PURPOSE: To obtain the title compound with little discoloration useful as flame retardants or their raw material for synthetic resins or fibers, by depositing and purifying the title compound from a solution of a halogenated bisphenol in an aqueous alkali hydroxide with an acid.
CONSTITUTION: A halogenated bisphenol, e.g. tetrabromobisphenol A, of the formula (A is ≤5C alkylene group, ect.; X and Y are Cl or Br; m and n are integers 1W3) is dessolved in an aqueous solution of analkali hydroxide, e.g. NaOH or KOH, and an acid, e.g. HCl, is added to the solution to deposit and purify the bisphenol. White powder of the objective compound is thus obtained. Preferably, the deposition is carried out in an aqueous solution system comprising a water- immiscible organic solvent having a specific gravity ≥ 1.
EFFECT: Simple treatment to deposit the objictive compound is sufficient without requiring any special procedure with a decolorant or adsorbent.
GOTOU ISAO
IKEMURA MASAAKI
| JPS49110653A | 1974-10-22 |