METHOD OF PREPARING ISOCYANATES Russian patent published in 2001 - IPC

FIELD: chemical industry. SUBSTANCE: isocyanates are prepared by reacting primary amine with phosgene dissolved in isocyanate/phosgene at temperatures from 60 to 180 C and pressure from 1 to 30 bar at phosgene to amine molar ratio from 4:1 to 1:1. Isocyanate solvent is free from solid substance and has value of hydrolyzable chlorine of less than 2%. Method makes it possible to prepare isocyanates with yield of up to 100% using small-size equipment. EFFECT: more efficient preparation method. 4 cl, 1 dwg, 10 ex