Glass with high proportion of zirconium-oxide and its uses

US6630420B1 · kind B1 · utility

Assignee

• Schott Glas · DE

Inventors

• Karin Naumann · Ober-Olm, DE
• Norbert Greulich-Hickmann · Mainz, DE
• Uwe Kolberg · Mainz, DE
• Werner Kiefer · Ingelheim am Rhein, DE
• Simone Monika Ritter · Mainz, DE

Key dates

• Filing date: Jan 16, 2002
• Grant date: Oct 7, 2003
• Expiry date: Jan 16, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C13/002
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The silicate glass has a composition (in % by weight, based on oxide) of SiO2, 54-72; Al2O3, 0.5-7; ZrO2, 10-20; B2O3, 0-<5; Na2O, 3-<8; K2O, 0-5; with Na2O+K2O, 2-<8; CaO, 3-11; MgO, 0-10; SrO, 0-8; BaO, 0&#8733;10; with CaO+MgO+SrO+BaO, >5-24; La2O3, 0-5; and TiO2, 0-4. The glass also contains at least 0.6 percent by weight of La2O3 or at least 0.1 percent by weight TiO2. The glass has a hydrolytic resistance in hydrolytic glass 1, an acid resistance in acid class 3 or better, preferably acid class 1, a caustic lye resistance in lye class 1, a glass transition temperature (Tg) of at least 650&deg; C., a thermal expansion coefficient (&agr;20/300) of 4.1&times;10&#8722;6 to 7.4&times;10&#8722;6/K, a refractive index (nd) of 1.53 to 1.63, an Abb&eacute; number (&ngr;d) of 48 to 58 and a negative anomalous partial dispersion in a blue spectral region (&Dgr;Pg,F) of up to &#8722;0.0130.