| 摘要 |
PURPOSE:To obtain a hollow yarn reverse osmosis membrane hard to generate not only densification but also the deterioration in capacity even in long-time use, by containing a water-insoluble inorg. powder with a specific particle size or less in a membrane in a specific ratio or more in a dispersed state. CONSTITUTION:A water-insoluble inorg. powder such as a kaolin powder, talc or diatomaceous earth surface-treated with epoxy silane is mixed and dispersed throughout a solution of a film forming polymer such as cellulose acetate and the resulting dispersion is filtered through a sintered metal filter with a pore size of 20mum to remove a solid with a particle size of 20mum or more and molded into a hollow yarn form by an arbitrary molding method and, if necessary, post-treatment is applied to the molded one to finish a hollow yarn reverse osmosis membrane. In this case, it is necessary to contain the water-insoluble inorg. powder in a ratio of 3,000ppm or more on the basis of the polymer for constituting the reverse osmosis membrane.
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