Claims
- 1. 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.
- 2. The process of claim 1 being conducted in the substantial absence of a solvent other than liquid bromine.
- 3. The process of claim 1 wherein the temperature of the first reaction mass during (a) and (b) is from about 10.degree. C. up to reflux.
- 4. The process of claim 1 wherein the diphenyl oxide is added to the reaction vessel over a period of about 30 minutes to about 20 hours.
- 5. The process of claim 1 wherein the zirconium catalyst is a zirconium halide catalyst.
- 6. The process of claim 5 wherein the zirconium halide catalyst is charged to the reaction vessel as zirconium chloride.
- 7. The process of claim 1 wherein the iron catalyst is an iron powder catalyst.
- 8. The process of claim 1 wherein the temperature in step (c) is maintained in a range of from about 100.degree. C. to about 130.degree. C.
- 9. 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.
- 10. The process of claim 9 conducted in the substantial absence of a solvent other than liquid bromine.
- 11. The process of claim 10 wherein the diphenyl oxide is added to the reaction vessel over a period of about 30 minutes to about 10 hours.
- 12. The process of claim 9 wherein the temperature in step (c) is maintained in a range of about 70.degree. C. to about 150.degree. C.
Parent Case Info
This is a continuation-in-part of U.S. patent application Ser. No. 07/506,334 filed Apr. 9, 1990, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3763248 |
Mitchell |
Oct 1973 |
|
4717776 |
Brackenridge et al. |
Jan 1988 |
|
4740629 |
Brackenridge et al. |
Apr 1988 |
|
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
506334 |
Apr 1990 |
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