Process for producing alkali salts of alkylsulphonic acids

摘要

A process for producing alkali salts of alkylsulphonic acids, wherein the alkyl contains 11 to 18 carbon atoms which comprises outgassing the reaction mixture resulting from sulphoxidation of n-paraffins, having from 11 to 18 carbon atoms, taken either separately or in various combinations and consisting of corresponding alkylsulphonic acids, sulphuric acid, unreacted n-paraffins, sulphurous anhydride and water; the outgassed reaction mixture is neutralized with an aqueous solution of an alkali; the neutralizate is maintained at a temperature of from 100 to 160 DEG C under a gauge pressure of from 1 to 6 atmospheres to allow stratification into two layers: the upper layer comprising the unreacted n-paraffins, the lower layer comprising an aqueous solution of a mixture of alkali salts of corresponding alkylsulphonic acids and alkali salts of sulphuric acid; the upper layer is separated and the lower layer is added with aliphatic saturated monohydric C1-C4 alcohols (weight ratio between the lower layer and the alcohol is 1:1-2); the resulting aqueous alcoholic solution of the alkali salts is maintained at a temperature of from 2 to 20 DEG C to precipiate the alkali salts of sulphuric acid; the precipitate is separated from the aqueous alcoholic solution of alkali salts of corresponding alkylsulphonic acids; the solution is evaporated. The resulting desired products contain a minor amount of mineral impurities (below 1 wt.% of solids) and are efficient emulsifiers adapted for use in polymerization processes.