Patent US2811512A successfully refreshed from Google Patents.
US2811512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organic polyesters from tetrahydrofurans and dicarboxylic acids
Assignee: EIDP Inc
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Filing: 1953-07-15
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Granted: 1957-10-29
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Expires: 1973-07-15
Abstract
No abstract record available.
Inventors
- 👤 Paul R Austin
- 👤 Oliver W Cass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:38
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/52; C08G63/56; C08G63/58; C08G63/40; C08G63/42
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
79 words
THE PROCESS OF PRODUCING A LINEAR POLYESTER WHICH COMPRISES REACTING IN EQUIMOLAR PROPORTIONS A MEMBER OF THE GROUP CONSISTING OF TETRAHYDROFURAN AND METHYL TETRAHYDROFURAN WITH AN ACID ANHYDRIDE CHOSEN FROM THE GROUP CONSISTING OF MALEIC, SUCCINIC, PHTHALIC AND TETRAHYDROPHTHALIC ACID ANHYDRIDES IN THE PRESENCE OF ABOUT 1 TO 2 MOLE PERCENT OF A MEMBER OF THE GROUP CONSISTING OF BORON TRIFLUORIDE, BORON TRIFLUORIDE ETHERATE, BORICNY OXIDE, STANNIC CHLORIDE, ALULMINUM CHLORIDE, ANTIMONY PENTACHLORIDE, SULFURIC ACID, FERRIC CHLORIDE AND ZINC CHLORIDE.
Claim 2
Dependent Claim
79 words
THE PROCESS OF PRODUCING A LINEAR POLYESTER WHICH COMPRISES REACTING IN EQUIMOLAR PROPORTIONS A MEMBER OF THE GROUP CONSISTING OF TETRAHYDROFURAN AND METHYL TETRAHYDROFURAN WITH AN ACID ANHYDRIDE CHOSEN FROM THE GROUP CONSISTING OF MALEIC, SUCCINIC, PHTHALIC AND TETRAHYDROPHTHALIC ACID ANHYDRIDES IN THE PRESENCE OF ABOUT 1 TO 2 MOLE PERCENT OF A MEMBER OF THE GROUP CONSISTING OF BORON TRIFLUORIDE, BORON TRIFLUORIDE ETHERATE, BORICNY OXIDE, STANNIC CHLORIDE, ALULMINUM CHLORIDE, ANTIMONY PENTACHLORIDE, SULFURIC ACID, FERRIC CHLORIDE AND ZINC CHLORIDE.
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) | 1960-10-28 | 1961-04-29 | 1961-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-28 | 1965-04-29 | 1965-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-28 | 1969-04-29 | 1969-10-29 | $7700.00 | Window Closed / Lapsed |