Abstract: The present invention provides an article of cookware bearing a thermally cured sol-gel coating that is transparent, adherent, and exhibits excellent durability and chemical resistance. Preferably, the sol-gel coating composition, which includes a colloidal suspension of hydrolyzed metal alkoxide particles in an organic solvent, is applied to bare metal such as aluminum and its alloys or to porcelain enameled metals or other substrates using a conventional wet application technique such as spraying. The sol-gel coating composition is then thermally cured at a temperature below about 500° C. to provide a durable transparent inorganic polymer coating that exhibits excellent physical and chemical resistance. The present invention also provides a method of making such an article of cookware.

Abstract: The present invention provides a composition for use in forming an opaque porcelain enamel coating on a metal substrate. A porcelain enamel coating formed using a composition according to the invention readily adheres to metal substrates such as, for example, steel, that are degreased-only. Furthermore, such a porcelain enamel coating displays an acid resistance of A according to ISO 2722 and good easy-to-clean properties. The composition according to the invention includes a glass component including by weight from about 45% to about 55% SiO2, from about 8% to about 17% B2O3, from about 1.8% to about 17.7% SrO+BaO, from about 1.9% to about 10% Li2O, up to about 6% ZrO2, from about 2% to about 11% TiO2, from about 1.5% to about 6% K2O, from about 1% to about 4% MoO3, from about 0.3% to about 13% Na2O, up to about 2% NiO, up to about 3% Al2O3, up to about 2.9% MnO, up to about 0.8% CoO, up to about 3% MgO, up to about 5% CaO, and up to about 2% Sb2O3.