Verfahren zur kontinuierlichen Herstellung von Dihydroxydiarylalkanen

摘要

The present invention relates to method for continuous production of dihydroxydiarylalkanes (bisphenols) by reacting fresh phenol and isolalkenylphenol from the cleavage of by-products and ketone. The main amount of bisphenol is obtained from the reaction mixture by means of crystallization. The mother liquor thus obtained is released from the phenol by means of distillation. The phenol is re-reacted . The residue obtained during distillation is cleaved by adding a basic catalyst in a reactive rectification. The overhead phenol and isoalkenylphenol is re-reacted. The residue from the first reaction column is acidified and is further cleaved in a second reactive rectification in the presence of an acidic catalyst and turned into distilled phenol which is used again in the reaction and the residue is removed.