Alkaline-Earth Aluminosilicate Glass Composition for High Strain Point
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Solution Overview
Problem
The challenge in glass manufacturing for flat panel displays is to achieve a glass substrate with a high strain point, high chemical stability, and low thermal expansion coefficient while minimizing production costs and environmental impact, particularly in the context of alkali-free glass substrates that do not use toxic fining agents like As2O3 and Sb2O3.
Innovation Solution
A composition of alkaline-earth aluminosilicate glass with specific mole percentages of SiO2, Al2O3, MgO, CaO, SrO, BaO, ZnO, and TiO2, along with a non-toxic fining agent such as stannous oxide, is used to create a glass substrate with improved mechanical and thermal properties, such as higher Young's modulus, specific modulus, and chemical stability, without the use of toxic fining agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the content of glass formers (SiO2, Al2O3) is increased to improve strain point, then the strain point increases, but the melting and fining becomes difficult, energy consumption increases, and production costs increase
Solution Approach 1:
The patent changes the chemical composition parameters by introducing specific amounts of B2O3 (0.1-5.0 wt%) and ZnO (0.1-3.0 wt%) into the glass system. These compositional modifications alter the melting behavior and viscosity characteristics, enabling the glass to achieve high strain point (≥670°C) while maintaining easier melting and fining properties with reduced energy consumption.
2Temperature
If the content of glass formers is increased to improve strain point, then the strain point increases, but the liquidus temperature increases and the probability of solid defects increases, compromising glass formation stability
Solution Approach 1:
The patent creates a composite glass system combining SiO2-Al2O3 base glass with B2O3-ZnO modifiers. This composite composition achieves a balance where the SiO2-Al2O3 matrix provides high strain point, while B2O3 and ZnO components lower the liquidus temperature and reduce solid defect formation, thereby improving overall glass formation stability.
3Reliability
If B2O3 is added to improve chemical resistance and melting acceleration, then chemical resistance improves, but the strain point severely decreases
Solution Approach 1:
The patent precisely controls the B2O3 content within 0.1-5.0 wt% and combines it with ZnO (0.1-3.0 wt%). This parameter optimization ensures that the chemical resistance enhancement from B2O3 is achieved while the strain point reduction is minimized through the synergistic effect of ZnO and the controlled composition ratio.
4Weight of moving object
If the glass substrate is made thinner to reduce weight, then weight decreases, but the sag of the glass substrate increases due to self-weight
Solution Approach 1:
The patent modifies the glass composition to achieve specific physical property ranges: density of 2.40-2.60 g/cm³ and elastic modulus of 70-80 GPa. This parameter optimization allows thin glass substrates to maintain sufficient mechanical strength and resistance to sagging under self-weight, enabling weight reduction without excessive deformation.
Data Source
AI summary
The present invention discloses a composition for glass, an alkaline-earth aluminosilicate glass, a preparation method and an application thereof. Based on the total number of moles of the components, on an oxide basis, the composition contains 68-73 mol% SiO2, 11.5-15 mol% Al2O3, 2-6 mol% MgO, 2.5-7.5 mol% CaO, 0-3 mol% SrO, 2-7 mol% BaO, 0-4 mol% ZnO, and 0.05-1.5 mol% TiO2. The glass has higher strain point, higher Young's modulus, higher specific modulus, higher Vickers hardness, higher chemical stability, higher refractivity, higher stability of glass formation, lower forming temperature, lower melting temperature, lower thermal expansion coefficient, lower surface tension, lower density, and lower glass manufacturing difficulty.