Lead-free and cadmium-free glass compositions for glazing, enameling and decorating glass of glass-ceramics

US6043171A · kind A · utility

Assignee

• Schott Glas · DE

Inventors

• Friedrich Siebers · Nierstein, DE
• Ottmar Becker · Langen, DE
• Waldemar Weinberg · Kiebitzreihe, DE
• Petra Auchter-Krummel · Wörrstadt, DE

Key dates

• Filing date: May 19, 1998
• Grant date: Mar 28, 2000
• Expiry date: May 19, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C2217/72
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The lead- and cadmium-free glass composition for glazing, enameling and decorating glass or glass-ceramic articles contains high quartz and/or keatite solid solution crystals as principal crystalline phases after crystallization and a low thermal expansion coefficient of less than 2.times.10.sup.-6 /K at temperatures between 20 and 700.degree. C. This glass composition contains Li.sub.2 O, 0 to 5% by weight; Na.sub.2 O, 0 to 5% by weight; K.sub.2 O, less than 2% by weight; MgO, 0 to 3% by weight; CaO, 0 to 4% by weight; SrO, 0 to 4% by weight; BaO, 0 to 4% by weight; ZnO, 0 to 4% by weight; B.sub.2 O.sub.3, 15 to 27% by weight; Al.sub.2 O.sub.3, 10 to 20% by weight; SiO.sub.2, 43 to 58% by weight; TiO.sub.2, 0 to 3% by weight and ZrO.sub.2, 0 to 4% by weight, Sb.sub.2 O.sub.3, 0 to 2% by weight; F, 0 to 3% by weight in exchange for oxygen and up to 30% by weight of at least one inorganic pigment resistant to a burning-in temperature on the glass or the glass-ceramics. The sum total amount of Li.sub.2 O, Na.sub.2 O and K.sub.2 O must be from 1 to 10% by weight. An average bending tensile strength of a glass-ceramic or glass article completely coated with the glass composition after …