Rare earth-containing alkali silicate frits and their use for the preparation of porcelain enamel coatings with improved cleanability

摘要

The present invention relates to a rare earth-containing, alkali silicate frit which may be applied to a metal substrate to provide a porcelain enamel coating which has good thermal stability, an acid resistance of A on the PEI scale and improved cleanability, wherein the frit contains, based on the total weight of the frit:PP ______________________________________ PP Oxide Wt. % PP______________________________________ PP R. sub.2 O PP 10-30 PP MgO 0-5 P P B.sub.2 O.sub.3 PP 0-5 PP SiO. sub.2 PP 45-60 PP TiO.sub.2 P P 0-10 PP F 0.5-5 PP CoO 0-3 P P NiO 0-5 PP X 12-30;PP______________________________________ P PPPwhereinPPR represents an alkali metal andPPX represents a rare earth oxide having an atomic number of 57-60, preferably cerium oxide.PPThe present invention is also directed to porcelain enamel coatings, especially for appliances, prepared from this rare earth-containing, alkali silicate frit.