| 摘要 |
PURPOSE:To improve durability and corrosion resistance by incorporating a specific metal oxide into protective layers. CONSTITUTION:This recording medium has a thin magnetic film layer 4 as a recording layer on a substrate 2 and the protective layers 31, 35 respectively consisting of a glassy material are provided on the rear and front faces of the layer 4. The protective layers are so formed that said layers contain silicon oxide, boron oxide, aluminum oxide, alkali metal oxide and metal oxide expressed by RO (R is a bivalent metal element) and that the content of the silicon oxide is 40-60wt% and the content of the alkali metal oxide 0.5-10wt%. The protective layers are formed preferably to 300-3,000Angstrom , more preferably to 500-2,000Angstrom thickness. The deterioration of the recording layer 4 is thereby prevented and the optical recording medium having the excellent corrosion resistance and durability is obtd. |
