METHOD FOR DISTILLING MIXTURES COMPRISING ETHYLENE DIAMINE N- METHYLETHYLENE DIAMINE AND WATER AND MIXTURES OF ETHYLENE DIAMINE AND N-METHYLETHYLENE DIAMINE HAVING A LOW CONTENT OF N-METHYLETHYLENE DIAMINE OBTAINABLE THEREBY

摘要

The present invention relates to a mixture of ethylenediamine (EDA) and N-methy--ethylenediamine (Me-EDA) with a low content ff Me-EDA, which comprises at least 99.5% by weight of ethylenediamine, and wherein the concentration of N-methylethylenediamine is in the range from 0.005 to 0.15% by weight. The present invention further relates to a process for distillative workup of a mixture comprising EDA, Me-EDA and water, by introducing the mixture into a distillation column which is operated at a column top pressure of 10 mbar to 4 bar, wherein the weight ratio of water to ethylenediamine in the mixture used is aX : Y where X is the proportion by weight of water and Y is the proportion by weight of ethylenediamine at the azeotropic point of a binary mixture of water and ethylenediamnee at the column top pressure in question, and a is a real number with a value of 0.9 or more. The present invention further provides a process for preparing a distillable mixture comprising EDA, Me-EDA and water, which is suitable for preparing EDA with a low Me-EDA content.