Zimmer Aktiengesellschaft

Lurgi Zimmer Aktiengesellschaft

Claus Born

Reinhard Wolf

Joachim Seelig

Rudolf Kampf

Stefan Deibert

Jurgen Schiwek

Konrad Wolf

This invention relates to a continuous and efficient method for the manufacture of highly pure caprolactam suitable for the polycondensation of Polyamide 6 (polycaprolactam) from polyamide waste. In particular the invention relates to a method for the manufacture of caprolactam from waste containing polyamides, including the steps a) depolymerisation of the waste containing polyamides, whereby a caprolactam raw material and a flow containing secondary constituents or additives is obtained, b) at least one distillation of the caprolactam raw material, and c) at least one crystallisation of the caprolactam material obtained in step b), by which means caprolactam is obtained, whereby at least part of the caprolactam obtained in step c) with a permanganate number of&#x3c;10000 sec. and a UV transmission of&#x3c;85% is added to the waste containing polyamides before and/or during the depolymerisation.

Method for the manufacture of caprolactam from waste containing polyamides

The invention comprises a process of producing .epsilon.-caprolactam from extract water of polycaprolactam obtained by hydrolytic polymerization, wherein

Process of recovering .epsilon.-caprolactam from PA-6 synthesis extract

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Ingelheim, Germany

Claus Born