METHOD FOR CONTINUOUSLY PRODUCING OXIDIZED CYCLIC PHENOL SULFIDES

The present invention discloses a method for continuously producing an oxidized cyclic phenol sulfide which comprises the continuous steps of reacting a para-alkyl phenol compound as a raw material with 1.7 to 2.5 molar equivalent of sulfur and 0.25 to 0.75 molar equivalent of an alkali metal reagent per 1 mol of the phenol compound (the first step); and oxidizing a cyclic phenol sulfide of the formula (2) produced by the above reaction with an oxidizing agent(s) in the same reactor as that of the first step and without taking the cyclic phenol sulfide out of the reactor; wherein R represents a straight or branched alkyl group having 1 to 6 carbon atoms, and m is an integer from 4 to 8, to obtain an oxidized cyclic phenol sulfide of the formula (3) (the second step): wherein R represents a straight or branched alkyl group having 1 to 6 carbon atoms, m is an integer from 4 to 8, and n is 1 or 2.