METHOD OF PRODUCING POLYAMIDE Russian patent published in 2017 - IPC C08G69/28 

FIELD: chemistry.

SUBSTANCE: polycondensation of the diamine component and the dicarboxylic acid component is carried out in a batch reactor. As a diamine component, a mixture of xylylenediamines containing, at least, 40 mol % of p-xylylenediamine is used. The diamine component is added dropwise to the dicarboxylic component, which is maintained in a melt state by heating it to a temperature below its melting point, at a pressure of 0.1 MPa of excess or more. The reaction mixture is maintained in a melt state. The temperature of the reaction mixture is maintained at not more than 255°C until the molar ratio of the diamine component/dicarboxylic acid component for the reaction mixture reaches 0.8. The temperature of the reaction mixture at the end of the dropwise addition of the diamine component is controlled so that it has a value not lower than the melting point of polyamide. The resulting polyamide has a melting point in the range of 255°C to 285°C.

EFFECT: improved shades and a good quality.

3 cl, 2 tbl, 8 ex