Coated sodium percarbonate particles, method of producing them and their use

摘要

In the prior art, sodium percarbonate is coated with compounds which produce a stabilizing action in order to increase the shelf life. There is a need for an improved, boron-free, coating for sodium percarbonate. Proposed by the invention is a particle coating containing sodium carbonate plus one or more optionally partly hydrated magnesium compounds, preferably magnesium sulphate, in a single coat or in separate coats. The coating preferably contains two coats. The particles are produced by spraying aqueous solutions containing the coating compounds on to sodium percarbonate in a fluidized bed and at the same time evaporating off the water. Their long shelf life makes particles coated in this way suitable for use in washing, bleaching and cleaning agents.