Borosilicate glass of high chemical resistance and low viscosity which contains zirconium oxide and lithium oxide

Abstract

The invention relates to a borosilicate glass of high chemical resistance and low viscosity which contains zirconium oxide and lithium oxide. The borosilicate glass has hydrolytic resistance (in accordance with DIN ISO 719), class 1 acid resistance (in accordance with DIN 12116), and class 1 alkali resistance (in accordance with DIN ISO 659), and with a low operating temperature V.sub.A of between 1180.degree. C. to 1230.degree. C. and a coefficient of thermal expansion .alpha..sub.20/300 of 4.9.times.10.sup.-6 K.sup.-1. The borosilicate glass has the composition (in % by weight, based on oxide): SiO.sub.2 73-75; B.sub.2 0.sub.3 7-10; Al.sub.2 0.sub.3 5-7; ZrO.sub.2 1-3; Li.sub.2 0 0.5-1.5; Na.sub.2 0 0-10; K.sub.2 0 0-10; MgO 0-3; CaO 0-3; BaO 0-3; SrO 0-3; ZnO 0-3; ratio of SiO.sub.2 /B.sub.2 0.sub.3 .gtoreq.7.5; .SIGMA. SiO.sub.2 +Al.sub.2 0.sub.3 +ZrO.sub.2 80-83 and .SIGMA. MgO+CaO+BaO+SrO+ZnO.ltoreq.3, and fluorides 0-3. The glass is particularly suitable for use as a versatile primary packaging material for pharmaceuticals, for example as ampule glass.

Dependencies are inferred from the claim text.