Patent US3989712A successfully refreshed from Google Patents.
US3989712A
Expired / Lapsed
US
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Thio-bis(phthalimides)
Assignee: General Electric Co
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Filing: 1973-03-30
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Granted: 1976-11-02
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Expires: 1993-03-30
Abstract
Abstract A method is provided for making bis(thioetherphthalic anhydride)s from bis(thioetherphthalimide)s. The latter compounds can be made by using an alkali metal sulfide with an N-substituted phthalimide having an alkali metal sulfide displaceable radical attached to the ring.
Inventors
- 👤 Frank J. Williams, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:51
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/77; C07D307/87; C07D307/89; C07D209/00; C07D209/02; C07D209/04; C07D209/30; C07D209/32; C07D209/38; C08; C08G; C08G59/00; C08G59/18; C08G59/40; C08G59/42; C08G59/423
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
1 words
3,3'-bis(N-phenylphthalimide)sulfide.
Claim 2
Dependent Claim
1 words
3,3'-bis(N-phenylphthalimide)sulfide.
Claim 3
Dependent Claim
1 words
4,4'-bis(N-phenylphthalimide)sulfide.
Claim 4
Dependent Claim
1 words
4,4'-bis(N-phenylphthalimide)sulfide.
Claim 5
Dependent Claim
1 words
3,3'bis(N-butylphthalimide)sulfide.
Claim 6
Dependent Claim
1 words
3,3'bis(N-butylphthalimide)sulfide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-02 | 1980-05-03 | 1980-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-02 | 1984-05-03 | 1984-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-02 | 1988-05-03 | 1988-11-02 | $7700.00 | Window Closed / Lapsed |