| 摘要 |
PURPOSE:To obtain the titled repeatedly usable porous material useful for precise separation, filtration, etc., having excellent high-temperature stability, strength, heat (shock) resistance and chemical resistance, by forming SiC, Si3N4, etc., in such a way that the formed material has through pore diameter and porosity in specific ranges. CONSTITUTION:For example, SiC powder and carbon powder are molded by the use of a binder to give a molded article, which is reacted with Si at >=1,500 deg.C, SiC is further formed and unreacted Si is left to give SiC sintered material or the materials are treated in the same way as the above-mentioned method by using Y2O3 or Al2O3 as an auxiliary agent to give Si3N4 sintered material similarly. Then the ceramic sintered material such as SiC or Si3N4 having remained Si is treated with a halogen, hydrogen halide or an alkali solution to remove the remaining Si to give the titled porous material comprising SiC, Si3N4, etc., having 40Angstrom -20mu through pore diameter and >=3% porosity.
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