US3472840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quaternary nitrogen-containing cellulose ethers
Assignee: Union Carbide Corp
•
Filing: 1965-09-14
•
Granted: 1969-10-14
•
Expires: 1985-09-14
Abstract
No abstract record available.
Inventors
- 👤 Fred W Stone
- 👤 John M Rutherford Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:00
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C02F1/5263; C08; C08B; C08B11/00; C08B11/02; C08B11/04; C08B11/14; C08B11/145; C08B11/193
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
GB486527A
Cited
US2768162A
Cited
US2931753A
Cited
US2876217A
Cited
US3087852A
Cited
US3388118A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-13 | 1973-04-14 | 1973-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-13 | 1977-04-14 | 1977-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-13 | 1981-04-14 | 1981-10-14 | $7700.00 | Window Closed / Lapsed |