Liquid water resistant and water vapor permeable garments

Abstract

A water resistant garment having regions of high MVTR while maintaining water resistance. The garment has a nanofiber layer bonded to, and in a face-to-face relationship with, a fabric layer. Optionally a second fabric layer is bonded adjacent to and in a face-to-face relationship with the nanofiber layer and on the opposite side of the nanofiber layer to the first fabric layer. The garment has regions having a Frazier air permeability of no greater than about 25 cfm/ft 2 , an MVTR per ASTM E-96B method of greater than about 500 g/m 2 /day and a hydrohead of at least about 50 cmwc.

1 . A waterproof, breathable garment having the ability to pass moisture vapor while protecting the wearer from water comprising a composite fabric of a first outer fabric layer adjacent to and in a face-to-face relationship with a nanofiber layer, wherein the nanofiber layer comprises at least one porous layer of polymeric nanofibers having a number average diameter between about 50 nm to about 1000 nm, a basis weight of between about 1 g/m 2  and about 100 g/m 2 , and the composite fabric has a Frazier air permeability of between about 1.2 m 3 /m 2 /min and about 7.6 m 3 /m 2 /min, an MVTR of greater than about 500 g/m 2 /day, and a hydrostatic head of at least about 50 cm of water. 
   
   
       2 . The garment of  claim 1  wherein the nanofiber layer and the first fabric layer are bonded to each other over a fraction of their surfaces. 
   
   
       3 . The garment of  claim 2  wherein a solvent-based adhesive is used to bond the layers. 
   
   
       4 . The garment of  claim 2  wherein the nanofiber layer is electrospun directly onto the surface of the first fabric layer and residual solvent from the electrospinning process is used to bond the layers. 
   
   
       5 . The garment of  claim 1  wherein the nanofiber layer comprises nanofibers of a polymer selected from the group consisting of polyacetals, polyamides, polyesters, cellulose ethers, cellulose esters, polyalkylene sulfides, polyarylene oxides, polysulfones, modified polysulfone polymers and combinations thereof. 
   
   
       6 . The garment of  claim 1  wherein the nanofiber layer comprises nanofibers of a polymer selected from the group consisting of poly(vinylchloride), polymethylmethacrylate, polystyrene, and copolymers thereof, poly(vinylidene fluoride), poly(vinylidene chloride), polyvinylalcohol in crosslinked and non-crosslinked forms. 
   
   
       7 . The garment of  claim 5  wherein the polymer is selected from the group consisting of nylon-6, nylon-6,6, and nylon 6,6-6,10. 
   
   
       8 . The garment of  claim 1  wherein the nanofiber layer is calendered. 
   
   
       9 . The garment of  claim 8  wherein the nanofiber layer is calendered while in contact with the first fabric layer. 
   
   
       10 . The garment of  claim 1  wherein the nanofiber layer is treated with a fluorinated surfactant. 
   
   
       11 . The garment of  claim 1  wherein the first fabric layer is woven from a material selected from the group consisting of nylon, cotton, wool, silk, polyester, polyacrylic, polyolefin, and combinations. 
   
   
       12 . The garment of  claim 1  wherein the first fabric layer is woven from fibers that have a tenacity of less than about 8 g/Denier (gpd)).