| abstract |
(57) Abstract: When purifying (meth) acrylic acid and its ester in a purification column using a nitroso compound, the nitroso compound is converted into a total theory based on the bottom side of the purification column. Characterized in that it is supplied from 70% or less of the number of stages. This is a method for preventing polymerization of (meth) acrylic acid and its ester. The nitroso compound partially decomposes in the purification tower and rises in the tower to effectively suppress polymerization of (meth) acrylic acid and the like. In addition to nitroso compounds, N -An oxyl compound or the like can be used in combination, whereby the polymerization of the gas-liquid phase can be more effectively prevented. |