PRODUCTION OF ALIPHATIC ALCOHOL ETHOXYLATE

摘要

PURPOSE:To readily obtain the title substance, useful as various detergents and having a narrower addition molar distribution, by extracting an aliphatic alcohol ethoxylate with CO2 in a supercritical or pseudocritical state as an extracting agent. CONSTITUTION:Ethylene oxide is added to an aliphatic alcohol in the presence of an acidic or basic catalyst to provide the title substance having an ethylene oxide addition molar distribution. The resultant substance is then extracted with CO2 in a supercritical or pseudocritical state as an extracting agent to afford the title substance having a narrower addition molar distribution. The supercritical state refers to a state in which the CO2 is kept at a temperature under a pressure of >=31 deg.C critical temperature and >=73atm critical pressure. The pseudocritical state refers to a state in which the CO2 is kept at >=20 deg.C under >= the saturation vapor pressure thereof at the temperature and-other than the critical state. Since the CO2 is not heated at high temperatures by the above-mentioned method, there is no fear of coloring or degradation and deterioration and the ash content is low.