TITLE: POLYAMIDE MEMBRANE WITH CONTROLLED SURFACE PROPERTIES AND PROCESS FOR
ITS PRODUCTION
European Patent EP0087228
 B1

ABSTRACT:
Abstract of EP0087228
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
non-solvent 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 non-solvent 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 surfaces 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.
Membranes of this invention are useful in removing metal species from
aqueous streams and in immobilizing enzymes. Membranes of this
invention also have enhanced filtration efficiency over a broad pH
range with very fine contaminants, particularly very fine positively
charged particles, such as asbestos.

INVENTORS:
Gsell, Thomas Charles
Joffee, Irving Brian
Degen, John Peter

APPLICATION NUMBER: EP19830300517
PUBLICATION DATE: 11/26/1986
FILING DATE: 02/02/1983

ASSIGNEE: PALL CORPORATION
INTERNATIONAL CLASSES: B01D71/28; B01D39/16; B01D67/00; B01D71/38; B01D71/40; B01D71/52;
B01D71/56; B01D71/60; B01D71/82; C12N11/08; (IPC1-7): B01D13/04
EUROPEAN CLASSES: C12N11/08; B01D67/00K14; B01D67/00K14B; B01D71/56