COMPOSITIONS OF SILICON-SODIUM-CALCIUM GLASSES, AND USE THEREOF Russian patent published in 2002 - IPC

FIELD: manufacture of glasses. SUBSTANCE: composition comprise, wt %: SiO₂, 45-68; Al₂O₃, 0-20; ZrO₂, 0-20; B₂O₃, 0.5-4; Na₂O, 2-12; K₂O, 3.5-9; CaO, 1-13, MgO, 0-8. Total content of SiO₂, Al₂O₃ and ZrO₂ is equal or less than 70%, total content of Al₂O₃ and ZrO₂ is equal or higher than 2%, total content of Na₂O and K₂O is equal or higher than 8%. Substrate for emission screens and antiproof glazing are manufactured from glasses of said compositions. EFFECT: greater mechanical strength of glass. 12 cl, 1 tbl