LIQUID-LIQUID SEPARATION METHOD AND (METH)ACRYLATE PRODUCTION METHOD

PROBLEM TO BE SOLVED: To provide a liquid-liquid separation method which can perform the separation of an upper layer and an under layer with a high accuracy, can improve the qualities, such as those about color tone and impurities, of an obtained product, and can quickly perform the separation, improving productivity; and a (meth)acrylate production method using the separation method. SOLUTION: The liquid-liquid separation method is performed by putting a (meth)acrylate having a lower specific gravity and an aqueous sodium hydroxide solution having a higher specific gravity into a neutralization tank 14, stirring them, leaving them at rest, separating them into an upper layer and an under layer, extracting the under layer liquid, and separating the (meth)acrylate from a water layer. In this case, the position of an interface 21 between the upper layer and the under layer is measured with an interface meter 20 and when the position of the interface 21 becomes fixed, the under layer liquid is extracted. In addition, the specific gravity of the extracted under layer liquid is measured with a gravimeter 22 and when the specific gravity becomes fixed, the extraction is stopped and the liquid-liquid separation is ended. COPYRIGHT: (C)2008,JPO&INPIT