Patent US2534028A successfully refreshed from Google Patents.
US2534028A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of polyethylene terephthalate
Assignee: EIDP Inc
•
Filing: 1948-05-13
•
Granted: 1950-12-12
•
Expires: 1968-05-13
Abstract
No abstract record available.
Inventors
- 👤 Izard Emmette Farr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:42
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/85
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
96 words
A POROCESS FOR PRODUCING FIBER-FORMING POLYETHYLENE TEREPHTHALATE WHICH COMPRISES REACTING ETHYLENE GLYCOL AND DIMETHYL TEREPHTHALATE IN THE PRESENCE OF A CATALYTIC AMOUTN OF LITHARGE AT A TEMPERATURE OF FROM 140* TO 220*C UNTIL NO FURTHER METHANOL IS LIBERATED, AND THEREAFTER CONTINUING REACTION IN THE PRESENCE OF SAID LITHARGE AT TEMPERATURE OF FROM 230* TO 290*C., AND AT A PRESSURE OF FROM 0.1-20 MILLIMETERS OF MERCURY UNTIL A FIBER-FORMING LINEAR POLYESTER IS FORMED WHICH HAS AN INTRINSIC VISCOSITY OF AT LEAST 0.8 AND CONTAINS NOT OVER 3.0 MOL PER CENT OF DIETHYLENE GLYCOL IN THE POLYME CHAIN.
Claim 2
Dependent Claim
96 words
A POROCESS FOR PRODUCING FIBER-FORMING POLYETHYLENE TEREPHTHALATE WHICH COMPRISES REACTING ETHYLENE GLYCOL AND DIMETHYL TEREPHTHALATE IN THE PRESENCE OF A CATALYTIC AMOUTN OF LITHARGE AT A TEMPERATURE OF FROM 140* TO 220*C UNTIL NO FURTHER METHANOL IS LIBERATED, AND THEREAFTER CONTINUING REACTION IN THE PRESENCE OF SAID LITHARGE AT TEMPERATURE OF FROM 230* TO 290*C., AND AT A PRESSURE OF FROM 0.1-20 MILLIMETERS OF MERCURY UNTIL A FIBER-FORMING LINEAR POLYESTER IS FORMED WHICH HAS AN INTRINSIC VISCOSITY OF AT LEAST 0.8 AND CONTAINS NOT OVER 3.0 MOL PER CENT OF DIETHYLENE GLYCOL IN THE POLYME CHAIN.
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) | 1953-12-11 | 1954-06-12 | 1954-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-12-11 | 1958-06-12 | 1958-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-12-11 | 1962-06-12 | 1962-12-12 | $7700.00 | Window Closed / Lapsed |