GLASS FOR MAKING GRADIENT COMPONENTS BY ION EXCHANGE METHOD Russian patent published in 2000 - IPC

FIELD: glass making industry. SUBSTANCE: glass comprises no toxic components and makes it possible to decrease or increase refraction index from initial values. Refraction index increment is 19-24 x 10^-4 (mol.%)^-1. Glass comprises, mol. %: SiO₂ 45.6-52.8; TiO₂, 15.0-17.0; Li₂O, 0.1-20.0; Na₂O, 5.0-25.0; ZrO₂, 1.0-6.0; HfO₂, 1.0-6.0; Sb₂O₅, 0.2-0.3; Ta₂O₅ or Nb₂O₅ or La₂O₃ or CaO or SrO or BaO; 1.0-5.0, sum of oxides ZrO₂ and HfO₂ being 6.0-9.0 mole %. EFFECT: improved properties of glasses for optical and acoustic components. 4 tbl