PROCESS FOR CONTINUOUS PRODUCTION OF POLYMETHYLENE POLYPHENYL POLYAMINE

摘要

Disclosed is a process for continuous production of a polymethylene polyphenyl polyamine which can produce a polymethylene polyphenyl polyamine continuously by reacting aniline and formaldehyde in the presence of a hydrochloric acid catalyst. The process comprises: (A) a first condensation step in which aniline in an amount of 80-95% by mass relative to the total amount to be charged and a portion of the total amount of formaldehyde to be charged are reacted with each other in the presence of a hydrochloric acid catalyst under such conditions where the hydrogen chloride/aniline ratio (by mole) is 0.99 or less; (B) a second condensation step in which the reaction solution yielded in the first condensation step is mixed with the remainder of formaldehyde to react them with each other; and (C) an isomerization step in which the reaction solution yielded in the second condensation step is mixed with aniline in an amount of 5-20% by mass relative to the total amount to be charged to cause an isomerization reaction between them. According to the process, it becomes possible to produce a polymethylene polyphenyl polyamine which has a reduced N-methyl substance content to the similar level to that in a batch-wise process and contains methylene diphenyl diamine in an amount similar to that in a batch-wide process.