The styrene tar which contains the recovery

摘要

PROBLEM TO BE SOLVED: To efficiently, economically and advantageously recover a nitrophenol- based polymerization inhibitor in a styrene tar without using an acid or an alkali. ;SOLUTION: A styrene tar containing a nitrophenol-based polymerization inhibitor is treated with hot water at 80-160°C, preferably 100-150°C, especially preferably 120-140°C to extract the nitrophenol-based polymerization inhibitor. The back extraction of the polymerization inhibitor in the aqueous phase is then preferably carried out with an aromatic hydrocarbon-based solvent to thereby recover the polymerization inhibitor. Furthermore, the hot water is used in an amount of preferably 20-150 pts.wt., especially preferably 30-140 pts.wt. based on 1 pt.wt. styrene tar. The aromatic hydrocarbon-based solvent is preferably a mixture of ethylbezene with styrene and used in an amount of preferably 0.2-1 pt.wt. based on 1 pt.wt. aqueous phase.;COPYRIGHT: (C)1997,JPO