Diphenyl oxide bromination process

摘要

A process for producing a mixture of brominated diphenyl oxides with an average bromine number of 7.0 to 7.8 is improved by the utilization of a multi-step, multi-catalyst procedure. The process uses a zirconium catalyst in the first reaction and an iron catalyst in the second reaction to yield a whiter flame retardant product having less tendency to discolor plastic resins.