Coated Sodium percarbonate

Coated Sodium percarbonate is the more commonly commercialized peroxide compared with the uncoated type. But the uncoated product is still the preferred ingredient for simply mixing with enough quantity of soda ash and some surfactants to form the popular oxygen bleaches.
The name "Sodium percarbonate " (SPC) does not reflect the structure of this oxidizing agent, which is in fact a carbonate perhydrate: 2 Na2CO3• 3 H2O2. Although SPC is very storage-stable if dry, the solid material has a slight vapour pressure of hydrogen peroxide leading to exchange with water or to violent reactions with oxidizable substrates, even in the solid state.

The present invention relates to coated Sodium percarbonate particles consisting of a core of sodium percarbonate produced in the aqueous phase by crystallization and a firmly adhering, two-layer coating surrounding the core. The Sodium percarbonate particles coated according to the invention by means of a fluidized bed spray process are distinguished by high active oxygen stability in detergents and also by high abrasion resistance and good silo storage properties. The invention further relates to the use of the coated Sodium percarbonate particles in detergents, cleaning agents and bleaches.