Patent ID: 9260563
Filing Date: 2016-02-16
CPC Classification: C08G

Claim Text:
1. A method of producing polyamide, comprising: (1) charging a dicarboxylic acid component into a batchwise reaction tank equipped with a partial condenser and increasing an inner pressure of the reaction tank to 0.2 MPaG or higher; (2) adding a diamine component to the dicarboxylic acid component continuously or intermittently until a molar ratio (B/A) of the diamine component (B) to the charged dicarboxylic acid component (A) reaches 0.60, while maintaining the inner pressure of the reaction tank at 0.2 MPaG or higher and maintaining a whole reaction system in a fluid state; (3) reducing the inner pressure of the reaction tank to 0.1 MPaG or lower and atmospheric pressure or higher during the time when the molar ratio (B/A) of the diamine component (B) to the charged dicarboxylic acid component (A) is within a range of from 0.60 to 0.95, while maintaining the whole reaction system in a fluid state and adding the diamine component to the dicarboxylic acid component continuously or intermittently; and (4) after completing the adding in (3), maintaining the inner pressure of the reaction tank at the time when the adding in (3) is completed for from 5 minutes to 3 hours, while maintaining the whole reaction system in the fluid state, wherein the diamine component comprises 70 mol % or more of a xylylenediamine, and the xylylenediamine comprises 20 mol % or more of p-xylylenediamine, and polycondensation of the diamine component and the dicarboxylic acid component is conducted in the absence of a solvent.