Procedure for the production of Ethercarbonsäuresalzen

The present invention provides a production process for an ether carboxylate salt in which process the ether carboxylate salt is obtainable with a good yield, and the amount of expensive catalyst, as used, can be saved, and the recovery of the catalyst is easy. The production process for an ether carboxylate salt comprises the etherification step of reacting a hydroxyl-group-containing organic compound and a carboxyl-group-containing organic compound in an aqueous medium in the presence of a catalyst containing a rare earth element, wherein the carboxyl-group-containing organic compound is at least one compound selected from the group consisting of carboxyl-group-containing unsaturated organic compounds and carboxyl-group-containing epoxy compounds. This process is characterized in that the pH of the aqueous medium is in the range of 9 SIMILAR 13, but not including 9, and in that the amount of the catalyst, as used, is in the range of 0.0001 SIMILAR 0.4 mol per 1 mol of the carboxyl-group-containing organic compound. After the etherification step, the rare earth element is separated and recovered in the form of a water-insoluble salt. In the etherification step, the resultant ether compound is deposited in the course of the reaction.