Process for refining crude fluoroalkylsulfonic acid with the use of water

摘要

A process for refining a crude fluoroalkylsulfonic acid represented by the general formula RfSO3H wherein Rf is a fluoroalkyl group having 1 to 4 carbon atoms into a highly refined one substantially free of impurities, said process comprising the steps of: (a) providing said crude fluoroalkylsulfonic acid, (b) mixing said crude fluoroalkylsulfonic acid with water or said water and an active silica to obtain a mixture, (c) stirring said mixture while maintaining said mixture at a higher temperature than room temperature, and (d) subjecting the mixture treated in said step (c) to distillation.