Patent US2649357A successfully refreshed from Google Patents.
US2649357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of artificial protein threads, fibers, filaments, and the like
Assignee: Akzo Nobel UK PLC
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Filing: 1951-09-18
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Granted: 1953-08-18
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Expires: 1971-09-18
Abstract
No abstract record available.
Inventors
- 👤 Happey Frank
- 👤 Robert L Wormell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:58
CPC Classifications
D; D01; D01F; D01F4/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
50 words
A PROCESS FOR THE OXIDATIVE PRETREATMENT OF KERATIN PREPARATORY TO ITS SOLUTION IN AN AQUEOUS ALKALINE SOLVENT, WHICH COMPRISES SUBJECTING THE KERATIN TO THE ACTION OF HYDROGEN PEROXIDE IN THE PRESENCE OF FERROUS SULPHATE AND AN ACID CHOSEN FROM THE GROUP CONSISTING OF SULPHURIC ACID, PHOSPHORIC ACID AND ACETIC ACID.
Claim 2
Dependent Claim
50 words
A PROCESS FOR THE OXIDATIVE PRETREATMENT OF KERATIN PREPARATORY TO ITS SOLUTION IN AN AQUEOUS ALKALINE SOLVENT, WHICH COMPRISES SUBJECTING THE KERATIN TO THE ACTION OF HYDROGEN PEROXIDE IN THE PRESENCE OF FERROUS SULPHATE AND AN ACID CHOSEN FROM THE GROUP CONSISTING OF SULPHURIC ACID, PHOSPHORIC ACID AND ACETIC ACID.
References Cited (Backward Citations)
US2131145A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-08-17 | 1957-02-16 | 1957-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-08-17 | 1961-02-16 | 1961-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-08-17 | 1965-02-16 | 1965-08-18 | $7700.00 | Window Closed / Lapsed |