Patent ID: 7763557

Claim:
A composition for use in forming a porcelain enamel coating having a metallic appearance, said composition including a glass component comprising a glass frit, said glass frit comprising by weight: about 45% to about 55% SiO 2 , about 4 to about 20% R 2 O, about 9 to about 15% B 2 O 3 , about 4 to about 12% MnO 2 , about 1.5 to about 7% F 2 , about 0% to about 20% MO 2 , about 0% to about 10% RO, about 0.01% to about 6% NO 2 , about 0% to about 2% P 2 O 5 , about 0% to about 3% CoO, about 0% to about 3% NiO, about 0.6% to about 3% Al 2 O 3 , about 0% to about 3% Fe 2 O 3 , about 0% to about 3% CuO, about 0% to about 4% ZrO 2 , about 0% to about 2% Nb 2 O 5 , and about 0% to about 5% Sb 2 O 3 , wherein R 2 O represents at least one alkali oxide, wherein RO represents at least one alkaline earth oxide and wherein M represents at least one transition metal.