| abstract |
In a process for producing polycarboxylic acids or their salts from polysaccharides by oxidation with nitrogen dioxide/dinitrogen tetroxide with the conversion of at least a part of the primary alcohol groups of the polysaccharides into carboxyl groups and where appropriate the at least partial neutralisation of the carboxylic acid groups produced, the reaction time required is to be shortened and the necessary quantity of nitrogen dioxide reduced. This is essentially attained in that the oxidation reaction is accomplished at above room temperature in the presence of oxygen. The resultant polycarboxylates are, for instance, used as builders or co-builders in washing or cleaning agents. |