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Method for the production of methylenedi(phenylamine and methylenedi(phenyl isocyanate)

  • US 6,433,219 B1
  • Filed: 09/08/2000
  • Issued: 08/13/2002
  • Est. Priority Date: 02/07/1998
  • Status: Expired due to Term
First Claim
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1. A process for preparing methylenedianiline comprising reacting aniline with formaldehyde in the presence of an acid catalyst, further comprising, in a semicontinuous process, introducing said aniline with or without said acid catalyst, feeding formaldehyde with or without acid catalyst through a mixing element into a circuit in which aniline with or without acid catalyst and with or without previously added formaldehyde is circulated and, after feeding in at least 50% of the total amount of formaldehyde to be fed in, heating the reaction mixture to a temperature above 75°

  • C.

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