POLYAMIDE PRODUCTION PROCESS Russian patent published in 2005 - IPC

FIELD: polymer production.

SUBSTANCE: invention provides continuous process for production of polyamides from dicarboxylic acids and diamines. Process comprises several consecutive stages. Aqueous solution containing dicarboxylate and diammonium ions at molar ratio (0.99-1.01):1, preferably (0.995-1.005):1 is first passed to condensation installation operated under temperature and pressure conditions allowing condensation of primary dicarboxylate and diammonium ions. First condensation product stream not corresponding to required condensation level is withdrawn and then is fed stream of initial reactants with high content of terminal acid groups and high content of terminal amino groups mixed in the same installation or in different installations. Mixing of two streams and condensation are carried out in the same installation or in different installations. Stream of final product produced in condensation operation is withdrawn. Intake of at least one initial streams is controlled from the result of analysis of quantitative content of terminal amino groups and acid groups in condensation medium or in leaving stream so that these quantitative contents and/or their ratio were maintained within a range between two specified values. Invention allows (i) realization of embodiment comprising initiation of the direct amidation process based on the aqueous solution of monomers in stoichiometric proportions and (ii) achievement of continuous conditions allowing standardization of the points of stoichiometry measurements in near infrared region minimizing risk of non-standard polymer formation.

EFFECT: optimized process conditions.

4 dwg, 3 ex