| 摘要 |
PURPOSE:To efficiently obtain high-purity 2,4'-dihydroxy-diphenyl sulfones useful as a developer, etc., for thermographic paper. CONSTITUTION:Crude 2,4-dihydroxydiphenyl sulfones obtained by reaction of phenols with sulfuric acid are treated with (1) a mixed solvent of 5-20wt.% lower aliphatic alcohols and 95-80wt.% non-halogen-based aromatic hydrocarbons or (3) a mixed solvent of 10-40wt.% acetic acid esters and 90-60wt.% non-halogen based aromatic hydrocarbons to produce the objective high purity 2,4'- dihydroxydiphenyl sulfones. |
