| 摘要 |
<p>A method for production of polyoxymethylene homo-or co-polymers by homo-or co-polymerisation of trioxan or additional suitable co-monomers is disclosed, wherein trioxan is firstly produced in a monomer plant, which contains residual monomer and which is degassed in one or more stages to give one or more vapour streams (13, 14), optionally fed to a condenser (K) wherein the condensable components are condensed out to give a condensate (15), recycled into the polymerisation reactor (P) and a gaseous stream (16) containing formaldehyde and a partly degassed polyoxymethylene homo-or co-polymer (17), supplied to an extruder (E) or mixer and mixed with normal additives and processing agents to give a polymer melt (19) with removal of a formaldehyde-containing extruder or mixer exhaust gas (18) from the extruder (E) or mixer, characterised in that the formaldehyde-containing by product streams (14, 16, 18) are directly recycled to the monomer plant from the polymer plant without addition of adjuncts.</p> |
