| 摘要 |
PURPOSE:To form a porous layer having a uniform distribution of the diameters of open cells by filtering a liq. dispersion of inorg. particles with a supporting layer formed by sintering inorg. particles by forced pressure filtration until the permeation rate becomes constant, and drying and sintering the obtained material. CONSTITUTION:The pipy supporting layer having open cells of 1-2mum diameter is formed by sintering alumina particles having 5mum mean particle diameter. Water and a binder are added to fine alumina powder having 0.5mum mean particle diameter, and the materials are mixed and dispersed by a ball mill to produce a liq. dispersion of particles. The liq. dispersion of particles is forcibly filtered under pressure by the supporting layer 1. Consequently, a porous layer 2 having smaller open cells than the supporting layer is deposited and formed on the inner or outer surface of the supporting layer. The material is then dried and sintered, and a uniform asymmetric membrane with the 20-30mum-thick porous layer 2 and having open cells of 0.2mum diameter over the whole region can be obtained.
|
