Patent ID: 8354495

Claim:
A process for the preparation of oxymethylene polymers via polymerization of at least one monomer that forms —CH 2 —O— units, if appropriate in combination with at least one comonomer copolymerizable therewith having at least one C—C bond, and also in the presence of a chain transfer agent and of an initiator for cationic polymerization, which comprises carrying out the polymerization in a first phase in a heterogeneous polymerization mixture and, following this, carrying out further polymerization in a second phase in a homogeneous polymerization mixture, and wherein, at the end of the second phase polymerization, a deactivator is added for terminating polymerization, wherein from about 10% to about 70% of the monomer is converted to the oxymethylene polymer during the first phase heterogeneous polymerization.