METHOD FOR PRODUCING POLYACETAL COPOLYMER

摘要

The present invention provides a high-quality polyacetal copolymer by means of a simple process in an economical manner. The present invention includes: a raw material supply step of supplying a raw material including trioxane and the like to a reaction device 1; a polymerization reaction step of setting the polymerization environmental temperature to no more than 100°C until the reaction device conversion rate (the below described D/C) becomes 0.5, and after this carrying out further polymerization; a vaporizing and separating step of vaporizing and separating unreacted monomers from the reaction mixture at an environmental temperature of at least 115°C and less than 140°C; an unreacted monomer re-supply step of supplying the separated monomers to the raw material supply step; and a polyacetal copolymer recovery step for recovering the polyacetal copolymer from the reaction mixture. As a result, the weight ratio D/C of the polyacetal copolymer D with respect to the total supplied monomer C which is stipulated as a sum of a monomer A which is newly supplied to the reaction device and a monomer B which is recovered from the reaction device and re-supplied is at least 0.7, and D/A is at least 0.85.