申请人:MITSUI TOATSU CHEMICALS, Inc.
公开号:EP0032733A1
公开(公告)日:1981-07-29
This invention relates to a process for preparing diphenylmethane dicarbamates and polymethylene polyphenyl polycarbamates by reacting an N-phenyl carbamic acid ester with formaldehyde or a formaldehyde-producing substance in which the reaction is carried out in a substantially homogeneous system by using a ferric halide compound as the catalyst and in which, after completion of the reaction, water or an aqueous solution of a hydrohalogenic acid is added to the reaction mixture and the resulting aqueous phase containing the ferric halide compound is separated and recovered to reuse the catalyst.
本发明涉及一种通过使 N-苯基氨基甲酸酯与甲醛或产生甲醛的物质反应来制备二苯基甲烷二氨基甲酸酯和聚亚甲基聚苯基聚氨基甲酸酯的工艺,在该工艺中,使用卤化铁化合物作为催化剂,在基本上均相的体系中进行反应,在该工艺中,反应完成后,向反应混合物中加入水或氢卤酸水溶液,分离并回收含有卤化铁化合物的水相,以重复使用催化剂、反应完成后,向反应混合物中加入水或氢卤酸水溶液,分离并回收所产生的含有卤化铁化合物的水相,以重复使用催化剂。