US5238732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Waterproof breathable polyurethane membranes and porous substrates protected therewith
Assignee: BAYBANK
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Filing: 1993-01-11
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Granted: 1993-08-24
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Expires: 2013-01-11
Abstract
Abstract Disclosed herein are polyurethane compositions specifically adapted to produce non-porous membranes exhibiting waterproof and water vapor transmissible characteristics. The membranes can be produced as free standing products or can be produced as coatings on porous substrates to confer similar properties to such substrates. Also disclosed are coated fabrics and fabric laminates utilizing the membranous coatings of the invention and exhibiting waterproof and water vapor transmissible characteristics. Such coated fabrics and fabric laminates find utility in the fabrication of tenting, rainwear and other garments where waterproofness, coupled with breathability, are important features.
Inventors
- 👤 Sundaram Krishnan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:45
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/0838; C08G18/0842; C08G18/0847; C08G18/0852; B; B32; B32B; B32B27/00; B32B27/40; B32B5/00; B32B5/22; B32B5/24; B32B5/26; C08G18/28; C08G18/40; C08G18/48; C08G18/4804; C08G18/61; D; D06; D06M; D06M15/00; D06M15/19; D06M15/37; D06M15/564; D06M15/568; D06M15/643; D06M17/00; D06M17/04; D06M17/10; D06N; D06N3/00; D06N3/12; D06N3/14; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31562; Y10T442/00; Y10T442/20; Y10T442/2139; Y10T442/2221; Y10T442/2246
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
153 words
A method for rendering a porous substrate waterproof and water vapor transmissible which comprises disposing over the surface of said substrate a waterproof, water vapor transmissible non-porous polyurethane membrane prepared as a reaction product of: (a) an organic polyisocyanate; (b) a polyalkylene ether glycol wherein the number of carbon atoms of the alkylene radical thereof is 2; (c) at least one polyalkylene ether glycol wherein the number of carbon atoms of the alkylene radical thereof is at least 3; and (d) an isocyanate reactive hydroxyl group-containing polydimethylsiloxane having a functionality of at least 2; the mole ratio of the polyalkylene ether glycol of (a) to the at least one polyalkylene ether glycol of (b) being within the range of from 1.5:0.5 to 0.5:1.5 and the mole ratio of said isocyanate reactive polydimethylsiloxane to the total of said polyalkylene ether glycols of (b) and (c) being within the range of from 0.1:1 to 0.3:1.
Claim 2
Independent Claim
153 words
A method for rendering a porous substrate waterproof and water vapor transmissible which comprises disposing over the surface of said substrate a waterproof, water vapor transmissible non-porous polyurethane membrane prepared as a reaction product of: (a) an organic polyisocyanate; (b) a polyalkylene ether glycol wherein the number of carbon atoms of the alkylene radical thereof is 2; (c) at least one polyalkylene ether glycol wherein the number of carbon atoms of the alkylene radical thereof is at least 3; and (d) an isocyanate reactive hydroxyl group-containing polydimethylsiloxane having a functionality of at least 2; the mole ratio of the polyalkylene ether glycol of (a) to the at least one polyalkylene ether glycol of (b) being within the range of from 1.5:0.5 to 0.5:1.5 and the mole ratio of said isocyanate reactive polydimethylsiloxane to the total of said polyalkylene ether glycols of (b) and (c) being within the range of from 0.1:1 to 0.3:1.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said membrane is continuously bonded to said substrate.
Claim 4
Dependent Claim
54 words
The method of claim 2 wherein said membrane is produced by coating of said substrate with a solution of the uncured polyurethane composition dissolved in a fugitive compatible solvent, driving off the solvent of said coating, thereby to produce an uncured non-porous membrane disposed over and bonded to said substrate, and curing the membrane
Claim 5
Dependent Claim
11 words
The method of claim 3 wherein said substrate is a fabric.
Claim 6
Dependent Claim
23 words
The method of claim 1 wherein said membrane is continuously adhered to said substrate by means of a water vapor transmissible polyurethane adhesive.
Claim 7
Dependent Claim
11 words
The method of claim 5 wherein said substrate is a fabric.
Claim 8
Dependent Claim
11 words
The method of claim 1 wherein said substrate is a fabric.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-23 | 1997-02-22 | 1997-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-23 | 2001-02-22 | 2001-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-23 | 2005-02-22 | 2005-08-24 | $7700.00 | Window Closed / Lapsed |