Process for producing tetrabromobisphenol-A

A process for the preparation of tetrabromobisphenol-A, which process comprises:

• a) feeding to a reactor at least bisphenol-A, underbrominated bisphenol-A, a water-miscible solvent, bromine, water, and an oxidant to at least partially form a reaction mass having a liquid phase in which tetrabromobisphenol-A is relatively insoluble;
• b) substantially throughout the feed in a), providing for the presence of a stoichiometric deficiency of bromine relative to the bisphenol-A and underbrominated bisphenol-A to thereby form in the reaction mass, a precipitate consisting essentially of about 50 to about 95 wt % of tetrabromobisphenol-A and about 50 to about 5 wt % of underbrominated bisphenol-A;
• c) removing precipitate and optionally a portion of the reaction mass from the reactor;
• and
• d) separating tetrabromobisphenol-A and underbrominated bisphenol-A from each other.

A process for the preparation of tetrabromobisphenol-A, which process comprises:

• a) feeding, to a reactor, a solution comprised of bisphenol-A, water and a water-miscible solvent to at least partially form a reaction mass having a liquid phase containing an amount of water in the range of from above about 15 to about 65 wt % water that renders tetrabromobisphenol-A substantially insoluble in said liquid phase, the wt % being based upon the amount of water and water-miscible solvent in the liquid phase;
• b) during a), providing for the presence of Br.sub.2 in the reaction mass to produce tetrabromobisphenol-A and HBr co-product;
• c) oxidizing HBr produced in the reaction mass to yield Br.sub.2 ;
• d) having a reaction mass temperature which is within the range of from about 50 to about 100.degree. C.;
• e) keeping the total amount of bromine provided in a) and produced in c) sufficiently below the stoichiometric amount required to convert all of the bisphenol-A present in the reactor to tetrabromobisphenol-A so that a precipitate is formed composed of about 50 to about 95 wt % of tetrabromobisphenol-A and about 50 to about 5 wt % of underbrominated bisphenol-A.

A process for the preparation of tetrabromobisphenol-A, which process comprises:

• a) feeding to a reactor at least bisphenol-A, underbrominated bisphenol-A, a water-miscible solvent, bromine, and water to at least partially form a reaction mass having a liquid phase in which tetrabromobisphenol-A is relatively insoluble;
• b) substantially throughout the feed in a), providing for the presence of a stoichiometric deficiency of bromine relative to the bisphenol-A and underbrominated bisphenol-A to thereby form in the reaction mass, a precipitate consisting essentially of about 50 to about 95 wt % of tetrabromobisphenol-A and about 50 to about 5 wt % of underbrominated bisphenol-A;
• c) removing from the reactor at least a portion of the reaction mass including precipitate;
• d) separating tetrabromobisphenol-A and underbrominated bisphenol-A from each other;
• and
• e) recycling underbrominated bisphenol-A as feed in a).