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US 4,707,266 AGranted
Polyamide membrane with controlled surface properties
AssigneePall Corporation
InventorsPeter J. Degen, Irving B. Joffee, Thomas C. Gsell
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AssigneePall Corporation
InventorsPeter J. Degen, Irving B. Joffee, Thomas C. Gsell
Estimating the term…
Surface modified, skinless, hydrophilic, microporous, polyamide membranes with controlled surface properties are prepared by the steps of preparing a casting solution comprised of (A) a casting resin system comprised of (a) an alcohol-insoluble polyamide resin, and (b) a water-soluble membrane surface modifying polymer having functional polar groups and a molecular weight of 10,000 or greater, and (B) a solvent system in which the casting resin system is soluble; inducing nucleation of the casting solution by controlled addition of a nonsolvent for the casting resin system under controlled conditions to obtain a visible precipitate of casting resin system particles, thereby forming a casting composition; spreading the casting composition on a substrate to form a thin film; contacting and diluting the film of the casting composition with a liquid nonsolvent system for the casting resin system, thereby precipitating the casting resin system from the casting composition in the form of a thin, skinless, hydrophilic, surface modified, microporous, polyamide membrane; and washing and drying the membrane. The membranes of this invention are characterized by having fine pore ratings, the surface properties thereof being substantially controlled by functional polar groups of a membrane surface modifying polymer and having the capability, through the functional polar groups of the modifying polymer, of reacting or interacting with particulates and/or nonparticulates in a fluid.
A process for preparing a surface modified, skinless, hydrophilic, microporous, alcohol-insoluble polyamide membrane with controlled pore surface properties, capable of reacting or interacting in a controlled manner with (a) particulate matter in a fluid, (b) non-particulate matter in a fluid, or (c) both (a) and (b) and that is readily wetted by water, which comprises:
A process for preparing a surface modified, skinless, hydrophilic, microporous, alcohol-insoluble polyhexamethylene adipamide resin membrane with controlled pore surface properties, capable of reacting or interacting in a controlled manner with (a) particulate matter in a fluid, (b) non-particulate matter in a fluid, or (c) both (a) and (b) and that is readily wetted by water, which comprises:
A surface modified, skinless, hydrophilic, microporous, alcohol-insoluble polyamide membrane derived from an alcohol-insoluble hydrophobic polyamide resin having a ratio CH.sub.2 :NHCO of methylene CH.sub.2 to amide NHCO groups within the range of from about 5:1 to about 7:1, said membrane having an integral microstructure and characterized by (1) the surface properties thereof being substantially controlled by functional polar groups of a membrane surface modifying polymer having a molecular weight of 20,000 or greater, said functional polar groups selected from the group consisting of hydroxyl, carboxyl, and amino, or a non-reacting combination thereof, (2) said membrane surface modifying polymer being homogeneously distributed in said membrane, and (3) having the capability of reacting or interacting in a controlled manner with (a) particulate matter in a fluid, (b) non-particulate matter in a fluid, or (c) both (a) and (b).
An integral surface modified, skinless, hydrophilic, microporous, alcohol-insoluble polyamide membrane derived from about 80 to about 99.9% of an alcohol-insoluble hydrophobic polyamide resin having a ratio CH.sub.2 :NHCO of methylene CH.sub.2 to amide NHCO groups within the range of from about 5:1 to about 7:1 and from about 20 to about 0.1% of a membrane surface modifying polymer having functional polar groups, said functional polar groups selected from the group consisting of hydroxyl, carboxyl, and amino, or a nonreacting combination thereof, and a molecular weight of 20,000 or greater, said membrane having an integral microstructure and characterized by (1) the surface properties thereof being substantially controlled by functional polar groups of the membrane surface modifying polymer, (2) said membrane surface modifying polymer being homogeneously distributed in said membrane, and (3) having the capability of reacting or interacting in a controlled manner with (a) particulate matter in a fluid, (b) non-particulate matter in a fluid, or (c) both (a) and (b).
A surface modified, skinless, hydrophilic, microporous, alcohol-insoluble polyamide membrane derived from an alcohol-insoluble hydrophobic polyamide resin having a ratio CH.sub.2 :NHCO of methylene CH.sub.2 to amide NHCO groups within the range of from about 5:1 to about 7:1, said membrane having an integral microstructure and characterized by (1) the surface properties thereof being substantially controlled by functional polar groups of a membrane surface modifying polymer having a molecular weight of 20,000 or greater, said functional polar groups comprising hydroxyl, (2) said membrane surface modifying polymer being homogeneously distributed in said membrane, and (3) having the capability of reacting or interacting in a controlled manner with (a) particulate matter in a fluid, (b) non-particulate matter in a fluid, or (c) both (a) and (b).
A surface modified, skinless, hydrophilic, microporous, alcohol-insoluble polyamide membrane derived from an alcohol-insoluble hydrophobic polyamide resin having a ratio CH.sub.2 :NHCO of methylene CH.sub.2 to amide NHCO groups within the range of from about 5:1 to about 7:1, said membrane having an integral microstructure and characterized by (1) the surface properties thereof being substantially controlled by functional polar groups of a membrane surface modifying polymer having a molecular weight of 20,000 or greater, said functional polar groups comprising carboxyl, (2) said membrane surface modifying polymer being homogeneously distributed in said membrane, and (3) having the capability of reacting or interacting in a controlled manner with (a) particulate matter in a fluid, (b) non-particulate matter in a fluid, or (c) both (a) and (b).
A surface modified, skinless, hydrophilic, microporous, alcohol-insoluble polyamide membrane derived from an alcohol-insoluble hydrophobic polyamide resin having a ratio CH.sub.2 :NHCO of methylene CH.sub.2 to amide NHCO groups within the range of from about 5:1 to about 7:1, said membrane having an integral microstructure and characterized by (1) the surface properties thereof being substantially controlled by functional polar groups of a membrane surface modifying polymer having a molecular weight of 20,000 or greater, said functional polar groups comprising amino, (2) said membrane surface modifying polymer being homogeneously distributed in said membrane, and (3) having the capability of reacting or interacting in a controlled manner with (a) particulate matter in a fluid, (b) non-particulate matter in a fluid, or (c) both (a) and (b).
Dependencies are inferred from the claim text.