US4942214A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible breathable polyurethane coatings and films, and the prepolymers from which they are made
Assignee: W.L. Gore and Associates Inc
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Filing: 1988-06-29
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Granted: 1990-07-17
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Expires: 2008-06-29
Abstract
Abstract The invention relates to flexible breathable polyurethane coatings and films and to the prepolymers from which they are formed. These prepolymers are isocyanate-capped poly (alkylene oxide) glycol polyurethanes with low viscosities and low freezing points. The difunctional nature of the random copolymers of ethylene oxide and prepylene oxide added to simple diols provide the low viscosity and low freezing points; high levels of ethylene oxide in the polyol provides the breathability.
Inventors
- 👤 Dilip J. Sakhpara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:15
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/4833; C08G18/4837; C08G18/08; C08G18/10; Y; Y10; Y10S; Y10S521/00; Y10S521/914
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
96 words
Low viscosity, low freezing point isocyanate-capped prepolymers for making breathable coatings and films comprising the reaction product of: (a) a difunctional poly(oxyalkylene) glycol with a molecular weight between 1000 and 4000, said difunctional poly(oxyalkylene) glycol being a random copolymer of ethylene oxide and propylene oxide added to ethylene glycol, propylene glycol or 1, 4-butanediol; the oxyethylene content of the difunctional poly(oxyalkylene) glycol being between 60% and 95% by weight, and (b) a polyisocyanate with a functionality between 2.0 and 2.2, said polyisocyanate being selected from the class consisting of diphenyl methane diisocyanate and dicyclohexyl methane diisocyanate.
Claim 2
Dependent Claim
96 words
Low viscosity, low freezing point isocyanate-capped prepolymers for making breathable coatings and films comprising the reaction product of: (a) a difunctional poly(oxyalkylene) glycol with a molecular weight between 1000 and 4000, said difunctional poly(oxyalkylene) glycol being a random copolymer of ethylene oxide and propylene oxide added to ethylene glycol, propylene glycol or 1, 4-butanediol; the oxyethylene content of the difunctional poly(oxyalkylene) glycol being between 60% and 95% by weight, and (b) a polyisocyanate with a functionality between 2.0 and 2.2, said polyisocyanate being selected from the class consisting of diphenyl methane diisocyanate and dicyclohexyl methane diisocyanate.
Claim 3
Dependent Claim
36 words
A prepolymer as described in claim 1 wherein the ethylene oxide content of the difunctional poly(oxyalkylene) glycol is between 70% and 90%, the remainder being propylene oxide and the molecular weight is between 1500 and 3000.
Claim 4
Dependent Claim
27 words
A prepolymer as described in claim 1 in which the reactants are used in a ratio of molar equivalents of NCO to OH of 1.5 to 4.0.
Claim 5
Dependent Claim
24 words
A prepolymer as described in claim 1 in which the reactants are used in a molar equivalent ratio of NCO/OH of 2.0 to 3.0.
Claim 6
Dependent Claim
25 words
A prepolymer as described in claim 3 or 4 having a viscosity of 15,000 cps. or less and a freezing point of below 0° C.
Claim 7
Dependent Claim
41 words
Breathable coatings or films formed from the low melting, low viscosity isocyanate-capped prepolymers described in claim 5 which are cured with or without catalysts by: (a) addition of alkanolamines, polyamines or diamine carbamate curing agents, or (b) by atmospheric borne moisture.
Claim 8
Dependent Claim
42 words
Breathable coatings and films as described in claim 6 which have moisture vapor transmission rates of at least 5000 g/m 2 /24 hours when such coatings or films are 5 to 10 mil. thick and the MVTR is measured as described herein.
References Cited (Backward Citations)
US4127516A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |