Basf Aktiengesellschaft

Ernst Deuker

Hugo Fuchs

Uwe Brand

Ludwig Schuster

Gerald Neubauer

Elmar Frommer

Hermann Graf

Stefan Wolff

Klaus Kartte

Ruediger Schmitz

Jozef Oostvogels

Serge Wack

Emile DeDecker

Richard Hardt

A process for decoloring polyisocyanates containing isocyanurate and uretdione groups comprises treating the demonomerized polyisocyanates containing isocyanurate and uretdione groups with oxygen.

Decoloration of polyisocyanates containing isocyanurate and diretdione

Reaction mixtures obtained by Beckmann rearrangement of cyclohexanone oxime with sulfuric acid or oleum are neutralized by a process which comprises the following steps:

Neutralization of reaction mixtures obtained by Beckman rearrangement of

Water-immiscible solvents are removed from offgases containing same by washing with water-containing caprolactam.

Removal of water-immiscible solvents from offgases containing same

In a process for continuously extracting caprolactam from an aqueous solution, containing caprolactam and its oligomers, with organic solvents, by introducing the aqueous solution into the upper part of an extraction zone and organic solvents into the lower part, and taking off a solution of caprolactam in organic solvents at the upper end and an aqueous phase containing caprolactam oligomers at the lower end, the improvement that liquid aromatic hydrocarbons are used and the extraction is carried out at a pH of from 2.0 to 6.0.

Continuous extraction of caprolactam from an aqueous solution containing

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Gruenstadt, Germany

Ernst Deuker