METHOD FOR THE PREPARATION OF POLYDICARBOXYSACCHARIDES, AND SUBSTITUTES FOR PHOSPHATES IN DETERGENTS, BASED ON THE POLYDICARBOXYSACCHARIDES

摘要

A method for the preparation of polydicarboxysaccharides is provided wherein polysaccharides, such as starch and starch derivatives, are oxidised in the presence of hypobromite and/or hypoiodite and a low oxidising agent concentration is maintained during the oxidation reaction. The low concentration of oxidising agent can be maintained by adding the oxidising agent during the oxidation reaction. The hypobromite or hypoiodite is preferably formed in the reaction medium by oxidation of a catalytic amount of bromide or iodide, either by addition of hypochlorite or by passing an electric current. The product obtained by the method has good calcium and magnesium binding properties and is biodegradable, and thus it is very suitable for use as a builder in detergent compositions.