Patent ID: 9540485
Date: 2017-01-10
CPC Classifications: B29B,B29C,B29K,C08G,C08L

Claim:
1. A polyamide resin production method for producing a polyamide resin through polycondensation of a polyamide oligomer, the polyamide oligomer comprising a diamine unit containing 70 mol % or more of a diamine unit selected from an aromatic diamine unit represented by the following general formula (I-1) and an alicyclic diamine unit represented by the following general formula (I-2); and a dicarboxylic acid unit containing 50 mol % or more of a dicarboxylic acid unit selected from a linear aliphatic dicarboxylic acid unit represented by the following general formula (II-1) and an aromatic dicarboxylic acid unit represented by the following general formula (II-2), wherein in the production method, the polyamide oligomer having a relative viscosity of from 1.1 to 1.3 and a water content of 3% by mass or less is melt-kneaded to produce the polyamide resin through polycondensation, using an intermeshed co-rotation twin screw extruder having at least one open vent and at least one vacuum vent, and a pressure-decreasing element is provided at a position nearer to the supply section side than a position at which the vacuum vent is provided, and an area of 30% or less of the total screw length is a vacuum area having a pressure of 300 Torr or less in the extruder: wherein, in the general formula (II-1) n indicates an integer of from 2 to 18, and in the general formula (II-2) Ar represents an arylene group.