Process for preparing bisimide products
US5290945A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1992 |
| Grant date | Mar 1, 1994 |
| Priority date | — |
| Expiry date | Aug 11, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D209/48
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention relates to a process for preparing a white bisimide product which principally contains N,N'-alkylene-bis(tetrabromophthalimide) or N,N'-bis(tetrabromophthalimide). The process features: providing, in a reaction vessel, a solution containing tetrabromophthalic anhydride and a solvent which contains at least about 15 weight percent of a mono-, di- or tri- carboxylic acid having a dissociation constant not higher than 1.0.times.10.sup.-3 at 25.degree. C.; forming a reaction mass by adding to the solution a diamine or a diamine salt formed by the partial or total diamine neutralization of a mono-, di- or tri- carboxylic acid having a dissociation constant not higher than 1.0.times.10.sup.-3 at 25.degree. C., such formation of the reaction mass resulting in the production of a bisimide precipitate which becomes a constituent of the reaction mass; during the formation of the reaction mass, (i) retaining, in the reaction mass, at least a portion of the water produced during such formation, (ii) maintaining a substantially constant pressure in the reaction vessel, and (iii) not allowing the temperature of the reaction mass to reach a temperature below about 135.degree. C.; t…
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