| 摘要 |
PURPOSE:To obtain an asymmetric ceramic film having superior porosity and durability by preparing a porous ceramic support and successively forming a fine middle layer having a smaller pore diameter than the base material and a thin film having a smaller pore diameter than the middle layer on the surface of the support. CONSTITUTION:A fine middle layer 4 composed of SnO2, TiO2, ZrO2 or CeO2 particles of <=500Angstrom particle size is formed on the surface of an active layer 3 formed on the surface of a porous ceramic support. A thin film 5 composed of SnO2, TiO2, ZrO2 or CeO2 particles of <=300Angstrom particle size is then formed on the surface of the middle layer 4. At this time, a sol applied to the support is converted into gel and this gel is calcined at 400-800 deg.C to form the middle layer 4 and the thin film 5 is formed by calcination at 300-600 deg.C. An asymmetric film having superior porosity, durability and high permeability is obtd. |
