US3957862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making aromatic bis(ether ortho phthalic acid)s
Assignee: General Electric Co
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Filing: 1974-12-06
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Granted: 1976-05-18
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Expires: 1994-12-06
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
2026-11-01 00:28
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48; C07C; C07C65/00; C07C65/21; C07C65/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
104 words
A method for making an aromatic-bis(ether dicarboxylic acid) which comprises a. effecting the nitro displacement of a nitrophthalimide of the formula, ##SPC9## with an alkali diphenoxide of the formula, M--O--R--O--M to produce an intermediate aromatic-bis(etherphthalimide), (b) hydrolizing the aromatic-bis(etherphthalimide) of (a) with base to produce a tetra-carboxylic-acid-salt and (c) acidifying the tetra-carboxylic-acid salt to produce the corresponding tetra-carboxylic-acid, where R is a divalent aromatic radical having from 6-30 carbon atoms, M is an alkali metal ion, and R 1 is a monovalent organo radical selected from the class consisting of aromatic hydrocarbon radicals, halogenated aromatic hydrocarbon radicals and altyl radicals of 1--8 carbon atoms.
Claim 2
Independent Claim
104 words
A method for making an aromatic-bis(ether dicarboxylic acid) which comprises a. effecting the nitro displacement of a nitrophthalimide of the formula, ##SPC9## with an alkali diphenoxide of the formula, M--O--R--O--M to produce an intermediate aromatic-bis(etherphthalimide), (b) hydrolizing the aromatic-bis(etherphthalimide) of (a) with base to produce a tetra-carboxylic-acid-salt and (c) acidifying the tetra-carboxylic-acid salt to produce the corresponding tetra-carboxylic-acid, where R is a divalent aromatic radical having from 6-30 carbon atoms, M is an alkali metal ion, and R 1 is a monovalent organo radical selected from the class consisting of aromatic hydrocarbon radicals, halogenated aromatic hydrocarbon radicals and altyl radicals of 1--8 carbon atoms.
Claim 3
Dependent Claim
16 words
A method in accordance with claim 1 where the alkali diphenoxide is the diphenoxide of bisphenol-A.
Claim 4
Dependent Claim
16 words
A method in accordance with claim 1 where the alkali diphenoxide is the diphenoxide of hydroquinone.
Claim 5
Dependent Claim
12 words
A method in accordance with claim 1 where R 1 is phenyl.
Claim 6
Dependent Claim
12 words
A method in accordance with claim 1 where R 1 is methyl.
Claim 7
Dependent Claim
11 words
A method in accordance with claim 1 where M is sodium.
Claim 8
Dependent Claim
11 words
A method in accordance with claim 1 where N-phenyl-3-nitrophthalimide is used.
Claim 9
Dependent Claim
11 words
A method in accordance with claim 1 where N-phenyl-4-nitrophthalimide is used.
Claim 10
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.
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) | 1979-05-18 | 1979-11-17 | 1980-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-18 | 1983-11-17 | 1984-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-18 | 1987-11-17 | 1988-05-18 | $7700.00 | Window Closed / Lapsed |