RO117799B1 - Process and installation for preparing poly-epsilon-caprolactam as bars and plates using anionic polymerization - Google Patents

Abstract

The invention relates to a process and an installation for preparing poly-epsilon-caprolactam as bars and plates using anionic polymerization, said bars and plates being employed in manufacturing various products, such as: toothed wheels, bearings, rollers, sealing gaskets for high pressure conditions, components for vehicle or railway joints, etc. According to the invention, the process consists in polymerizing the anhydrous epsilon-caprolactam by initiation with metal natrium at a gravimetric ratio in relation to the epsilon-caprolactam ranging from 200 to 600 ppm, at a temperature ranging from 70 to 95°C, followed by the supply of the 2,4-toluylene-diisocyanate catalyst, at a gravimetric ratio in relation to the reaction mass ranging from about 1,000 to about 3,500 ppm, at a temperature ranging from 110 to 140 °C and by the feeding of the reaction mass into heated moulds for 10...12 hours. The resulting polymer, having a density of about 1.15 g/cm3, a fracture strength of at least 650 daN and an elongation at fracture of at most 50%, is removed from the mould at a temperature of 70°C. The claimed installation comprises a reactor, a static mixer, some electrically heated drying chambers where some metal moulds are introduced, the roughness thereof on the prepolymer-polymer contact surface being of 0.2...1.5, and hydraulic closing means.