OPTICAL GLASS Russian patent published in 1995 - IPC

FIELD: glass industry. SUBSTANCE: optical glass has the following composition, wt. -% barium phosphate Ba(PO₃)₂ 23-40; aluminium phosphate Al(PO₃)₃ 10-22.5; magnesium oxide MgO 1.4-5.7; zinc oxide ZnO 0.8-5; cadmium oxide CdO 1-17; barium oxide BaO 5-22; barium fluoride BaF₂ 1-20; aluminium fluoride AlF₃ 3-7.5; strontium oxide and/or strontium fluoride SrO, SrF₂ 3-9.2. Glass can contain at least two oxides from the group, wt.-% potassium oxide K₂O 0.5-1.5; cesium oxide Cs₂O 0.5-1.5; yttrium oxide Y₂O₃ 1-5; tantalum oxide Ta₂O₅ 2-10; silicon oxide SiO₂ 0.5-1.5. Transparency of glass at wavelength 400 nm is 98-99.2% Glass is used for lens making. EFFECT: enhanced quality of glass. 2 cl, 1 tbl