Low melting enamel frits

摘要

A low melting enamel frit which comprises 31 to 39 wt % of SiO2, 13 to 21 wt % of B2O3, 14 to 21 wt % of Na2O, 1 to 5 wt % of K2O, 5 to 20 wt % of ZnO, 2 to 10 wt % of F2 and 2 to 9 wt % of at least one of Al2O3, ZrO2 and TiO2 provided that at least one intermediate oxide is present in an amount of 5 wt % in a maximum. The frit is capable of firing at temperatures lower than A1 transformation temperature of steel, say, 723 DEG C.