| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for preparing a polyacetal copolymer which can prepare a polymer having excellent thermal stability in a high polymn. yield by using a particular heteropolyacid as a polymn. catalyst to prepare a polyacetal copolymer comprising a trioxane as a main monomer. SOLUTION: A main monomer of a trioxane is copolymerized with a comonomer of a cyclic ether or a cyclic formal having at least one carbon- carbon bond to prepare a polyacetal copolymer. The copolymerization is conducted in the presence of a polymn. catalyst of a heteropolyacid (acid salt) represented by the formula Hx [Mm M'n Ol ].yH2 O (M is one or two center elements selected form P and Si; M' is at least one coordinated element selected from W, Mo, and V; l is 10 to 100; (m) is 1 to 10; (n) is 6 to 40; (x) is an integer of not less than 1; and (y) is 0 to 50). A basic gas as a catalyst deactivator is brought into contact with the resultant polymer to deactivate the catalyst, and the crude polymer as such is then heat-melted without washing. |
