Glass-ceramic article decorated with ceramic color and process for its production

US5262204A · kind A · utility

Assignee

• Schott Glaswerke · DE

Inventors

• Paul Hinz · Ingelheim am Rhein, DE
• Helmut Dislich · Budenheim, DE
• Herwig Scheidler · Mainz, DE
• Gerhard Weber · Landsberg am Lech, DE

Key dates

• Filing date: Jul 6, 1992
• Grant date: Nov 16, 1993
• Expiry date: Jul 6, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C17/3411
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention is related to a glass-ceramic article decorated with a ceramic baking finish. A SiO.sub.2 layer, about 20-200 nm thick, is placed between the decoration and the glass-ceramic material. The SiO.sub.2 layer can additionally contain, to match the refractive index to the refractive index of the glass-ceramic, up to 66.5 wt. % of oxides which change the refractive index, in particular TiO.sub.2, ZrO.sub.2, SnO.sub.2, MgO or Al.sub.2 O.sub.3. In the process to produce the decorated glass ceramic article, the SiO.sub.2 layer is preferably produced according to the known sol-gel process. Preferably, an SiO.sub.2 gel layer, optionally precondensed by a brief thermal treatment, is produced on the still-vitreous article. The decoration is applied to this gel layer and afterward the vitreous article is subjected to ceramization. The SiO.sub.2 -gel layer is converted into an SiO.sub.2 layer, and the ceramic color of the decoration is baked-in. The SiO.sub.2 layer permits, above all, the production of substantially "halo"-free decorations with sharp contours.