Abstract: A process for producing an electrodeposited copper foil, comprising electrodepositing a copper foil from an electrolyte containing copper sulfate dissolved therein, in which said electrolyte contains a small amount of lead (Pb) ions, which comprises adding a salt of a metal of Group IIA of the periodic table to the electrolyte in an amount of 10 to 150 mols per mol of lead (Pb) ions contained in the electrolyte so that the lead (Pb) ions contained in the electrolyte react with the metal of Group IIA of the periodic table to thereby form an insoluble composite substance to precipitate, the insoluble composite substance followed by removing it from the electrolyte and forming an electrodeposited copper foil in the electrolyte having the lead (Pb) ions removed therefrom.

Abstract: A method employed to dry a copper foil having been subjected to various surface treatments, which method comprises irradiating at least one surface-treated side of the copper foil with near infrared rays to dry the copper foil, and an apparatus suitable to the method. The drying of the copper foil having undergone surface treatments can be accomplished by a simple apparatus with low electric power while controlling the heating of the surface of the copper foil so that the drying temperature can be held at 100° C. or higher at which a eutectic alloying of rust preventive metal and copper foil, for example, alloying (brass formation) of zinc and copper on the surface of the copper foil is effected.

Abstract: A method employed to dry a copper foil having been subjected to various surface treatments, which method comprises irradiating at least one surface-treated side of the copper foil with near infrared rays to dry the copper foil, and an apparatus suitable to the method. The drying of the copper foil having undergone surface treatments can be accomplished by a simple apparatus with low electric power while controlling the heating of the surface of the copper foil so that the drying temperature can be held at 100° C. or higher at which a eutectic alloying of rust preventive metal and copper foil, for example, alloying (brass formation) of zinc and copper on the surface of the copper foil is effected.

Abstract: A water purifier consisting essentially of manganese dioxide particles having a 20 to 48 mesh size and macroscopic pores which are so large in size as to permit passage of water therethrough. The particles may have active sites of needle-like or columnar crystals of manganese dioxide on the surfaces thereof. A method for making such water purifier is also described.

Abstract: A water purifier consisting essentially of manganese dioxide particles having a 20 to 48 mesh size and macroscopic pores which are so large in size as to permit passage of water therethrough. The particles may have active sites of needle-like or columnar crystals of manganese dioxide on the surfaces thereof. A method for making such water purifier is also described.