| 摘要 |
PROBLEM TO BE SOLVED: To provide a glass for information recording medium substrate excellent in acid resistance and weather resistance.SOLUTION: There is provided a glass for information recording medium substrate containing SiOof 61 to 72%, AlOof 5.5 to 12%, LiO of 0 to 4%, NaO of 0 to 13%, KO of 0 to 22%, MgO of 4 to 13%, CaO of over 2% and 8% or less, TiOof 0 to 6%, ZrOof 0.5 to 5% and having total content RO of LiO, NaO and KO of 8 to 22%, satisfying a plurality of conditions of (1) to (3), (1) a ratio of the content of LiO and RO, LiO/RO of 0.52 or less, (2) a ratio of the content of NaO and RO, NaO/RO of 0.35 or more and (3) a ratio of the content of KO and RO, KO/RO of 0.45 or more, containing no BOor less than 1% of BOand having Young modulus of 75 GPa or more and specific modulus of 28 MNm/kg or more and specific function Cof 12 nmol/cmor less.SELECTED DRAWING: Figure 1 |
