Patent US2558675A successfully refreshed from Google Patents.
US2558675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
N-acyl polyimides of polycarboxylic acids
Assignee: Wingfoot Corp
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Filing: 1950-04-29
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Granted: 1951-06-26
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Expires: 1970-04-29
Abstract
No abstract record available.
Inventors
- 👤 Paul J Flory
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:49
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
32 words
AS A NEW COMPOUND, AN N-ACYL POLYIMIDE OF A POLYCARBOXYLIC ACID IN WHICH EACH OF THE CARBONYL GROUPS OF THE ACYL RADICAL IS ATTACHED TO THE NITROGEN ATOM OF AN IMIDO RADICAL.
Claim 2
Dependent Claim
32 words
AS A NEW COMPOUND, AN N-ACYL POLYIMIDE OF A POLYCARBOXYLIC ACID IN WHICH EACH OF THE CARBONYL GROUPS OF THE ACYL RADICAL IS ATTACHED TO THE NITROGEN ATOM OF AN IMIDO RADICAL.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-06-25 | 1954-12-25 | 1955-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-25 | 1958-12-25 | 1959-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-25 | 1962-12-25 | 1963-06-26 | $7700.00 | Window Closed / Lapsed |