A process for preparing at least one polyisocyanate from a solid material w

Abstract

The invention relates to a method for recovering raw materials from polyurethane products, having the steps of: (A) providing a polyurethane product based on an isocyanate component and a polyol component; (B) reacting the polyurethane product with an alcohol in the presence of a catalyst, wherein a first product mixture containing alcohol, polyols, carbamates, and optionally water is obtained; (C) preparing the first product mixture, having the steps of: (C.I) mixing the first product mixture obtained in step (B) with an organic solvent, which can be mixed with the alcohol used in step (B), optionally followed by a separation of solid components, thereby obtaining a second product mixture; (C.II) washing the second product mixture obtained in step (C.I) using an aqueous washing fluid, wherein carbamates contained in the second product mixture are hydrogenated partly while releasing amines and alcohol, and carrying out a phase separation into a first solvent phase, containing the organic solvent used in step (C.I) and polyols, and a first aqueous phase, containing water, alcohol, carbamates, and amines; and (C.III) processing the first solvent phase, thereby obtaining the polyols; and optionally (D) processing the first aqueous phase, thereby obtaining an amine which corresponds to an isocyanate of the isocyanate component.

Dependencies are inferred from the claim text.