| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a dihydroxydiphenyl sulfone isomer containing 2,4'-dihydroxydiphenyl sulfone in a larger amount by using an aqueous solvent from the dihydroxydiphenyl sulfone isomer mixture having a low 2,4'-dihydroxydiphenyl sulfone content. SOLUTION: The method for producing a dihydroxydiphenyl sulfone isomer mixture comprises adding an alkali to a crude isomer mixture containing 2,4'- dihydroxydiphenyl sulfone and 4,4'-dihydroxydiphenyl sulfone in an aqueous solvent and heat-treating the mixture and then cooling the solution and filtering the deposited crystal mainly composed of 4,4'-dihydroxydiphenyl sulfone and then adding an acid to the filtrate. COPYRIGHT: (C)2004,JPO
|
