Patent ID: 6273271
Filing Date: 2001-08-14
Classification: B01D,C08J,Y10T

Abstract:
The process for forming a porous membrane product comprising a thin porous nondewetting polymeric substrate deposited thereon over its entire surface a bound perfluorocarbon copolymer composition, said perfluorocarbon copolymer composition containing hydrophilic functional groups and being substantially insoluble in a solvent or diluent for solvated unbound perfluorocarbon copolymer composition and wherein said porous membrane product has essentially the same permeability as the porous polymeric substrate which comprises:a) contacting a solution containing a perfluorocarbon copolymer composition with said polymer substrate to effect deposition and binding of said perfluorocarbon copolymer composition onto said polymer substrate,b) contacting said polymer substrate having bound and unbound perfluorocarbon copolymer composition from steep (a) with a solvent, diluent or dispersant for unbound perfluorocarbon copolymer composition to selectively remove unbound perfluorocarbon copolymer composition from said polymer substrate while substantially avoiding removal of bound perfluorocarbon copolymer composition from said polymer substrate andc) heat treating said polymer substrate having said bound perfluorocarbon copolymer composition on said surface.