GLASS HAVING STABILITY NOTABLY IMPROVED IN TERMS OF DAMAGE TO RADIATION, AND PROCESS FOR PRODUCTION THEREOF AND USE THEREOF

摘要

A glass having a high internal transmission as well as a low tendency to physical compaction caused by radiation and a low solarization tendency, comprising: 18 to 31% by weight SiO2.0 to 7% by weight Na2O3.0 7% by weight of K 2 O, 65 to 84% by weight of PbO, 0.001 to 1% by weight of As 2 O 3 + As 2 O 5, which is characterized by a content of from 0 to 5000 ppm of Sb 2 O 3 O at 500 ppm of TiO 2 O at 100 ppm of CuO0 at 1000 ppm F.La Σ (As2O3, As2O5, Sb2O3, F) ≥ 20 ppm and the ratio As (III) / As (V) is at least 0.5. This glass is suitable for use as an optical element.