Method for the production of bleached, low-sultone olefin sulfonates

摘要

Aqueous solutions of alkali metal C8-22 alpha -olefin sulfonates of light color and of low sultone content are prepared rapidly and at moderate temperatures by: (a) reacting a C8-22 alpha -olefin with gaseous sulfur trioxide thereby forming a crude sulfonation product mixture containing C8-22 olefin sulfonic acids, with a content of sultones, (b) bleaching said crude sulfonation product mixture at 30 DEG C. to 80 DEG C. for 10 to 60 minutes with an aqueous alkaline bleaching solution at a pH of at least 8, (c) heating said diluted bleached sulfonation product mixture containing excess alkali to a temperature of from 140 DEG C. to 170 DEG C. until the sultone content of said sulfonation product mixture is less than 100 ppm, and (d) recovering said alkali metal C8-22 alpha -olefin sulfonates of light color and of low sultone content. A decrease in the sultone content from as much as 650,000 ppm to less than 50 ppm is possible by the method.