METHOD FOR RECOVERING N-METHYLPYRROLIDONE

摘要

PURPOSE:To recover N-methylpyrrolidone in high recovery ratio, by distilling an N-methylpyrrolidone-containing solution produced in manufacturing of polyarylene thioether using N-methylpyrrolidone and treating the recovered N-methylpyrrolidone by an air-tight blender equipped with a heater under a specific condition. CONSTITUTION:An N-methylpyrrolidone-containing solution produced in manufacturing of polyarylene thioether using N-methylpyrrolidone as a polymerization solvent is distilled, most of the contained N-methylpyrrolidone is recovered and the residue is recovered as distillation still residue having transportable fluidity. The still residue is put in an air-tight blender equipped with a heater having a vent for high viscosity and treated at 190-310 deg.C temperature in the blender at 50-760Torr for 5min-10hr and the contained N-methylpyrrolidone is recovered through the vent. EFFECT:The concentrated blend after recovery of N-methylpyrrolidone hardly contains N-methylpyrrolidone and can be readily burnt or abandoned.