# US 7,608,186 B2 · Coated asymmetric membrane system having oleophobic and hydrophilic properties > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,186 B2 - Document ID: US7608186B2 - Status: Granted - Kind: B2 - Application number: 11/694,590 - Filed: 2007-03-30 - Published: 2008-10-02 - Granted: 2009-10-27 - Earliest claimed: 2007-03-30 - Assignees: General Electric Company - Inventors: Vishal Bansal; Hieu Minh Duong - Web page: https://patentgrep.com/patent/US7608186B2 ## CPC - B32B 27/00: Layered products comprising {a layer of} synthetic resin {(fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18)} - D06M 15/277: containing fluorine - D06M 15/333: of vinyl acetate; Polyvinylalcohol - D06M 15/3562: {containing nitrogen} - D06M 15/576: containing fluorine - D06M 2101/22: Polymers or copolymers of halogenated mono-olefins - Y10T 428/24998: Composite has more than two layers - Y10T 428/249991: Synthetic resin or natural rubbers - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - D06M: TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A porous membrane assembly includes, in an exemplary embodiment, a porous membrane substrate having hydrophobic properties. The membrane substrate includes a first side, an opposing second side and a plurality of pores extending therethrough. The membrane substrate also includes a discontinuous layer of an oleophobic coating applied to the first side so that the plurality of pores in the first side are substantially free of the oleophobic coating, and a continuous layer of an amine containing hydrophilic polymer coating applied to the second side of the membrane substrate. ## Claims ### Claim 1 A porous membrane assembly comprising: a first porous membrane substrate having hydrophobic properties, said first membrane substrate comprising a first side, an opposing second side and a plurality of pores extending from said first side to said second side; a discontinuous layer of an oleophobic coating applied to said first side of said first membrane substrate so that said plurality of pores in said first side are substantially free of said oleophobic coating; a second porous membrane substrate having a first side, an opposing second side, and a plurality of pores extending therethrough, said second side of said first membrane substrate bonded to said first side of said second membrane substrate by a discontinuous layer of an adhesive; and a continuous layer of an amine containing hydrophilic polymer coating applied to said second side of said second membrane substrate. ### Claim 2 (depends on 1) A porous membrane assembly in accordance with claim 1 wherein said first and second porous membrane substrates comprises expanded polytetrafluoroethylene, woven polytetrafluoroethylene, or non-woven polytetrafluoroethylene. ### Claim 3 (depends on 1) A porous membrane assembly in accordance with claim 1 wherein said first and second porous membrane substrates comprises expanded polytetrafluoroethylene. ### Claim 4 (depends on 1) A porous membrane assembly in accordance with claim 1 wherein said amine containing hydrophilic polymer coating comprises a polyvinyl alcohol-coamine polymer. ### Claim 5 (depends on 1) A porous membrane assembly in accordance with claim 1 wherein said oleophobic coating comprises a fluorinated polymer. ### Claim 6 (depends on 5) A porous membrane assembly in accordance with claim 5 wherein said fluorinated polymer is selected from the group consisting of fluorinated urethane polymers, perfluro alkyl acrylic copolymers, perfluro alkyl methacrylic copolymers, and random copolymers of fluorinated acrylate, fluorinated methacrylate, fluorinated, fluorinated n-alkyl acrylate, and fluorinated n-alkyl methacrylate. ### Claim 7 (depends on 1) A porous membrane assembly in accordance with claim 1 wherein said plurality of pores are about 0.01 μm to about 10 μm. ### Claim 8 (depends on 1) A porous membrane assembly in accordance with claim 1 wherein said amine containing hydrophilic polymer coating additionally fills said pores of said second membrane substrate. ### Claim 9 A method of manufacturing a porous membrane assembly, said method comprising: providing a first porous membrane substrate having hydrophobic properties, the first membrane substrate comprising a first side, an opposing second side and a plurality of pores extending therethrough; forming a discontinuous layer of an oleophobic coating by applying the oleophobic coating to the first side of the first membrane substrate so that the plurality of pores in the first side are substantially free of the oleophobic coating; bonding a second porous membrane substrate having a first side, an opposing second side, and a plurality of pores extending therethrough, to the first membrane substrate, the second side of the first membrane substrate bonded to the first side of the second membrane substrate with a discontinuous layer of an adhesive; and forming a continuous layer of an amine containing hydrophilic polymer coating by applying the amine containing hydrophilic polymer coating to the second side of the second membrane substrate. ### Claim 10 (depends on 9) A method in accordance with claim 9 wherein the first and second porous membrane substrate comprises expanded polytetrafluoroethylene, woven polytetrafluoroethylene, or non-woven polytetrafluoroethylene. ### Claim 11 (depends on 9) A method in accordance with claim 9 wherein the first and second membrane substrates comprise expanded polytetrafluoroethylene membrane substrates. ### Claim 12 (depends on 9) A method in accordance with claim 9 wherein the amine containing hydrophilic polymer coating comprises a polyvinyl alcohol-coamine polymer. ### Claim 13 (depends on 9) A method in accordance with claim 9 wherein the oleophobic coating comprises a fluorinated polymer. ### Claim 14 (depends on 13) A method in accordance with claim 13 wherein the fluorinated polymer is selected from the group consisting of fluorinated urethane polymers, perfluro alkyl acrylic copolymers, perfluro alkyl methacrylic copolymers, and random copolymers of fluorinated acrylate, fluorinated methacrylate, fluorinated, fluorinated n-alkyl acrylate, and fluorinated n-alkyl methacrylate. ### Claim 15 (depends on 9) A method in accordance with claim 9 wherein the plurality of pores are about 0.01 μm to about 10 μm. ### Claim 16 (depends on 9) A method in accordance with claim 9 wherein forming a continuous layer of an amine containing hydrophilic polymer coating comprises: forming a continuous layer of an amine containing hydrophilic polymer coating by applying the amine containing hydrophilic polymer coating to the second membrane substrate so that the pores of the second membrane substrate are additionally filled with the amine containing hydrophilic polymer coating.