Sulfonation of isophthalic acid with 60% oleum in the process for synthesising sodium 5 sulfoisophthalic acid dimthyl ester (SIPM) &c. were discussed.

• 提供了以60%25发烟硫酸为磺化剂制备5-磺酸钠间苯二甲酸二甲酯（SIPM）的工艺技术。