Patent US2769460A successfully refreshed from Google Patents.
Patent US2938015A successfully refreshed from Google Patents.
US2938015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of polymeric glycol terephthalates of improved color
Assignee: EIDP Inc
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Filing: 1956-06-21
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Granted: 1960-05-24
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Expires: 1976-06-21
Abstract
No abstract record available.
Inventors
- 👤 William T Gormley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:13
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/83
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
86 words
THE PROCESS OF PREPARING SUBSTANTIALLY COLORLESS LINEAR POLYMERIC GLYCOL TEREPHTHALATE ESTERS WHICH COMPRISES POLYMERIZING AT ELEVATED TEMPERATURES AND UNDER REDUCED PRESSURE A GLYCOL TEREPHTHALATE IN THE PRESENCE OF A CATALYTIC AMOUNT OF A GLYCOL SOLUBLE ANTIMONY CATALYST, ADDING THERETO BEFORE THE GLYCOL TEREPHTHALATE ESTER HAS POLYMERIZED TO AN INTRINSIC VISCOSITY OF 0.1 AT LEAST ABOUT 0.05 MOL OF AN ACID PHOSPHATE SALT OF AN ALKALI METAL FOR EACH MOL OF CATALYST PRESENT, AND CONTINUING THE POLYMERIZATION UNTIL A LINEAR FIBER-FORMING POLYMERIC GLYCOL TEREPHTHALATE ESTER IS OBTAINED.
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) | 1963-05-24 | 1963-11-23 | 1964-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-24 | 1967-11-23 | 1968-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-24 | 1971-11-23 | 1972-05-24 | $7700.00 | Window Closed / Lapsed |