| 摘要 |
PURPOSE:To obtain the titled compound, useful as a surfactant, etc., and having a low to high molecular weight in high purity and yield economically, by oxidizing polyethylene glycol with a gas containing O2 in the presence of a platinum catalyst while increasing the temperature of the reaction system with the progress of the reaction. CONSTITUTION:A polyethylene glycol, expressed by the formula HO(CH2CH2)nH (n is 2-500) and a mixture thereof, and having a polymerization degree of 2-500, preferably in the form of an aqueous solution, is oxidized with a gas containing O2 in the presence of a platinum catalyst under a pressure of 2-6kg/cm<2> at 40-100 deg.C, preferably 40-60 deg.C, while increasing the temperature of the reaction system with the pregress of the reaction to the final temperature of 70-100 deg.C at the completion of the reaction to give the aimed compound expressed by the formula HOOCCH2O (CH2CH2O)n-2CH2COOH and a mixture thereof. The temperature is increased at a temperature satisfying formulaI[T( deg.C) is the reaction temperature; X(%) is reaction rate], preferably formula II. The concentration of the polyethylene glycol in the aqueous solution is preferably 20-80%. |
