US3282893A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing synthetic resins
Assignee: Union Carbide Corp
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Filing: 1961-07-03
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Granted: 1966-11-01
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Expires: 1981-07-03
Abstract
No abstract record available.
Inventors
- 👤 Shechter Leon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:28
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/30; C08G64/307
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
55 words
IN THE PROCESS FOR PREPARING POLYCARBONATE RESINS WHICH COMPRISES CONDENSING A DIHYDRIC PHENOL WITH A DIARYL CARBONATE AT ELEVATED TEMPERATURES AND UNDER REDUCED PRESSURE, THE IMPROVEMENT WHICH CONSISTS IN PURGING THROUGH THE REACTION MASS DURING THE CONDENSATION REACTION FROM ABOUT 0.1 TO ABOUT 20.0 WEIGHT PERCENT STEAM PER HOUR BASED ON THE WEIGHT OF REACTANTS.
Claim 2
Dependent Claim
55 words
IN THE PROCESS FOR PREPARING POLYCARBONATE RESINS WHICH COMPRISES CONDENSING A DIHYDRIC PHENOL WITH A DIARYL CARBONATE AT ELEVATED TEMPERATURES AND UNDER REDUCED PRESSURE, THE IMPROVEMENT WHICH CONSISTS IN PURGING THROUGH THE REACTION MASS DURING THE CONDENSATION REACTION FROM ABOUT 0.1 TO ABOUT 20.0 WEIGHT PERCENT STEAM PER HOUR BASED ON THE WEIGHT OF REACTANTS.
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) | 1969-10-31 | 1970-05-02 | 1970-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-10-31 | 1974-05-02 | 1974-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-10-31 | 1978-05-02 | 1978-11-01 | $7700.00 | Window Closed / Lapsed |