Patent US2642420A successfully refreshed from Google Patents.
US2642420A
Expired / Lapsed
US
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Preparation of polyvinyl alcohol
Assignee: Eastman Kodak Co
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Filing: 1948-07-02
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Granted: 1953-06-16
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Expires: 1968-07-02
Abstract
No abstract record available.
Inventors
- 👤 William O Kenyon
- 👤 George P Waugh
- 👤 Erle W Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:29
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
79 words
THE METHOD OF PREPARING A HIGHLY PURE POLYVINYL ALCOHOL WHICH COMPRISES DEACETYLATING POLYVINYL ACETATE WHILE IN A METHANOL SOLUTION BY THE AID OF AN ACID DEACETYLATING CATALYST TO FORM A POLYVINYL ALCOHOL GEL, CONTINUING THE DEACETYLATION TO PRODUCE A GEL WHICH IS INSOLUBLE IN WATER HAVING A TEMPERATURE NOT GREATER THAN APPROXIMATELY 50* C., AND WASHING THE GEL WITH WATER HAVING A TEMPERATURE NOT GREATER THAN APPROXIMATELY 50* C. UNTIL SUBSTANTIALLY FREE FROM THE REACTION BY-PRODUCTS AND RESIDUAL CATALYST.
Claim 2
Independent Claim
79 words
THE METHOD OF PREPARING A HIGHLY PURE POLYVINYL ALCOHOL WHICH COMPRISES DEACETYLATING POLYVINYL ACETATE WHILE IN A METHANOL SOLUTION BY THE AID OF AN ACID DEACETYLATING CATALYST TO FORM A POLYVINYL ALCOHOL GEL, CONTINUING THE DEACETYLATION TO PRODUCE A GEL WHICH IS INSOLUBLE IN WATER HAVING A TEMPERATURE NOT GREATER THAN APPROXIMATELY 50* C., AND WASHING THE GEL WITH WATER HAVING A TEMPERATURE NOT GREATER THAN APPROXIMATELY 50* C. UNTIL SUBSTANTIALLY FREE FROM THE REACTION BY-PRODUCTS AND RESIDUAL CATALYST.
References Cited (Backward Citations)
DE431146C
Cited
US2109833A
Cited
US2399653A
Cited
US2467774A
Cited
US2499097A
Cited
US2485141A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-15 | 1956-12-15 | 1957-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-15 | 1960-12-15 | 1961-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-15 | 1964-12-15 | 1965-06-16 | $7700.00 | Window Closed / Lapsed |