US Patent 7951312 Borosilicate glass with UV-blocking properties for pharmaceutical packaging

The borosilicate glass for pharmaceutical packaging has a transmission τ in the visible range of more than 80% at a wavelength of 400 nm, a transmission τ in the UV range of at most 0.1% at wavelengths under 260 nm (each at a sample thickness of 1 mm), a transformation temperature Tg of 550° C. to 590° C. and a processing temperature VA of 1100° C. to 1200° C. The glass has a composition, in wt. % on an oxide basis, of SiO2, 60-80; B2O3, 5-15; Al2O3, 2-10; TiO2, 0.5-7; Σ Li2O+K2O+Na2O, 3-10; Σ alkaline earth oxides, 0.5-10; ZrO2, 0-3; and Fe2O3, 0-0.2. The glass is suitable for packaging UV-sensitive substances but nevertheless permits optical quality control.