GLASS FOR SUBSTRATE OF INFORMATION RECORDING MEDIUM AND GLASS SUBSTRATE FOR INFORMATION RECORDING MEDIUM USING SAME

摘要

PROBLEM TO BE SOLVED: To obtain a glass for a glass substrate excellent in meltability and having a higher Young's modulus without requiring an ion exchange step. SOLUTION: This glass for the substrate of an information recording medium contains, by mol, 25-45% SiO2, 25-45% TiO2, 20-35% RO, 0-10% Al2O3 and 0-8% ZrO2 (Al2O3+ZrO2<=15%). Since an alkali metal is not contained, ion exchange treatment is not required. The glass is excellent in meltability and has a high Young's modulus because of 25-45% TiO2 content.