Glass constituent null for grace formation

摘要

PURPOSE:To obtain a glass composition, consisting of SiO2, Al2O3, CaO, BaO, MgO, SrO, TiO2, ZrO2, SnO2, B2O3, ZnO and F+SO3+As2O5+Sb2O5+V2O5 and capable of providing a glaze layer having a small end meniscus and excellent surface smoothness, heat resistance and mechanical strength. CONSTITUTION:Respective raw materials are mixed so as to provide a composition of 45-60wt.% SiO2, 5-15wt.% Al2O3, 5-20wt.% CaO, 10-25wt.% BaO, 0.5-5wt.% total of MgO and SrO, 0.1-6wt.% total of TiO2 and ZrO2, 0.1-3wt.% SnO2, 0-16wt.% total of B2O3 and ZnO and 0-3wt.% total of F, SO3, As2O5, Sb2O5 and V2O5 and the resultant mixture is homogeneously melted while being stirred at 1,450-1,550 deg.C for 2-5hr. The resultant molten glass is then granulated, pulverized and powdered in a ball mill, etc.