公开(公告)号：US20170114176A1

公开(公告)日：2017-04-27

申请号：US15119567

申请日：2014-12-10

Applicant: Polyplastics Co., Ltd.

Inventor： Hiroaki NAKAO ,  Eiji MASUDA

IPC: C08G2/28 ,  C08G2/10 ,  C08G2/06

CPC classification number: C08G2/28 ,  C08G2/04 ,  C08G2/06 ,  C08G2/10

Abstract: A high-quality polyacetal produced by a process including supplying a raw material comprising trioxane, a comonomer capable of copolymerizing with trioxane and a non-volatile protonic acid to a reactor of a continuous stirring/mixing machine type; carrying out a polymerization reaction of the raw material to produce a reaction mixture; vaporizing an unreacted monomer to separate the unreacted monomer from the reaction mixture and supplying the unreacted monomer to the raw material supplying; collecting a polyacetal copolymer from the reaction mixture into a collection unit which is arranged downstream from a discharge port and is adjusted to have a gauge pressure of 0.2 kPa or more; and adding a basic compound to the collected polyacetal and then subjecting the resultant mixture to a melt-kneading treatment to deactivate the non-volatile protonic acid.