Patent ID: 7173127
Filing Date: 2007-02-06
Classification: C07D

Abstract:
1. Method for the manufacture of caprolactam from waste containing polyamides, the method comprising: a) depolymerisation of the waste containing polyamides to obtain a caprolactam raw material and, where applicable, a flow containing secondary constituents or additives, b) at least one distillation of the caprolactam raw material to obtain caprolactam material, and c) at least one crystallisation of the caprolactam material obtained in step b) to obtain purified caprolactam relative to the caprolactam raw material, whereby at least part of the purified caprolactam obtained in step c) with a permanganate number of<10000 sec. and a UV transmission of<85% is added to the waste containing polyamides before and/or during the depolymerisation.