| 摘要 |
PURPOSE:To selectively remove impurities from a solvent in high efficiency, by adding an epoxy compound to a non-carboxylic acid solvent containing water or an impurity having close boiling point to the solvent to convert the impurity into a monohydroxyl compound and separating the impurity from the solvent by distrillation. CONSTITUTION:A non-carboxylic acid solvent (e.g. gamma-butyrolactone) containing an impurity (e.g. 4-9C carboxylic acid) having active hydrogen and close boiling point to the solvent is added with an epoxy compound (e.g. a glycidyl ether compound) in an amount of preferably >=1 equivalent, especially 1-100 equiva lent based on the existing impurity to convert at least a part of the impurity into a monohydroxyl compound (the boiling point of the produced compound is remarkably different from that of the impurity component having active hydrogen and contained in the solvent). The converted impurity is separated from the solvent by distillation to easily obtain a purified solvent. Since the monohydroxyl compound has high thermal stability, it generates no impurity again by distillation.
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