| 摘要 |
PROBLEM TO BE SOLVED: To obtain a glass substrate for an information-recording medium and a magnetic recording medium using the glass substrate which enables a magnetic head or the like to levitate low and run smoothly, has a large specific modulus of elasticity and superior strength, is hard to warp or vibration even when the medium rotates at high speeds, can sufficiently cope with thinning of a substrate, and never loses transparency. SOLUTION: A glass generating surface projections of a not melted component of a raw material of 7μm or smaller height, e.g. ZrO2 or the like is used to constitute a substrate. An aluminosilicate glass containing 0.6-1.9mol.% ZrO2 and 6-14mol.% Li2 O is used as the glass constituting the substrate. Further, an aluminosilicate glass containing TiO2 , specifically, a chemical reinforcement glass containing 0.2-3.0mol.% TiO2 , 2.8mol.% or smaller ZrO2 and 0.9mol.% or smaller B2 O3 is used. |
