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Process for reducing impurity levels in methylene diphenyamines

  • US 5,286,760 A
  • Filed: 10/09/1992
  • Issued: 02/15/1994
  • Est. Priority Date: 10/09/1992
  • Status: Expired due to Fees
First Claim
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1. A process for preparing a reaction product containing methylene di(phenylamine) comprising reacting aniline with an formaldehyde, in the presence of a low level of an acid which is sufficient to catalyze the reaction at an initial and/or condensation stage of said reaction and produce methylene di(phenylamine)intermediates;

  • providing a reaction mixture at the condensation stage with an acid content which is at or below the initial acid level at the end of the condensation stage, and holding reaction mixture at a high temperature which is sufficient to effect a rearrangement of the intermediates to produce a reaction product containing methylene di(phenylamines) and low levels of impurities.

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