Metallic foil manufacturing method and cathode for manufacturing metallic foil
Provided are a metallic foil manufacturing method in which a metallic film electrodeposited by electrolysis on the surface of an electrodeposition surface of a cathode is peeled off to form a metallic foil, and the electrodeposition surface used therein is obtained by subjecting a roughened surface, which results from roughening a smoothed surface made of titanium or titanium alloy using a blast treatment, etc., to an oxidation treatment selected from thermal oxidation, anodic oxidation (preferably anodic oxidation carried out while moving the anodic oxidation solution), or a combination treatment of thermal oxidation and anodic oxidation so that the electrodeposition surface has an oxidation layer with a thickness of 30 to 250 nm on the uppermost layer and has a surface roughness RZJIS of 4 to 10 μm.
1. A method for manufacturing a metallic foil comprising
forming an electrodeposition surface on a surface of a cathode by:
performing a roughening treatment on a smoothed surface made of titanium or titanium alloy to form a roughened surface; and
performing an oxidation treatment selected from the group consisting of thermal oxidation, anodic oxidation, and a combination treatment of thermal oxidation and anodic oxidation, the oxidation treatment being performed on the roughened surface to form an oxidation layer with a thickness of 30 nm to 250 nm on an outermost layer,
the electrodeposition surface having:
a center portion in a width direction of the cathode, the center portion corresponding to a product portion of the metallic foil and having a surface roughness R ZJIS of 4 μm to 10 μm; and
adjacent portions on both sides of the center portion, the adjacent portions having a surface roughness R ZJIS of 2.5 μm or less,
electrodepositing a metallic film by electrolysis on the electrodeposition surface, and peeling the metallic film from the electrodeposition surface to obtain the metallic foil.
2. The method for manufacturing a metallic foil according to claim 1 ,
wherein the oxidation treatment is anodic oxidation and the anodic oxidation is performed while moving an anodic oxidation solution in contact with the roughened surface.
3. The method for manufacturing a metallic foil according to claim 2 ,
wherein the anodic oxidation is performed while moving the anodic oxidation solution in contact with the roughened surface by one selected from the group consisting of a means for applying a liquid flow, a means for applying ultrasonic waves, and a combination of the means for applying a liquid flow and the means for applying ultrasonic waves.
4. The method for manufacturing a metallic foil according to claim 1 , wherein
an immersing treatment is performed on the roughened surface as a pre-treatment for the oxidation treatment, the immersing treatment being selected from the group consisting of an immersing treatment in an alkaline solution, an immersing treatment in a strongly acidic solution, and a combination treatment of the immersing treatment in the alkaline solution and the immersing treatment in the strongly acidic solution.
5. The method for manufacturing a metallic foil according to claim 1 , wherein the roughening treatment is a blast treatment.
6. The method for manufacturing a metallic foil according to claim 1 , wherein the electrodeposition surface has a ratio of a width of each adjacent portion to a width of the center portion of 0.1% to 10%.