US3671497A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyurethane resins from hydroxy terminated perfluoro ethers
Assignee: National Aeronautics and Space Administration
•
Filing: 1970-12-18
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Granted: 1972-06-20
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Expires: 1990-12-18
Abstract
Abstract Hydroxy terminated perfluoro ethers and polyurethane resins incorporating the structure -CH2CF(CF3) (OCF2CF(CF3))mO(CF2)pO(CF(CF3)CF2O) nCF(CF3)CH2where p is an integer of 2 to 12 and M AND N ARE INTEGERS WHOSE SUM IS FROM 0 TO 20.
Inventors
- 👤 Eugene C Stump Jr
- 👤 Stephen Eugene Rochow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:35
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/50; C08G18/5003; C08G18/5015; Y; Y10; Y10S; Y10S528/00; Y10S528/906
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
18 words
The resin of claim 1 where the mole ratio of diisocyanate to diol is from 1:1 to 3:1.
Claim 2
Dependent Claim
18 words
The resin of claim 2 where the mole ratio of diisocyanate to diol is from 1:1 to 2:1.
Claim 3
Dependent Claim
24 words
The resin of claim 1 where the diisocyanate is selected from the group consisting of tetrafluoro-m-phenylene diisocyanate, tetrafluoro-p-phenylene diisocyanate, perfluorotrimethylene diisocyanate, and 1-chloro-2,4-diisocyanato-3, 5,6-trifluorobenzene.
References Cited (Backward Citations)
US3475384A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |