METHOD OF PRODUCING POLYAMIDE

摘要

The present invention provides a method for producing a polyamide having a melting point of 255oC or higher by polycondensing a xylylenediamine mix containing paraxylylenediamine as a diamine component and a dicarboxylic acid component using a batch reactor. The method is characterized in that the diamine component is added dropwisely to the dicarboxylic acid component, which has been heated to a temperature equal to or higher than the melting point thereof and therefore is kept in a molten state, under a pressure of 0.1 MPaG or more while keeping the resultant reaction mixture in a molten state, wherein the temperature of the reaction mixture is kept at 255oC or lower until the molar ratio in the reaction mixture (i.e., (the diamine component)/(the dicarboxylic acid component)) reaches 0.8 and the temperature of the reaction mixture after the completion of the dropwise addition is adjusted to a temperature equal to or higher than the melting point of the polyamide. The method enables the production of a polyamide that has an improved hue and is advantageous with respect to quality.