COMPOSITE REVERSE OSMOSIS MEMBRANE AND PROCESS FOR PREPARING THE SAME

摘要

A composite reverse osmosis membrane comprising a polyamide skin layer provided on a porous support, wherein the contact angle of water on the surface of the polyamide skin layer is set to be not more than 45 DEG . This membrane has excellent salt cut-off property and high water permeability. It can be prepared by coating a porous support with a solution A containing a compound having two or more reactive amino groups to form a layer, bringing a solution B containing a polyfunctional acid halide compound into contact with this layer, and then bringing a solution C containing a polyfunctional acid halide compound and having a concentration higher than that of the solution B into contact with the above layer to form a polyamide skin layer. The concentration of the polyfunctional acid halide compound in the solution C is preferably at least 1.2 times higher than the concentration of the polyfunctional halide compound in the solution B.