PRODUCTION OF OXYMETHYLENE COPOLYMER

摘要

PURPOSE:To obtain the titled polymer having improved thermal stability, by copolymerizing trioxane with a cyclic ether, supplying the crude copolymer to an extruder having plural vent ports and two or more screws and kneading the copolymer with a kneading disk paddle between said vent ports. CONSTITUTION:Trioxane is copolymerized with a cyclic ether having C-C bond in the molecule (e.g. ethylene oxide), and the obtained crude oxymethylene copolymer is supplied to an extruder having plural vent ports and two or more screws through the raw material feeding port 1. The fed copolymer is kneaded with the kneading disk paddle attached to the extrusion shaft between the first vent port 2 and the second vent port 3 to effect the decomposition of the unstable terminal of the oxymethylene copolymer. The gaseous decomposition product is discharged from the vent port to obtain the objective stabilized copolymer.