US3520774A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Epichlorodydrin-polyethyleneimine wet strength additive for paper
Assignee: Dow Chemical Co
•
Filing: 1967-09-28
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Granted: 1970-07-14
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Expires: 1987-09-28
Abstract
No abstract record available.
Inventors
- 👤 Harold H Roth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:15
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/46; D21H17/54; C; C08; C08G; C08G73/00; C08G73/02; C08G73/0206; C08G73/0213; C08G73/022
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2182306A
Cited
US2272489A
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US2296225A
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US2595935A
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US2601597A
Cited
US2849411A
Cited
US2969302A
Cited
GB1020811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-13 | 1974-01-12 | 1974-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-13 | 1978-01-12 | 1978-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-13 | 1982-01-12 | 1982-07-14 | $7700.00 | Window Closed / Lapsed |