Patent ID: 8778455

Claim:
A method of forming an enamel coating on a substrate, the method comprising: providing a substrate; providing a composition comprising (i) a glass component and (ii) at least one additive selected from the group consisting of fluorine and NO 2 , wherein the glass component includes by weight from about 7.1% to about 7.9% Na 2 O, from about 7.0% to about 7.7% K 2 O, from about 0.6% to about 1.0% ZnO, from about 2.7% to about 3.3% BaO, from about 19.3% to about 20.7% Al 2 O 3 , from about 10.8% to about 11.8% SiO 2 , from about 0.7% to about 1.2% TiO 2 , from about 14.4% to about 15.6% ZrO 2 , from about 29.20% to about 31.3% P 2 O 5 , and from about 0.1% to about 5.2% Co 2 O 3 ; depositing a layer of the composition on the substrate; and firing the layer to thereby form an enamel coating on the substrate.