초록 ▼

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 ami

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. water having no significant ionic content, to produce a membrane suitable for use in filtering ultra pure (18 megohm-cm resistivity) water for use in producing electronic devices. Such a membrane exhibits an advantageously low “flush-out”time compared to known cationic charge modified microporous membranes and unmodified microporous membranes.

대표청구항 ▼

A process for the filtration of liquids having particulate contaminants therein, comprising passing the liquid through a hydrophilic cationic charge modified microporous filter membrane comprising: a hydrophilic organic polymeric microporous filter membrane having an internal micro-structure through

A process for the filtration of liquids having particulate contaminants therein, comprising passing the liquid through a hydrophilic cationic charge modified microporous filter membrane comprising: a hydrophilic organic polymeric microporous filter membrane having an internal micro-structure throughout said membrane, and a charge modifying amount of a cationic charge modifying agent bonded to substantially all of the membrane micro-structure without substantial pore size reduction or pore blockage, through an aliphatic polyepoxide cross-linking agent having a molecular weight of less than about 500, wherein the charge and modifying agent is selected from the group consisting of: (i) aliphatic amines which are polyamines having at least one primary amine or at least two secondary amines; and (ii) aliphatic amines having at least one secondary amine and a carboxyl or hydroxyl substituent.