Coated alkali metal peroxy salts and process for their preparation

US5681807A · kind A · utility

Assignee

• Solvay Interox GmbH · GB

Inventors

• Helmut Honig · Geretsried, DE
• Werner Doetsch · Homborn, DE
• Manfred Mathes · Homborn, DE
• Klaus-Guenter Gerling · Laatzen, DE
• Gerd Hecken · Vettelschoß, DE

Key dates

• Filing date: Oct 1, 1996
• Grant date: Oct 28, 1997
• Expiry date: Oct 1, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C11D17/0039
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The use of lactobionic acid, lactobionic acid salts and/or lactobionic acid derivatives as covering material is disclosed for coating alkali metal peroxy salts, in particular for coating sodium percarbonate. In an advantageous alternative of the invention, alkali metal peroxy salts are provided with a covering layer that contains as covering materials lactobionic acid and/or lactobionic acid salt mixed with boric acid and/or a boric acid salt as additional covering material. This coating stabilizes the alkali metal peroxy salts and protects them against humidity and decomposition. In another advantageous alternative, lactobionic acid, lactobionic acid salts and/or lactobionic acid derivatives are used in combination with or in particular mixed with an inorganic mineral salt mixture of alkali metal sulphate and alkali metal chloride as additional covering material for coating alkali metal peroxy salts, in particular for coating sodium percarbonate. The invention is preferably used for coating and stabilizing sodium percarbonate.