CONTINUOUS POLYAMIDE PRODUCTION PROCESS, METHOD OF PREPARING HIGH- MOLECULAR POLYCAPROAMIDE, AND POLYCAPROAMIDE WITH MOLECULAR WEIGHT 3000-14000 Russian patent published in 2000 - IPC

FIELD: polymer production. SUBSTANCE: polyamides are prepared from mixture of at least one lactam and water under polyamide- forming conditions. In the first step, mixture containing 0.5 to 7 wt % water is heated to 220-310 C at pressure allowing reaction mixture to be single-phase and liquid to achieve degree of polymerization at least 85%, after which pressure is adiabatically thrown off and polymerization further proceeds at 215 to 300 C. For example, first-step polycaproamide with molecular weight 3000 to 9000 (on the base of end group content) and polycaproamide with molecular weight 3000 to 14000 are described. High-molecular polycaproamide is prepared by solid-phase polycondensation of low-molecular one upon heating. EFFECT: enhanced process efficiency. 12 cl, 4 tbl, 5 ex