Ion retardation resins particularly useful for desalting caustic solutions are prepared by employing ion exchange resins consisting essentially of a mixture of a reticular, insoluble, cross-linked styrene/divinylbenzene copolymer with an entrapped non-leachable polymer of acrylic acid contained therein and where the amount of carboxylic acid groups on the polyacrylic acid are in substantial excess over the amount needed to react with all the quaternary ammonium groups which are nuclear substituted on the styrene copolymer chains.