US2904534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of polyesters under controlled varying agitation
Assignee: Eastman Kodak Co
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Filing: 1956-05-29
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Granted: 1959-09-15
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Expires: 1976-05-29
Abstract
No abstract record available.
Inventors
- 👤 Jack L R Williams
- 👤 Kenneth R Dunham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:08
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
147 words
THE PROCESS WHICH COMPRISES HEATING A GLYCOL DIESTER OF AN AROMATIC DICARBOXYLIC ACID AT A TEMPERATURE ABOVE THE MELTING POINT OF SAID DIESTER, STIRRING THE RESULTING MELT AT AN INITIAL RATE OF AT LEAST 60 R.P.M., CONTINUING SAID HEATING AND STIRRING WHILE SAID DIESTER POLYMERIZES, SAID HEATING BEING SUFFICIENT TO MAINTAIN THE RESULTING POLYMER IN THE MOLTEN STATE THROUGHOUT THE POLYMERIZATION, CONTINUING SAID STIRRING AT SAID INITIAL RATE WHILE THE TORQUE NECESSARY TO MAINTAIN SAID INITIAL STIRRING RATE CONTINUES TO RISE, REDUCING SAID STIRRING RATE WHEN SAID TORQUE REACHES THE VICINITY OF 30 POUNDS BUT BEFORE SAID TORQUE EXCEEDS 30 POUNDS, THEREAFTER ADJUSTING THE RATE OF STIRRING TO SUCCESSIVELY LOWER STIRRING RATES AS THE TORQUE APPROACHES 30 POUNDS BUT BEFORE SAID TORQUE EXCEEDS 30 POUNDS AT THE STIRRING RATE BEING EMPLOYED, SAID POLYMERIZING BEING CARRIED OUT UNTIL A POLYESTER IS OBTAINED HAVING AN INHERENT VISCOSITY ABOVE 0.4.
Claim 2
Dependent Claim
147 words
THE PROCESS WHICH COMPRISES HEATING A GLYCOL DIESTER OF AN AROMATIC DICARBOXYLIC ACID AT A TEMPERATURE ABOVE THE MELTING POINT OF SAID DIESTER, STIRRING THE RESULTING MELT AT AN INITIAL RATE OF AT LEAST 60 R.P.M., CONTINUING SAID HEATING AND STIRRING WHILE SAID DIESTER POLYMERIZES, SAID HEATING BEING SUFFICIENT TO MAINTAIN THE RESULTING POLYMER IN THE MOLTEN STATE THROUGHOUT THE POLYMERIZATION, CONTINUING SAID STIRRING AT SAID INITIAL RATE WHILE THE TORQUE NECESSARY TO MAINTAIN SAID INITIAL STIRRING RATE CONTINUES TO RISE, REDUCING SAID STIRRING RATE WHEN SAID TORQUE REACHES THE VICINITY OF 30 POUNDS BUT BEFORE SAID TORQUE EXCEEDS 30 POUNDS, THEREAFTER ADJUSTING THE RATE OF STIRRING TO SUCCESSIVELY LOWER STIRRING RATES AS THE TORQUE APPROACHES 30 POUNDS BUT BEFORE SAID TORQUE EXCEEDS 30 POUNDS AT THE STIRRING RATE BEING EMPLOYED, SAID POLYMERIZING BEING CARRIED OUT UNTIL A POLYESTER IS OBTAINED HAVING AN INHERENT VISCOSITY ABOVE 0.4.
References Cited (Backward Citations)
US2758915A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-09-14 | 1963-03-16 | 1963-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-09-14 | 1967-03-16 | 1967-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-09-14 | 1971-03-16 | 1971-09-15 | $7700.00 | Window Closed / Lapsed |