Gas permeable fabric

Abstract

A gas permeable fabric made from a porous substrate that is treated with a composition comprising a fluoropolymer and a rigidizing, film-forming material is disclosed.

What is claimed is:  
     
         1 . A gas permeable fabric comprising a porous substrate treated with a composition comprising a fluoropolymer and a rigidizing film forming material.  
     
     
         2 . A gas permeable fabric according to  claim 1 , wherein the film forming material is a polyamideimide.  
     
     
         3 . A gas permeable fabric according to  claim 1  or  2 , wherein the composition further comprises mica particles, mica particles coated with pigment or metal flake; and blends thereof.  
     
     
         4 . A gas permeable fabric according to any one of  claims 1  to  3  wherein the fluoropolymer is a polytetrafluoroethylene or a copolymer of tetrafluoroethylene with one or more of 1) a perfluorinated vinyl ether, 2) perfluoronated ethylenepropylene, 3) hexafluoropropylene and 4) vinylidene fluoride; and blends thereof.  
     
     
         5 . A gas permeable fabric according to any one of  claims 1  to  4  wherein the fabric is made from fibers selected from a meta-aramid, a para-aramid, an aramid copolymer, a polyamideimide, a polyoxadiazole, a polyimide, a polyetheretherketone, a polyetherketoneketone, a polybenzimidazole, a polytetrafluorethylene, a glass, a ceramic, and blends thereof.  
     
     
         6 . A gas permeable fabric according to  claim 1  or  2  wherein the fabric is made from fibers selected from a polyamide, a polyacrylonitrile, a polyester, a polyphenylensulfide, a polyetherimide, a viscose, a cotton or a modified cellulosic, and blends thereof.  
     
     
         7 . A gas permeable fabric according to  claim 6  wherein the fluoropolymer is dispersed in water.  
     
     
         8 . A gas permeable fabric according to any one of the preceding claims wherein the fabric is formed into a desired shape.  
     
     
         9 . A gas permeable fabric according to  claim 8 , wherein the fabric is a filter.  
     
     
         10 . A method of making a gas permeable fabric according to any one of the preceding claims comprising applying a composition containing a fluoropolymer and a film forming material to a porous substrate, forming the substrate into a desired shape, and curing the composition.  
     
     
         11 . A fiber having resistance to degradation at a temperature in the range of 280° C. to 365° C. for a period of 10 minutes comprising a gas permeable fabric of a porous substrate made from fibers capable of withstanding degradation in said temperature range for said time period, said fibers treated with a composition comprising fluoropolymer and a rigidizing film forming material.  
     
     
         12 . The fiber of  claim 11  wherein the fibers are selected from the group consisting of meta-aramid, para-aramid, aramid copolymer, polyamideimide, polyoxadiazole, polyimide, polyetheretherketone, polyetherketoneketone, polybenimidazole, polytetrafluoroethylene, glass, ceramic, and blends thereof.  
     
     
         13 . The fiber of  claim 12  wherein the fibers are selected from the group consisting of meta-aramid, para-aramid, polytetrafluoroethylene, polytetrafluoroethylene-glass blend, and polyimide.  
     
     
         14 . The fiber of  claim 11  wherein the composition further comprises mica particles, mica particles coated with pigment or metal flake; and blends thereof.