Patent attributes
A porcelain enamel composition having a metallic appearance is disclosed. The composition comprises about 45% to about 55% SiO2, about 4 to about 20% R2O, about 9 to about 15% B2O3, about 4 to about 12% MnO2, about 1.5 to about 7% F2, about 0% to about 20% MO2, about 0% to about 10% RO, about 0% to about 6% NO2, about 0% to about 2% P2O5, about 0% to about 3% CoO, about 0% to about 3% NiO, about 0% to about 3% Al2O3, about 0% to about 3% Fe2O3, about 0% to about 3% CuO, about 0% to about 4% ZrO2, about 0% to about 2% Nb2O5, and about 0% to about 5% Sb2O3, wherein R2O represents at least one alkali oxide, wherein RO represents at least one alkaline earth oxide and wherein MO2 represents at least one opacifying pigment selected from the group consisting of ZrO2, TiO2, CeO2, SnO2 and La2O3.
