| 摘要 |
The invention relates to a glass substrate having a chemical composition substantially free from barium oxide and containing the following constituents within the following limits in weight percent: SiO2 60 to 68; B2O35 to 9; AI2O3 15 to 19; CaO 1 to 5; MgO 3 to 8; SrO 0 to 3; R2O 0 to 1, R2Oreferring to alkaline oxides; said glass substrate is characterised in that the CaO/MgO ratio is lower than or equal to 1.3. |
