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AssigneeE. I. Du Pont de Nemours and Company
InventorWalther G. Grot
Estimating the term…
A process is provided for making a liquid composition of a perfluorinated polymer having sulfonic acid or sulfonate groups in a liquid medium by contacting the polymer with a mixture of 25 to 100% by weight of water and 0 to 75% by weight of a second liquid component such as a lower alcohol, e.g., propanol or methanol, at a temperature of at least 180.degree. C. (at least 240.degree. C. when about 90% to 100% water is used), in a closed system. The liquid composition made by this process, or modified liquid products prepared therefrom, are used in coating various substrates, in casting films, and in repairing perfluorinated ion exchange films and membranes. The process is also useful in recovering perfluorinated polymer having sulfonic acid or sulfonate groups from scraps and used articles made of such polymer or containing such polymer as a component part thereof.
A process for making a coated article which comprises applying to a substrate a liquid composition of a perfluorinated ion exchange polymer having --SO.sub.3 M functional groups wherein M is H, Na, K or NR.sub.4, and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, in a liquid medium, said liquid composition being liquid at room temperature, said liquid composition being prepared by the process comprising contacting a said polymer having an equivalent weight in the range of 1025 to 1500 with a mixture comprising 20 to 90% by weight of water and 10 to 80% by weight of at least one member of the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane and acetonitrile at a temperature in the range of about 180.degree. and 300.degree. C. and below the critical temperature(s) of said member(s) employed, for at least 0.5 hour in a closed vessel, and separating from said liquid composition any lower density liquid phase present, followed by drying.
A process for making a coated article which comprises applying to a substrate a liquid product prepared from a liquid composition of a perfluorinated ion exchange polymer having --SO.sub.3 M functional groups wherein M is H, Na, K or NR.sub.4, and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, in a liquid medium, said liquid composition being liquid at room temperature, said liquid composition being prepared by the process comprising contacting a said polymer having an equivalent weight in the range of 1025 to 1500 with a mixture comprising 20 to 90% by weight of water and 10 to 80% by weight of at least one member of the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane and acetonitrile at a temperature in the range of about 180.degree. to 300.degree. C. and below the critical temperature(s) of said member(s) employed, for at least 0.5 hour in a closed vessel, and separating from said liquid composition any lower density liquid phase present, said liquid product being prepared by cooling said liquid composition to below 100.degree. C., and adding to said liquid composition triethyl phosphate or dimethylsulfoxide in an amount to constitute 10 to 200% by weight of said polymer, to form said liquid product, followed by drying.
A process for making a coated article which comprises applying to a substrate a liquid product prepared from a liquid composition of a perfluorinated ion exchange polymer having --SO.sub.3 M functional groups wherein M is H, Na, K or NR.sub.4, and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, in a liquid medium, said liquid composition being liquid at room temperature, said liquid composition being prepared by the process comprising contacting a said polymer having an equivalent weight in the range of 1025 to 1500 with a mixture comprising 20 to 90% by weight of water and 10 to 80% by weight of at least one member of the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane and acetonitrile at a temperature in the range of about 180.degree. to 300.degree. C. and below the critical temperature(s) of said member(s) employed, for at least 0.5 hour in a closed vessel, and separating from said liquid composition any lower density liquid phase present, said liquid product being prepared by cooling said liquid composition to below 100.degree. C., and adding to said liquid composition 2-ethoxyethanol in an amount to constitute 4 to 60% by volume of the resulting said liquid product, followed by drying.
A process for making a coated article which comprises applying to a substrate a liquid product prepared from a liquid composition of a perfluorinated ion exchange polymer having --SO.sub.3 M functional groups wherein M is H, Na, K or NR.sub.4, and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, in a liquid medium, said liquid composition being liquid at room temperature, said liquid composition being prepared by the process comprising contacting a said polymer having an equivalent weight in the range of 1025 to 1500 with a mixture comprising 20 to 90% by weight of water and 10 to 80% by weight of at least one member of the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane and acetonitrile at a temperature in the range of about 180.degree. to 300.degree. C. and below the critical temperature(s) of said member(s) employed, for at least 0.5 hour in a closed vessel, and separating from said liquid composition any lower density liquid phase present, said liquid product being prepared by removing from said liquid composition by vaporization a portion of said water and at least a portion of said at least one member, and then adding n-propanol to form said liquid product of said polymer in a modified liquid medium, 25 to 40% by weight of said modified liquid medium being water, followed by drying.
A process for repairing a perfluorinated ion exchange membrane which leaks at a defective portion thereof, which process comprises applying to said defective portion a liquid composition of a perfluorinated ion exchange polymer having --SO.sub.3 M functional groups wherein M is H, Na, K or NR.sub.4, and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, in a liquid medium, said liquid composition being liquid at room temperature, said liquid composition being prepared by the process comprising contacting a said polymer having an equivalent weight in the range of 1025 to 1500 with a mixture comprising 20 to 90% by weight of water and 10 to 80% by weight of at least one member of the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane and acetonitrile at a temperature in the range of about 180.degree. to 300.degree. C. and below the critical temperature(s) of said member(s) employed, for at least 0.5 hour in a closed vessel, and separating from said liquid composition any lower density liquid phase present, followed by drying.
A process for repairing a membrane which comprises one or more layers of perfluorinated ion exchange polymer having --SO.sub.3 M and/or --COOM functional groups where M is H, Na, K or NR.sub.4 and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, said membrane having a defective area, which process comprises the steps of:
A process for repairing a perfluorinated ion exchange membrane which leaks at a defective portion thereof, which process comprises applying to said defective portion a liquid product prepared from a liquid composition of a perfluorinated ion exchange polymer having --SO.sub.3 M functional groups wherein M is H, Na, K or NR.sub.4, and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, in a liquid medium, said liquid composition being liquid at room temperature, said liquid cmposition being prepared by the process comprising contacting a said polymer having an equivalent weight in the range of 1025 to 1500 with a mixture comprising 20 to 90% by weight of water and 10 to 80% by weight of at least one member of the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, dimethylene glycol diethyl ether, dioxane and acetonitrile at a temperature in the range of about 180.degree. to 300.degree. C. and below the critical temperature(s) of said member(s) employed, for at least 0.5 hour in a closed vessel, and separating from said liquid composition any lower density liquid phase present, said liquid product being prepared by cooling said liquid composition to below 100.degree. C., and adding to said liquid composition triethyl phosphate or dimethylsulfoxide in an amount to constitute 10 to 200% by weight of said polymer, to form said liquid product, followed by drying.
A process for repairing a perfluorinated ion exchange membrane which leaks at a defective portion thereof, which process comprises applying to said defective portion a liquid product prepared from a liquid composition of a perfluorinated ion exchange polymer having --SO.sub.3 M functional groups wherein M is H, Na, K or NR.sub.4, and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, in a liquid medium, said liquid composition being liquid at room temperature, said liquid composition being prepared by the process comprising contacting a said polymer having an equivalent weight in the range of 1025 to 1500 with a mixture comprising 20 to 90% by weight of water and 10 to 80% by weight of at least one member of the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane and acetonitrile at a temperature in the range of about 180.degree. to 300.degree. C. and below the critical temperature(s) of said member(s) employed, for at least 0.5 hour in a closed vessel, and separating from said liquid composition any lower density liquid phase present, said liquid product being prepared by cooling said liquid composition to below 100.degree. C., and adding to said liquid composition 2-ethoxyethanol in an amount to consitiute 4 to 60% by volume of the resulting said liquid product, followed by drying.
A process for repairing a perfluorinated ion exchange membrane which leaks at a defective portion thereof, which process comprises applying to said defective portion a liquid product prepared from a liquid composition of a perfluorinated ion exchange polymer having --SO.sub.3 M functional groups wherein M is H, Na, K or NR.sub.4, and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, in a liquid medium, said liquid composition being liquid at room temperature, said liquid composition being prepared by the process comprising contacting a said polymer having an equivalent weight in the range of 1025 to 1500 with a mixture comprising 20 to 90% by weight of water and 10 to 80% by weight of at least one member of the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane and acetonitrile at a temperature in the range of about 180.degree. to 300.degree. C. and below the critical temperature(s) of said member(s) employed, for at least 0.5 hour in a closed vessel, and separating from said liquid composition any lower density liquid phase present, said liquid product being prepared by removing from said liquid composition by vaporization a portion of said water and at least a portion of said at least one member, and then adding n-propanol to form said liquid product of said polymer in a modified liquid medium, 25 to 40% by weight of said modified liquid medium being water, followed by drying.
A process for repairing a membrane which comprises one or more layers of perfluorinated ion exchange polymer having --SO.sub.3 M and/or --COOM functional groups where M is H, Na, K or NR.sub.4 and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, said membrane having a defective area, which process comprises the steps of:
A process for repairing a membrane which comprises one or more layers of perfluorinated ion exchange polymer having --SO.sub.3 M and/or --COOM functional groups where M is H, Na, K or NR.sub.4 and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, said membrane having a defective area, which process comprises the steps of:
A process for repairing a membrane which comprises one or more layers of perfluorinated ion exchange polymer having --SO.sub.3 M and/or --COOM functional groups where M is H, Na, K or NR.sub.4 and each R is separately H, CH.sub.3 or C.sub.2 H.sub.5, said membrane having a defective area, which process comprises the steps of:
Dependencies are inferred from the claim text.