METHOD FOR PRODUCING PURIFIED POLYALKYLENE GLYCOL AND PURIFIED POLYALKYLENE GLYCOL

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a purified polyalkylene glycol, with which low-molecular compounds such as water, ethylene glycol, diethylene glycol, a lower aldehyde, etc., are removed from a crude polyalkylene glycol in a large amount.;SOLUTION: A polyethylene glycol having 200-10,000 molecular weight is defoamed and subjected to thin film evaporation so that impurities having molecular weight not more than the molecular weight of diethylene glycol are removed to give a purified polyalkylene glycol. The temperature of the defoaming is ≥100°C and ≤220°C and the pressure is ≥13.3 Pa and ≤4,000 Pa. The temperature of the thin film evaporation is ≥100°C and ≤250°C and the pressure is 1.33 Pa and ≤13.3 Pa.;COPYRIGHT: (C)2005,JPO&NCIPI