US3879428A
Expired / Lapsed
US
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Method for making aromatic bis(ether anhydride)s
Assignee: General Electric Co
•
Filing: 1973-03-30
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Granted: 1975-04-22
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Expires: 1993-03-30
Abstract
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.
Inventors
- 👤 Darrell R Heath
- 👤 Tohru Takekoshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:53
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
20 words
A METHOD FOR MAKING AN AROMATIC-BIS(ETHER ANHYDRIDE) WHICH COMPRISES A. EFFECTING THE NITRO DISPLACEMENT OF A NITROPHTHALIMIDE OF THE FORMULA,
Claim 2
Independent Claim
20 words
A METHOD FOR MAKING AN AROMATIC-BIS(ETHER ANHYDRIDE) WHICH COMPRISES A. EFFECTING THE NITRO DISPLACEMENT OF A NITROPHTHALIMIDE OF THE FORMULA,
Claim 3
Independent Claim
20 words
A method for making an aromatic-bis(ether anhydride) which comprises a. effecting the nitro displacement of a nitrophthalimide of the formula,
Claim 4
Independent Claim
20 words
A method for making an aromatic-bis(ether anhydride) which comprises a. effecting the nitro displacement of a nitrophthalimide of the formula,
Claim 5
Dependent Claim
16 words
A method in accordance with claim 1, where the alkali diphenoxide is the diphenoxide of bisphenol-A.
Claim 6
Dependent Claim
16 words
A method in accordance with claim 1, where the alkali diphenoxide is the diphenoxide of hydroquinone.
Claim 7
Dependent Claim
11 words
A method in accordance with claim 1, where R1 is phenyl.
Claim 8
Dependent Claim
11 words
A method in accordance with claim 1, where R1 is methyl.
Claim 9
Dependent Claim
11 words
A method in accordance with claim 1, where M is sodium.
Claim 10
Dependent Claim
11 words
A method in accordance with claim 1, where N-phenyl-3-nitrophthalimide is used.
Claim 11
Dependent Claim
11 words
A method in accordance with claim 1, where N-phenyl-4-nitrophthalimide is used.
Claim 12
Dependent Claim
16 words
A method in accordance with claim 1, where a mixture of N-phenyl-3-nitrophthalimide and N-phenyl-4-nitrophthalimide is used.
Claim 13
Dependent Claim
11 words
A method in accordance with claim 1, where N-methyl-3-nitrophthalimide is used.
Claim 14
Dependent Claim
11 words
A method in accordance with claim 1, where N-methyl-4-nitrophthalimide is used.
References Cited (Backward Citations)
US3787475A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |