| 摘要 |
<p>The present invention provides suitable for high density recording, is not easily broken glass substrate. The glass for substrate of the present invention contains, at mol% based on the following oxides: 66% to 77% of SiO2, 7% to 17% of Al2O3, 0 to 7% of B2O3, 0-9% of Li2O, 0-8% of Na2O, 0-3% of K2O, 0-13% of MgO, 0-6% of CaO, 0-5% of TiO2, 0-5% of ZrO2, a content sum of SiO2, Al2O3 and B2O3, SiO2 + Al2O3 + B2O3 is 81%-92%, the content sum of Li2O, Na2O and K2O, Li2O + Na2O + K2O is 3%-9%, a content sum of MgO and CaO, MgO + of CaO, is 4%-13% , a content sum of Na2O, K2O and CaO, Na2O + K2O + of CaO is 0-10%, and a content sum of TiO2 and ZrO2, TiO2 + ZrO2, is 0-5%.</p> |
