Method of making aromatic bis(ether ortho phthalic acid)s
US3957862A · kind A · utility
34Cited by
1References
9Claims
0Family size
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Key dates
| Filing date | Dec 6, 1974 |
| Grant date | May 18, 1976 |
| Priority date | — |
| Expiry date | Dec 6, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C65/24
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Aromatic bis(ether anhydride)s can be made by a nitro displacement of an N-substituted nitrophthalimide with an alkali diphenoxide to produce an intermediate aromatic bis(etherphthalimide). Hydrolysis of the aromatic bis(etherphthalimide) to the corresponding tetra-acid salt followed by acidification and dehydration, results in the production of the aromatic bis(ether anhydride). These anhydrides can be used as intermediates for making polyimides. The intermediate aromatic bis(etherphthalimide) can be employed as a plasticizer in polyimide resins.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.