Patent ID: 6713418
Filing Date: 2004-03-30
Classification: C03C

Abstract:
A glass article having:a rate of dissolution in an acidic liquid of from 20 to 60 nm/min in terms of an etching rate in immersing in a 0.1% by weight 50Â° C. aqueous solution of hydrofluoric acid; and an average linear thermal expansion coefficient of 70Ã—10âˆ’7/Â° C. or higher as measured in the range of from âˆ’50Â° C. to 70Â° C., in which a working temperature of the glass article: T4 Â° C. and a liquidus temperature of the glass article: TL Â° C. satisfy the relationship: T4âˆ’TL&gE;âˆ’100Â° C., and the glass article comprising: 60 to 68 mol % SiO2; 4 to 10 mol % Al2O3; 7 to 15 mol % Li2O; 8 to 20 mol % Na2O; 0 to 2 mol % K2O; 0.1 to 5 mol % MgO; 1 to 8 mol % CaO; 0 to 3 mol % SrO; 0 to 2 mol % BaO; 0 to 3 mol % TiO2; 0 to 3 mol % ZrO2; and 0 to 3 mol % other ingredient(s), wherein the sum of Li2O, Na2O and K2O is 18 to 35 mol % and the sum of MgO, CaO, SrO and BaO is 1.5 to 10 mol %.