| 摘要 |
PROBLEM TO BE SOLVED: To provide a purification method for an epoxy resin, stably decreasing the amount of the hydrolyzable chlorine contained in the epoxy resin by using a simple process, without requiring a water washing step using much water. SOLUTION: The method comprises reacting a crude epoxy resin with a sodium hydroxide aqueous solution, which epoxy resin is prepared by reacting a polyhydric phenol with epihalohydrin in the presence of an alkali catalyst, then, dehydrating under a low temperature condition so that the water content in the reaction system is 0.1-1.0 wt.%, and then, adding an acidic material to the reaction product, to neutralize under the condition that the water content in the reaction system is 0.1-1.0 wt.% and the resin temperature is 40-60°C. COPYRIGHT: (C)2008,JPO&INPIT |
