ADDITIVES FOR LEAD- AND CADMIUM-FREE GLAZES

摘要

This invention relates to a method for eliminating the grayish discoloration which commonly develops when leadfree and cadmium-free glass frits are applied to substrates utilizing an organic medium and thereafter fired to fuse the frit particles into a glaze. The grayish discoloration contains a carbonaceous residue from the organic medium. The method comprises the four general steps: (1) adsorbing a coating of a strongly oxidizing metal ion species onto the surface of the frit particles; (2) mixing the coated frit particles with an organic medium; (3) applying that mixture to a substrate; and (4) firing the mixture to eliminate the organic medium and to oxidize the carbonaceous residue while fusing the frit particles into a glaze.