| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of preparing a bisphenol A having a satisfactory quality usable for manufacturing a high quality polycarbonate resin, from a bisphenol A inferior in quality which is precipitated by acid deposition from a reaction waste water, in the manufacture of a polycarbonate resin. SOLUTION: The recycling method for bisphenol A is characterised by processes such that (1) an acid is added to an alkali water solution containing bisphenol A discharged from a polycarbonate manufacturing process to precipitate solids, and the solids are filtered, (2) the resultant solids containing bisphenol A are mixed with phenol and water, heated at a temperature of 70-150°C to be dissolved, then cooled to a temperature of 15-60°C, to precipitate a solid matter (bisphenol A-phenol adduct), and then the solid matter is filtered, and (3) the resultant high quality bisphenol A-phenol adduct is used as a raw material of polycarbonate resin. COPYRIGHT: (C)2008,JPO&INPIT
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