Patent US2862908A successfully refreshed from Google Patents.
US2862908A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyvinyl acetals
Assignee: Celanese Corp
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Filing: 1954-12-15
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Granted: 1958-12-02
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Expires: 1974-12-15
Abstract
No abstract record available.
Inventors
- 👤 Jones Wilford Donald
- 👤 Henry P Marshall
- 👤 Richard E Davies
- 👤 Walter D Paist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:05
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
53 words
IN THE PROCESS FOR THE PRODUCTION OF POLYVINYL FORMAL WHICH COMPRISES REACTING POLYVINYL ACETATE AND FORMALDEHYDE IN SOLUTION IN AQUEOUS ACETIC ACID CONTAINING AN ACID CATALYST FOR SAID REACTION, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE REACTION IN THE PRESENCE OF 0.5 TO 4%, BASED ON THE POLYVINYL ACETATE, OF SODIUM SULFOXYLATE FORMALDEHYDE.
Claim 2
Dependent Claim
53 words
IN THE PROCESS FOR THE PRODUCTION OF POLYVINYL FORMAL WHICH COMPRISES REACTING POLYVINYL ACETATE AND FORMALDEHYDE IN SOLUTION IN AQUEOUS ACETIC ACID CONTAINING AN ACID CATALYST FOR SAID REACTION, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE REACTION IN THE PRESENCE OF 0.5 TO 4%, BASED ON THE POLYVINYL ACETATE, OF SODIUM SULFOXYLATE FORMALDEHYDE.
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) | 1961-12-01 | 1962-06-02 | 1962-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-01 | 1966-06-02 | 1966-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-01 | 1970-06-02 | 1970-12-02 | $7700.00 | Window Closed / Lapsed |