| 摘要 |
<p>PCT No. PCT/US96/16192 Sec. 371 Date Feb. 2, 1998 Sec. 102(e) Date Feb. 2, 1998 PCT Filed Oct. 9, 1996 PCT Pub. No. WO97/14661 PCT Pub. Date Apr. 24, 1997The invention relates to glasses which absorb UV radiation and which have the following composition, in wt. %: SiO2 30-52; ZnO 0-8; B2O3 12-22; PbO 0-2; ZrO2 5-14; Y2O3 0-15; Al2O3 0-12; La2O3 5-25; Li2O 1.5-3.5; TiO2 0-2; Na2O 0-6; HfO2 0-2; K2O 2-9; Nb2O5 0-2; MgO 0-5; Ta2O5 0-2; CaO 0-5; MoO3 0-2; SrO 0-9; WO3 0-2; BaO 0-14; SnO 0-4; Sb2O3 0-4; SnO2 0-4; AS2O3 0-4; CdO 0-1; CuO 0.15-1; F 0-2; Cl 0-3; Br 0-3; I 0-2 with the following conditions: Li2O+Na2O+K2O (X2O) 7-14; MgO+CaO+SrO+BaO (XO) 12-20; ZrO2+Al2O3<15; F+Cl+Br+I 0.2-4.0; TiO2+PbO+Nb2O5</=2; AS2O3+Sb2O3+SnO2+SnO 0.05-4.0 and a ratio R=(M2O+2MO-Al2O3-ZrO2)/B2O3 where M2O and MO represent the total content of alkali metal oxide and the total content of alkaline-earth metal oxides, respectively, expressed in mol. %, between 0.50 and 1.00. Application to the manufacture of ophthalmic lenses, notably.</p> |
