Silica-soda-lime glass compositions and their applications

摘要

The invention relates to a glass composition intended for the manufacture of thermally stable substrates or panes, which comprises the following constituents in the following proportions by weight: - SiO2 55-70% - Al2O3 0-5% or 5-10% - ZrO2 5-10% or 0-5% - B2O3 0-3% - Na2O 2-6% - K2O 5-11% - MgO 0-6% - CaO 2-11% - SrO 4-12% - BaO 0-2% - with the following relationships: Na2O+K2O>/=8% MgO+CaO+SrO+BaO>10% the said composition having a strain point which is in excess of 600 DEG C.