COMPOSITE SEMIPERMEABLE MEMBRANE AND MANUFACTURING METHOD FOR THE SAME, AND SPIRAL TYPE SEPARATION MEMBRANE

摘要

PROBLEM TO BE SOLVED: To provide a thin-type composite semipermeable membrane which has a practical salt-blocking rate and a permeation flow and a manufacturing method for the same, and a spiral type separation membrane element which has a practical salt-blocking rate and is excellent in water treatment efficiency.SOLUTION: A manufacturing method for a composite semipermeable membrane of this invention, which comprises the step of forming a skin layer containing a polyamide resin on the surface of a porous support by bringing an amine solution containing a polyfunctional amine component in contact with the porous support while the porous support having a polymer porous layer on one side of an unwoven fabric is delivered from a supply roll, and by bringing the amine solution on the porous support in contact with an organic solution containing a polyfunctional acid halide component to perform interfacial polymerization, is characterized in that the unwoven fabric has a thickness of 50-90 μm and brings the amine solution in contact with the porous support when a drop rate in the percentage of moisture content of the porous support is within 15% in the case where the percentage of moisture content of the porous support on delivery from the supply roll is 100%.SELECTED DRAWING: None