METHOD FOR PURIFYING HIGH MOLECULAR WEIGHT POLYOXYALKYLENE DERIVATIVE

PROBLEM TO BE SOLVED: To provide a method for purifying high molecular weight polyoxyalkylene derivative producing a high-purity and high-molecular weight polyoxyalkylene derivative by reducing impurities differing in the number of hydroxy groups in a molecule contained in the main component. SOLUTION: The purifying method for separating the impurity differing in the number of hydroxy groups, from the specified polyoxyalkylene derivative having a molecular weight of 8,800 to 100,000 comprises the following processes (A), (B), (C) and (D): (A) dissolving the polyoxyalkylene derivative by using a non-protonic organic solvent having a weight of 5 times or more of the weight of the polyoxyalkylene derivative to prepare a solution; (B) adding an adsorbent comprising an oxide containing at least one of aluminum and silicon, in an amount of 0.5 to 5 times by weight the amount of the polyoxyalkylene derivative to the solution, to prepare slurry; (C) stirring the slurry at 25°C or higher; and (D) recovering the polyoxyalkylene derivative from the slurry. COPYRIGHT: (C)2011,JPO&INPIT