OPAL GLASS

摘要

Fluorine-free opal glass has the following composition, based on the oxides of the ingredients: 55-65 % by weight of SiO2, 2-6 % by weight of Al2O3, 10-17 % by weight of Na2O, 2-10 % by weight of CaO, 0.1-6 % by weight of BaO, 0.1-6 % by weight of ZnO, 1-8 % by weight of B2O3, 4-12 % by weight of P2O5, 0.1-3 % by weight of Li2O, 0.1-3 % by weight of Sb2O3, 0-4 % by weight of MgO, the total of the weight quantities of the ingredients amounting to 100 %. In the temperature range of 20-300 DEG C, the opal glass has a thermal expansion coefficient of 8-11 x 10<-6> DEG C<-1>, enabling it to be combined with some other translucent glass, such as clear glass, and be melted in electrically-heated furnaces.