Patent US240349A successfully refreshed from Google Patents.
Patent US3755265A successfully refreshed from Google Patents.
US3755265A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Highly fluorinated polyurethanes
Assignee: National Aeronautics and Space Administration
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Filing: 1972-04-04
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Granted: 1973-08-28
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Expires: 1992-04-04
Abstract
Abstract Polyurethanes having the repeating unit: WHERE N IS AN INTEGER OF 1 TO 12, P IS AN INTEGER OF 2 TO 23, Y IS AN INTEGER OF 1 TO 1000, AND R is any radical suitable to link isocyanate groups and is preferably selected from the group consisting of alkylene and halogen substituted alkylene radicals of four to 12 C atoms, substituted and unsubstituted phenylene groups of up to 20 C atoms.
Inventors
- 👤 J Fletcher
- 👤 E Stump
- 👤 S Rochow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:08
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: 6
Claim 1
Independent Claim
37 words
The polyurethane of claim 1 where R is selected from the group consisting of alkylene and halogen substituted alkylene groups of four to 12 C atoms, substituted and unsubstituted phenylene groups of up to 20 C atoms.
Claim 2
Dependent Claim
37 words
A polyurethane formed from the reaction at a 1:1 to 3:1 mole ratio of a diisocyanate with a diol having the formula: HOCH2(CF(CF3)O(CF2)pOCF(CF3))nCH2OH where n is from 1 to 12 and p is from 2 to 23.
Claim 3
Dependent Claim
18 words
The polyurethane of claim 3 where the mole ratio of diisocyanate to diol is from 1:1 to 2:1.
Claim 4
Dependent Claim
45 words
The polyurethane of claim 3 where the diisocyanate has the general formula: OCNRNCO, where R is selected from the group consisting of alkylene and halogen substituted alkylene groups of four to 12 C atoms, substituted and unsubstituted phenylene groups of up to 20 C atoms.
Claim 5
Dependent Claim
20 words
The polyurethane of claim 3 wherein the diisocyanate is selected from the class consisting of tetrafluoro-m-phenylene diisocyanate and tetrafluoro-p-phenylene diisocyanate.
Claim 6
Dependent Claim
8 words
The polyurethane of claim 3, where p 5.
References Cited (Backward Citations)
US3574770A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |