Production of light-colored sulfonated fatty acids and fatty acid derivatives

Claim 1

PROCES FOR LIGHTENING THE COLOR OF VISCOUS AND PASTY DARK-COLORED SULFONATION PRODUCTS OBTAINED BY THE ALPHA SULFONATION OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF SUBSTANTIALLY SATURATED FATTY ACIDS CONTAINING FROM 6 TO 28 CARBON ATOMS, THEIR ESTERS, AND MIXTURES THEREOF, WITH AN EXCESS OF GASEOUS SULFUR TRIOXIDE WHICH COMPRISES BLEACHING THE DARK-COLORED SULFONATION PRODUCT WITH WATER CONTAINING ABOUT 20-80% OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF CHLOROUS ACID, HYPOCHLOROUS ACID, CHLORIC ACID, PERCHLORIC ACID, MONPERSULFURIC ACID, CHROMIC ACID, PEROXYDISULFURIC ACID, AND PERMANGANIC ACID, THEIR SALTS AND THEIR ANHYDRIDES IN AMOUNT SUFFICIENT TO PRODUCE AN EQUIVALENT AMOUNT OF BLEACHING OXYGEN AS 0.2 TO 6% BY WEIGHT OF HYDROGEN PEROXIDE AT A TEMPERATURE BETWEEN ABOUT 20 TO 100*C. UNTIL THE COLOR OF THE PRODUCT IS SUBSTANTIALLY LIGHTENED.