Process for the manufacture of a tri-substituted triazine stabilizer

Abstract

A staged process is disclosed for forming a tri-substituted triazine ring in which the substituents are cyclic amines referred to as hindered amines. A prior art process for making such amines in a reaction mixture of aqueous and organic phases has been modified to produce a stabilizer with desirable whiteness, at the same time avoiding the loss of the cyclic amine reactant which is water-soluble. Conversion of the amine to yield at least 90% of the tri-substituted product having at least 90% purity allows the reaction to be commercially significant despite the high cost of the reactants. The staged process is preferably conducted in two sequences in two reactors, with an intermediate step in which the aqueous saline and basic solution from the first sequence is withdrawn. In the first sequence, a mono-chloro intermediate ('MCI') is formed at ambient temperature, but below 100.degree. C. to yield a colored solution. Flowing only the organic phase to the second reactor which must be pressurized, allows use of an economical reactor. In the second sequence, preferably in a separate reaction zone, reacting 3 moles of MCI with no more than 3.5 moles of a third amine, yields the tri-substituted product which is formed at below 200.degree. C. but in excess of 125.degree. C. Only a small portion of the molar excess of amine used in the second sequence need be discarded. The time required to run the reaction in two stages is less than required to run it in a single sequence. Further saving in time is effected by using a phase transfer catalyst.