| 发明名称 |
GLASS FOR MAGNETIC RECORDING MEDIUM SUBSTRATE AND USAGE THEREOF |
| 摘要 |
An aspect of the present invention relates to glass for a magnetic recording medium substrate, which includes essential components in the form of SiO2, Li2O, Na2O, and one or more alkaline earth metal oxides selected from the group consisting of MgO, CaO, SrO, and BaO, wherein a molar ratio of a content of MgO to a combined content of MgO, CaO, SrO, and BaO (MgO/(MgO+CaO+SrO+BaO)) is equal to or greater than 0.80, and which has a Young's modulus of equal to or greater than 80 GPa, and a glass transition temperature of equal to or greater than 620° C. |
| 申请公布号 |
US2014334276(A1) |
申请公布日期 |
2014.11.13 |
| 申请号 |
US201414341142 |
申请日期 |
2014.07.25 |
| 申请人 |
Hoya Corporation |
发明人 |
MATSUMOTO Naomi;Hashimoto Kazuaki |
| 分类号 |
G11B5/73;C03C3/087;C03C3/085 |
主分类号 |
G11B5/73 |
| 代理机构 |
|
代理人 |
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| 主权项 |
1. Glass for a magnetic recording medium substrate, which comprises:
essential components in the form of SiO2, Li2O, Na2O, and one or more alkaline earth metal oxides selected from the group consisting of MgO, CaO, SrO, and BaO; wherein a molar ratio of a content of MgO to a combined content of MgO, CaO, SrO, and BaO (MgO/(MgO+CaO+SrO+BaO)) is equal to or greater than 0.80; and which has a glass transition temperature of equal to or greater than 620° C., and wherein a specific modulus of elasticity is equal to or greater than 30 MNm/kg. |
| 地址 |
Tokyo JP |
