US3679646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of polyvinyl alcohol having improved color properties by treating the polyvinyl ester with an alkali metal borohydride
Assignee: EIDP Inc
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Filing: 1970-08-05
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Granted: 1972-07-25
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Expires: 1990-08-05
Abstract
Abstract POLYVINYL ALCOHOL HAVING IMPROVED COLOR PROPERTIES IS PREPARED IN ROCESS IN WHICH AN ALCOHOLIC SOLUTION OF THE POLYVINYL ESTER UTILIZED TO PREPARE THE POLYVINYL ALCOHOL IS TREATED WITH AN ALKALI METAL BOROHYDRIDE PRIOR TO THE ALCOHOLYSIS OF THE POLYVINYL ESTER TO THE CORRESPONDING POLYVINYL ALCOHOL.
Inventors
- 👤 John E Bristol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:13
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |