Patent ID: 9657136
Date: 2017-05-23
CPC Classifications: C08G

Claim:
1. A production method for a polyacetal copolymer with trioxane as a main monomer (a) and a cyclic ether and/or cyclic formal having at least one carbon-carbon bond as a comonomer (b), wherein when producing the polyacetal copolymer, copolymerization is carried out using a heteropoly acid shown by the below General Formula (1) as a polymerization catalyst (c), and the polymerization catalyst (c) is deactivated by adding to a reaction product a carbonate, bicarbonate, or carboxylate of an alkali metal or alkali earth metal or a hydrate thereof (d), and performing a melt kneading treatment, wherein, M M x is an integer from 1 to 10, y is an integer from 6 to 40, z is an integer from 10 to 100, m is an integer of 1 or more, and n is an integer of 0 to 50, and wherein an added amount of the carbonate, bicarbonate or carboxylate of an alkali metal or alkali earth metal or a hydrate thereof (d) with respect to 1 kg of the crude polyacetal copolymer obtained by the copolymerization reaction is 0.006 to 0.34 mEq.