초록 ▼

Cellulose acetate containing membranes which have pore diameters of about 10 to 1000 Åare modified by reacting these membranes (a) with (b) an at least difunctional compound, e.g. cyanuric chloride, (c) a polyfunctional oligomer or polymer, e.g. polyethyleneimine, and then with (d) a compound which

Cellulose acetate containing membranes which have pore diameters of about 10 to 1000 Åare modified by reacting these membranes (a) with (b) an at least difunctional compound, e.g. cyanuric chloride, (c) a polyfunctional oligomer or polymer, e.g. polyethyleneimine, and then with (d) a compound which contains at least one ionic group and one group capable of reaction with component (c). Reactant (d) is necessary only if the polyfunctional component (c) does not already contain sufficient ionic groups. The novel membranes are suitable for ultrafiltration and can be used for example for separating monovalent ions of low ionic weight from polyvalent ions of low or relatively high ionic weight of from monovalent ions of relatively high ionic weight and for separating ionic compounds (salts) from non-ionic (organic) compounds or from ionic compounds which have a different molecular weight or opposite charge. They can be used for example for separating salts from organic compounds (dyes) or in waste-water treatment.

대표청구항 ▼

A porous, modified cellulose acetate membrane having a structure suitable for ultrafiltration and reverse osmosis, said membrane being prepared by a sequence of chemical reactions consisting essentially of steps (1) to (3), wherein: step (1) is reacting (a) a cellulose acetate containing membrane ha

A porous, modified cellulose acetate membrane having a structure suitable for ultrafiltration and reverse osmosis, said membrane being prepared by a sequence of chemical reactions consisting essentially of steps (1) to (3), wherein: step (1) is reacting (a) a cellulose acetate containing membrane having a pore diameter in the range of from 10 to 1000 Å, with (b) an organic compound which contains at least one group (b1) capable of reaction with hydroxyl groups of the membrane (a), and at least one group (b2) capable of reaction with component (c), to bond the hydroxyl groups to a group (b1), such that a membrane obtained from step (1) has at least one reactive group (b2), step (2) is reacting group (b2) of said membrane with (c) a polyfunctional linear or branched polymer containing functional groups (c1) and (c2), to bond group (b2) to group (c1), and thereby introduce said polymer into said membrane, and step (3) is reacting (d) a compound which contains at least one ionic group and at least one group (d1) capable of reaction with group (c2), provided that said polyfunctional linear or branched polymer (c) itself does not already possess sufficient ionic groups, to bond group (d1) to group (c2) to form a membrane containing said at least one ionic group.