Aqueous ruthenium chloride solution for blackening ceramic surfaces

US6042884A · kind A · utility

Assignee

• BK Giulini Chemie Gmbh · DE

Inventors

• Thomas Klein · Saratoga, US
• Thomas Staffel · Grünstadt, DE
• Lysander Fischer · Wiesloch, DE

Key dates

• Filing date: Apr 30, 1998
• Grant date: Mar 28, 2000
• Expiry date: Apr 30, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B2111/82
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

An aqueous ruthenium chloride solution for blackening ceramic surfaces includes ruthenium chloride; water present in an amount effective to provide an aqueous solution of ruthenium chloride; and a buffer which is selected from the group consisting of sodium acetate, sodium propionate, potassium acetate, potassium propionate, and mixtures thereof, and which is present in an amount effective to provide the aqueous solution with a pH of at least 1.5. A method for dyeing a ceramic surface includes applying the aqueous solution of ruthenium chloride to a ceramic surface by at least one of spraying, dipping, painting and printing to provide a treated surface; drying and firing the treated surface at a temperature ranging from about 300 to about 1400.degree. C. for a period of time ranging from one half hour to five hours; and grinding and polishing the treated surface to even out the treated surface.