METHOD FOR PRODUCING POLYAMIDE RESIN

摘要

PROBLEM TO BE SOLVED: To polymerize a polyamide resin having a predetermined molecular weight using an extruder without causing process trouble.SOLUTION: A polyamide resin (A) having a relative viscosity of 1.5-3.0 is melted and kneaded using an extruder comprising a co-rotating intermeshing twin screw and having at least one or more vacuum vents VV1, VV2 to obtain a polyamide resin (B) polymerized by polycondensation. A pressure reducing element Y is provided in a part closer to the supply part side than a barrel provided with the vacuum vent VV1 or VV2, and an area in a range of 30-70% of the whole screw length is a vacuum area VA of 300 torr or lower.