Method of producing a filtering material

Abstract

To produce a filtering material for adsorptively capturing very fine particles such as fungus, pollen, virus, bacteria or the like at a high efficiency, an aqueous treatment solution is first prepared by dissolving porous apatite particles of 0.5 to 40% by weight, preferably, 0.5 to 30% by weight and a water soluble glucan of 0.5 to 15% by weight in water. A sheet-shaped raw material is then coated with the treatment solution with the aid of a rotating drum of which part is always dipped in the treatment solution, and thereafter, the sheet-shaped raw material having the treatment solution coated thereon is dried. Alternatively, an aqueous treatment solution prepared by dissolving only a water soluble glucan of 0.5 to 25% by weight in water may be substituted for the aforementioned aqueous treatment solution. In this case, after a sheet-shaped raw material is coated with the treatment solution, porous apatite particles are deposited on the sheet-shaped raw material by employing a dispersing process or a spraying process before the treatment solution coated on the sheet-shaped raw material is kept still wet. Subsequently, the sheet-shaped raw material having the treatment solution coated thereon and the porous apatite particles deposited thereon is dried.

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