Patent ID: 7897672
Filing Date: 2011-03-01
Classification: C08G

Abstract:
1. A process for continuously producing a polyoxymethylene copolymer comprising a step of melt-kneading a crude polyoxymethylene copolymer at a temperature not lower than the melting point thereof, devolatilizing under reduced pressure formaldehyde gas generated as a decomposition product, subsequently mixing a formaldehyde scavenger containing a hydrazide compound (A) while keeping the copolymer in a molten state and immediately pelletizing the mixture, characterized in that said formaldehyde scavenger is a dispersed solution obtained by slurry-dispersing said (A) in a diluent (B) having a melting point lower than temperature (Ta) within a temperature range not lower than the melting point of (B) and lower than (Ta), wherein said (Ta) is the lower one of the melting point and the decomposition temperature of (A).