses a glass composition, a high-performance electronic glass substrate and a preparation method thereof, and belongs to the technical field of glass materials. The glass composition comprises the following components in terms of molar percentage of oxides: SiO2 63-65mol%, Al2O3 15-18mol%, B2O3 0.5-1.5mol%, alkaline earth metal oxide RO 10-16.5mol%, SnO2 0.08-0.2mol%, alkaline earth metal fluoride RF2 1.0-1.5mol%, P2O5 0.2-3mol%, rare earth oxide R'2O3 0.2-5mol%. The application can overcome the problems of difficult melting and forming while keeping the strain point of the glass greater than or equal to 750 DEG C and the thermal expansion coefficient in the range of 32*10 ‑7 -40*10 ‑7 .

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of glass materials, in particular to a glass composition, a high-performance electronic glass substrate and a preparation method thereof. BACKGROUND

[0002] With the progress of science and technology, electronic information display technology has been upgraded from traditional CRT (Cathode Ray Tube) to TFT-LCD (Thin Film Transistor Liquid Crystal Display), and further upgraded to OLED display technology (Organic Electroluminescence Display) in recent years. OLED display technology has many advantages such as simpler structure, thinner overall device thickness, lower weight, higher resolution, more saturated display color, faster response speed, and lower panel power consumption, so this display technology has gradually replaced TFT-LCD technology and become the new mainstream in recent years.

[0003] The glass substrate is the base of the panel electronic device, and there are many process technologies on it. Compared with TFT-LCD display technology, the process temperature of OLED display technology is higher. In order to ensure that the glass substrate does not deform significantly during the process, the strain point of the glass is strictly limited, and it is usually required to be at least greater than 730℃. However, in the prior art, the glass becomes difficult to melt when the strain point is increased, which increases the viscosity of the glass melt and makes it difficult to discharge bubbles, which increases the difficulty of the forming process and also increases the energy consumption. In addition, the glass substrate has other strict requirements, such as higher Young's modulus, lower defect rate, higher strain point, lower density, appropriate thermal expansion coefficient, better chemical durability, etc.

[0004] The Chinese patent document with publication number CN116102254A discloses an OLED glass substrate composition composed of the following raw materials in mass percentage: SiO2 61-63%, Al2O3 17-20%, CaO 4-8%, B2O3 0.5-2%, MgO 3-6%, SrO 0-4%, BaO 2-8%, SnO2 0.15-0.3%, Sr(NO3)2 0.07%-0.8%. In this invention, the key raw material is SiO2+Al2O3 80-82%, which determines the tightness of the glass network structure and plays a role in enhancing the strength of the glass. The OLED glass substrate prepared by this invention has a strain point as high as 720℃ or above, and an elastic modulus of 80GPa or above.

[0005] The Chinese patent document with the publication number CN105731790A discloses a composition for alkali-free alumino-silicate glass, which contains, in terms of oxides, 63-72wt% of SiO2, 15-20wt% of Al2O3, 4-10wt% of MgO, 2-6wt% of CaO, 0.01-2.5wt% of SrO, 2-8wt% of BaO, 0.1-1.5wt% of In2O3 and 0.1-0.3wt% of SnO2. The glass prepared from the composition has a high strain point, a low melting temperature, a low expansion coefficient, high chemical stability and mechanical properties, a high Young's modulus, a high transmittance, a low density and the like, and is particularly suitable for OLED glass substrates. SUMMARY

[0006] The present application provides a glass composition, by reasonably configuring the raw material component range, the strain point of the glass is ≥750℃, the thermal expansion coefficient is in the range of 32×10 -7 ~40×10 -7 , while overcoming the problems of difficult melting and molding.

[0007] The specific technical solutions are as follows:

[0008] A glass composition, the composition contains, in terms of oxide mole percentage, SiO2 63-65mol%, Al2O3 15-18mol%, B2O3 0.5-1.5mol%, alkaline earth metal oxide RO 10-16.5mol%, SnO2 0.08-0.2mol%, alkaline earth metal fluoride RF2 1.0-1.5mol%, P2O5 0.2-3mol%, and rare earth oxide R’2O3 0.2-5mol%;

[0009] The alkaline earth metal oxide RO includes MgO and SrO, and the mole percentage of MgO is 12-14mol%; R’2O3 includes at least one of Y2O3 or La2O3;

[0010] The total proportion M1 of the alkaline earth metal oxide RO and the alkaline earth metal fluoride RF2, the proportion M3 of Al2O3, and the proportion M4 of B2O3 satisfy the condition: M3+M4>M1.

[0011] In the formula of the present application, on the one hand, the proportion of alkaline earth metal oxides is regulated, so that magnesium oxide is the main component of alkaline earth metal oxides, which is conducive to enhancing the network agglomeration effect, increasing the glass network polymerization degree, thereby improving the strain point and reducing the thermal expansion coefficient; on the other hand, compared with other formulas, phosphorus pentoxide and rare earth metal oxides are introduced, which can accelerate melting and reduce high-temperature viscosity. At the same time, the content of network intermediates (aluminum oxide, boron oxide) in the component is slightly greater than the content of alkaline earth metal oxides and alkaline earth metal fluorides, and the excess network intermediates can combine with phosphorus pentoxide or rare earth metals to enter the three-dimensional network, thereby avoiding or reducing the side effects of simply adding rare earth oxides or phosphorus pentoxide on the strain point.

[0012] Optionally, the RO further includes CaO. Compared with other alkaline earth metal oxides, CaO has a shorter material property, which can accelerate the hardening speed of the glass and accelerate the forming efficiency.

[0013] Preferably, the glass composition contains, in terms of molar percentage of oxides: SiO263.5-64.5mol%, Al2O316-17mol%, B2O31.0-1.5mol%, MgO 12-14mol%, SrO 0.2-0.5mol%, CaO 0-2mol%, SnO20.1-0.2mol%, MgF21.0-1.5mol%, P2O50.2-2mol%, Y2O30-3mol%, La2O30-2mol%; Y2O3 and La2O3 are not both 0.

[0014] Preferably, the composition contains, in terms of molar percentage of oxides, the proportion of rare earth oxides R’2O3 M2, and the proportion of P2O5 M5, which satisfy the condition:

[0015] 1mol%≤M2+M5≤4mol%;

[0016] and when M2≥1.5mol%, M5≤1mol%, or when M5≥2mol%, M2≤1mol%. Further preferably, M3+M4-3 mol%≤M1+M2≤M3+M4+1mol%; and / or;

[0017] M3+M4-1 mol%≤M1+M2+M5≤M3+M4+2mol%.

[0018] The present application also provides a preparation method of a high-performance electronic glass substrate, comprising: mixing dry raw materials in proportion, melting, forming, and annealing to obtain the high-performance electronic glass substrate, wherein the raw materials include compounds capable of being introduced into the glass composition.

[0019] Preferably, the raw materials include quartz sand, aluminum hydroxide, boric anhydride, magnesium oxide, calcium carbonate, strontium carbonate, ammonium dihydrogen phosphate, yttrium oxide, lanthanum oxide, magnesium fluoride or tin dioxide, etc.

[0020] Preferably, the melting temperature is 1550-1650 DEG C, the holding time is 2-4 h, the annealing temperature is 750-900 DEG C, and the holding time is 2-2.5 h.

[0021] The application further provides a high-performance electronic glass substrate prepared by the method.

[0022] Preferably, the high-performance electronic glass substrate has a strain point of greater than or equal to 750 DEG C, a thermal expansion coefficient of 32*10 -7 -40*10 -7 , a Vickers hardness of greater than 690 Hv, and a viscosity of 200 poise corresponding to a temperature T 200 <1500 DEG C.

[0023] The application further provides the use of the glass composition or the high-performance electronic glass substrate in photovoltaic display devices, building glass, etc.

[0024] Compared with the prior art, the application has the following beneficial effects:

[0025] (1) The high-performance electronic glass substrate provided by the application has a strain point of greater than or equal to 750 DEG C, a thermal expansion coefficient of 32*10 -7 -40*10 -7 , a Vickers hardness of greater than 690 Hv, and a viscosity of 200 poise corresponding to a temperature T 200 <1500 DEG C.

[0026] (2) The introduction of fluorides can reduce the high-temperature viscosity of the glass, but excessive introduction can easily lead to glass opalescence; the introduction of rare earth oxides can provide free oxygen while maintaining a high strain point, but excessive introduction can easily lead to a significant increase in density; the introduction of phosphorus pentoxide has a fluxing effect, but excessive introduction can lead to a change in the glass network structure to a phosphate network, which reduces the aggregation degree of the glass network and lowers the strain point. In the technical solution of the application, the amounts of fluorides, rare earth oxides and phosphorus pentoxide are controlled to avoid or reduce their negative effects, and the network intermediates (aluminum oxide and boron oxide) in the components are slightly excessive, which not only can capture free oxygen and combine with alkaline earth metals or rare earths, but also can combine with phosphorus pentoxide at high temperatures to break the phosphorus-oxygen double bond of phosphorus oxide, so that phosphorus oxide enters the silicon-oxygen three-dimensional network, thereby reducing the depolymerization effect of phosphorus pentoxide on the network and maintaining a high strain point of the glass.

[0027] (3) Due to the design of specific raw materials and raw material content (such as MgF2, SnO2, SrCO3, etc.), the progress of silicate reaction and high-temperature refining effect in the preparation process of high-performance electronic glass substrate are promoted, and the glass homogenization is good, and the refining effect is good. DETAILED DESCRIPTION

[0028] The application will be further illustrated below with examples. It should be understood that the examples are only used to illustrate the application, and are not used to limit the scope of the application.

[0029] A glass composition, the composition is in terms of molar percentage of oxide, contains: SiO2 63-65 mol%, Al2O3 15-18 mol%, B2O3 0.5-1.5 mol%, alkaline earth metal oxide RO 10-16.5 mol%, SnO2 0.08-0.2 mol%, alkaline earth metal fluoride RF2 1.0-1.5 mol%, P2O5 0.2-3 mol%, rare earth oxide R’2O3 0.2-5 mol%;

[0030] Among them, the alkaline earth metal oxide RO includes MgO and SrO, and the molar percentage of MgO is 12-14 mol%; R’2O3 includes at least one of Y2O3 or La2O3;

[0031] The total proportion M1 of the alkaline earth metal oxide RO and the alkaline earth metal fluoride RF2, the proportion M3 of Al2O3, and the proportion M4 of B2O3 satisfy the condition: M3+M4>M1.

[0032] Aluminum oxide and boron oxide both have a certain effect of taking free oxygen, thereby combining with alkaline earth metal or with rare earth.

[0033] The above scheme can achieve the purpose of the application, and the preferred scheme is given on this basis:

[0034] As preferred, the glass composition, the composition is in terms of molar percentage of oxide, contains: SiO2 63.5-64.5 mol%, Al2O3 16-17 mol%, B2O3 1.0-1.5 mol%, MgO 12-14 mol%, SrO 0.2-0.5 mol%, CaO 0-2 mol%, SnO2 0.1-0.2 mol%, MgF2 1.0-1.5 mol%, P2O5 0.2-2 mol%, Y2O3 0-3 mol%, La2O3 0-2 mol%; Y2O3 and La2O3 are not 0 at the same time.

[0035] It should be noted that:

[0036] SiO2 is the network former of glass, and is the main skeleton of silicate glass which constitutes a three-dimensional network. SiO2 can improve the thermal stability, chemical stability, hardness, mechanical strength and other properties of the glass, and also can reduce the thermal expansion coefficient of the glass, which is beneficial to the glass substrate. However, when the content is too high, the glass becomes difficult to melt, and the crystallization tendency becomes large, which is not conducive to production. In the present application, the content of SiO2 is preferably in the range of 63.5-64.5 mol%.

[0037] Al2O3 is the network intermediate of glass, and Al2O3 can capture the free oxygen of alkaline earth metal oxides and other network modifiers, so that itself enters the three-dimensional network of glass as a four-coordinated state. In the present application, the addition of Al2O3 can reduce the crystallization tendency of the glass, and at the same time improve the chemical stability, thermal stability, hardness, mechanical strength and other properties of the glass, and also can reduce the corrosion of the glass to refractory materials. In the present application, the content of Al2O3 is preferably in the range of 16-17 mol%.

[0038] B2O3 is a fluxing agent of glass, and is also a network intermediate, which can improve the melting speed, reduce the melting energy consumption, and also can reduce the high temperature viscosity of the glass. However, in the glass substrate, B2O3 mainly exists in the form of [BO3] triangle, and cannot form a complete three-dimensional network, so it is not conducive to network aggregation, and has an adverse effect on the strain point at high content. In the present application, the content of B2O3 is preferably in the range of 1.0-1.5 mol%.

[0039] MgO is an alkaline earth metal oxide, and all alkaline earth metals belong to network outsiders. In the glass substrate, MgO provides free oxygen, so that aluminum or boron becomes four-coordinated to enter the three-dimensional network structure, and at the same time reduces the high temperature viscosity of the glass. Compared with other alkaline earth metal oxides, MgO has the effect of prolonging the glass flowability and reducing the glass hardening speed, and Mg has a higher field strength than other alkaline earth metals. When Mg exists as a modifier in the network gap, it has the effect of aggregating the nearby network, which can to some extent, aggregate the network. In the present application, MgO is used as the main component of alkaline earth metal oxide, and the content range is preferably 12-14 mol%.

[0040] SrO is an alkaline earth metal oxide, and the raw material for introducing SrO is mainly strontium carbonate. A small amount of strontium carbonate has a certain clarifying effect. In addition, SrO can absorb X-rays, and can reduce the radiation of the display screen. In the present application, the content of SrO is preferably in the range of 0.2-0.5 mol%.

[0041] CaO is an alkaline earth metal oxide, and compared with other alkaline earth metals, it has shorter flowability, which can accelerate the hardening speed of the glass. In the present application, the content of CaO is preferably in the range of 0-2 mol%.

[0042] SnO2 is a network former, which is a commonly used fining agent. Appropriate addition of SnO2 helps to eliminate bubbles in the glass, but excessive addition of SnO2 can easily lead to glass opalescence. In the present application, the content of SnO2 is preferably in the range of 0.1-0.2 mol%.

[0043] MgF2 is a fining agent and a fluxing agent. In terms of fining, MgF2 has the effects of reducing the viscosity of the glass liquid and reducing the surface tension of the melt, thereby promoting the discharge of bubbles in the melt, achieving the effect of auxiliary clarification; in terms of fluxing, MgF2 has the effect of accelerating the melting efficiency. In addition, the introduction of a certain amount of F element can also replace harmful impurities such as FeO / Fe2O3 into FeF3 volatilization during the melting stage, which helps to reduce glass impurities. Excessive F element content can easily lead to an increase in the tendency of glass crystallization and cause glass opalescence. In the present application, the content of MgF2 is preferably in the range of 1.0-1.5 mol%.

[0044] P2O5 is a network former, which mainly exists in the form of four coordination in glass, but since phosphorus is +5 valence, one of the coordination is a phosphorus-oxygen double bond, which cannot participate in network connection, so the structure of P2O5 is similar to [BO3] unit, which is a layered or chain network, and cannot enter the three-dimensional network structure, which is not conducive to the integrity of the network. In traditional LCD glass substrates, P2O5 is mainly used for fluxing and reducing high-temperature viscosity, similar to B2O3. The inventors of the present application have found through research that in the environment of high network intermediates (aluminum oxide, boron oxide), especially when the sum of the mole percentages of Al2O3 and B2O3 is greater than the sum of the mole percentages of RO and RF2, the addition of a small amount of P2O5 can make part of the network intermediates preferentially combine with phosphorus oxide, open the phosphorus-oxygen double bond of phosphorus oxide, and make the phosphorus-oxygen form a tetrahedron into a three-dimensional network. The use of a small amount of this structure to replace the silicon-oxygen network can reduce the high-temperature viscosity to a certain extent without significantly reducing the strain point. In the present application, the content of P2O5 is preferably in the range of 0.2-2 mol%.

[0045] Y2O3 is a rare earth oxide, which is a network modifier. Compared with alkaline earth metal oxides, Y2O3 has the ability to reduce the viscosity of glass, but does not reduce the strain point of glass, and can improve the Young's modulus, which has a good improvement effect on the performance of glass substrates. However, excessive Y2O3 content can also significantly increase the density of glass, which is not conducive to production. In the present application, the content of Y2O3 is preferably in the range of 0-3 mol%.

[0046] La2O3 is a rare earth oxide, which has similar effects as Y2O3. Because of its large ionic radius, La2O3 has a high coordination number when in the network gap, which can make the glass structure more compact, and due to its high field strength, it can form a clustering effect similar to MgO. A high content of La2O3 can also significantly increase the density. In the present application, the content of La2O3 is preferably in the range of 0-2 mol%.

[0047] Preferably, the total content of alkali earth metal oxide RO and alkali earth metal fluoride RF2, the content of rare earth oxide R’2O3, the content of Al2O3, the content of B2O3, and the content of P2O5, in terms of mole percentage of oxides, satisfy the condition:

[0048] 1 mol%≤M2+M5≤4 mol%, and when M2≥1.5 mol%, M5≤1 mol%; or when M5≥2 mol%, M2≤1 mol%; the content of P2O5 and rare earth oxide cannot be too high at the same time, otherwise the strain point will be excessively reduced, and the thermal expansion coefficient will deviate from the appropriate range. Under the above preferred conditions, it is more beneficial to reduce the high-temperature viscosity.

[0049] Further preferably, M3+M4-3 mol%≤M1+M2≤M3+M4+1 mol%; in the composition of the present application, the main free oxygen provider is the alkali earth metal oxide and the rare earth oxide, and when the above range is satisfied, it is beneficial for Al and B in the glass to exist in the form of four-coordination, ensuring that the network will not be depolymerized and thus reducing the low-temperature characteristic viscosity of the glass.

[0050] and / or; M3+M4-1 mol%≤M1+M2+M5≤M3+M4+2 mol%; under the above conditions, the integrity of the network can be ensured, and the effect of high-temperature viscosity can be achieved.

[0051] The present application is described in detail below through Examples 1-5:

[0052] In the following examples and comparative examples, the glass raw materials used are selected from quartz sand, aluminum hydroxide, boric anhydride, magnesium oxide, calcium carbonate, strontium carbonate, ammonium dihydrogen phosphate, yttrium oxide, lanthanum oxide, magnesium fluoride, and tin dioxide; specifically, the dry raw materials are mixed uniformly in proportion, melted at 1650°C for 3h to obtain a melt, poured into a preheated mold at 400°C to form, hardened, and then annealed at 800°C for 2h. After cutting and polishing, an electronic glass substrate is obtained. Specifically, the glass raw material proportions are converted according to the mole fractions provided in Table 1 and then weighed.

[0053] Table 1 Glass composition components in Examples 1-5 and Comparative Example 1 (in terms of mole percentage of oxides)

[0054]

[0055] The properties of the electronic glass substrates obtained in the test examples were tested, specifically, hardness test was performed using a Vickers hardness tester, high temperature viscosity test was performed using a high temperature viscometer, strain point and thermal expansion coefficient test was performed using a thermal dilatometer, and the results are shown in Table 2:

[0056] Table 2 Test results of the properties of the electronic glass substrates obtained in Examples 1-5 and Comparative Example 1

[0057]

[0058] As can be seen from the results in Table 2, the high-performance electronic glass substrate of the present application has a low high-temperature viscosity while maintaining a glass strain point ≥ 750℃ and a thermal expansion coefficient in the range of 32×10 -7 ~ 40×10 -7 -6, which is difficult to measure the high-temperature viscosity of the high-phosphorus component, but the high-temperature viscosity is low as observed by the naked eye, can reduce the difficulty of the forming process to some extent, significantly reduces the high-temperature viscosity compared to Comparative Document 1, and has excellent performance.

[0059] The above-described examples have described the technical solutions of the present application in detail, and it should be understood that the above-described is only a specific embodiment of the present application and is not intended to limit the present application. Any modification, supplement or similar replacement within the principle range of the present application should be included in the protection scope of the present application.

Claims

1. A glass composition characterized in that, comprises, in terms of mole percentage of oxides: SiO2 63-65 mol%, Al2O3 15-18 mol%, B2O3 0.5-1.5 mol%, alkaline earth metal oxide RO 10-16.5 mol%, SnO2 0.08-0.2 mol%, alkaline earth metal fluoride RF2 1.0-1.5 mol%, P2O5 0.2-3 mol%, rare earth oxide R'2O3 0.2-5 mol%; wherein the alkaline earth metal oxide RO comprises MgO and SrO, and the mole percentage of MgO is 12-14 mol%; R'2O3 comprises at least one of Y2O3 or La2O3; the total mole percentage of the alkaline earth metal oxide RO and the alkaline earth metal fluoride RF2 is M1, the mole percentage of Al2O3 is M3, and the mole percentage of B2O3 is M4, which satisfy the condition: M3+M4>M1; the mole percentage of the rare earth oxide R'2O3 is M2, and the mole percentage of P2O5 is M5, which satisfy the condition: 1 mol%≤M2+M5≤4 mol%; and when M2≥1.5 mol%, M5≤1 mol%, or when M5≥2 mol%, M2≤1 mol%.

2. The glass composition of claim 1, wherein, The RO further comprises CaO.

3. The glass composition of claim 1, wherein, comprises, in terms of mole percentage of oxides: SiO2 63.5-64.5 mol%, Al2O3 16-17 mol%, B2O3 1.0-1.5 mol%, MgO 12-14 mol%, SrO 0.2-0.5 mol%, CaO 0-2 mol%, SnO2 0.1-0.2 mol%, MgF2 1.0-1.5 mol%, P2O5 0.2-2 mol%, Y2O3 0-3 mol%, La2O3 0-2 mol%; Y2O3 and La2O3 are not both 0.

4. The glass composition of claim 3, wherein, comprises, in terms of mole percentage of oxides: M3+M4-3 mol%≤M1+M2≤M3+M4+1 mol%; and / or; M3+M4-1 mol%≤M1+M2+M5≤M3+M4+2 mol%.

5. A method of producing a high performance electronic glass substrate, characterized by, comprises: mixing dry raw materials in a proportion to obtain the high-performance electronic glass substrate, wherein the raw materials comprise compounds capable of introducing the glass composition according to any one of claims 1-4.

6. The method of making high performance electronic glass substrates according to claim 5, wherein, The melting temperature is 1550-1650°C, and the holding time is 2-4 h; the annealing temperature is 750-900°C, and the holding time is 2-2.5 h.

7. The high-performance electronic glass substrate prepared by the method according to claim 5 or 6.

8. The high performance electronic glass substrate according to claim 7, wherein, The high-performance electronic glass substrate has a strain point ≥750℃ and a coefficient of thermal expansion of 32×10⁻⁶. -7 ~40×10 -7 Vickers hardness > 690 Hv, viscosity 200 poise at corresponding temperature T 200 <1500℃.

9. The glass composition according to any one of claims 1 to 4 or use of the high- performance electronic glass substrate according to claim 7 or 8, characterized in that The glass composition or the high-performance electronic glass substrate is used in a photovoltaic display device or a building glass.

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