PURPOSE:To efficiently deash a polybutadiene solution resulting from polymerization by adding water to the solution and allowing this mixture to stand in such a temperature range as to cause phase separation to thereby separate an aqueous layer from the polymer solution. CONSTITUTION:Water is added to a polybutadiene solution (a) resulting from polymerization. This mixture is then allowed to stand in such a temperature range that the water-containing polybutadiene solution separates into polybutadiene-deficient layer and a polybutadiene-rich layer. Thus, the mixture is allowed to separate into an aqueous layer and a polybutadiene solution layer. Subsequently the aqueous layer is removed to deash the solution (a). The temperature of the water to be added is preferably not lower than ordinary temperature. The amount of the water is preferably in the range of from 5-100vol.% based on the amount of the solution (a). Agitation for mixing the water and the solution (a) is preferably performed at or above the critical temperature which is the temperature at which the water-containing polybutadiene solution separates into a polybutadiene-deficient layer and a polybutadiene-rich layer.
展开▼
