Waterproof breathable polyurethane membranes and porous substrates protected therewith
First Claim
1. A waterproof, water vapor transmissible non-porous polyurethane membrane comprising the 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 with the range of from 0.1;
1 to 0.3;
1.
1 Assignment
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Accused Products
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.
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Citations
12 Claims
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1. A waterproof, water vapor transmissible non-porous polyurethane membrane comprising the reaction product of:
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(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 with the range of from 0.1;
1 to 0.3;
1. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification