Method for producing sulfonate composition

A method for producing a sulfonate composition comprising, reacting (A) a compound represented by the following general formula (1) [hereinafter referred to as component (A)] in the presence of one or more solvents selected from (B) (B1) an organic solvent [hereinafter referred to as component (B1)] and (B2) water [hereinafter referred to as component (B2)] with (C) a sulfonating agent [hereinafter referred to as component (C)] to obtain a mixture containing (S) a sulfonate represented by the following general formula (2) [hereinafter referred to as component (S)], and removing an insoluble component from the mixture,

• ROOC—(CH2)n—CH═CH—(CH2)m—COOR′ (1)
• wherein R and R′ independently represent a group selected from alkyl groups with 10 carbons and alkenyl groups with 10 carbons;
• and n and m each represent a number of 0 or more and 18 or less, and a total of n and m is 0 or more and 18 or less,
• ROOC—(CH2)p—CH(SO3M)—CH2—(CH2)q—COOR′ (2)
• wherein M represents a cation, and R and R′ independently represent a group selected from alkyl groups with 10 carbons and alkenyl groups with 10 carbons;
• and p and q each represent a number of 0 or more and 18 or less, and a total of p and q is 0 or more and 18 or less,
• wherein the mixture from which the removal of the insoluble component is made comprises the components (S), (B1) and (B2), wherein a mass ratio of the content of the component (B1) to a total content of the components (S), (B1) and (B2), (B1)/(S +B1 +B2), is 0.05 or more and 0.65 or less, and a mass ratio of the content of the component (B2) to the total content of the components (S), (B1) and (B2), (B2)/(S +B1 +B2), is 0.03 or more and 0.26 or less.