METHOD OF PRODUCING POLYAMIDE Russian patent published in 2015 - IPC C08G69/28 C08G69/02 C08G69/26 

FIELD: chemistry.

SUBSTANCE: invention describes a method of producing a polyamide via polycondensation of a diamine component and a dicarboxylic acid component in an intermittent action reaction vessel, which is provided with a partial condenser, in the absence of a solvent, wherein the diamine component includes 70 mol % or more of xylene diamine, which includes 20 mol % or more of para-xylene diamine, and the dicarboxylic acid component contains an aliphatic dicarboxylic acid selected from succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid, wherein the method includes the following steps (1)-(3): (1) loading the dicarboxylic acid component into the reaction vessel and raising internal pressure in the reaction vessel to 0.2 MPa (manometric) or higher; (2) continuously or periodically adding the diamine component to the dicarboxylic acid component until the molar ratio (B/A) of the diamine component (B) to the loaded dicarboxylic acid component (A) reaches 0.60, while keeping internal pressure in the reaction vessel at 0.2 MPa (manometric) or higher and keeping the entire reaction system in a liquid state; and (3) reducing internal pressure in the reaction vessel to a level below 0.2 MPa (manometric) while the molar ratio (B/A) of the diamine component (B) to the loaded dicarboxylic acid component (A) is in the range of 0.60 to 0.95, while keeping the entire system in a liquid state and continuously or periodically adding the diamine component to the dicarboxylic acid component.

EFFECT: obtaining a diamine with improved quality properties.

7 cl, 8 ex