Abstract: The invention concerns a method for preparing sulphonate salts, alkaline or alkaline-earth, corresponding to anion of general formula (I):(R—CF2—SO3−)n, through alkaline hydrolysis of sulphonyl chlorides corresponding to formula (II). The invention is characterized in that it comprises at least a step which consists in alkaline hydrolysis of sulphonyl chloride carried out in the presence of a phase-transfer agent.

Abstract: The invention relates to a process for producing an alkali metal salt of a perfluoroalkanesulfinic acid. This process includes the step of bringing a perfluoroalkanesulfonic fluoride into contact with an alkali metal salt of sulfurous acid in the presence of water. This process is useful, since this perfluoroalkanesulfonic fluoride (e.g., trifluoromethanesulfonic fluoride) is easily available.

Abstract: Process for the preparation of a fluorinated sulphonic acid compound by hydrolysis of a corresponding fluorinated sulphonyl fluoride in the presence of a tertiary amine, comprising steps of(a) recovering a mixture of a salt of the fluorinated sulphonic acid with the tertiary amine and an ammonium fluoride salt of the tertiary amine;(b) distilling off the tertiary ammonium fluoride salt and leaving a distillation remanence containing the salt of the fluorinated sulphonic acid with the tertiary amine; and(c) recovering the fluorinated sulphonic acid compound from the distillation remanence.

Abstract: A process of preparing purified alkanesulfonic acid from crude aqueous alkanesulfonic acid containing oxidizable impurities wherein the crude material is treated with a sufficient amount of chlorine to convert the oxidizable impurities to alkanesulfonyl chloride and then hydrolyzing said alkanesulfonyl chloride to alkanesulfonic acid by heating.

Abstract: A fluorocarbon carboxylic acid Rf(COOH).sub.m (Rf is C.sub.1 -C.sub.10 perfluoroalkyl group, m is 1 or 2) is prepared by the steps of hydrolyzing Rf(COF).sub.m with water to obtain an acidic solution, neutralizing the acidic solution with aqueous solution of KOH to form Rf(COOK).sub.m, precipitating and separating Rf(COOK).sub.m from the solution and converting Rf(COOK).sub.m into Rf(COOH).sub.m by acid decomposition. The content of free fluorine can extremely be reduced by treating Rf(COOK).sub.m with sulfuric acid and silica. The mother liquor is recycled after removing KF by treatment with a metal hydroxide and replenishing with KOH. In preparing a fluorocarbon sulfonic acid RfSO.sub.3 H (Rf is C.sub.1 -C.sub.3 perfluoroalkyl group) in substantially the same way, RfSO.sub.3 K is formed in aqueous solution of KOH by bringing gaseous RfSO.sub.2 F into contact with the KOH solution under normal pressure, while controlling the feed rate of RfSO.sub.

Abstract: A process for the production of an alkanesulphonic acid by hydrolyzing in the heated state an alkanesulphonyl chloride. The process is preferably continuous. The hydrolysis reaction is initiated by the instantaneous use of energy released by the state change of one of the reagents internal to the system.