| 主权项 |
1. A polyamide resin production method for producing a polyamide resin through polycondensation of a polyamide oligomer using an extruder including an intermeshed co-rotation twin screw within a cylinder, the polyamide oligomer comprising: a diamine unit comprising 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 comprising 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),
the production method comprising supplying the polyamide oligomer having a relative viscosity of from 1.1 to 1.3 and a water content of 3% by mass or less from a supply port into the cylinder and melt-kneading the polyamide oligomer in the cylinder to produce the polyamide resin through polycondensation, the extruder comprising an open vent (1), an open vent (2), and a vacuum vent, the open vent (1) being arranged at at least one of a position above the supply port or a position on an upstream end side with respect to a position of the supply port in the cylinder, the extruder further comprising a pressure-decreasing element arranged on an upstream side with respect to a position of the vacuum vent, the open vent (2) being arranged on a side downstream with respect to the position of the supply port in the cylinder and upstream with respect to a position of the pressure-decreasing element, the open vent (2) being brought into a pressurized state, an area of 50% or less of a total screw length of the extruder comprising a vacuum area at 300 torr or less:wherein, in the general formula (II-1), n represents an integer of from 2 to 18, and in the general formula (II-2), Ar represents an arylene group. |
