| 摘要 |
A process of preparing 4,4'-Bisphenol S wherein sulfuric acid is reacted with an excess of phenol while removing water; the product purity is improved with respect to the 2,4'-BPS isomer by adding toluene to the initial product mixture to crystallize and remove the desired 4,4'-BPS. The remaining material is recycled to isomerize the 2,4'-BPS to 4,4'-BPS. |
