| 摘要 |
PROBLEM TO BE SOLVED: To obtain an excellent II type strong basic anionic exchanger by allowing a weak basic anionic exchanger to react with ethylene oxide at a specific temp. and a specific pH. SOLUTION: The weak basic anionic exchanger (starting material) is suspended in water in a form of tertiary amine by mixing. In such a case, water is previously heated before the starting material is added or the starting material is suspended in water and after that heated to a reaction temp. Next, ethylene oxide is introduced step by step or preferably introduced as continuously as possible in a rate enabling the control of the temp. to 70-75 deg.C. During this time, the pH is continuously controlled by adding an adequate inorganic strong acid such as sulfuric acid, phosphoric acid, hydrochloric acid or an acid having pka<2 more accurately through the whole reaction process to keep pH 7-11, preferably 8-10. |
