Patent Number: 6,169,164

Title: Process for preparing polyoxymethylene molding compositions of improved quality

Abstract: A process for the cationically initiated preparation of oxymethylene copolymers in which, after the polymerization and after comminution of the crude polymer in a grinding assembly a portion of the deactivation suspension comprising the ground crude polymer is removed downstream of the grinding assembly and fed back to the process upstream of the grinding assembly. The return procedure predominantly reduces the proportion of oversize while the proportion of undersize rises only insignificantly. The treated crude polymer also has a lower proportion of unstable chain ends.

Inventors: Muck; Karl-Friedrich (Wiesbaden, DE), Roschert; Horst (Ober-Hilbersheim, DE), Endres; Joachim (Langen, DE), Kroll; Juergen (Weiterstadt, DE), Hensl; Rainer (Frankfurt, DE)

Assignee: Ticona GmbH

International Classification: C08J 3/12 (20060101); C08L 59/00 (20060101); C08L 59/04 (20060101); C08F 006/00 ()

Expiration Date: 01/02/2018