Patent ID: 8530705

Claim:
A purification method of dihydroxybenzene comprising the following steps, for obtaining purified dihydroxybenzene from crude dihydroxybenzene containing at least isopropenylphenol and hydroxyacetophenone as impurities: first extraction step: water is added to crude dihydroxybenzene to prepare a dihydroxybenzene aqueous solution A, then, the solution is subjected to extraction by allowing it to contact with an extraction solvent ( 1 ), to be separated into a first fraction containing dihydroxybenzene, hydroxyacetophenone and water and a second fraction containing isopropenylphenol and the extraction solvent ( 1 ), distillation step: the first fraction obtained in the first extraction step is subjected to distillation, to be separated into a third fraction containing water and a fourth fraction containing dihydroxybenzene and hydroxyacetophenone, then, the fourth fraction is subjected to distillation, to be separated into a fifth fraction as purified dihydroxybenzene and a sixth fraction as dihydroxybenzene containing concentrated hydroxyacetophenone, second extraction step: water is added to the sixth fraction obtained in the distillation step to prepare a dihydroxybenzene aqueous solution B, then, the solution is subjected to extraction by allowing it to contact with an extraction solvent ( 2 ), to be separated into a seventh fraction containing dihydroxybenzene, hydroxyacetophenone, and water and an eighth fraction containing hydroxyacetophenone and the extraction solvent ( 2 ), recovery step: dihydroxybenzene is recovered from the seventh fraction obtained in the second extraction step or the seventh fraction obtained in the second extraction step is fed to the entrance of the first extraction step.