PURPOSE: To readily obtain qualities required for producing a high-molecular weight polymer having excellent water solubility, by treating the ester with active carbon, in purifying an acrylic acid dialkylaminoethyl ester providing a polymer useful as a cationic high polymer flocculant, etc.
CONSTITUTION: An acrylic acid dialkylaminoethyl ester or methacrylic acid dialkylaminoethyl ester shown by the formula (R1 is H or methyl; R2 and R3 are 1W2C alkyl) is treated with active carbon and purified. The active carbon treatment method is carried out by either of continuous method wherein a treatment solution is made to flow through a column filled with active carbon or batch method wherein the solution is treated with active carbon and the active carbon is separated and removed by filtration, centrifuging, etc. The amount of the active carbon used is preferably 0.1W5wt% based on the compound shown by the formula. The treatment temperature is preferably in a range of 0W100°C.
YAMAUCHI ATSURO
MURANAKA HIDEKAZU
