Lead- and cadmium-free glass compsn.

摘要

A Pb-free and Cd-free glass compsn., for glazing, enamelling and decorating glass has the compsn. (by wt., on oxide basis) 2.6-6 (pref. 2.8-5)% Li2O, 4-10 (pref. 5-9.5)% Na2O, 0-2% K2O, less than 13% Li2O + Na2O + K2O, 0-4 (pref. 0-2.5)% MgO, 0-7 (pref. 0-4)% CaO, 0-4 (pref. 0-3)% SrO, 3-13 (pref. 4-11)% ZnO, 13-28 (pref. 16-27)% B2O3, 0-17.5 (pref. 0-10)% Al2O3, 30-54 (pref. 40-52)% SiO2, 0-5 (pref. 0-3.5)% TiO2, 0-2 (pref. 0-1.5)% ZrO2 and 0-3.4 (pref. 0-2.8)% F substituting for O. The glass compsn. may contain up to 2 wt.% total BaO, SnO2, P2O5 and/or La2O3, and pref. contains 11 to less than 15.8 wt.% Li2O + Na2O + K2O + F, 1.5-7.5 wt.% CaO + SrO + MgO and 44-58 wt.% Al2O3 + SiO2 + SnO2 + TiO2 + ZrO2. The glass compsn. has a transition temp. of 430-500 (pref. 440-490) deg C, a softening temp. of 540-600 (pref. 550-595) deg C and a working temp. of 700-800 (pref. 720-780) deg C.