US3318658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polypyrrolidone fibers and process
Assignee: 3M Co
•
Filing: 1962-12-21
•
Granted: 1967-05-09
•
Expires: 1982-12-21
Abstract
No abstract record available.
Inventors
- 👤 Sidney M Leahy
- 👤 Albert C Tanquary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:54
CPC Classifications
D; D06; D06M; D06M13/00; D06M13/10; D06M13/12; D06M13/127; D01; D01F; D01F6/00; D01F6/58; D01F6/60
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
35 words
THE PROCESS FOR BENEFICIATING POLYPYRROLIDONE FIBERS WHICH CONSISTS ESSENTIALLY IN SUBJECTING POLYPYRROLIDONE FIBERS TO THE ACTION OF FORMALDEHYDE IN THE PRESENCE OF AN ACIDIC METHYLOLATION CATALYST UNDER NON-SOLUBILIZING CONDITIONS, AND REMOVING WATER TO EFFECT CROSSLINKING.
Claim 2
Dependent Claim
35 words
THE PROCESS FOR BENEFICIATING POLYPYRROLIDONE FIBERS WHICH CONSISTS ESSENTIALLY IN SUBJECTING POLYPYRROLIDONE FIBERS TO THE ACTION OF FORMALDEHYDE IN THE PRESENCE OF AN ACIDIC METHYLOLATION CATALYST UNDER NON-SOLUBILIZING CONDITIONS, AND REMOVING WATER TO EFFECT CROSSLINKING.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-05-08 | 1970-11-07 | 1971-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-05-08 | 1974-11-07 | 1975-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-05-08 | 1978-11-07 | 1979-05-09 | $7700.00 | Window Closed / Lapsed |