| 摘要 |
PROBLEM TO BE SOLVED: To provide glass for magnetic recording medium substrates which shows excellent chemical durability and has an extremely smooth surface.SOLUTION: The glass for magnetic recording medium substrate comprises, expressed in mol% on an oxide basis, comprises SiO: 60-75%, AlO: 1-15%, LiO: 0.1-20%, NaO: 0.1-15%, and KO: 0-5% (where a total content of LiO, NaO and KO is 25% or less), and also comprises a total content of 0.1-3.5 mass% of Sn oxide and Ce oxide relative to the total mass, where a ratio of the content of Sn oxide to the total content of 0.1-3.5 mass% of Sn oxide and Ce oxide (Sn oxide content/(Sn oxide content + Ce oxide content)) is 0.45-0.85, and the content of Sb oxide is 0-0.1%. The glass is free from As and F.SELECTED DRAWING: None |
