Patent ID: 7381788
Filing Date: 2008-06-03
Classification: B29B,C08G

Abstract:
1. A continuous production method of a polyamide, comprising continuously producing the polyamide by melt polymerization using a multistage polymerization reaction apparatus, wherein a self-cleaning horizontal twin-screw reaction apparatus is used as a final polymerization reaction apparatus constituting the multistage polymerization reaction apparatus, wherein the final polymerization is effected while performing an operation of purging inert gas inside the final polymerization reaction apparatus or while performing two or three operations selected from the group consisting of an operation of purging inert gas inside the final polymerization reaction apparatus, an operation of vacuating the final polymerization reaction apparatus, and an operation of adding an end group adjusting agent into the final polymerization reaction apparatus, and wherein the melt viscosity of the polyamide is controlled by continuously measuring the melt viscosity of the polyamide at an outlet of the final polymerization reaction apparatus by a viscometer and automatically controlling at least one operation amount selected from the group consisting of the amount of the inert gas purged, the vacuum degree and the amount added of the end group adjusting agent corresponding to said operations so that the measured viscosity value becomes a value within a previously set definite range.