| 摘要 |
<p>PURPOSE:To recover the titled compound in a form reusable without neutralizing the catalyst, economically in high efficiency, by adding a specific (halogenated) hydrocarbon to a polymer having polyoxytetramethylene group, thereby precipitating and separating the heteropolyacid used as a catalyst. CONSTITUTION:A heteropolyacid (e.g. phosphotungstic acid, etc.) used as a polymerization catalyst and existing in a polymer having polyoxy-tetramethylene group in the molecule (e.g. polyoxytetramethylene glycol) or a mixture of the polymer with an organic solvent, is separated from the polymer by adding a solvent or a solvent mixture comprising a 3-15C hydrocarbon (e.g. n-octane) or a 1-15C halogenated hydrocarbon, etc. to the polymer mixture, thereby separating the heteropolyacid or a phase composed mainly of th-e heteropolyacid from the polymer mixture.</p> |
