Process for preparing anhydrous salts of dihydroxy aromatic compounds.

摘要

Anhydrous di-(alkali metal) (especially disodium) salts of dihydroxy aromatic compounds such as bisphenol A are preferred by first contacting the solid dihydroxy aromatic compound with an aqueous alkali metal hydroxide solution so as to convert it into its alkali metal salt or the hydrate thereof, typically in slurry; subsequently separating the solid salt or hydrate from the aqueous system and mixing the same with an organic liquid to create a system adapted for removal of water, including water of hydration, by evaporation; and evaporating said water. Typically, the organic liquid is one in which water and the anhydrous di-(alkali metal) salt are substantially insoluble; it is preferably toluene or o-dichlorobenzene.