Development of smectite basedˆlm 蛯名 武雄(Takeo EBINA) Smectite-basedˆlm``Claist '' was developed. Layered smectite crystals are orderly densely stacked and added organic polymer acts as a binder. Puriˆed bentonite, and synthetic smectite were used because of their goodˆlm formability. Theˆlm has superior heat-resistance and gas barrier performance. Transparentˆlms were also successfully made from synthetic smectite and transparent organic polymer. Theˆlms are hopeful for electric devices including display, hydrogen gas tight sheet, solar cell back sheet, gasket and packing, functional wallpaper, and so on.