Degussa Aktiengesellschaft

Claas-Juergen Klasen

Birgit Bertsch-Frank

Martin Bewersdorf

Thomas Lieser

Klaus Mueller

Ruediger Schuette

Peter Schubert

Ivan Pelgrims

Juergen Rollmann

In order to increase active oxygen stability, sodium percarbonate is coated with single or multiple layers of various substances. Sodium percarbonate particles consist of a core of sodium percarbonate fluidized bed spray granulate and sodium sulphate, which may be partially hydrated, as the sole constituent of a single coating layer. The particles exhibit both elevated active oxygen stability and very good ensilability. The coating layer is applied by spraying an aqueous Na.sub.2 SO.sub.4 solution onto the particles to be coated, which were themselves produced by fluidized bed spray granulation, in a fluidized bed and vaporizing water at a fluidized bed temperature of 35 to 100.degree. C.

Coated sodium percarbonate particles, process for the production thereof

Coated sodium percarbonate particles contain, in the coating, sodium carbonate and also one or more magnesium compounds, preferably magnesium sulfate, optionally in a partially hydrated form, in a single layer or in separate layers in the coating. Preferred coated sodium percarbonate particles contain two layers. Particles are prepared by spraying aqueous solutions containing the coating components onto sodium percarbonate in a fluidized bed with simultaneous evaporation of the water. The particles are suitable for use in detergents, bleaches and cleansing agents.

Coated sodium percarbonate particles, a process for their preparation

Coated sodium percarbonate particles, a process for their production and

Sodium perborate monohydrate having an O.sub.a content of 14 to 16%, a bulk density of at least 600 g/l, an abrasion index (ISO 5937) of less than 8%, and a specific surface of less than 5 m.sup.2 /g can be produced by a fluidized bed--spraying process by spraying a sodium perborate solution produced by combining and mixing an aqueous hydrogen peroxide solution with an aqueous sodium metaborate solution, whereby the contact time between the combination of the solutions and the spraying is at least 2 seconds and preferably at least 5 seconds.

Process for producing abrasion-resistant sodium perborate monohydrate

Method for the preparation of stabilized sodium percarbonate

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Freigericht, Germany

Claas-Juergen Klasen