PRODUCTION OF LIQUID BROMINATED DIPHENYL ETHER

摘要

PURPOSE:To obtain the titled compound having low crystal precipitation degree and high compatibility and storage stability and useful as a flame-retardant, by reacting diphenyl ether with bromine in a hydrogen halide atmosphere in the presence of a catalyst and in the absence of solvent under specific reaction condition. CONSTITUTION:Diphenyl ether and bromine are used as raw materials for the present process. 1mol of diphenyl ether is made to react with 4.0-4.6mol of bromine in hydrogen halide atmosphere in the presence of a Lewis acid catalyst or iron powder catalyst at 35-55 deg.C, preferably 40-50 deg.C in the absence of solvent to obtain a liquid brominated diphenyl ether having a bromine content of 60-66wt% (especially a compound containing 62.0-65.5% bromine is effective) and a refractive index (25 deg.C) of 1.6680-1.6880 and causing no crystal precipitation at -20 deg.C. The compound is compounded to a thermosetting resin to impart the resin with flame-retardance. The amount of the compound to be blended is preferably 2-30pts. per 100pts. of the thermosetting resin.