METHOD FOR PRODUCTION OF COPOLYAMIDES Russian patent published in 1997 - IPC

FIELD: production of synthetic copolymers. SUBSTANCE: method is carried out by two-stepped high temperature copolymerization of mixture of ε-caprolactam (its quantity being 0.1-70 mass parts) with lauryl lactam (its quantity being 0.1-60 mass parts) and with ground wastes of nylon production (their quantity being 20-80 mass parts). Relative viscosity of mentioned above nylon being prepared on the base of polyhexamethylene adipamide is 2.0-2.75 at 20 C in sulfuric acid. The first step of copolymerization is carried out at 240-290 C and at pressure 1-20 atm, the second step takes place at 250-280 C and at pressure 0.001-1 atm. EFFECT: improves efficiency of the method.