| 摘要 |
PROBLEM TO BE SOLVED: To provide optical glass for mold press forming, which has a refractive index of 1.65-1.75, a low softening point, low density and high weatherability. SOLUTION: The optical glass has a composition of, by weight, 35-50% SiO2, 0.1-5% Al2O3, 0-5% B2O3, 0-5% MgO, 0-5% CaO, 0-5% BaO, 0-5% SrO, 0-5% ZnO, 0.5-15% MgO+CaO+BaO+SrO+ZnO, 0-5% Li2O, 10-30% Na2O, 0-5% K2O, 25-35% TiO2, 0-15% ZrO2, 0-20% Nb2O5, 0-10% La2O3 and 0-10% Gd2O3, and the weight ratio of (Na2O+K2O)/Al2O3 is in the range of 6.5-40.
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