PURPOSE: To provide a method for stably and successively producing highly concentrated granules of an α-sulfofatty acid alkyl ester salt with a small scale equipment and low energy by using a pressure-reducing evaporator of rotary thin film-forming type.
CONSTITUTION: An aqueous solution containing 50-80wt.% of an α-sulfofatty acid alkyl ester salt or a mixed solution obtained by adding a nonionic surfactant in an amount of ≤30wt.% based on the α-sulfofatty acid alkyl ester salt to the aqueous solution is used as a treating solution, the treating solution is successively supplied into a reducing evaporator of rotary thin film-forming type having a high-speed rotary blade, and condensation.drying of the solution is performed while forming a thin film of the treating solution on the inner wall surface by rotating the rotary blade in the heated pressure-reducing evaporator, then dried material having moisture content of ≤10wt.% is successively discharged and cooling.crushing are performed to produce the objective granules of α-sulfofatty acid alkyl ester salt.
IKEDA EISAKU
TANAKA HITOSHI
KUBO TOMOKI
OISHI TAKESHI
