Patent ID: 6554967
Filing Date: 2003-04-29
Classification: C07C

Abstract:
A method of refining a dihydroxyaryl compound, comprising:evaporating a dihydroxyaryl compound in a distillation column, wherein a top outlet of the distillation column is connected to a condenser; suspending said evaporation step and applying a hot water or steam treatment to the inside surface of the condenser; condensing the resultant vapor fraction of the dihydroxyaryl compound in said condenser so that the condensed dihydroxyaryl compound comes into contact with said inside surface of the condenser; and collecting the condensed dihydroxyaryl compound fraction into a storage tank through a conduit connected to an outlet of the condenser; wherein the condenser has an inside surface thereof formed from a metal material comprising at least 25% by weight nickel.