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US 5,210,321 AGranted
Diphenyl oxide bromination process
AssigneeEthyl Corporation
InventorsBonnie G. McKinnie, Mark A. Templeton
Life of this patent
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Abstract
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.
Claims12
A process for preparing a mixture of brominated diphenyl oxides having improved color characteristics, said process comprising:
- (a) forming a first reaction mass by adding molten diphenyl oxide to a reaction vessel containing bromine and a catalytic amount of zirconium catalyst, the amount of bromine providing a molar ratio of from about 7 to about 8.5 moles of bromine per mole of diphenyl oxide added;
- (b) maintaining the first reaction mass for a period of time and at a temperature which are sufficient to yield a mixture of brominated diphenyl oxides having an average bromine number of from about 5.8 to abut 6.5;
- and
- (c) subsequent to the substantial cessation of the bromination reaction in he first reaction mass, forming a second reaction mass by adding an iron catalyst to the first reaction mass, and if needed, additional amounts of bromine, to yield a mixture of brominated diphenyl oxides having improved color characteristics and processing an average bromine number of from about 7.0 to about 7.8.
1 more element
A process for preparing an Octabrom with improved color characteristics, said process comprising:
- (a) forming a first reaction mass by adding diphenyl oxide to reaction vessel previously charged with bromine and a catalytic amount of zirconium catalyst, the amount of bromine providing a molar ratio of from about 7 to about 8.5 moles of bromine per mole of diphenyl oxide added;
- (b) maintaining the first reaction mass for a period of time and at a temperature ranging from abut b 10.degree. C. to reflux, such that a mixture of brominated diphenyl oxides is formed, said mixture having an average of about 6.0 to about 6.5 arbromine atoms per molecule of diphenyl oxide added in (a);
- (c) subsequent to the substantial cessation of the bromination reaction in the first reaction mass, forming a second reaction mass by adding an iron powder catalyst to the first reaction mass, and if needed, additional amounts of bromine to yield Octabrom having improved color characteristics;
- and
- (d) recovering Octabrom having improved color characteristics from the second reaction mass.
2 more elements
Dependencies are inferred from the claim text.