HIGH CHEMICALLY RESISTANT AND LOW VISCOUS BOROSILICATE GLASS WHICH COMPRISES ZIRCONIUM OXIDE AND LITHIUM OXIDE Russian patent published in 1999 - IPC

FIELD: multipurpose packing material for pharmaceuticals. SUBSTANCE: high chemically resistant and low viscous borosilicate glass which comprises zirconium oxide and lithium oxide and is hydrolysis resistant according to class I, DJN ISO 719, acid resistant according to class I, DJN 12116 and caustic alkali resistant according to class I, DIN ISO 659 with low working point V_A between 1180 C and 1230 C and thermal expansion factor α_20/3004.9×10^-6k^-1. Borosilicate glass comprises, wt.%: SiO₂, 73-75; B₂O₃, 7-10; 5-7 Al₂O₃; ZrO₂, 1-3; Li₂O, 0.5-1.5; Na₂O, up to 10; K₂O, up to 10; equal to or greater than 7.5 SiO₂/B₂O₃ ratio; Σ SiO₂+Al₂O₃+ZrO₂, 80-83. Glass comprises 3.0 wt % at least one component from MgO, CaO, BaO, SrO, ZnO, fluorides, Σ MgO+CaO+BaO+SrO+ZnO is equal to or greater than 3.0. EFFECT: improved properties of borosilicate glass. 8 cl, 2 tbl