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 starting material supply step for supplying a starting material including trioxane and the like to a reaction device (1); a polymerization reaction step for obtaining a reaction mixture by causing the polymerization environmental temperature until the reaction device conversion rate (the belowmentioned D/C) becomes 0.5 to be no greater than 100°C and then further performing polymerization; a vaporizing/separating step for vaporizing/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 for supplying the separated monomers to the starting 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 monomers (C) stipulated as the sum of the monomers (A) newly supplied to the reaction device (1) and the monomers (B) recovered from the reaction device (1) and resupplied is at least 0.7, and D/A is at least 0.85.