GLASS ENAMEL FOR AUTOMOTIVE APPLICATIONS

摘要

The present invention provides lead and cadmium free glass enamel compositions. In one embodiment of the invention, glass frits includes from about 0.1 percent by weight to about 15 percent by weight Nb2O5, less than about 3 percent by weight alkali metal oxides, less than about 3 percent by weight ZnO, less than about 1 percent by weight B2O3, and precursors from which Bi2SiO5 can be crystallized upon firing, said precursors including Bi2O3, and SiO2. Glass frits according to the present invention preferably further include up to about 25 percent by weight of coloring oxides, such as CeO2, Co3O4, In2O3, SnO, Cr2O3, CuO, Fe2O3, MnO2, MoO3, NiO, and V2O5. By incorporating various amount of coloring oxides into the compositions, the degree of crystallization and the rate at which crystallization occurs upon firing of the compositions can be controlled. Compositions according to the present invention form enamels upon firing which exhibit excellent resistance to acids, water, and alkalis as compared to enamels formed from prior art lead and cadium free glass enamel compositions.