Patent ID: 8119268

Claim:
An information recording media, comprising glass substrate for a magnetic disk and a magnetic recording layer formed thereon, wherein said glass substrate comprises, as represented by mol % based on oxide: from 61 to 66% of SiO 2 , from 11.5 to 17% of Al 2 O 3 , from 8 to 16% of Li 2 O, from 2 to 8% of Na 2 O, from 2.5 to 8% of K 2 O, from 0 to 6% of MgO, from 0 to 4% of TiO 2 , from 0 to 3% of ZrO 2 , and from 0 to 1% of at least one alkaline earth metal oxide selected from the group consisting of CaO, SrO and BaO; provided that Al 2 O 3 +MgO+TiO 2 at least 12%, and Li 2 O+Na 2 O+K 2 O is from 16 to 23%, and said glass comprises less than 1% of B 2 O 3 .