METHOD FOR PRODUCING 3,3',5,5'-TETRAALKYL-4,4'-BIPHENOL

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a tetraalkylbiphenol (TABP) capable of repeatedly performing the recovery and reuse of unreacted dialkylphenol (DAP) and advantageous from industrial viewpoint. SOLUTION: The production method comprises (A) a step to perform the oxidative dimerization reaction of DAP with an oxygen-containing gas in the presence of an aqueous solvent and a metal catalyst and obtain an aqueous slurry containing TABP dispersed in an aqueous reaction liquid containing unreacted DAP, the metal catalyst and a carbonylphenol (CP) compound as an impurity and (B) a step to separate TABP from the aqueous slurry by solid-liquid separation process. The aqueous slurry and/or the aqueous reaction liquid recovered by the step B are distilled to recover an azeotropic mixture composed of water and the unreacted DAP and a part of the recovered fraction containing the CP compound is supplied to the oxidative dimerization reaction step. COPYRIGHT: (C)2005,JPO&NCIPI