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

US5736476A · kind A · utility

Assignee

• Schott Rohrglas GmbH · DE

Inventors

• Eckhart Watzke · Jena, DE
• Andrea Kampfer · Jena, DE
• Peter Brix · Mainz, DE
• Franz Ott · Mitterteich, DE

Key dates

• Filing date: Sep 30, 1996
• Grant date: Apr 7, 1998
• Expiry date: Sep 30, 2016

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61J1/06
• WIPO field: Medical technology
• WIPO sector: Instruments

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.