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US 5,670,470 AGranted
Percarbonate stabilised by coating with an aqueous solution of phosphate and boron compounds
AssigneeSolvay Interox Limited
InventorsGraham Robert Horne, Alun Pryce James
Life of this patent
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Abstract
A process for stabilising percarbonate by coating with a coating agent. The percarbonate particles are treated with a concentrated aqueous solution containing at least one boron compound selected from the metal and ortho boric acids and at least one phosphate. Water is removed to provide the coated percarbonate particles which are useful in bleaching and washing compositions.
Claims16
A process for stabilising alkali metal percarbonate particles by coating by means of a coating agent which comprises:
- contacting the percarbonate particles with an aqueous solution containing at least 15% by weight of a coating agent, said coating agent solution being prepared by dissolving at least one boric acid selected from the group consisting of metal and ortho boric acids and at least one phosphate selected from the group consisting of alkali metal, alkaline earth metal, and ammonium phosphates, the boric acid calculated as H.sub.3 BO.sub.3 constituting from 5-85% by weight of the boric acid and phosphate, and the phosphate constituting from 15-95% by weight of the boric acid and phosphate;
- and
- removing water to provide a coating of the coating agent on the percarbonate particles, the amount of the coating agent being from 0.5 to 20% by weight based on the weight of the coated alkali metal percarbonate particles.
Dependencies are inferred from the claim text.