Patent ID: 6333286
Filing Date: 2001-12-25
Classification: C03C,G11B

Abstract:
A glass composition consisting of the following components, in terms of mol %:55 to 65% SiO.sub.2,0.5 to less than 6% Al.sub.2 O.sub.3,12 to 22% Li.sub.2 O,0 to 5% Na.sub.2 O,0 to 10% TiO.sub.2,0 to 3% ZrO.sub.2,O to 8% MgO,0 to 18% CaO, and0 to 6% SrO,provided that the content of RO (RO=MgO+CaO+SrO) is 5 to 18% and at least one of As.sub.2 O.sub.3, Sb.sub.2 O.sub.3, SO.sub.3, SnO.sub.2, Fe.sub.2 O.sub.3, CoO, Cl, F, K.sub.2 O, and Y.sub.2 O.sub.3 is amount of up to 3 mol %, and wherein the proportion of Na.sub.2 O to Li.sub.2 O is in the range of from 1/1 to 1/5 and that of MgO to CaO is in the range of from 1/4 to 1/1.