Patent US2915504A successfully refreshed from Google Patents.
US2915504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyvinyl butyral
Assignee: Celanese Corp
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Filing: 1954-09-23
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Granted: 1959-12-01
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Expires: 1974-09-23
Abstract
No abstract record available.
Inventors
- 👤 Berardinelli Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:37
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
114 words
PROCESS FOR THE PRODUCTION OF POLYVINYL BUTYRAL WHICH COMPRISES HEATING A SLURRY OF SOLID POLYVINYL ACETATE IN A NON-SOLVENT THEREFOR COMPRISING WATER AND METHANOL IN THE PRESENCE OF A STRONG ACID CATALYST TO PRODUCER METHYL ACETATE BY THE DEESTERIFICATION OF SAID POLYVINYL ACETATE DISTILLING OFF SAID METHYL ACETATE FROM THE RESULTING SOLUTION, ADDING WATER TO SAID SOLUTION DURING THE DISTILLATION TO REPLACE THE DISTILLED MATERIAL, COOLING SAID SOLUTION TO A TEMPERATURE NOT ABOVE ABOUT 50* C. BY ADDING WATER AT A LOWER TEMPERATURE THERETO, ADDING BUTYRALDEHYDE TO SAID COOLED SOLUTION TO CAUSE THE PRECIPITATION THEREFROM OF A POLYVINYL BUTYRAL IN THE FORM OF FINE PARTICLES, AND SEPARATING THE POLYVINYL BUTYRAL PARTICLES FROM SAID SOLUTION.
Claim 2
Dependent Claim
114 words
PROCESS FOR THE PRODUCTION OF POLYVINYL BUTYRAL WHICH COMPRISES HEATING A SLURRY OF SOLID POLYVINYL ACETATE IN A NON-SOLVENT THEREFOR COMPRISING WATER AND METHANOL IN THE PRESENCE OF A STRONG ACID CATALYST TO PRODUCER METHYL ACETATE BY THE DEESTERIFICATION OF SAID POLYVINYL ACETATE DISTILLING OFF SAID METHYL ACETATE FROM THE RESULTING SOLUTION, ADDING WATER TO SAID SOLUTION DURING THE DISTILLATION TO REPLACE THE DISTILLED MATERIAL, COOLING SAID SOLUTION TO A TEMPERATURE NOT ABOVE ABOUT 50* C. BY ADDING WATER AT A LOWER TEMPERATURE THERETO, ADDING BUTYRALDEHYDE TO SAID COOLED SOLUTION TO CAUSE THE PRECIPITATION THEREFROM OF A POLYVINYL BUTYRAL IN THE FORM OF FINE PARTICLES, AND SEPARATING THE POLYVINYL BUTYRAL PARTICLES FROM SAID SOLUTION.
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) | 1962-11-30 | 1963-06-01 | 1963-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-30 | 1967-06-01 | 1967-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-30 | 1971-06-01 | 1971-12-01 | $7700.00 | Window Closed / Lapsed |