| 摘要 |
Provided are a glass substrate for information recording media wherein air bubbles can be sufficiently removed, and an information recording medium using the glass substrate. The glass substrate contains 65 to 90 mass % of SiO2+Al2O3+B2O3 (where SiO2 is 45 to 75 mass %, Al2O3 is 1 to 20 mass %, and B2O3 is 0 to 8 mass %), 7 to 20 mass % of R2O (where R represents Li, Na, or K), 0.1 to 12 mass % of R′O (where R′ represents Mg, Ca, Sr, Ba, or Zn), and 0.5 to 10 mass % of TiO2+ZrO2. Moreover, the glass substrate contains at least one multivalent element selected from among a group consisting of V, Mn, Ni, Mo, Sn, Ce, and Bi; the molar ratio of the total amount of the oxide of the multivalent element to the total amount of TiO2+ZrO2 is within the range of 0.05 to 0.50. |
| 主权项 |
1. A glass substrate for information recording media, comprising, with respect to all components of the glass substrate:
45% to 75% by mass of SiO2; 1% to 20% by mass of Al2O3; and 0% to 8% by mass of B2O3, wherein a total amount of the SiO2, the Al2O3, and the B2O3 is 65% to 90% by mass;R2O, a total amount of which being 7% to 20% by mass
where: R represents Li, Na, or K; R′O, a total amount of which being 0.1% to 12% by mass where: R′ represents Mg, Ca, Sr, Ba, and Zn; TiO2; and optionally ZrO2, where TiO2 is an essential component, and a total amount of TiO2 and the optional ZrO2 is 0.5% to 10% by mass and the amount of TiO2 is 2.5% by mass or less, wherein the glass substrate for information recording media comprises at least one polyvalent element selected from a group consisting of V, Mn, Ni, Mo, Sn, Ce, and Bi, and wherein a mole ratio, which is (a total amount of an oxide of the polyvalent element)/(a total amount of the TiO2 and the ZrO2), of the total amount of the oxide of the polyvalent element with respect to the total amount of the TiO2 and the ZrO2 is in a range of 0.10 to 0.50, assuming each of oxides of polyvalent elements as V2O5, MnO2, Ni2O3, MoO3, SnO2, CeO2, and Bi2O3. |
