Patent US3220992A successfully refreshed from Google Patents.
US3220992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating polyvinyl alcohol
Assignee: Cumberland Chemical Corp
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Filing: 1962-06-11
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Granted: 1965-11-30
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Expires: 1982-06-11
Abstract
No abstract record available.
Inventors
- 👤 Smyser Harold Diemer
- 👤 Ora L Wheeler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:45
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
A METHOD OF TREATING POLYVINYL ALCOHOL HAVING A MOISTURE CONTENT BELOW ABOUT 10% AND A DEGREE OF HYDROLYSIS OF AT LEAST ABOUT 97.5%, AND SUBSTANTIALLY FREE FROM ORGANIC SOLVENTS AND ADAPTED TO BE SLURRIED IN WATER, WHICH COMPRISES SUBJECTING SAID POLYVINYL ALCOHOL TO STEAM WHILE CONTINUALLY AGITATING SAID POLYVINYL ALCOHOL TO INCREASE THE MOSITURE CONTENT OF SAID POLYVINYL ALCOHOL BY AT LEAST 1%, AND WHEREIN SAID POLYVINYL ALCOHOL WHILE BEING SUBJECTED TO STEAM IS MAINTAINED AT A TEMPERATURE OF ABOUT 40*C. TO ABOUT 150*C. SUFFICIENT TO IMPROVE THE COLD-WATER SLURRYING CHARACTERISTICS OF SAID POLYVINYL ALCOHOL, SAID STEAM BEING INTRODUCED AT A RATE TO MAINTAIN A SUBSTANTIALLY COMPLETE STEAM ATMOSPHERE IN THE TREATING AREA, AND DRYING THE THUS-TREATED POLYVINYL ALCOHOL TO A FINAL MOSITURE CONTENT OF NO MORE THAN ABOUT 4%.
Claim 2
Independent Claim
130 words
A METHOD OF TREATING POLYVINYL ALCOHOL HAVING A MOISTURE CONTENT BELOW ABOUT 10% AND A DEGREE OF HYDROLYSIS OF AT LEAST ABOUT 97.5%, AND SUBSTANTIALLY FREE FROM ORGANIC SOLVENTS AND ADAPTED TO BE SLURRIED IN WATER, WHICH COMPRISES SUBJECTING SAID POLYVINYL ALCOHOL TO STEAM WHILE CONTINUALLY AGITATING SAID POLYVINYL ALCOHOL TO INCREASE THE MOSITURE CONTENT OF SAID POLYVINYL ALCOHOL BY AT LEAST 1%, AND WHEREIN SAID POLYVINYL ALCOHOL WHILE BEING SUBJECTED TO STEAM IS MAINTAINED AT A TEMPERATURE OF ABOUT 40*C. TO ABOUT 150*C. SUFFICIENT TO IMPROVE THE COLD-WATER SLURRYING CHARACTERISTICS OF SAID POLYVINYL ALCOHOL, SAID STEAM BEING INTRODUCED AT A RATE TO MAINTAIN A SUBSTANTIALLY COMPLETE STEAM ATMOSPHERE IN THE TREATING AREA, AND DRYING THE THUS-TREATED POLYVINYL ALCOHOL TO A FINAL MOSITURE CONTENT OF NO MORE THAN ABOUT 4%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-29 | 1969-05-31 | 1969-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-29 | 1973-05-31 | 1973-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-29 | 1977-05-31 | 1977-11-30 | $7700.00 | Window Closed / Lapsed |