A refining process for removing impurities from 1,3-dimethyl-2-imidazolidinone (DMI) employs a composite salt containing MgO and/or SiO₂ composition moieties and the DMI to be refined is brought into contact with the salt at a temperature in the range of 5 - 180°C. A process for preparing an aromatic polyamide having a high polymerization degree from an aromatic diisocyanate and an aromatic dicarboxylic acid by using as a reaction solvent, DMI purified by the above-mentioned process.
一种从 1,3-二甲基-
2-咪唑烷酮(
DMI)中去除杂质的精制工艺采用了一种含有 MgO 和/或 SiO₂组成分子的复合盐,并在 5 - 180°C 的温度范围内将待精制的
DMI 与该盐接触。用上述工艺提纯的
DMI 作为反应溶剂,用芳香族二
异氰酸酯和芳香族二
羧酸制备具有高聚合度的芳香族聚酰胺的工艺。