| 摘要 |
New photochromic alumino-phosphate glass contg. dispersed crystals of silver halide, has compsn. by wt. 8.5-25% SiO2, 13-36.5% Al2O3, 7.5-33.5% P2O5, 7-28% B2O3, and 7-20.5 R2O where R is Na, K and/or Li, with max. 5% Li2O; and the SiO2 is min. 16% when the B2O3 is 8%; and the glass contains 0.05% min. Ag2O. Pref. compsns. are (a) min. Al2O3 with 25.5% max. P2O5 and 24.5% max. B2O3; or (b) 25%min. B2O3 with max. 20% Al2O3 and 20% max. P2O5; or (c) 21.5% min. P2O5 with 26% max. Al2O3 and 17.5% max. B2O3; (d) 0.06% min. Ag2O. The glass may also contain 1-21% of the following: 0-4% MgO, 0-6.5% CaO, 0-10% SrO and/or 0-21% BaO. The T2O may be a mixt. of K2O with 5% max. each Na2O and Li2O; or K2O used alone; or max. 14% Na2O used alone. The glass may also contain 6% max., esp. 3% max. TiO2; and/or 10% max., esp. 7% max. ZrO2; and/or 8% max. PbO. Finally, 100% of the glass may be provided with 0.06-0.6% Ag2O, 0.005-1% CuO, 0.2-2%Cl+Br, 0-1% Cl, and/or 0.08-1% Br.: Spectacle lenses can be made with a high speed of response to increase or decrease of light. |
