FIBER-FORMING POLYCAPROAMIDE PRODUCTION AND THREAD PRODUCTION PROCESSES Russian patent published in 2003 - IPC

FIELD: polymer materials. SUBSTANCE: caprolactam is subjected to hydrolytic polymerization until state close to equilibrium is attained, resulting polymerization product is cooled, then heated to 170-190 C and dried, while simultaneously low-molecular compounds are eliminated. Melt of prepolymerizate is prepared at temperature by 1-15 C inferior to melting temperature of polymer and this temperature is maintained until degree of conversion of caprolactam into prepolymer is close to equilibrium value. Partial pressure of water vapor over the melt is maintained within a range of 100-755 mm Hg and product is kept at the same temperature until required molecular weight is obtained. Thread is manufactured from obtained polycaproamide melt. EFFECT: enabled production of polycaproamide with specified molecular weight and uniform composition, improved environmental condition. 2 cl, 1 tbl, 3 ex