| 摘要 |
PURPOSE:To prepare the support sheet of a reverse osmosis liquid separation membrance excellent in reinforcing effect, by a method wherein a membrane forming polymer solution is coated on one surface of a base fabric and a coagulating liquid is contacted with the coated surface and thereafter contacted with the uncoated surface thereof. CONSTITUTION:A base fabric 1 such as knitted fabric or a non-woven fabric comprising a polyamide or a polyester fiber is passed between a knife edge 2 and the support thereof and introduced into a coagulating liquid 5 through a space 9 to be taken up by a rotary drum 6. During this time, a solution 4 containing a polymer such as polysulfone or polysulfonamide is coated on the base fabric at the nip of the knife edge 2 and the support thereof and the speed of the base fabric is regulated so as to impregnate the base fabric 1 with the solution 4 during a time when the base fabric 1 is passed through the space 9. In the next stage, the base fabric 1 is conveyed through the coagulating liquid 5 so as to contact the one surface thereof with a smooth flat plate 7 in said coagulating liquid 5 to selectively coagulate from the coated surface side liquid 5 and support sheet of a reverse osmosis liquid separation membrane consisting of a microporous polymer membrane of which theaverage pore size is 50Angstrom -50mu and the void ratio is 50-90% and a support sheet can be prepared. |
