Coated stabilized cadmium chalcogenide pigments

US4093777A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Heinrich Heine · Krefeld, DE
• Peter Woditsch · Krefeld, DE
• Theodor Bohmann · Leverkusen, DE
• Dieter Rade · Krefeld, DE

Key dates

• Filing date: Oct 6, 1975
• Grant date: Jun 6, 1978
• Expiry date: Oct 6, 1995

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31667
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A stabilized cadmium chalcogenide, in which optionally zinc and/or mercury is present in the lattice, carrying at least one coating of a sparingly-soluble sulfide is produced by adding at least one water-soluble salt of an element forming a sparingly-soluble sulfide to an aqueous chalcogenide suspension, mixing with a compound releasing sulfide ions and/or mixing the cadmium chalcogenide suspension with a soluble thio-compound of an element forming a sparingly-soluble sulfide thereby to precipitate a sparingly-soluble sulfide onto the chalcogenide, subsequently filtering, optionally washing, drying and annealing the aftertreated chalcogenide. Suitable sparingly-soluble sulfides are, for example, the sulfides of the elements Zn, Hg, In, Sn, Pb, As, Sb, Bi, V, Mo, W, Cu and Ag.