Production of oxymethylene (co)polymers for molding, including specified homopolymers, involves heterogeneous polymerization of monomer in presence of formaldehyde acetal and cationic initiator and deactivation in basic homogeneous phase

摘要

Production of oxymethylene homopolymers (I) with 2 terminal alkyl groups and 500 or more oxymethylene groups comprises (i) heterogeneous polymerization of a monomer forming oxymethylene units in the presence of a formaldehyde acetal and a cationic polymerization initiator and (ii) deactivation of the initiator and/or the active polymer chains by treating the polymer from stage (i) in homogeneous phase with an aprotic solvent, which is basic and/or contains a dissolved base. Oxymethylene homopolymers with specified properties are claimed per se. Production of oxymethylene homopolymers of formula (I) comprises (i) heterogeneous polymerization of a monomer forming -CH 2-O- units in the presence of a formaldehyde acetal and a cationic polymerization initiator and (ii) deactivation of the initiator and/or the active polymer chains by treating the polymer from stage (i) in homogeneous phase with an aprotic solvent, which is basic and/or contains a dissolved base: R 1-(O-CH 2) n-O-R 2 (I); R 1, R 2 independently : alkyl groups; n : 500 or a larger integer . Independent claims are included for (1) production of oxymethylene copolymers by similar heterogeneous polymerization and deactivation steps; (2) oxymethylene homopolymers with specified properties.