PRODUCTION OF ALUMINA-BASED POROUS MATERIAL

摘要

PURPOSE:To obtain an alumina-based porous material having uniform pore diameters and high porosity, slightly damaging in producing a porous material from alumina fine powder using a polyvinyl acetal-based resin as a binder, by preparing the alumina fine powder as a mixture of fine powder having specific large particle diameters and specific small particle diameters in a spe cific ratio. CONSTITUTION:100 pts.wt. alumina fine powder (A1 for short) having 50-100mu average particle diameter is blended with 40-200 pst.wt. alumina fine powder (A2 for short) having 0.5-5mu average particle diameter to give mixed powder. The mixed powder is blended with PVA and a pore forming material and reacted in the presence of a crosslinking agent to give a molded article, which is washed with water and the pore forming material is removed to give an alumina-based porous material. In the operation, when the amount of the powder A2 in the mixed powder is too small, the powder A1 is settled and separated in the reaction dope and when the amount of the powder A2 is too large, the powder A2 is secondarily aggregated and a uniform porous material is not obtained in both the cases.