Patent US3493575A successfully refreshed from Google Patents.
US3493575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
1,4-chlorosubstituted-2,3,5,6-piperazinetetraones
Assignee: Dow Chemical Co
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Filing: 1967-05-16
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Granted: 1970-02-03
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Expires: 1987-05-16
Abstract
No abstract record available.
Inventors
- 👤 Donald A Tomalia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:58
CPC Classifications
C; C07; C07D; C07D241/00; C07D241/02; C07D263/00; C07D263/02; C07D263/08; C07D263/10; C07D263/12; C07D265/00; C07D265/04; C07D265/06; C07D265/08
Claims Analysis
Total Claims: 0
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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) | 1973-02-02 | 1973-08-04 | 1974-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-02 | 1977-08-04 | 1978-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-02 | 1981-08-04 | 1982-02-03 | $7700.00 | Window Closed / Lapsed |