Verfahren zur Herstellung von Recyclatpolyolen aus Polyurethanen

摘要

In continuous production of polyols from polyurethane (waste) (PUR) by reaction with polyhydric alcohol (I), especially diol (IA), crushed PUR is mixed with (I/IA) in a separate stage (3) to a touch-dry, pourable mixture, which is stable in storage for several weeks under dry air; reacted in a multi-screw extruder (4) at 170-250[deg]C and elevated pressure not > 50 bar to liquid product; and transferred in liquid form directly from extruder, with continuous stirring, to secondary reaction system (5a, 5b) operating at lower reaction temperature than extruder.