Process for preparing at least one polyisocyanate

Abstract

The present invention relates to a process for preparing at least one polyisocyanate R(—NCO)x, the process comprising preparing a mixture R1 comprising at least one polyamine R(—NH2)x, with x=2 or more, in a first reaction zone Z1; passing at least a portion P1 of the mixture R1, P1 comprising R(—NH2)x, into a storing device D1 and storing P1 in D1 for a period of time Δt1; removing, after storing for Δt1, at least a portion P2 of P1, P2 comprising R(—NH2)x, from D1; passing P2 into a reaction zone Z2; and reacting, in Z2, R(—NH2)x comprised in P2 with phosgene, obtaining a mixture R2 comprising the at least one polyisocyanate R(—NCO)x; wherein Δt1 is in the range of from 1 minute to 7 d.

Dependencies are inferred from the claim text.