초록 ▼

Magnetic disks comprising a substrate and glass materials which are used in the manufacture of hard disc substrates. The glasses can have the following compositions (in per cent by weight on an oxide basis): SiO.sub.2 10-30, Al.sub.2 O.sub.3 0-5, B.sub.2 O.sub.3 0-8, Li.sub.2 O 0-8, Na.sub.2 O 1-10,

Magnetic disks comprising a substrate and glass materials which are used in the manufacture of hard disc substrates. The glasses can have the following compositions (in per cent by weight on an oxide basis): SiO.sub.2 10-30, Al.sub.2 O.sub.3 0-5, B.sub.2 O.sub.3 0-8, Li.sub.2 O 0-8, Na.sub.2 O 1-10, with Li.sub.2 O+Na.sub.2 O 5-10, K.sub.2 O 0-3, MgO 5-16, CaO 0-15, with MgO+CaO>15-25, SrO+BaO 0-8, ZrO.sub.2 0-8, TiO.sub.2 7-25, La.sub.2 O.sub.3 0-10, Nb.sub.2 O.sub.5 5-20, V.sub.2 O.sub.5 0-10, CeO.sub.2 0-1, As.sub.2 O.sub.3 +Sb.sub.2 O.sub.3 +F 0.1-1. These glasses can have high dimensional stability as a result of their high specific modulus of elasticity, to be especially suited for hard disk substrates.

대표청구항

[ What is claimed is:] [1.]1. A magnetic disk comprising a substrate, said substrate comprising a glass having the following composition (in per cent by weight on an oxide basis):TBL

[ What is claimed is:] [1.]1. A magnetic disk comprising a substrate, said substrate comprising a glass having the following composition (in per cent by weight on an oxide basis):TBL