US4849458A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Segmented polyether polyurethane
Assignee: MATRIX MEMBRANES Inc
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Filing: 1988-06-17
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Granted: 1989-07-18
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Expires: 2008-06-17
Abstract
Abstract A hydrophilic, segmented polyether polyurethane-urea that exhibits an increase in tensile strength and elongation when wet with water and is capable of forming visually clear films permeable to water vapor is disclosed.
Inventors
- 👤 Andrew M. Reed
- 👤 Ian N. Askill
- 👤 Willis W. Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:57
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/74; C08G18/76; C08G18/7657; C08G18/7664; C08G18/7671; C08G18/08; C08G18/10; C08G18/12; C08G18/28; C08G18/40; C08G18/48; C08G18/4804; C08G18/4808
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
61 words
A hydrophilic but water-insoluble, segmented polyether polyurethane-urea having a wet strength greater than dry strength and capable of forming a visually clear film; said polyurethane-urea being the reaction product of a prepolymer derived from a stoichiometric excess of a diisocyanate reacted with an admixture of polyalkylene ether glycols each having different-length alkyleneoxy segments, and extended with a difunctional amine chain extender.
Claim 2
Dependent Claim
61 words
A hydrophilic but water-insoluble, segmented polyether polyurethane-urea having a wet strength greater than dry strength and capable of forming a visually clear film; said polyurethane-urea being the reaction product of a prepolymer derived from a stoichiometric excess of a diisocyanate reacted with an admixture of polyalkylene ether glycols each having different-length alkyleneoxy segments, and extended with a difunctional amine chain extender.
Claim 3
Dependent Claim
22 words
The segmented polyether polyurethane-urea of claim 1 wherein said admixture of polyalkylene ether glycols is constituted by polytetramethylene glycol and polyethylene glycol.
Claim 4
Dependent Claim
25 words
The segmented polyether polyurethane-urea of claim 2 wherein polytetramethylene glycol and polyethylene glycol are present in the admixture in a mole ratio of about 3:1.
Claim 5
Dependent Claim
40 words
The segmented polyether polyurethane-urea of claim 1 wherein said relatively shorter segment glycol have a molecular weight in the range of about 1000 to about 3,000 and said relatively longer segment glycol has molecular weight of at least about 800.
Claim 6
Dependent Claim
19 words
The segmented polyether polyurethane-urea of claim 1 wherein said glycols have a number average molecular weight of about 2000.
Claim 7
Dependent Claim
18 words
The segmented polyether polyurethane-urea of claim 1 wherein said glycols have substantially the same number average molecular weight.
Claim 8
Dependent Claim
49 words
The segmented polyether polyurethane-urea of claim 6 wherein the polyalkylene ether glycol having the relatively shorter alkyleneoxy segments constitutes at least about 10 mole percent of the admixture and the polyalkylene ether glycol having the relatively longer alkyleneoxy segments constitutes more than about 50 mole percent of the admixture.
Claim 9
Dependent Claim
39 words
The segmented polyether polyurethane-urea of claim 1 wherein the polyalkylene ether glycol having the relatively longer alkyleneoxy segments and the polyalkylene ether glycol having the relatively shorter alkyleneoxy segments are present in a mole ratio of about 3:1, respectively.
Claim 10
Dependent Claim
20 words
The segmented polyether polyurethane-urea of claim 8 wherein both of said glycols have substantially the same number average molecular weight.
Claim 11
Dependent Claim
19 words
The segmented polyether polyurethane-urea of claim 9 wherein said glycols have a number average molecular weight of about 2,000.
References Cited (Backward Citations)
US3963681A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |