Process for high purity tetrabromobisphenol-A
US5283375A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1992 |
| Grant date | Feb 1, 1994 |
| Priority date | — |
| Expiry date | Dec 15, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C39/367
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention relates to a process for preparing a flame retardant product predominant in tetrabromobisphenol-A. The process comprises: (a) dissolving bisphenol-A in a methanol solvent containing up to about 5 weight percent water, wherein the ratio of methanol to bisphenol-A ranges from about 25 to about 43 moles of methanol per mole of bisphenol-A based on the total amount of methanol used and the total amount of bisphenol-A to be brominated; (b) adding to the solution in (a) from about 3.9 to about 4.2 moles of bromine per mole of bisphenol-A to be brominated while maintaining a reaction temperature in the range of from about 0.degree. to about 40.degree. C.; (c) after the bromination is substantially complete, adding water to precipitate the tetrabromobisphenol-A thus formed; and (d) purifying the precipitated tetrabromobisphenol-A so as to obtain a product predominant in tetrabromobisphenol-A containing less than about 20 ppm total ionic impurity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.