PROCESS FOR PREPARING A POLYAMIDE, A NYLON SALT TO BE USED THEREIN AND A PROCESS FOR MAKING THE SALT Russian patent published in 2019 - IPC C08G69/26 C08G69/28 C08G69/30 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing a granular material of a diammonium dicarboxylate salt, to a granulated salt material, to versions of a method of producing polyamide, to a granulated material of polyamide. Method of producing a granular material of a diammonium dicarboxylate salt is that an aqueous solution or an aqueous suspension is sprayed on a fluidised bed of di-magnesium dicarboxylate salt particles or sprayed in a fluidised bed. Preliminarily heated gaseous medium is passed through fluidized bed with simultaneous evaporation of aqueous medium, which leads to production of granulated material of salt. Aqueous solution contains a diamine or a mixture of diamines and a dicarboxylic acid or a mixture of dicarboxylic acids which are dissolved in an aqueous medium. Aqueous suspension contains a diammonium dicarboxylate salt dispersed in an aqueous medium directly obtained from an aqueous solution containing diamine and dicarboxylic acid, dissolved in an aqueous medium. Obtained granular salt material contains a diammonium dicarboxylate salt. Method of producing polyamide involves direct solid-phase polymerisation of a diammonium dicarboxylate salt, which is said granular salt material. Granular material of polyamide is obtained. In the second version of the method, polyamide is obtained by polymerisation of a diammonium dicarboxylate salt in a liquid state, where said salt contains said granular salt material.

EFFECT: invention reduces amount of fine fraction of particles and formation of deposits in reactor, and also enables to obtain polymer with high output and good characteristics of flowability.

22 cl, 4 dwg, 2 tbl, 4 ex