PRODUCTION OF HIGH-QUALITY TETRABROMOBISPHENOL A

PURPOSE:To obtain high-quality tetrabromobisphenol A, directly usable as a flame retardant for resins in applications of electrical and electronic materials such as laminated boards and sealing madia without requiring special purification steps, reduced in hydrolyzable bromine content and improved in hue. CONSTITUTION:Bisphenol A(BPA) is brominated with bromine in an alcohol (preferably methanol) to produce tetrabromobisphenol A(TBA) useful as a flame retardant for epoxy resins, ABS resins, etc. In the process, the reaction temperature is regulated to -10 to +20 deg.C, preferubly 0 to +15 deg.C and water in an amount of normally 2-15wt.%, preferably 3-10wt.% based on the reaction solvent is added in an aging step. Thereby, the objective high-quality TBA with the hydrolytic bromine content reduced to 2-50ppm and improved hue is obtained. Furthermore, the aging time can remarkably be shortened by the aforementioned method as compared with that of conventional methods in which an alcohol is solely used as the reaction solvent. In addition, reaction of hydrogen bromide formed by the brominating reaction with the alcohol which is the solvent can also be suppressed.