Patent ID: 8993709
Filing Date: 2015-03-31
Classification: C08G

Abstract:
1. A process for the preparation of oxymethylene polymers comprising the following steps: a) heterogeneous polymerization, in the presence of a chain transfer agent and an initiator for cationic polymerization, of a mixture comprising b) raising the temperature during the course of the polymerization sufficiently far that a substantially homogeneous polymer melt is present at the end of polymerization prior to deactivation alongside remaining residual monomers, c) deactivating the active polymer chains in a substantially homogeneous phase by feeding a deactivator into the polymer and monomer mixture, d) feeding the deactivated homogeneous polymer mixture prepared in step a) to c) to a hydrolysis zone as a hydrolysis mixture comprising one or more protic solvent(s) and wherein said polymer mixture is subjected to hydrolysis in the presence of protic solvent at a temperature which is higher than the melting point of the polymer mixture prepared in step a) to c); and e) precipitating the hydrolyzed oxymethylene polymer from the solution prepared in step d).