GLAZED ROOFING TILE HAVING SOMBER SILVER COLOR AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain a glazed roofing tile having somber silver color, by using a glazing composed of specific amounts of MnO and oxides of Zr, Ti, V and Sn and optionally an oxide of Sb, applying the glazing to unglazed tile and baking the tile under oxidizing condition. CONSTITUTION:The glazing used in the present roofing tile contains 0.9-1mol of MnO as an alkaline component and 0.2-1.5mol of oxides of Zr, V and Sn and optionally an oxide of Sb in total represented by Segel designation. MnO may be substituted with =0.3mol of PbO. The glazing is applied to unglazed roofing tile and baked at 980-1,200 deg.C under oxidizing condition.