| abstract |
The invention provides a simple process for producing high-quality thermostable polyacetal copolymer with high polymerization yield, few unstable end parts and low formaldehyde emission. More particularly, when producing polyacetal copolymer, metaformaldehyde is used as a principal monomer, and cyclic ether or cyclic acetal with at least one carbon-carbon bond is used as a comonomer, and specific heteropoly acid is used as a polymerisation catalyst, and specific quaternary ammonium compound for melt blending process into copolymer of reaction product is added, thereby inactivating polymerization catalyst and producing stable polyacetal copolymer with reduced unsteady end group. |