Patent US4270189A successfully refreshed from Google Patents.
Patent US3702844A successfully refreshed from Google Patents.
US3702844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyvinyl alcohol-phosphoric acid films
Assignee: 3M Co
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Filing: 1970-08-17
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Granted: 1972-11-14
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Expires: 1990-08-17
Abstract
Abstract COATINGS AND SELF-SUPPORTING FILMS OF POLYVINYL ALCOHOL ARE PROVIDED, SAID FILMS AND COATINGS COMPRISING POLYVINYL ALCOHOL CONTAINING FROM 1 TO 20 PERCENT OF ORTHOPHOSPHORIC ACID, AND SAID FILM BEING COLORLESS, TRANSPARENT, SEMI-PERMEABLE, AND STRONG. THE FILMS AND COATINGS ARE DRIED AT OR NEAR ROOM TEMPERATURE AFTER BEING COATED.
Inventors
- 👤 Ronald F Ofstead
- 👤 Ramsis Gobran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:07
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/30; C; C09; C09D; C09D129/00; C09D129/02; C09D129/04; G03C1/04; G03C1/053; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/3188; Y10T428/31895
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) | 1975-11-14 | 1976-05-15 | 1976-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-14 | 1980-05-15 | 1980-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-14 | 1984-05-15 | 1984-11-14 | $7700.00 | Window Closed / Lapsed |