Electrode material for aluminum electrolytic capacitor, and method for producing same

1. An electrode material for an electrolytic capacitor, comprising, as constituent elements, a sintered body of a powder of at least one member selected from the group consisting of aluminum and aluminum alloys, and an aluminum foil substrate supporting the sintered body thereon, wherein

(1) the powder has an average particle size D 50 of 0.5 to 100 μm,

(2) the sintered body is formed on one surface or both surfaces of the aluminum foil substrate and has a total thickness of 10 to 1,000 μm,

(3) the porosity of the sintered body is 35 to 49% by volume, and

(4) the sintered body is obtained by applying a rolling process to a film made from a composition comprising a powder of at least one member selected from the group consisting of aluminum and aluminum alloys, and subsequently sintering the film.

2. A method for producing an electrode material for an aluminum electrolytic capacitor, comprising the steps of:

Step 1: forming a film made from a composition comprising a powder of at least one member selected from the group consisting of aluminum and aluminum alloys on an aluminum foil substrate; wherein

(1) the powder has an average particle size D 50 of 0.5 to 100 μm,

(2) the film is formed on one surface or both surfaces of the aluminum foil substrate, and the total thickness of the film or films is more than 10 μm but not exceeding 1,150 μm,

Step 2: rolling the film, after Step 1, in such a manner that the film has a reduction within a range that exceeds 0% but is 15% or less, and that when the rolled film is sintered, the sintered body has a porosity of 35 to 49% by volume, and

Step 3: sintering the film, after Step 2, at a temperature in the range of 560 to 660° C.,

the method being free from an etching treatment.

3. The production method according to claim 2 , wherein the rolling in step 2 is performed in such a manner that the film has a reduction with a range of 4% to 15%.