TRANSPARENT LEAD-FREE AND CADMIUM-FREE GLAZES

摘要

This invention relates to glass frit compositions free from lead and cadmium which, when combined with an organic medium and fired to a glaze, yield a glaze exhibiting a grayish discoloration caused by the presence of a carbonaceous residue therein. The grayish discoloration can be eliminated by incorporating tin oxide in the frit composition which acts to catalyze the oxidation of and/or to directly oxidize that carbonaceous residue.