METHOD FOR PRODUCING POLYAMIDE RESIN

摘要

A polyamide resin can be produced by polycondensing a polyamide oligomer having a relative viscosity of 1.1 to 1.3 and a water content of 3 mass% or less by melt-kneading the polyamide oligomer in the inside of a cylinder (S) of an extruder. The extruder is provided with open vents (OV1, OV2) and vacuum vents (V1, V2). The open vent (OV1) is provided in the vicinity of a supply port (A3), e.g., above the supply port (A3), and a pressure-reducing element (Y) is provided on the upstream side from the positions of the vacuum vents (V1, V2). The open vent (OV2) is provided in a former stage region (OA) and can become in a pressurized state.