US2932625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of polyesters
Assignee: —
•
Filing: —
•
Granted: 1960-04-12
•
Expires: 1977-04-12
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:57
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
106 words
A PROCESS FOR MAKING HIGHLY POLYMER POLYMETHYLENE TEREPHTHALATES BY POLYCONDENSATION OF THE ESTERINTERCHARGE REACTION PRODUCT WHICH HAS BEEN PREPARED BY REACTING ETHYLENE GLYCOL UNDER ATMOSPHERE PRESSURE WITH A DI-LOWER ALKYL ESTER OF TEREPHTHALIC ACID AT AN ESTER-INTERCHANGE TEMPERATURE RISING IN EXCESS OF ABOUT 210*C. BUT LESS THAN ABOUT 300*C. WITH THE MOLAR RATIO OF SAID GLYCOL TO SAID DI-LOWER ALKYL TEREPHTHALATE ESTER BETWEEN 1.3:1 AND 2:1, THEREAFTER REDUCING THE PRESSURE TO LESS THAN ABOUT 1 MM. OF MERCURY WITHOUT REDUCING THE TEMPERATURE, AND CONDUCTING SAID POLYCONDENSATION STEP AT A TEMPERATURE OF ABOUT 275*C. UNTIL AN IN INTRINSIC VISCOSITY OF FROM ABOUT 0.6 TO 0.7 IS ATTAINED.
Claim 2
Dependent Claim
106 words
A PROCESS FOR MAKING HIGHLY POLYMER POLYMETHYLENE TEREPHTHALATES BY POLYCONDENSATION OF THE ESTERINTERCHARGE REACTION PRODUCT WHICH HAS BEEN PREPARED BY REACTING ETHYLENE GLYCOL UNDER ATMOSPHERE PRESSURE WITH A DI-LOWER ALKYL ESTER OF TEREPHTHALIC ACID AT AN ESTER-INTERCHANGE TEMPERATURE RISING IN EXCESS OF ABOUT 210*C. BUT LESS THAN ABOUT 300*C. WITH THE MOLAR RATIO OF SAID GLYCOL TO SAID DI-LOWER ALKYL TEREPHTHALATE ESTER BETWEEN 1.3:1 AND 2:1, THEREAFTER REDUCING THE PRESSURE TO LESS THAN ABOUT 1 MM. OF MERCURY WITHOUT REDUCING THE TEMPERATURE, AND CONDUCTING SAID POLYCONDENSATION STEP AT A TEMPERATURE OF ABOUT 275*C. UNTIL AN IN INTRINSIC VISCOSITY OF FROM ABOUT 0.6 TO 0.7 IS ATTAINED.
References Cited (Backward Citations)
US2465319A
Cited
US2643989A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-04-12 | 1963-10-12 | 1964-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-12 | 1967-10-12 | 1968-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-12 | 1971-10-12 | 1972-04-12 | $7700.00 | Window Closed / Lapsed |