Abstract: The invention provides a fatty acid alkyl ester sulfonate metal salt mixture of (a) a fatty acid alkyl ester sulfonate metal salt having an endothermic peak area at 50 to 130° C. of less than 50% relative to the whole endothermic peak area at 0 to 130° C. as measured on a differential scanning calorimeter, and (b) a fatty acid alkyl ester sulfonate metal salt having an endothermic peak area at 50 to 130° C. of 50% or more relative to the whole endothermic peak area at 0 to 130° C. as measured on a differential scanning calorimeter, with a ratio of (a) to (b) by mass of 95/5 or less. The mixture of the invention is excellent in anti-caking properties.

Abstract: A solid fatty acid alkyl ester sulfonate metal salt is disclosed having an endothermic peak area between 50° C. and 130° C. of 50% or more relative to the whole endothermic peak area between 0° C. and 130° C. when determined using a differential scanning calorimter. A method for producing a fatty acid alkyl ester sulfonate metal salt powder is also disclosed, including a step of pulverizing the solid fatty acid alkyl ester sulfonate metal salt in a pulverizer, with the internal temperature of the pulverizer being adjusted to 30° C. to 50° C.

Abstract: The invention provides a fatty acid alkyl ester sulfonate metal salt mixture of (a) a fatty acid alkyl ester sulfonate metal salt having an endothermic peak area at 50 to 130° C. of less than 50% relative to the whole endothermic peak area at 0 to 130° C. as measured on a differential scanning calorimeter, and (b) a fatty acid alkyl ester sulfonate metal salt having an endothermic peak area at 50 to 130° C. of 50% or more relative to the whole endothermic peak area at 0 to 130° C. as measured on a differential scanning calorimeter, with a ratio of (a) to (b) by mass of 95/5 or less. The mixture of the invention is excellent in anti-caking properties.

Abstract: A solid fatty acid alkyl ester sulfonate metal salt is disclosed having an endothermic peak area between 50° C. and 130° C. of 50% or more relative to the whole endothermic peak area between 0° C. and 130° C. when determined using a differential scanning calorimeter, A method for producing a fatty acid alkyl ester sulfonate metal salt powder is also disclosed, including a step of pulverizing the solid fatty acid alkyl ester sulfonate metal salt in a pulverizer, with the internal temperature of the pulverizer being adjusted to 30° C. to 50° C.

Abstract: A process for producing powder, flakes, or pellets containing ?-sulfo fatty acid alkylester salt in high concentrations, the process including: (1) a step of preparing a paste containing ?-sulfo fatty acid alkylester salt; (2) a step of aging the thus obtained paste; (3) a step of making the aged paste into flakes or pellets containing equal to or less than 10 wt % of water and then optionally crushing the resulting flakes or pellets into a powder having an average particle diameter of 100-1500 ?m; and (4) a step of aging The powder, flakes, or pellets.

Abstract: A process for producing powder, flakes, or pellets containing ?-sulfo fatty acid alkylester salt in high concentrations, the process including: (1) a step of preparing a paste containing ?-sulfo fatty acid alkylester salt by a series of reactions of sulfonating a fatty acid alkylester with a sulfonating gas by contact with each other, esterifying the sulfonated product with a lower alcohol, neutralizing the esterified product, and bleaching the neutralized product, to give a paste containing ?-sulfo fatty acid alkylester salt; (2) a step of aging the thus obtained paste; (3) a step of making the aged paste into flakes or pellets containing equal to or less than 10 wt % of water, or a step of making the aged paste into flakes or pellets containing equal to or less than 10 wt % of water and then crushing the resulting flakes or pellets into a powder having an average particle diameter of 100-1500 ?m; and (4) a step of aging the powder, flakes, or pellets.