Abstract: A cationic charge modified microporous membrane is provided. The membrane comprises a hydrophilic organic polymeric microporous membrane having bonded thereto, through a cross-linking agent, a charge modifying amount of a cationic charge modifying agent. The charge modifying agent is an aliphatic amine or polyamine, preferably tetraethylene pentamine, and the cross-linking agent is an aliphatic polyepoxide having a molecular weight of less than about 500, preferably 1, 4 butanediol diglycidyl ether. The microporous membrane is preferably nylon. The process for applying the charge modifying agent to the membrane, preferably comprises contacting the membrane with an aqueous solution of the charge modifying agent and then contacting the membrane with a substantially aqueous solution of the cross-linking agent. The preferred process uses high purity water, i.e.

Abstract: A cationic charge modified microporous membrane is provided. The membrane comprises a hydrophilic organic polymeric microporous membrane having bonded thereto, through a cross-linking agent, a charge modifying amount of a cationic charge modifying agent. The charge modifying agent is an aliphatic amine or polyamine, preferably tetraethylene pentamine, and the cross-linking agent is an aliphatic polyepoxide having a molecular weight of less than about 500, preferably 1, 4 butanediol diglycidyl ether. The microporous membrane is preferably nylon. The process for applying the charge modifying agent to the membrane, preferably comprises contacting the membrane with an aqueous solution of the charge modifying agent and then contacting the membrane with a substantially aqueous solution of the cross-linking agent. The preferred process uses high purity water, i.e.

Abstract: A reinforced laminated filtration membrane is provided. The membrane comprises:(a) a porous reinforcing web impregnated with a polymeric microporous inner membrane; and(b) at least one polymeric microporous outer membrane laminated to each side of the impregnated web, wherein the pore size of the inner membrane is greater than the pore size of the outer membranes. Preferably, the polymeric membranes are nylon.

Abstract: A process for producing an integral single layer polymeric microporous filter membrane within which a reinforcing web is embedded. The process comprises passing a reinforcing web through a first reservoir of casting solution of polymer and then simultaneously calendering both sides of the coated web to provide for penetration of the solution into the web and to remove substantially all entrapped air from the web. The calendered reinforcing web is then passed through a second reservoir of casting solution and then through a quenching bath to form micropores throughout the coatings.

Abstract: A cationic charge modified microporous membrane is provided. The membrane comrises a hydrophilic organic polymeric microporous membrane having bonded thereto, through a cross-linking agent, a charge modifying amount of a cationic charge modifying agent. The charge modifying agent is an aliphatic amine or polyamine, preferably tetraethylene pentamine, and the cross-linking agent is an aliphatic polyepoxide having a molecular weight of less than about 500, preferably 1, 4 butanediol diglycidyl ether. The microporous membrane is preferably nylon. The process for applying the charge modifying agent to the membrane, preferably comprises contacting the membrane with an aqueous solution of the charge modifying agent and then contacting the membrane with a substantially aqueous solution of the cross-linking agent. The preferred process uses high purity water, i.e.