| 摘要 |
A method of producing a polyamide includes (i) polycondensating a polyamide precursor containing a salt made from a dicarboxylic acid and a diamine under pressure in a pre-polymerization tank to obtain a prepolymer, and (ii) highly polymerizing the prepolymer with an extruder, wherein when the prepolymer in a molten state which is obtained in the step (i) is fed, by a pump, to the low-pressure extruder from the pre-polymerization tank through a discharge side pipe disposed downstream of the pump, the prepolymer is fed such that the length L [cm] of the discharge side pipe and the linear velocity of discharge v [cm/s] of the prepolymer by the pump satisfy the relationship expressed by the equation, 0.1 [s]≦L/v<10 [s]. |
