US3556933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Regeneration of aged-deteriorated wet strength resins
Assignee: Wyeth Holdings LLC
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Filing: 1969-04-02
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Granted: 1971-01-19
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Expires: 1989-04-02
Abstract
Abstract WET STRENGTHENING EFFICIENCY OF AGED, DETERIORATED AQUEOUS SOLUTIONS OF WATER-SOLUBLE SULFITE-STABILIZED THERMOSETTING NORMALLY CATIONIC GLYOXALATED POLYVINYLAMIDE WET STRENGTH RESINS IS REJUVENATED BY ADDITION OF FORMALDEHYDE TO SAID SOLUTIONS.
Inventors
- 👤 Laurence Lyman Williams
- 👤 Anthony Thomas Coscia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:19
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/38; D21H17/39; C; C08; C08F; C08F8/00; C08F8/28; C08J; C08J5/00; C08J5/18; C08F2810/00; C08F2810/20
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) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |