US3549504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the purification of organic polyisocyanates by fractional distillation in presence of an inert gas or superheated vapor of an organic solvent
Assignee: Takeda Pharmaceutical Co Ltd
•
Filing: 1967-05-05
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Granted: 1970-12-22
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Expires: 1987-05-05
Abstract
No abstract record available.
Inventors
- 👤 Osamu Adica
- 👤 Kenji Naito
- 👤 Katsuhiko Ogino
- 👤 Hiroyuki Kuroda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:34
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/18; C07C263/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3210395A
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US3211631A
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US2731081A
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US2884359A
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US3179680A
Cited
US3317606A
Cited
US3410888A
Cited
US3405040A
Cited
US3440270A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-12-21 | 1974-06-22 | 1974-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-12-21 | 1978-06-22 | 1978-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-12-21 | 1982-06-22 | 1982-12-22 | $7700.00 | Window Closed / Lapsed |