Alkali-free aluminoborosilicate glass and its use

US5770535A · kind A · utility

Assignee

• Schott Glaswerke · DE

Inventors

• Peter Brix · Mainz, DE
• Gerhard Lautenschlager · Reinheim, DE
• Klaus Schneider · Zell am Harmersbach, DE
• Thomas Kloss · Jena, DE

Key dates

• Filing date: Jan 31, 1997
• Grant date: Jun 23, 1998
• Expiry date: Jan 31, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C3/093
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

An alkali-free aluminoborosilicate glass preferably with a thermal expansion .alpha..sub.20/300 of about 3.7 .times.10.sup.-6 /K, an annealing temperature OKP of above 700.degree. C., a treatment temperature V.sub.A of less than 1220.degree. C., and very good chemical stability, which can be produced in a float unit and has the following composition (in % by weight based on oxide): SiO.sub.2 52-62; B.sub.2 O.sub.3 4-14; Al.sub.2 O.sub.3 12-20; MgO 0-8; CaO 4-11; BaO 0-2; ZnO 2-8; ZrO.sub.2 0-2; SnO.sub.2 0-2. The ratio of Al.sub.2 O.sub.3 /B.sub.2 O.sub.3 is preferably equal to or greater than 3. The glass is especially suitable for use in display technology.