申请人:Asahi Kasei Chemicals Corporation
公开号:EP2626345A1
公开(公告)日:2013-08-14
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).
本发明的目的是提供一种分离含有多种可逆反应化合物的混合物的方法,特别是一种从含有异氰酸酯和羟基化合物的混合物中有效分离异氰酸酯的方法,尤其是一种有效分离由N-取代氨基甲酸酯热分解形成的异氰酸酯和羟基化合物的方法。为实现上述目标,可采用一种方法,用多级蒸馏塔分离含有活性含氢化合物(A)和与活性含氢化合物(A)发生可逆反应的化合物(B)的混合物、该方法包括在中间沸点非活性化合物(C)存在的情况下,用多级蒸馏塔蒸馏分离活性含氢化合物(A)和化合物(B),中间沸点非活性化合物(C)的正常沸点介于活性含氢化合物(A)的正常沸点和化合物(B)的正常沸点之间,并且对活性含氢化合物(A)和化合物(B)均无化学活性。