摘要 |
An object of the present invention is to provide the separation of a mixture containing plural types of reversibly reacting compounds, especially, a method for efficiently separating an isocyanate from a mixture containing the isocyanate and a hydroxy compound, particularly, a method for efficiently separating an isocyanate and a hydroxy compound that form by the thermal decomposition of an N-substituted carbamic acid ester. The object is attained by a method for separating, with a multi-stage distillation column, a mixture containing an active hydrogen-containing compound (A) and a compound (B) that reversibly reacts with the active hydrogen-containing compound (A), the method comprising distillation-separating the active hydrogen-containing compound (A) and the compound (B) with the multi-stage distillation column in the presence of an intermediate-boiling-point inactive compound (C) that has a normal boiling point between a normal boiling point of the active hydrogen-containing compound (A) and a normal boiling point of the compound (B) and is chemically inactive for both of the (A) and the compound (B). |