| 摘要 |
PROBLEM TO BE SOLVED: To provide glass for an information recording medium substrate excellent in weatherability. SOLUTION: The glass for the information recording medium substrate contains, by mole on the following oxide basis, 58-78% of SiO<SB>2</SB>, 3-15% of Al<SB>2</SB>O<SB>3</SB>, 1-20% of Li<SB>2</SB>O, 0-16% of Na<SB>2</SB>O, 0-10% of K<SB>2</SB>O, 0-8% of MgO, 0-8% of CaO, 0-5% of ZrO<SB>2</SB>, and 0.02-0.2% of HfO<SB>2</SB>, wherein total content of Li<SB>2</SB>O, Na<SB>2</SB>O and K<SB>2</SB>O: Li<SB>2</SB>O+Na<SB>2</SB>O+K<SB>2</SB>O is 15-26%, and further contains no SrO or≤2% of SrO, no BaO or≤2% of BaO, and no TiO<SB>2</SB>or <1% of TiO<SB>2</SB>. COPYRIGHT: (C)2011,JPO&INPIT |
