Process for preparing a diamine/dicarboxylic acid salt

摘要

The present invention also relates to a process for preparing a diamine/dicarboxylic acid salt wherein the dicarboxylic acid comprises an aromatic dicarboxylic acid and is provided in a powder form; the diamine is provided in a liquid form gradually dosed to the dicarboxylic acid powder, while keeping the dicarboxylic acid powder in constant movement; the processing temperature is above 0° C. and below the boiling temperature of the diamine and the melting temperature of the acid and the salt, and the reaction mixture comprises at most 5 wt. % of water. The present invention also relates to an anhydrous diamine/dicarboxylic acid salt obtainable by the process according to invention, or any embodiment thereof as described above.

主权项

1. A process for preparing a diamine/dicarboxylic acid salt comprising the steps of:
(i) forming a reaction mixture by contacting a diamine liquid with a dicarboxylic acid powder comprising an aromatic dicarboxylic acid having a particle size distribution, measured by the method according to ISO 13320, with a d10 of at least 15 μm and a d90 of at most 1000 μm and with a median particle size (d50) in a range of 40-500 μm, and (ii) allowing the diamine and the aromatic dicarboxylic acid in the reaction mixture to react to form a diamine/dicarboxylic acid salt, wherein step (i) comprises the steps of: (a) gradually dosing the diamine liquid to the aromatic dicarboxylic acid powder , while keeping the aromatic dicarboxylic acid powder in constant movement, and thereafter (b) keeping the reaction mixture in constant movement for a time period directly following completion of the dosing; wherein steps of (a) and (b) are carried out at a temperature above 0° C. and below all of the following: the boiling temperature of the diamine and the melting temperatures of the dicarboxylic acid, the diamine/dicarboxylic acid salt and any intermediate reaction product, and wherein the reaction mixture in steps (a) and (b) comprises at most 5 wt. % of water, relative to the total weight of the diamine and dicarboxylic acid.