Patent ID: 8652659
Filing Date: 2014-02-18
Classification: C03C,G11B

Abstract:
1. A glass substrate for an information recording medium made of aluminosilicate glass containing 60% to 75% by mass of SiO 2 , 5% to 18% by mass of Al 2 O 3 , 3% to 10% by mass of Li 2 O, 3% to 15% by mass of Na 2 O, and 0.5% to 8% by mass of ZrO 2 with respect to whole glass components, and containing neither As (arsenic) element nor Sb (antimony) element, comprising: a fining agent containing SO wherein a total content of the fining agent is in a range of 1% by mass or less with respect to the whole glass components.