间苯二甲酸二甲酯-5-磺酸钠制备工艺改进

Improvement on the Synthetic Process of Sodium-5- Sulfoisophthalic Acid Dimethyl Ester

以间苯二甲酸 ( IPA)、SO3的质量分数为 5 0 %发烟硫酸 ( SO3· H2 SO4 )、CH3OH、Na OH为原料 ,经磺化、酯化、中和反应合成间苯二甲酸二甲酯 - 5 -磺酸钠 ( SIPM)。运用正交试验设计 ,考察了上述反应过程中温度、时间、原料配比对 SIPM收率的影响 ,优化了 SIPM的合成工艺条件。结果表明 :磺化反应温度 1 85℃、时间 5 h,n( IPA)∶ n( SO3) =1∶ 1 .1 ;酯化反应温度 76℃ ,酯化时间 5 h,n( IPA)∶ n( CH3OH) =1∶ 6;中和反应温度 2 5℃ ,m( IPA)∶ m(母液 ) =1∶ 8为反应最佳条件。此条件下 SIPM平均收率为 78.7% ,纯度 99.5 %。

Sodium 5 Sulfoisophthalic acid dimethyl ester(SIPM) was synthesized from isophthalic acid (IPA) and 50 % oleum. The optimal reaction conditions were determined by orthogonal design method.In sulfonation reaction, the ratio of IPA to SO 3 mol was 1∶1.1,the reaction temperature was 185 ℃ and reaction time was 5h; In esterfication reaction, the ratio of IPA to CH 3OH(mol) was 1∶6, the reaction temperature was 76 ℃ and reaction time was 5h;In neutralization reaction, the reaction temperature was 25 ℃ and the ratio of IPA to mother liquor(mass) was 1∶8. The total yield and purity of the product reached 78.7 % and 99.5 %, respectively.