Self-opacifying enamel frits for enameling aluminium or aluminium alloys

摘要

Self-clouding, chemical resistant enamel frit compsn. has a heat expansion coefficient of 460-475x10<-7>k<-1> and glass transition temp. of 410-440 degrees C, and contains (in wt.%): 32-37 SiO2, 0-4 B2O3, 0-3 Al2O3, 4-9 Li2O, 10-18.5 Na2O, 9-14 K2O, 0-2 MgO, 0-2 SrO, 0-4 BaO, 6-11 V2O5, 0-3 P2O5, 0-5 Sb2O3, 14-21 TiO2, 0-2 ZnO, 0-2 SnO2; 0-1 MoO3, and ratio of (TiO2+Sb2O3+SnO2+ZnO+Al2O3) to (Li2O+Na2O+K2O) is 0.52:0.82. A dross for enamelling Al (alloys) is also claimed consisting of 100 (wt. pts.) of the above enamel, 0-15 clouding agent, 2-10 auxiliary agent, 0-5 pigment, and 50-65 water.